scholarly journals Nrf2 Activation Is Involved in Cyclic Mechanical Stress-Stimulated Osteogenic Differentiation in Periodontal Ligament Stem Cells via PI3K/Akt Signaling and HO1-SOD2 Interaction

Author(s):  
Xun Xi ◽  
Zixuan Li ◽  
Hong Liu ◽  
Shuai Chen ◽  
Dongxu Liu

Nuclear factor erythroid-2-related factor-2 (Nrf2), the major transcriptional regulator in antioxidant response and cellular defense, had the vital effect on regulating osteogenic differentiation. Our previous study revealed that Nrf2 activation was involved in cyclic mechanical stress-stimulated osteogenic differentiation in the human periodontal ligament stem cells (PDLSCs). However, the mechanisms of Nrf2 underlying this process remained unclear. The goal of the study was to explore the mechanisms of Nrf2 in PDLSCs during cyclic mechanical stress-stimulated osteogenic differentiation via the tandem mass tag (TMT)-based liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis. And we applied tert-Butylhydroquinone (t-BHQ), the Nrf2 activator, to the orthodontic rats and detected the expression levels of the osteogenesis markers by immunohistochemistry (IHC) staining. Our results showed that Nrf2 activation in PDLSCs was involved in cyclic mechanical stress-stimulated osteogenic differentiation via phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) pathway. The protein-protein interaction between Akt and Nrf2 was detected. And the protein-protein interaction between heme oxygenase 1 (HO1) and superoxide dismutase 2 (SOD2), the downstream antioxidants of Nrf2, was associated with cyclic mechanical stress-stimulated osteogenic differentiation. T-BHQ enhanced the expression levels of the osteogenesis markers in orthodontic rats. Nrf2 might possess the potential to be a feasible molecular target in orthodontics.

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Lihua Yin ◽  
Wenxiao Cheng ◽  
Zishun Qin ◽  
Hongdou Yu ◽  
Zhanhai Yu ◽  
...  

This study is to explore the osteogenesis potential of the human periodontal ligament stem cells (hPDLSCs) induced by naringin in vitro and in vitro. The results confirmed that 1 μM naringin performs the best effect and a collection of bone-related genes (RUNX2,COL1A2, OPN, and OCN) had significantly higher expression levels compared to the control group. Furthermore, a typical trabecular structure was observed in vivo, surrounded by a large amount of osteoblasts. These results demonstrated that naringin, at a concentration of 1 μM, can efficiently promote the proliferation and differentiation of hPDLSCs both in vitro and in vivo.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8663
Author(s):  
Miaomiao Zheng ◽  
Fuping Zhang ◽  
Wenguo Fan ◽  
Liulin Jiang ◽  
Jingzhou Li ◽  
...  

N-Acetyl-5-methoxytryptamine (melatonin, MT) at pharmacological concentrations promotes the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells; however, its role at physiological concentrations (1 pM–10 nM) remains unclear. We explored the effects of 1 pM–1 µM MT on the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and its underlying mitochondrial dynamics-mediated mechanisms. T he PDLSC phenotype was detected by flow cytometry and evaluated for three-line differentiation. Alkaline phosphatase activity assay and Alizarin red staining were used to evaluate osteogenic differentiation. Osteogenesis-related gene and protein expression levels were measured by quantitative reverse transcription -polymerase chain reaction and western blotting. Mitochondrial function assays were performed using reactive oxygen species, ATP and NAD+/NADH kits and molecular mechanisms of mitochondrial dynamics-related proteins were assessed by western blotting. Our results have shown that physiological MT concentrations induced differentiation of hPDLSCs and down-regulated osteopontin (OPN) and osteocalcin (OCN) expression levels, which were restored or even up-regulated by 1 µM MT (lowest pharmacological concentration). Compared to the osteogenic induction alone, this treatment decreased the intracellular ATP content, whereas the intracellular reactive oxygen species level and NAD+/NADH ratio were increased. Mitochondrial function- and dynamics-related protein expression levels were consistent with those of osteogenic genes following osteogenic induction and MT treatment of hPDLSCs at various physiological concentrations. Physiological MT concentrations inhibited the osteogenic differentiation of hPDLSCs and simultaneously altered mitochondrial function. These findings provide insights into the stem cell tissue engineering and functions of MT.


2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Qian Li ◽  
Xiwen Sun ◽  
Yunyi Tang ◽  
Yanan Qu ◽  
Yanheng Zhou ◽  
...  

Abstract Despite the ubiquitous mechanical cues at both spatial and temporal dimensions, cell identities and functions are largely immune to the everchanging mechanical stimuli. To understand the molecular basis of this epigenetic stability, we interrogated compressive force-elicited transcriptomic changes in mesenchymal stem cells purified from human periodontal ligament (PDLSCs), and identified H3K27me3 and E2F signatures populated within upregulated and weakly downregulated genes, respectively. Consistently, expressions of several E2F family transcription factors and EZH2, as core methyltransferase for H3K27me3, decreased in response to mechanical stress, which were attributed to force-induced redistribution of RB from nucleoplasm to lamina. Importantly, although epigenomic analysis on H3K27me3 landscape only demonstrated correlating changes at one group of mechanoresponsive genes, we observed a genome-wide destabilization of super-enhancers along with aberrant EZH2 retention. These super-enhancers were tightly bounded by H3K27me3 domain on one side and exhibited attenuating H3K27ac deposition and flattening H3K27ac peaks along with compensated EZH2 expression after force exposure, analogous to increased H3K27ac entropy or decreased H3K27ac polarization. Interference of force-induced EZH2 reduction could drive actin filaments dependent spatial overlap between EZH2 and super-enhancers and functionally compromise the multipotency of PDLSC following mechanical stress. These findings together unveil a specific contribution of EZH2 reduction for the maintenance of super-enhancer stability and cell identity in mechanoresponse.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Tingting Meng ◽  
Ying Zhou ◽  
Jingkun Li ◽  
Meilin Hu ◽  
Xiaomeng Li ◽  
...  

Background and Objective. This study investigated the effects and underlying mechanisms of azithromycin (AZM) treatment on the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) after their stimulation with TNF-α in vitro. Methods. PDLSCs were isolated from periodontal ligaments from extracted teeth, and MTS assay was used to evaluate whether AZM and TNF-α had toxic effects on PDLSCs viability and proliferation. After stimulating PDLSCs with TNF-α and AZM, we analyzed alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red staining to detect osteogenic differentiation. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect the mRNA expression of osteogenic-related genes, including RUNX2, OCN, and BSP. Western blotting was used to measure the NF-κB signaling pathway proteins p65, phosphorylated p65, IκB-α, phosphorylated IκB-α, and β-catenin as well as the apoptosis-related proteins caspase-8 and caspase-3. Annexin V assay was used to detect PDLSCs apoptosis. Results. TNF-α stimulation of PDLSCs decreased alkaline phosphatase and alizarin red staining, alkaline phosphatase activity, and mRNA expression of RUNX2, OCN, and BSP in osteogenic-conditioned medium. AZM enhanced the osteogenic differentiation of PDLSCs that were stimulated with TNF-α. Western blot analysis showed that β-catenin, phosphorated p65, and phosphorylated IκB-α protein expression decreased in PDLSCs treated with AZM. In addition, pretreatment of PDLSCs with AZM (10 μg/ml, 20 μg/ml) prevented TNF-α-induced apoptosis by decreasing caspase-8 and caspase-3 expression. Conclusions. Our results showed that AZM promotes PDLSCs osteogenic differentiation in an inflammatory microenvironment by inhibiting the WNT and NF-κB signaling pathways and by suppressing TNF-α-induced apoptosis. This suggests that AZM has potential as a clinical therapeutic for periodontitis.


Sign in / Sign up

Export Citation Format

Share Document