Betaine regulates adipogenic and osteogenic differentiation of hAD-MSCs

Betaine enhances SCAPs chondrogenic differentiation and promotes cartilage repair in TMJOA through WDR81

BACKGROUND

The cartilage tissue regeneration mediated with mesenchymal stem cells (MSCs) is considered as a viable strategy for temporomandibular joint osteoarthritis (TMJOA). Betaine has been confirmed to modulate the multidirectional differentiation of MSCs, while its effect on chondrogenic differentiation of Stem Cells from the Apical Papilla (SCAPs) is unknown. Here, we explored the effects and underlying mechanisms of betaine on chondrogenic differentiation of SCAPs.

METHODS

Betaine was added for SCAPs chondrogenic induction. The chondrogenic differentiation potential was assessed using Alcian Blue staining, Sirius Red staining and the main chondrogenic markers. In vivo cartilage regeneration effects were evaluated by the rat TMJOA model. RNA-sequencing and biological analyses were performed to select target genes and biological processes involved. The mechanism betaine acts on chondrogenic differentiation of SCAPs was further explored.

RESULTS

Betain-treated SCAPs demonstrated stronger cartilage regeneration in vitro and promoted cartilage repair of TMJOA in vivo. Betaine enhanced the expression of WDR81 in SCAPs during chondrogenesis. WDR81 overexpression promoted chondrogenic differentiation of SCAPs, while WDR81 depletion inhibited chondrogenic differentiation. In addition, both betaine treatment and WDR81 overexpression reduced intracellular reactive oxygen species levels and increased mitochondrial membrane potential in SCAPs.

CONCLUSION

Betaine promotes SCAPs chondrogenic differentiation and provided an effective candidate for TMJOA treatment. WDR81 may serve as the potential drug target through mitophagy.

Sex differences in the association between dietary choline intake and total bone mineral density among adolescents aged 12-19 in the United States

Background

While prior research has established a correlation between dietary choline intake and bone density in the elderly, the relationship in adolescents remains ambiguous. This study seeks to examine the association between dietary choline intake and bone density in American adolescents.

Methods

Data from the National Health and Nutrition Examination Survey (NHANES) for 2005 to 2018 were used in this study, encompassing participants aged 12-19 years. The relationship between dietary choline intake and bone density was assessed using multivariate linear regression models and restricted cubic spline (RCS) models. Subgroup analyses were also performed to investigate differences across various subgroups.

Results

3,800 participants with an average age of 15 years were included in this study. After adjusting for relevant confounding factors, a positive correlation was observed between dietary choline intake and total bone density in adolescents (95% CI: 0.03-0.17, p = 0.010). Gender-specific analysis indicated a significant positive correlation between dietary choline intake and total bone density in males (95% CI: 0.07-0.23, p < 0.001), while no significant correlation was found in females (95% CI: -0.19 to 0.09, p = 0.500). The stratified analysis revealed that the positive association was more pronounced in males and non-Hispanic whites (interaction p < 0.05). The restricted cubic spline model demonstrated a linear positive correlation between dietary choline intake and total bone density.

Conclusion

This study demonstrates that dietary choline intake levels are positively correlated with bone density in adolescents, with this association being specific to males.

Oncostatin M promotes osteogenic differentiation of tendon-derived stem cells through the JAK2/STAT3 signalling pathway

PURPOSE

Oncostatin M (OSM) is involved in the regulation of osteogenic differentiation and has a major role in the development of heterotopic ossification. The role of OSM in osteogenic differentiation of tendon-derived stem cells (TDSCs) and its mechanism have not been reported. This study aim to investigate the role of OSM in osteogenic differentiation of TDSCs and study the mechanism.

METHODS

TDSCs were differentiated in osteogenic differentiation medium for 7 days. Recombinant OSM was added to the osteogenic differentiation medium for 7 and 14 days. The effect of Janus kinase 2 (JAK2) inhibitor AZD1480 and signal transducer and activator of transcription 3 (STAT3) inhibitor stattic in the presence of recombinant OSM on osteogenic differentiation of TDSCs was examined after differentiation for 7 and 14 days. Alkaline phosphatase and alizarin red staining were used to assess the effects on early and mid-stage osteogenic differentiation, respectively. Western blotting and qPCR were used to assess the expression of receptor and signalling pathway-related proteins and osteogenic marker genes, respectively.

RESULTS

TDSCs were successfully induced to differentiate into osteoblasts. Recombinant OSM promoted osteogenic differentiation of TDSCs to early and mid-stages. After addition of AZD1480 or stattic, decreased alkaline phosphatase and alizarin red staining were observed in the early and mid-stages of osteogenic differentiation. Additionally, decreased expression of receptor and pathway-related proteins, and osteogenic genes was found by western blotting and qPCR, respectively.

CONCLUSION

OSM promotes osteogenic differentiation of TDSCs and the JAK2/STAT3 signalling pathway plays an important role.

Mechanism of Bazi Bushen capsule in delaying the senescence of mesenchymal stem cells based on network pharmacology and experimental validation

Ageing is becoming an increasingly serious problem; therefore, there is an urgent need to find safe and effective anti-ageing drugs.

Aims

To investigate the effects of Bazi Bushen capsule (BZBS) on the senescence of mesenchymal stem cells (MSCs) and explore its mechanism of action.

Methods

Network pharmacology was used to predict the targets of BZBS in delaying senescence in MSCs. For in vitro studies, MSCs were treated with D-gal, BZBS, and NMN, and cell viability, cell senescence, stemness-related genes, and cell cycle were studied using cell counting kit-8 (CCK-8) assay, SA-β-galactosidase (SA-β-gal) staining, Quantitative Real-Time PCR (qPCR) and flow cytometry (FCM), respectively. Alkaline phosphatase (ALP), alizarin red, and oil red staining were used to determine the osteogenic and lipid differentiation abilities of MSCs. Finally, the expression of senescence-related genes and cyclin-related factors was detected by qPCR and western blotting.

Results

Network pharmacological analysis suggested that BZBS delayed cell senescence by interfering in the cell cycle. Our in vitro studies suggested that BZBS could significantly increase cell viability (P < 0.01), decrease the quantity of β-galactosidase+ cells (P < 0.01), downregulate p16 and p21 (P < 0.05, P < 0.01), improve adipogenic and osteogenic differentiation, and upregulate Nanog, OCT4 and SOX2 genes (P < 0.05, P < 0.01) in senescent MSCs. Moreover, BZBS significantly reduced the proportion of senescent MSCs in the G0/G1 phase (P < 0.01) and enhanced the expression of CDK4, Cyclin D1, and E2F1 (P < 0.05, P < 0.01, respectively). Upon treatment with HY-50767A, a CDK4 inhibitor, the upregulation of E2F1 was no longer observed in the BZBS group.

Conclusions

BZBS can protect MSCs against D-gal-induced senescence, which may be associated with cell cycle regulation via the Cyclin D1/CDK4/E2F1 signalling pathway.

Biomimetic Intrafibrillar Mineralization of Native Tendon for Soft-Hard Interface Integration by Infiltration of Amorphous Calcium Phosphate Precursors

Soft and hard tissues possess distinct biological properties. Integrating the soft-hard interface is difficult due to the inherent non-osteogenesis of soft tissue, especially of anterior cruciate ligament and rotator cuff reconstruction. This property makes it difficult for tendons to be mineralized and integrated with bone in vivo. To overcome this challenge, a biomimetic mineralization strategy is employed to engineer mineralized tendons. The strategy involved infiltrating amorphous calcium phosphate precursors into collagen fibrils, resulting in hydroxyapatite deposition along the c-axis. The mineralized tendon presented characteristics similar to bone tissue and induced osteogenic differentiation of mesenchymal stem cells. Additionally, the interface between the newly formed bone and tendon is serrated, suggesting a superb integration between the two tissues. This strategy allows for biomineralization of tendon collagen and replicating the hallmarks of the bone matrix and extracellular niche, including nanostructure and inherent osteoinductive properties, ultimately facilitating the integration of soft and hard tissues.