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Anisimov, A.

Publications and source records attributed to Anisimov, A..

3 recordsLinked to original sources

ATG-18 drives longevity in an HLH-30-dependent manner

Enhancing autophagy increases lifespan and healthspan in animal models, yet the precise molecular mechanisms underlying these effects are not fully understood. Here we show that overexpression of the essential autophagic gene atg-18 extends the lifespan of C. elegans. We describe a previously unknown, pleiotropic mechanism by which atg-18 impacts lysosomes and extends lifespan through the transcription factor hlh-30, the master regulator of lysosomal biogenesis. We show that, under stress conditions, HLH-30 requires atg-18 for nuclear translocation. Furthermore, atg-18 overexpression broadly improves health and stress resilience yet paradoxically increases early-life susceptibility to lethal heat stress. In contrast, enhances heat-stress survival a loss-of-function of function mutation in atg-18 enhances heat-stress survival, uncovering a temporal-specific effect of atg-18. These finding suggest an ATG-18--HLH-30 autophagy--lysosome pathway that plays a key role in lifespan and healthspan. Bulleted main discoveriesO_LIATG-18 overexpression increases C. elegans lifespan and plays an important role in resilience against starvation and heat stress. C_LIO_LIATG-18 is required for nuclear translocation of HLH-30 C_LIO_LIHLH-30 is required for ATG-18--mediated lifespan extension C_LIO_LIATG-18 positively regulates lysosomal biogenesis, suggesting a novel role as a molecular coordinator between autophagy and the lysosomal network. C_LI

molecular biology↗

Cardiovascular disease risk factors induce mesenchymal features and senescence in cardiac endothelial cells

Aging, obesity, hypertension and physical inactivity are major risk factors for endothelial dysfunction and cardiovascular disease (CVD). We applied fluorescence-activated cell sorting (FACS), RNA sequencing and bioinformatic methods to investigate the common effects of CVD risk factors on cardiac endothelial cells (ECs). Aging, obesity and pressure overload all upregulated pathways related to TGF-{beta} signaling and mesenchymal gene expression, inflammation, vascular permeability, oxidative stress, collagen synthesis and cellular senescence, whereas exercise training downregulated most of the same pathways. We identified collagen chaperone SerpinH1/HSP47 to be significantly increased by aging and obesity and repressed by exercise training. Mechanistic studies demonstrated that SERPINH1/HSP47 in human ECs changed cell morphology and increased mesenchymal gene expression, while its silencing inhibited collagen deposition. Our data demonstrate that CVD risk factors significantly remodel the transcriptomic landscape of cardiac ECs to acquire senescence and mesenchymal features. SERPINH1/HSP47 was identified as a potential therapeutic target in ECs.

molecular biology↗

Pericyte-specific vascular expression of SARS-CoV-2 receptor ACE2 - implications for microvascular inflammation and hypercoagulopathy in COVID-19 patients

Accumulating clinical observations implicate vascular inflammation as an underlying cause of coagulopathy in severely ill COVID-19 patients and it was recently suggested that SARS-CoV-2 virus particles infect endothelial cells. Here, we show that endothelial cells do not express angiotensin-converting enzyme-2 (ACE2), the SARS-CoV-2 receptor. Instead, pericytes and microvascular smooth muscle cells express ACE2 in an organotypic manner. Pericyte deficiency leads to increased endothelial expression and release of Von Willebrand factor and intravascular platelet and fibrin aggregation, suggesting that pericytes limit endothelial pro-thrombotic responses. That pericytes and not endothelial cells express ACE2 may provide important clues to the pathology of COVID-19, as pericytes are normally shielded behind an endothelial barrier and may get infected only when this barrier is compromised by COVID-19 risk factors.

pathology↗