CHNQD-00603 Promotes Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells by the miR-452-3p-Mediated Autophagy Pathway

Role of in-situ electrical stimulation on early-stage mineralization and in-vitro osteogenesis of electroactive bioactive glass composites

Bioactive glass (BAG) has emerged as an effective bone graft substitute due to its diverse qualities of biocompatibility, bioactivity, osteoblast adhesion and enhanced revascularization. However, inferior osteogenic capacity of BAG compared to autologous bone grafts continues to limiting it's wide-spread clinical applications towards repairing of bone fractures and healing. In this study, we have fabricated BAG composites with 0.5 to 2 wt% bismuth ferrite (BF, a multiferroic material) with an aim to generate in-situ electrical charges pertinent to early-stage bone regeneration thus mimicking natural bone, which is a piezoelectric material. The fabricated BAG composites were characterised in terms of microstructures, phase analysis, remanent polarization, wettability and subsequently evaluated for in vitro cell proliferation and osteogenesis with and without magnetic field exposure (200 mT, 30 min./day). Pre-osteoblast cells from mice (MC3T3-E1) seeded on these composites exhibited excellent cell growth without any cytotoxicity, which is further supported by FITC/DAPI staining and a live/dead assay. The results of Alizarin Red S assay and increased levels of Alkaline Phosphatase (ALP) activity, at 21 days of culture, suggest that the BAG-BF composites promote in vitro osteogenic differentiation of pre-osteoblast cells. The enhanced osteogenesis of BAG-BF composites was also confirmed through qRT-PCR analysis, which showed rapid upregulation of osteoblastogenic specific genes namely RunX-2, Collagen-1, Bone Sialo Protein, and ALP after 21 days. Additionally, the osteogenic differentiation was assessed by the Western Blot technique, which revealed significantly higher band intensity of osteogenic markers in BAG-1.5 BF and BAG-2 BF composites than pure BAG. These findings clearly demonstrate that in-situ electrical stimulation and osteoconductive capacity of BF reinforced BAG composites have positive impact on osteoblast cell development, bone formation, and healing.

miR-16a-5p antagonizes FGF-2 in ligamentogenic differentiation of MSC: a new therapeutic perspective for tendon regeneration

With the increasing demand for exercise, the population of patients with ankle sprain to anterior talofibular ligament injury has the characteristics of a large base and high requirements for returning to sports, and how to promote the repair of damaged ligaments from a microscopic perspective is an urgent problem to be solved. In many studies, human amniotic mesenchymal stem cells have strong differentiation ability, and can be induced to continuously differentiate into ligament cells to achieve the purpose of repairing damaged ligaments. Human amniotic stem cells were extracted and cultured from human amniotic tissues, evaluated by cell identification and other techniques, and evaluated into ligament differentiation by toluidine blue, alizarin red, oil red O staining and detection of ligament cell differentiation, protein detection by Western blot, mRNA level by qPCR, and finally, the targeted binding relationship between miR-16a-5p and mRNA FGF2 was verified by double luciferase reporter assay. The expression of collagen type 1 (COL 1), collagen type 3 (COL3), SCX and MKX was increased by overexpression of mRNA FGF2, respectively, and miR-16a-5p had a targeted effect on FGF2 and regulated the ligamentous differentiation of human amniotic mesenchymal stem cells. We found that the regulatory effect of overexpressed mRNA FGF2 on mesenchymal stem cells could be inhibited by up-regulation of miR-16a-5p, while the knockdown of FGF2 could reverse the regulatory effect of miR-16a-5p inhibition on ligament-forming differentiation of human amniotic mesenchymal stem cells. In this study, we discovered the existence of the miR-16a-5p-FGF2 axis in human amniotic mesenchymal stem cells, and the differentiation of human amniotic mesenchymal stem cells into ligamentous cells can be regulated by regulating various links in this axis.

Agaricus blazei Murrill Polysaccharide Attenuates Periodontitis via H2 S/NRF2 Axis-Boosted Appropriate Level of Autophagy in PDLCs

SCOPE

Periodontitis is one of the most prevalent chronic inflammatory diseases with impaired autophagy. Agaricus blazei Murrill polysaccharide (ABMP) shows beneficial effects in various inflammatory diseases. However, whether ABMP is involved in autophagy regulation and periodontitis attenuation remains to be elucidated.

METHODS AND RESULTS

This study firstly shows the dynamic changes in inflammatory and autophagy levels in silk ligature periodontitis model. Then the positive regulation effect of autophagy on inflammation and its vital role in ABMP inhibiting PDLCs inflammatory response are testified in LPS-treated PDLCs. Secondly, the Micro-CT, quantitative RT-PCR, Western Blot, TRAP, and immunofluorescence staining analysis are performed to assess the effects of ABMP on periodontitis and autophagy. The data show the augmented autophagy and alleviated gingival recession, inflammatory cell infiltration, alveolar bone resorption, and reduced osteoclasts in periodontitis by ABMP treatment. Further experiments using chemical inhibitors demonstrate the vital role of H2 S/NRF2 axis in ABMP-induced appropriate level of autophagy augmentation against periodontitis.

CONCLUSIONS

Collectively, the findings not only reveal the unrecognized capacity and mechanism of ABMP as an effective and potential dietary intake against periodontitis, but also suggest the possibility for ABMP to be used in the treatment of other autophagy-related diseases.

Osteogenic effects of rapamycin on bone marrow mesenchymal stem cells via inducing autophagy

BACKGROUND

While autophagy is essential for stem cells' self-renewal and differentiation, its effect on bone marrow mesenchymal stem cells (BMSCs) remains unclear. This study aimed to investigate the interaction between autophagy and osteogenic differentiation using rapamycin (RAPA), a classical autophagy agonist with osteo-regulatory effects.

METHODS

Rat BMSC's autophagy was analyzed after osteoinduction (0, 7, 14, and 21 d) by western blotting, immunofluorescence, and real-time quantitative polymerase chain reaction (RT-qPCR). In addition, we evaluated osteogenic differentiation using alizarin red staining, alkaline phosphatase assays, and RT-qPCR/Western blotting quantification of bone sialoprotein, type 1 collagen, alkaline phosphatase, osteopontin, and Runt-related transcription factor 2 mRNA and protein levels.

RESULTS

The BMSC's basal autophagy level gradually decreased during osteogenic differentiation with a decrease in BECN1 level and the lipidated (LC3-II) to unlipidated (LC3-I) microtubule-associated protein 1 light chain 3 ratio and an increase in the expression of selective autophagic target p62. In contrast, it increased with increasing RAPA concentration. Furthermore, while 2 nM RAPA promoted BMSC osteogenic differentiation on days 7 and 14, 5 nM RAPA inhibited osteogenesis on days 14 and 21. Inhibition of autophagy by the inhibitor 3-methyladenine could impair RAPA's osteogenesis-enhancing effect on BMSCs.

CONCLUSIONS

The BMSC's basal autophagy level decreased over time during osteogenic differentiation. However, an appropriate RAPA concentration promoted BMSC osteogenic differentiation via autophagy activation.

Aerophobin-1 from the Marine Sponge Aplysina aerophoba Modulates Osteogenesis in Zebrafish Larvae

Longer life expectancy has led to an increase in efforts directed to the discovery of new healing agents for disorders related to aging, such as bone diseases. Harboring an incredible variety of bioactive metabolites, marine organisms are standing out as fruitful sources also in this therapeutic field. On the other hand, the in vivo zebrafish model has proven to be an excellent low-cost screening platform for the fast identification of molecules able to regulate bone development. By using zebrafish larvae as a mineralization model, we have thus evaluated the effects of the crude acetonic extract from the marine sponge Aplysina aerophoba and its bromotyrosine components on bone development. Obtained results led to the selection of aerophobin-1 (1) as a promising candidate for applications in regenerative medicine, paving the way for the development of a novel therapeutic option in osteoporosis treatment.