Therapeutic effects of bone mesenchymal stem cells on oral and maxillofacial defects: a novel signaling pathway involving miR-31/CXCR4/Akt axis

Skeleton-derived extracellular vesicles in bone and whole-body aging: From mechanisms to potential applications

The skeleton serves as a supportive and protective organ for the body. As individuals age, their bone tissue undergoes structural, cellular, and molecular changes, including the accumulation of senescent cells. Extracellular vesicles (EVs) play a crucial role in aging through the cellular secretome and have been found to induce or accelerate age-related dysfunction in bones and to contribute further via the circulatory system to the aging of phenotypes of other bodily systems. However, the extent of these effects and their underlying mechanisms remain unclear. Therefore, this paper attempts to give an overview of the current understanding of age-related alteration in EVs derived from bones. The role of EVs in mediating communications among bone-related cells and other body parts is discussed, and the significance of bones in the whole-body aging process is highlighted. Ultimately, it is hoped that gaining a clearer understanding of the relationship between EVs and aging mechanisms may serve as a basis for new treatment strategies for age-related degenerative diseases in the skeleton and other systems.

C-X-C Chemokine Receptor Type 4 (CXCR-4) Functionally-Selective Allosteric Agonist ATI2341 Promotes the Recovery of Uterosacral Ligament

This study intends to assess whether CXCR4 functionally-selective allosteric agonist ATI2341 recovers uterosacral ligament. The 50 female rats were assigned into five groups including A group (normal healthy rats), B group (rats with uterine ligament injury), C group (injury rats treated with UC-MSCs cells), D group (treated with ATI2341); E group (treated with UC-MSCs cells and ATI2341) followed by analysis of uterus pathological changes by H&E staining and the expression of CD44, CD90, CXCR4, and SDF-1 by Western Blot or PT-PCR. There was regular and pyknotic fibrillar connective tissue and few small vessels in A group without infiltration of inflammatory cells. However, B group showed infiltration of inflammatory cells with few fibroblasts of fibrous tissue. The quantity of infiltration of inflammatory cells in C group and D group was less than that in B group with few visible new-born vessels. The improvement of pathological condition in uterus tissue in E group was the most among treatment groups. The number of wavy fiber was increased gradually and fibrillar connective tissue was changed into dense with elevated new-born vessels in ligament. The expression CD44, CD90, CXCR4 and SDF-1 was upregulated effectively by ATI2341. In conclusion, ATI2341 can upregulate the expression of CD44, CD90, CXCR4 and SDF-1 and promote the recovery of uterine ligament in rats, indicating that it might be a new approach for the treatment of uterine ligament.

MiR-31 improves spinal cord injury in mice by promoting the migration of bone marrow mesenchymal stem cells

Background

Stem cell transplantation therapy is a potential approach for the repair of spinal cord injuries and other neurodegenerative diseases, but its effectiveness is hampered by the low rate of targeted migration of cells to the area of injury. The aim of this study was to investigate the effects of miR-31 on the migration of bone marrow mesenchymal stem cells (BMSCs) and the regulation of MMP-2 and CXCR4 expression in vitro and in vivo.

Methods

eGFP-expressing BMSCs were isolated and cultured for subsequent experiments. The experiments were divided into three groups: control group, miR-31agomir group, and miR-31antagomir group. Proliferation was analyzed using CCK-8 and flow cytometry; cell migration in vitro was analyzed using wound-healing and transwell assays. The mouse SCI model was prepared by the impact method, and cells were transplanted (3 groups, 12 per group). Relevant inflammatory factors were detected by ELISA. The BMS score was used to evaluate the functional recovery of the mouse spinal cord and the frozen section was used to analyze the cell migration ability in vivo. The in vitro and in vivo expression levels of MMP-2 and CXCR4 were evaluated by Western blot and immunohistochemical staining.

Results

In vitro experiments showed that cells in the miR-31agomir group exhibited enhanced cell proliferation (P<0.05, P<0.001) and migration (P<0.001) and upregulated protein expression levels of CXCR4 (P<0.01) and MMP-2 (P<0.001) compared with cells in the control group. The results of in vivo experiments showed that the expression of pro-inflammatory factors was reduced after cell transplantation treatment. Cells in the miR-31agomir group showed enhanced cell-targeted migration ability (P<0.001), improved the function of damaged tissues (P<0.001), and upregulated CXCR4 and MMP-2 expression compared to the control group (P<0.001).

Conclusion

Our experiment demonstrated that miR-31 could promote the migration of BMSCs and miR-31 could repair and improve the function of damaged tissues in SCI.

Co-Culture of Bone Marrow Mesenchymal Stem Cells Regulates the Fibrotic Response of Endometrial Stromal Cells

This study explored the protective effects and mechanisms of bone marrow mesenchymal stem cells (BMSCs) on the fibrotic response of endometrial stromal cells. The endometrial cells were isolated from intrauterine adhesions (IUA) patients and assigned into control group, TGF-β1 group, BMSC group which was co-cultured with BMSCs in presence of TGF-β1; Exo group (treated with BMSCs-originated exosomes); Exo-inhibitor group (treated with exosome-specific inhibitors) followed by analysis of α-SMA and Vimentin level, cell viability and expression of TGFBR2, TGFβ-1, Fibronectin (FN), α-SMA, Collagen 1α1 (Col1a1), Smad2/3 and p-Smad2/3. After TGF-β1 treatment, cells exhibited higher expression of p-Smad2/3, TGFBR2, FN, TGF-SMA and COL1A1 along with reduced cell proliferation. However, BMSCs-originated exosomes or co-culture with BMSCs reversed these changes which could be inverted by exosome-specific inhibitors. In conclusion, BMSCs-originated exosomes and BMSCs exerted an anti-fibrosis effect, which was possibly through regulation of TGFβ1/Smad2/Smad3 signalling pathway in endometrial stromal cells.

Bone Marrow Mesenchymal Stem Cells (BMSC)-Upregulated miR-139 Inhibited the Migration and Invasion of Breast Cancer Cells In Vitro

microRNAs exert a crucial impact on tumor biology. However, the biological effect of miR-139 on breast cancer cells remains unclear yet. Here we intend to clarify the effect and mechanism of miR-139 derived from BMSCs on the biological behavior of gastric cancer cells. Breast cancer cells were divided into BMSC group (mixed culture of BMSC and breast cancer cells 1:1), miR-139 mimics group, si-PXN group and control group followed by analysis of miR-139 level, cell activity by MTT assay and the targeted binding of miR-139 to PXN by luciferase reporter assay. In relative to control, miR-139 level was significantly declined in gastric cancer cells, while PXN level was elevated and associated with the prognosis. miR-139 was up-regulated by BMSCs or miR-139 mimics, thereby regulating EMT process through targeted inhibition of PCN, and ultimately inhibiting the activity of breast cancer cells. In conclusion, BMSC co-culture can inhibit PCN by up-regulating miR-139, thereby regulating EMT process and inhibiting breast cancer progression, implying that miR-139 and PXN could be used as therapeutic targets for metastatic breast cancer.

The miR151 and miR5100 Transfected Bone Marrow Stromal Cells Increase Myoblast Fusion in IGFBP2 Dependent Manner

Background

Bone marrow stromal cells (BMSCs) form a perivascular cell population in the bone marrow. These cells do not present naïve myogenic potential. However, their myogenic identity could be induced experimentally in vitro or in vivo. In vivo, after transplantation into injured muscle, BMSCs rarely fused with myofibers. However, BMSC participation in myofiber reconstruction increased if they were modified by NICD or PAX3 overexpression. Nevertheless, BMSCs paracrine function could play a positive role in skeletal muscle regeneration. Previously, we showed that SDF-1 treatment and coculture with myofibers increased BMSC ability to reconstruct myofibers. We also noticed that SDF-1 treatment changed selected miRNAs expression, including miR151 and miR5100.

Methods

Mouse BMSCs were transfected with miR151 and miR5100 mimics and their proliferation, myogenic differentiation, and fusion with myoblasts were analyzed.

Results

We showed that miR151 and miR5100 played an important role in the regulation of BMSC proliferation and migration. Moreover, the presence of miR151 and miR5100 transfected BMSCs in co-cultures with human myoblasts increased their fusion. This effect was achieved in an IGFBP2 dependent manner.

Conclusions

Mouse BMSCs did not present naïve myogenic potential but secreted proteins could impact myogenic cell differentiation. miR151 and miR5100 transfection changed BMSC migration and IGFBP2 and MMP12 expression in BMSCs. miR151 and miR5100 transfected BMSCs increased myoblast fusion in vitro.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12015-022-10350-y.

Potential of Bone-Marrow-Derived Mesenchymal Stem Cells for Maxillofacial and Periodontal Regeneration: A Narrative Review

Bone-marrow-derived mesenchymal stem cells (BM-MSCs) are one of the most widely studied postnatal stem cell populations and are considered to utilize more frequently in cell-based therapy and cancer. These types of stem cells can undergo multilineage differentiation including blood cells, cardiac cells, and osteogenic cells differentiation, thus providing an alternative source of mesenchymal stem cells (MSCs) for tissue engineering and personalized medicine. Despite the ability to reprogram human adult somatic cells to induced pluripotent stem cells (iPSCs) in culture which provided a great opportunity and opened the new door for establishing the in vitro disease modeling and generating an unlimited source for cell base therapy, using MSCs for regeneration purposes still have a great chance to cure diseases. In this review, we discuss the important issues in MSCs biology including the origin and functions of MSCs and their application for craniofacial and periodontal tissue regeneration, discuss the potential and clinical applications of this type of stem cells in differentiation to maxillofacial bone and cartilage in vitro, and address important future hopes and challenges in this field.