La vitamine D pour la santé du foie?

[Nutrimuscle-Conseils]

Effect of vitamin D3 supplementation on hepatic lipid dysregulation associated with autophagy regulatory AMPK/Akt-mTOR signaling in type 2 diabetic mice
Hyewon Lim, Experimental Biology and Medicine Vol. 246, No. 10, May 1, 2021

Vitamin D3 has been reported to protect liver against non-alcoholic fatty liver disease (NAFLD) by attenuating hepatic lipid dysregulation in type 2 diabetes mellitus (T2DM). However, the mechanism of vitamin D3 on hepatic lipid metabolism-associated autophagy in hyperglycemia-induced NAFLD remains yet to be exactly elucidated. C57BL/6J mice were intraperitoneally injected with 30 mg/kg of streptozotocin and fed a high-fat diet for induction of diabetes. All mice were administered with vehicle or vitamin D3 (300 ng/kg or 600 ng/kg) by oral gavage for 12 weeks. Histological demonstrations of the hepatic tissues were obtained by H&E staining and the protein levels related to lipid metabolism and autophagy signaling were analyzed by Western blot. Treatment with vitamin D3 improved insulin resistance, liver damage, and plasma lipid profiles, and decreased hepatic lipid content in the diabetic mice. Moreover, vitamin D3 administration ameliorated hepatic lipid dysregulation by downregulating lipogenesis and upregulating lipid oxidation under diabetic condition. Importantly, vitamin D3 treatment induced autophagy by activating AMP-activated protein kinase (AMPK), inactivating Akt and ultimately blocking mammalian target of rapamycin (mTOR) activation in the T2DM mice. Additionally, vitamin D3 was found to be effective in anti-apoptosis and anti-fibrosis in the liver of diabetic mice.

The results suggested that vitamin D3 may ameliorate hepatic lipid dysregulation by activating autophagy regulatory AMPK/Akt-mTOR signaling in T2DM, providing insights into its beneficial effects on NAFLD in type 2 diabetic patients.

[Nutrimuscle-Conseils]

The Interplay of Vitamin D Deficiency and Cellular Senescence in The Pathogenesis of Obesity-Related Co-Morbidities
by Abdulhadi Bima Nutrients 2021, 13(11), 4127;

This scoping review aims to clarify the interplay between obesity, vitamin D deficiency, cellular senescence, and obesity-related metabolic consequences, mainly subclinical atherosclerosis, and non-alcoholic fatty liver disease (NAFLD). Obesity is a significant global health problem that involves cellular, environmental, behavioral, and genetic elements. The fundamental cause of obesity throughout all life stages is an energy imbalance, and its consequences are countless and, foremost, very common. Obesity has been comprehensively studied in the literature given its association with low serum vitamin D, with many proposed mechanisms linking the two conditions. Moreover, markers of exaggerated cellular senescence have been proven to accumulate in obese individuals.

Subclinical atherosclerosis initiates an early stage that ends in serious cardiac events, and obesity, low vitamin D, and senescent cells largely contribute to its associated chronic low-grade inflammation. Furthermore, NAFLD signifies the hepatic manifestation of metabolic syndrome, and studies have highlighted the important role of obesity, vitamin D deficiency, and cellular senescence in its development. Therefore, we outlined the most important mechanisms tying these conditions to one another.

[Nutrimuscle-Diététique]

Traduction de l'étude

L'interaction de la carence en vitamine D et de la sénescence cellulaire dans la pathogenèse des comorbidités liées à l'obésité
par Abdulhadi Bima Nutrients 2021, 13(11), 4127 ;

Cette revue de cadrage vise à clarifier l'interaction entre l'obésité, la carence en vitamine D, la sénescence cellulaire et les conséquences métaboliques liées à l'obésité, principalement l'athérosclérose infraclinique, et la stéatose hépatique non alcoolique (NAFLD). L'obésité est un problème de santé mondial important qui implique des éléments cellulaires, environnementaux, comportementaux et génétiques. La cause fondamentale de l'obésité à toutes les étapes de la vie est un déséquilibre énergétique, et ses conséquences sont innombrables et surtout très courantes. L'obésité a été largement étudiée dans la littérature étant donné son association avec un faible taux de vitamine D sérique, avec de nombreux mécanismes proposés liant les deux conditions. De plus, il a été prouvé que les marqueurs de sénescence cellulaire exagérée s'accumulent chez les individus obèses.

L'athérosclérose infraclinique initie un stade précoce qui se termine par des événements cardiaques graves, et l'obésité, une faible teneur en vitamine D et les cellules sénescentes contribuent largement à son inflammation chronique de bas grade associée. De plus, la NAFLD signifie la manifestation hépatique du syndrome métabolique, et des études ont mis en évidence le rôle important de l'obésité, de la carence en vitamine D et de la sénescence cellulaire dans son développement. Par conséquent, nous avons décrit les mécanismes les plus importants liant ces conditions les unes aux autres.