GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE329nnn/GSE329246/primaryOK200TranscriptomicsBos taurusExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE329246GEOGSEfalseIndole-3-acetic acid alleviates palmitic acid-induced lipid accumulation and endoplasmic reticulum stress via sirtuin 3 in primary bovine hepatocytesKetotic cows experience severe negative energy balance, in which an increase in circulating non-esterified fatty acids (NEFA), particularly palmitic acid (PA), is a primary cause of liver damage. Although reports indicate that the endogenous tryptophan metabolite indole-3-acetic acid (3-IAA) can protect the liver of non-ruminant animals, its role in mitigating lipotoxicity-induced damage to bovine hepatocytes remains unclear. In this study, ketotic cows showed higher serum β-hydroxybutyrate and NEFA, lower 3-IAA and glucose concentrations, and increased hepatic triacylglycerol (TG) content, which was negatively correlated with serum 3-IAA. In primary bovine hepatocytes, treatment with 200 μmol/L 3-IAA improved cell viability, reduced cytotoxicity, and alleviated PA-induced lipid metabolic disorders and endoplasmic reticulum stress (ERS). RNA sequencing indicated that 3-IAA regulated pathways related to lipid metabolism and ERS. Mechanistically, 3-IAA attenuated PA-induced lipid accumulation, downregulated sterol regulatory element-binding protein 1 (SREBP-1) protein and acetyl-CoA carboxylase α (ACACA) or fatty acid synthase (FASN) mRNA, and concurrently increased peroxisome proliferator-activated receptor α (PPARα) and carnitine palmitoyltransferase 1A (CPT1A) protein abundance and CPT1A mRNA, suggesting reduced lipogenesis and enhanced fatty acid oxidation. In parallel, 3-IAA alleviated ER swelling and suppressed ERS at both the protein and gene levels by reducing the protein abundance of phosphorylated protein kinase R-like endoplasmic reticulum kinase (P-PERK), phosphorylated inositol-requiring enzyme 1α (P-IRE1α), and cleaved activating transcription factor 6 (ATF6) with gene expression of glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), and spliced X-box binding protein 1 (sXBP1). Notably, 3-IAA increased sirtuin 3 (SIRT3) mRNA and protein expression in PA-treated hepatocytes, whereas SIRT3 knockdown partially abolished its protective effects. Collectively, these findings indicate that 3-IAA mitigates PA-induced lipid accumulation and ERS via a SIRT3-dependent pathway in bovine hepatocytes, and suggest that 3-IAA may act as an endogenous regulator of hepatic homeostasis in ketotic cows.2026/07/01GSE329246GSM9700032GSM9700028GSM9700027GSM9700029GSM9700031GSM970003035707329246Bos taurus