A5023640728- Sperm and Testicular Function
- Effects and risks of endocrine disrupting chemicals
- Estrogen and related hormone effects
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Reproductive Biology and Fertility
- Neuroscience and Neuropharmacology Research
- Adipose Tissue and Metabolism
- Proteoglycans and glycosaminoglycans research
- Reproductive System and Pregnancy
- Hormonal and reproductive studies
- Glycosylation and Glycoproteins Research
- Testicular diseases and treatments
- Carcinogens and Genotoxicity Assessment
- Renal and related cancers
- Drug Transport and Resistance Mechanisms
- Receptor Mechanisms and Signaling
- Ubiquitin and proteasome pathways
- Toxic Organic Pollutants Impact
- Birth, Development, and Health
- Mitochondrial Function and Pathology
- Hemoglobinopathies and Related Disorders
- Hormonal Regulation and Hypertension
- Physiological and biochemical adaptations
- Peroxisome Proliferator-Activated Receptors
- ATP Synthase and ATPases Research
University of Southern California
2018-2025
McGill University Health Centre
2012-2023
McGill University
2012-2023
Experimental Medicine and Biology Institute
2023
Hadassah Medical Center
2023
Bloomfield College
2023
Montreal General Hospital
2012-2015
United States Food and Drug Administration
2012
Georgetown University
2001-2011
Georgetown University Medical Center
2000-2011
The hyaluronan receptor belongs to the polymorphic family of CD44 glycoproteins, which have been implicated in a variety cellular functions including adhesion and collagen, binding lymphocytes high endothelial cells during extravasation, conferring metastatic potential carcinoma cells. Here, we demonstrate that also participates uptake degradation by both transformed fibroblasts (SV-3T3 cells) alveolar macrophages. These were incubated with isotopically labeled for various periods time,...
The present study was undertaken to determine the relationship between hyaluronate receptor and CD44 (H-CAM), cell-surface glycoproteins of similar molecular weights that have been implicated in cell adhesion. In initial experiments, a panel monoclonal antibodies directed against were tested for their ability cross react with receptor. These immunoprecipitated [3H]hyaluronate binding activity from detergent extracts both mouse human cells, indicating is identical CD44. addition, one these...
Hormone-induced steroid biosynthesis begins with the transfer of cholesterol from intracellular stores into mitochondria. Steroidogenic acute regulatory protein (StAR) and peripheral-type benzodiazepine receptor (PBR) have been implicated in this rate-determining step steroidogenesis. MA-10 mouse Leydig tumor cells were treated without oligodeoxynucleotides (ODNs) antisense to PBR StAR followed by treatment saturating concentrations human choriogonadotropin. Treatment ODNs but not missense...
Abstract To determine what factors regulate gonocyte proliferation in newborn rats, we first examined the expression of several signal transduction molecules by immunocytochemistry 3-day-old rat testis sections. We found that gonocytes specifically expressed ι and ζ isoforms protein kinase (PK) C (PKC) phosphatidylinositol 3-kinase (PI 3-K). Because both ζPKC PI 3-K have been shown to play a role platelet-derived growth factor (PDGF)-induced cell proliferation, effects PDGF on gonocytes. For...
We examined the effects of fetal exposure to a wide range di-(2-ethylhexyl) phthalate (DEHP) doses on fetal, neonatal, and adult testosterone production. Pregnant rats were administered DEHP from Gestational Day (GD) 14 day parturition (Postnatal 0). Exposure between 234 1250 mg/kg/day resulted in increases absolute volumes Leydig cells per testis. Despite this, serum levels reduced significantly compared those controls at all doses. Organ cultures testes GD20 exposed utero showed...
Significance Cholesterol-derived steroid hormones are critical mediators in development, reproduction, behavior, and stress response. Steroid biosynthesis occurs hormone-dependent steroidogenic cells, which defined by their ability to cleave cholesterol pregnenolone mitochondria, the adrenal cortex, gonads. The rate-limiting step is transport of from intracellular stores into mitochondria. Translocator protein (TSPO) a high-affinity drug- cholesterol-binding important for import Two distinct...
Abstract In the present study, we examined a panel of human breast cancer cell lines with regard to their expression CD44 and ability bind degrade hyaluronan. The expressed varying amounts different molecular weight forms (85–200 kDa) and, in general, those that greatest were most invasive as judged by vitro assays. addition, hyaluronan was restricted expressing high levels CD44, both these functions blocked an antibody (Hermes‐1). Moreover, rate [ 3 H]hyaluronan degradation highly...
In this study, we hypothesized that many of the reported effects phthalate esters and other peroxisome proliferators (PPs) in testis are mediated by members PP- activated receptor (PPAR) family transcription factors through alterations proteins involved steroidogenesis. Exposure Leydig cells to PPs prevented cholesterol transport into mitochondria after hormonal stimulation inhibited steroid synthesis, without altering total cell protein synthesis or mitochondrial DNA integrity. also reduced...
In utero exposure to di-(2-ethylhexyl) phthalate (DEHP) has been shown result in decreased androgen formation by fetal and adult rat testes. the fetus, is accompanied reduced expression of steroidogenic enzymes. The mechanism which results adult, however, unknown. We hypothesized that deregulation nuclear steroid receptors might explain effects DEHP on testosterone production. To test this hypothesis, pregnant Sprague Dawley dams were gavaged with 100-950 mg per kilogram day from gestational...
Fatty acid metabolism and steroid biosynthesis are 2 major pathways shared by peroxisomes mitochondria. Both organelles in close apposition to the endoplasmic reticulum, with which they communicate via interorganelle membrane contact sites promote cellular signaling exchange of ions lipids. To date, no convincing evidence direct between mitochondria was reported mammalian cells. Hormone-induced, tightly controlled hormone requires interactions. Using immunofluorescent staining live-cell...
We previously reported that in utero exposure of the male fetus to plasticizer di-(2-ethylhexyl) phthalate (DEHP) resulted decreased circulating levels testosterone adult without affecting Leydig cell numbers, luteinizing hormone levels, or steroidogenic enzyme expression. Fetal DEHP reduced mineralocorticoid receptor (MR; NR3C2) expression cells. In present studies, treatment pregnant Sprague-Dawley dams from Gestational Day 14 until birth with 20, 50, 100, 300, 750 mg kg(-1) day(-1)...
The cellular mechanisms responsible for age-related decline in the ability of Leydig cells to produce testosterone are not yet fully understood. production could result from a reduction cell enzymatic activities mediating synthesis, amount substrate available these enzymes, or both. In present study, we examined effect age on critical early step steroidogenic pathway, transport cholesterol into mitochondria. were isolated testes young and old Brown Norway rats incubated with human chorionic...