Sex-Dependent Effects of Dietary Genistein on Echocardiographic Profile and Cardiac GLUT4 Signaling in Mice

This study aimed to determine whether genistein diet resulted in changes in cardiac function, using echocardiography, and expression of key proteins involved in glucose uptake by the myocardium. Intact male and female C57BL/6J mice (aged 4–6 weeks) were fed either 600 mg genistein/kg diet (600 G) or 0 mg genistein/kg diet (0 G) for 4 weeks. Echocardiography data revealed sex-dependent differences in the absence of genistein: compared to females, hearts from males exhibited increased systolic left ventricle internal dimension (LVIDs), producing a decrease in function, expressed as fractional shortening (FS). Genistein diet also induced echocardiographic changes in function: in female hearts, 600G induced a 1.5-fold (P<0.05) increase in LVIDs, resulting in a significant decrease in FS and whole heart surface area when compared to controls (fed 0 G). Genistein diet increased cardiac GLUT4 protein expression in both males (1.51-fold, P<0.05) and females (1.76-fold, P<0.05). However, no effects on the expression of notable intracellular signaling glucose uptake-regulated proteins were observed. Our data indicate that consumption of genistein diet for 4 weeks induces echocardiographic changes in indices of systolic function in females and has beneficial effects on cardiac GLUT4 protein expression in both males and females

Effects of Exercise Training on Renal Carnitine Biosynthesis and Uptake in the High-Fat and High-Sugar-Fed Mouse

(1) Background: Diet-induced obesity inhibits hepatic carnitine biosynthesis. Herein, the effects of high-fat (HF) and high-sugar (HFHS) feeding and exercise training (ET) on renal carnitine biosynthesis and uptake were determined. (2) Methods: Male C57BL/6J mice were assigned to the following groups: lean control (standard chow), HFHS diet, and HFHS diet with ET. ET consisted of 150 min of treadmill running per week for 12 weeks. Protein levels of &gamma;-butyrobetaine hydroxylase (&gamma;-BBH) and organic cation transporter-2 (OCTN2) were measured as markers of biosynthesis and uptake, respectively. (3) Results: HFHS feeding induced an obese diabetic state with accompanying hypocarnitinemia, reflected by decreased free carnitine levels in plasma and kidney. This hypocarnitinemia was associated with decreased &gamma;-BBH (~30%) and increased OCTN2 levels (~50%). ET failed to improve the obesity and hyperglycemia, but improved insulin levels and prevented the hypocarnitinemia. ET increased protein levels of &gamma;-BBH, whereas levels of OCTN2 were decreased. Peroxisome proliferator-activated receptor-alpha content was not changed by the HFHS diet or ET. (4) Conclusions: Our results indicate that ET prevents the hypocarnitinemia induced by HFHS feeding by increasing carnitine biosynthesis in kidney. Increased expression of OCTN2 with HFHS feeding suggests that renal uptake was stimulated to prevent carnitine loss

Genistein treatment increases bone mass in obese, hyperglycemic mice

Richard M Michelin,1 Layla Al-Nakkash,2 Tom L Broderick,3 Jeffrey H Plochocki4 1Arizona College of Osteopathic Medicine, 2Department of Physiology, 3Laboratory of Diabetes and Exercise Metabolism, Department of Physiology, 4Department of Anatomy, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ, USA Background: Obesity and type 2 diabetes mellitus are associated with elevated risk of limb bone fracture. Incidences of these conditions are on the rise worldwide. Genistein, a phytoestrogen, has been shown by several studies to demonstrate bone-protective properties and may improve bone health in obese type 2 diabetics. Methods: In this study, we test the effects of genistein treatment on limb bone and growth plate cartilage histomorphometry in obese, hyperglycemic ob/ob mice. Six-week-old ob/ob mice were divided into control and genistein-treated groups. Genistein-treated mice were fed a diet containing 600 mg genistein/kg for a period of 4 weeks. Cross-sectional geometric and histomorphometric analyses were conducted on tibias. Results: Genistein-treated mice remained obese and hyperglycemic. However, histomorphometric comparisons show that genistein-treated mice have greater tibial midshaft diameters and ratios of cortical bone to total tissue area than the controls. Genistein-treated mice also exhibit decreased growth plate thickness of the proximal tibia. Conclusion: Our results indicate that genistein treatment affects bone of the tibial midshaft in the ob/ob mouse, independent of improvements in the hyperglycemic state and body weight. Keywords: obesity, hyperglycemia, genistein, ob/ob mice, bon

Genistein diet does not modify crypt morphology in the ob/ob mouse jejunum: a comparison of cryostat and clearing techniques

Noemy Sandoval-Skeet,1 Jason A Kaufman,2 Monica J Castro,2 Layla Al-Nakkash3 1Department of Biomedical Sciences, 2Department of Anatomy, 3Department of Physiology, Midwestern University, Glendale, AZ 85308, USA Introduction: Diabetes is commonly associated with gastrointestinal dysfunction. We have previously shown that transepithelial short circuit current, Isc (chloride secretion), is significantly reduced in the jejunum from ob/ob mice vs lean controls, and consumption of 600 mg genistein/kg of diet (600 G) for 4 weeks significantly rescues Isc. We aimed to evaluate whether morphological changes in the jejunal crypts contribute to the rescue of Isc. Methods: Male mice (ob/ob and lean controls) were fed either a genistein-free diet or genistein-containing diet (600 G). Comparisons of crypt morphology were made for crypt depth, length, and numbers of proliferative cells. Assessments of crypt measures using DAPI and 5-ethynyl-2&prime;-deoxyuridine (EdU) were performed using traditional cryostat sectioning and an innovative 3D optical clearing method. Results: We found that crypt length in the ob/ob genistein-fed group was significantly greater when measured with cleared tissue (85.19&plusmn;4.73 &micro;m, P&lt;0.05, n=8) compared to lengths measured with cryostat (65.42&plusmn;3.48 &micro;m, n=8). In addition, proliferative EdU+ counts were approximately fivefold greater with clearing, compared to counts obtained via single plane images from cryostat sections for all groups measured. The average length to EdU+ ratio was unchanged between groups. Conclusion: Thus, we conclude that genistein diet does not affect overall cellular proliferation or crypt morphology, other than for the modest increased crypt length measured via clearing in the ob/ob genistein group. The increase in crypt length is likely indicative of the greater accuracy of the 3D measures compared to single plane. Genistein diet-induced increases in the intestinal Isc are therefore likely not attributed to changes in intestinal crypt morphology. Keywords: genistein, intestine epithelia, jejunum, optical clearing, diabete

Leptin-deficient mice have altered three-dimensional growth plate histomorphometry

Abstract Background Leptin is an adipokine that regulates energy homeostasis and is also needed for normal bone growth and maintenance. Mutation in the lep gene, which characterizes the ob/ob mouse model, results in the development of obesity and type 2 diabetes mellitus, as well as reduced limb bone length and increased fracture risk. However, the relationship between limb bone length and growth plate cartilage structure in obese diabetic adolescents is incompletely understood. Here, we tested the hypothesis that leptin deficiency affects the microstructure of growth plate cartilage in juvenile ob/ob mice. Methods Tibial growth plate cartilage structure was compared between lean and obese, leptin-deficient (ob/ob) female mice aged 10 weeks. We used confocal laser scanning microscopy to assess 3D histological differences in Z stacks of growth plate cartilage at 0.2 µm intervals, 80–100 µm in depth. Histomorphometric comparisons were made between juvenile lean and ob/ob mice. Results We found obese mice have significantly reduced tibial length and growth plate height in comparison with lean mice (P < 0.05). Obese mice also have fewer chondrocyte columns in growth plate cartilage with reduced chondrocyte cell volumes relative to lean mice (P < 0.05). Conclusions These data help explicate the relationship between growth plate cartilage structure and bone health in obese diabetic juvenile mice. Our findings suggest obesity and diabetes may adversely affect growth plate cartilage structure