The ubiquitous existence of microplastics and nanoplastics raises concerns about their potential impact on the human reproductive system. Limited data exists on microplastics within the human reproductive system and their potential consequences on sperm quality. Our objectives were to quantify and characterize the prevalence and composition of microplastics within both canine and human testes and investigate potential associations with the sperm count, and weights of testis and epididymis.
View Article and Find Full Text PDFBisphenol A is an endocrine disruptor that has been shown to have testicular toxicity in animal models. Its structural analog, including bisphenol S (BPS), bisphenol AF (BPAF), and tetrabromobisphenol A (TBBPA) have been introduced to the market as BPA alternatives. Previously, we developed high-content analysis (HCA) assays and applied machine learning to compare the testicular toxicity of BPA and its analogs in spermatogonial cells and testicular cell co-culture models.
View Article and Find Full Text PDFThe goal of this study is to examine bisphenol AF (BPAF)-induced multinucleation (MNC) in comparison with dibutyl phthalate (DBP), known to induce MNC in mouse gonocytes in vivo. We performed image-based single-cell high content analysis (HCA) in the mouse spermatogonia C18-4 cells treated with various concentrations of BPAF and DBP. BPAF as low as 5 µM was cytotoxic and resulted in 40% cell death of the C18-4 cells after 72 h.
View Article and Find Full Text PDFHuman obesity has become a global health epidemic, with few safe and effective pharmacological therapies currently available. The systemic loss of ovarian estradiol (E2) in women after menopause greatly increases the risk of obesity and metabolic dysfunction, revealing the critical role of E2 in this setting. The salutary effects of E2 are traditionally attributed to the classical estrogen receptors ERα and ERβ, with the contribution of the G protein-coupled estrogen receptor (GPER) still largely unknown.
View Article and Find Full Text PDFIn this study, we investigated if subunit displacement and/or alterations in proteasome biosynthesis are responsible for the changes in the levels of constitutive proteasomes (c-20S), immunoproteasomes (i-20S) and the activators PA28 and PA700 in neurons and astrocytes cultured with a cytokine mixture (IFN-γ/TNF-α/IL-1β). Exposure of both cell types to cytokines for 24 h increases mRNA and protein expression of the i-20S-specific subunit β5i and PA28α/β, and leads to a decline in the amount of the c-20S-specific subunit β5. Since β5 mRNA levels are unchanged by the cytokine treatment, it is fair to conclude that displacement of constitutive β-subunits with inducible β5i subunits is likely the mechanism underlying the decrease in c-20S.
View Article and Find Full Text PDFThe goal of this study was to determine if subunit displacement and/or alterations in proteasome biosynthesis could explain the changes observed in the levels of constitutive proteasomes (c-20S) and immunoproteasomes (i-20S) in the spinal cords of mice with experimental autoimmune encephalomyelitis (EAE). To this end, EAE was induced in C57BL/6 mice by immunization with MOG peptide. Spinal cords were collected at different times during the disease course and used for western blotting, RNA analysis, and immunohistochemistry.
View Article and Find Full Text PDFGlutathione peroxidase 4 (GPx4) is the only enzyme capable of reducing toxic lipid hydroperoxides in biological membranes to the corresponding alcohols using glutathione as the electron donor. GPx4 is the major inhibitor of ferroptosis, a non-apoptotic and iron-dependent programmed cell death pathway, which has been shown to occur in various neurological disorders with severe oxidative stress. In this study, we investigate whether GPx4 expression is altered in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE).
View Article and Find Full Text PDFThe present study was designed to investigate the role of calpain and the proteasome in the removal of oxidized neuronal cytoskeletal proteins in myelin basic protein-induced experimental autoimmune encephalomyelitis (EAE). To this end, EAE rats received a single intrathecal injection of calpeptin or epoxomicin at the first sign of clinical disease. Forty-eight hours later, animals were sacrificed and lumbar spinal cord segments were dissected and used for biochemical analyses.
View Article and Find Full Text PDFThis study was conducted to further our understanding about the link between lipid peroxidation and protein carbonylation in rat brain slices incubated with the glutathione (GSH)-depletor diethyl maleate. Using this in vitro system of oxidative stress, we found that there is a significant lag between the appearance of carbonylated proteins and GSH depletion, which seems to be due to the removal of oxidized species early on in the incubation by the mitochondrial Lon protease. Upon acute GSH depletion, protein carbonyls accumulated mostly in mitochondria and to a lesser degree in other subcellular fractions that also contain high levels of polyunsaturated lipids.
View Article and Find Full Text PDFThis study investigates the possible mechanism(s) underlying glutathione (GSH) deficiency in the mouse spinal cord during the course of myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of multiple sclerosis. Using the classical enzymatic recycling method and a newly developed immunodot assay, we first demonstrated that total GSH levels (i.e.
View Article and Find Full Text PDFCoronary atherosclerosis and myocardial infarction in postmenopausal women have been linked to inflammation and reduced nitric oxide (NO) formation. Natural estrogen exerts protective effects on both processes, yet also displays uterotrophic activity. Here, we used genetic and pharmacologic approaches to investigate the role of the G protein-coupled estrogen receptor (GPER) in atherosclerosis.
View Article and Find Full Text PDFUnlabelled: The role of 17β-estradiol (E2) in breast cancer development and tumor growth has traditionally been attributed exclusively to the activation of estrogen receptor-α (ERα). Although targeted inhibition of ERα is a successful approach for patients with ERα(+) breast cancer, many patients fail to respond or become resistant to anti-estrogen therapy. The discovery of the G protein-coupled estrogen receptor (GPER) suggested an additional mechanism through which E2 could exert its effects in breast cancer.
View Article and Find Full Text PDFEndometrial carcinoma is the most common cancer of the female reproductive tract. GPER/GPR30 is a 7-transmembrane spanning G protein-coupled receptor that has been identified as the third estrogen receptor, in addition to ERα and ERβ. High GPER expression is predictive of poor survival in endometrial and ovarian cancer, but despite this, the estrogen-mediated signaling pathways and specific estrogen receptors involved in endometrial cancer remain unclear.
View Article and Find Full Text PDFEstrogen is an important regulator of metabolic syndrome, a collection of abnormalities including obesity, insulin resistance/glucose intolerance, hypertension, dyslipidemia, and inflammation, which together lead to increased risk of cardiovascular disease and diabetes. The role of the G protein-coupled estrogen receptor (GPER/GPR30), particularly in males, in these pathologies remains unclear. We therefore sought to determine whether loss of GPER contributes to aspects of metabolic syndrome in male mice.
View Article and Find Full Text PDFBackground: For reasons that remain unclear, whether type 5 adenylyl cyclase (AC5), 1 of 2 major AC isoforms in heart, is protective or deleterious in response to cardiac stress is controversial. To reconcile this controversy we examined the cardiomyopathy induced by chronic isoproterenol in AC5 transgenic (Tg) mice and the signaling mechanisms involved.
Methods And Results: Chronic isoproterenol increased oxidative stress and induced more severe cardiomyopathy in AC5 Tg, as left ventricular ejection fraction fell 1.
Previous studies have shown that the DNA repair component Metnase (SETMAR) mediates resistance to DNA damaging cancer chemotherapy. Metnase has a nuclease domain that shares homology with the Transposase family. We therefore virtually screened the tertiary Metnase structure against the 550,000 compound ChemDiv library to identify small molecules that might dock in the active site of the transposase nuclease domain of Metnase.
View Article and Find Full Text PDFEndogenous estrogens mediate protective effects in the cardiovascular system, affecting both endothelium-dependent and endothelium-independent mechanisms. Previous studies have suggested that nonselective estrogen receptor agonists such as endogenous estrogens inhibit endothelium-dependent vasoconstriction; however, the role of estrogen receptors in this response has not yet been clarified. This study investigated whether the intracellular transmembrane G protein-coupled estrogen receptor (GPER) regulates vascular reactivity in mice.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
November 2009
Adenylyl cyclase (AC) types 5 and 6 (AC5 and AC6) are the two major AC isoforms expressed in the mammalian heart that mediate signals from beta-adrenergic receptor stimulation. Because of the unavailability of isoform-specific antibodies, it is difficult to ascertain the expression levels of AC5 protein in the heart. Here we demonstrated the successful generation of an AC5 isoform-specific mouse monoclonal antibody and studied the expression of AC5 protein during cardiac development in different mammalian species.
View Article and Find Full Text PDFAttractin (ATRN) and Attractin-like 1 (ATRNL1) are highly similar type I transmembrane proteins. Atrn null mutant mice have a pleiotropic phenotype including dark fur, juvenile-onset spongiform neurodegeneration, hypomyelination, tremor, and reduced body weight and adiposity, implicating ATRN in numerous biological processes. Bioinformatic analysis indicated that Atrn and Atrnl1 arose from a common ancestral gene early in vertebrate evolution.
View Article and Find Full Text PDFOvarian follicle development is dependent on growth factors that stimulate cell proliferation and act as survival factors to prevent apoptosis of follicle cells. We examined the mechanism of the protective effect of IGF-I against Fas ligand-induced apoptosis of granulosa cells and its relationship to cell proliferation. IGF-I activated both the phosphoinositide 3'-OH kinase (PI3K) and the MAPK pathways.
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