The Combination of High-Fat Diet and Oral Marijuana Promotes the Development of Fibrosis in the Mouse Corpora Cavernosa.

Introduction: The link between cannabis use and erectile dysfunction remains unclear. Moreover, the effect of cannabis in tandem with current Western dietary habits is an area in male sexual health that has yet to be explored. This study seeks to investigate the impact of diet and cannabis on penile health in an animal model.

Prevention of Osteoporosis in the Ovariectomized Rat by Oral Administration of a Nutraceutical Combination That Stimulates Nitric Oxide Production.

Osteoporosis represents an imbalance between bone formation and bone resorption. As a result of low estrogen levels, it is markedly prevalent during menopause, thus making such patients susceptible to fractures. Both bone formation and resorption are modulated by nitric oxide (NO).

Exogenous l-ARGININE does not stimulate production OF NO or cGMP within the rat corporal smooth muscle cells in culture.

Background And Aim: Nitric oxide (NO) is the intracellular chemical responsible for initiating a penile erection. Despite conflicting clinical data, it continues to be publicized and promoted that orally administered l-arginine, the putative substrate for NO, enhances the erectile response presumably by stimulating NO production by the corporal tissues resulting in an increase in cGMP production. To shed light on this issue, an in vitro study was conducted to explore the effect of direct exogenous administration of l-arginine as well as its precursor and metabolite, l-citrulline, on the NO-cGMP pathway within the cavernosal smooth muscle (CSM) cell.

Effect of ginger, Paullinia cupana, muira puama and l- citrulline, singly or in combination, on modulation of the inducible nitric oxide- NO-cGMP pathway in rat penile smooth muscle cells.

Introduction: COMP-4 is a natural compound-based dietary supplement consisting of the combination of ginger, Paullinia cupana, muira puama and l-citrulline, which when given long-term has been shown in the aged rat to a) upregulate iNOS in the penile smooth muscle cells (SMC), b) reverse the corporal SMC apoptosis and fibrosis associated with corporal veno-occlusive dysfunction (CVOD), and c) improve resulting erectile function. To elucidate the mechanism of how COMP-4 and its individual components modulate the iNOS-cGMP pathway, an in vitro study was conducted using a rat corporal primary SMC culture to determine its effect on NOS, soluble guanylate cyclase (sGC), cGMP and the phosphodiesterase 5 enzyme (PDE5).

Materials And Methods: Primary SMC cultures using the explant technique were initiated by cutting small pieces of corporal tissue from 8 week old Sprague-Dawley rats.

Vitamin D induces myogenic differentiation in skeletal muscle derived stem cells.

Skeletal muscle wasting is a serious disorder associated with health conditions such as aging, chronic kidney disease and AIDS. Vitamin D is most widely recognized for its regulation of calcium and phosphate homeostasis in relation to bone development and maintenance. Recently, vitamin D supplementation has been shown to improve muscle performance and reduce the risk of falls in vitamin D deficient older adults.

Vitamin D and Cardiac Differentiation.

Calcitriol (1,25-dihydroxycholecalciferol or 1,25-D3) is the hormonally active metabolite of vitamin D. Experimental studies of vitamin D receptors and 1,25-D3 establish calcitriol to be a critical regulator of the structure and function of the heart. Clinical studies link vitamin D deficiency with cardiovascular disease (CVD).

Treatment with a combination of ginger, L-citrulline, muira puama and Paullinia cupana can reverse the progression of corporal smooth muscle loss, fibrosis and veno-occlusive dysfunction in the aging rat.

Aims: Aging associated erectile dysfunction is characterized within the corpora by a progressive apoptosis of the smooth muscle cells and their replacement by collagen. Nitric oxide from iNOS has been shown to inhibit these histological changes in the corpora while PDE5 inhibitors as well as certain nutraceuticals such as ginger, paullinia cupana, muira puama and L-citrulline are known to enhance the effects of NO. We evaluated whether the daily oral administration for 2 months with a combination of ginger, paullinia cupana, muira puama and L-citrulline (COMP-4) can effectively delay the ongoing corporal fibrosis, smooth muscle cell apoptosis and cavernosal veno-occlusive dysfunction (CVOD) seen in middle aged rats similar to that seen with tadalafil.

Sildenafil attenuates inflammation and oxidative stress in pelvic ganglia neurons after bilateral cavernosal nerve damage.

Erectile dysfunction is a common complication for patients undergoing surgeries for prostate, bladder, and colorectal cancers, due to damage of the nerves associated with the major pelvic ganglia (MPG). Functional re-innervation of target organs depends on the capacity of the neurons to survive and switch towards a regenerative phenotype. PDE5 inhibitors (PDE5i) have been successfully used in promoting the recovery of erectile function after cavernosal nerve damage (BCNR) by up-regulating the expression of neurotrophic factors in MPG.

1,25-Vitamin D3 promotes cardiac differentiation through modulation of the WNT signaling pathway.

Cardiovascular disease (CVD) remains the leading cause of death worldwide. Low levels of vitamin D are associated with high risk of myocardial infarction, even after controlling for factors associated with coronary artery disease. A growing body of evidence indicates that vitamin D plays an important role in CVD-related signaling pathways.

1,25(OH)(2)vitamin D(3) enhances myogenic differentiation by modulating the expression of key angiogenic growth factors and angiogenic inhibitors in C(2)C(12) skeletal muscle cells.

Vitamin D is mostly recognized for its regulation of calcium homeostasis in relation to the intestine, kidney, and bone. Although clinical studies have linked vitamin D with increased muscle function and strength, little is known of its underlying molecular mechanism. We recently demonstrated that 1,25-D3 exerts a direct pro-myogenic effect on skeletal muscle cells; this has provoked our investigation of 1,25-D's effect on angiogenesis, a vital process for new capillary development and tissue repair.

Sildenafil promotes neuroprotection of the pelvic ganglia neurones after bilateral cavernosal nerve resection in the rat.

Objective: To determine the gene expression profile of pelvic ganglia neurones after bilateral cavernosal nerve resection (BCNR) and subsequent treatment with sildenafil in relation to neurotrophic-related pathways.

Materials And Methods: Fisher rats aged 5 months were subjected to BCNR or sham operation and treated with or without sildenafil (20 mg/kg body-weight in drinking water) for 7 days. Total RNA isolated from pelvic ganglia was subjected to reverse transcription and then to quantitative reverse transcriptase-polymerase chain reaction (PCR) with the RAT-neurotrophic array.

Vitamin D and cardiovascular disease: potential role in health disparities.

Cardiovascular disease (CVD), which includes coronary artery disease and stroke, is the leading cause of mortality in the nation. Excess CVD morbidity and premature mortality in the African American community is one of the most striking examples of racial/ ethnic disparities in health outcomes. African Americans also suffer from increased rates of hypovitaminosis D, which has emerged as an independent risk factor for all-cause and cardiovascular mortality.

1,25(OH)2vitamin D3 stimulates myogenic differentiation by inhibiting cell proliferation and modulating the expression of promyogenic growth factors and myostatin in C2C12 skeletal muscle cells.

Skeletal muscle wasting is an important public health problem associated with aging, chronic disease, cancer, kidney dialysis, and HIV/AIDS. 1,25-Dihydroxyvitamin D (1,25-D3), the active form of vitamin D, is widely recognized for its regulation of calcium and phosphate homeostasis in relation to bone development and maintenance and for its calcemic effects on target organs, such as intestine, kidney, and parathyroid glands. Emerging evidence has shown that vitamin D administration improves muscle performance and reduces falls in vitamin D-deficient older adults.

Sildenafil promotes smooth muscle preservation and ameliorates fibrosis through modulation of extracellular matrix and tissue growth factor gene expression after bilateral cavernosal nerve resection in the rat.

Introduction: It has been shown that phosphodiesterase type 5 (PDE5) inhibitors preserve smooth muscle (SM) content and ameliorate the fibrotic degeneration normally seen in the corpora cavernosa after bilateral cavernosal nerve resection (BCNR). However, the downstream mechanisms by which these drugs protect the corpora cavernosa remain poorly understood.

Aim: To provide insight into the mechanism, we aimed to determine the gene expression profile of angiogenesis-related pathways within the penile tissue after BCNR with or without continuous sildenafil (SIL) treatment.

1,25(OH)2vitamin D3 inhibits cell proliferation by promoting cell cycle arrest without inducing apoptosis and modifies cell morphology of mesenchymal multipotent cells.

The vitamin D receptor (VDR) and its ligand 1,25D play an important role in regulating cell growth and cell fate. We examined the effect of 1,25D on cell morphology, cell proliferation, cell cycle progression and apoptosis on mesenchymal multipotent cells. Multipotent cells were treated with and without 1,25D in a time- and dose-dependent manner.

Vitamin D and the cardiovascular system.

Several epidemiologic and clinical studies have suggested that there is a strong association between hypovitaminosis D and cardiovascular disease (CVD). Hypovitaminosis D was reported as a risk factor for increased cardiovascular events among 1739 adult participants in the Framingham Offspring Study. Analysis of more than 13,000 adults in the Third National Health and Nutrition Examination Survey (NHANES III) showed that even though hypovitaminosis D is associated with an increased prevalence of CVD risk factors, its association with all-cause mortality is independent of these risk factors.

Vitamin D reduces the expression of collagen and key profibrotic factors by inducing an antifibrotic phenotype in mesenchymal multipotent cells.

Hypovitaminosis D is an important public health problem. Serum 25-hydroxyvitamin D (25-OHD) is now recognized as an independent predictor for cardiovascular and related diseases (CVD) as well as other chronic medical conditions. However, the biologic pathways through which these effects are mediated remain poorly understood.

Regulation of myogenic differentiation by androgens: cross talk between androgen receptor/ beta-catenin and follistatin/transforming growth factor-beta signaling pathways.

Androgens are important regulators of body composition and promote myogenic differentiation and inhibit adipogenesis of mesenchymal, multipotent cells. Here, we investigated the mechanisms by which androgens induce myogenic differentiation of mesenchymal multipotent cells. Incubation of mesenchymal multipotent C3H 10T1/2 cells with testosterone and dihydrotestosterone promoted nuclear translocation of androgen receptor (AR)/beta-catenin complex and physical interaction of AR, beta-catenin, and T-cell factor-4 (TCF-4).

Myostatin promotes a fibrotic phenotypic switch in multipotent C3H 10T1/2 cells without affecting their differentiation into myofibroblasts.

Tissue fibrosis, the excessive deposition of collagen/extracellular matrix combined with the reduction of the cell compartment, defines fibroproliferative diseases, a major cause of death and a public health burden. Key cellular processes in fibrosis include the generation of myofibroblasts from progenitor cells, and the activation or switch of already differentiated cells to a fibrotic synthetic phenotype. Myostatin, a negative regulator of skeletal muscle mass, is postulated to be involved in muscle fibrosis.

Alterations in myostatin expression are associated with changes in cardiac left ventricular mass but not ejection fraction in the mouse.

Myostatin (Mst) is a negative regulator of skeletal muscle in humans and animals. It is moderately expressed in the heart of sheep and cattle, increasing considerably after infarction. Genetic blockade of Mst expression increases cardiomyocyte growth.

Myostatin short interfering hairpin RNA gene transfer increases skeletal muscle mass.

Background: Myostatin negatively regulates skeletal muscle growth. Myostatin knockout mice exhibit muscle hypertrophy and decreased interstitial fibrosis. We investigated whether a plasmid expressing a short hairpin interfering RNA (shRNA) against myostatin and transduced using electroporation would increase local skeletal muscle mass.

Testosterone inhibits adipogenic differentiation in 3T3-L1 cells: nuclear translocation of androgen receptor complex with beta-catenin and T-cell factor 4 may bypass canonical Wnt signaling to down-regulate adipogenic transcription factors.

Testosterone supplementation in men decreases fat mass; however, the mechanisms by which it inhibits fat mass are unknown. We hypothesized that testosterone inhibits adipogenic differentiation of preadipocytes by activation of androgen receptor (AR)/beta-catenin interaction and subsequent translocation of this complex to the nucleus thereby bypassing canonical Wnt signaling. We tested this hypothesis in 3T3-L1 cells that differentiate to form fat cells in adipogenic medium.

Myostatin inhibits myogenesis and promotes adipogenesis in C3H 10T(1/2) mesenchymal multipotent cells.

Inactivating mutations of the mammalian myostatin gene are associated with increased muscle mass and decreased fat mass; conversely, myostatin transgenic mice that overexpress myostatin in the skeletal muscle have decreased muscle mass and increased fat mass. We investigated the effects of recombinant myostatin protein and antimyostatin antibody on myogenic and adipogenic differentiation of mesenchymal multipotent cells. Accordingly, 10T(1/2) cells were incubated with 5'-azacytidine for 3 d to induce differentiation and then treated with a recombinant protein for myostatin (Mst) carboxy terminal 113 amino acids or a polyclonal anti-Mst antibody for 3, 7, and 14 d.

Androgens stimulate myogenic differentiation and inhibit adipogenesis in C3H 10T1/2 pluripotent cells through an androgen receptor-mediated pathway.

Testosterone supplementation increases skeletal muscle mass and decreases fat mass; however, the underlying mechanisms are unknown. We hypothesized that testosterone regulates body composition by promoting the commitment of mesenchymal pluripotent cells into myogenic lineage and inhibiting their differentiation into adipogenic lineage. Mouse C3H 10T1/2 pluripotent cells were treated with testosterone (0-300 nM) or dihydrotestosterone (DHT, 0-30 nM) for 0-14 d, and myogenic conversion was evaluated by immunocytochemical staining for early (MyoD) and late (myosin heavy chain II; MHC) myogenic markers and by measurements of MyoD and MHC mRNA and protein.

Lower skeletal muscle mass in male transgenic mice with muscle-specific overexpression of myostatin.

Mutations in the myostatin gene are associated with hypermuscularity, suggesting that myostatin inhibits skeletal muscle growth. We postulated that increased tissue-specific expression of myostatin protein in skeletal muscle would induce muscle loss. To investigate this hypothesis, we generated transgenic mice that overexpress myostatin protein selectively in the skeletal muscle, with or without ancillary expression in the heart, utilizing cDNA constructs in which a wild-type (MCK/Mst) or mutated muscle creatine kinase (MCK-3E/Mst) promoter was placed upstream of mouse myostatin cDNA.