L Xing1, Y Geng2, W Li3, L Lin3, P Xu3. 1. Department of Oral Implantology, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou Key Laboratory of Basic and Applied Research in Oral Regenerative Medicine, Guangzhou 510182, China. 2. Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. 3. Stomatological Hospital, Southern Medical University, Guangzhou 510280, China.
Abstract
OBJECTIVE: To investigate the association of the expressions of RUNX2/LAPTM5 with osteogenesis and lysosomes in osteoblastic cells during mineralization induction. METHODS: MC3T3- E1 cells cultured in osteogenic induction medium was examined for mineralization and osteogenic differentiation using Alizarin red staining and alkaline phosphatase (ALP) staining, respectively. RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of Runx2 and LAPTM5 in the cells during osteogenic induction for 5 days. The effects of overexpression and interference of RUNX2/ LAPTM5 on the expressions of ALP and osteocalcin (OCN) in the cells were examined with Western blotting. RESULTS: MC3T3- E1 cells cultured in osteogenic induction medium showed an increased number of mineralized nodules over time, and the size of the mineralized nodules increased as the culture time extended; the number of purple-blue granules stained by ALP also increased gradually with time. RT-qPCR and Western blotting showed that the expressions of RUNX2 and LAPTM5 in the cells increased progressively during osteogenic mineralization (P < 0.001). Overexpression and interference of RUNX2 obviously affected LAPTM5 expression in the cells (P < 0.05); modulation of LAPTM5 expression did not significantly affect RUNX2 expression but caused significant changes in ALP and OCN expressions (P < 0.01). CONCLUSION: RUNX2 /LAPTM5 may participate in the regulation of osteoblast differentiation, and RUNX2 may be involved in the regulation of LAPTM5 expression. RUNX2 /LAPTM5 may play a mediating role in the process of osteogenic mineralization involving lysosomes.
OBJECTIVE: To investigate the association of the expressions of RUNX2/LAPTM5 with osteogenesis and lysosomes in osteoblastic cells during mineralization induction. METHODS: MC3T3- E1 cells cultured in osteogenic induction medium was examined for mineralization and osteogenic differentiation using Alizarin red staining and alkaline phosphatase (ALP) staining, respectively. RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of Runx2 and LAPTM5 in the cells during osteogenic induction for 5 days. The effects of overexpression and interference of RUNX2/ LAPTM5 on the expressions of ALP and osteocalcin (OCN) in the cells were examined with Western blotting. RESULTS: MC3T3- E1 cells cultured in osteogenic induction medium showed an increased number of mineralized nodules over time, and the size of the mineralized nodules increased as the culture time extended; the number of purple-blue granules stained by ALP also increased gradually with time. RT-qPCR and Western blotting showed that the expressions of RUNX2 and LAPTM5 in the cells increased progressively during osteogenic mineralization (P < 0.001). Overexpression and interference of RUNX2 obviously affected LAPTM5 expression in the cells (P < 0.05); modulation of LAPTM5 expression did not significantly affect RUNX2 expression but caused significant changes in ALP and OCN expressions (P < 0.01). CONCLUSION: RUNX2 /LAPTM5 may participate in the regulation of osteoblast differentiation, and RUNX2 may be involved in the regulation of LAPTM5 expression. RUNX2 /LAPTM5 may play a mediating role in the process of osteogenic mineralization involving lysosomes.
Authors: C N Adra; S Zhu; J L Ko; J C Guillemot; A M Cuervo; H Kobayashi; T Horiuchi; J M Lelias; J D Rowley; B Lim Journal: Genomics Date: 1996-07-15 Impact factor: 5.736
Authors: Haibo Zhao; Yuji Ito; Jean Chappel; Norma W Andrews; Steven L Teitelbaum; F Patrick Ross Journal: Dev Cell Date: 2008-06 Impact factor: 12.270