Cometti Barbara P S, Dubey Raghvendra K, Imthurn Bruno, Rosselli Marinella (2018), Natural and environmental oestrogens induce TGFB1 synthesis in oviduct cells, in Reproduction
, 155(3), 233-244.
Popa Mirel-Adrian, Mihai Maria-Cristina, Constantin Alina, Şuică Viorel, Ţucureanu Cătălin, Costache Raluca, Antohe Felicia, Dubey Raghvendra K, Simionescu Maya (2018), Dihydrotestosterone induces pro-angiogenic factors and assists homing of MSC into the cardiac tissue, in Journal of Molecular Endocrinology
, 60(1), 1-15.
Dubey Raghvendra K. (2017), 2-MethoxyestradiolA 17β-Estradiol Metabolite With Gender-Independent Therapeutic Potential, in Hypertension
, 69(6), 1014-1016.
Samartzis Eleftherios P., Imesch Patrick, Twiehaus Anja, Dubey Raghvendra K., Leeners Brigitte (2016), The estrogen metabolites 2-methoxyestradiol and 2-hydroxyestradiol inhibit endometriotic cell proliferation in estrogen-receptor-independent manner, in Gynecological Endocrinology
, 32(7), 529-533.
Schaufelberger Sara A., Rosselli Marinella, Barchiesi Federica, Gillespie Delbert G., Jackson Edwin K., Dubey Raghvendra K. (2016), 2-Methoxyestradiol, an endogenous 17β-estradiol metabolite, inhibits microglial proliferation and activation via an estrogen receptor-independent mechanism, in American Journal of Physiology-Endocrinology and Metabolism
, 310(5), E313-E322.
UnterleutnerElisabeth (2016), Role of G-protein Coupled Estrogen Receptor in Mediating the Vasoprotective Actions of Estradiol
, ETH Zurich Library, Zurich.
Rigassi Lisa, Barchiesi Bozzolo Federica, Lucchinetti Eliana, Zaugg Michael, Fingerle Jürgen, Rosselli Marinella, Imthurn Bruno, Jackson Edwin K., Dubey Raghvendra K. (2015), 2-Methoxyestradiol blocks the RhoA/ROCK1 pathway in human aortic smooth muscle cells, in American Journal of Physiology-Endocrinology and Metabolism
, 309(12), E995-E1007.
Yulia Plutino (2015), Defining the Role of Androgens in Vascular Remodeling Associated with Cardiovascular Disease
, ETH E-collection ETH Institutional Repository, Swiss Federal Institute of Tschnology Zurich.
Mihai Cristina, Popa Mirel-Adrien, Viorel Julian, Antohe Felicia, Jackson Edwin, Simionescu Maya, Dubey Raghvendra, 17Beta-Estradiol Stimulated Integration of Human Mesenchymal Stem Cells in Heart Tissue, in Journal of Molecular and Cellular Cardiology
, 133, 115-124.
Dubey Raghvendra, Fingerle J, Gillespie DG, Mi Z, Rosselli M, Imthurn B, Jackson EK, , Adenosine Attenuates Human Coronary Artery Smooth Muscle Cell Proliferation by Inhibiting Multiple Signaling Pathways That Converge on Cyclin D, in Hypertension
Summary Hormone therapy (HT) with estrogen alleviates multiple postmenopausal disorders. Epidemiological/observational studies provide strong evidence the estrogens protect women against cardiovascular disease, however, results from two randomized clinical trials with conjugated equine estrogens (HERS and WHI study) showed no primary or secondary cardiovascular protective effects. However, another trial using estradiol (EPAT) demonstrated cardiovascular protective effects, additionally, protective effects were also observed in a sub-population of PMW who initiated HT within 10 years of menopause. The differences in the outcome of these studies remain controversial. Because the mechanisms by which estrogens induce their cardiovascular protective and/or deleterious effects are unclear and several different types of estrogens are used clinically it is hard to explain the reasons for these differential effects and underscores the need to explore basic mechanisms of cardiovascular protection by estrogens. Ongoing studies from our laboratory demonstrate that 2-methoxyestradiol (2-ME), a major metabolite of 17ß-estradiol with no binding affinity for estrogen receptors (ERs), is more potent than 17ß-estradiol in inhibiting vascular smooth muscle cell (SMC) and cardiac fibroblast (CF) growth. These observations, together with the findings that estradiol inhibits injury-induced neointima formation in mice lacking the functional ER-a, ER-ß, or both ER-a and ER-ß, led us to hypothesize that in addition to ERs, estradiol metabolites, are also responsible for the cardiovascular protection afforded by estrogen therapy and that variable metabolism of estrogen(s) explains the inconsistent clinical response to HRT. In this context using molecular (siRNA; knock out mice) and pharmacological approaches we previously demonstrated that ER-independent anti-proliferative effects of estradiol is mediated via its sequential conversion to methoxyestradiols. Because, 2-ME is anticarcinogenic it may serve as a safer alternative for HT. Hence using cellular (vascular cells and bone marrow derived progenitor cells), molecular (gene silencing, microarrays) and biochemical approaches, the objective of this proposal is to investigate the mechanisms by which estradiol, 2-ME and estradiol-derived 2-ME influences key mechanisms associated with the pathophysiology of vascular remodeling process in coronary artery disease (CAD) and atherosclerosis. We have previously shown that sequential metabolism of estradiol to methoxyestradiol by CYP450 and COMT is responsible for its antimitogenic actions on vascular SMCs. However, in depth mechanisms via which 2-ME inhibits vascular remodeling process associated with CAD/atherosclerosis is still lacking. Hence in this proposal, using molecular, biochemical and pharmacological techniques in cultured human bone marrow derived progenitor-SMCs (contributes to neointima formation by 66%), and progenitor-endothelial cells (PECs), and SMCs we will evaluate the impact of estradiol, 2-ME and estradiol-derived 2-ME on key pathways associated with cardiovascular remodeling process in CAD/atherosclerosis. In this context the influence of estradiol, 2-ME or estradiol-derived 2-ME intracellular mechanisms regulating progenitor-SMC and SMC-proliferation, apoptosis and PECs-induced neo-vascularization will be assessed. As an extension of our previous findings that estradiol, 2-ME and estradiol-derived 2-ME inhibits SMC growth by interfering with pathways regulating cell cycle, using gene silencing/pharmacological inhibitors, we will study the role of sequential metabolism of estradiol to 2-ME in inhibiting signal transduction pathways in progenitor-SMCs by assaying the effects on the mitogen-activated protein kinase (ERK1/2), the protein kinase C (PKC) pathway, Akt-phosphorylation, cyclin dependent kinases (cdc2/cdk1, cdk2); cyclins A and E, and tubulin polymerization, and cdk-inhibitors (p21/p27). Moreover, we will study whether estradiol and 2-ME induce apoptosis in Progenitor-SMCs by utilizing TUNNEL assay, DNA fragmentation, and modulatory effects on various extrinsic and intrinsic apoptotic pathways (mitochondrial release of cytochrome c; disappearance of 21KDa Bid protein; cleavage of procaspase 3, 8, and 9; oxidative stress-H202 release; stress activated c-jun NH2 terminal [JNK-P]; Fas ligand and Fas associated death domain protein [FADD]). We recently showed that 2-ME lowers cholesterol levels, and downregulates genes for cholesterol synthesis pathway and Rho-pathway in SMCs. Since estradiol and 2-ME inhibit cholesterol-induced atherosclerosis, and activation of Rho-pathway induces CAD; we will investigate the mechanism(s) via which estradiol and 2-ME influence cholesterol synthesis and the Rho-kinase pathway in SMCs and progenitor-SMCs. Growth of ECs and PECs in response to estradiol helps in vascular recovery. We recently showed that estradiol stimulates capillary formation by PECs via a membrane ER linked to ER-?. Since GPR30 is a new membrane bound ER, we will study its role in mediatig estradiol-induced capillary formation. Additionally, the impact of 2-ME on the growth of PECs which contribute to capillary formation in plaques will be assessed. Finally, using human micro-array gene chips we will screen and document the early and late genes that are influenced by estradiol and 2-ME and subsequently analyze their role in mediating the antivasoocclusive actions.Potential Implications: If our hypothesis is correct and the estrogen metabolites are cardioprotective, then non-estrogenic and non-carcinogenic estrogen metabolites, such as 2-ME, could be employed for prevention of cardiovascular disease in both men and women without increasing the risk of cancer. Also, our hypothesis would explain the variable response to estrogens in PMW and would predict that therapy with estrogen metabolites would afford cardioprotection regardless of inter-individual differences in estrogen metabolism.