Rabbit Anti-Human MMP2 polyclonal antibody

In this study, the chemokine substance P (SP) was inserted into multilayered systems on titanium (Ti)-based substrates for endogenous mesenchymal stem cell (MSC) recruitment to facilitate bone healing. The multilayer was constructed with cationic chitosan (Chi), SP and anionic gelatin (Gel) via a spin-coater-assisted layer-by-layer (LBL) approach. The characterization results demonstrated that the multilayer system was successfully constructed and was capable of continuously releasing SP for almost 2 weeks. We further confirmed that MSCs grown on SP-modified Ti-based substrates showed improved migration capabilities as well as enhanced secretion of matrix metalloproteinases (MMP2, MMP9), rather than enhanced MSC proliferation and differentiation in vitro. In the CD29(+)/CD90(+) double immunofluorescence assay, the Ti/LBL-SP group showed the highest number of MSCs migrating to the peri-implant area after implantation. Consistently, the Ti/LBL-SP implants also significantly enhanced new bone formation according to the results of micro-CT scanning analysis, H&E staining, Masson's trichrome staining and immunohistochemical staining. The obtained results reveal that SP-modified Ti-based substrates were beneficial for bone formation via recruiting endogenous MSCs.

The Drosophila heart provides a simple model to examine the remodelling of muscle insertions with growth, extracellular matrix (ECM) turnover, and fibrosis. Between hatching and pupation, the Drosophila heart increases in length five-fold. If major cardiac ECM components are secreted remotely, how is ECM "self assembly" regulated? We explored whether ECM proteases were required to maintain the morphology of a growing heart while the cardiac ECM expanded. An increase in expression of Drosophila's single tissue inhibitor of metalloproteinase (TIMP), or reduced function of metalloproteinase MMP2, resulted in fibrosis and ectopic deposition of two ECM Collagens; type-IV and fibrillar Pericardin. Significant accumulations of Collagen-IV (Viking) developed on the pericardium and in the lumen of the heart. Congenital defects in Pericardin deposition misdirected further assembly in the larva. Reduced metalloproteinase activity during growth also increased Pericardin fibre accumulation in ECM suspending the heart. Although MMP2 expression was required to remodel and position cardiomyocyte cell junctions, reduced MMP function did not impair expansion of the heart. A previous study revealed that MMP2 negatively regulates the size of the luminal cell surface in the embryonic heart. Cardiomyocytes align at the midline, but do not adhere to enclose a heart lumen in MMP2 mutant embryos. Nevertheless, these embryos hatch and produce viable larvae with bifurcated hearts, indicating a secondary pathway to lumen formation between ipsilateral cardiomyocytes. MMP-mediated remodelling of the ECM is required for organogenesis, and to prevent assembly of excess or ectopic ECM protein during growth. MMPs are not essential for normal growth of the Drosophila heart.