Ran Kim

Therapeutic Potential of Differentiated Mesenchymal Stem Cells for Treatment of Osteoarthritis

Osteoarthritis (OA) is a chronic, progressive, and irreversible degenerative joint disease. Conventional OA treatments often result in complications such as pain and limited activity. However, transplantation of mesenchymal stem cells (MSCs) has several beneficial effects such as paracrine effects, anti-inflammatory activity, and immunomodulatory capacity. In addition, MSCs can be differentiated into several cell types, including chondrocytes, osteocytes, endothelia, and adipocytes. Thus, transplantation of MSCs is a suggested therapeutic tool for treatment of OA. However, transplanted naïve MSCs can cause problems such as heterogeneous populations including differentiated MSCs and undifferentiated cells. To overcome this problem, new strategies for inducing differentiation of MSCs are needed. One possibility is the application of microRNA (miRNA) and small molecules, which regulate multiple molecular pathways and cellular processes such as differentiation. Here, we provide insight into possible strategies for cartilage regeneration by transplantation of differentiated MSCs to treat OA patients.

Upregulation of miR-23b enhances the autologous therapeutic potential for degenerative arthritis by targeting PRKACB in synovial fluid-derived mesenchymal stem cells from patients.

The use of synovial fluid-derived mesenchymal stem cells (SFMSCs) obtained from patients with degenerative arthropathy may serve as an alternative therapeutic strategy in osteoarthritis (OA) and rheumatoid arthritis (RA). For treatment of OA and RA patients, autologous transplantation of differentiated MSCs has several beneficial effects for cartilage regeneration including immunomodulatory activity. In this study, we induced chondrogenic differentiation of SFMSCs by inhibiting protein kinase A (PKA) with a small molecule and microRNA (miRNA). Chondrogenic differentiation was confirmed by PCR and immunocytochemistry using probes specific for aggrecan, the major cartilaginous proteoglycan gene. Absorbance of alcian blue stain to detect chondrogenic differentiation was increased in H-89 and/or miRNA-23btransfected cells. Furthermore, expression of matrix metalloproteinase (MMP)-9 and MMP-2 was decreased in treated cells. Therefore, differentiation of SFMSCs into chondrocytes through inhibition of PKA signaling may be a therapeutic option for OA or RA patients.

Enhanced Healing of Rat Calvarial Bone Defects with Hypoxic Conditioned Medium from Mesenchymal Stem Cells through Increased Endogenous Stem Cell Migration via Regulation of ICAM-1 Targeted-microRNA-221

The use of conditioned medium from mesenchymal stem cells may be a feasible approach for regeneration of bone defects through secretion of various components of mesenchymal stem cells such as cytokines, chemokines, and growth factors. Mesenchymal stem cells secrete and accumulate multiple factors in conditioned medium under specific physiological conditions. In this study, we investigated whether the conditioned medium collected under hypoxic condition could effectively influence bone regeneration through enhanced migration and adhesion of endogenous mesenchymal stem cells. Cell migration and adhesion abilities were increased through overexpression of intercellular adhesion molecule-1 in hypoxic conditioned medium treated group. Intercellular adhesion molecule-1 was upregulated by microRNA-221 in mesenchymal stem cells because microRNAs are key regulators of various biological functions via gene expression. To investigate the effects in vivo, evaluation of bone regeneration by computed tomography and histological assays revealed that osteogenesis was enhanced in the hypoxic conditioned medium group relative to the other groups. These results suggest that behavioral changes of endogenous mesenchymal stem cells through microRNA-221 targeted-intercellular adhesion molecule-1 expression under hypoxic conditions may be a potential treatment for patients with bone defects.

FOCUSED LOW-INTENSITY PULSED ULTRASOUND ENHANCES BONE REGENERATION IN RAT CALVARIAL BONE DEFECT THROUGH ENHANCEMENT OF CELL PROLIFERATION

A number of studies have reported the therapeutic potential of low-intensity pulsed ultrasound (LIPUS) for induction of bone repair. This study investigated whether bone regeneration might be enhanced by application of focused LIPUS to selectively stimulate fractured calvarial bone. To accomplish this, bone defects were surgically created in the middle of the skull of rats that were subsequently exposed to focused LIPUS. Bone regeneration was assessed by repeated computed tomography imaging after the operation, as well as histologic analysis with calcein, hematoxylin and eosin and proliferating cell nuclear antigen assay. At 6 wk after surgery, bone formation in the focused LIPUS-treated group improved significantly relative to the control. Interestingly, new bone tissue sprouted from focused LIPUS target points. Histologic analysis after exposure to focused LIPUS revealed that proliferating cells were significantly increased relative to the control. Taken together, these results suggest that focused LIPUS can improve re-ossification through enhancement of cell proliferation in calvarial defect sites.

Exogenous miRNA-146a Enhances the Therapeutic Efficacy of Human Mesenchymal Stem Cells by Increasing Vascular Endothelial Growth Factor Secretion in the Ischemia/Reperfusion-Injured Heart

Adult stem cells have been studied as a promising therapeutic modality for the functional restoration of the damaged heart. In the present study, a strategy for enhancing the angiogenic efficacy of human mesenchymal stem cells (hMSCs) using micro-RNA was examined. We investigated whether micro-RNA-146a (miR-146a) influences the secretion of vascular endothelial growth factor (VEGF) and angiogenesis of MSCs. Our data indicated that miR-146a-transfected hMSCs (hMSCmiR-146a) decreased the expression of neurofibromin 2, an inhibitor of p21-activated kinase-1 (PAK1). miR-146a also increased the expression of Ras-related C3 botulinum toxin substrate 1 and PAK1, which are known to induce VEGF expression, and the formation of vascular branches was increased in hMSCmiR-146a compared to hMSCs treated with VEGF. VEGF and p-Akt were increased in hMSCmiR-146a. Furthermore, injection of hMSCmiR-146a after ischemia/reperfusion (I/R) injury led to a reduction of fibrosis area and increased VEGF expression, confirming the regenerative capacity such as reparative angiogenesis in the infarcted area. Cardiac functions in I/R injury were improved following injection of hMSCmiR-146a compared to the I/R group. Taken together, these data suggest that miR-146 is a novel microRNA that regulates VEGF expression, and its use may be an effective strategy for enhancing the therapeutic efficacy of hMSC transplantation into the I/R-injured heart.

Therapeutic Potential of Stem Cells Strategy for Cardiovascular Diseases.

Despite development of medicine, cardiovascular diseases (CVDs) are still the leading cause of mortality and morbidity worldwide. Over the past 10 years, various stem cells have been utilized in therapeutic strategies for the treatment of CVDs. CVDs are characterized by a broad range of pathological reactions including inflammation, necrosis, hyperplasia, and hypertrophy. However, the causes of CVDs are still unclear. While there is a limit to the currently available target-dependent treatments, the therapeutic potential of stem cells is very attractive for the treatment of CVDs because of their paracrine effects, anti-inflammatory activity, and immunomodulatory capacity. Various studies have recently reported increased therapeutic potential of transplantation of microRNA- (miRNA-) overexpressing stem cells or small-molecule-treated cells. In addition to treatment with drugs or overexpressed miRNA in stem cells, stem cell-derived extracellular vesicles also have therapeutic potential because they can deliver the stem cell-specific RNA and protein into the host cell, thereby improving cell viability. Here, we reported the state of stem cell-based therapy for the treatment of CVDs and the potential for cell-free based therapy.

Therapeutic potential of autologous mesenchymal stem cells derived from synovial fluid in patients with degenerative arthritis

The possibility to isolate synovial fluid-derived mesenchymal stem cells (SFMSCs) from patients with degenerative arthropathy has been an interest since synovial fluid (SF) from osteoarthritis (OA) patients offered a unique stem-cell resource for therapeutic applications. In this study, we successfully isolated, cytogenetically and molecularly characterized, and followed the differentiation potency of human mesenchymal stem cells (MSCs) from SF. The morphology of proliferating SFMSCs showed fibroblast-like morphology, and both the population doubling time (DT) and viability of MSCs from bone marrow, adipose, and SF did not differ. The immunophenotype of SFMSCs was confirmed by the positive expression of CD44, CD73, CD90, CD105, and CD106 by flow cytometry and immunocytochemistry, and the expression of the hematopoietic markers, CD34 and CD45, was not found. In all MSCs from three different origins, we measured the mRNA expression of developmentally important transcript factors such as KLF4, c-Myc, Sox2, and OCT4. SFMSCs from OA patients showed normal chromosomal number, structure, and telomerase activity. SFMSCs showed multipotent capacity, and was differentiated into neurocyte, adipocyte, osteocyte, and chondrocyte in vitro, as demonstrated by specific stains and expression of molecular markers. In addition, SFMSCs also have the capacity to secrete immunomodulating factors (IL-4, IL-10, IL-13, and transforming growth factor-β (TGF-β)) involved in the therapy of rheumatoid arthritis (RA). These results demonstrate that SFMSCs from OA-patients might provide therapeutic options for RA and OA.

Alternative new mesenchymal stem cell source exerts tumor tropism through ALCAM and N-cadherin via regulation of microRNA-192 and -218

Gliomas are the most common type of malignant primary brain tumors. Some treatments of gliomas exist, but they are rarely curative. Mesenchymal stem cells (MSCs) are emerging as potential modes of targeted cancer therapy owing to their capacity for homing toward tumor sites. It has been proposed that MSCs derived from various sources, such as bone marrow, adipose tissue and umbilical cord blood, can be used as cell-based therapy for brain tumors. Here, MSCs obtained from the synovial fluid of osteoarthritis or rheumatoid arthritis patients were investigated as therapeutic candidates. Specifically, we compared migratory and adhesive abilities, as well as expression levels of related genes and microRNA in bone marrow derived-MSCs (BMMSCs), adipose derived-MSCs (ADMSCs), and synovial fluid derived-MSCs (SFMSCs) after treatment with conditioned medium from gliomas. Migration and adhesion of SFMSCs increased through upregulation of the activated lymphocyte cell adhesion molecule (ALCAM) and N-cadherin by microRNA-192 and -218 downregulation, similar to BMMSCs and ADMSCs. Migratory capacities of all types of MSCs were evaluated in vivo, and SFMSCs migrated intensively toward gliomas. These results suggest that SFMSCs have potential for use in cell-based antitumor therapies.

Salvia miltiorrhiza enhances the survival of mesenchymal stem cells under ischemic conditions

To validate the enhanced therapeutic effect of Salvia miltiorrhiza Bunge (SM) for brain ischemic stroke through the anti‐apoptotic and survival ability of mesenchymal stem cells (MSCs).