scholarly journals Independent glial subtypes delay development and extend healthy lifespan upon reduced insulin-PI3K signalling

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Nathaniel S. Woodling ◽  
Arjunan Rajasingam ◽  
Lucy J. Minkley ◽  
Alberto Rizzo ◽  
Linda Partridge
Keyword(s):  
Glial Cell ◽  
Cell Types ◽  
Therapeutic Interventions ◽  
Developmental Timing ◽  
Cell Type ◽  
Specific Effects ◽  
Trade Offs ◽  
Distinct Cell ◽  
Pi3k Signalling ◽  
Cell Type Specific

Abstract Background The increasing age of global populations highlights the urgent need to understand the biological underpinnings of ageing. To this end, inhibition of the insulin/insulin-like signalling (IIS) pathway can extend healthy lifespan in diverse animal species, but with trade-offs including delayed development. It is possible that distinct cell types underlie effects on development and ageing; cell-type-specific strategies could therefore potentially avoid negative trade-offs when targeting diseases of ageing, including prevalent neurodegenerative diseases. The highly conserved diversity of neuronal and non-neuronal (glial) cell types in the Drosophila nervous system makes it an attractive system to address this possibility. We have thus investigated whether IIS in distinct glial cell populations differentially modulates development and lifespan in Drosophila. Results We report here that glia-specific IIS inhibition, using several genetic means, delays development while extending healthy lifespan. The effects on lifespan can be recapitulated by adult-onset IIS inhibition, whereas developmental IIS inhibition is dispensable for modulation of lifespan. Notably, the effects we observe on both lifespan and development act through the PI3K branch of the IIS pathway and are dependent on the transcription factor FOXO. Finally, IIS inhibition in several glial subtypes can delay development without extending lifespan, whereas the same manipulations in astrocyte-like glia alone are sufficient to extend lifespan without altering developmental timing. Conclusions These findings reveal a role for distinct glial subpopulations in the organism-wide modulation of development and lifespan, with IIS in astrocyte-like glia contributing to lifespan modulation but not to developmental timing. Our results enable a more complete picture of the cell-type-specific effects of the IIS network, a pathway whose evolutionary conservation in humans make it tractable for therapeutic interventions. Our findings therefore underscore the necessity for cell-type-specific strategies to optimise interventions for the diseases of ageing.

scholarly journals Oligodendrocytes and Microglia Are Selectively Vulnerable to Combined Hypoxia and Hypoglycemia Injury in Vitro

1998 ◽  
Vol 18 (5) ◽  
pp. 521-530 ◽  
Author(s):  
Susan A. Lyons ◽  
Helmut Kettenmann
Keyword(s):  
Lactate Dehydrogenase ◽  
Glial Cell ◽  
Glial Cells ◽  
Cell Types ◽  
Neonatal Rat ◽  
Radical Scavenger ◽  
Cell Type ◽  
Hypoxic Conditions ◽  
Cell Type Specific

The major classes of glial cells, namely astrocytes, oligodendrocytes, and microglial cells were compared in parallel for their susceptibility to damage after combined hypoxia and hypoglycemia or hypoxia alone. The three glial cell types were isolated from neonatal rat brains, separated, and incubated in N2/CO2-gassed buffer-containing glucose or glucose substitutes, 2-deoxyglucose or mannitol (both nonmetabolizable sugars). The damage to the cells after 6 hours' exposure was determined at 0, 1, 3, 7 days based on release of lactate dehydrogenase and counting of ethidium bromide–stained dead cells, double-stained with cell-type specific markers. When 2-deoxyglucose replaced glucose during 6 hours of hypoxia, both oligodendrocytes and microglia rarely survived (18% and 12%, respectively). Astroglia initially increased the release of lactate dehydrogenase but maintained 98% to 99% viability. When mannitol, a radical scavenger and osmolarity stabilizer, replaced glucose during 6 hours of hypoxia, oligodendrocytes rarely survived (10%), astroglia survival remained at 99%, but microglia survival increased to 50%. After exposure to 6 and 42 hours, respectively, of hypoxic conditions alone, oligodendrocytes exhibited 10% survival whereas microglia and astroglia were only temporarily stressed and subsequently survived. In conclusion, oligodendrocytes, then microglia, are the most vulnerable glial cell types in response to hypoxia or hypoglycemia conditions, whereas astrocytes from the same preparations recover.

scholarly journals Single Cell Gene Expression Analysis in a 3D Microtissue Liver Model Reveals Cell Type-Specific Responses to Pro-Fibrotic TGF-β1 Stimulation

2021 ◽  
Vol 22 (9) ◽  
pp. 4372
Author(s):  
Catherine Jane Messner ◽  
Lmar Babrak ◽  
Gaia Titolo ◽  
Michaela Caj ◽  
Enkelejda Miho ◽  
...  
Keyword(s):  
Single Cell ◽  
Inflammatory Responses ◽  
3D Cell Culture ◽  
Cell Types ◽  
Therapeutic Interventions ◽  
Matrix Remodeling ◽  
Cell Type ◽  
Isolated Cells ◽  
Cell Type Specific ◽  
Tgf Β1

3D cell culture systems are widely used to study disease mechanisms and therapeutic interventions. Multicellular liver microtissues (MTs) comprising HepaRG, hTERT-HSC and THP-1 maintain multicellular interactions and physiological properties required to mimic liver fibrosis. However, the inherent complexity of multicellular 3D-systems often hinders the discrimination of cell type specific responses. Here, we aimed at applying single cell sequencing (scRNA-seq) to discern the molecular responses of cells involved in the development of fibrosis elicited by TGF-β1. To obtain single cell suspensions from the MTs, an enzymatic dissociation method was optimized. Isolated cells showed good viability, could be re-plated and cultured in 2D, and expressed specific markers determined by scRNA-seq, qRT-PCR, ELISA and immunostaining. The three cell populations were successfully clustered using supervised and unsupervised methods based on scRNA-seq data. TGF-β1 led to a fibrotic phenotype in the MTs, detected as decreased albumin and increased αSMA expression. Cell-type specific responses to the treatment were identified for each of the three cell types. They included HepaRG damage characterized by a decrease in cellular metabolism, prototypical inflammatory responses in THP-1s and extracellular matrix remodeling in hTERT-HSCs. Furthermore, we identified novel cell-specific putative fibrosis markers in hTERT-HSC (COL15A1), and THP-1 (ALOX5AP and LAPTM5).

scholarly journals A novel method to identify cell-type specific regulatory variants and their role in cancer risk

2021 ◽  
Author(s):  
Cynthia A Kalita ◽  
Alexander Gusev
Keyword(s):  
Cancer Risk ◽  
Cell Types ◽  
New Method ◽  
Rna Seq ◽  
Cell Type ◽  
Regulatory Variants ◽  
Specific Effects ◽  
Allele Specific ◽  
Cell Type Specific ◽  
Eqtl Data

Background: Expression quantitative trait loci (eQTLs) have been crucial in providing an understanding of how genetic variants influence gene expression. However, eQTLs are known to exert cell type specific effects, and existing methods to identify cell type specific QTLs in bulk data require large sample sizes. Results: Here, we propose DeCAF (DEconvoluted cell type Allele specific Function), a new method to identify cell-fraction (cf) QTLs in tumors by leveraging both allelic and total expression information. Applying DeCAF to RNA-seq data from TCGA, we identified 3,664 genes with cfQTLs (at 10% FDR) in 14 cell types, a 5.63x increase in discovery over conventional interaction-eQTL mapping. cfQTLs replicated in external cell type specific eQTL data and were more enriched for cancer risk than conventional eQTLs. The intersection of tumor-specific QTL effects (tsQTLs) with GWAS loci identified rs4765621 and SCARB1, which has been previously linked to renal cell carcinoma (RCC) progression and experimentally validated in tumors. Conclusions: Our new method, DeCAF, empowers the discovery of biologically meaningful cfQTLs from bulk RNA-seq data in moderately sized studies. Our study contributes to a better understanding of germline mechanisms underlying the anticancer immune response as well as cfQTLs contributing to cancer risk.

scholarly journals Cell-type-specific promoters for C. elegans glia

2020 ◽  
Author(s):  
Wendy Fung ◽  
Leigh Wexler ◽  
Maxwell G. Heiman
Keyword(s):  
Glial Cell ◽  
Internal State ◽  
Cell Types ◽  
Cell Type ◽  
Sequencing Data ◽  
C Elegans ◽  
External Conditions ◽  
Glial Function ◽  
Cell Type Specific ◽  
And Function

ABSTRACTGlia shape the development and function of the C. elegans nervous system, especially its sense organs and central neuropil (nerve ring). Cell-type-specific promoters allow investigators to label or manipulate individual glial cell types, and therefore provide a key tool for deciphering glial function. In this technical resource, we compare the specificity, brightness, and consistency of cell-type-specific promoters for C. elegans glia. We identify a set of promoters for the study of seven glial cell types (F16F9.3, amphid and phasmid sheath glia; F11C7.2, amphid sheath glia only; grl-2, amphid and phasmid socket glia; hlh-17, cephalic (CEP) sheath glia; and grl-18, inner labial (IL) socket glia) as well as a pan-glial promoter (mir-228). We compare these promoters to promoters that are expressed more variably in combinations of glial cell types (delm-1 and itx-1). We note that the expression of some promoters depends on external conditions or the internal state of the organism, such as developmental stage, suggesting glial plasticity. Finally, we demonstrate an approach for prospectively identifying cell-type-specific glial promoters using existing single-cell sequencing data, and we use this approach to identify two novel promoters specific to IL socket glia (col-53 and col-177).

scholarly journals Structure and mechanism of SARS-CoV-2 Spike N679-V687 deletion variant elucidate cell-type specific evolution of viral fitness

2021 ◽  
Author(s):  
Kapil Gupta ◽  
Christine Toelzer ◽  
Maia Kavanagh Williamson ◽  
Deborah Shoemark ◽  
A. Sofia F. Oliveira ◽  
...  
Keyword(s):  
Cell Types ◽  
Viral Fitness ◽  
Cell Tropism ◽  
Cell Type ◽  
Amino Acid Deletion ◽  
Recognition Motif ◽  
Mechanistic Insight ◽  
Distinct Cell ◽  
Cell Type Specific ◽  
Insight Into

As the global burden of SARS-CoV-2 infections escalates, so does the evolution of viral variants which is of particular concern due to their potential for increased transmissibility and pathology. In addition to this entrenched variant diversity in circulation, RNA viruses can also display genetic diversity within single infected hosts with co-existing viral variants evolving differently in distinct cell types. The BriSΔ variant, originally identified as a viral subpopulation by passaging SARS-CoV-2 isolate hCoV-19/England/02/2020, comprises in the spike glycoprotein an eight amino-acid deletion encompassing the furin recognition motif and S1/S2 cleavage site. Here, we analyzed the structure, function and molecular dynamics of this variant spike, providing mechanistic insight into how the deletion correlates to viral cell tropism, ACE2 receptor binding and infectivity, allowing the virus to probe diverse trajectories in distinct cell types to evolve viral fitness.

Characterization and subcellular localization of a bacterial flotillin homologue

Microbiology ◽  
2009 ◽  
Vol 155 (6) ◽  
pp. 1786-1799 ◽  
Author(s):  
Catriona Donovan ◽  
Marc Bramkamp
Keyword(s):  
Early Stage ◽  
Model Organism ◽  
Cell Types ◽  
Specific Gene ◽  
Cell Type ◽  
Distinct Cell ◽  
Sporulation Efficiency ◽  
Cell Type Specific ◽  
Detergent Resistant Membranes

The process of endospore formation in Bacillus subtilis is complex, requiring the generation of two distinct cell types, a forespore and larger mother cell. The development of these cell types is controlled and regulated by cell type-specific gene expression, activated by a σ-factor cascade. Activation of these cell type-specific sigma factors is coupled with the completion of polar septation. Here, we describe a novel protein, YuaG, a eukaryotic reggie/flotillin homologue that is involved in the early stages of sporulation of the Gram-positive model organism B. subtilis. YuaG localizes in discrete foci in the membrane and is highly dynamic. Purification of detergent-resistant membranes revealed that YuaG is associated with negatively charged phospholipids, e.g. phosphatidylglycerol (PG) or cardiolipin (CL). However, localization of YuaG is not always dependent on PG/CL in vivo. A yuaG disruption strain shows a delay in the onset of sporulation along with reduced sporulation efficiency, where the spores develop to a certain stage and then appear to be trapped at this stage. Our results indicate that YuaG is involved in the early stage of spore development, probably playing a role in the signalling cascade at the onset of sporulation.

scholarly journals Cell type-specific modulation of healthspan by Forkhead family transcription factors in the nervous system

2021 ◽  
Vol 118 (8) ◽  
pp. e2011491118 ◽  
Author(s):  
Ekin Bolukbasi ◽  
Nathaniel S. Woodling ◽  
Dobril K. Ivanov ◽  
Jennifer Adcott ◽  
Andrea Foley ◽  
...  
Keyword(s):  
Nervous System ◽  
Transcription Factors ◽  
Cell Types ◽  
Growth Factor Signaling ◽  
Cell Type ◽  
Model Of Alzheimer’S Disease ◽  
Distinct Cell ◽  
Evolutionarily Conserved ◽  
Cell Type Specific ◽  
Specific Mapping

Reduced activity of insulin/insulin-like growth factor signaling (IIS) increases healthy lifespan among diverse animal species. Downstream of IIS, multiple evolutionarily conserved transcription factors (TFs) are required; however, distinct TFs are likely responsible for these effects in different tissues. Here we have asked which TFs can extend healthy lifespan within distinct cell types of the adult nervous system in Drosophila. Starting from published single-cell transcriptomic data, we report that forkhead (FKH) is endogenously expressed in neurons, whereas forkhead-box-O (FOXO) is expressed in glial cells. Accordingly, we find that neuronal FKH and glial FOXO exert independent prolongevity effects. We have further explored the role of neuronal FKH in a model of Alzheimer’s disease-associated neuronal dysfunction, where we find that increased neuronal FKH preserves behavioral function and reduces ubiquitinated protein aggregation. Finally, using transcriptomic profiling, we identify Atg17, a member of the Atg1 autophagy initiation family, as one FKH-dependent target whose neuronal overexpression is sufficient to extend healthy lifespan. Taken together, our results underscore the importance of cell type-specific mapping of TF activity to preserve healthy function with age.

scholarly journals Cell-type specific epigenetic links to schizophrenia risk in brain

2019 ◽  
Author(s):  
Isabel Mendizabal ◽  
Stefano Berto ◽  
Noriyoshi Usui ◽  
Kazuya Toriumi ◽  
Paramita Chatterjee ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cell Types ◽  
Epigenetic Variation ◽  
Transcriptome Data ◽  
Cell Type ◽  
Coding Regions ◽  
Methylation Difference ◽  
Distinct Cell ◽  
Cell Type Specific ◽  
Targeted Deep Sequencing

AbstractThe importance of cell-type specific epigenetic variation of non-coding regions in neuropsychiatric disorders is increasingly appreciated, yet data from disease brains are conspicuously lacking. We generated cell-type specific whole-genome methylomes (N=95) and transcriptomes (N=89) from neurons and oligodendrocytes from brains of schizophrenia and matched controls. The methylomes of these two cell-types are highly distinct, with the majority of differential DNA methylation occurring in non-coding regions. DNA methylation difference between control and schizophrenia brains is subtle compared to cell-type difference, yet robust against permuted data and validated in targeted deep-sequencing analyses. Differential DNA methylation between control and schizophrenia tends to occur in cell-type differentially methylated sites, highlighting the significance of cell-type specific epigenetic dysregulation in a complex neuropsychiatric disorder. Our resource provides novel and comprehensive methylome and transcriptome data from distinct cell populations from schizophrenia brains, further revealing reduced cell-type epigenetic distinction in schizophrenia.

scholarly journals Cell type-dependent effects of ellagic acid on cellular metabolism

2018 ◽  
Author(s):  
Alexandra L. Boehning ◽  
Safia A. Essien ◽  
Erica L. Underwood ◽  
Pramod K. Dash ◽  
Darren Boehning
Keyword(s):  
Mitochondrial Function ◽  
Ellagic Acid ◽  
Cell Types ◽  
Cellular Respiration ◽  
Cell Type ◽  
Specific Effects ◽  
Cell Type Specific ◽  
High Doses

AbstractEllagic acid is a botanical polyphenol which has been shown to have numerous effects on cellular function. Ellagic acid can induce apoptosis and inhibit the proliferation of various cancer cell types in vitro and in vivo. As such, ellagic acid has attracted significant interest as a potential chemotherapeutic compound. One mechanism by which ellagic acid has been proposed to affect cellular physiology is by regulating metabolic pathways. Here we show the dose-dependent effects of ellagic acid on cellular energy production and downstream induction of the apoptotic program in HEK293, HeLa, MCF7, and HepG2 cells. At physiologically relevant doses, eallgic acid has pleiotropic and cell-type specific effects on mitochondrial function. At high doses ellagic acid can also influence glycolytic pathways and induce cell death. Our results demonstrate that ellagic acid can influence mitochondrial function at therapeutically relevant concentrations. The observed effects of ellagic acid on cellular respiration are complex and cell type-specific, which may limit the chemotherapeutic utility of this compound.

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