Assessing the effects of cyclosporine A on the osteoblastogenesis, osteoclastogenesis, and angiogenesis mediated by the human periodontal ligament stem cells

BACKGROUND: This study was performed to investigate the effects of cyclosporine A (CsA) on the osteogenic differentiation, osteoclastogenic-supporting ability, and angiogenic potential of human periodontal ligament stem cells (hPDLSCs). METHODS: hPDLSCs were isolated from the extracted teeth of orthodontic patients. Cell proliferation was assessed using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, and osteogenic differentiation was evaluated by alkaline phosphatase (ALP) and alizarin red (ARS) staining. Real-time polymerase chain reaction (PCR) was used to quantify transcripts. Tartrate-resistant acid phosphatase staining of bone marrow-derived macrophages (BMMs) and tube formation assays on human umbilical vein endothelial cells (HUVECs) were performed after treating cells with the conditioned media from CsA-exposed or non-exposed hPDLSCs. Signaling pathways mediating the angiogenic activity were investigated using western blotting. RESULTS: CsA suppressed the proliferation of hPDLSCs but enhanced osteogenic differentiation as determined by ALP and ARS staining and PCR of osteogenic transcripts. The expressions of osteoclastogenic transcripts in hPDLSCs and the differentiation of BMMs treated with conditioned medium from CsA-exposed hPDLSCs were unaffected by CsA. However, the expressions of angiogenic transcripts and the transcripts known to support angiogenesis-phosphorylation of extracellular signal p-regulated kinase (ERK) and p38, and c-fos-were inhibited. Conditioned medium from CsA-exposed hPDLSCs suppressed the tube forming abilities of HUVECs. CONCLUSIONS: CsA enhanced the osteogenic differentiation and reduced angiogenesis by blocking the ERK and p38/c-fos pathway in hPDLSCs. It is necessary to confirm whether this phenomenon is also observed in vivo in subsequent animal experiments.