ABSTRACT
Matrix metalloproteinase-2 (MMP-2), also known as gelatinase A, is involved in vascular calcification. Another member of gelatinases is MMP-9 (gelatinase B). However, the role of gelatinases in the pathogenesis of vascular calcification is not well understood. The current study aims to clarify the relationship between gelatinases and vascular calcification and to elucidate the underlying mechanism. Beta-glycerophosphate (ß-GP) was used to induce calcification of vascular smooth muscle cells (VSMCs) with or without 2-[[(4-Phenoxyphenyl)sulfonyl]methyl]-thiirane (SB-3CT), a specific gelatinases inhibitor. Levels of calcification were determined by assessing calcium content and calcification area of VSMCs. Phenotype transition of VSMCs was observed by assessing expressions of alkaline phosphatase (ALP), smooth muscle α-actin (SM-α-actin) and desmin. Gelatin zymography was applied to determine the activities of gelatinases, and western blot was applied to determine expressions of gelatinases, bone morphogenetic protein-2 (BMP-2), Runt-related transcription factor 2 (RUNX2) and msh homeobox homolog 2 (Msx-2). Gelatinases inhibition by SB-3CT alleviated calcification and phenotype transition of VSMCs induced by ß-GP. Increased gelatinases expression and active MMP-2 were observed in calcifying VSMCs. Gelatinases inhibition reduced expression of RUNX2, Msx-2 and BMP-2. BMP-2 treatment increased expressions of RUNX2 and Msx-2, while noggin, an antagonist of BMP-2, decreased expressions of RUNX2 and Msx-2. Gelatinases promote vascular calcification by upregulating BMP-2 which induces expression of RUNX2 and Msx-2, two proteins associated with phenotype transition of VSMCs in vascular calcification. Interventions targeting gelatinases inhibition might be a proper candidate for ameliorating vascular calcification.
Subject(s)
Bone Morphogenetic Protein 2/metabolism , Gelatinases/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Vascular Calcification/metabolism , Vascular Calcification/pathology , Animals , Cells, Cultured , Male , Muscle, Smooth, Vascular/pathology , Rats , Rats, Wistar , Up-RegulationABSTRACT
Dynamic tracking of microvascular and microlymphatic vasomotion presents a critical image processing technique in the evaluation of function and dysfunction of the microvasculature. Many methods for determination of diameter changes have been reported. Previous methods which were specifically developed for vasomotion tracking of intravital, fluorescence-free, rapidly constricting microvascular and microlymphatic vessels have various limitations due to complex image background, vessel wall distortion, image drift, noise and other artifacts. In order to overcome these major obstacles and remove undesirable limitations, this study proposed a tracking strategy based on feature matching of moving object-VasTrack. First, we calculate the image drift vector by feature template matching of a landmark in the background. Second, dynamically regulate the position of a sample line in accordance with the drift vector for sustaining the consistency of measurement location. Third, dynamically recognize and track edge position changes by applying feature template matching using edge context. This method does not require special preprocessing of video image registration and rotation. VasTrack compensates efficiently for image drift and vessel wall distortion, can simultaneously track and determine vessel diameters at any orientation and in multiple locations. Testing proved that VasTrack is robust and accurate, and will satisfy the needs of basic microcirculatory research and clinical inspection.
