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 ◽  
...  

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.

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Nathaniel S. Woodling ◽  
Arjunan Rajasingam ◽  
Lucy J. Minkley ◽  
Alberto Rizzo ◽  
Linda Partridge

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.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yujuan Gui ◽  
Kamil Grzyb ◽  
Mélanie H. Thomas ◽  
Jochen Ohnmacht ◽  
Pierre Garcia ◽  
...  

Abstract Background Cell types in ventral midbrain are involved in diseases with variable genetic susceptibility, such as Parkinson’s disease and schizophrenia. Many genetic variants affect regulatory regions and alter gene expression in a cell-type-specific manner depending on the chromatin structure and accessibility. Results We report 20,658 single-nuclei chromatin accessibility profiles of ventral midbrain from two genetically and phenotypically distinct mouse strains. We distinguish ten cell types based on chromatin profiles and analysis of accessible regions controlling cell identity genes highlights cell-type-specific key transcription factors. Regulatory variation segregating the mouse strains manifests more on transcriptome than chromatin level. However, cell-type-level data reveals changes not captured at tissue level. To discover the scope and cell-type specificity of cis-acting variation in midbrain gene expression, we identify putative regulatory variants and show them to be enriched at differentially expressed loci. Finally, we find TCF7L2 to mediate trans-acting variation selectively in midbrain neurons. Conclusions Our data set provides an extensive resource to study gene regulation in mesencephalon and provides insights into control of cell identity in the midbrain and identifies cell-type-specific regulatory variation possibly underlying phenotypic and behavioural differences between mouse strains.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Kathryn M. Madalena ◽  
Jessica K. Lerch

Stress, injury, and disease trigger glucocorticoid (GC) elevation. Elevated GCs bind to the ubiquitously expressed glucocorticoid receptor (GR). While GRs are in every cell in the nervous system, the expression level varies, suggesting that diverse cell types react differently to GR activation. Stress/GCs induce structural plasticity in neurons, Schwann cells, microglia, oligodendrocytes, and astrocytes as well as affect neurotransmission by changing the release and reuptake of glutamate. While general nervous system plasticity is essential for adaptation and learning and memory, stress-induced plasticity is often maladaptive and contributes to neuropsychiatric disorders and neuropathic pain. In this brief review, we describe the evidence that stress/GCs activate GR to promote cell type-specific changes in cellular plasticity throughout the nervous system.


2021 ◽  
Vol 15 ◽  
Author(s):  
Mingchao Li ◽  
Qing Min ◽  
Matthew C. Banton ◽  
Xinpeng Dun

Advances in single-cell RNA sequencing technologies and bioinformatics methods allow for both the identification of cell types in a complex tissue and the large-scale gene expression profiling of various cell types in a mixture. In this report, we analyzed a single-cell RNA sequencing (scRNA-seq) dataset for the intact adult mouse sciatic nerve and examined cell-type specific transcription factor expression and activity during peripheral nerve homeostasis. In total, we identified 238 transcription factors expressed in nine different cell types of intact mouse sciatic nerve. Vascular smooth muscle cells have the lowest number of transcription factors expressed with 17 transcription factors identified. Myelinating Schwann cells (mSCs) have the highest number of transcription factors expressed, with 61 transcription factors identified. We created a cell-type specific expression map for the identified 238 transcription factors. Our results not only provide valuable information about the expression pattern of transcription factors in different cell types of adult peripheral nerves but also facilitate future studies to understand the function of key transcription factors in the peripheral nerve homeostasis and disease.


2021 ◽  
Author(s):  
Kapil Gupta ◽  
Christine Toelzer ◽  
Maia Kavanagh Williamson ◽  
Deborah Shoemark ◽  
A. Sofia F. Oliveira ◽  
...  

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.


1990 ◽  
Vol 111 (1) ◽  
pp. 209-215 ◽  
Author(s):  
A da Cunha ◽  
L Vitković

Growth-associated protein 43 (GAP-43) is an abundant, intensely investigated membrane phosphoprotein of the nervous system (Benowitz, L.I., and A. Routtenberg. 1987. Trends Neurosci. 10:527-532; Skene, J. H. P. 1989. Annu. Rev. Neurosci. 12:127-156), with a hitherto unknown function. We have previously demonstrated that astrocytes, brain macroglial cells, contain GAP-43 (Steisslinger, H. W., V. J. Aloyo, and L. Vitković, 1987. Brain Res. 415:375-379; Vitković, L., H. W. Steisslinger, V. J. Aloyo, and M. Mersel. 1988. Proc. Natl. Acad. Sci. USA. 85:8296-8300; Vitković L., and M. Mersel. 1989. Metab. Brain Dis. 4:47-53). Results from double immunofluorescent labeling experiments presented here show that oligodendrocytes also contain GAP-43 immunoreactivity (GAP-43ir). Thus, all three macroglial cell types of the central nervous system (type I and type 2 astrocytes and oligodendrocytes) contain GAP-43. Whereas immunoreactive GAP-43 is expressed by progenitors of all macroglial cell types, the developmental regulation of its expression is cell type specific. Immunoreactive GAP-43 is downregulated in type 1 astrocytes, and constitutively expressed in both type 2 astrocytes and oligodendrocytes. These results may be relevant to potential function(s) of GAP-43.


Microbiology ◽  
2009 ◽  
Vol 155 (6) ◽  
pp. 1786-1799 ◽  
Author(s):  
Catriona Donovan ◽  
Marc Bramkamp

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.


2010 ◽  
Vol 191 (3) ◽  
pp. 479-492 ◽  
Author(s):  
Rebecca M. Fox ◽  
Caitlin D. Hanlon ◽  
Deborah J. Andrew

Secretion occurs in all cells, with relatively low levels in most cells and extremely high levels in specialized secretory cells, such as those of the pancreas, salivary, and mammary glands. How secretory capacity is selectively up-regulated in specialized secretory cells is unknown. Here, we find that the CrebA/Creb3-like family of bZip transcription factors functions to up-regulate expression of both the general protein machinery required in all cells for secretion and of cell type–specific secreted proteins. Drosophila CrebA directly binds the enhancers of secretory pathway genes and is both necessary and sufficient to activate expression of every secretory pathway component gene examined thus far. Microarray profiling reveals that CrebA also up-regulates expression of genes encoding cell type–specific secreted components. Finally, we found that the human CrebA orthologues, Creb3L1 and Creb3L2, have the ability to up-regulate the secretory pathway in nonsecretory cell types.


2020 ◽  
Author(s):  
Quan Xu ◽  
Georgios Georgiou ◽  
Gert Jan C. Veenstra ◽  
Huiqing Zhou ◽  
Simon J. van Heeringen

AbstractProper cell fate determination is largely orchestrated by complex gene regulatory networks centered around transcription factors. However, experimental elucidation of key transcription factors that drive cellular identity is currently often intractable. Here, we present ANANSE (ANalysis Algorithm for Networks Specified by Enhancers), a network-based method that exploits enhancer-encoded regulatory information to identify the key transcription factors in cell fate determination. As cell type-specific transcription factors predominantly bind to enhancers, we use regulatory networks based on enhancer properties to prioritize transcription factors. First, we predict genome-wide binding profiles of transcription factors in various cell types using enhancer activity and transcription factor binding motifs. Subsequently, applying these inferred binding profiles, we construct cell type-specific gene regulatory networks, and then predict key transcription factors controlling cell fate conversions using differential gene networks between cell types. This method outperforms existing approaches in correctly predicting major transcription factors previously identified to be sufficient for trans-differentiation. Finally, we apply ANANSE to define an atlas of key transcription factors in 18 normal human tissues. In conclusion, we present a ready-to-implement computational tool for efficient prediction of transcription factors in cell fate determination and to study transcription factor-mediated regulatory mechanisms. ANANSE is freely available at https://github.com/vanheeringen-lab/ANANSE.


2019 ◽  
Author(s):  
Isabel Mendizabal ◽  
Stefano Berto ◽  
Noriyoshi Usui ◽  
Kazuya Toriumi ◽  
Paramita Chatterjee ◽  
...  

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.


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