The effect of autologous bone marrow stromal cells differentiated on scaffolds for canine tibial bone reconstruction

Exosomes from 3D culture of marrow stem cells enhances endothelial cell proliferation, migration, and angiogenesis via activation of the HMGB1/AKT pathway

BACKGROUND

Angiogenesis is an essential step in tissue engineering. MSC exosomes play an important role in angiogenesis. Functional biomolecules in exosomes vested by the culture microenvironment can be transferred to recipient cells and affects their effect. 3D culture can improve the proliferation and activity of MSCs. However, whether exosomes derived from 3D culture of MSCs have an enhanced effect on angiogenesis is unclear.

METHODS

Herein, we compared the bioactivity of exosomes produced by conventional 2D culture (2D-exos) and 3D culture (3D-exos) of bone marrow stem cells (BMSCs) in angiogenesis.

RESULTS

A series of in vitro and in vivo experiments indicated that 3D-exos exhibited stronger effects on HUVEC cell proliferation, migration, tube formation, and in vivo angiogenesis compared with 2D-exos. Moreover, the superiority of 3D-exos might be attributed to the activation of HMGB1/AKT signaling.

CONCLUSIONS

These results indicate that exosomes from 3D culture of MSCs may serve as a potential therapeutic approach for pro-angiogenesis.

Calcitonin gene‑related peptide regulates FOSL2 expression and cell proliferation of BMSCs via mmu_circRNA_003795

Circular RNAs (circRNAs) are a class of non-coding RNAs that may have important regulatory potency in various biological processes. However, the role of circRNAs and their potential functions in bone marrow mesenchymal stem cells of mice (BMSCs) are still ambiguous. The current study aims to examine the expression of circRNAs and to investigate their effects on FOS like 2 AP-1 transcription factor subunit (FOSL2) expression following stimulation of BMSCs with calcitonin gene-related peptide (CGRP). RNA generated from BMSCs stimulated with or without CGRP was used in a microarray to detect expression of circRNAs. There were 58 significantly differentially expressed circRNAs following CGRP treatment, with 44 circRNAs downregulated and 14 upregulated. Bioinformatics analysis and regulatory networks were used to identify the potential interactions between circRNAs and microRNAs (miRs). mmu_circRNA_003795 was significantly increased in the CGRP-stimulated BMSCs compared with the blank control. Silencing of mmu_circRNA_003795, significantly increased the expression of mmu_miR-504-3p, whereas FOSL2 expression and cell proliferation were decreased. Furthermore, silencing of mmu_mir-504-3p using an miR inhibitor led to increased FOSL2 expression. Additionally, silencing of mmu_circRNA_003795 using small interfering RNA induced marked alterations in the cell cycle of BMSCs. The results demonstrated that mmu_circRNA_003795 can indirectly regulate FOSL2 expression via sponging of miR-504-3p, resulting in alterations in BMSC proliferation.

Evaluation of an artificial vertebral body fabricated by a tantalum-coated porous titanium scaffold for lumbar vertebral defect repair in rabbits

Tantalum (Ta)-coated porous Ti-6A1-4V scaffolds have better bioactivity than Ti-6A1-4V scaffolds; however, their bioperformance as an artificial vertebral body (AVB) is unknown. In the present study, we combined a Ta-coated Ti-6A1-4V scaffold with rabbit bone marrow stromal cells (BMSCs) for tissue-engineered AVB (TEAVB) construction and evaluated the healing and fusion efficacy of this scaffold in lumbar vertebral defects after corpectomy in rabbits. The results showed that BMSCs on the surface of the Ta-coated Ti scaffolds proliferated better than BMSCs on Ti scaffolds. Histomorphometry showed better bone formation when using Ta-coated TEAVBs than that with Ti TEAVBs at both 8 and 12 weeks after implantation. In addition, the vertical and rotational stiffness results showed that, compared with uncoated TEAVBs, Ta-coated TEAVBs enhanced rabbit lumbar vertebral defect repair. Our findings demonstrate that Ta-coated TEAVBs have better healing and fusion efficacy than Ti TEAVBs in rabbit lumbar vertebral defects, which indicates their good prospects for clinical application.

Bone Regeneration Induced by Bone Porcine Block with Bone Marrow Stromal Stem Cells in a Minipig Model of Mandibular "Critical Size" Defect

Introduction. Adding stem cells to biodegradable scaffolds to enhance bone regeneration is a valuable option. Different kinds of stem cells with osteoblastic activity were tested, such as bone marrow stromal stem cells (BMSSCs). Aim. To assess a correct protocol for osteogenic stem cell differentiation, so BMSSCs were seeded on a bone porcine block (BPB). Materials and Methods. Bone marrow from six minipigs was extracted from tibiae and humeri and treated to isolate BMSSCs. After seeding on BPB, critical-size defects were created on each mandible of the minipigs and implanted with BPB and BPB/BMSSCs. After three months, histomorphometric analysis was performed. Results. Histomorphometric analysis provided percentages of the three groups. Tissues present in control defects were 23 ± 2% lamellar bone, 28 ± 1% woven bone, and 56 ± 4% marrow spaces; in BPB defects were 20 ± 5% BPB, 32 ± 2% lamellar bone, 24 ± 1% woven bone, and 28 ± 2% marrow spaces; in BPB/BMSSCs defects were 17 ± 4% BPB/BMSSCs, 42 ± 2% lamellar bone, 12 ± 1% woven bone, and 22 ± 3% marrow spaces. Conclusion. BPB used as a scaffold to induce bone regeneration may benefit from the addition of BDPSCs in the tissue-engineered constructs.