Targeting miR-29 mitigates skeletal senescence and bolsters therapeutic potential of mesenchymal stromal cells.

Mesenchymal stromal cell (MSC) senescence is a key factor in skeletal aging, affecting the potential of MSC applications. Identifying targets to prevent MSC and skeletal senescence is crucial. Here, we report increased miR-29 expression in bone tissues of aged mice, osteoporotic patients, and senescent MSCs. Genetic overexpression of miR-29 in Prx1-positive MSCs significantly accelerates skeletal senescence, reducing cortical bone thickness and trabecular bone mass, while increasing femur cross-sectional area, bone marrow adiposity, p53, and senescence-associated secretory phenotype (SASP) levels. Mechanistically, miR-29 promotes senescence by upregulating p53 via targeting Kindlin-2 mRNA. miR-29 knockdown in BMSCs impedes skeletal senescence, enhances bone mass, and accelerates calvarial defect regeneration, also reducing lipopolysaccharide (LPS)-induced organ injuries and mortality. Thus, our findings underscore miR-29 as a promising therapeutic target for senescence-related skeletal diseases and acute inflammation-induced organ damage.

Mesenchymal Stem Cells from Mouse Hair Follicles Inhibit the Development of Type 1 Diabetes.

Mesenchymal stem cells (MSCs) are known for their immunosuppressive properties. Based on the demonstrated anti-inflammatory effect of mouse MSCs from hair follicles (moMSCORS) in a murine wound closure model, this study evaluates their potential for preventing type 1 diabetes (T1D) in C57BL/6 mice. T1D was induced in C57BL/6 mice by repeated low doses of streptozotocin. moMSCORS were injected intravenously on weekly basis. moMSCORS reduced T1D incidence, the insulitis stage, and preserved insulin production in treated animals. moMSCORS primarily exerted immunomodulatory effects by inhibiting CD4+ T cell proliferation and activation. Ex vivo analysis indicated that moMSCORS modified the cellular immune profile within pancreatic lymph nodes and pancreatic infiltrates by reducing the numbers of M1 pro-inflammatory macrophages and T helper 17 cells and upscaling the immunosuppressive T regulatory cells. The proportion of pathogenic insulin-specific CD4+ T cells was down-scaled in the lymph nodes, likely via soluble factors. The moMSCORS detected in the pancreatic infiltrates of treated mice presumably exerted the observed suppressive effect on CD4+ through direct contact. moMSCORS alleviated T1D symptoms in the mouse, qualifying as a candidate for therapeutic products by multiple advantages: non-invasive sampling by epilation, easy access, permanent availability, scalability, and benefits of auto-transplantation.

Optimal Therapeutic Strategy of Bone Marrow-Originated Autologous Mesenchymal Stromal/Stem Cells for ALS.

Amyotrophic lateral sclerosis (ALS) is characterized by selective and progressive neurodegenerative changes in motor neural networks. Given the system complexity, including anatomically distributed sites of degeneration from the motor cortex to the spinal cord and chronic pro-inflammatory conditions, a cell-based therapeutic strategy could be an alternative approach to treating ALS. Lessons from previous mesenchymal stromal/stem cell (MSC) trials in ALS realized the importance of 3 aspects in current and future MSC therapy, including the preparation of MSCs, administration routes and methods, and recipient-related factors. This review briefly describes the current status and future prerequisites for an optimal strategy using bone-marrow-originated MSCs to treat ALS. We suggest mandatory factors in the optimized therapeutic strategy focused on advanced therapy medicinal products produced according to Good Manufacturing Practice, an optimal administration method, the selection of proper patients, and the importance of biomarkers.

Controlled-Release Hydrogel Microspheres to Deliver Multipotent Stem Cells for Treatment of Knee Osteoarthritis.

Osteoarthritis (OA) is the most common form of joint disease affecting articular cartilage and peri-articular tissues. Traditional treatments are insufficient, as they are aimed at mitigating symptoms. Multipotent Stromal Cell (MSC) therapy has been proposed as a treatment capable of both preventing cartilage destruction and treating symptoms. While many studies have investigated MSCs for treating OA, therapeutic success is often inconsistent due to low MSC viability and retention in the joint. To address this, biomaterial-assisted delivery is of interest, particularly hydrogel microspheres, which can be easily injected into the joint. Microspheres composed of hyaluronic acid (HA) were created as MSC delivery vehicles. Microrheology measurements indicated that the microspheres had structural integrity alongside sufficient permeability. Additionally, encapsulated MSC viability was found to be above 70% over one week in culture. Gene expression analysis of MSC-identifying markers showed no change in CD29 levels, increased expression of CD44, and decreased expression of CD90 after one week of encapsulation. Analysis of chondrogenic markers showed increased expressions of aggrecan (ACAN) and SRY-box transcription factor 9 (SOX9), and decreased expression of osteogenic markers, runt-related transcription factor 2 (RUNX2), and alkaline phosphatase (ALPL). In vivo analysis revealed that HA microspheres remained in the joint for up to 6 weeks. Rats that had undergone destabilization of the medial meniscus and had overt OA were treated with empty HA microspheres, MSC-laden microspheres, MSCs alone, or a control vehicle. Pain measurements taken before and after the treatment illustrated temporarily decreased pain in groups treated with encapsulated cells. Finally, the histopathological scoring of each group illustrated significantly less OA damage in those treated with encapsulated cells compared to controls. Overall, these studies demonstrate the potential of using HA-based hydrogel microspheres to enhance the therapeutic efficacy of MSCs in treating OA.

Transient Fever: the Sole Treatment-Related Adverse Event associated with Mesenchymal Stromal Cells and Solid Clues from the Real World.

BACKGROUND: The number of trials investigating mesenchymal stromal cells (MSCs) soars within 3 years which urges a study analysing emerging MSC treatment-related adverse events. AIM: To assess the safety of MSC therapy and provide solid evidence for clinical translation of MSC. METHODS: A meta-analysis of randomized clinical trials (RCTs) published up to April 20th, 2023 was performed. Odds ratio (OR) and 95% confidential intervals (CIs) were used to display pooled results. RESULTS: 152 randomized clinical trials (RCTs) that incorporated 9228 individuals treated with MSCs from autologous or allogenic adipose tissue, bone marrow, Wharton's Jelly, and placenta tissue were included in the analysis. We discovered appropriate 21 MSC treatment-related adverse events (TRAEs), of which fever [OR, 1.61, 95% CI: 1.22-2.11, p<0.01] was the sole event that was closely associated with MSC therapy. MSCs also trended to lower the incidence rate of tachycardia [OR, 0.83, 95% CI: 0.64-1.09, p=0.14] and fatigue [OR, 0.18, 95% CI: 0.61-1.07, p=0.18]. A separate analysis of studies with long-term follow-up (more than 1 year) demonstrated the close relationship between MSCs and fever [OR, 1.75, 95% CI: 1.26-2.24, p<0.01]. The rest TRAEs did not associate themselves with MSC therapy. Dose-response was also conducted for fever, linearity was discovered between MSCs from allogeneic tissue and Wharton's Jelly and fever. CONCLUSION: To date, our results suggest that fever is the only AE closely associated with MSCs.

A new perspective on mesenchymal stem cell-based therapy for liver diseases: restoring mitochondrial function.

Mesenchymal stem cells (MSCs) have emerged as a promising alternative treatment for liver disease due to their roles in regeneration, fibrosis inhibition, and immunoregulation. Mitochondria are crucial in maintaining hepatocyte integrity and function. Mitochondrial dysfunction, such as impaired synthesis of adenosine triphosphate (ATP), decreased activity of respiratory chain complexes, and altered mitochondrial dynamics, is observed in most liver diseases. Accumulating evidence has substantiated that the therapeutic potential of MSCs is mediated not only through their cell replacement and paracrine effects but also through their regulation of mitochondrial dysfunction in liver disease. Here, we comprehensively review the involvement of mitochondrial dysfunction in the development of liver disease and how MSCs can target mitochondrial dysfunction. We also discuss recent advances in a novel method that modifies MSCs to enhance their functions in liver disease. A full understanding of MSC restoration of mitochondrial function and the underlying mechanisms will provide innovative strategies for clinical applications. Video Abstract.

Aged mesenchymal stem cells and inflammation: from pathology to potential therapeutic strategies.

Natural ageing of organisms and corresponding age-related diseases result mainly from stem cell ageing and "inflammaging". Mesenchymal stem cells (MSCs) exhibit very high immune-regulating capacity and are promising candidates for immune-related disease treatment. However, the effect of MSC application is not satisfactory for some patients, especially in elderly individuals. With ageing, MSCs undergo many changes, including altered cell population reduction and differentiation ability, reduced migratory and homing capacity and, most important, defective immunosuppression. It is necessary to explore the relationship between the "inflammaging" and aged MSCs to prevent age-related diseases and increase the therapeutic effects of MSCs. In this review, we discuss changes in naturally ageing MSCs mainly from an inflammation perspective and propose some ideas for rejuvenating aged MSCs in future treatments.

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

BACKGROUND: Ischemic 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. METHODS: Adult 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. RESULTS: The 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. CONCLUSIONS: Treatment with MSC restored the sensory and motor function of cerebral ischemia rats, indicating it may be an effective therapy for ischemic stroke.

Placental mesenchymal stem cells restore glucose and energy homeostasis in obesogenic adipocytes.

Obesity (Ob) depicts a state of energy imbalance(s) being characterized by the accumulation of excessive fat and which predisposes to several metabolic diseases. Mesenchymal stem cells (MSCs) represent a promising option for addressing obesity and its associated metabolic co-morbidities. The present study aims at assessing the beneficial effects of human placental MSCs (P-MSCs) in mitigating Ob-associated insulin resistance (IR) and mitochondrial dysfunction both in vivo and in vitro. Under obesogenic milieu, adipocytes showed a significant reduction in glucose uptake, and impaired insulin signaling with decreased expression of UCP1 and PGC1α, suggestive of dysregulated non-shivering thermogenesis vis-a-vis mitochondrial biogenesis respectively. Furthermore, obesogenic adipocytes demonstrated impaired mitochondrial respiration and energy homeostasis evidenced by reduced oxygen consumption rate (OCR) and blunted ATP/NAD+/NADP+ production respectively. Interestingly, co-culturing adipocytes with P-MSCs activated PI3K-Akt signaling, improved glucose uptake, diminished ROS production, enhanced mitochondrial OCR, improved ATP/NAD+/NADP+ production, and promoted beiging of adipocytes evidenced by upregulated expression of PRDM16, UCP1, and PGC1α expression. In vivo, P-MSCs administration increased the peripheral blood glucose uptake and clearance, and improved insulin sensitivity and lipid profile with a coordinated increase in the ratio of ATP/ADP and NAD+ and NADP+ in the white adipose tissue (WAT), exemplified in WNIN/GR-Ob obese mutant rats. In line with in vitro findings, there was a significant reduction in adipocyte hypertrophy, increased mitochondrial staining, and thermogenesis. Our findings advocate for a therapeutic application of P-MSCs for improving glucose and energy homeostasis, i.e., probably restoring non-shivering thermogenesis towards obesity management.

Temporal extracellular vesicle protein changes following intraarticular treatment with integrin α10ß1-selected mesenchymal stem cells in equine osteoarthritis.

Introduction: Equine osteoarthritis (OA) is a heterogeneous, degenerative disease of the musculoskeletal system with multifactorial causation, characterized by a joint metabolic imbalance. Extracellular vesicles are nanoparticles involved in intracellular communication. Mesenchymal stem cell (MSC) therapy is a form of regenerative medicine that utilizes their properties to repair damaged tissues. Despite its wide use in veterinary practice, the exact mechanism of action of MSCs is not fully understood. The aim of this study was to determine the synovial fluid extracellular vesicle protein cargo following integrin α10ß1-selected mesenchymal stem cell (integrin α10-MSC) treatment in an experimental model of equine osteoarthritis with longitudinal sampling. Methods: Adipose tissue derived, integrin α10-MSCs were injected intraarticularly in six horses 18 days after experimental induction of OA. Synovial fluid samples were collected at day 0, 18, 21, 28, 35, and 70. Synovial fluid was processed and extracellular vesicles were isolated and characterized. Extracellular vesicle cargo was then analyzed using data independent acquisition mass spectrometry proteomics. Results: A total of 442 proteins were identified across all samples, with 48 proteins differentially expressed (FDR ≤ 0.05) between sham-operated control joint without MSC treatment and OA joint treated with MSCs. The most significant pathways following functional enrichment analysis of the differentially abundant protein dataset were serine endopeptidase activity (p = 0.023), complement activation (classical pathway) (p = 0.023), and collagen containing extracellular matrix (p = 0.034). Due to the lack of an OA group without MSC treatment, findings cannot be directly correlated to only MSCs. Discussion: To date this is the first study to quantify the global extracellular vesicle proteome in synovial fluid following MSC treatment of osteoarthritis. Changes in the proteome of the synovial fluid-derived EVs following MSC injection suggest EVs may play a role in mediating the effect of cell therapy through altered joint homeostasis. This is an important step toward understanding the potential therapeutic mechanisms of MSC therapy, ultimately enabling the improvement of therapeutic efficacy.

Therapeutic potential of mesenchymal stem cells for refractory inflammatory and immune skin diseases.

Inflammatory and immunological skin diseases such as psoriasis, systemic sclerosis, dermatomyositis and atopic dermatitis, whose abnormal skin manifestations not only affected life quality but also caused social discrimination, have been wildly concerned. Complex variables such as hereditary predisposition, racial differences, age and gender can influence the prevalence and therapeutic options. The population of patients with unsatisfactory curative effects under current therapies is growing, it's advisable to seek novel and advanced therapies that are less likely to cause systemic damage. Mesenchymal stem cells (MSCs) have been proven with therapeutic benefits in tissue regeneration, self-renewal and differentiation abilities when treating refractory skin disorders in preclinical and clinical studies. Here we highlighted the immune modulation and inflammation suppression of MSCs in skin diseases, summarized current studies, research progress and related clinical trials, hoping to strengthen the confidence of promising MSCs therapy in future clinical application.

COVID-19 immunotherapy: Treatment based on the immune cell-mediated approaches.

Multiple efforts are currently underway to control and treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19) worldwide. Despite all efforts, the virus that emerged in Wuhan city has rapidly spread globally and led to a public health emergency of international concern (PHEIC) due to the lack of approved antiviral therapy. Nevertheless, SARS-CoV-2 has had a significant influence on the evolution of cellular therapeutic approaches. Adoptive immune cell therapy is innovative and offers either promising prophylactic or therapy for patients with moderate-to-severe COVID-19. This approach is aimed at developing safety and providing secure and effective therapy in combination with standard therapy for all COVID-19 infected individuals. Based on the effective results of previous studies on both inflammatory and autoimmune diseases, various immune cell therapies against COVID-19 have been reviewed and discussed. It must be considered that the application of cell therapy for treatment and to eliminate infected respiratory cells could result in excessive inflammation, so this treatment must be used in combination with other treatments, despite its many beneficial efforts.

Iron Oxide Nanoparticles in Mesenchymal Stem Cell Detection and Therapy.

Mesenchymal stem cells (MSCs) exhibit regenerative and reparative properties. However, most MSC-related studies remain to be translated for regular clinical usage, partly due to challenges in pre-transplantation cell labelling and post-transplantation cell tracking. Amidst this, there are growing concerns over the toxicity of commonly used gadolinium-based contrast agents that mediate in-vivo cell detection via MRI. This urges to search for equally effective but less toxic alternatives that would facilitate and enhance MSC detection post-administration and provide therapeutic benefits in-vivo. MSCs labelled with iron oxide nanoparticles (IONPs) have shown promising results in-vitro and in-vivo. Thus, it would be useful to revisit these studies before inventing new labelling approaches. Aiming to inform regenerative medicine and augment clinical applications of IONP-labelled MSCs, this review collates and critically evaluates the utility of IONPs in enhancing MSC detection and therapeutics. It explains the rationale, principle, and advantages of labelling MSCs with IONPs, and describes IONP-induced intracellular alterations and consequent cellular manifestations. By exemplifying clinical pathologies, it examines contextual in-vitro, animal, and clinical studies that used IONP-labelled bone marrow-, umbilical cord-, adipose tissue- and dental pulp-derived MSCs. It compiles and discusses studies involving MSC-labelling of IONPs in combinations with carbohydrates (Venofer, ferumoxytol, dextran, glucosamine), non-carbohydrate polymers [poly(L-lysine), poly(lactide-co-glycolide), poly(L-lactide), polydopamine], elements (ruthenium, selenium, gold, zinc), compounds/stains (silica, polyethylene glycol, fluorophore, rhodamine B, DAPI, Prussian blue), DNA, Fibroblast growth Factor-2 and the drug doxorubicin. Furthermore, IONP-labelling of MSC exosomes is reviewed. Also, limitations of IONP-labelling are addressed and methods of tackling those challenges are suggested.

The safety of MSC therapy over the past 15 years: a meta-analysis.

BACKGROUND: Despite increasing clinical investigations emphasizing the safety of mesenchymal stem cell (MSC) therapy in different populations with different diseases, no article has recently reviewed the adverse events in all populations. AIM: To evaluate the safety of MSC therapy in all populations receiving MSC therapy and explore the potential heterogeneities influencing the clinical application of MSCs. METHODS: The PubMed, Embase, Web of Science and Scopus databases were searched from onset until 1 March 2021. RESULTS: All adverse events are displayed as odds ratios (ORs) and 95% CIs (confidential intervals). In total, 62 randomized clinical trials were included that enrolled 3546 participants diagnosed with various diseases (approximately 20 types of diseases) treated with intravenous or local implantation versus placebo or no treatment. All studies were of high quality, and neither serious publication bias nor serious adverse events (such as death and infection) were discovered across the included studies. The pooled analysis demonstrated that MSC administration was closely associated with transient fever (OR, 3.65, 95% CI 2.05-6.49, p < 0.01), administration site adverse events (OR, 1.98, 95% CI 1.01-3.87, p = 0.05), constipation (OR, 2.45, 95% CI 1.01-5.97, p = 0.05), fatigue (OR, 2.99, 95% CI 1.06-8.44, p = 0.04) and sleeplessness (OR, 5.90, 95% CI 1.04-33.47, p = 0.05). Interestingly, MSC administration trended towards lowering rather than boosting the incidence rate of arrhythmia (OR, 0.62, 95% CI 0.36-1.07, p = 0.09). CONCLUSIONS: Conclusively, MSC administration was safe in different populations compared with other placebo modalities.

Mesenchymal Stem Cell Therapy for Oral Inflammatory Diseases: Research Progress and Future Perspectives.

Mesenchymal stem cell (MSC) therapy for clinical diseases associated with inflammation and tissue damage has become a progressive treatment strategy. MSCs have unique biological functions, such as homing, immune regulation, and differentiation capabilities, which provide the prerequisites for the treatment of clinical diseases. Oral diseases are often associated with abnormal immune regulation and epithelial tissue damage. In this review, we summarize previous studies that use MSC therapy to treat various oral inflammatory diseases, including oral ulceration, allergic diseases, chemo/radiotherapy-induced oral mucositis, periodontitis, osteonecrosis of the jaw, Sjögren's syndrome (SS), among other similar diseases. We highlight MSC treatment as a promising approach in the management of oral inflammatory diseases, and discuss the obstacles that remain and must be overcome for MSC treatment to thrive in the future.

Can mesenchymal stem cell therapy be the interim management of COVID-19?

COVID-19 pandemic has accounted for ~ 4.3 million confirmed cases and ~ 292,000 deaths (till 12th May, 2020) across the globe since its outbreak. Several anti-viral drugs such as RNA dependent RNA polymerase inhibitors (remdesivir, favipiravir, ribavirin), protease inhibitors (lopinavir, ritonavir) and drugs targeting endocytic pathway (hydroxychloroquine) are being evaluated for COVID-19 but standard therapeutics yet not available. Severe health deterioration in critically ill patients is characterized by pulmonary edema, severe respiratory distress, cytokine storm and septic shock. To combat cytokine storm, immune-therapy targeting IL-1, IL-2, IL-6 and TNFα are being evaluated and one of the promising immune-modulator is the mesenchymal stem cells (MSCs) that can surmount the severity of COVID-19 infections. Recent studies have shown that MSC-therapy significantly dampens the cytokine storm in critically ill COVID-19 patients. This communication endows with the insight of stem cell therapy and summarizes the recent studies on COVID-19 patients.

TGF-ß1-Licensed Murine MSCs Show Superior Therapeutic Efficacy in Modulating Corneal Allograft Immune Rejection In Vivo.

Mesenchymal stromal cells (MSCs) are a promising therapeutic option for multiple immune diseases/disorders; however, efficacy of MSC treatments can vary significantly. We present a novel licensing strategy to improve the immunosuppressive capacity of MSCs. Licensing murine MSCs with transforming growth factor-ß1 (TGF-ß MSCs) significantly improved their ability to modulate both the phenotype and secretome of inflammatory bone marrow-derived macrophages and significantly increased the numbers of regulatory T lymphocytes following co-culture assays. These TGF-ß MSC-expanded regulatory T lymphocytes also expressed significantly higher levels of PD-L1 and CD73, indicating enhanced suppressive potential. Detailed analysis of T lymphocyte co-cultures revealed modulation of secreted factors, most notably elevated prostaglandin E2 (PGE2). Furthermore, TGF-ß MSCs could significantly prolong rejection-free survival (69.2% acceptance rate compared to 21.4% for unlicensed MSC-treated recipients) in a murine corneal allograft model. Mechanistic studies revealed that (1) therapeutic efficacy of TGF-ß MSCs is Smad2/3-dependent, (2) the enhanced immunosuppressive capacity of TGF-ß MSCs is contact-dependent, and (3) enhanced secretion of PGE2 (via prostaglandin EP4 [E-type prostanoid 4] receptor) by TGF-ß MSCs is the predominant mediator of Treg expansion and T cell activation and is associated with corneal allograft survival. Collectively, we provide compelling evidence for the use of TGF-ß1 licensing as an unconventional strategy for enhancing MSC immunosuppressive capacity.

Integrin α10ß1-Selected Mesenchymal Stem Cells Mitigate the Progression of Osteoarthritis in an Equine Talar Impact Model.

BACKGROUND: Early intervention with mesenchymal stem cells (MSCs) after articular trauma has the potential to limit progression of focal lesions and prevent ongoing cartilage degeneration by modulating the joint environment and/or contributing to repair. Integrin α10ß1 is the main collagen type II binding receptor on chondrocytes, and MSCs that are selected for high expression of the α10 subunit have improved chondrogenic potential. The ability of α10ß1-selected (integrin α10high) MSCs to protect cartilage after injury has not been investigated. PURPOSE: To investigate integrin α10high MSCs to prevent posttraumatic osteoarthritis in an equine model of impact-induced talar injury. STUDY DESIGN: Controlled laboratory study. METHODS: Focal cartilage injuries were created on the tali of horses (2-5 years, n = 8) by using an impacting device equipped to measure impact stress. Joints were treated with 20 × 106 allogenic adipose-derived α10high MSCs or saline vehicle (control) 4 days after injury. Synovial fluid was collected serially and analyzed for protein content, cell counts, markers of inflammation (prostaglandin E2, tumor necrosis factor α) and collagen homeostasis (procollagen II C-propeptide, collagen type II cleavage product), and glycosaminoglycan content. Second-look arthroscopy was performed at 6 weeks, and horses were euthanized at 6 months. Joints were imaged with radiographs and quantitative 3-T magnetic resonance imaging. Postmortem examinations were performed, and India ink was applied to the talar articular surface to identify areas of cartilage fibrillation. Synovial membrane and osteochondral histology was performed, and immunohistochemistry was used to assess type I and II collagen and lubricin. A mixed effect model with Tukey post hoc and linear contrasts or paired t tests were used, as appropriate. RESULTS: Integrin α10high MSC-treated joints had less subchondral bone sclerosis on radiographs (P = .04) and histology (P = .006) and less cartilage fibrillation (P = .04) as compared with control joints. On gross pathology, less India ink adhered to impact sites in treated joints than in controls, which may be explained by the finding of more prominent lubricin immunostaining in treated joints. Prostaglandin E2 concentration in synovial fluid and mononuclear cell synovial infiltrate were increased in treated joints, suggesting possible immunomodulation by integrin α10high MSCs. CONCLUSION: Intra-articular administration of integrin α10high MSCs is safe, and evidence suggests that the cells mitigate the effects of joint trauma. CLINICAL RELEVANCE: This preclinical study indicates that intra-articular therapy with integrin α10high MSCs after joint trauma may be protective against posttraumatic osteoarthritis.

Neuroprotection by mesenchymal stem cell (MSC) administration is enhanced by local cooling infusion (LCI) in ischemia.

OBJECTIVE: The present study aimed to determine if hypothermia augments the neuroprotection conferred by MSC administration by providing a conducive micro-environment. METHODS: Sprague-Dawley rats were subjected to 1.5 h middle cerebral artery occlusion (MCAO) followed by 6 or 24 h of reperfusion for molecular analyses, as well as 1, 14 and 28 days for brain infarction or functional outcomes. Rats were treated with either MSC (1 × 105), LCI (cold saline, 0.6 ml/min, 5 min) or both. Brain damage was determined by Infarct volume and neurological deficits. Long-term functional outcomes were evaluated using foot-fault and Rota-rod testing. Human neural SHSY5Y cells were investigated in vitro using 2 h oxygen-glucose deprivation (OGD) followed by MSC with or without hypothermia (HT) (34 °C, 4 h). Mitochondrial transfer was assessed by confocal microscope, and cell damage was determined by cell viability, ATP, and ROS level. Protein levels of IL-1ß, BAX, Bcl-2, VEGF and Miro1 were measured by Western blot following 6 h and 24 h of reperfusion and reoxygenation. RESULTS: MSC, LCI, and LCI + MSC significantly reduced infarct volume and deficit scores. Combination therapy of LCI + MSC precipitated better long-term functional outcomes than monotherapy. Upregulation of Miro1 in the combination group increased mitochondrial transfer and lead to a greater increase in neuronal cell viability and ATP, as well as a decrease in ROS. Further, combination therapy significantly decreased expression of IL-1ß and BAX while increasing Bcl-2 and VEGF expression. CONCLUSION: Therapeutic hypothermia upregulated Miro1 and enhanced MSC mitochondrial transfer-mediated neuroprotection in ischemic stroke. Combination of LCI with MSC therapy may facilitate clinical translation of this approach.

Applicability of adipose-derived mesenchymal stem cells in treatment of patients with type 2 diabetes.

Type 2 diabetes mellitus (T2DM) is mainly characterized by insulin resistance (IR) and impaired insulin secretion. The chronic inflammatory process contributed to IR and could also hamper pancreatic ß cell function. However, currently applied treatment cannot reverse ß cell damage or alleviate inflammation. Mesenchymal stem cells (MSCs), the cell-based therapy for their self-renewable, differentiation potential, and immunosuppressive properties, have been demonstrated in displaying therapeutic effects in T2DM. Adipose-derived MSCs (AD-MSCs) attracted more attention due to less harvested inconvenience and ethical issues commonly accompany with bone marrow-derived MSCs (BM-MSCs) and fetal annex-derived MSCs. Both AD-MSC therapy studies and mechanism explorations in T2DM animals presented that AD-MSCs could translate to clinical application. However, hyperglycemia, hyperinsulinemia, and metabolic disturbance in T2DM are crucial for impairment of AD-MSC function, which may limit the therapeutical effects of MSCs. This review focuses on the outcomes and the molecular mechanisms of MSC therapies in T2DM which light up the hope of AD-MSCs as an innovative strategy to cure T2DM.