Biology subjects

Vellingiri, V.

Publications and source records attributed to Vellingiri, V..

4 recordsLinked to original sources

bioRxiv2025

A Single Mutation in TRPC6 Protects Mice from Acute Lung Injury by Regenerating Endothelium

Regenerating vascular endothelium under sepsis, trauma, and viral infections is vital for promoting the resolution of inflammatory diseases such as acute lung injury (ALI). Transient receptor potential canonical (TRPC) channels mediated Ca2+ entry compromises organ functions and survival from lung injury. Through decoding the domain in TRPC6 responsible for vascular injury, we unveiled the intricate molecular mechanisms underlying vascular regeneration in injured tissue. We found that the substitution of isoleucine111 within the Ist ankyrin domain of TRPC6 for its isomer 111leucine (I111L-TRPC6) altered channel localization at the membrane, blocked TRPC6-mediated Ca2+ entry and cation currents without affecting TRPC6 protein expression. Next, we delivered WT-TRPC6 and I111L-TRPC6 to the endothelial cells (ECs) of TRPC6 knockout mice using liposomes and found that while WT-TRPC6 induced lung vascular inflammatory injury and EC death these responses were blocked in lungs expressing I111L-TRPC6 mutant. Instead, the I111L-TRPC6 mutant promoted lung EC proliferation and prevented vascular injury. These responses were recapitulated in a preclinical mouse model of ALI after injection of engineered TRPC6-blocking peptide, suggesting a novel strategy for regenerating anti-inflammatory vascular niche and preventing ALI therapeutically.

cell biology↗

bioRxiv2024

Endothelial ERG programs neutrophil transcriptome for sustained anti-inflammatory vascular niche

Neutrophils (PMNs) reside as a marginated pool within the vasculature, ready for deployment during infection. However, how endothelial cells (ECs) control PMN extravasation and activation to strengthen tissue homeostasis remains ill-defined. Here, we found that the vascular ETS-related gene (ERG) is a generalized mechanism regulating PMN activity in preclinical tissue injury models and human patients. We show that ERG loss in ECs rewired PMN-transcriptome, enriched for genes associated with the CXCR2-CXCR4 signaling. Rewired PMNs compromise mice survival after pneumonia and induced lung vascular inflammatory injury following adoptive transfer into naive mice, indicating their longevity and inflammatory activity memory. Mechanistically, EC-ERG restricted PMN extravasation and activation by upregulating the deubiquitinase A20 and downregulating the NF{kappa}B-IL8 cascade. Rescuing A20 in EC-Erg-/- endothelium or suppressing PMN-CXCR2 signaling rescued EC control of PMN activation. Findings deepen our understanding of EC control of PMN-mediated inflammation, offering potential avenues for targeting various inflammatory diseases. HighlightsO_LIERG regulates trans-endothelial neutrophil (PMN) extravasation, retention, and activation C_LIO_LILoss of endothelial (EC) ERG rewires PMN-transcriptome C_LIO_LIAdopted transfer of rewired PMNs causes inflammation in a naive mouse C_LIO_LIERG transcribes A20 and suppresses CXCR2 function to inactivate PMNs C_LI In brief/blurbThe authors investigated how vascular endothelial cells (EC) control polymorphonuclear neutrophil (PMN) extravasation, retention, and activation to strengthen tissue homeostasis. They showed that EC-ERG controls PMN transcriptome into an anti-adhesive and anti-inflammatory lineage by synthesizing A20 and suppressing PMNs-CXCR2 signaling, defining EC-ERG as a target for preventing neutrophilic inflammatory injury.

immunology↗

bioRxiv2023

RGS2 is an innate immune checkpoint for TLR4 and Gαq-mediated IFNγ generation and lung injury

IFN{gamma}, a type II interferon secreted by immune cells, augments tissue responses to injury following pathogenic infections leading to lethal acute lung injury (ALI). Alveolar macrophages (AM) abundantly express Toll-like receptor-4 and represent the primary cell type of the innate immune system in the lungs. A fundamental question remains whether AM generation of IFNg leads to uncontrolled innate response and perpetuated lung injury. LPS induced a sustained increase in IFNg levels and unresolvable inflammatory lung injury in the mice lacking RGS2 but not in RGS2 null chimeric mice receiving WT bone marrow or receiving the RGS2 gene in AM. Thus, indicating RGS2 serves as a gatekeeper of IFNg levels in AM and thereby lungs innate immune response. RGS2 functioned by forming a complex with TLR4 shielding Gaq from inducing IFNg generation and AM inflammatory signaling. Thus, inhibition of Gaq blocked IFNg generation and subverted AM transcriptome from being inflammatory to reparative type in RGS2 null mice, resolving lung injury. HighlightsO_LIRGS2 levels are inversely correlated with IFN{gamma} in ARDS patients AM. C_LIO_LIRGS2 in alveolar macrophages regulate the inflammatory lung injury. C_LIO_LIDuring pathogenic insult RGS2 functioned by forming a complex with TLR4 shielding Gq from inducing IFN{gamma} generation and AM inflammatory signaling. C_LI eToc BlurbAuthors demonstrate an essential role of RGS2 in macrophages in airspace to promoting anti-inflammatory function of alveolar macrophages in lung injury. The authors provided new insight into the dynamic control of innate immune response by Gq and RGS2 axis to prevent ALI.

immunology↗

bioRxiv2023

Tension sensing by FAK governs nuclear mechanotransduction, endothelial transcriptome and fate

Vascular endothelium forms a restrictive barrier to defend the underlying tissue against uncontrolled influx of circulating protein and immune cells. Mechanisms that mediate the transition from restrictive to leaky endothelium, a hallmark of tissue injury exemplified by acute lung injury (ALI), remain elusive. Using endothelial cell (EC)-Fak-/-mice, we show that FAK sensing and transmission of mechanical tension to the EC nucleus governs cell fate. In FAK- deleted EC, increased EC tension induced by Rho kinase caused tyrosine phosphorylation of nuclear envelope protein, emerin at Y74/Y95, and its localization in a nuclear cap. Activated emerin stimulated DNMT3a activity and methylation of the KLF2 promoter, impairing the restrictive EC transcriptome, including S1PR1. Inhibiting emerin phosphorylation or DNMT3a activity enabled KLF2 transcription of S1PR1, rescuing the restrictive EC phenotype in EC-Fak-/- lungs. Thus, FAK sensing of tension transmission to the nucleus is crucial for maintaining a restrictive EC fate and lung homeostasis.

cell biology↗