TLR4 and metabolic syndrome: Excessive consumption of sugars and long-chain saturated fatty acids was closely associated with lipotoxicity and MetS, including Toll-like receptor 4 (Toll4) activation, regulation of peroxisome proliferator-activated receptor γ (PPARγ), sphingolipid remodeling, and activation of protein kinase C. These pathways are pivotal in promoting mitochondrial dysfunction, disrupting fatty acid and protein metabolism, and inducing insulin resistance (46).