DNAJA1‑knockout alleviates heat stroke‑induced endothelial barrier disruption via improving thermal tolerance and suppressing the MLCK‑MLC signaling pathway

Abstract

endothelial barrier disruption plays a key role in the pathophysiology of heat stroke (HS). Knockout of dnaJa1 (dnaJa1-Ko) is thought to be protective against HS based on a genome-wide criSPr-cas9 screen experiment. The present study aimed to illustrate the function of dnaJa1-Ko against HS in human umbilical vein endothelial cells. dnaJa1-Ko cells were infected using a lentivirus to investigate the role of dnaJa1-Ko in HS-induced endothelial barrier disruption. it was shown that dnaJa1-Ko could ameliorate decreased cell viability and increased cell injury, according to the results of cell counting Kit-8 and lactate dehydrogenase assays. Moreover, HS-induced endothelial cell apoptosis was inhibited by dnaJa1-Ko, as indicated by annexin V-FiTc/Pi staining and cleaved-caspase-3 expression using flow cytometry and western blotting, respectively. Furthermore, the endothelial barrier function, as measured by transepithelial electrical resistance and FiTc-dextran, was sustained during HS. DNAJA1-KO was not found to have a significant effect on the expression and distribution of cell junction proteins under normal conditions without HS. However, dnaJa1-Ko could effectively protect the HS-induced decrease in the expression and distribution of cell junction proteins, including zonula occludens-1, claudin-5, junctional adhesion molecule a and occludin. A total of 4,394 proteins were identified using proteomic analysis, of which 102 differentially expressed proteins (dePs) were activated in HS-induced wild-type cells and inhibited by dnaJa1-Ko. dePs were investigated by enrichment analysis, which demonstrated significant enrichment in the 'calcium signaling pathway' and associations with vascular-barrier regulation. Furthermore, the 'myosin light-chain kinase (MlcK)-Mlc signaling pathway' was proven to be activated by HS and inhibited by dnaJa1-Ko, as expected. Moreover, dnaJa1-Ko mice and a HS mouse model were established to demonstrate the protective effects on endothelial barrier in vivo. in conclusion, the results of the present study suggested that dnaJa1-Ko alleviates HS-induced endothelial barrier disruption by improving thermal tolerance and suppressing the MlcK-Mlc signaling pathway.

Heat acclimation with probiotics-based ORS supplementation alleviates heat stroke-induced multiple organ dysfunction via improving intestinal thermotolerance and modulating gut microbiota in rats

“…All of the organ tissues were treated according to our previously described protocol ( Li et al, 2021 ; Li L et al, 2024 ). Briefly, the organ samples were fixed, dehydrated, embedded, sectioned and stained with Hematoxylin and Eosin (H&E).…”