Project description:Genistein is one of the flabonoids which is included in high concentration in soy and has a high estrogenic activity. Beneficial effects of estrogen or hormone replacement therapy (HRT) on muscle mass or muscle atrophy have been demonstrated. We investigated the preventive effects and underlying mechanisms of genistein intake on denervation-induced muscle atrophy. Genistein intake significantly suppressed the loss of soleus muscle weight and the denervation-induced up-regulations of FOXO1 protein. The results of a DNA microarray showed that the estrogen receptor (ER) target genes are changed by genistein intake. Genistein suppressed the soleus muscle atrophy, and it was attenuated under the ER antagonist treatment. The administration of an ERα agonist suppressed the denervation-induced muscle atrophy and up-regulation of Atrogin1 gene expression, but the ERβ agonist had no effect.
Project description:We used microarrays to detail the global transcriptional response mediated by ERalpha or ERbeta to the phytoestrogen genistein in the MCF-7 human breast cancer cell model. Experiment Overall Design: MCF-7 human breast cancer cells expressing endogenouse Estrogen Receptor Alpha (ERalpha) were infected with adenovirus carrying either estrogen receptor beta (AdERb) or no insert (Ad) at multiplicity of infection (moi) of 20. Cells were then treated with either vehicle control (veh), 6nM 17beta-estradiol (E2), 6nM genistein (LG), 300nM genistein (HG), 300nM S-Equol (EQ), HG+3uM ICI182,780 (IG), EQ+3uM ICI 182,780(IE) for a additional periods of 4h or 24hr before RNA extraction and hybridization on Affymetrix microarrays. We sought to determine if genistein and S-Equol, phytoestrogens selective for the ERbeta can elicit transcriptional response distinctive from those mediated by the ERalpha.
Project description:Local biosynthesis of estrogen in lower abdominal skeletal muscle tissue leads to estrogen receptor-α-mediated fibrosis, muscle atrophy, and inguinal hernia. We used microarrays to detail the gene expression after aromatase expression in lower abdominal muscle tissue and identify distinct classes of up-regulated or down-regulated genes.
Project description:Muscle atrophy is associated with aging (sarcopenia) and chronic unloading (such as bed confinement and immobilization with casts), as well as various pathological conditions such as type 1 diabetes and nerve injury (denervation). C57BL/6 mice (7 weeks old, male) were denervated. After 14 days, skeletal muscle was collected and RNA extracted. Expression of Dnmt3a was reduced while expression of Gdf5 was increased by denervation.
Project description:Skeletal muscle exhibits remarkably plasticity under both physiological and pathological conditions. We used adult mice with sciatic denervation as model of muscle atrophy. SnRNA-seq was performed to generate single-nucleus transcriptome profiles of gastrocnemius from normal and denervation mice. Our results define the myonuclear transition, metabolic remodeling and gene regulation networks associated with muscle atrophy induced by denervation and illustrated the molecular basis of heterogeneity and plasticity of muscle cells in response to muscle atrophy, thus providing a resource for exploring molecular mechanisms leading to muscle atrophy
Project description:<p>Environmental exposure to xenoestrogens, i.e., chemicals that imitate the hormone 17β-estradiol, has the potential to influence hormone homeostasis and action. Detailed knowledge of xenobiotic biotransformation processes in cell models is key when transferring knowledge learned from <em>in vitro</em> models to <em>in vivo</em> relevance. This study elucidated the metabolism of two naturally-occurring phyto- and myco-estrogens; namely genistein and zearalenone, in an estrogen receptor positive breast cancer cell line (MCF-7) with the aid of stable isotope-assisted metabolomics and the bioinformatic tool MetExtract II. Metabolism was studied in a time course experiment after 2, 6 and 24 h incubation. Twelve and six biotransformation products of zearalenone and genistein were detected, respectively, clearly demonstrating the abundant xenobiotic biotransformation capability of the cells. Zearalenone underwent extensive phase-I metabolism resulting in α-zearalenol (α-ZEL), a molecule known to possess a significantly higher estrogenicity, and several phase-II metabolites (sulfo- and glyco-conjugates) of the native compound and the major phase I metabolite α-ZEL. Moreover, potential adducts of zearalenone with a vitamin and several hydroxylated metabolites were annotated. Genistein metabolism resulted in sulfation, combined sulfation and hydroxylation, acetylation, glucuronidation and unexpectedly adduct formation with pentose- and hexose-sugars. Kinetics of metabolite formation and subsequent excretion into the extracellular medium revealed a time-dependent increase in most biotransformation products. The untargeted elucidation of biotransformation products formed during cell culture experiments enables an improved and more meaningful interpretation of toxicological assays and has the potential to identify unexpected or unknown metabolites.</p>
Project description:We report that the phytoestrogen genistein acts as a tissue-specific androgen receptor modulator in mouse using a novel androgen reporter mouse line and gene expression profiling. Genistein is a partial androgen agonist/antagonist in prostate, brain, and testis but not in skeletal muscle or lung. Gene expression profiling has been done from prostates of intact and castrated male mice treated with genistein or vehicle. Gene expression profiling was also done from prostates of estradiol-treated intact male mice.
Project description:The innervation of skeletal myofibers exerts a crucial influence on the maintenance of muscle tone and normal operation, but little is known concerning atrophy and its underlying mechanisms in denervated muscle to date. Here, we reported that activated NOD-like receptor protein 3 (NLRP3) inflammasome with pyroptotic cell death occurred in denervated gastrocnemius in the mouse model of sciatic denervation. This damage causes interleukin 1 beta (IL-1β) release,facilitating the ubiquitin proteasome system (UPS) activation, which was responsible for muscle proteolysis. Conversely, genetic knock-out of muscular NLRP3 inhibited the pyroptosis-associated protein expression and ameliorate muscle atrophy significantly. Meanwhile, co-treatment with shRNA-NLRP3, also remarkably attenuated NLRP3 inflammasome activator (NIA)-induced C2C12 myotube pyroptosis and atrophy. Interestingly, we also observed a correlation between NLRP3 inflammasome activation and muscular apoptosis possibly via caspase 1 mediation after denervation. This work for the first time elucidates on the roles and mechanisms of NLRP3 inflammasome in skeletal muscle atrophy during denervation and suggests the potential contribution to the pathogenesis of neuromuscular diseases.
Project description:Analysis of denervation induced regulation of muscle mass at gene expression level. The hypothesis tested in the present study was that the presence of MuRF1 contributes to the extent of gene expression changes observed in specific sets of genes during a challenge leading to muscle atrophy. Results provide important information on the response of triceps surae muscle to sciatic nerve resection (denervation), such as specific structural, metabolic, and neuromuscular junction associated genes, that may be influenced by MuRF1 during atrophy. Total RNA obtained from isolated triceps surae muscle subjected to 3 or 14 days post-denervation compared to nonsurgically treated littermate control muscles.