scholarly journals Cell type specific gene expression profiling reveals a role for complement component C3 in neutrophil responses to tissue damage

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ruth A. Houseright ◽  
Emily E. Rosowski ◽  
Pui-Ying Lam ◽  
Sebastien J. M. Tauzin ◽  
Oscar Mulvaney ◽  
...  

Abstract Tissue damage induces rapid recruitment of leukocytes and changes in the transcriptional landscape that influence wound healing. However, the cell-type specific transcriptional changes that influence leukocyte function and tissue repair have not been well characterized. Here, we employed translating ribosome affinity purification (TRAP) and RNA sequencing, TRAP-seq, in larval zebrafish to identify genes differentially expressed in neutrophils, macrophages, and epithelial cells in response to wounding. We identified the complement pathway and c3a.1, homologous to the C3 component of human complement, as significantly increased in neutrophils in response to wounds. c3a.1−/− zebrafish larvae have impaired neutrophil directed migration to tail wounds with an initial lag in recruitment early after wounding. Moreover, c3a.1−/− zebrafish larvae have impaired recruitment to localized bacterial infections and reduced survival that is, at least in part, neutrophil mediated. Together, our findings support the power of TRAP-seq to identify cell type specific changes in gene expression that influence neutrophil behavior in response to tissue damage.

2019 ◽  
Author(s):  
Ruth A. Houseright ◽  
Emily E. Rosowski ◽  
Pui Ying Lam ◽  
Sebastien JM Tauzin ◽  
Oscar Mulvaney ◽  
...  

AbstractFollowing acute injury, leukocytes rapidly infiltrate into tissues. For efficient recruitment, leukocytes must sense and respond to signals from both from the damaged tissue and from one another. However, the cell type specific transcriptional changes that influence leukocyte recruitment and wound healing have not been well characterized. In this study, we performed a large-scale translating ribosome affinity purification (TRAP) and RNA sequencing screen in larval zebrafish to identify genes differentially expressed by neutrophils, macrophages, and epithelial cells in the context of wounding. We identified the complement pathway and c3a.1, homologous to the C3A component of human complement, as significantly increased in neutrophils in response to a wound. We report that c3a.1−/− zebrafish larvae have impaired neutrophil responses to both tail wounds and localized bacterial infections, as well as increased susceptibility to infection due to a neutrophil-intrinsic function of C3A. We further show that C3A enhances migration of human primary neutrophils to IL-8 and that c3a.1−/− larvae have impaired neutrophil migration in vivo, and a decrease in neutrophil directed migration speed early after wounding. Together, our findings suggest a role for C3A in mediating efficient neutrophil migration to damaged tissues and support the power of TRAP to identify cell-specific changes in gene expression associated with wound-associated inflammation.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ana J. Chucair-Elliott ◽  
Sarah R. Ocañas ◽  
David R. Stanford ◽  
Victor A. Ansere ◽  
Kyla B. Buettner ◽  
...  

AbstractEpigenetic regulation of gene expression occurs in a cell type-specific manner. Current cell-type specific neuroepigenetic studies rely on cell sorting methods that can alter cell phenotype and introduce potential confounds. Here we demonstrate and validate a Nuclear Tagging and Translating Ribosome Affinity Purification (NuTRAP) approach for temporally controlled labeling and isolation of ribosomes and nuclei, and thus RNA and DNA, from specific central nervous system cell types. Analysis of gene expression and DNA modifications in astrocytes or microglia from the same animal demonstrates differential usage of DNA methylation and hydroxymethylation in CpG and non-CpG contexts that corresponds to cell type-specific gene expression. Application of this approach in LPS treated mice uncovers microglia-specific transcriptome and epigenome changes in inflammatory pathways that cannot be detected with tissue-level analysis. The NuTRAP model and the validation approaches presented can be applied to any brain cell type for which a cell type-specific cre is available.


2020 ◽  
Author(s):  
Nil Aygün ◽  
Angela L. Elwell ◽  
Dan Liang ◽  
Michael J. Lafferty ◽  
Kerry E. Cheek ◽  
...  

SummaryInterpretation of the function of non-coding risk loci for neuropsychiatric disorders and brain-relevant traits via gene expression and alternative splicing is mainly performed in bulk post-mortem adult tissue. However, genetic risk loci are enriched in regulatory elements of cells present during neocortical differentiation, and regulatory effects of risk variants may be masked by heterogeneity in bulk tissue. Here, we map e/sQTLs and allele specific expression in primary human neural progenitors (n=85) and their sorted neuronal progeny (n=74). Using colocalization and TWAS, we uncover cell-type specific regulatory mechanisms underlying risk for these traits.


2021 ◽  
Author(s):  
Dionnet L Bhatti ◽  
Lucian Medrihan ◽  
Michelle X Chen ◽  
Junghee Jin ◽  
Kathryn McCabe ◽  
...  

BACKGROUND: Behavioral responses to stress are, in part, mediated by the hippocampus and Parvalbumin (PV)-expressing neurons. However, whether chronic stress induces molecular and cellular adaptations in hippocampal PV neurons contribute to stress-induced behavioral outcomes remains elusive. METHOD: Using chronic social defeat stress (CSDS), we investigated the role of neuronal activity and gene expression in hippocampal PV neurons in mediating stress-resilience and -susceptibility. We first used in vivo high-density silicon probe recordings and chemogenetics to test whether the activity of PV neurons in ventral dentate gyrus (PVvDG) is associated with particular behavioral outcomes. To find critical molecular pathways associated with stress-resilience and -susceptibility, we used PV-neuron-selective translating ribosome affinity purification and RNAseq. We used immunoblotting, RNAscope, and region- or cell type-specific gene deletion to determine whether Ahnak, a molecule regulating depression-like behavior, was necessary for behavioral divergence after CSDS. RESULTS: We find CSDS modulates neuronal activity in vDG. Notably, stress-susceptibility is associated with an increase of PVvDG firing, which we find is necessary and sufficient for susceptibility. Additionally, genes involved in mitochondrial function, protein synthesis and synaptogenesis are differentially expressed in hippocampal PV neurons of stress-resilient and -susceptible mice. Interestingly, protein and mRNA levels of Ahnak, an endogenous regulator of L-type calcium channels are associated with susceptibility after CSDS. vDG- and PV cell type-specific deletions reveal that Ahnak is required for stress-susceptibility to CSDS. CONCLUSIONS: These findings indicate that CSDS-induced molecular and cellular adaptations in hippocampal PV neurons mediate behavioral consequences, proposing a mechanism underlying individual differences in stress vulnerability.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Takashi Ikeda ◽  
Takafusa Hikichi ◽  
Hisashi Miura ◽  
Hirofumi Shibata ◽  
Kanae Mitsunaga ◽  
...  

Author(s):  
Jieru Li ◽  
Alexandros Pertsinidis

Establishing cell-type-specific gene expression programs relies on the action of distal enhancers, cis-regulatory elements that can activate target genes over large genomic distances — up to Mega-bases away. How distal enhancers physically relay regulatory information to target promoters has remained a mystery. Here, we review the latest developments and insights into promoter–enhancer communication mechanisms revealed by live-cell, real-time single-molecule imaging approaches.


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