Secretome of Hypoxia-Preconditioned Mesenchymal Stem Cells Enhance Angiogenesis in Diabetic Rats with Peripheral Artery Disease Sazli, Brama Ihsan In: 2023. @article{noKey,
title = {Secretome of Hypoxia-Preconditioned Mesenchymal Stem Cells Enhance Angiogenesis in Diabetic Rats with Peripheral Artery Disease},
author = {Sazli, Brama Ihsan},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10227841/},
doi = {https://doi.org/10.5455/medarh.2023.77.90-96},
year = {2023},
date = {2023-01-01},
abstract = {Background:
Lower limb peripheral artery disease (PAD) is the main risk of diabetes mellitus which result to high mortality rate. Approximately, 50% of patients who receive several treatments have passed away or lost limbs at a year’s follow-up. Secretome of hypoxia mesenchymal stem cells (S-MSCs) contains several active soluble molecules from hypoxia MSCs (H-MSCs) that capable inducing anti-inflammatory and vascular regeneration in PAD.
Objective:
In this study, we investigated the therapeutic potential of S-MSCs in improving dynamic function and angiogenesis of PAD diabetic rats.
Methods:
The PAD was established by the incision from the groin to the inner thigh and distal ligation of femoral arteries in rats with diabetes. Rats were administered with 200 µL and 400 µL S-MSCs that successfully filtrated using tangential flow filtration (TFF) system based on various molecular weight cut-off categories intravenously. ELISA assay was used to analyze the cytokines and growth factors contained in S-MSCs. Tarlov score were examined at day 1, 3, 5, 7, 10 and 14. The rats were sacrificed at day 14 and muscle tissues were collected for immunohistochemistry (IHC) and gene expression analysis.
Results:
ELISA assay showed that S-MSCs provides abundant level of VEGF, PDGF, bFGF, IL-10 and TGFβ. In vivo administration of S-MSCs remarkably enhanced the Tarlov score. S-MSCs improved angiogenesis through enhancing VEGF gene expression and significantly increasing CD31 positive area in muscle tissue of PAD diabetic rats.
Conclusion:
Our findings suggest that S-MSCs could improves dynamic function and angiogenesis in PAD diabetic rats.},
keywords = {µPULSE},
pubstate = {published},
tppubtype = {article}
}
Background:
Lower limb peripheral artery disease (PAD) is the main risk of diabetes mellitus which result to high mortality rate. Approximately, 50% of patients who receive several treatments have passed away or lost limbs at a year’s follow-up. Secretome of hypoxia mesenchymal stem cells (S-MSCs) contains several active soluble molecules from hypoxia MSCs (H-MSCs) that capable inducing anti-inflammatory and vascular regeneration in PAD.
Objective:
In this study, we investigated the therapeutic potential of S-MSCs in improving dynamic function and angiogenesis of PAD diabetic rats.
Methods:
The PAD was established by the incision from the groin to the inner thigh and distal ligation of femoral arteries in rats with diabetes. Rats were administered with 200 µL and 400 µL S-MSCs that successfully filtrated using tangential flow filtration (TFF) system based on various molecular weight cut-off categories intravenously. ELISA assay was used to analyze the cytokines and growth factors contained in S-MSCs. Tarlov score were examined at day 1, 3, 5, 7, 10 and 14. The rats were sacrificed at day 14 and muscle tissues were collected for immunohistochemistry (IHC) and gene expression analysis.
Results:
ELISA assay showed that S-MSCs provides abundant level of VEGF, PDGF, bFGF, IL-10 and TGFβ. In vivo administration of S-MSCs remarkably enhanced the Tarlov score. S-MSCs improved angiogenesis through enhancing VEGF gene expression and significantly increasing CD31 positive area in muscle tissue of PAD diabetic rats.
Conclusion:
Our findings suggest that S-MSCs could improves dynamic function and angiogenesis in PAD diabetic rats. |
Structural and functional analyses of Pcal_0917, an α-glucosidase from hyperthermophilic archaeon Pyrobaculum calidifontis Atta Muhammad, Majida In: 2023. @article{noKey,
title = {Structural and functional analyses of Pcal_0917, an α-glucosidase from hyperthermophilic archaeon Pyrobaculum calidifontis},
author = {Atta Muhammad, Majida},
url = {https://doi.org/10.1016/j.ijbiomac.2023.125446},
doi = {https://doi.org/10.1016/j.ijbiomac.2023.125446},
year = {2023},
date = {2023-01-01},
abstract = {Genome analysis of Pyrobaculum calidifontis revealed the presence of α-glucosidase (Pcal_0917) gene. Structural analysis affirmed the presence of signature sequences of Type II α-glucosidases in Pcal_0917. We have heterologously expressed the gene and produced recombinant Pcal_0917 in Escherichia coli. Biochemical characteristics of the recombinant enzyme resembled to that of Type I α-glucosidases, instead of Type II. Recombinant Pcal_0917 existed in a tetrameric form in solution and displayed highest activity at 95 °C and pH 6.0, independent of any metal ions. A short heat-treatment at 90 °C resulted in a 35 % increase in enzyme activity. A slight structural shift was observed by CD spectrometry at this temperature. Half-life of the enzyme was >7 h at 90 °C. Pcal_0917 exhibited apparent Vmax values of 1190 ± 5 and 3.9 ± 0.1 U/mg against p-nitrophenyl α-D-glucopyranoside and maltose, respectively. To the best of our knowledge, Pcal_0917 displayed the highest ever reported p-nitrophenyl α-D-glucopyranosidase activity among the characterized counterparts. Moreover, Pcal_0917 displayed transglycosylation activity in addition to α-glucosidase activity. Furthermore, in combination with α-amylase, Pcal_0917 was capable of producing glucose syrup from starch with >40 % glucose content. These properties make Pcal_0917 a potential candidate for starch hydrolyzing industry.},
keywords = {µPULSE},
pubstate = {published},
tppubtype = {article}
}
Genome analysis of Pyrobaculum calidifontis revealed the presence of α-glucosidase (Pcal_0917) gene. Structural analysis affirmed the presence of signature sequences of Type II α-glucosidases in Pcal_0917. We have heterologously expressed the gene and produced recombinant Pcal_0917 in Escherichia coli. Biochemical characteristics of the recombinant enzyme resembled to that of Type I α-glucosidases, instead of Type II. Recombinant Pcal_0917 existed in a tetrameric form in solution and displayed highest activity at 95 °C and pH 6.0, independent of any metal ions. A short heat-treatment at 90 °C resulted in a 35 % increase in enzyme activity. A slight structural shift was observed by CD spectrometry at this temperature. Half-life of the enzyme was >7 h at 90 °C. Pcal_0917 exhibited apparent Vmax values of 1190 ± 5 and 3.9 ± 0.1 U/mg against p-nitrophenyl α-D-glucopyranoside and maltose, respectively. To the best of our knowledge, Pcal_0917 displayed the highest ever reported p-nitrophenyl α-D-glucopyranosidase activity among the characterized counterparts. Moreover, Pcal_0917 displayed transglycosylation activity in addition to α-glucosidase activity. Furthermore, in combination with α-amylase, Pcal_0917 was capable of producing glucose syrup from starch with >40 % glucose content. These properties make Pcal_0917 a potential candidate for starch hydrolyzing industry. |
The Role of Mesenchymal Stem Cell Secretome in the Inflammatory Mediators and the Survival Rate of Rat Model of Sepsis Sari et al, Mutiara Indah Sari In: 2023. @article{noKey,
title = {The Role of Mesenchymal Stem Cell Secretome in the Inflammatory Mediators and the Survival Rate of Rat Model of Sepsis},
author = {Sari et al, Mutiara Indah Sari},
url = {https://www.mdpi.com/2227-9059/11/8/2325},
doi = {https://doi.org/10.3390/biomedicines11082325},
year = {2023},
date = {2023-01-01},
abstract = {In sepsis, simultaneously elevated levels of pro-inflammatory cytokines and interleukin (IL)-10 indicate immune response dysregulation, increasing the mortality of the host. As mesenchymal stem cell (MSC) secretome is known to have immunomodulatory effects, we aim to assess the role of MSC secretome in the inflammatory mediators (NF-κB p65 and p50, TNF-α, IL-10) and the survival rate of a rat model of sepsis. In this study, forty-eight male Rattus norvegicus rats were divided into one sham group and three groups with sepsis induction: the control group and the sepsis-induced rat groups treated with 150 μL (T1) and 300 μL (T2) of secretome. The survival rate was observed per 6 h for 48 h and plotted using the Kaplan–Meier method. Compared to the control group, T2 showed a significant decrease in the relative expression of NF-κB and the serum TNF-α level, and a significant increase in the serum IL-10 level. Meanwhile, T1 showed a significant decrease in the serum TNF-α level compared to the control group. The Kaplan–Meier Log Rank test did not show significance in the distribution of survival between T1, T2, and the control group. However, from the 18th to the 36th hour, the survival rate of T2 was lower than the survival rate of the control group and T1, with a noticeable difference between T2 and the control group, as well as T1 at the 36th hour. At the 42nd hour, the survival rate of T2 was the same as the control group and remained lower than T1. In conclusion, MSC secretome regulated the inflammatory mediators in rat model of sepsis, with a dose of 150 μL being more effective.},
keywords = {µPULSE},
pubstate = {published},
tppubtype = {article}
}
In sepsis, simultaneously elevated levels of pro-inflammatory cytokines and interleukin (IL)-10 indicate immune response dysregulation, increasing the mortality of the host. As mesenchymal stem cell (MSC) secretome is known to have immunomodulatory effects, we aim to assess the role of MSC secretome in the inflammatory mediators (NF-κB p65 and p50, TNF-α, IL-10) and the survival rate of a rat model of sepsis. In this study, forty-eight male Rattus norvegicus rats were divided into one sham group and three groups with sepsis induction: the control group and the sepsis-induced rat groups treated with 150 μL (T1) and 300 μL (T2) of secretome. The survival rate was observed per 6 h for 48 h and plotted using the Kaplan–Meier method. Compared to the control group, T2 showed a significant decrease in the relative expression of NF-κB and the serum TNF-α level, and a significant increase in the serum IL-10 level. Meanwhile, T1 showed a significant decrease in the serum TNF-α level compared to the control group. The Kaplan–Meier Log Rank test did not show significance in the distribution of survival between T1, T2, and the control group. However, from the 18th to the 36th hour, the survival rate of T2 was lower than the survival rate of the control group and T1, with a noticeable difference between T2 and the control group, as well as T1 at the 36th hour. At the 42nd hour, the survival rate of T2 was the same as the control group and remained lower than T1. In conclusion, MSC secretome regulated the inflammatory mediators in rat model of sepsis, with a dose of 150 μL being more effective. |
An ependymal cell census identifies heterogeneous and ongoing cell maturation in the adult mouse spinal cord that changes dynamically on injury Albors, Aida Rodrigo, et al. In: 2023. @article{noKey,
title = {An ependymal cell census identifies heterogeneous and ongoing cell maturation in the adult mouse spinal cord that changes dynamically on injury},
author = {Albors, Aida Rodrigo, et al.},
url = {https://pubmed.ncbi.nlm.nih.gov/36706756/},
doi = {https://doi.org/10.1016/j.devcel.2023.01.003},
year = {2023},
date = {2023-01-01},
abstract = {The adult spinal cord stem cell potential resides within the ependymal cell population and declines with age. Ependymal cells are, however, heterogeneous, and the biological diversity this represents and how it changes with age remain unknown. Here, we present a single-cell transcriptomic census of spinal cord ependymal cells from adult and aged mice, identifying not only all known ependymal cell subtypes but also immature as well as mature cell states. By comparing transcriptomes of spinal cord and brain ependymal cells, which lack stem cell abilities, we identify immature cells as potential spinal cord stem cells. Following spinal cord injury, these cells re-enter the cell cycle, which is accompanied by a short-lived reversal of ependymal cell maturation. We further analyze ependymal cells in the human spinal cord and identify widespread cell maturation and altered cell identities. This in-depth characterization of spinal cord ependymal cells provides insight into their biology and informs strategies for spinal cord repair.},
keywords = {TEMPEST},
pubstate = {published},
tppubtype = {article}
}
The adult spinal cord stem cell potential resides within the ependymal cell population and declines with age. Ependymal cells are, however, heterogeneous, and the biological diversity this represents and how it changes with age remain unknown. Here, we present a single-cell transcriptomic census of spinal cord ependymal cells from adult and aged mice, identifying not only all known ependymal cell subtypes but also immature as well as mature cell states. By comparing transcriptomes of spinal cord and brain ependymal cells, which lack stem cell abilities, we identify immature cells as potential spinal cord stem cells. Following spinal cord injury, these cells re-enter the cell cycle, which is accompanied by a short-lived reversal of ependymal cell maturation. We further analyze ependymal cells in the human spinal cord and identify widespread cell maturation and altered cell identities. This in-depth characterization of spinal cord ependymal cells provides insight into their biology and informs strategies for spinal cord repair. |
BacterAI maps microbial metabolism without prior knowledge Dama, Adam C. In: 2023. @article{noKey,
title = {BacterAI maps microbial metabolism without prior knowledge},
author = {Dama, Adam C.},
url = {https://www.nature.com/articles/s41564-023-01376-0},
doi = {https://doi.org/10.1038/s41564-023-01376-0},
year = {2023},
date = {2023-01-01},
abstract = {Training artificial intelligence (AI) systems to perform autonomous experiments would vastly increase the throughput of microbiology; however, few microbes have large enough datasets for training such a system. In the present study, we introduce BacterAI, an automated science platform that maps microbial metabolism but requires no prior knowledge. BacterAI learns by converting scientific questions into simple games that it plays with laboratory robots. The agent then distils its findings into logical rules that can be interpreted by human scientists. We use BacterAI to learn the amino acid requirements for two oral streptococci: Streptococcus gordonii and Streptococcus sanguinis. We then show how transfer learning can accelerate BacterAI when investigating new environments or larger media with up to 39 ingredients. Scientific gameplay and BacterAI enable the unbiased, autonomous study of organisms for which no training data exist.},
keywords = {TEMPEST},
pubstate = {published},
tppubtype = {article}
}
Training artificial intelligence (AI) systems to perform autonomous experiments would vastly increase the throughput of microbiology; however, few microbes have large enough datasets for training such a system. In the present study, we introduce BacterAI, an automated science platform that maps microbial metabolism but requires no prior knowledge. BacterAI learns by converting scientific questions into simple games that it plays with laboratory robots. The agent then distils its findings into logical rules that can be interpreted by human scientists. We use BacterAI to learn the amino acid requirements for two oral streptococci: Streptococcus gordonii and Streptococcus sanguinis. We then show how transfer learning can accelerate BacterAI when investigating new environments or larger media with up to 39 ingredients. Scientific gameplay and BacterAI enable the unbiased, autonomous study of organisms for which no training data exist. |
iTAG an optimized IMiD-induced degron for targeted protein degradation in human and murine cells Bouguenina, Habib In: 2023. @article{noKey,
title = {iTAG an optimized IMiD-induced degron for targeted protein degradation in human and murine cells},
author = {Bouguenina, Habib},
url = {https://www.cell.com/iscience/fulltext/S2589-0042(23)01136-7?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004223011367%3Fshowall%3Dtrue},
doi = {https://doi.org/10.1016/j.isci.2023.107059},
year = {2023},
date = {2023-01-01},
abstract = {To address the limitation associated with degron based systems, we have developed iTAG, a synthetic tag based on IMiDs/CELMoDs mechanism of action that improves and addresses the limitations of both PROTAC and previous IMiDs/CeLMoDs based tags. Using structural and sequence analysis, we systematically explored native and chimeric degron containing domains (DCDs) and evaluated their ability to induce degradation. We identified the optimal chimeric iTAG(DCD23 60aa) that elicits robust degradation of targets across cell types and subcellular localizations without exhibiting the well documented “hook effect” of PROTAC-based systems. We showed that iTAG can also induce target degradation by murine CRBN and enabled the exploration of natural neo-substrates that can be degraded by murine CRBN. Hence, the iTAG system constitutes a versatile tool to degrade targets across the human and murine proteome.},
keywords = {TEMPEST},
pubstate = {published},
tppubtype = {article}
}
To address the limitation associated with degron based systems, we have developed iTAG, a synthetic tag based on IMiDs/CELMoDs mechanism of action that improves and addresses the limitations of both PROTAC and previous IMiDs/CeLMoDs based tags. Using structural and sequence analysis, we systematically explored native and chimeric degron containing domains (DCDs) and evaluated their ability to induce degradation. We identified the optimal chimeric iTAG(DCD23 60aa) that elicits robust degradation of targets across cell types and subcellular localizations without exhibiting the well documented “hook effect” of PROTAC-based systems. We showed that iTAG can also induce target degradation by murine CRBN and enabled the exploration of natural neo-substrates that can be degraded by murine CRBN. Hence, the iTAG system constitutes a versatile tool to degrade targets across the human and murine proteome. |
Screening for variable drug responses using human iPSC cohorts Platani, Melpomeni In: 2023. @article{noKey,
title = {Screening for variable drug responses using human iPSC cohorts},
author = {Platani, Melpomeni},
url = {https://www.biorxiv.org/content/10.1101/2023.06.16.545161v1.full},
doi = {https://doi.org/10.1101/2023.06.16.545161},
year = {2023},
date = {2023-01-01},
abstract = {We have used a cohort of human induced pluripotent stem cell (hiPSC) lines to develop a laboratory-based drug screening platform to predict variable drug responses of potential clinical relevance. Our approach is based on the findings that hiPSC lines reflect the genetic identity of the donor and that pluripotent hiPSC lines express a broad repertoire of gene transcripts and proteins. We demonstrate that a cohort of hiPSC lines from different donors can be screened efficiently in their pluripotent state using high-throughput cell painting assays, allowing detection of variable phenotypic responses to a wide range of clinically approved drugs, across multiple disease areas. Furthermore, we provide information on mechanisms of drug-cell interactions underlying the observed variable responses by using quantitative proteomic analysis to compare sets of hiPSC lines that had been stratified objectively using cell painting data. We propose that information derived from comparative drug screening using curated libraries of hiPSC lines can help to increase the success rate of drug development pipelines and improve the delivery of safe new drugs suitable for a broader ethnic and gender diversity within human populations.},
keywords = {TEMPEST},
pubstate = {published},
tppubtype = {article}
}
We have used a cohort of human induced pluripotent stem cell (hiPSC) lines to develop a laboratory-based drug screening platform to predict variable drug responses of potential clinical relevance. Our approach is based on the findings that hiPSC lines reflect the genetic identity of the donor and that pluripotent hiPSC lines express a broad repertoire of gene transcripts and proteins. We demonstrate that a cohort of hiPSC lines from different donors can be screened efficiently in their pluripotent state using high-throughput cell painting assays, allowing detection of variable phenotypic responses to a wide range of clinically approved drugs, across multiple disease areas. Furthermore, we provide information on mechanisms of drug-cell interactions underlying the observed variable responses by using quantitative proteomic analysis to compare sets of hiPSC lines that had been stratified objectively using cell painting data. We propose that information derived from comparative drug screening using curated libraries of hiPSC lines can help to increase the success rate of drug development pipelines and improve the delivery of safe new drugs suitable for a broader ethnic and gender diversity within human populations. |
scONE-seq: A single-cell multi-omics method enables simultaneous dissection of phenotype and genotype heterogeneity from frozen tumors Yu, Lei In: 2023. @article{noKey,
title = {scONE-seq: A single-cell multi-omics method enables simultaneous dissection of phenotype and genotype heterogeneity from frozen tumors},
author = {Yu, Lei},
url = {https://www.science.org/doi/full/10.1126/sciadv.abp8901},
doi = {https://doi.org/10.1126/sciadv.abp8901},
year = {2023},
date = {2023-01-01},
abstract = {Single-cell multi-omics can provide a unique perspective on tumor cellular heterogeneity. Most previous single-cell whole-genome RNA sequencing (scWGS-RNA-seq) methods demonstrate utility with intact cells from fresh samples. Among them, many are not applicable to frozen samples that cannot produce intact single-cell suspensions. We have developed scONE-seq, a versatile scWGS-RNA-seq method that amplifies single-cell DNA and RNA without separating them from each other and hence is compatible with frozen biobanked samples. We benchmarked scONE-seq against existing methods using fresh and frozen samples to demonstrate its performance in various aspects. We identified a unique transcriptionally normal-like tumor clone by analyzing a 2-year frozen astrocytoma sample, demonstrating that performing single-cell multi-omics interrogation on biobanked tissue by scONE-seq could enable previously unidentified discoveries in tumor biology.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Single-cell multi-omics can provide a unique perspective on tumor cellular heterogeneity. Most previous single-cell whole-genome RNA sequencing (scWGS-RNA-seq) methods demonstrate utility with intact cells from fresh samples. Among them, many are not applicable to frozen samples that cannot produce intact single-cell suspensions. We have developed scONE-seq, a versatile scWGS-RNA-seq method that amplifies single-cell DNA and RNA without separating them from each other and hence is compatible with frozen biobanked samples. We benchmarked scONE-seq against existing methods using fresh and frozen samples to demonstrate its performance in various aspects. We identified a unique transcriptionally normal-like tumor clone by analyzing a 2-year frozen astrocytoma sample, demonstrating that performing single-cell multi-omics interrogation on biobanked tissue by scONE-seq could enable previously unidentified discoveries in tumor biology. |
Single-cell transcriptomics unveils xylem cell development and evolution Chia-Chun, Tung et, al. In: 2023. @article{noKey,
title = {Single-cell transcriptomics unveils xylem cell development and evolution},
author = {Chia-Chun, Tung et, al.},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9830878/},
doi = {https://doi.org/10.1186/s13059-022-02845-1},
year = {2023},
date = {2023-01-01},
abstract = {Background
Xylem, the most abundant tissue on Earth, is responsible for lateral growth in plants. Typical xylem has a radial system composed of ray parenchyma cells and an axial system of fusiform cells. In most angiosperms, fusiform cells comprise vessel elements for water transportation and libriform fibers for mechanical support, while both functions are performed by tracheids in other vascular plants such as gymnosperms. Little is known about the developmental programs and evolutionary relationships of these xylem cell types.
Results
Through both single-cell and laser capture microdissection transcriptomic profiling, we determine the developmental lineages of ray and fusiform cells in stem-differentiating xylem across four divergent woody angiosperms. Based on cross-species analyses of single-cell clusters and overlapping trajectories, we reveal highly conserved ray, yet variable fusiform, lineages across angiosperms. Core eudicots Populus trichocarpa and Eucalyptus grandis share nearly identical fusiform lineages, whereas the more basal angiosperm Liriodendron chinense has a fusiform lineage distinct from that in core eudicots. The tracheids in the basal eudicot Trochodendron aralioides, an evolutionarily reversed trait, exhibit strong transcriptomic similarity to vessel elements rather than libriform fibers.
Conclusions
This evo-devo framework provides a comprehensive understanding of the formation of xylem cell lineages across multiple plant species spanning over a hundred million years of evolutionary history.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Background
Xylem, the most abundant tissue on Earth, is responsible for lateral growth in plants. Typical xylem has a radial system composed of ray parenchyma cells and an axial system of fusiform cells. In most angiosperms, fusiform cells comprise vessel elements for water transportation and libriform fibers for mechanical support, while both functions are performed by tracheids in other vascular plants such as gymnosperms. Little is known about the developmental programs and evolutionary relationships of these xylem cell types.
Results
Through both single-cell and laser capture microdissection transcriptomic profiling, we determine the developmental lineages of ray and fusiform cells in stem-differentiating xylem across four divergent woody angiosperms. Based on cross-species analyses of single-cell clusters and overlapping trajectories, we reveal highly conserved ray, yet variable fusiform, lineages across angiosperms. Core eudicots Populus trichocarpa and Eucalyptus grandis share nearly identical fusiform lineages, whereas the more basal angiosperm Liriodendron chinense has a fusiform lineage distinct from that in core eudicots. The tracheids in the basal eudicot Trochodendron aralioides, an evolutionarily reversed trait, exhibit strong transcriptomic similarity to vessel elements rather than libriform fibers.
Conclusions
This evo-devo framework provides a comprehensive understanding of the formation of xylem cell lineages across multiple plant species spanning over a hundred million years of evolutionary history. |
Alkaline-SDS cell lysis of microbes with acetone protein precipitation for proteomic sample preparation in 96-well plate format Chen, Yan, et al. In: 2023. @article{noKey,
title = {Alkaline-SDS cell lysis of microbes with acetone protein precipitation for proteomic sample preparation in 96-well plate format},
author = {Chen, Yan, et al.},
url = {https://www.protocols.io/view/alkaline-sds-cell-lysis-of-microbes-with-acetone-p-b2raqd2e.html},
doi = {dx.doi.org/10.17504/protocols.io.6qpvr6xjpvmk/v1},
year = {2023},
date = {2023-01-01},
abstract = {This high-throughput protocol details the steps to extract protein from Gram-negative bacteria, Gram-positive bacteria, or non-filamentous fungi in 96-well plate format for quantitative proteomic workflows. This protocol uses a bench-top automated liquid dispenser but the volumes and times also apply to manual and multi-channel pipetter use. This protocol is designed for lab-based, culture conditions and synthetic community experiments where complex sample matrices are minimized. Additional sample preservation and/or protein extraction methods may be required for environmental samples (e.g., feces, soil) to minimize protein degradation and maintain sample integrity.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
This high-throughput protocol details the steps to extract protein from Gram-negative bacteria, Gram-positive bacteria, or non-filamentous fungi in 96-well plate format for quantitative proteomic workflows. This protocol uses a bench-top automated liquid dispenser but the volumes and times also apply to manual and multi-channel pipetter use. This protocol is designed for lab-based, culture conditions and synthetic community experiments where complex sample matrices are minimized. Additional sample preservation and/or protein extraction methods may be required for environmental samples (e.g., feces, soil) to minimize protein degradation and maintain sample integrity. |
Insufficient Evidence of a Breastmilk Microbiota at Six-Weeks Postpartum: A Pilot Study Leech, Sophie Meghan, et al. In: 2023. @article{noKey,
title = {Insufficient Evidence of a Breastmilk Microbiota at Six-Weeks Postpartum: A Pilot Study},
author = {Leech, Sophie Meghan, et al.},
url = {https://www.mdpi.com/2072-6643/15/3/696},
doi = {https://doi.org/10.3390/nu15030696},
year = {2023},
date = {2023-01-01},
abstract = {Breastmilk is thought to influence the infant gut by supplying prebiotics in the form of human milk oligosaccharides and potentially seeding the gut with breastmilk microbes. However, the presence of a breastmilk microbiota and origins of these microbes are still debated. As a pilot study, we assessed the microbes present in expressed breastmilk at six-weeks postpartum using shotgun metagenomic sequencing in a heterogenous cohort of women who delivered by vaginal (n = 8) and caesarean delivery (n = 8). In addition, we estimated the microbial load of breastmilk at six-weeks post-partum with quantitative PCR targeting the 16S rRNA gene. Breastmilk at six-weeks postpartum had a low microbial mass, comparable with PCR no-template and extraction controls. Microbes identified through metagenomic sequencing were largely consistent with skin and oral microbes, with four samples returning no identifiable bacterial sequences. Our results do not provide convincing evidence for the existence of a breastmilk microbiota at six-weeks postpartum. It is more likely that microbes present in breastmilk are sourced by ejection from the infant’s mouth and from surrounding skin, as well as contamination during sampling and processing.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Breastmilk is thought to influence the infant gut by supplying prebiotics in the form of human milk oligosaccharides and potentially seeding the gut with breastmilk microbes. However, the presence of a breastmilk microbiota and origins of these microbes are still debated. As a pilot study, we assessed the microbes present in expressed breastmilk at six-weeks postpartum using shotgun metagenomic sequencing in a heterogenous cohort of women who delivered by vaginal (n = 8) and caesarean delivery (n = 8). In addition, we estimated the microbial load of breastmilk at six-weeks post-partum with quantitative PCR targeting the 16S rRNA gene. Breastmilk at six-weeks postpartum had a low microbial mass, comparable with PCR no-template and extraction controls. Microbes identified through metagenomic sequencing were largely consistent with skin and oral microbes, with four samples returning no identifiable bacterial sequences. Our results do not provide convincing evidence for the existence of a breastmilk microbiota at six-weeks postpartum. It is more likely that microbes present in breastmilk are sourced by ejection from the infant’s mouth and from surrounding skin, as well as contamination during sampling and processing. |
High-Throughput Exonuclease Assay Based on the Fluorescent Base Analogue 2-Aminopurine Botto, Margherita M. In: 2023. @article{noKey,
title = {High-Throughput Exonuclease Assay Based on the Fluorescent Base Analogue 2-Aminopurine},
author = {Botto, Margherita M.},
url = {https://pubs.acs.org/doi/full/10.1021/acsomega.2c06577},
doi = {https://doi.org/10.1021/acsomega.2c06577},
year = {2023},
date = {2023-01-01},
abstract = {Exonucleases are essential enzymes that remove nucleotides from free DNA ends during DNA replication, DNA repair, and telomere maintenance. Due to their essential role, they are potential targets for novel anticancer and antimicrobial drugs but have so far been little exploited. Here, we present a simple and versatile real-time exonuclease assay based on 2-aminopurine, an intrinsically fluorescent nucleotide that is quenched by neighboring bases when embedded in DNA. We show that our assay is applicable to different eukaryotic and bacterial exonucleases acting on both 3′ and 5′ DNA ends over a wide range of protein activities and suitable for a high-throughput inhibitor screening campaign. Using our assay, we discover a novel inhibitor of the Mycobacterium tuberculosis PHP-exonuclease that is part of the replicative DNA polymerase DnaE1. Hence, our novel assay will be a useful tool for high-throughput screening for novel exonuclease inhibitors that may interfere with DNA replication or DNA maintenance.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Exonucleases are essential enzymes that remove nucleotides from free DNA ends during DNA replication, DNA repair, and telomere maintenance. Due to their essential role, they are potential targets for novel anticancer and antimicrobial drugs but have so far been little exploited. Here, we present a simple and versatile real-time exonuclease assay based on 2-aminopurine, an intrinsically fluorescent nucleotide that is quenched by neighboring bases when embedded in DNA. We show that our assay is applicable to different eukaryotic and bacterial exonucleases acting on both 3′ and 5′ DNA ends over a wide range of protein activities and suitable for a high-throughput inhibitor screening campaign. Using our assay, we discover a novel inhibitor of the Mycobacterium tuberculosis PHP-exonuclease that is part of the replicative DNA polymerase DnaE1. Hence, our novel assay will be a useful tool for high-throughput screening for novel exonuclease inhibitors that may interfere with DNA replication or DNA maintenance. |
High-throughput microbial culturomics using automation and machine learning Huang, Yiming In: 2023. @article{noKey,
title = {High-throughput microbial culturomics using automation and machine learning},
author = {Huang, Yiming},
url = {https://www.nature.com/articles/s41587-023-01674-2},
doi = {https://doi.org/10.1038/s41587-023-01674-2},
year = {2023},
date = {2023-01-01},
abstract = {Pure bacterial cultures remain essential for detailed experimental and mechanistic studies in microbiome research, and traditional methods to isolate individual bacteria from complex microbial ecosystems are labor-intensive, difficult-to-scale and lack phenotype–genotype integration. Here we describe an open-source high-throughput robotic strain isolation platform for the rapid generation of isolates on demand. We develop a machine learning approach that leverages colony morphology and genomic data to maximize the diversity of microbes isolated and enable targeted picking of specific genera. Application of this platform on fecal samples from 20 humans yields personalized gut microbiome biobanks totaling 26,997 isolates that represented >80% of all abundant taxa. Spatial analysis on >100,000 visually captured colonies reveals cogrowth patterns between Ruminococcaceae, Bacteroidaceae, Coriobacteriaceae and Bifidobacteriaceae families that suggest important microbial interactions. Comparative analysis of 1,197 high-quality genomes from these biobanks shows interesting intra- and interpersonal strain evolution, selection and horizontal gene transfer. This culturomics framework should empower new research efforts to systematize the collection and quantitative analysis of imaging-based phenotypes with high-resolution genomics data for many emerging microbiome studies.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Pure bacterial cultures remain essential for detailed experimental and mechanistic studies in microbiome research, and traditional methods to isolate individual bacteria from complex microbial ecosystems are labor-intensive, difficult-to-scale and lack phenotype–genotype integration. Here we describe an open-source high-throughput robotic strain isolation platform for the rapid generation of isolates on demand. We develop a machine learning approach that leverages colony morphology and genomic data to maximize the diversity of microbes isolated and enable targeted picking of specific genera. Application of this platform on fecal samples from 20 humans yields personalized gut microbiome biobanks totaling 26,997 isolates that represented >80% of all abundant taxa. Spatial analysis on >100,000 visually captured colonies reveals cogrowth patterns between Ruminococcaceae, Bacteroidaceae, Coriobacteriaceae and Bifidobacteriaceae families that suggest important microbial interactions. Comparative analysis of 1,197 high-quality genomes from these biobanks shows interesting intra- and interpersonal strain evolution, selection and horizontal gene transfer. This culturomics framework should empower new research efforts to systematize the collection and quantitative analysis of imaging-based phenotypes with high-resolution genomics data for many emerging microbiome studies. |
Initial recommendations for performing, benchmarking and reporting single-cell proteomics experiments Gatto, Laurent In: 2023. @article{noKey,
title = {Initial recommendations for performing, benchmarking and reporting single-cell proteomics experiments},
author = {Gatto, Laurent},
url = {https://www.nature.com/articles/s41592-023-01785-3#Ack1},
doi = {https://doi.org/10.1038/s41592-023-01785-3},
year = {2023},
date = {2023-01-01},
abstract = {Analyzing proteins from single cells by tandem mass spectrometry (MS) has recently become technically feasible. While such analysis has the potential to accurately quantify thousands of proteins across thousands of single cells, the accuracy and reproducibility of the results may be undermined by numerous factors affecting experimental design, sample preparation, data acquisition and data analysis. We expect that broadly accepted community guidelines and standardized metrics will enhance rigor, data quality and alignment between laboratories. Here we propose best practices, quality controls and data-reporting recommendations to assist in the broad adoption of reliable quantitative workflows for single-cell proteomics.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Analyzing proteins from single cells by tandem mass spectrometry (MS) has recently become technically feasible. While such analysis has the potential to accurately quantify thousands of proteins across thousands of single cells, the accuracy and reproducibility of the results may be undermined by numerous factors affecting experimental design, sample preparation, data acquisition and data analysis. We expect that broadly accepted community guidelines and standardized metrics will enhance rigor, data quality and alignment between laboratories. Here we propose best practices, quality controls and data-reporting recommendations to assist in the broad adoption of reliable quantitative workflows for single-cell proteomics. |
Discovery of DTX3L inhibitors through a homogeneous FRET-based assay that monitors formation and removal of poly-ubiquitin chains Vela-Rodríguez, Carlos In: 2023. @article{noKey,
title = {Discovery of DTX3L inhibitors through a homogeneous FRET-based assay that monitors formation and removal of poly-ubiquitin chains},
author = {Vela-Rodríguez, Carlos},
url = {https://www.biorxiv.org/content/10.1101/2023.03.13.532453v1.article-info},
doi = {https://doi.org/10.1101/2023.03.13.532453},
year = {2023},
date = {2023-01-01},
abstract = {Ubiquitination is a complex and reversible protein post-translational modification in which the subsequent action of enzymes belonging to three different families, broadly referred to as E1, E2 and E3, results in the covalent linking of ubiquitin to a target protein. While this linkage is canonically an isopeptide bond between the C-terminus of ubiquitin and the lysine residue of the target protein, Ser, Thr, and Tyr can also be susceptible to ubiquitination through an oxyester bond. Once ubiquitinated, multiple units of ubiquitin can be attached to the initial ubiquitin thus extending it to a chain of ubiquitins. Ubiquitination regulates multiple cellular processes, but it is best known as a modification that targets proteins for proteasomal degradation following the formation poly-ubiquitin chains linked through lysine 48 or 63 of ubiquitin. Dysregulation of ubiquitination has been associated with multiple types of cancer and efforts have been carried out to develop technologies that lead to the identification of inhibitors of the enzymes involved in the ubiquitination cascade. Herein, we present the development of a FRET-based assay that allows us to monitor auto-ubiquitination of DTX3L, a RING-type E3 ubiquitin ligase. Our method shows a robust signal window with a robust average Z’ factor of 0.76. From a validatory screening experiment we have identified the first molecules that inhibit DTX3L with potencies in the low micromolar range. Additionally, we have expanded the system to study deubiquitinases such as USP28 that lead to reduction of FRET due to hydrolysis of fluorescent poly-Ub chains.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Ubiquitination is a complex and reversible protein post-translational modification in which the subsequent action of enzymes belonging to three different families, broadly referred to as E1, E2 and E3, results in the covalent linking of ubiquitin to a target protein. While this linkage is canonically an isopeptide bond between the C-terminus of ubiquitin and the lysine residue of the target protein, Ser, Thr, and Tyr can also be susceptible to ubiquitination through an oxyester bond. Once ubiquitinated, multiple units of ubiquitin can be attached to the initial ubiquitin thus extending it to a chain of ubiquitins. Ubiquitination regulates multiple cellular processes, but it is best known as a modification that targets proteins for proteasomal degradation following the formation poly-ubiquitin chains linked through lysine 48 or 63 of ubiquitin. Dysregulation of ubiquitination has been associated with multiple types of cancer and efforts have been carried out to develop technologies that lead to the identification of inhibitors of the enzymes involved in the ubiquitination cascade. Herein, we present the development of a FRET-based assay that allows us to monitor auto-ubiquitination of DTX3L, a RING-type E3 ubiquitin ligase. Our method shows a robust signal window with a robust average Z’ factor of 0.76. From a validatory screening experiment we have identified the first molecules that inhibit DTX3L with potencies in the low micromolar range. Additionally, we have expanded the system to study deubiquitinases such as USP28 that lead to reduction of FRET due to hydrolysis of fluorescent poly-Ub chains. |
Purification and characterization of human neural stem and progenitor cells Liu, Daniel Dan In: 2023. @article{noKey,
title = {Purification and characterization of human neural stem and progenitor cells},
author = {Liu, Daniel Dan},
url = {https://www.cell.com/cell/fulltext/S0092-8674(23)00160-5?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867423001605%3Fshowall%3Dtrue},
doi = {https://doi.org/10.1016/j.cell.2023.02.017},
year = {2023},
date = {2023-01-01},
abstract = {The human brain undergoes rapid development at mid-gestation from a pool of neural stem and progenitor cells (NSPCs) that give rise to the neurons, oligodendrocytes, and astrocytes of the mature brain. Functional study of these cell types has been hampered by a lack of precise purification methods. We describe a method for prospectively isolating ten distinct NSPC types from the developing human brain using cell-surface markers. CD24−THY1−/lo cells were enriched for radial glia, which robustly engrafted and differentiated into all three neural lineages in the mouse brain. THY1hi cells marked unipotent oligodendrocyte precursors committed to an oligodendroglial fate, and CD24+THY1−/lo cells marked committed excitatory and inhibitory neuronal lineages. Notably, we identify and functionally characterize a transcriptomically distinct THY1hiEGFRhiPDGFRA− bipotent glial progenitor cell (GPC), which is lineage-restricted to astrocytes and oligodendrocytes, but not to neurons. Our study provides a framework for the functional study of distinct cell types in human neurodevelopment.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
The human brain undergoes rapid development at mid-gestation from a pool of neural stem and progenitor cells (NSPCs) that give rise to the neurons, oligodendrocytes, and astrocytes of the mature brain. Functional study of these cell types has been hampered by a lack of precise purification methods. We describe a method for prospectively isolating ten distinct NSPC types from the developing human brain using cell-surface markers. CD24−THY1−/lo cells were enriched for radial glia, which robustly engrafted and differentiated into all three neural lineages in the mouse brain. THY1hi cells marked unipotent oligodendrocyte precursors committed to an oligodendroglial fate, and CD24+THY1−/lo cells marked committed excitatory and inhibitory neuronal lineages. Notably, we identify and functionally characterize a transcriptomically distinct THY1hiEGFRhiPDGFRA− bipotent glial progenitor cell (GPC), which is lineage-restricted to astrocytes and oligodendrocytes, but not to neurons. Our study provides a framework for the functional study of distinct cell types in human neurodevelopment. |
A novel fluorogenic reporter substrate for 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-2 (PLCγ2): Application to high-throughput screening for activators to treat Alzheimer's disease Visvanathan, Ramya In: 2023. @article{noKey,
title = {A novel fluorogenic reporter substrate for 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-2 (PLCγ2): Application to high-throughput screening for activators to treat Alzheimer's disease},
author = {Visvanathan, Ramya},
url = {https://slas-discovery.org/article/S2472-5552(23)00024-2/fulltext},
doi = {https://doi.org/10.1016/j.slasd.2023.03.003},
year = {2023},
date = {2023-01-01},
abstract = {A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease (LOAD) and therefore, activation of wild-type PLCγ2 has been suggested as a potential therapeutic target for the prevention and treatment of LOAD. Additionally, PLCγ2 has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLCγ2 activity have been identified. Here, pharmacological inhibition may provide a therapeutic effect. In order to facilitate our investigation of the activity of PLCγ2, we developed an optimized fluorogenic substrate to monitor enzymatic activity in aqueous solution. This was accomplished by first exploring the spectral properties of various “turn-on” fluorophores. The most promising turn-on fluorophore was incorporated into a water-soluble PLCγ2 reporter substrate, which we named C8CF3-coumarin. The ability of PLCγ2 to enzymatically process C8CF3-coumarin was confirmed, and the kinetics of the reaction were determined. Reaction conditions were optimized to identify small molecule activators, and a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) was performed with the goal of identifying small molecule activators of PLCγ2. The optimized screening conditions allowed identification of potential PLCγ2 activators and inhibitors, thus demonstrating the feasibility of this approach for high-throughput screening.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease (LOAD) and therefore, activation of wild-type PLCγ2 has been suggested as a potential therapeutic target for the prevention and treatment of LOAD. Additionally, PLCγ2 has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLCγ2 activity have been identified. Here, pharmacological inhibition may provide a therapeutic effect. In order to facilitate our investigation of the activity of PLCγ2, we developed an optimized fluorogenic substrate to monitor enzymatic activity in aqueous solution. This was accomplished by first exploring the spectral properties of various “turn-on” fluorophores. The most promising turn-on fluorophore was incorporated into a water-soluble PLCγ2 reporter substrate, which we named C8CF3-coumarin. The ability of PLCγ2 to enzymatically process C8CF3-coumarin was confirmed, and the kinetics of the reaction were determined. Reaction conditions were optimized to identify small molecule activators, and a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) was performed with the goal of identifying small molecule activators of PLCγ2. The optimized screening conditions allowed identification of potential PLCγ2 activators and inhibitors, thus demonstrating the feasibility of this approach for high-throughput screening. |
Core species and interactions prominent in fish-associated microbiome dynamics Yajima, Daii In: 2023. @article{noKey,
title = {Core species and interactions prominent in fish-associated microbiome dynamics},
author = {Yajima, Daii},
url = {https://link.springer.com/article/10.1186/s40168-023-01498-x},
doi = {https://doi.org/10.1186/s40168-023-01498-x},
year = {2023},
date = {2023-01-01},
abstract = {Background
In aquatic ecosystems, the health and performance of fish depend greatly on the dynamics of microbial community structure in the background environment. Nonetheless, finding microbes with profound impacts on fish’s performance out of thousands of candidate species remains a major challenge.
Methods
We examined whether time-series analyses of microbial population dynamics could illuminate core components and structure of fish-associated microbiomes in the background (environmental) water. By targeting eel-aquaculture-tank microbiomes as model systems, we reconstructed the population dynamics of the 9605 bacterial and 303 archaeal species/strains across 128 days.
Results
Due to the remarkable increase/decrease of constituent microbial population densities, the taxonomic compositions of the microbiome changed drastically through time. We then found that some specific microbial taxa showed a positive relationship with eels’ activity levels even after excluding confounding effects of environmental parameters (pH and dissolved oxygen level) on population dynamics. In particular, a vitamin-B12-producing bacteria, Cetobacterium somerae, consistently showed strong positive associations with eels’ activity levels across the replicate time series of the five aquaculture tanks analyzed. Network theoretical and metabolic modeling analyses further suggested that the highlighted bacterium and some other closely-associated bacteria formed “core microbiomes” with potentially positive impacts on eels.
Conclusions
Overall, these results suggest that the integration of microbiology, ecological theory, and network science allows us to explore core species and interactions embedded within complex dynamics of fish-associated microbiomes.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Background
In aquatic ecosystems, the health and performance of fish depend greatly on the dynamics of microbial community structure in the background environment. Nonetheless, finding microbes with profound impacts on fish’s performance out of thousands of candidate species remains a major challenge.
Methods
We examined whether time-series analyses of microbial population dynamics could illuminate core components and structure of fish-associated microbiomes in the background (environmental) water. By targeting eel-aquaculture-tank microbiomes as model systems, we reconstructed the population dynamics of the 9605 bacterial and 303 archaeal species/strains across 128 days.
Results
Due to the remarkable increase/decrease of constituent microbial population densities, the taxonomic compositions of the microbiome changed drastically through time. We then found that some specific microbial taxa showed a positive relationship with eels’ activity levels even after excluding confounding effects of environmental parameters (pH and dissolved oxygen level) on population dynamics. In particular, a vitamin-B12-producing bacteria, Cetobacterium somerae, consistently showed strong positive associations with eels’ activity levels across the replicate time series of the five aquaculture tanks analyzed. Network theoretical and metabolic modeling analyses further suggested that the highlighted bacterium and some other closely-associated bacteria formed “core microbiomes” with potentially positive impacts on eels.
Conclusions
Overall, these results suggest that the integration of microbiology, ecological theory, and network science allows us to explore core species and interactions embedded within complex dynamics of fish-associated microbiomes. |
Spatial and single-cell transcriptomics reveal neuron-astrocyte interplay in long-term memory Sun, Wenfei In: 2023. @article{noKey,
title = {Spatial and single-cell transcriptomics reveal neuron-astrocyte interplay in long-term memory},
author = {Sun, Wenfei},
url = {https://www.biorxiv.org/content/10.1101/2023.03.20.533566v1.full},
doi = {https://doi.org/10.1101/2023.03.20.533566},
year = {2023},
date = {2023-01-01},
abstract = {Memory encodes past experiences, thereby enabling future plans. The basolateral amygdala (BLA) is a center of salience networks that underlie emotional experience and thus plays a key role in long-term fear memory formation1, 2. Here we used spatial and single-cell transcriptomics to illuminate the cellular and molecular architecture of the role of the basolateral amygdala in long-term memory. We identified transcriptional signatures in subpopulations of neurons and astrocytes that were memory-specific and persisted for weeks. These transcriptional signatures implicate neuropeptide signaling, mitogen-activated protein kinase (MAPK), brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), ubiquitination pathways, and synaptic connectivity in long-term memory. We also discovered that a neuronal sub-population, defined by increased Penk expression and decreased Tac expression, constitutes the most prominent component of the BLA’s memory engram. These transcriptional changes were observed both with single-cell RNAseq and with single-molecule spatial transcriptomics in intact slices, thereby providing a rich spatial map of a memory engram. The spatial data enabled us to show that this neuronal subpopulation further interacts with spatially related astrocytes that are essential for memory consolidation, indicating that neurons require interactions with astrocytes to encode long term memory.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Memory encodes past experiences, thereby enabling future plans. The basolateral amygdala (BLA) is a center of salience networks that underlie emotional experience and thus plays a key role in long-term fear memory formation1, 2. Here we used spatial and single-cell transcriptomics to illuminate the cellular and molecular architecture of the role of the basolateral amygdala in long-term memory. We identified transcriptional signatures in subpopulations of neurons and astrocytes that were memory-specific and persisted for weeks. These transcriptional signatures implicate neuropeptide signaling, mitogen-activated protein kinase (MAPK), brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), ubiquitination pathways, and synaptic connectivity in long-term memory. We also discovered that a neuronal sub-population, defined by increased Penk expression and decreased Tac expression, constitutes the most prominent component of the BLA’s memory engram. These transcriptional changes were observed both with single-cell RNAseq and with single-molecule spatial transcriptomics in intact slices, thereby providing a rich spatial map of a memory engram. The spatial data enabled us to show that this neuronal subpopulation further interacts with spatially related astrocytes that are essential for memory consolidation, indicating that neurons require interactions with astrocytes to encode long term memory. |
Isolation and characterisation of novel Methanocorpusculum species indicates the genus is ancestrally host-associated Volmer, James G. In: 2023. @article{noKey,
title = {Isolation and characterisation of novel Methanocorpusculum species indicates the genus is ancestrally host-associated},
author = {Volmer, James G.},
url = {https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-023-01524-2},
doi = {https://doi.org/10.1186/s12915-023-01524-2},
year = {2023},
date = {2023-01-01},
abstract = {Background
With an increasing interest in the manipulation of methane produced from livestock cultivation, the microbiome of Australian marsupials provides a unique ecological and evolutionary comparison with ‘low-methane’ emitters. Previously, marsupial species were shown to be enriched for novel lineages of Methanocorpusculum, as well as Methanobrevibacter, Methanosphaera, and Methanomassiliicoccales. Despite sporadic reports of Methanocorpusculum from stool samples of various animal species, there remains little information on the impacts of these methanogens on their hosts.
Results
Here, we characterise novel host-associated species of Methanocorpusculum, to explore unique host-specific genetic factors and their associated metabolic potential. We performed comparative analyses on 176 Methanocorpusculum genomes comprising 130 metagenome-assembled genomes (MAGs) recovered from 20 public animal metagenome datasets and 35 other publicly available Methanocorpusculum MAGs and isolate genomes of host-associated and environmental origin. Nine MAGs were also produced from faecal metagenomes of the common wombat (Vombatus ursinus) and mahogany glider (Petaurus gracilis), along with the cultivation of one axenic isolate from each respective animal; M. vombati (sp. nov.) and M. petauri (sp. nov.).
Conclusions
Through our analyses, we substantially expand the available genetic information for this genus by describing the phenotypic and genetic characteristics of 23 host-associated species of Methanocorpusculum. These lineages display differential enrichment of genes associated with methanogenesis, amino acid biosynthesis, transport system proteins, phosphonate metabolism, and carbohydrate-active enzymes. These results provide insights into the differential genetic and functional adaptations of these novel host-associated species of Methanocorpusculum and suggest that this genus is ancestrally host-associated.},
keywords = {MANTIS},
pubstate = {published},
tppubtype = {article}
}
Background
With an increasing interest in the manipulation of methane produced from livestock cultivation, the microbiome of Australian marsupials provides a unique ecological and evolutionary comparison with ‘low-methane’ emitters. Previously, marsupial species were shown to be enriched for novel lineages of Methanocorpusculum, as well as Methanobrevibacter, Methanosphaera, and Methanomassiliicoccales. Despite sporadic reports of Methanocorpusculum from stool samples of various animal species, there remains little information on the impacts of these methanogens on their hosts.
Results
Here, we characterise novel host-associated species of Methanocorpusculum, to explore unique host-specific genetic factors and their associated metabolic potential. We performed comparative analyses on 176 Methanocorpusculum genomes comprising 130 metagenome-assembled genomes (MAGs) recovered from 20 public animal metagenome datasets and 35 other publicly available Methanocorpusculum MAGs and isolate genomes of host-associated and environmental origin. Nine MAGs were also produced from faecal metagenomes of the common wombat (Vombatus ursinus) and mahogany glider (Petaurus gracilis), along with the cultivation of one axenic isolate from each respective animal; M. vombati (sp. nov.) and M. petauri (sp. nov.).
Conclusions
Through our analyses, we substantially expand the available genetic information for this genus by describing the phenotypic and genetic characteristics of 23 host-associated species of Methanocorpusculum. These lineages display differential enrichment of genes associated with methanogenesis, amino acid biosynthesis, transport system proteins, phosphonate metabolism, and carbohydrate-active enzymes. These results provide insights into the differential genetic and functional adaptations of these novel host-associated species of Methanocorpusculum and suggest that this genus is ancestrally host-associated. |