{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nCeramide synthase 1 (CERS1), a mammalian homolog of the longevity assurance (LAG1/LASS1/UOG1) family, is a key enzyme in the acyl‐CoA–dependent synthesis of ceramides, with a striking specificity for generating C18‐ceramide. Early studies showed that overexpression of UOG1 in mammalian cells confers resistance to inhibitors of ceramide synthesis and redirects ceramide into neutral glycosphingolipids, thereby impacting cell proliferation and survival."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nCERS1 function is dynamically regulated in response to cellular stress. Under diverse stress conditions, the enzyme is susceptible to proteasome‐dependent cleavage leading to its translocation away from the endoplasmic reticulum. This proteolytic processing is critical in modulating ceramide homeostasis and ensuring that the specific generation of C18‐ceramide is appropriately tuned to environmental cues."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nGenetic variation within the CERS1 gene, historically known as LASS1, has emerged as an important determinant of healthy aging. Specific functional haplotypes that upregulate CERS1 expression are associated with enhanced production of C18‐ceramide, modulation of telomerase activity, and protection against cellular damage—all of which contribute to greater longevity."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "4"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nEpigenetic mechanisms further influence CERS1 activity. In certain cancer contexts, a histone deacetylase 1–dependent pathway, in conjunction with targeting by microRNA-574-5p, represses the CerS1 gene. This downregulation diminishes C18-ceramide synthesis, thereby facilitating drug resistance and metastatic progression in tumor cells while highlighting the enzyme’s role as a tumor suppressor."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "5"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn neurological settings, deficits in lysosomal proteins such as CLN5 and CLN8—which are implicated in neurodegenerative disorders—can be partially corrected by the actions of CerS1. By restoring sphingolipid production, particularly of C18‐ceramide, CerS1 contributes to re‐establishing cellular homeostasis in neural tissues."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "6"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nAssociations between CERS1 gene variants and markers of muscle tissue damage further underscore its physiological significance. Specific alleles have been linked to alterations in creatine kinase levels, suggesting that proper CERS1 function helps mitigate muscle injury and maintain tissue integrity."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "7"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn the realm of endocrine tumors, notably hypophysomas, CERS1 overexpression has been shown to curtail tumor growth. Mechanistically, increased CERS1 activity enhances autophagy through modulation of the PI3K/AKT signaling pathway, thereby inhibiting cell proliferation and invasion in these pituitary neoplasms."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "8"}]}, {"type": "t", "text": ""}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nFinally, age-related skeletal muscle impairment is linked to declining CERS1 expression. Both pharmacologic and genetic inhibition of CERS1 in animal models impair myogenesis and exacerbate muscle wasting, while human genetic studies further associate reduced CERS1 expression with diminished grip strength and overall muscle health in the elderly."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "9"}]}, {"type": "t", "text": ""}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Krishnan Venkataraman, Christian Riebeling, Jacques Bodennec, et al. 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