Centre de Recherche en Reproduction Animale, Université de Montréal, St-Hyacinthe, Quebec, Canada.
Published: December 2011
AI Article Synopsis
Article Abstract
Angiotensin II (AGT-2) induces follicular prostaglandin release in a number of species and ovulation in rabbits. Conversely, AGT-2 antagonists block ovulation in cattle. To determine the mechanism of action of AGT-2, we used a bovine granulosa cell model in which luteinizing hormone (LH) increased the expression of genes essential for ovulation in a time- and dose-dependent manner. The addition of AGT-2 to LH-stimulated cells significantly increased abundance of prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA and protein, whereas AGT-2 alone had no effect. Upstream of PTGS2, AGT-2 increased abundance of mRNA encoding the epidermal growth factor-like ligands amphiregulin (AREG) and epiregulin (EREG) at 6 h posttreatment and abundance of a disintegrin and metalloprotease 17 (ADAM17), a sheddase, within 3 h of treatment. Inhibiting sheddase activity abolished the stimulatory effect of AGT-2 on AREG, EREG, and PTGS2 mRNA. The addition of selective AGT-2 antagonists to cells stimulated with LH plus AGT-2 demonstrated that AGT-2 did not act through the type 1 receptor and did not increase mitogen-activated protein kinase 3/1 phosphorylation. Combined with previous data from studies in vitro, we conclude that AGT-2 is an essential cofactor for LH in the early increase of ADAM expression/activity that induces the cascade of events leading to ovulation.
Departamento de Química Física, Unidad de Excelencia en Química Aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Universidad de Granada, Spain. Electronic address:
To improve protein pharmaceuticals, we need to balance protein stability and binding affinity with in vivo efficiency. We have recently developed a nanobody (NB-AGT-2) against the alanine:glyoxylate aminotransferase with high stability (T ∼ 86 °C) that may be useful to treat a misfolding disease called primary hyperoxaluria type 1. In this work, we characterize the relationships between protein stability and binding affinity in NB-AGT-2 by generating single and double cavity-creating mutants in its hydrophobic core.
Background: he internal mammary artery (IMA) is routinely used as an arterial graft for coronary artery bypass grafting with an excellent long‑term patency rate, but its protective mechanism is unclear.
Aims: We evaluated the differences between the expression of several gene in perivascular adipose tissue from the IMA (PVAT‑IMA) as compared with other fat depots in patients with severe coronary artery disease.
Methods: A total of 53 patients (13 women) with severe coronary artery disease and preserved left ventricular ejection fraction were scheduled for coronary artery bypass grafting.
DNA alkylguanine DNA alkyltransferases (AGTs) are evolutionary conserved proteins that repair alkylation damage in DNA, counteracting the effects of agents inducing such lesions. Over the last years AGTs have raised considerable interest for both the peculiarity of their molecular mechanism and their relevance in cancer biology. AGT knock out mice show increased tumour incidence in response to alkylating agents, and over-expression of the human AGT protein in cancer cells is frequently associated with resistance to alkylating chemotherapy.
Thromboses and stenoses of permanent vascular access appear to be a serious hazard for patients with end-stage kidney disease on programmed haemodialysis. Relapses of these pathological conditions are the cause of repeated hospitalization, secondary surgical interventions and may eventually lead to impossibility of carrying out procedures of haemodialysis. Often, vascular access dysfunction occurs for no apparent reason, thus underlying the importance of studies aimed at revealing additional factors of intravascular thrombogenesis and neointimal formation in a vascular access, including the works dedicated to studying genetic predictors of the development of the above-mentioned complications.
From the Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom and
The renin-angiotensin cascade is a hormone system that regulates blood pressure and fluid balance. Renin-mediated cleavage of the angiotensin I peptide from the N terminus of angiotensinogen (AGT) is the rate-limiting step of this cascade; however, the detailed molecular mechanism underlying this step is unclear. Here, we solved the crystal structures of glycosylated human AGT (2.
