cyclin-d1 and plerixafor

Subchondral bone sclerosis is a major feature of osteoarthritis (OA), and bone marrow mesenchymal stem cells (BMSCs) are presumed to play an important role in subchondral bone sclerosis. Accumulating evidence has shown that stromal cell-derived factor-1α (SDF-1α) plays a key role in bone metabolism-related diseases, but its role in OA pathogenesis remains largely unknown. The purpose of this study was to explore the role of SDF-1α expressed on BMSCs in subchondral bone sclerosis in an OA model.. In the present study, C57BL/6J mice were divided into the following three groups: the sham control, destabilization of the medial meniscus (DMM), and AMD3100-treated DMM (DMM + AMD3100) groups. The mice were sacrificed after 2 or 8 weeks, and samples were collected for histological and immunohistochemical analyses. OA severity was assessed by performing hematoxylin and eosin (HE) and safranin O-fast green staining. SDF-1α expression in the OA model was measured using an enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (q-PCR), and immunohistochemistry. Micro-CT was used to observe changes in subchondral bone in the OA model. CD44, CD90, RUNX2, and OCN expression in subchondral bone were measured using q-PCR and immunohistochemistry. In vitro, BMSCs were transfected with a recombinant lentivirus expressing SDF-1α, an empty vector (EV), or siRNA-SDF-1α. Western blot analysis, q-PCR, and immunofluorescence staining were used to confirm the successful transfection of BMSCs. The effect of SDF-1α on BMSC proliferation was evaluated by performing a CCK-8 assay and cell cycle analysis. The effect of SDF-1α on the osteogenic differentiation of BMSCs was assessed by performing alkaline phosphatase (ALP) and alizarin red S (ARS) staining. Cyclin D1, RUNX2 and OCN expression were measured using Western blot analysis, q-PCR, and immunofluorescence staining.. SDF-1α expression in the DMM-induced OA model increased. In the DMM + AMD3100 group, subchondral bone sclerosis was alleviated, OA was effectively relieved, and CD44, CD90, RUNX2, and OCN expression in subchondral bone was decreased. In vitro, high levels of SDF-1α promoted BMSC proliferation and increased osteogenic differentiation. Cyclin D1, RUNX2, and OCN expression increased.. The results of this study reveal a new molecular mechanism underlying the pathogenesis of OA. The targeted regulation of SDF-1α may be clinically effective in suppressing OA progression.

Topics: Animals; Bone Marrow Cells; Cell Differentiation; Cell Proliferation; Cells, Cultured; Chemokine CXCL12; Core Binding Factor Alpha 1 Subunit; Cyclin D1; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Osteoarthritis; Osteogenesis; Sclerosis

The role of the SDF-1alpha-CXCR4 axis in response to myocardial infarction is unknown. We addressed it using the CXCR4 antagonist, AMD3100, to block SDF-1alpha interaction with CXCR4 after chronic coronary artery ligation. Chronic AMD3100 treatment decreased ejection fraction and fractional shortening in mice 20days after myocardial infarction compared with vehicle-treated mice (echocardiography). Morphometric analysis showed hearts of AMD3100-treated infarcted mice to have expanded scar, to be hypertrophic (confirmed by myocyte cross-section area) and dilated, with increased LV end systolic and end diastolic dimensions, and to have decreased scar collagen content; p-AKT levels were attenuated and this was accompanied by increased apoptosis. Despite increased injury, c-kit(pos) cardiac progenitor cells (CPCs) were increased in the risk region of AMD3100-treated infarcted mice; CPCs were CD34(neg)/CD45(neg) with the majority undergoing symmetric cell division. c-kit(pos)/MHC(pos) CPCs also increased in the risk region of the AMD3100-treated infarcted group. In this group, GSK-3beta signaling was attenuated compared to vehicle-treated, possibly accounting for increased proliferation and increased cardiac committed MHC(pos) CPCs. Increased proliferation following AMD3100 treatment was supported by increased levels of cyclin D1, a consequence of increased prolyl isomerase, Pin1, and decreased cyclin D1 phosphorylation. In summary, pharmacologic antagonism of CXCR4 demonstrates that SDF-1alpha-CXCR4 signaling plays an important role during and after myocardial infarction and that it exerts pleiotropic salubrious effects, protecting the myocardium from apoptotic cell death, facilitating scar formation, restricting CPC proliferation, and directing CPCs toward a cardiac fate.

Topics: Animals; Benzylamines; Blotting, Western; Chemokine CXCL12; Cyclams; Cyclin D1; Echocardiography; Heterocyclic Compounds; Male; Mice; Mice, Inbred C57BL; Myocardial Infarction; NIMA-Interacting Peptidylprolyl Isomerase; Peptidylprolyl Isomerase; Phosphorylation; Protein Binding; Receptors, CXCR4