Exendin-4 relieves the inhibitory effects of high glucose on the proliferation and osteoblastic differentiation of periodontal ligament stem cells.

With the impaired regenerative potential in patients with diabetes mellitus (DM), Periodontal ligament stem cells (PDLSCs) are regarded as an attractive source of stem cells for periodontal cytotherapy. Recent studies have shown that Exendin-4 (Ex-4) exerts cell-protective effects and bone remodeling ability on many types of cells. The aim of this study was to investigate whether Ex-4 alleviates the inhibition of high glucose on the proliferation and osteogenic differentiation of PDLSCs. PDLSCs were incubated in medium supplemented with 5.5 mM d-glucose (NG), 30 mM d-glucose (HG), NG plus Ex-4, and HG plus different concentration (1, 10, 20, 100 nM) of Ex-4 respectively. Cell proliferation was detected by CCK-8 assay and cell cycle analysis. Osteogenesis was assessed by Alizarin Red S staining and evaluation of the mRNA expression of Runx2, ALP and Osx at day 7, 14 and 21. Intracellular level of reactive oxygen species (ROS) was detected using 5-(and-6)-chloromethyl-2',7'-dichlorodihydro-fluorescein diacetate (CMH2DCF-DA). The proliferation ability, mineralized nodules forming capacity and the mRNA expression of Runx2, ALP and Osx of PDLSCs in HG group were decreased, the ROS level was increased compared to NG group. With the treatment of Ex-4, the HG-inhibited proliferation ability and osteogenic differentiation ability of PDLSCs were significantly reversed, the HG-increased ROS level could be down-regulated. Moreover, Ex-4 enhanced the osteogenic differentiation of normal PDLSCs. Ex-4 alleviates the inhibitory effect of HG on the proliferation and osteoblastic differentiation of PDLSCs, and has a significant enhance in the osteoblastic differentiation of normal PDLSCs, giving new insights into the possible therapeutic method of diabetic periodontitis.

Guo Z ，Chen R ，Zhang F ，Ding M ，Wang P ... -  《-》

Erythropoietin attenuates high glucose-induced oxidative stress and inhibition of osteogenic differentiation in periodontal ligament stem cell (PDLSCs).

Diabetes mellitus and periodontitis have long been considered to be biologically linked. Erythropoietin (EPO) has multiple biological functions, such as stimulating the proliferation and differentiation of erythroid progenitor cells and reducing glucose-induced oxidative stress via different mechanisms, acting as a direct antioxidant. The purposes of the study to examine the anti-oxidative effect of EPO on reducing high glucose-induced oxidative stress of hPDLSCs and provide a better understanding of the mechanism of these processes. PDLSCs were induced by highglucose (HG, 30 mM) in the presence or absence of EPO. Cell proliferation was measured by MTT assay. The reactiveoxygen species (ROS) level, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were detected to evaluate oxidative stress. qRT-PCR and western blot analysis were used to examine the expression of osteogenic related genes and protein (Runx2 and Osterix). Alizarin Red-S staining was used to detect mineralized nodule formation. The results showed that EPO promote the proliferation of PDLSCs, which was suppressed by high glucose (30 mM). Moreover, EPO attenuated high glucose (30 mM) induced oxidative stress by reducing the levels of ROS and MDA, and increasing the SOD activity. Furthermore,EPO alleviate high glucose(30 mM) induced suppression of osteogenic differentiation ability in PDLSCs, as evidenced by the up-regulated mRNA and protein expression of Runx2 and Osterix and increased ALP activity. In conclusion, EPO attenuates high glucose-induced oxidative stress, inhibitory effect of proliferation and inhibition of osteogenic differentiation in periodontal ligament stem cell (PDLSCs).

Zheng DH ，Han ZQ ，Wang XX ，Ma D ，Zhang J ... -  《-》

Hesperetin alleviates the inhibitory effects of high glucose on the osteoblastic differentiation of periodontal ligament stem cells.

Kim SY ，Lee JY ，Park YD ，Kang KL ，Lee JC ，Heo JS ... -  《PLoS One》

PAR1 Activation, via LMBR1/BMP Axis, Promotes the Osteogenesis of Periodontal Ligament Stem Cells (PDLSCs) and Alleviates the Inhibitory Effect of Sodium Butyrate on PDLSCs Osteogenesis.

Xia L ，Yang Z ，Hu C 《-》

Oxytocin facilitates the proliferation, migration and osteogenic differentiation of human periodontal stem cells in vitro.

To explore the effect of oxytocin (OT) on the proliferation, migration, and osteogenic differentiation of periodontal ligament stem cells (PDLSCs) in vitro. PDLSCs were obtained by limiting dilution method. Immunofluorescence (IF), cell-counting kit-8 (CCK8), cell migration assay, Alizarin Red S staining, cetylpyridinium chloride (CPC) colorimetry, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis were used to examine the effect of OT on oxytocin receptor (OTR) expression, cell proliferation, migration and osteogenic differentiation of PDLSCs. Our study showed that PDLSCs expressed OTR. One hundred nanomolar OT exhibited the maximal effect on migration, while only 50 nM OT significantly promoted proliferation of PDLSCs, as well as mineralized nodule formation and calcium deposition (p < 0.05). Furthermore, 50 nM OT significantly up-regulated expression of osteogenesis-related genes-alkaline phosphatase (ALP), Collagen I (Col I), runt related transcription factor 2 (Runx 2), osteopontin (OPN) and osteocalcin (OCN)-at specific time points compared with osteogenic inductive medium (p < 0.05). In addition, western blot analysis demonstrated that 50 nM OT enhanced protein levels of ALP, Col I, and Runx 2 at day 7 and day 14 (p < 0.01), as well as activating the phosphorylation of extracellular-signal-regulated kinase (ERK) and protein kinase B (AKT) pathway; notably, 50 nM OT inhibited phosphorylation of the phosphatidylinositol 3-kinase (PI3K) pathway (p < 0.05). OT promoted proliferation, migration, and osteogenic differentiation of PDLSCs in vitro. Furthermore, the effect of OT on osteogenic differentiation was mediated through ERK and AKT pathway. Thus, OT may have potential for use in periodontal regeneration.

Ge B ，Liu H ，Liang Q ，Shang L ，Wang T ，Ge S ... -  《-》