Beclin 1 Recombinant Rabbit Monoclonal Antibody

Skeletal muscle atrophy, a debilitating complication of COPD, is closely linked to cigarette smoke (CS) exposure. The epigenetic regulator HDAC2 has been implicated, but the upstream regulatory mechanisms and precise downstream pathways are unclear. Using a CS-induced mouse atrophy model and C2C12 myotubes treated with cigarette smoke extract (CSE), we systematically investigated the role of USP47/HDAC2/CYP1A1/ROS axis through gain/loss-of-function studies, RNA-seq, ChIP-qPCR, co-immunoprecipitation, and ubiquitination assays. HDAC2 was downregulated in atrophic muscle, and its overexpression mitigated CS-induced atrophy, improved grip strength, and enhanced muscle regeneration. HDAC2 acted as a transcriptional repressor of CYP1A1 by deacetylating H3K9 and H3K27 at the promoter, thus curtailing ROS-driven excessive autophagy. We further discovered that the deubiquitinase USP47 is the key upstream regulator of HDAC2. USP47 directly interacted with HDAC2, promoted its deubiquitination, and enhanced its protein stability. Consequently, USP47 overexpression phenocopied the benefits of HDAC2 overexpression, which were effectively nullified by restoring CYP1A1 expression. In conclusion, we delineate a previously unrecognized signaling axis wherein USP47 stabilizes HDAC2 to inhibit the CYP1A1/ROS/autophagy cascade, ultimately protecting against CS-induced skeletal muscle atrophy. Targeting the USP47-HDAC2 interface presents a novel therapeutic strategy for combating muscle wasting in COPD.

Distal hereditary motor neuropathy (dHMN) is a progressive neurological disease characterized by distal limb muscle weakness and amyotrophy. Sigma 1 receptor (σ1R), a gene product of SIGMAR1, mutations have been reported to induce dHMN, but its mechanism remains unknown. This study aims to explore the effect of C238T and 31_50del mutations in σ1R on neuronal SH-SY5Y cell functions. The SH-SY5Y cells that overexpressed σ1R, C238T mutant σ1R (σ1R C238T ) or 31_50del mutant σ1R (σ1R 31_50del ) were constructed by pEGFPN1 vectors. We used Western blot (WB) and immunofluorescence (IF) staining to detect the expression of σ1R and green fluorescent proteins (GFP). Then, we evaluated the impact of σ1R mutation on apoptosis, autophagy, endoplasmic reticulum stress, and the involvement of the unfolded protein response (UPR) pathway in SH-SY5Y cells. We found that σ1R C238T and σ1R 31_50del downregulated σ1R and promoted the apoptosis of SH-SY5Y cells. σ1R C238T and σ1R 31_50del increased p-PERK, p-eIF2α, p-JNK, BIP, ATF4, CHOP, ATF6, XBP1, Caspase3, Caspase12 expressions and Ca 2+ concentration, whereas decreased ATP content in SH-SY5Y cells. Besides, the expressions of LC3B, Lamp1, ATG7, Beclin-1 and phosphorylation of AMPK and ULK1 were increased, while the p62 level decreased after C238T or 31_50del mutation of σ1R. Additionally, AMPK knockdown abolished the apoptosis mediated by σ1R C238T or σ1R 31_50del in SH-SY5Y cells. Our results indicated that C238T or 31_50del mutation in σ1R promoted motor neuron apoptosis through the AMPK/ULK1 pathway in dHMN. This study shed light on a better understanding of the neurons pathological mechanisms mediated by σ1R C238T and σ1R 31-50del in dHMN.