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Biology subjects

Traynor, S.

Publications and source records attributed to Traynor, S..

2 recordsLinked to original sources

SOX4 Reprograms Adipose Stromal Cells into a Cancer-Associated Fibroblast-like State to Drive Metabolic Disease

Pathogenic adipose tissue remodeling promotes metabolic disease in obesity, but the mechanisms that establish this unhealthy tissue state remain poorly understood. Here, we show that obesity drives SOX4-dependent reprogramming of mesenchymal stromal cells (MSCs) into cancer-associated fibroblast-like (CAF-like) cells that promote adipose tissue dysfunction. TGF{beta} signaling is elevated in obesity and activates SOX4 in mouse and human MSCs, inducing their conversion to a CAF-like state. In mice, MSC-specific SOX4 activation induces the CAF-like program and exacerbates adipose tissue inflammation and glucose intolerance, whereas Sox4 deletion attenuates inflammation and improves glucose homeostasis during obesity. We further identify the growth factor Midkine (MDK) as a SOX4-regulated paracrine effector produced by CAF-like cells. MDK inhibition in obese mice reduces adipose tissue inflammation and improves metabolic function. Together, these findings define a TGF{beta}-SOX4-MDK stromal signaling axis that drives pathological adipose tissue remodeling in obesity and highlight this pathway as a potential therapeutic target for improving metabolic health.

cell biology↗

Glucokinase activity suppresses hepatic cholesterol synthesis and triglyceride accumulation: A new model for the effects of the GKRP P466L common human variant

ObjectiveGlucokinase Regulatory Protein (GKRP) controls the activity of Glucokinase (GCK) to regulate liver glucose uptake and storage. Coding variants in GCKR, the gene encoding GKRP, strongly associate with fatty liver disease, hypertriglyceridemia, and hypercholesterolemia. Here, we sought to investigate the mechanisms by which a common GKRP variant affects hepatic lipid and cholesterol metabolism. MethodsWe developed mouse models to examine how the human GKRP P446L variant influences liver and systemic metabolism. Endogenous Gckr expression was ablated in adult mouse hepatocytes, together with re-expression of either human GKRP P446L or the reference GKRP protein. We assessed body weight, adiposity, systemic glucose homeostasis, and hepatic metabolites in mice expressing reference GKRP or GKRP P446L under multiple metabolic conditions. To determine whether the effects of GKRP P446L may result from reduced GCK activity, we analyzed mice with liver-specific deletion of Gck. ResultsHepatic expression of GKRP P446L resulted in reduced GKRP and GCK protein levels and elevated serum cholesterol. Hepatic deletion of Gck in mice recapitulated several effects of GKRP P446L, including increased hepatic cholesterol and triglyceride content. The elevated cholesterol was associated with increased cholesterogenic gene expression and cholesterol synthesis. Hepatic expression of an alternative hexokinase (HKII) normalized the effects of GCK-deficiency, suggesting that impaired glucose phosphorylation underlies the phenotype. ConclusionsThe GKRP P446L variant reduced GKRP protein abundance, and diminished GCK activity while increasing cholesterol levels. Loss of GCK elevated cholesterol and hepatic triglyceride levels. Collectively, these findings demonstrate that GCK suppresses hepatic cholesterol synthesis and lipid accumulation, suggesting that reduced GCK activity underlies the metabolic abnormalities associated with the GKRP P446L variant. HighlightsO_LIThe GKRP P446L variant reduces GKRP protein abundance and diminishes GCK activity. C_LIO_LIExpression of GKRP P446L in mouse hepatocytes increases serum cholesterol levels. C_LIO_LIGCK activity suppresses cholesterogenic gene expression and cholesterol synthesis. C_LI

physiology↗