Project description:This study investigates the transcriptional consequences of an inducible deletion of RetSat in epithelial cells of the intestine. Kiefer MF et. al, American Journal of Physiology-Endocrinology and Metabolism, 2024
Project description:Diabetic cardiomyopathy (DCM) is a primary myocardial injury induced by diabetes mellitus (DM) with a complex pathogenesis. In this study, we identified disordered cardiac retinol metabolism in T2DM mice and patients characterized by retinol (vitamin A, Rol) overload, all-trans retinoic acid (atRA) deficiency and retinoic acid receptors (RARs) reduction, and demonstrated that both cardiac Rol overload and atRA deficiency promote DCM by supplementing T2DM mice with Rol or atRA. Mechanically, by constructing cardiomyocyte-specific conditional RDH10-knockout mice and overexpressing RDH10 in T2DM mice via adeno-associated virus, we verified that the reduction in cardiac retinol dehydrogenase 10 (RDH10) is the initiating factor for cardiac retinol metabolism disorder and its resulting DCM. Additionally, lipotoxicity and ferroptosis contribute to the effect of retinol metabolism disorder on DCM. Based on these results, we suggest that the reduction of cardiac RDH10 and its mediated disorder of cardiac retinol metabolism is a new mechanism underlying DCM.
Project description:Pigment regeneration is critical for the function of cone photoreceptors in bright and rapidly-changing light conditions. This process is facilitated by the recently-characterized retina visual cycle, in which Müller cells recycle spent all-trans-retinol visual chromophore back to 11-cis-retinol. This 11-cis-retinol is oxidized selectively in cones to the 11-cis-retinal used for pigment regeneration. However, the enzyme responsible for the oxidation of 11-cis-retinol remains unknown. Here, we sought to determine whether retinol dehydrogenase 10 (RDH10), upregulated in rod/cone hybrid retinas and expressed abundantly in Müller cells, is the enzyme that drives this reaction. We created mice lacking RDH10 either in cone photoreceptors, Müller cells, or the entire retina. In vivo electroretinography and transretinal recordings revealed normal cone photoresponses in all RDH10-deficient mouse lines. Notably, their cone-driven dark adaptation both in vivo and in isolated retina was unaffected, indicating that RDH10 is not required for the function of the retina visual cycle. We also generated transgenic mice expressing RDH10 ectopically in rod cells. However, rod dark adaptation was unaffected by the expression of RDH10 and transgenic rods were unable to use cis-retinol for pigment regeneration. We conclude that RDH10 is not the dominant retina 11-cis-RDH, leaving its primary function in the retina unknown.
Project description:We used microarrays to examine the temporal transcriptome changes of vitamin a deficient rats testes replenished with retinol 20-day old rats were put on a vitamin A deficient diet, after nine weeks the animals were treated with retinol for 0-(VAD), 4-, 8-, 24-hr to determine the global transcriptome changes induced by retinol replenishment of the vitmain A deficient testis
Project description:In this study, we identify disordered cardiac retinol metabolism in type 2 diabetic male mice and patients characterized by retinol overload, all-trans retinoic acid deficiency. By supplementing type 2 diabetic male mice with retinol or all-trans retinoic acid, we demonstrate that both cardiac retinol overload and all-trans retinoic acid deficiency promote diabetic cardiomyopathy. Mechanistically, by constructing cardiomyocyte-specific conditional retinol dehydrogenase 10-knockout male mice and overexpressing retinol dehydrogenase 10 in male type 2 diabetic mice via adeno-associated virus, we verify that the reduction in cardiac retinol dehydrogenase 10 is the initiating factor for cardiac retinol metabolism disorder and results in diabetic cardiomyopathy. Therefore, we suggest that the reduction of cardiac retinol dehydrogenase 10 and its mediated disorder of cardiac retinol metabolism is a new mechanism underlying diabetic cardiomyopathy.
Project description:The circadian clock has been found to be associated with various diseases. We showed that 5/6 nephrectomy (5/6Nx) Clk/Clk mice, which show mutation in the gene encoding circadian locomotor output cycles (Clock) do not show aggravation of renal fibrosis because transforming growth factor-1 (Tgf-1) expression is not increased. In wild-type 5/6Nx kidneys, we found that retinoid, a metabolite of retinol, led to alteration of the expresion 24-h rhythm of Clock expression. Renal Tgf- 1 expression is activated by Clock and further aggravates renal dysfunction by causing fibrosis. We also showed that, in 5/6Nx mice fed a retinol-free diet, renal fibrosis and apoptosis are reduced, leading to a marked improvement in serum creatinine levels. Moreover, our study identified hepatic Cyp3a11 and Cyp26a1 as key retinol metabolism-related genes whose expression decreased in 5/6Nx mice. Our data indicated that the negative chain reaction of metabolic clock alteration in between the kidney and liver aggravates renal dysfunction. Differential gene expression between retinol (-) feeding and clock mutant in 5/6 nephrectomized mouse was measured on the kidney at 8 weeks after operation. Four-week-old male ICR mice (Charles River Japan, Inc., Yokohama, Japan) were housed in a light-controlled room (lights on from Zeitgeber time [ZT] 0 to ZT12) at 24 ± 1°C and 60 ± 10% humidity, with food and water available ad libitum. Mice were synchronized to the lighting conditions for 2 weeks before surgery. Male ICR mice (5 weeks old) were purchased from Charles River Japan, Inc. (Kanagawa, Japan). Clock mutant mice (C57BL/6J-ClockmlJt/J) were purchased from The Jackson Laboratory (Bar Harbor, ME, USA). We placed them in the ICR genetic background to enhance breeding robustness and care of the young. These mice were backcrossed using a Jcl:ICR background for more than eight generations. We prepared mouse models of CRF by 5/6Nx operation (Ope) under sodium pentobarbital (40 mg/kg, i.p.) or diethyl ether anesthesia. 5/6Nx was performed in two stages. In the first surgical procedure (at 6 weeks of age), two-thirds of the left kidney was removed by cutting off both poles. Seven days later, the right kidney was completely removed. After the operation, mice were housed for 8 weeks (until they were 16 weeks old) in order to achieve CRF. Sham-operated (Sham) mice were subjected to laparotomy on the same days as the procedure in the 5/6Nx mice. This method was also used for treating Clk/Clk mice. Retinol-free food (A minus) was purchased form KBT ORIENTAL CO., LTD. To investigate the influences of retinol-free feeding on kidney, mice were fed from the fourth week to the eighth week after an operation.
Project description:The circadian clock has been found to be associated with various diseases. We showed that 5/6 nephrectomy (5/6Nx) Clk/Clk mice, which show mutation in the gene encoding circadian locomotor output cycles (Clock) do not show aggravation of renal fibrosis because transforming growth factor-1 (Tgf-1) expression is not increased. In wild-type 5/6Nx kidneys, we found that retinoid, a metabolite of retinol, led to alteration of the expresion 24-h rhythm of Clock expression. Renal Tgf- 1 expression is activated by Clock and further aggravates renal dysfunction by causing fibrosis. We also showed that, in 5/6Nx mice fed a retinol-free diet, renal fibrosis and apoptosis are reduced, leading to a marked improvement in serum creatinine levels. Moreover, our study identified hepatic Cyp3a11 and Cyp26a1 as key retinol metabolism-related genes whose expression decreased in 5/6Nx mice. Our data indicated that the negative chain reaction of metabolic clock alteration in between the kidney and liver aggravates renal dysfunction.