Mesenchymal Stem Cells Treatment Research Articles

Mesenchymal stem cells and connective tissue diseases: From bench to bedside.

The pathogenesis of connective tissue diseases (CTDs), represented by systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), primary Sjögren's syndrome (pSS), and idiopathic inflammatory myopathies (IIM), includes various immune cells involved in both innate and adaptive immunity. The mesenchymal stem cells (MSCs) are unique due to their regulatory effect on immunity. This makes them a promising therapeutic approach for patients with immune-mediated disorders such as CTD. The safety and clinical efficacy of MSC treatment in CTD have been tested in a growing number of preclinical and clinical studies. Administration of MSCs has consistently shown benefits with both symptomatic and histologic improvement in CTD animal models. MSC therapies in severe and drug-resistant CTD patients have shown promise in a number of the pilot studies, cohort studies, and randomized controlled trials in SLE, RA, and SSc, but some problems still need to be resolved in the transition from the bench to the bedside. The relevant studies in pSS and IIM are still in their infancy, but have displayed encouraging outcomes. Considerable efficacy variations have been observed in terms of the route of delivery, time of MSC injection, origin of the MSCs and dosage. Furthermore, the optimization of conventional drugs combined with MSC therapies and the applications of novel cell engineering approaches requires additional research. In this review, we summarize the current evidence about the immunoregulatory mechanism of MSCs, as well as the preclinical and clinical studies of MSC-based therapy for the treatment of CTDs.

Asian Pigeonwing Plants (Clitoria ternatea) Synergized Mesenchymal Stem Cells by Modulating the Inflammatory Response in Rats with Cisplatin-Induced Acute Kidney Injury.

Acute kidney injury is a heterogeneous set of disorders distinguished by a sudden decrease in the glomerular filtration rate, which is evidenced by an increase in the serum creatinine concentration or oliguria and categorized by stage and cause. It is an ever-growing health problem worldwide, with no reliable treatment. In the present study, we evaluated the role of Clitoria ternatea combined with mesenchymal stem cells in treating cisplatin-induced acute kidney injury in rats. Animals were challenged with cisplatin, followed by 400 mg/kg of Asian pigeonwing extract and/or mesenchymal stem cells (106 cells/150 g body weight). Kidney functions and enzymes were recorded, and histopathological sectioning was also performed. The expression profile of IL-1β, IL-6, and caspase-3 was assessed using the quantitative polymerase chain reaction. The obtained data indicated that mesenchymal stem cells combined with the botanical extract modulated the creatinine uric acid and urea levels. Cisplatin increased the level of malondialdehyde and decreased the levels of both superoxide dismutase and glutathione; however, the dual treatment was capable of restoring the normal levels. Furthermore, all treatments modulated the IL-6, IL-1β, and caspase-3 gene expression profiles. The obtained data shed some light on adjuvant therapy using C. ternatea and mesenchymal stem cells in treating acute kidney injury; however, further investigations are required to understand these agents' synergistic mechanisms fully. The total RNA was extracted from the control, the positive control, and all of the therapeutically treated animals. The expression profiles of the IL-6, IL-1β, and caspase-3 genes were evaluated using the real-time polymerase chain reaction. Cisplatin treatment caused a significant upregulation in IL-6. All treatments could mitigate the IL-6-upregulating effect of cisplatin, with the mesenchymal stem cell treatment being the most effective. The same profile was observed in the IL-1β and caspase-3 genes, except that the dual treatment (mesenchymal stem cells and the botanical extract) was the most effective in ameliorating the adverse effect of cisplatin; it downregulated caspase-3 expression better than the positive control.

A comparative study of different doses of bone marrow-derived mesenchymal stem cells improve post-stroke neurological outcomes via intravenous transplantation

BackgroundIschemic stroke treatments are intriguing and somewhat controversial. Recent findings have shown that human mesenchymal stem cells (MSC) may have therapeutic potential in ischemic stroke. Our hypothesis was that MSC therapy would promote sensory and motor recovery. Therefore, we intended to explore the optimal transplantation dose of MSC. MethodsAdult Sprague-Dawley (SD) rats were induced to undergo transient focal cerebral ischemia by occluding the middle cerebral artery. A series of standard neurological/neurobehavioral experiments, including Neurological Severity Score (NSS) assessment, corner turning test, von Frey test, and rotarod were then performed on post stroke rats following treatment with vehicle or different doses of MSC (1 × 106, 2 × 106, and 5 × 106) through tail vein. To figure out the time course of neurological and functional recovery following ischemic stroke, tests were administered at regular intervals (days 1, 3, 7, 14, 21, and 28) after reperfusion. And the cerebral infarction volume was measured and analyzed by multi-slices H&E staining and micro-PET / CT in all of the groups at day 35 after ischemia stroke. Activation of microglia was explored by immunofluorescence at day 35 after ischemia stroke. ResultsThe sensory and motor function was significantly improved by MSC treatment in stroke rats, along with cerebral infarction volume reduction. Besides, different doses of MSC have more or less reflected the therapeutic effect on stroke. The prominent treatment outcome in neurobehavioral recovery and infarction reduction was shown in low dose group with an injection dose of 1 × 106 cells. Nevertheless, the medium and high dose MSC could inhibit the activation of microglia much stronger. ConclusionsTreatment with MSC restored the sensory and motor function of cerebral ischemia rats, indicating it may be an effective therapy for ischemic stroke.

Abstract 107: Systemic Allogeneic Mesenchymal Stem Cell Administration Does Not Attenuate Early Post-resuscitation Brain Injury Or Inflammation In A Porcine Model Of Cardiac Arrest

Introduction: Based on emerging evidence that systemic inflammation exacerbates post-resuscitation organ injury, we recently tested the efficacy of allogeneic mesenchymal stem cell (MSC) administration early after return of spontaneous circulation (ROSC) in a porcine model of cardiac arrest (CA). Initial results indicate that MSCs attenuate post-ROSC cardiac dysfunction, but it is unclear if these protective effects extend to the brain. Accordingly, we aimed to determine if systemic allogeneic MSCs reduce early post-ROSC brain injury and inflammation in swine. Methods: Swine (n=33) were subjected to 10 min CA followed by mechanical CPR with defibrillation and epinephrine (EPI; 0.015 mg/kg iv). Animals that achieved ROSC (n=19) were blindly randomized to intra-arterial saline (n=9) or allogeneic bone marrow-derived MSCs (55±2 x 10 6 ; n=10) 30 min post-ROSC. Blood sampling was performed for 4 hours post-ROSC to quantify serum neurofilament light chain (NFL) levels, after which brain tissue was collected for post-mortem quantification of regional neuronal injury (H&E), activated microglia (IBA-1), and inflammatory gene expression (PCR) vs. healthy control swine (n=8). Results: Animals resuscitated from CA exhibited a significant increase in neuronal injury throughout the brain vs. controls that was not affected by MSC treatment ( A ). Similarly, the post-ROSC rise in serum NFL was not different between saline-treated and MSC-treated animals (2.5±0.6 vs. 2.5±0.8 fold-change vs. baseline; p=0.94). A significant increase in activated microglia ( B ) and inflammatory gene expression ( C ) was observed throughout the brain in both CA groups vs. healthy controls, with particularly prominent changes in the striatum but no notable differences between treatment groups. Conclusions: Despite favorable effects on the heart, systemic allogeneic MSC therapy after ROSC does not significantly affect early markers of brain injury and inflammation in a porcine model of CA.

Safety and Efficacy of Mesenchymal Stem Cells in Burn Therapy: Systematic Review

The experimental research on the use of mesenchymal stem cells (MSCs) for burn therapy has been published several times. However, current clinical procedure remains a challenging discussion. This systematic review assesses the safety and efficacy of administering mesenchymal stem cells (MSCs) to burns and determines the most effective source of MSCs for burn therapy. We reviewed several studies through PubMed, Google Scholar, Science Direct, and DOAJ online databases. PRISMA-P 2020 method was used based on inclusion and exclusion criteria that were re-selected through Joanna Briggs Institute (JBI) Critical Appraisal Tools. Results from 13 articles showed that MSCs are safe for burn therapy with minimal side effects/complications and have the potential to repair tissue and accelerate burn healing through several mechanisms. The treatment of MSCs in burns is influenced by donor characteristics and related to the severity and area of the burn. It can be concluded that the administration of MSCs is safe and effective in burn therapy. Keywords: burns, mesenchymal stem cells, therapeutic safety, therapeutic efficacy, wound healing

Mesenchymal Stem Cells Promote Wound Healing and Effects on Expression of Matrix Metalloproteinases-8 and 9 in the Wound Tissue of Diabetic Rats.

Diabetic foot ulcer (DFU) is a multifactorial complication of diabetes, mainly manifested as infection, ulcer, or destruction of deep tissue, and there is currently no effective treatment. Several preclinical and clinical studies have proved that the transplantation of mesenchymal stem cells (MSCs) improved wound healing. In this study, we evaluated the therapeutic efficacy of human umbilical cord (hUC-MSCs) in DFU rat model. One dose of hUC-MSCs (1 × 106 cells) was subcutaneously injected around wounds in male Sprague-Dawley rats. Wound healing was evaluated macroscopically (wound closure) every 3 days. In addition, we measured growth factors and specific proteins [matrix metalloproteinases (MMPs)-9 and MMP-8] on Day 14 post hUC-MSC transplantation. Results showed significant differences in the wound healing kinetics of lesions that received hUC-MSCs compared to lesions that received vehicle (phosphate buffered saline; P < 0.05). Enzyme-linked immunosorbent assay analyses indicated that MMP-9 protein contents were significantly upregulated in DFU animals, while MMP-8 was downregulated compared to the diabetic rats (P < 0.05). After MSC treatment, the level of MMP-9 and MMP-8 decreased and increased compared to the vehicle group, respectively. These findings suggest that hUC-MSC transplantation can ameliorate the healing process of DFU rats and a potential mechanism through which MSCs enhance DFU wound healing by decreasing MMP-9 expression and increasing MMP-8 expression. This study represents a promising opportunity to gain insight into how MSCs mediate wound healing.

Efficacy and Safety of Mesenchymal Stem Cell Therapy in Patients with Acute Myocardial Infarction: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

The adjuvant treatment of stem cell therapy for acute myocardial infarction (AMI) has been studied in multiple clinical trials, but many questions remain to be addressed, such as efficacy, safety, identification of the optimal cell type, tractable route of delivery, transplant dosage, and transplant timing. The current meta-analysis aimed to explore the issues of mesenchymal stem cells (MSCs) transplantation in patients with AMI based on published randomized controlled trials (RCTs) and guide the design of subsequent clinical trials of MSCs therapy for AMI. The Cochrane Library, PubMed, EMBASE databases were searched for relevant clinical trials from January 1, 2000, to January 23, 2021. Results from RCTs involving MSCs transplantation for the treatment of AMI were identified. According to the Cochrane systematic review method, the literature quality, including studies, was evaluated and valid data was extracted. Rev- Man 5.3 and Stata 15.1 software were used for Meta-analysis. After literature search and detailed evaluation, 9 randomized controlled trials enrolling 460 patients were included in the quantitative analysis. Pooled analyses indicated that MSCs therapy was associated with a significantly greater improvement in overall left ventricular ejection fraction (LVEF), and the effect was maintained for up to 24 months. No significant difference in favor of MSCs treatment in left ventricular (LV) volume and in the risk of rehospitalization as a result of heart failure (HF) was noted, compared with the controls. For transplantation dose, the LVEF of patients accepting a MSCs dose of 107-108 cells was significantly increased by 2.62% (95% CI 1.54 to 3.70; P < 0.00001; I2 =0%), but this increase was insignificant in the subgroup that accepted a MSCs dose of < 107 cells (1.65% in LVEF, 95% CI, 0.03 to 3.27; P =0.05; I2 =75%) or >108 cells (4.65% in LVEF, 95% CI, -4.55 to 13.48; P =0.32; I2 =95%), compared with the controls. For transplantation timing, a significant improvement of LVEF of 3.18% was achieved in the group of patients accepting a MSCs infusion within 2 to 14 days after percutaneous coronary intervention (PCI) (95% CI, 2.89 to 3.47; P <0.00001; I2 = 0). There was no association between MSCs therapy and major adverse events. Results from our systematic review suggest that MSCs therapy for patients with AMI appears to be safe and might induce a significant increase in LVEF with a limited impact on LV volume and rehospitalization caused by HF. The effect was maintained for up to 24 months. MSCs dose of 107-108 cells was more likely to achieve better clinical endpoints than <107 or >108 cells. The optimal time window for cell transplantation might be within 2-14 days after PCI. This meta-analysis was registered with PROSPERO, number CRD 42021241104.

Novel fabrication of bioengineered injectable chitosan hydrogel loaded with conductive nanoparticles to improve therapeutic potential of mesenchymal stem cells in functional recovery after ischemic myocardial infarction

In recent decades, myocardial regeneration through stem cell transplantation and tissue engineering has been viewed as a promising technique for treating myocardial infarction. As a result, the researcher attempts to see whether co-culturing modified mesenchymal stem cells with Au@Ch-SF macro-hydrogel and H9C2 may help with tissue regeneration and cardiac function recovery. The gold nanoparticles (Au) incorporated into the chitosan-silk fibroin hydrogel (Au@Ch-SF) were validated using spectral and microscopic examinations. The most essential elements of hydrogel groups were investigated in detail, including weight loss, mechanical strength, and drug release rate. Initially, the cardioblast cells (H9C2 cells) was incubated with Au@Ch-SF macro-hydrogel, followed by mesenchymal stem cells (2 × 105) were transplanted into the Au@Ch-SF macro-hydrogel+H9C2 culture at the ratio of 2:1. Further, cardiac phenotype development, cytokines expression and tissue regenerative performance of modified mesenchymal stem cells treatment were studied through various in vitro and in vivo analyses. The Au@Ch-SF macro-hydrogel gelation time was much faster than that of Ch and Ch-SF hydrogels, showing that Ch and SF exhibited greater intermolecular interactions. The obtained Au@Ch-SF macro-hydrogel has no toxicity on mesenchymal stem cells (MS) or cardiac myoblast (H9C2) cells, according to the biocompatibility investigation. MS cells co-cultured with Au@Ch-SF macro-hydrogel and H9C2 cells also stimulated cardiomyocyte fiber restoration, which has been confirmed in myocardial infarction rats using -MHC and Cx43 myocardial indicators. We developed a novel method of co-cultured therapy using MS cells, Au@Ch-SF macro-hydrogel, and H9C2 cells which could promote the regenerative activities in myocardial ischemia cells. These study findings show that co-cultured MS therapy might be effective for the treatment of myocardial injury.

Mesenchymal stem cells for subchondral bone marrow lesions: From bench to bedside

Subchondral bone marrow lesions (BMLs) are areas of disease within subchondral bone that appear as T1 hypointense and T2 hyperintense ill-defined areas of bone marrow on magnetic resonance imaging. The most common bone marrow lesions include subchondral lesions related to osteoarthritis, osteochondral defects, and avascular necrosis. Emerging therapies include autologous biologic therapeutics, in particular mesenchymal stem cells (MSCs), to maintain and improve cartilage health; MSCs have become a potential treatment option for BMLs given the unmet need for disease modification. Active areas in the preclinical research of bone marrow lesions include the paracrine function of MSCs in pathways of angiogenesis and inflammation, and the use of bioactive scaffolds to optimize the environment for implanted MSCs by facilitating chondrogenesis and higher bone volumes. A review of the clinical data demonstrates improvements in pain and functional outcomes when patients with knee osteoarthritis were treated with MSCs, suggesting that BM-MSCs can be a safe and effective treatment for patients with painful knee osteoarthritis with or without bone marrow lesions. Preliminary data examining MSCs in osteochondral defects suggest they can be beneficial as a subchondral injection alone, or as a surgical augmentation. In patients with hip avascular necrosis, those with earlier stage disease have improved outcomes when core decompression is augmented with MSCs, whereas patients in later stages post-collapse have equivalent outcomes with or without MSC treatment. While the evidence for the use of MSCs in conditions with associated bone marrow lesions seems promising, there remains a need for continued investigation into this treatment as a viable treatment option.

Impact of Adipose-Derived Stem Cells on Aortic Tensile Strength in an Abdominal Aortic Aneurysm Model

INTRODUCTION: Abdominal aortic aneurysm (AAA) is a highly morbid condition with treatment currently limited to operative interventions. Prior literature has demonstrated the ability of mesenchymal stem cells (MSCs) in attenuating AAA formation. We aim to demonstrate the mechanical and structural characteristics of the aorta with MSC treatment. METHODS: 16 Yorkshire pigs underwent retroperitoneal exposure of the aorta. Peri-adventitial elastase and collagenase was applied to induce AAA formation. The aorta was treated with media-soaked (aneurysm) or MSC-soaked (treatment) GelFoam. Aortic diameter was monitored serially at postoperative (POD) 0, 7, 14, and 21. Histopathologic staining was performed for hematoxylin and eosin. Tensile strength was measured using a tensiometer and calculations were made for Young’s modulus and peak maximum strain. RESULTS: All animals survived the surgery and postoperative course. At POD21, mean aortic diameter increased to 1.483 cm +/- 0.31 for the aneurysm group vs 1.11 cm +/- 0.04 for the treatment animals (p < 0.004). The elastic modulus for the aneurysm group was 15.83 mPa +/- 1.61 compared to 22.13 mPa +/- 2.34 for the treatment groups (p = 0.034) (Fig. 1). There was no difference in the peak stress (p = 0.564). Medial thickness in the aneurysm group was reduced compared to the treatment animals (590.5 υm +/- 19.35 vs 646.10 υm +/- 11.97, p = 0.044). CONCLUSION: This is the first study to demonstrate the mechanical effects of stem-cell therapy on a porcine AAA model. Young’s modulus characterizes the capacity of tissue to withstand stress and was preserved in the MSC-treated animals. This mechanical test can be utilized to develop additional cell and drug-based therapies for AAA.

Mesenchymal stem cells alleviate aging in vitro and in vivo.

Aging is a natural and multi-factorial phenomenon associated with multiple human pathologies. Mesenchymal stem cells (MSCs) hold great promise in clinical fields of medicine including tissue repair, cardiovascular disease, and brain ischemic injury. The purpose of this study was to explore the roles of MSCs in improving the condition of aging cells, repairing aging tissues and organs, and extending the life span of elderly mice. This study was carried out both in vitro and in vivo. We used MSCs to intervene with IMR-90 senescent cells induced by D-galactose and aged C57BL/6 mice. After 48 hours of co-culturing the aged cells with MSCs, the up-regulated expression of inflammatory factor, interleukin 6 (IL6), and the down-regulated expression of several growth factors, such as transforming growth factor (TGFβ1) and growth differentiation factor (GDF11), in D-galactose induced senescent cells were reversed. Moreover, compared with aged cells, the number of mitochondria and the telomere length were increased with MSC treatment. Similarly, in aged mice, the symptoms related to aging were improved after MSC treatment: the mouse hair became shiny and dense, and the symptoms of bladder overactivity were relieved. Hematoxylin and eosin (H&E) and Masson's trichrome staining showed that the histopathological changes in skin, bladder, liver, and lung were apparently improved. Treatment with MSCs effectively improves aging-related phenotypes and plays a beneficial role in improving aging and aging-related diseases.

Rapid production method with increased yield of high-purity extracellular vesicles obtained using extended mitochondrial targeting domain peptide.

Extracellular vesicles (EVs) are nano‐sized membranous structures involved in intercellular communication and various physiological and pathological processes. Here, we present a novel method for rapid (within 15 min), large‐scale production of high‐purity EVs using eMTDΔ4, a peptide derived from Noxa. The treatment of mesenchymal stem cells derived from human Wharton's jelly after trypsinization and subsequent eMTDΔ4 stimulation in a chemically defined sucrose buffer with orbital shaking led to a substantial increase (approximately 30‐fold) in EV production with markedly high purity (approximately 45‐fold). These EVs (TS‐eEVs) showed higher regenerative and immunomodulatory potential than natural EVs obtained from the culture media after 48 h. The calcium chelator BAPTA‐AM and calpain inhibitor ALLM, but not the natural EV biogenesis inhibitor GW4869, blocked the TS‐eEV production induced by eMTDΔ4, indicating that the eMTDΔ4‐mediated regulation of intracellular calcium levels and calpain activity are closely associated with the rapid, mass production of TS‐eEVs. The present study may lead to considerable advances in EV‐based drug development and production of stem cell‐derived EVs for cell therapy.

Clinical Consideration for Mesenchymal Stem Cells in Treatment of COVID-19.

COVID-19, which has strongly affected the 21st century, is caused by severe acute respiratory syndrome (SARS)-CoV-2. The emergence of viral variants has rendered even vaccinated people prone to infection; thus, completely eradicating COVID-19 may be impossible. COVID-19 causes hyperinflammation, leading to organ damage and even death. SARS-CoV-2 infects not only the lungs, causing acute respiratory distress syndrome, but also the extrapulmonary organs. Not all patients with COVID-19 respond adequately to treatments with antiviral and anti-inflammatory drugs. Therefore, new treatments are urgently needed. Mesenchymal stem cells (MSCs) exhibit immunomodulatory activity and are used to safely and effectively treat various immune disorders. Evidence has indicated the efficacy of MSCs against COVID-19. However, the safety and efficacy of MSCs must be probed further. For this reason, we explored key clinical challenges associated with MSC therapy for COVID-19, such as sources, administration routes, cell dosage, treatment timepoint, and virus reactivation. We identified several challenges that must be addressed before MSCs can be clinically applied.

Mesenchymal Stem Cells Treatment Aggravates Tumor Growth Regardless Its Route of Administration: An In vivo Study.

to clarify the effect of MSCs in cancer growth and to detect whether the rout of administration (either locally inside the tumor tissue or systemic )could affect the outcome of treatment or not. Eighteen female mice were involved in the study. All mice were subcutaneously inoculated with Ehrlich tumor cells into the right flank. After three week of tumor growth; the mice were divided randomly in to three groups six mice for each ; group I: untreated Erlish tumor group; group II: Erlish tumor treated by local injection of 1 x106 MSCs/week inside the tumor tissue, group III: Erlish tumor treated by systemic injection of 1 x106 MSCs iv in tail vein/week. Tumor growth was recorded .After 4 weeks of stem cells injection, all rats were sacrificed by cervical dislocation and tumor tissues were collected for histopathological study. inflammatory cytokine TNF was assessed by ELISA, lncRNA MALAT ,NFKB and MMP2 genes expression were assessed by Quantitative RT-PCR. Erlish tumor was developed as a well-defined capsule composed by connective tissue infiltrated by inflammatory and neoplastic cells surrounded the tumors. The tumor growth regarding size and weight of tumor tissue was significantly aggravated after both local and systemic treatment MSCs (p value =0.007, 0.001) respectively. Inflammatory cytokines TNF and NFKB were significantly elevated (p value <0.0001), lncRNA MALAT, MMP2 expressions were significantly induced (p value <0.0001), after MSCs treatment with more significant increase in those treated by local intratumor injection of MSCs compared to those treated by systemic MSCs(p value <0.0001). Ehrlich tumor model is feasible and easily monitored tumor model. Although MSCs have anti-inflammatory effect and the ability to regenerate the damaged tissue; it could aggravate tumor growth as it exploited by cancer cells for behave of tumor cells.

Combination Therapy of Mesenchymal Stem Cell Transplantation and Astrocyte Ablation Improve Remyelination in a Cuprizone-Induced Demyelination Mouse Model.

Astrocytes display an active, dual, and controversial role in multiple sclerosis (MS), a chronic inflammatory demyelination disorder. However, mesenchymal stem cells (MSCs) can affect myelination in demyelinating disorders. This study aimed to investigate the effect of single and combination therapies of astrocyte ablation and MSC transplantation on remyelination in the cuprizone (CPZ) model of MS. C57BL/6 mice were fed 0.2% CPZ diet for 12weeks. Astrocytes were ablated twice by L-a-aminoadipate (L-AAA) at the beginning of weeks 13 and 14 whereas MSCs were injected in the corpus callosum at the beginning of week 13. Motor coordination and balance were assessed through rotarod test whereas myelin content was evaluated by Luxol-fast blue (LFB) staining and transmission electron microscopy (TEM). Glial cells were assessed by immunofluorescence staining while mRNA expression was evaluated by quantitative real-time PCR. Combination treatment of ablation of astrocytes and MSC transplantation (CPZ + MSC + L-AAA) significantly decreased motor coordination deficits better than single treatments (CPZ + MSCs or CPZ + L-AAA), in comparison to CPZ mice. In addition, L-AAA and MSCs treatment significantly enhanced remyelination compared to CPZ group. Moreover, combination therapy caused a significant decrease in the number of GFAP+ and Iba-1+ cells, whereas oligodendrocytes were significantly increased in comparison to CPZ mice. Finally, MSC administration resulted in a significant upregulation of BDNF and NGF mRNA expression levels. Our data indicate that transient ablation of astrocytes along with MSCs treatment improve remyelination through enhancing oligodendrocytes and attenuating gliosis in a chronic demyelinating mouse model of MS.

PPARδ Agonist Promotes Type II Cartilage Formation in a Rabbit Osteochondral Defect Model.

Osteoarthritis (OA) is a chronic degenerative joint disease accompanied by an inflammatory milieu that results in painful joints. The pathogenesis of OA is multifactorial, with genetic predisposition, environmental factors, and traumatic injury resulting in the direct or indirect loss of cartilage. The articular cartilage can also be damaged by direct focal traumatic injury. Articular cartilage provides a smooth, deformable bearing surface with a low coefficient of friction, increased contact area, and reduced contact stress. Articular type II hyaline cartilage lines the synovial joints and, when injured, has a limited ability for repair, except for the most superficial layers via diffusion from the synovial fluid, secondary to no blood supply, a complex structure, and a low metabolic rate. Restoring the articular surface can relieve pain and restore function. Although many strategies have been developed to regenerate type II collagen based on the extent of the lesion, surgical treatments are still evolving. The peroxisome proliferator-activated receptor delta (PPARδ) agonist and collagen treatment of mesenchymal stem cells (MSCs) enhance the chondrogenic capacity in vitro. We present a novel technique for cartilage restoration in a rabbit cartilage osteochondral defect model using a PPARδ agonist (GW0742)-infused 3D collagen scaffold to induce type II cartilage from MSCs.

Mesenchymal Stem Cells and Formyl Peptide Receptor 2 Activity in Hyperoxia-Induced Lung Injury in Newborn Mice.

Formyl peptide receptor (FPR) 2 is known to play a critical role in regulating inflammation, including either the pro-inflammatory or pro-resolving effects. However, its role in neonatal hyperoxia-induced lung injury has not been delineated. In this study, we investigate whether mesenchymal stem cells (MSCs) attenuate hyperoxia-induced neonatal lung injury by regulating FPR2 activity. We observed a significant increase in FPR2 levels in alveolar macrophages (RAW264.7 cells) after H2O2-induced stress, which decreased after MSC treatment. In the H2O2-induction model, increased levels of inflammatory cytokines (IL-1α and TNF-α) were significantly reduced in RAW264.7 cells after treatment with WRW4, an inhibitor of FPR2, or MSCs. Viability of lung epithelial cells and endothelial cells was significantly improved when cultured in the conditioned media of RAW264.7 cells treated with WRW4 or MSCs, compared to when cultured in the conditioned media of control RAW265.7 cells exposed to H2O2. For the in vivo study, wild-type and FPR2 knockout (FPR2−/−) C57/BL6 mouse pups were randomly exposed to 80% oxygen or room air from postnatal day (P) 1 to P14. At P5, 2 × 105 MSCs were transplanted intratracheally. MSCs reduced the elevated FPR2 activity at P7 and improved the decreased FPR2 activity as well as the increased immuno-stained FPR2 activity in alveolar macrophages in hyperoxic lungs at P14. Both FPR2−/− and MSCs similarly attenuated impaired alveolarization and angiogenesis, and increased apoptosis and inflammation of hyperoxic lungs without synergistic effects. Our findings suggest that the protective effects of MSCs in hyperoxic lung injury might be related to indirect modulation of FPR2 activity, at least of alveolar macrophages in neonatal mice.

The Effect of Human Bone Marrow Mesenchymal Stem Cell-Derived Exosomes on Cartilage Repair in Rabbits.

Mesenchymal stem cells (MSCs) have shown chondroprotective effects in cartilage repair. However, side effects caused by MSC treatment limit their application in clinic. As a cell-free therapy, MSC-derived exosomes (EXOs) have attracted much more attention in recent years. In the present study, we prepared EXOs from human bone marrow mesenchymal stem cells (hBMSCs) and examined their therapeutic potentials in cartilage repair. Our results showed that the prepared extracellular vesicles exhibit classical features of EXOs, such as cup-like shape, around 100 nm diameter, positive protein markers (CD81, TSG101, and Flotillin 1), and ability of internalization. In primary chondrocytes, the treatment of hBMSC-EXOs markedly increases cell viability and proliferation in a dose-dependent manner. Moreover, wound healing assay showed that hBMSC-EXOs accelerate cell migration in primary chondrocytes. JC-1 staining revealed that the mitochondrial membrane potential was enhanced by hBMSC-EXOs, indicating cell apoptosis was decreased in the presence of hBMSC-EXOs. In rabbits with articular cartilage defects, local administration with hBMSC-EXOs facilitates cartilage regeneration as evidenced by gross view and hematoxylin-eosin (H&E) and Saf-O/Fast Green staining. In addition, the International Cartilage Repair Society (ICRS) score was increased by the application of hBMSC-EXOs. Overall, our data indicate that the treatment with hBMSC-EXOs is a suitable cell-free therapy for treating cartilage defects, and these benefits are likely due to improved cell proliferation and migration in chondrocytes.

Golden Connection Between Stem Cells and Orthopedic Services

Utilization of stem cells in orthopedics has increased dramatically. Consequently, stem cells were discovered to have many roles. Some researchers have used them for regenerative medicine, while some have discovered them as a natural source of immune modulators. Currently, there are several research teams studying the translational potential of stem cells, while clinicians have begun treating patients with orthopedic problems (1).Over the past fifteen years, orthopedic surgeons have prioritized Mesenchymal Stem Cell (MCSs) treatment. Several animal experiments have had favorable results, and there is rising concern over their use in human trials. In these clinical studies, stem cell operations were intended to promote fracture healing and cure nonunion, regenerate articular cartilage in degenerated joints, repair ligament or tendon injuries, and replace degenerative spinal disks (1,2).In past research, stem cells have been used for bone tissue regeneration. Bone tissue engineering presents an alternative treatment that may produce a micromilieu with osteogenic, osteoinductive, and osteoconductive properties. In recent studies, researchers have devised methods for combining MSCs with three-dimensional biodegradable polymeric scaffolds. In addition, Udehiya et al. found that the use of hydroxyapatite scaffolds in conjunction with Bone Marrow-MSCs (BM-MSC) accelerates and enhances the healing of bone segmental defects in a rabbit model compared to the use of hydroxyapatite scaffolds alone. Muwan Chen and colleagues discovered that human BM-MSC combined with hyaluronic acid and b-Tri calcium phosphate-coated polymeric scaffold stimulated osteogenic differentiation, cellular proliferation, and reorganization of the cellular matrix in vitro (1–3).Since 2010, stem cells have undergone a paradigm shift where previously stem cells can differentiate and heal injured organs. This stem cell misunderstanding has led some practitioners in the United States and around the world to advertise the availability of stem cell treatments, e.g., MSC can heal blindness, make paralyzed people walk, and makes old tissue young again. In further studies, it was found that at the site of disease, MSCs rarely or never differentiated into tissue at that location, but they do secrete bioactive factors such as growth factors and their therapeutic effects can be analyzed as a site-specific clinical outcome parameter (2–4).

Microglia-derived CCL2 has a prime role in neocortex neuroinflammation

BackgroundIn myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), several areas of demyelination are detectable in mouse cerebral cortex, where neuroinflammation events are associated with scarce inflammatory infiltrates and blood–brain barrier (BBB) impairment. In this condition, the administration of mesenchymal stem cells (MSCs) controls neuroinflammation, attenuating astrogliosis and promoting the acquisition of stem cell traits by astrocytes. To contribute to the understanding of the mechanisms involved in the pathogenesis of EAE in gray matter and in the reverting effects of MSC treatment, the neocortex of EAE-affected mice was investigated by analyzing the cellular source(s) of chemokine CCL2, a molecule involved in immune cell recruitment and BBB-microvessel leakage.MethodsThe study was carried out by immunohistochemistry (IHC) and dual RNAscope IHC/in situ hybridization methods, using astrocyte, NG2-glia, macrophage/microglia, and microglia elective markers combined with CCL2.ResultsThe results showed that in EAE-affected mice, hypertrophic microglia are the primary source of CCL2, surround the cortex neurons and the damaged BBB microvessels. In EAE-affected mice treated with MSCs, microgliosis appeared diminished very soon (6 h) after treatment, an observation that was long-lasting (tested after 10 days). This was associated with a reduced CCL2 expression and with apparently preserved/restored BBB features. In conclusion, the hallmark of EAE in the mouse neocortex is a condition of microgliosis characterized by high levels of CCL2 expression.ConclusionsThis finding supports relevant pathogenetic and clinical aspects of the human disease, while the demonstrated early control of neuroinflammation and BBB permeability exerted by treatment with MSCs may have important therapeutic implications.