Background Obesity has been identified as a risk factor for acute lung injury/acute respiratory distress syndrome (ALI/ARDS). However, the underlying mechanisms remain elusive. This study aimed to investigate the role of fatty acid synthase (FASN) in lipopolysaccharide (LPS)-induced ALI under obesity. Methods A high-fat diet-induced obese (DIO) mouse model was established and lean mice fed with regular chow diet were served as controls. LPS was intratracheally instilled to reproduce ALI in mice. In vitro, primary mouse lung endothelial cells (MLECs), treated by palmitic acid (PA) or co-cultured with 3T3-L1 adipocytes, were exposed to LPS. Chemical inhibitor C75 or shRNA targeting FASN was used for in vivo and in vitro loss-of-function studies for FASN. Results After LPS instillation, the protein levels of FASN in freshly isolated lung endothelial cells from DIO mice were significantly higher than those from lean mice. MLECs undergoing metabolic stress exhibited increased levels of FASN, decreased levels of VE-cadherin with increased p38 MAPK phosphorylation and NLRP3 expression, mitochondrial dysfunction, and impaired endothelial barrier compared with the control MLECs when exposed to LPS. However, these effects were attenuated by FASN inhibition with C75 or corresponding shRNA. In vivo, LPS-induced ALI, C75 pretreatment remarkably alleviated LPS-induced overproduction of lung inflammatory cytokines TNF-α, IL-6, and IL-1β, and lung vascular hyperpermeability in DIO mice as evidenced by increased VE-cadherin expression in lung endothelial cells and decreased lung vascular leakage. Conclusions Taken together, FASN inhibition alleviated the exacerbation of LPS-induced lung injury under obesity via rescuing lung endothelial dysfunction. Therefore, targeting FASN may be a potential therapeutic target for ameliorating LPS-induced ALI in obese individuals.
Mutations in superoxide dismutase 1 (SOD1) compromise its metal-binding capacity, resulting in protein misfolding and aggregation, which ultimately induces cellular apoptosis in amyotrophic lateral sclerosis (ALS). Copper metabolism domain containing 1 (COMMD1), a gene implicated in copper homeostasis, has not been thoroughly characterized in the context of ALS pathogenesis. In this study, we identified elevated COMMD1 expression in ALS, potentially contributing to diminished copper incorporation into SOD1. Knockdown of COMMD1 enhanced palmitoylation of the copper chaperone for SOD1 (CCS), facilitating its membrane translocation and promoting copper loading into SOD1, thereby conferring neuroprotection in ALS. Mechanistically, we established that COMMD1 knockdown augments CCS palmitoylation via activation of the hypoxia inducible factor 1 subunit alpha (HIF-1α)/fatty acid synthase (FASN) signaling axis. In vivo investigations utilizing male hSOD1G93A transgenic mice demonstrated that COMMD1 deficiency markedly ameliorated the deterioration of motor function and prolonged survival duration. These findings collectively suggest that COMMD1 represents a potential therapeutic target for ALS intervention.Significance Statement Superoxide dismutase 1 (SOD1) was the first identified mutant gene associated with amyotrophic lateral sclerosis (ALS). Mutations in SOD1 compromise its metal-binding function, resulting in neuronal apoptosis, a hallmark of ALS pathogenesis. Utilizing the SOD1G93A models of ALS, our findings revealed that COMMD1 deficiency significantly elevates copper incorporation into SOD1, consequently attenuating cellular apoptosis. These results suggest that targeted inhibition of COMMD1 could represent a potential therapeutic strategy for ALS treatment.
危险品化学品经营许可证（带存储）