scholarly journals Synergistic stimulation of osteoblast differentiation of rat mesenchymal stem cells by leptin and 25(OH)D3 is mediated by inhibition of chaperone-mediated autophagy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qiting He ◽  
Ruixi Qin ◽  
Julie Glowacki ◽  
Shuanhu Zhou ◽  
Jie Shi ◽  
...  

Abstract Background Vitamin D is important for the mineralization of bones by stimulating osteoblast differentiation of bone marrow mesenchymal stem cells (BMMSCs). BMMSCs are a target of vitamin D action, and the metabolism of 25(OH)D3 to biologically active 1α,25(OH)2D3 in BMMSCs promotes osteoblastogenesis in an autocrine/paracrine manner. Our previous study with human BMMSCs showed that megalin is required for the 25(OH)D3-DBP complex to enter cells and for 25(OH)D3 to stimulate osteoblast differentiation in BMMSCs. Furthermore, we reported that leptin up-regulates megalin in those cells. Leptin is a known inhibitor of PI3K/AKT-dependent chaperone-mediated autophagy (CMA). In this study, we tested the hypothesis that leptin acts synergistically with 25(OH)D3 to promote osteoblastogenesis in rat BMMSCs by a mechanism that entails inhibition of PI3K/AKT-dependent CMA. Methods BMMSCs were isolated from rat bone marrow (4-week-old male SD rats); qRT-PCR and western immunoblots or immunofluorescence were used to evaluate the expression of megalin, ALP, COL1A1, RUNX2, OSX, OSP, and CMA in rBMMSCs. The osteoblast differentiation was evaluated by ALP activity, ALP staining, and calcium deposition. The viability of rBMMSCs was assessed with the CCK-8 kit. Biosynthesis of 1α,25(OH)2D3 was measured by a Rat 1α,25(OH)2D3 ELISA Kit. Results The combination of leptin and 25(OH)D3 treatment significantly enhanced osteoblast differentiation as shown by ALP activity, ALP staining, and calcium deposition, the expression of osteogenic genes ALP, COL1A1, RUNX2, OSX, and OSP by qRT-PCR and western immunoblots in rBMMSCs. Leptin enhanced the expression of megalin and synthesis of 1α,25(OH)2D3 in rBMMSCs. Our data showed that leptin inhibited CMA activity of rBMMSCs by activating PI3K/AKT signal pathway; the ability of leptin to enhance 25(OH)D3 promoted osteoblast differentiation of rBMMSCs was weakened by the PI3K/AKT signal pathway inhibitor. Conclusions Our data reveal the mechanism by which leptin and 25(OH)D3 promote osteoblast differentiation in rBMMSCs. Leptin promoted the expression of megalin by inhibiting CMA, increased the utilization of 25(OH)D3 by rBMMSCs, and enhanced the ability of 25(OH)D3 to induce osteoblast differentiation of rBMMSCs. PI3K/AKT is at least partially involved in the regulation of CMA. These data indicate the importance of megalin in BMMSCs for vitamin D’s role in skeletal health.

2021 ◽  
Author(s):  
Qiting He ◽  
Ruixi Qin ◽  
Julie Glowacki ◽  
Shuanhu Zhou ◽  
Jie Shi ◽  
...  

Abstract Background 25(OH)D3 is important for the osteoblast differentiation of bone marrow mesenchymual stem cells (BMMSCs), BMMSCs can directly hydroxylate 25(OH)D3 to 1α,25(OH)2D3 to induce osteoblast differentiation. Our previous research with human BMMSCs showed that the cell membrane receptor megalin is required for the 25(OH)D3-DBP complex to enter cells and thereby to stimulate osteoblast differentiation. Furthermore, leptin was shown to upregulate megalin in those cells. Leptin is a known inhibitor of PI3K/AKT-dependent chaperone-mediated autophagy (CMA). In this study, we tested the hypothesis that leptin acts synergistically with 25(OH)D3 to promote osteoblastogenesis in rat BMMSCs by a mechanism that entails inhibition of PI3K/AKT-dependent CMA. Methods The BMMSCs were isolated from rat bone marrow, qRT-PCR and western immunoblots were used to evaluate the expression of megalin, ALP, COL1A1, RUNX2 and CMA activity. The osteoblast differentiation ability was evaluated by ALP activity, ALP staining, and calcium deposition. Results After rBMMSCs were exposed to a combination of leptin and 25(OH)D3, osteoblast differentiation was significantly enhanced, the expression of osteoblastogenic genes ALP, COL1A1, and RUNX2 by qRT-PCR were up-regulated, and ALP activity, ALP staining, and calcium deposition were also significantly increased. The quantity of 25(OH)D3 entering rBMMSCs was increased through increased megalin receptors, and ELISA confirmed that the synthesis of 1α,25(OH)2D3 was increased. Addition of a PI3K/AKT inhibitor reduced the synergistic effect of osteoblast differentiation of rBMMSCs induced by combination leptin with 25(OH)D3; the inhibited CMA activity was partially rescued by a PI3K/AKT inhibitor, and the expression of megalin was down-regulated. Up-regulation of megalin expression by leptin played a synergistic role in osteoblast differentiation of rBMMSCs induced by 25(OH)D3; leptin promoted the expression of megalin by inhibiting the activity of CMA activity. Conclusions These studies indicate that leptin enhanced 25(OH)D3 stimulation of osteoblast differentiation of rBMMSCs by inhibiting CMA activity to increase megalin expression, and that PI3K/AKT signaling pathway is at least partially involved in the regulation of CMA activity and megalin expression.


Author(s):  
FAM Abo-Aziza ◽  
AA Zaki ◽  
AS Amer ◽  
RA Lotfy

Background: In vitro impact of dihydrotestosterone (DHT) and 17-estradiol (E2) in osteogenic differentiation of castrated rat bone marrow mesenchymal stem cells (rBMMSC) still need to be clarified. Materials and Methods: The viability, proliferation and density of cultured rBMMSC isolated from sham operated (Sham) and castrated (Cast) male rats were evaluated. rBMMSC were cultured with osteogenic differentiating medium (ODM) in the presence of DHT (5,10 nM) and E2 (10,100 nM). Osteogenesis was evaluated by alizarin red staining and measurement of calcium deposition and bone alkaline phosphatase (BALP) activity. Results: Population doubling (PD) of rBMMSC isolated from Cast rats was significantly lower (P<0.05) compared to that isolated from Sham rats. rBMMSC from Cast rats showed low scattered calcified nodule after culturing in ODM and did not cause a significant increase in calcium deposition and B-ALP activity compared to rBMMSCs from Sham rats. Exposure of rBMMSC isolated from Cast rats to DHT (5 nM) or E2 (10 nM) in ODM showed medium scattered calcified nodules with significantly higher (P<0.05) calcium deposition and B-ALP activity. Moreover, exposure of rBMMSC to DHT (10 nM) or E2 (100 nM) showed high scattered calcified nodules with higher (P<0.01) calcium deposition and B-ALP activity Conclusion: These results indicated that the presence of testes might participate in controlling the in vitro proliferation and osteogenic differentiation capacity of rBMMSCs. DHT and E2 can enhance the osteogenic capacity of rBMMSCs in a dose-dependent manner. Based on these observations, optimum usage of DHT and E2 can overcome the limitations of MSCs and advance the therapeutic bone regeneration potential in the future.


Author(s):  
Gang Xu ◽  
Zheng Ding ◽  
Hui-feng Shi

Abstract Background Bone marrow mesenchymal stem cells (BMMSCs) can be used for bone regeneration in the specified condition. Osteogenic differentiation of BMMSCs is controlled by microRNAs (miRNAs) and other factors. This study was aimed to identify the role and mechanism of miR-889 in regulating the osteogenic differentiation of BMMSCs. Methods Osteoporosis patients and normal control bone tissues were collected and used PCR techniques to identify the change of miR-889 and WNT7A. Moreover, the dynamic change of miR-889 and WNT7A during osteogenic differentiation of BMMSCs was also measured. Bioinformatic analysis was performed to identify the target genes and potential pathways of miR-889. Then, we constructed miR-889 mimic and inhibitor, ALP staining, ARS, osteoblastic-related protein, and Wnt β-catenin signaling pathway-related protein were also measured. WNT7A siRNA was also used to verify the function of miR-889. Results In the present study, we showed that miR-889 expression was upregulated in osteoporosis patients than healthy control. However, the miR-889 expression was downregulated during osteogenic differentiation. Bioinformatics analysis found that miR-889 targets 666 genes and mainly through Wnt β-catenin signaling pathway. Administrated miR-889 mimic, the ALP activity, and calcium deposition were decreased than the control group, while miR-889 inhibitor shown the opposite trend. And miR-889 could bind the 3′UTR of WNT7A. We further used WNT7A siRNA to explore the function of miR-889, and the results revealed that co-cultured with miR-889 inhibitor and WNT7A siRNA was associated with a reduction of ALP activity and calcium deposition and osteoblastic-related proteins than miR-889 inhibitor alone. Conclusion Our results revealed that miR-889 plays a negative role in inducing osteogenic differentiation of BMSCs through Wnt β-catenin signaling pathway.


2021 ◽  
Author(s):  
Ebrahim Rahmani-Moghadam ◽  
Tahereh Talaei-Khozani ◽  
Vahideh Zarrin ◽  
Zahra Vojdani

Abstract Background: Hydroxyapatite (HA) can be loaded by some osteogenic inducing agents such as thymoquinone (TQ) and alginate. This study was performed to investigate the effect of TQ loading into HA/alginate scaffolds on osteogenic differentiation capability of mesenchymal stem cells.Methods: HA scaffolds were fabricated by casting and sintering method and impregnated by TQ containing alginate. The stem cells were loaded onto the scaffolds and induced to differentiate into osteoblasts. Alkaline Phosphatase (ALP) activity, Alizarin Red S, Real-Time qRT-PCR, and MTT assessments were done. Finally, the cells were examined with a light microscope, confocal microscope, and SEM.Results: The results showed that the presence of the alginate decelerates the degradation rate and reinforces the mechanical strength. while the presence of TQ had no significant influence on physical and mechanical properties of the HA/alginate scaffolds, it led to a significant increase in ALP activity and expression of collagen, osteopontin, and osteocalcin at early phase of differentiation. Also, TQ administration had no impact on calcium deposition and proliferation as well as bone-marker expression at long term differentiation.Conclusion: TQ accelerates the differentiation of the stem cells into the osteoblasts without changing the properties of the scaffolds, and the HA/alginate/TQ scaffold can be used as a scaffold with osteogenic properties in bone tissue engineering applications.


Author(s):  
Bingkun Zhao ◽  
Qian Peng ◽  
Enoch Hin Lok Poon ◽  
Fubo Chen ◽  
Rong Zhou ◽  
...  

BackgroundLeonurine, a major bioactive component from Herba leonuri, has been shown to exhibit anti-inflammatory and antioxidant effects. The aim of this study was to investigate the effect of leonurine on bone marrow-derived mesenchymal stem cells (BMSCs) as a therapeutic approach for treating osteoporosis.Materials and MethodsRat bone marrow-derived mesenchymal stem cells (rBMSCs) were isolated from 4-weeks-old Sprague–Dawley rats. The cytocompatibility of leonurine on rBMSCs was tested via CCK-8 assays and flow cytometric analyses. The effects of leonurine on rBMSC osteogenic differentiation were analyzed via ALP staining, Alizarin red staining, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot. Additionally, autophagy-related markers were examined via qRT-PCR and Western blot analyses of rBMSCs during osteogenic differentiation with leonurine and with or without 3-methyladenine (3-MA) as an autophagic inhibitor. Finally, the PI3K/Akt/mTOR signaling pathway was evaluated during rBMSC osteogenesis.ResultsLeonurine at 2–100 μM promoted the proliferation of rBMSCs. ALP and Alizarin red staining results showed that 10 μM leonurine promoted rBMSC osteoblastic differentiation, which was consistent with the qRT-PCR and Western blot results. Compared with those of the control group, the mRNA and protein levels of Atg5, Atg7, and LC3 were upregulated in the rBMSCs upon leonurine treatment. Furthermore, leonurine rescued rBMSC autophagy after inhibition by 3-MA. Additionally, the PI3K/AKT/mTOR pathway was activated in rBMSCs upon leonurine treatment.ConclusionLeonurine promotes the osteoblast differentiation of rBMSCs by activating autophagy, which depends on the PI3K/Akt/mTOR pathway. Our results suggest that leonurine may be a potential treatment for osteoporosis.


2022 ◽  
Vol 12 (4) ◽  
pp. 794-799
Author(s):  
Le Chang ◽  
Wei Duan ◽  
Chuang Wang ◽  
Jian Zhang

This study was to determine whether microRNA (miRNA)-126 regulates osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Rat BMSCs were extracted and stimulated for osteogenic differentiation. Functional experiments were conducted to assess miR-126’s impact on BMSCs differentiation. Western blot and RT-qPCR determined miR-126 expression. ALP activity detection and alizarin red staining detection were also performed. After osteogenic differentiation of BMSCs, miR-126 expression was gradually decreased over time. Overexpression of miR-26 decreased ALP activity, Notch signaling activity as well as declined Runx2 expression and calcium Salt nodules after treatment. Importantly, we found that Smad4 serves as a target of miR-126 while upregulation of the miRNA was accompanied with the decreased Smad4 protein expression without affecting the Smad4 mRNA level. In conclusion, miR-126 restrains osteogenic differentiation through inhibition of SMAD4 signaling, providing a novel insight into the mechanism.


2018 ◽  
Vol 51 (3) ◽  
pp. 1087-1102 ◽  
Author(s):  
Lijun Duan ◽  
He Zhao ◽  
Yang Xiong ◽  
Xiangsheng Tang ◽  
Yongdong Yang ◽  
...  

Background/Aims: Osteoporosis is a bone metabolic disease characterized by a systemic impairment of bone mass, which results in increased propensity of fragility fractures. A reduction in the differentiation of MSCs into osteoblasts contributes to the impaired bone formation observed in osteoporosis. Mesenchymal stem cells (MSCs) are induced to differentiate into preosteoblasts, which are regulated by the signaling cascades initiated by the various signals, including miRNAs. miR-16-2* is a newly discovered miRNA that participates in diagnosis and prognosis of hepatocellular carcinoma, cervical cancer and chronic lymphocytic leukemia. However, the effect of miR-16-2* on the regulation of osteoblast differentiation and the mechanism responsible are still unclear. Here we discuss the contribution of miR-16-2* to osteoporosis, osteoblast differentiation and mineralization. Methods: The expression pattern of miR-16-2* during osteogenesis or in osteoporosis bone samples was validated by quantitative real-time PCR (qRT-PCR). The human bone marrow mesenchymal stem cells (hBMSCs) were induced to differentiate into osteoblasts by osteogenic induced medium containing dexamethasone, ascorbate-2-phosphat, beta-glycerophosphate and vitamin-D3. The target genes of miR-16-2* were predicted by TargetScan and PicTar. The mRNA and protein levels of osteogenic key markers were detected using qRT-PCR or western blot respectively. The WNT signal activity was analyzed by TOP/FOP reporter assay. Results: The expression of miR-16-2* in patient bone tissue with osteoporosis was negatively correlated with bone formation related genes. During osteoblast differentiation process, the expression of miR-16-2* was significantly decreased. Upregulation of miR-16-2* in hBMSCs impaired the osteogenic differentiation while the downregulation of miR-16-2* increased this process. Upregulation the expression of miR-16-2* could also block the WNT signal pathway by directly target WNT5A. Furthermore, knockdown of miR-16-2* could promote the activation of RUNX2, possibly by lifting the inhibitory effect of miR-16-2* on WNT pathway. Conclusion: Taken together, we report a novel biological role of miR-16-2* in osteogenesis through regulating WNT5A response for the first time. Our data support the potential utilization of miRNA-based therapies in regenerative medicine.


2017 ◽  
Vol 60 (6) ◽  
pp. 326-334 ◽  
Author(s):  
Carla Martins Kaneto ◽  
Patrícia S. Pereira Lima ◽  
Karen Lima Prata ◽  
Jane Lima dos Santos ◽  
João Monteiro de Pina Neto ◽  
...  

2020 ◽  
Vol 10 (12) ◽  
pp. 1865-1870
Author(s):  
Yang Ying ◽  
Binghao Zhao ◽  
Wei Qian ◽  
Li Xu

Bone marrow mesenchymal stem cells (BMSCs) have self-renewal potential with multi-directional differentiation. Progranulin prevents bone degradation, inhibits inflammation and protects bone tissue. However, the role of Progranulin in osteoporotic BMSCs is unclear. Osteoporosis (OP) rat models were prepared by ovarian removal and treated with different doses (5 and 10 μM) of Progranulin followed by analysis of BMP-2 level by ELISA, bone mineral density and ALP activity. OP rat BMSCs were isolated and assigned into control group and Progranulin group followed by analysis of Progranulin level by ELISA, cell proliferation by MTT assay, RUNX2 and COL1A1 mRNA level by Real time PCR, and PI3K/Akt/PPARγ signaling protein level by Western blot. Progranulin treatment of OP rats dose-dependently increased BMP-2 expression, bone density and ALP activity. Compared with OP group, there were significant differences (P <0.05). Progranulin expression and BMSCs proliferation was increased, and RUNX2 and COL1A1 mRNA expression was elevated in Progranulin-treated OP group along with increased PI3K/Akt expression and decreased PPARγ protein expression. Compared with OP group, the difference was statistically significant, and the change was more significant with increasing concentration (P <0.05). Progranulin promotes BMSCs osteogenic differentiation and proliferation by regulating PI3K/Akt/PPARγ signaling pathway, which is beneficial for OP rats’ bone synthesis.


2021 ◽  
Vol 11 (5) ◽  
pp. 957-962
Author(s):  
Ainiwaerjiang Damaola ◽  
Maerdan Aierken ◽  
Mieralimu Muertizha ◽  
Abudouaini Abudoureheman ◽  
Haishan Lin ◽  
...  

We aimed to explore the effects of rat bone marrow mesenchymal stem cells (BMSCs) on osteogenic differentiation via analyzing miR-3148 expression in patients with osteoporosis. Realtime quantitative PCR was conducted for assessing microRNA-3148 expression. BMSCs from SD rats were transfected with microRNA-3148 mimics and microRNA-3148 inhibitor via liposomal trans-fection method utilizing Lipo2000, followed by analysis of microRNA-3148 level. After 10-days of osteogenic differentiation induction, alkaline phosphatase (ALP) staining and alizarin red (ARS) staining were done to investigate the osteogenic differentiation potential. Simultaneously, qRT-PCR measured the expression of osteogenesis marker genes (BMP and Runx2) in each group. qRT-PCR analysis revealed a high expression of miR-3148 in the bone tissue and the serum samples from patients with osteoporosis in comparison with healthy individuals. In addition, miRNA-3148 mimics could retard the osteogenic differentiation of BMSCs, while microRNA-3148 inhibitor could prompt the procedure. MicroRNA-3148 was highly expressed in the skeletal tissues and the serum samples from patients with osteoporosis and it could restrain the differentiation of BMSCs into osteoblasts, suggesting that it might be a novel therapeutic target for treating osteoporosis.


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