Kai Zhang1, Fuwei Liu1, Dan Jin1, Ting Guo2, Rui Hou1, Junrui Zhang1, Bin Lu1, Yan Hou1, Xin Zhao3, Yunpeng Li4. 1. State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, China. 2. Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiang Su, China. 3. Out-patient department, The Fourth Military Medical University, China. 4. State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, China. Electronic address: lypeng@fmmu.edu.cn.
Abstract
OBJECTIVE: To investigate how a high glucose environment influences the osteogenic ability of periodontal ligament stem cells (PDLSCs) and the function of autophagy in this process, we explored whether the osteogenic ability of PDLSCs could be protected by autophagy. DESIGN: PDLSC proliferation and osteogenesis were evaluated by CCK-8 and western blotting under gradient glucose conditions. The Autophagy RT2 Profiler PCR Array was used to screen autophagy-related mRNA expression during PDLSC osteoblastic differentiation on 5.5 mM + osteogenic induction (OI) medium or 25 mM + OI medium on day 3. Autophagy was regulated by an inducer (rapamycin) and inhibitor (bafilomycin) to investigate its protective effects on PDLSCs. A periodontal trauma model was established in diabetic rats to verify the effects of enhanced autophagy activity on PDLSCs. RESULTS: A high glucose concentration (25 mM) impeded PDLSC proliferation on day 1, and compared with the control condition, high glucose also decreased the osteogenic ability of PDLSCs. The Autophagy RT2 Profiler PCR Array showed obvious fluctuations in many autophagy-related genes, such as ULK1 (9.27), MTOR (3.15), MAP1LC3B (4.22), GABARAPL1 (7.09), ATG10 (6.5), AMPK14 (4.47), WIPI1 (3.29), and IGF1 (24.65). Compared with the control condition, an autophagy inducer or inhibitor markedly impaired or enhanced osteogenic differentiation in cells. The diabetic rat periodontal trauma model demonstrated that periodontium tissue partly recovered in the autophagy-enhanced cell injection diabetic rat group. CONCLUSIONS: High glucose inhibited the activity of PDLSCs, and regulating autophagy protected cell function. Upregulating autophagy partially reversed the adverse effect of high glucose conditions on PDLSCs.
OBJECTIVE: To investigate how a high glucose environment influences the osteogenic ability of periodontal ligament stem cells (PDLSCs) and the function of autophagy in this process, we explored whether the osteogenic ability of PDLSCs could be protected by autophagy. DESIGN: PDLSC proliferation and osteogenesis were evaluated by CCK-8 and western blotting under gradient glucose conditions. The Autophagy RT2 Profiler PCR Array was used to screen autophagy-related mRNA expression during PDLSC osteoblastic differentiation on 5.5 mM + osteogenic induction (OI) medium or 25 mM + OI medium on day 3. Autophagy was regulated by an inducer (rapamycin) and inhibitor (bafilomycin) to investigate its protective effects on PDLSCs. A periodontal trauma model was established in diabeticrats to verify the effects of enhanced autophagy activity on PDLSCs. RESULTS: A high glucose concentration (25 mM) impeded PDLSC proliferation on day 1, and compared with the control condition, high glucose also decreased the osteogenic ability of PDLSCs. The Autophagy RT2 Profiler PCR Array showed obvious fluctuations in many autophagy-related genes, such as ULK1 (9.27), MTOR (3.15), MAP1LC3B (4.22), GABARAPL1 (7.09), ATG10 (6.5), AMPK14 (4.47), WIPI1 (3.29), and IGF1 (24.65). Compared with the control condition, an autophagy inducer or inhibitor markedly impaired or enhanced osteogenic differentiation in cells. The diabeticrat periodontal trauma model demonstrated that periodontium tissue partly recovered in the autophagy-enhanced cell injection diabeticrat group. CONCLUSIONS: High glucose inhibited the activity of PDLSCs, and regulating autophagy protected cell function. Upregulating autophagy partially reversed the adverse effect of high glucose conditions on PDLSCs.