Alternative Roles of STAT3 and MAPK Signaling Pathways in the MMPs Activation and Progression of Lung Injury Induced by Cigarette Smoke Exposure in ACE2 Knockout Mice.

Inflammation-mediated abnormalities in the renin-angiotensin system (RAS) and expression of matrix metalloproteinases (MMPs) are implicated in the pathogenesis of lung injury. Angiotensin converting enzyme II (ACE2), an angiotensin converting enzyme (ACE) homologue that displays antagonist effects on ACE/angiotensin II (Ang II) axis, could also play a protective role against lung diseases. However, the relationship between ACE2 and MMPs activation in lung injury is still largely unclear.

Matrix metalloproteinase 2 level in human follicular fluid is a reliable marker of human oocyte maturation in in vitro fertilization and intracytoplasmic sperm injection cycles.

Background: To determine whether matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMP-1 and TIMP-2) in human follicular fluid, have any relationships with oocyte maturation in vivo and subsequent fertilization during in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles.

Methods: The follicular fluids were obtained from 150 female patients undergoing IVF/ICSI cycles and a total of 1504 oocytes were retrieved for analysis. MMP-2 and MMP-9 activities were measured using zymography assay.