Tissue-specific expression of steroidogenic enzymes allows the modulation of active steroid levels in a local manner. Thus, the measurement of local steroid concentrations, rather than the circulating levels, has been recognized as a more accurate indicator of the steroid action within a specific tissue. Adipose tissue, one of the largest endocrine tissues in the human body, has been established as an important site for steroid storage and metabolism.
View Article and Find Full Text PDFSteroidogenesis begins with cholesterol transfer into mitochondria through the transduceosome, a complex composed of cytosolic proteins that include steroidogenesis acute regulatory protein (STAR), 14-3-3 adaptor proteins, and the outer mitochondrial membrane proteins Translocator Protein (TSPO) and Voltage-Dependent Anion Channel (VDAC). TSPO is a drug- and cholesterol-binding protein found at particularly high levels in steroid synthesizing cells. Its aberrant expression has been linked to cancer, neurodegeneration, neuropsychiatric disorders and primary hypogonadism.
View Article and Find Full Text PDFReduced serum testosterone (T), or hypogonadism, is estimated to affect about 5 million American men, including both aging and young men. Low serum T has been linked to mood changes, worsening cognition, fatigue, depression, decreased lean body mass and bone mineral density, increased visceral fat, metabolic syndrome, decreased libido, and sexual dysfunction. Administering exogenous T, known as T-replacement therapy (TRT), reverses many of the symptoms of low T levels.
View Article and Find Full Text PDFDegarelix is a gonadrotropin-releasing hormone (GnRH) receptor (GnRHR) antagonist used in patients with prostate cancer who need androgen deprivation therapy. GnRHRs have been found in extra-pituitary tissues, including prostate, which may be affected by the GnRH and GnRH analogues used in therapy. The direct effect of degarelix on human prostate cell growth was evaluated.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
March 2015
Humans are continuously exposed to hundreds of man-made chemicals that pollute the environment in addition to multiple therapeutic drug treatments administered throughout life. Some of these chemicals, known as endocrine disruptors (EDs), mimic endogenous signals, thereby altering gene expression, influencing development, and promoting disease. Although EDs are eventually removed from the market or replaced with safer alternatives, new evidence suggests that early-life exposure leaves a fingerprint on the epigenome, which may increase the risk of disease later in life.
View Article and Find Full Text PDFLeydig cell testosterone (T) production is reduced with age, resulting in reduced serum T levels (hypogonadism). A number of cellular changes have been identified in the steroidogenic pathway of aged Leydig cells that are associated with reduced T formation, including reductions in luteinizing hormone (LH)-stimulated cAMP production, the cholesterol transport proteins steroidogenic acute regulatory (STAR) protein and translocator protein (TSPO), and downstream steroidogenic enzymes of the mitochondria and smooth endoplasmic reticulum. Many of the changes in steroid formation that characterize aged Leydig cells can be elicited by the experimental alteration of the redox environment of young cells, suggesting that changes in the intracellular redox balance may cause reduced T production.
View Article and Find Full Text PDFDi-2-ethylhexyl phthalate (DEHP) is an endocrine disruptor used in industry as an additive to polyvinyl chloride-based products. Pregnant dams were gavaged with oil, 1, 20, 50, or 300mg of DEHP/kg/day from gestational day 14 until birth in order to characterize the effects of DEHP in the adult female offspring. In utero exposure to DEHP resulted in reduced estrogen levels at proestrus.
View Article and Find Full Text PDFBackground: Proximal deletions in the 13q12.11 region are very rare. Much larger deletions including this region have been described and are associated with complex phenotypes of mental retardation, developmental delay and various others anomalies.
View Article and Find Full Text PDFThe translocator protein (TSPO), which was previously designated as the peripheral-type benzodiazepine receptor, is a 3.5 billion year-old evolutionarily conserved protein expressed by most Eukarya, Archae and Bacteria, but its organization and functions differ remarkably. By taking advantage of the genomic data available on TSPO, we focused on bacterial TSPO and attempted to define functions of TSPO in Pseudomonas via in silico approaches.
View Article and Find Full Text PDFLeydig cell steroidogenesis is a multistep process that takes place in the mitochondria and endoplasmic reticulum (ER). The physical association between these 2 organelles could facilitate both steroidogenesis substrate availability and mitochondrial product passage to steroidogenic enzymes in the ER, thus regulating the rate of steroid formation. Confocal microscopy, using antisera against organelle-specific antigens, and electron microscopy studies demonstrated that there is an increase in the number of mitochondria-ER contact sites in response to hormone treatment in MA-10 mouse tumor Leydig cells.
View Article and Find Full Text PDFExposure to environmental toxicants during fetal development alters gene expression and promotes disease later in life. Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used for the manufacturing of consumer products. Exposure to DEHP has been associated with obesity, asthma, and low T levels.
View Article and Find Full Text PDFObjective: Pain is one of the most undertreated medical complaints, with barriers to effective pain management lying in poor education of health professionals and misconceptions regarding patients in pain. The aim of this study was to assess whether an elective undergraduate course on chronic pain offered in Greek medical schools influences knowledge and attitudes of medical undergraduates about chronic pain and helps them clarify pain-related concepts.
Methods: An electronic questionnaire with 6 demographic and 21 pain-related items was uploaded on SurveyMonkey.
Mitochondria are home to many cellular processes, including oxidative phosphorylation and fatty acid metabolism, and in steroid-synthesizing cells, they are involved in cholesterol import and metabolism, which is the initiating step in steroidogenesis. The formation of macromolecular protein complexes aids in the regulation and efficiency of these mitochondrial functions, though because of their dynamic nature, they are hard to identify. To overcome this problem, we used Blue-Native PAGE with whole-gel mass spectrometry on isolated mitochondria from control and hormone-treated MA-10 mouse tumor Leydig cells.
View Article and Find Full Text PDFObjective: Pre- or early-pregnancy obesity carries significant health implications. This retrospective cohort study investigates the association between pre- or early-pregnancy body mass index (BMI) and the risk of fetal and neonatal death in pregnancies implicated by obesity in a Mediterranean country.
Study Design: Data on pregnancies delivered during 2003-2008 at a University hospital was linked to data from regional registry.
Background: Epigenetics is the study of gene expression changes that are not caused by changes in the deoxyribonucleic acid (DNA) sequence. DNA methylation is an epigenetic mark occurring in C-phosphate-G sites (CpGs) that leads to local or regional gene expression changes. Reduced-representation bisulfite sequencing (RRBS) is a technique that is used to ascertain the DNA methylation of millions of CpGs at single-nucleotide resolution.
View Article and Find Full Text PDFThe 14-3-3 protein family comprises adaptors and scaffolds that regulate intracellular signaling pathways. The 14-3-3γ isoform is a negative regulator of steroidogenesis that is hormonally induced and transiently functions at the initiation of steroidogenesis by delaying maximal steroidogenesis in MA-10 mouse tumor Leydig cells. Treatment of MA-10 cells with the cAMP analog 8-bromo-cAMP (8-Br-cAMP), which stimulates steroidogenesis, triggers the interaction of 14-3-3γ with the steroidogenic acute regulatory protein (STAR) in the cytosol, limiting STAR activity to basal levels.
View Article and Find Full Text PDFIntroduction: Endometriosis affects 3 to 10 percent of women of reproductive age. Most of the time it involves the pelvis; however, sites of endometriosis have been reported almost anywhere in the body. Appendiceal and primary umbilical endometriosis are considered rare loci, making accurate diagnosis elusive.
View Article and Find Full Text PDFCa(2+)-induced permeability transition pore (mPTP) opening in isolated rat brain mitochondria is promoted through targeting of connexin43. After a threshold Ca(2+) load, mitochondrial membrane potential drops and efflux of accumulated Ca(2+) from the mitochondrial matrix occurs, indicating the mPTP opening. Specific antibodies were used to assess the role of the translocator protein (18kDa; TSPO) and connexin43 in swelling of isolated rat liver and brain mitochondria induced by carbenoxolone and the endogenous TSPO ligand protoporphyrin IX.
View Article and Find Full Text PDFLow testosterone (T), a major cause of male hypogonadism and infertility, is linked to mood changes, fatigue, osteoporosis, reduced bone-mass index, and aging. The treatment of choice, T replacement therapy, has been linked with increased risk for prostate cancer and luteinizing hormone (LH) suppression, and shown to lead to infertility, cardiovascular diseases, and obesity. Alternate methods to induce T with lower side effects are desirable.
View Article and Find Full Text PDFSteroid hormones, bioactive oxysterols and bile acids are all derived from the biological metabolism of lipid cholesterol. The enzymatic pathways generating these compounds have been an area of intense research for almost a century, as cholesterol and its metabolites have substantial impacts on human health. Owing to its high degree of hydrophobicity and the chemical properties that it confers to biological membranes, the distribution of cholesterol in cells is tightly controlled, with subcellular organelles exhibiting highly divergent levels of cholesterol.
View Article and Find Full Text PDFThe commonest sights of appearance of condylomata acuminata are in the genital and anal regions. Herein we present two cases of condylomata within perianal fistulae tracts, resulting in recurrence in one case and a malignant-like tumour in the second. To our knowledge, these are the first cases reported in the literature.
View Article and Find Full Text PDFBackground: Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer used to increase the flexibility of polyvinyl chloride. DEHP and its active metabolite mono-(2-ethylhexyl) phthalate are detected in many biological fluids during fetal and postnatal life. In rodent models, in utero DEHP exposure has been shown to alter sexual organ development, decrease testosterone and aldosterone production, increase body and epididymal adipose tissue weight, and raise serum lipids and glucose levels in male offspring.
View Article and Find Full Text PDFThe plasticizer di-(2-ethylhexyl) phthalate (DEHP) is used to add flexibility to polyvinylchloride polymers and as a component of numerous consumer and medical products. DEHP and its metabolites have been detected in amniotic fluid and umbilical cord blood, suggesting fetal exposure. In the present study, we used an in utero exposure model in which pregnant rat dams were exposed to 1- to 300-mg DEHP/kg·d from gestational day 14 until birth.
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