Cyclic biaxial tensile strain promotes bone marrow-derived mesenchymal stem cells to differentiate into cardiomyocyte-like cells by miRNA-27a

Cyclic tensile strain facilitates proliferation and migration of human aortic smooth muscle cells and reduces their apoptosis via miRNA-187-3p

The cardiovascular is a system that contains extremely complex mechanical factors, in which the circulatory flow of blood has rich mechanical laws. Many studies have revealed that mechanical factors play a very important role in the process of revascularization. Hence, it is essential to investigate the mechanical factors in the process of revascularization in depth. A cyclic tensile strain (CTS) was applied to human aortic smooth muscle cells (HASMCs) at a frequency of 1 Hz and amplitudes of 5%, 10% and 15%, respectively. SmallRNA-seq was used to identify differentially expressed miRNAs (DE-miRNAs) responding to CTS in HASMCs. Starbase database predicted the target genes of DE-miRNAs. Metascape was applied for GO and KEGG pathway enrichment analysis and protein–protein interaction network construction. The proliferation and migration of CTS-treated HASMCs were significantly enhanced, and apoptosis were significantly reduced compared to the control group. SmallRNA-seq results demonstrated that 55, 16 and 16 DE-miRNAs were present in 5%, 10% and 15% CTS-treated HASMCs, respectively. Compared to controls, with miR-26a-2-3p and miR-187-3p being the intersection of these DE-miRNAs. Starbase database identified 189 common target genes for miR-26a-2-3p and miR-187-3p. Common target genes are mainly enriched in the basolateral plasma membrane and endocytosis. Further, in vitro experiments exhibited that CTS upregulated miR-187-3p expression, and miR-187-3p enhanced the proliferation and migration of HASMCs and reduced their apoptosis. It is suggested that miR-187-3p may be an important target for CTS participate in the process of cardiovascular disease.

An overview of mesenchymal stem cells and their potential therapeutic benefits in cancer therapy

There has been increased interest in using stem cells for regenerative medicine and cancer therapy in the past decade. Mesenchymal stem cells (MSCs) are among the most studied stem cells due to their unique characteristics, such as self-renewal and developmental potency to differentiate into numerous cell types. MSC use has fewer ethical challenges compared with other types of stem cells. Although a number of studies have reported the beneficial effects of MSC-based therapies in treating various diseases, their contribution to cancer therapy remains controversial. The behaviour of MSCs is determined by the interaction between intrinsic transcriptional genes and extrinsic environmental factors. Numerous studies continue to emerge, as there is no denying the potential of MSCs to treat a wide variety of human afflictions. Therefore, the present review article provided an overview of MSCs and their differences compared with embryonic stem cells, and described the molecular mechanisms involved in maintaining their stemness. In addition, the article examined the therapeutic application of stem cells in the field of cancer. The present article also discussed the current divergent roles of MSCs in cancer therapy and the future potential in this field.

Recent Advances in Maturation of Pluripotent Stem Cell-Derived Cardiomyocytes Promoted by Mechanical Stretch

Stem cells have significant potential use in tissue regeneration, especially for treating cardiac diseases because of their multi-directional differentiation capability. By mimicking the in vivo physiological environment of native cardiomyocytes during their development and maturation, researchers have been able to induce pluripotent stem cell-derived cardiomyocytes (PSC-CMs) at high purity. However, the phenotype of these PSC-CMs is immature compared with that of adult cardiomyocytes. Various strategies have been explored to improve the maturity of PSC-CMs, such as long-term culturing, mechanical stimuli, chemical stimuli, and combinations of these strategies. Among these strategies, mechanical stretch as a key mechanical stimulus plays an important role in PSC-CM maturation. In this review, the optimal parameters of mechanical stretch, the effects of mechanical stretch on maturation of PSC-CMs, underlying molecular mechanisms as well as existing problems are discussed. Mechanical stretch is a powerful approach to promote the maturation of SC-CMs in terms of morphology, structure, and functionality. Nonetheless, further research efforts are needed to reach a satisfactory standard for clinical applications of PSC-CMs in treating cardiac diseases.

Mesenchymal Stem Cells for Cardiac Regeneration: from Differentiation to Cell Delivery

Mesenchymal stem cells (MSCs) are so far the most widely researched stem cells in clinics and used as an experimental cellular therapy module, particularly in cardiac regeneration and repair. Ever since the discovery of cardiomyogenesis induction in MSCs, a wide variety of differentiation protocols have been extensively used in preclinical models. However, pre differentiated MSC-derived cardiomyocytes have not been used in clinical trials; highlighting discrepancies and limitations in its use as a source of derived cardiomyocytes for transplantation to improve the damaged heart function. Therefore, this review article focuses on the strategies used to derive cardiomyocytes-like cells from MSCs isolated from three widely used tissue sources and their differentiation efficiencies. We have further discussed the role of MSCs in inducing angiogenesis as a cellular precursor to endothelial cells and its secretory aspects including exosomes. We have then discussed the strategies used for delivering cells in the damaged heart and how its retention plays a critical role in the overall outcome of the therapy. We have also conversed about the scope of the local and systemic modes of delivery of MSCs and the application of biomaterials to improve the overall delivery efficacy and function. We have finally discussed the advantages and limitations of cell delivery to the heart and the future scope of MSCs in cardiac regenerative therapy.

Autocrine and Paracrine Effects of Vascular Endothelial Cells Promote Cutaneous Wound Healing

Background

When vascular endothelial cells are subjected to external stimuli, paracrine hormones and cytokines act on adjacent cells. The regulation of the biological behaviour of cells is closely related to the maintenance of organ function and the occurrence and development of disease. However, it is unclear whether vascular endothelial cells affect the biological behaviour of cells involved in wound repair through autocrine and paracrine mechanisms and ultimately play a role in wound healing. We aimed to verify the effect of the autocrine and paracrine functions of vascular endothelial cells on wound healing.

Materials and Methods

ELISA was used to detect platelet-derived growth factor, basic fibroblast growth factor, epidermal growth factor, and vascular endothelial growth factor in human umbilical vascular endothelial cell-conditioned medium (HUVEC-CM). Different concentrations of HUVEC-CM were used to treat different stem cells. CCK-8 and scratch assays were used to detect the proliferation and migration ability of each cell. A full-thickness dorsal skin defect model was established in mice, and skin wound healing was observed after the local injection of HUVEC-CM, endothelial cell medium (ECM), or normal saline. H&E staining and immunofluorescence were used to observe the gross morphology of the wound tissue, the epithelial cell migration distance, and the expression of CD3 and CD31.

Results

HUVEC-CM promotes the proliferation and migration of epidermal stem cells, skin fibroblasts, bone marrow mesenchymal stem cells, and HUVECs themselves. Furthermore, HUVEC-CM can promote angiogenesis in mouse skin wounds and granulation tissue formation and can accelerate wound surface epithelialization and collagen synthesis, thereby promoting wound healing.

Conclusion

Our results clearly suggest that it is practicable and effective to promote wound healing with cytokines secreted by vascular endothelial cells in a mouse model.

Knockdown of miR-1275 protects against cardiomyocytes injury through promoting neuromedin U type 1 receptor

The present study aimed to assess the role of miR-1275 in cardiac ischemia reperfusion injury. H9 human embryonic stem cell (hESC)-derived cardiomyocytes stimulated by oxygen-glucose deprivation/reoxygenation (OGD/R) were used to simulate myocardial injury in vitro. miR-1275 expression levels in cells were measured by RT-qPCR. The release of lactate dehydrogenase (LDH) and creatine kinase (CK) was examined through LDH and CK ELISA kits. Cell apoptosis was detected through flow cytometry. A Fura-2 Calcium Flux Assay Kit and a Fluo-4 assay kit were used to determine the Ca²⁺ concentration. Expression levels of proteins were tested by Western blotting. The binding effect of miR-1275 and neuromedin U type 1 receptor (NMUR1) was detected by dual-luciferase activity assay. The results showed that miR-1275 was upregulated in OGD/R-stimulated cardiomyocytes. Inhibition of miR-1275 suppressed the increased activity of LDH and CK, cell apoptosis, reactive oxygen species (ROS) production, intracellular Ca²⁺ concentration and sarcoplasmic reticulum (SR) Ca²⁺ leak induced by OGD/R treatment in cardiomyocytes. miR-1275 directly targets 3'UTR of NMUR1 and negatively regulates NMUR1 expression. Silence of NMUR1 abolished the protecting effect of the miR-1275 antagomir on myocardial OGD/R injury. Our study indicated that the miR-1275 antagomir protects cardiomyocytes from OGD/R injury through the promotion of NMUR1.

Nanomedicine Approaches for Advanced Diagnosis and Treatment of Atherosclerosis and Related Ischemic Diseases

Cardiovascular diseases (CVDs) remain one of the major causes of mortality worldwide. In response to this and other worldwide health epidemics, nanomedicine has emerged as a rapidly evolving discipline that involves the development of innovative nanomaterials and nanotechnologies and their applications in therapy and diagnosis. Nanomedicine presents unique advantages over conventional medicines due to the superior properties intrinsic to nanoscopic therapies. Once used mainly for cancer therapies, recently, tremendous progress has been made in nanomedicine that has led to an overall improvement in the treatment and diagnosis of CVDs. This review elucidates the pathophysiology and potential targets of atherosclerosis and associated ischemic diseases. It may be fruitful to pursue future work in the nanomedicine-mediated treatment of CVDs based on these targets. A comprehensive overview is then provided featuring the latest preclinical and clinical outcomes in cardiovascular imaging, biomarker detection, tissue engineering, and nanoscale delivery, with specific emphasis on nanoparticles, nanostructured scaffolds, and nanosensors. Finally, the challenges and opportunities regarding the future development and clinical translation of nanomedicine in related fields are discussed. Overall, this review aims to provide a deep and thorough understanding of the design, application, and future development of nanomedicine for atherosclerosis and related ischemic diseases.

Bone marrow mesenchymal stem cells differentiate into intestinal epithelioid cells through the ERK1/2 pathway

BACKGROUND/AIMS

Previous studies have found that the injection of rat bone marrow mesenchymal stem cells (rBMSCs) in a mouse model of acute hepatic failure significantly relieves intestinal damage and endotoxemia. However, the mechanism of this process remains unknown. This study demonstrated the differentiation of rBMSCs into enterocyte-like cells and possible molecular mechanisms for this with the aim of finding a new treatment for intestinal epithelial injury and endotoxemia during liver failure.

MATERIALS AND METHODS

rBMSCs were isolated from rat femurs and tibias. Differentiation was induced by co-culturing rBMSCs with rat intestinal epithelial cells (mIEC-6) using Transwell plates; after three, seven, and ten days of induction, expression of specific differentiation molecules were quantified. To inhibit the activity of the Mitogen-activated protein kinase 1/2 (ERK1/2) signaling pathway, an inhibitor of Mitogen-activated protein kinase kinase 1/2 (MEK1/2) was added to the co-culture medium, and western blot analysis was performed after 36 or 72 h to evaluate the expression of ERK1/2 signaling pathway markers (p-MEK1/2 and p-ERK1/2).

RESULTS

The rBMSCs differentiated into enterocyte-like cells when co-cultured with mIEC-6 cells. Inhibition of ERK1/2 signaling abrogated the activity of MEK1/2, but MEK increased after 72 h, and the epithelioid differentiation of rBMSCs was consistent with the change in MEK expression.

CONCLUSION

rBMSCs differentiate into intestinal epithelium after co-culture with mIEC-6 by regulation of the ERK1/2 signaling pathway. Further research is needed to elucidate the network of mechanisms.

Tissue Engineering and Regenerative Medicine: Achievements, Future, and Sustainability in Asia

Exploring innovative solutions to improve the healthcare of the aging and diseased population continues to be a global challenge. Among a number of strategies toward this goal, tissue engineering and regenerative medicine (TERM) has gradually evolved into a promising approach to meet future needs of patients. TERM has recently received increasing attention in Asia, as evidenced by the markedly increased number of researchers, publications, clinical trials, and translational products. This review aims to give a brief overview of TERM development in Asia over the last decade by highlighting some of the important advances in this field and featuring major achievements of representative research groups. The development of novel biomaterials and enabling technologies, identification of new cell sources, and applications of TERM in various tissues are briefly introduced. Finally, the achievement of TERM in Asia, including important publications, representative discoveries, clinical trials, and examples of commercial products will be introduced. Discussion on current limitations and future directions in this hot topic will also be provided.

The physical microenvironment of hematopoietic stem cells and its emerging roles in engineering applications

Stem cells are considered the fundamental underpinnings of tissue biology. The stem cell microenvironment provides factors and elements that play significant roles in controlling the cell fate direction. The bone marrow is an important environment for functional hematopoietic stem cells in adults. Remarkable progress has been achieved in the area of hematopoietic stem cell fate modulation based on the recognition of biochemical factors provided by bone marrow niches. In this review, we focus on emerging evidence that hematopoietic stem cell fate is altered in response to a variety of microenvironmental physical cues, such as geometric properties, matrix stiffness, and mechanical forces. Based on knowledge of these biophysical cues, recent developments in harnessing hematopoietic stem cell niches ex vivo are also discussed. A comprehensive understanding of cell microenvironments helps provide mechanistic insights into pathophysiological mechanisms and underlies biomaterial-based hematopoietic stem cell engineering.

MiR-495 targeting dvl-2 represses the inflammatory response of ankylosing spondylitis

Ankylosing spondylitis (AS) is a type of rheumatic inflammatory disease. miRNAs participate in the process of regulating inflammatory response and bone differentiation. Herein, we aimed to test the effect of miR-495 on AS. The serum and tissues were obtained from traumatic fracture (health) and AS patients. The human fibroblast-like synovial (HFLS) cells were extracted from AS tissues. The contents of inflammatory factors and dishevelled 2 (DVL-2) were examined using enzyme-linked immunosorbent assay (ELISA). The ossification factors were detected by immunohistochemistry assay. Osteoclast was assessed by tartaric acid acid phosphatase (TRAP) assay. The cell viability and luciferase activity were measured using cell counting kit-8 (CCK-8) and dual-luciferase reporter system. The levels of factors were evaluated using quantitative real-time PCR (qRT-PCR) and western blotting. DVL-2 was a target gene for miR-495, according to the MicroRNA.org website and luciferase activity assay. The expressions of miR-495 and DVL-2 were negative corrected in AS. miR-495 and si-DVL-2 did not affect the cell viability. miR-495 and si-DVL-2 obviously inhibited inflammatory response by down-regulating tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 levels, and facilitated bone differentiation by up-regulating osteoprotegerin (OPG) and receptor activator for nuclear factor-κB ligand (RANKL) levels in HFLS cells. Besides, miR-495 and si-DVL-2 increased the expression of wnt3a, runt-related transcription factor 2 (RUNX-2) and β-catenin and reduced the phosphorylation of β-catenin. Collectively, miR-495 depressed inflammatory response and promoted bone differentiation of HFLS cells, and this was accompanied by mediating wnt/β-catenin/Runx-2 pathway by targeting DVL-2.

Double-network gels with dynamic bonds under multi-cycle deformation

Application of double-network (DN) gels with dynamic bonds as implants for repair of damaged and degenerate cartilage tissue and their use as synthetic non-degradable scaffolds for growth, proliferation and differentiation of stem cells requires understanding of the mechanical behavior of these materials under cyclic deformation. A constitutive model is developed for the viscoelastic and viscoplastic responses of DN gels with covalent and non-covalent junctions under multi-cycle loading. Viscoelasticity is treated as breakage and reformation of temporary junctions driven by thermal fluctuations. Viscoplasticity is thought of as sliding of permanent junctions with respect to their initial positions in the polymer network. Adjustable parameters in the governing equations are found by fitting observations in tensile loading-unloading tests with various maximum strains and multi-cycle tests with monotonically increasing maximum elongation ratios per cycle on two DN gels with physical junctions formed due to hydrogen bonds and ionic complexation. Numerical analysis demonstrates the ability of the model not only to describe observations correctly, but also to predict the mechanical response in multi-cycle tests with sophisticated deformation programs. Quantitative and qualitative effects of metal-coordination bonds on the mechanical behavior of supramolecular gels are revealed by simulation.