Suppression of osteoblast-related genes during osteogenic differentiation of adipose tissue derived stromal cells

Characterisation and Expression of Osteogenic and Periodontal Markers of Bone Marrow Mesenchymal Stem Cells (BM-MSCs) from Diabetic Knee Joints

Type 2 diabetes mellitus (T2DM) represents a significant health problem globally and is linked to a number of complications such as cardiovascular disease, bone fragility and periodontitis. Autologous bone marrow mesenchymal stem cells (BM-MSCs) are a promising therapeutic approach for bone and periodontal regeneration; however, the effect of T2DM on the expression of osteogenic and periodontal markers in BM-MSCs is not fully established. Furthermore, the effect of the presence of comorbidities such as diabetes and osteoarthritis on BM-MSCs is also yet to be investigated. In the present study, BM-MSCs were isolated from osteoarthritic knee joints of diabetic and nondiabetic donors. Both cell groups were compared for their clonogenicity, proliferation rates, MSC enumeration and expression of surface markers. Formation of calcified deposits and expression of osteogenic and periodontal markers were assessed after 1, 2 and 3 weeks of basal and osteogenic culture. Diabetic and nondiabetic BM-MSCs showed similar clonogenic and growth potentials along with comparable numbers of MSCs. However, diabetic BM-MSCs displayed lower expression of periostin (POSTN) and cementum protein 1 (CEMP-1) at Wk3 osteogenic and Wk1 basal cultures, respectively. BM-MSCs from T2DM patients might be suitable candidates for stem cell-based therapeutics. However, further investigations into these cells' behaviours in vitro and in vivo under inflammatory environments and hyperglycaemic conditions are still required.

Programmable cells of monocytic origin as a source of osteochondroprogenitors: Effect of growth factors on osteogenic differentiation

We have demonstrated previously that peripheral blood monocytes can be converted in vitro to a multipotent stem cell-like cell termed programmable cell of monocytic origin (PCMO) and subsequently into cells with chondrocyte-like phenotype. Here, we investigated whether PCMO could also be differentiated into osteoblast-like cells using growth factors with known osteoinductive potency. Following stimulation with BMP-2, BMP-7, IGF-1 or TGF-β1 for 7 and 14 days, PCMOs were analyzed for mRNA expression of collagen types I and V, alkaline phosphatase, osteocalcin, runt-related transcription factor-2 (Runx2) and Osterix (Osx) by quantitative RT-PCR (qPCR) and the levels of collagen I in culture supernatants by ELISA. The expression of osteoblastic markers was evident, albeit at a different extent in cultures of PCMOs after treatment with the above-mentioned growth factors. Culture supernatants from PCMOs stimulated for 6-10 days with BMP-2, BMP-7, IGF-1 or TGF-β1 contained high levels of collagen type I, together with earlier data indicating synthesis and proper secretion. The findings suggest that PCMOs can transform into cells that are phenotypically similar to osteoblasts and identify these cells as osteochondroprogenitors. The possibility of differentiating PCMOs from peripheral blood in sizable quantities could be a novel way to obtain autologous bone-like substitutes without donor-site morbidity.