PDGF Restores the Defective Phenotype of Adipose-Derived Mesenchymal Stromal Cells from Diabetic Patients

Mesenchymal Stem Cells in Cancer Therapy

The mesenchymal stem/stromal cells (MSCs) are multipotent cells that were initially discovered in the bone marrow in the late 1960s but have so far been discovered in almost all tissues of the body. The multipotent property of MSCs enables them to differentiate into various cell types and lineages, such as adipocytes, chondrocytes, and osteocytes. The immunomodulation capacity and tumor-targeting features of MSCs made their use crucial for cell-based therapies in cancer treatment, yet limited advancement could be observed in translational medicine prospects due to the need for more information regarding the controversial roles of MSCs in crosstalk tumors. In this review, we discuss the therapeutic potential of MSCs, the controversial roles played by MSCs in cancer progression, and the anticancer therapeutic strategies that are in association with MSCs. Finally, the clinical trials designed for the direct use of MSCs for cancer therapy or for their use in decreasing the side effects of other cancer therapies are also mentioned in this review to evaluate the current status of MSC-based cancer therapies.

Revisiting the role of MicroRNAs in the pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a prevalent chronic pulmonary fibrosis disease characterized by alveolar epithelial cell damage, fibroblast proliferation and activation, excessive extracellular matrix deposition, and abnormal epithelial-mesenchymal transition (EMT), resulting in tissue remodeling and irreversible structural distortion. The mortality rate of IPF is very high, with a median survival time of 2-3 years after diagnosis. The exact cause of IPF remains unknown, but increasing evidence supports the central role of epigenetic changes, particularly microRNA (miRNA), in IPF. Approximately 10% of miRNAs in IPF lung tissue exhibit differential expression compared to normal lung tissue. Diverse miRNA phenotypes exert either a pro-fibrotic or anti-fibrotic influence on the progression of IPF. In the context of IPF, epigenetic factors such as DNA methylation and long non-coding RNAs (lncRNAs) regulate differentially expressed miRNAs, which in turn modulate various signaling pathways implicated in this process, including transforming growth factor-β1 (TGF-β1)/Smad, mitogen-activated protein kinase (MAPK), and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathways. Therefore, this review presents the epidemiology of IPF, discusses the multifaceted regulatory roles of miRNAs in IPF, and explores the impact of miRNAs on IPF through various pathways, particularly the TGF-β1/Smad pathway and its constituent structures. Consequently, we investigate the potential for targeting miRNAs as a treatment for IPF, thereby contributing to advancements in IPF research.

Role of Mesenchymal Stem/Stromal Cells in Head and Neck Cancer-Regulatory Mechanisms of Tumorigenic and Immune Activity, Chemotherapy Resistance, and Therapeutic Benefits of Stromal Cell-Based Pharmacological Strategies

Head and neck cancer (HNC) entails a heterogenous neoplastic disease that arises from the mucosal epithelium of the upper respiratory system and the gastrointestinal tract. It is characterized by high morbidity and mortality, being the eighth most common cancer worldwide. It is believed that the mesenchymal/stem stromal cells (MSCs) present in the tumour milieu play a key role in the modulation of tumour initiation, development and patient outcomes; they also influence the resistance to cisplatin-based chemotherapy, the gold standard for advanced HNC. MSCs are multipotent, heterogeneous and mobile cells. Although no MSC-specific markers exist, they can be recognized based on several others, such as CD73, CD90 and CD105, while lacking the presence of CD45, CD34, CD14 or CD11b, CD79α, or CD19 and HLA-DR antigens; they share phenotypic similarity with stromal cells and their capacity to differentiate into other cell types. In the tumour niche, MSC populations are characterized by cell quiescence, self-renewal capacity, low reactive oxygen species production and the acquisition of epithelial-to-mesenchymal transition properties. They may play a key role in the process of acquiring drug resistance and thus in treatment failure. The present narrative review examines the links between MSCs and HNC, as well as the different mechanisms involved in the development of resistance to current chemo-radiotherapies in HNC. It also examines the possibilities of pharmacological targeting of stemness-related chemoresistance in HNSCC. It describes promising new strategies to optimize chemoradiotherapy, with the potential to personalize patient treatment approaches, and highlights future therapeutic perspectives in HNC.

The issue of heterogeneity of MSC-based advanced therapy medicinal products-a review

Mesenchymal stromal stem cells (MSCs) possess a remarkable potential for numerous clinical applications due to their unique properties including self-renewal, immunomodulation, paracrine actions and multilineage differentiation. However, the translation of MSC-based Advanced Therapy Medicinal Products (ATMPs) into the clinic has frequently met with inconsistent outcomes. One of the suspected reasons for this issue is the inherent and extensive variability that exists among such ATMPs, which makes the interpretation of their clinical efficacy difficult to assess, as well as to compare the results of various studies. This variability stems from numerous reasons including differences in tissue sources, donor attributes, variances in manufacturing protocols, as well as modes of administration. MSCs can be isolated from various tissues including bone marrow, umbilical cord, adipose tissue and others, each with its unique phenotypic and functional characteristics. While MSCs from different sources do share common features, they also exhibit distinct gene expression profiles and functional properites. Donor-specific factors such as age, sex, body mass index, and underlying health conditions can influence MSC phenotype, morphology, differentiation potential and function. Moreover, variations in preparation of MSC products introduces additional heterogeneity as a result of cell culture media composition, presence or absence of added growth factors, use of different serum supplements and culturing techniques. Once MSC products are formulated, storage protocols play a pivotal role in its efficacy. Factors that affect cell viability include cell concentration, delivery solution and importantly, post-thawing protocols where applicable. Ensuing, differences in administration protocols can critically affect the distribution and functionallity of administered cells. As MSC-based therapies continue to advance through numerous clinical trials, implication of strategies to reduce product heterogeneity is imperative. Central to addressing these challenges is the need for precise prediction of clinical responses, which require well-defined MSC populations and harmonized assessment of their specific functions. By addressing these issues by meaningful approaches, such as, e.g., MSC pooling, the field can overcome barriers to advance towards more consistent and effective MSC-based therapies.

Effects of mesenchymal stem cell on dopaminergic neurons, motor and memory functions in animal models of Parkinson's disease: a systematic review and meta-analysis

ABSTRACT

Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, and although restoring striatal dopamine levels may improve symptoms, no treatment can cure or reverse the disease itself. Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson's disease. Mesenchymal stem cells are considered a promising option due to fewer ethical concerns, a lower risk of immune rejection, and a lower risk of teratogenicity. We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function, memory, and preservation of dopaminergic neurons in a Parkinson's disease animal model. We searched bibliographic databases (PubMed/MEDLINE, Embase, CENTRAL, Scopus, and Web of Science) to identify articles and included only peer-reviewed in vivo interventional animal studies published in any language through June 28, 2023. The study utilized the random-effect model to estimate the 95% confidence intervals (CI) of the standard mean differences (SMD) between the treatment and control groups. We use the systematic review center for laboratory animal experimentation's risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment. A total of 33 studies with data from 840 Parkinson's disease model animals were included in the meta-analysis. Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test. Among the stem cell types, the bone marrow MSCs with neurotrophic factor group showed largest effect size (SMD [95% CI] = -6.21 [-9.50 to -2.93], P = 0.0001, I2 = 0.0 %). The stem cell treatment group had significantly more tyrosine hydroxylase positive dopaminergic neurons in the striatum ([95% CI] = 1.04 [0.59 to 1.49], P = 0.0001, I2 = 65.1 %) and substantia nigra (SMD [95% CI] = 1.38 [0.89 to 1.87], P = 0.0001, I2 = 75.3 %), indicating a protective effect on dopaminergic neurons. Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route (SMD [95% CI] = -2.59 [-3.25 to -1.94], P = 0.0001, I2 = 74.4 %). The memory test showed significant improvement only in the intravenous route (SMD [95% CI] = 4.80 [1.84 to 7.76], P = 0.027, I2 = 79.6 %). Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson's disease. Further research is required to determine the optimal stem cell types, modifications, transplanted cell numbers, and delivery methods for these protocols.

Cu(II)-baicalein enhance paracrine effect and regenerative function of stem cells in patients with diabetes

The development of engineered or modified autologous stem cells is an effective strategy to improve the efficacy of stem cell therapy. In this study, the stemness and functionality of adipose stem cells derived from type 1 diabetic donors (T1DM-ASC) were enhanced by treatment with Cu(II)-baicalein microflowers (Cu-MON). After treatment with Cu-MON, T1DM-ASC showed enhanced expression of the genes involved in the cytokine-cytokine receptor interaction pathway and increased cytokine secretion. Among the top 13 differentially expressed genes between T1DM-ASC and Cu-MON-treated T1DM-ASC (CMTA), some genes were also expressed in HUVEC, Myoblast, Myofibroblast, and Vascular Smooth Muscle cells, inferring the common role of these cell types. In vivo experiments showed that CMTA had the same therapeutic effect as adipose-derived stem cells from non-diabetic donors (ND-ASC) at a 15% cell dose, greatly reducing the treatment cost. Taken together, these findings suggest that Cu-MON promoted angiogenesis by promoting the stemness and functionality of T1DM-ASC and influencing multiple overall repair processes, including paracrine effects.

Efficacy of adipose-derived mesenchymal stem cell therapy in the treatment of chronic micro- and macrovascular complications of diabetes

Diabetes mellitus is a highly prevalent disease characterized by hyperglycaemia that damages the vascular system, leading to micro- (retinopathy, neuropathy, nephropathy) and macrovascular diseases (cardiovascular disease). There are also secondary complications of diabetes (cardiomyopathy, erectile dysfunction or diabetic foot ulcers). Stem cell-based therapies have become a promising tool targeting diabetes symptoms and its chronic complications. Among all stem cells, adipose-derived mesenchymal stem cells (ADMSCs) are of great importance because of their abundance, non-invasive isolation and no ethical limitations. Characteristics that make ADMSCs good candidates for cell-based therapy are their wide immunomodulatory properties and paracrine activities through the secretion of an array of growth factors, chemokines, cytokines, angiogenic factors and anti-apoptotic molecules. Besides, after transplantation, ADMSCs show great ex vivo expansion capacity and differentiation to other cell types, including insulin-producing cells, cardiomyocytes, chondrocytes, hepatocyte-like cells, neurons, endothelial cells, photoreceptor-like cells, or astrocytes. Preclinical studies have shown that ADMSC-based therapy effectively improved visual acuity, ameliorated polyneuropathy and foot ulceration, arrested the development and progression of diabetic kidney disease, or alleviated the diabetes-induced cardiomyocyte hypertrophy. However, despite the positive results obtained in animal models, there are still several challenges that need to be overcome before the results of preclinical studies can be translated into clinical applications. To date, there are several clinical trials or ongoing trials using ADMSCs in the treatment of diabetic complications, most of them in the treatment of diabetic foot ulcers. This narrative review summarizes the most recent outcomes on the usage of ADMSCs in the treatment of long-term complications of diabetes in both animal models and clinical trials.

Directing Cell Delivery to Murine Atherosclerotic Aortic Lesions via Targeting Inflamed Circulatory Interface using Nanocarriers

Stem cell therapy holds significant potential for many inflammatory diseases and regenerative medicine applications. However, delivery of therapeutic cells to specific disease sites after systemic administration without indiscriminate trafficking to other non-target tissues is a major limitation of current cell therapies. Here, we describe a novel nanocarrier-directed targeted cell delivery system that enables cell surface coating with dendrimer nanocarriers containing adhesion moieties to serve as a global positioning system "GPS" to guide circulating cells to targeted lesions and mediate the anchoring of cells at the inflammation site. By exploiting cell surface ligands/receptors selectively and/or molecular moieties that are highly expressed on activated endothelium in pathologic disease states, nanocarrier-coated cells containing the counterpart binding receptors/ligands can be enabled to specifically traffic to and dock at vasculature within target lesions. We demonstrate the efficacy of the I-domain fragment of LFA-1 ( id LFA-1) complexed to modified nanocarriers to facilitate homing of mesenchymal stem cells (MSCs) to inflamed luminal endothelial cells on which ICAM-1 is highly expressed in a murine model of aortic atherosclerosis. Our method can overcome challenges imposed by the high velocity and dynamic circulatory flow of the aorta to successfully deliver MSCs to atherosclerotic regions and allow for docking of the potentially therapeutic and immunomodulating cells. This targeted cell-delivery platform can be tailored for selective systemic delivery of various types of therapeutic cells to different disease areas.

Engineered exosomes derived from stem cells: a new brain-targeted strategy

INTRODUCTION

Using engineered exosomes produced from stem cells is an experimental therapeutic approach for treating brain diseases. According to reports, preclinical research has demonstrated notable neurogenesis and angiogenesis effects using modified stem cell-derived exosomes. These biological nanoparticles have a variety of anti-apoptotic, anti-inflammatory, and antioxidant properties that make them very promising for treating nervous system disorders.

AREAS COVERED

This review examines different ways to enhance the delivery of modified stem cell-derived exosomes, how they infiltrate the blood-brain barrier (BBB), and how they facilitate their access to the brain. We would also like to determine whether these nanoparticles have the most significant transmission rates through BBB when targeting brain lesions.

EXPERT OPINION

Using engineered stem cell-derived exosomes for treating brain disorders has generated considerable attention toward clinical research and application. However, stem cell-derived exosomes lack consistency, and their mechanisms of action are uncertain. Therefore, upcoming research needs to prioritize examining the underlying mechanisms and strategies via which these nanoparticles combat neurological disorders.

Cell Therapy of Vascular and Neuropathic Complications of Diabetes: Can We Avoid Limb Amputation?

Globally, a leg is amputated approximately every 30 seconds, with an estimated 85 percent of these amputations being attributed to complications arising from diabetic foot ulcers (DFU), as stated by the American Diabetes Association. Peripheral arterial disease (PAD) is a risk factor resulting in DFU and can, either independently or in conjunction with diabetes, lead to recurring, slow-healing ulcers and amputations. According to guidelines amputation is the recommended treatment for patients with no-option critical ischemia of the limb (CTLI). In this article we propose cell therapy as an alternative strategy for those patients. We also suggest the optimal time-frame for an effective therapy, such as implanting autologous mononuclear cells (MNCs), autologous and allogeneic mesenchymal stromal cells (MSC) as these treatments induce neuropathy relief, regeneration of the blood vessels and tissues, with accelerated ulcer healing, with no serious side effects, proving that advanced therapy medicinal product (ATMPs) application is safe and effective and, hence, can significantly prevent limb amputation.

Scalable mesenchymal stem cell enrichment from bone marrow aspirate using deterministic lateral displacement (DLD) microfluidic sorting

The growing interest in regenerative medicine has opened new avenues for novel cell therapies using stem cells. Bone marrow aspirate (BMA) is an important source of stromal mesenchymal stem cells (MSCs). Conventional MSC harvesting from BMA relies on archaic centrifugation methods, often leading to poor yield due to osmotic stress, high centrifugation force, convoluted workflow, and long experimental time (∼2-3 hours). To address these issues, we have developed a scalable microfluidic technology based on deterministic lateral displacement (DLD) for MSC isolation. This passive, label-free cell sorting method capitalizes on the morphological differences between MSCs and blood cells (platelets and RBCs) for effective separation using an inverted L-shaped pillar array. To improve throughput, we developed a novel multi-chip DLD system that can process 2.5 mL of raw BMA in 20 ± 5 minutes, achieving a 2-fold increase in MSC recovery compared to centrifugation methods. Taken together, we envision that the developed DLD platform will enable fast and efficient isolation of MSCs from BMA for effective downstream cell therapy in clinical settings.

Neutrophils and the Systemic Inflammatory Response Syndrome (SIRS)

We are not entirely able to understand, assess, and modulate the functioning of the immune system in clinical situations that lead to a systemic inflammatory response. In the search for diagnostic and treatment strategies (which are still far from perfect), it became very important to study the pathogenesis and participation of endogenous inflammation mediators. This study attempts to more precisely establish the role of neutrophils in individual phenomena occurring during an inflammatory and anti-inflammatory reaction, taking into account their cidal, immunoregulatory, and reparative abilities. Pro- and anticoagulatory properties of endothelium in systemic inflammatory response syndrome (SIRS) are emphasised, along with the resulting clinical implications (the application of immunotherapy using mesenchymal stem/stromal cells (MSCs) or IL-6 antagonists in sepsis and COVID-19 treatment, among others). Special attention is paid to reactive oxygen species (ROS), produced by neutrophils activated during "respiratory burst" in the course of SIRS; the protective and pathogenic role of these endogenous mediators is highlighted. Moreover, clinically useful biomarkers of SIRS (neutrophil extracellular traps, cell-free DNA, DAMP, TREMs, NGAL, miRNA, selected cytokines, ROS, and recognised markers of endothelial damage from the group of adhesins by means of immunohistochemical techniques) related to the neutrophils are presented, and their role in the diagnosing and forecasting of sepsis, burn disease, and COVID-19 is emphasised. Finally, examples of immunomodulation of sepsis and antioxidative thermal injury therapy are presented.

A novel therapeutic management for diabetes patients with chronic limb-threatening ischemia: comparison of autologous bone marrow mononuclear cells versus allogenic Wharton jelly-derived mesenchymal stem cells

BACKGROUND

Chronic limb-threatening ischemia (CLTI) represents the final stage of peripheral arterial disease. Approximately one-third of patients with CLTI are not eligible for conventional surgical treatments. Furthermore, patients with advanced stage of CLTI are prone to amputation and death. Thus, an effective therapeutic strategy is urgently needed. In this context, autologous bone marrow mononuclear cell (auto-BM-MNC) and allogeneic mesenchymal stem cells represent a promising therapeutic approach for treating CLTI. In this study, we compared the safety and beneficial therapeutic effect of auto-BM-MNC versus allogeneic Wharton jelly-derived mesenchymal stem cells (allo-WJ-MSCs) in diabetic patients with CLTI.

METHODS

We performed a randomized, prospective, double-blind and controlled pilot study. Twenty-four diabetic patients in the advanced stage of CLTI (4 or 5 in Rutherford's classification) and a transcutaneous oxygen pressure (TcPO2) below 30 mmHg were randomized to receive 15 injections of (i) auto-BM-MNC (7.197 × 106 ± 2.984 × 106 cells/mL) (n = 7), (ii) allo-WJ-MSCs (1.333 × 106 cells/mL) (n = 7) or (iii) placebo solution (1 mL) (n = 10), which were administered into the periadventitial layer of the arterial walls under eco-Doppler guidance. The follow-up visits were at months 1, 3, 6, and 12 to evaluate the following parameters: (i) Rutherford's classification, (ii) TcPO2, (iii) percentage of wound closure, (iv) pain, (v) pain-free walking distance, (vi) revascularization and limb-survival proportion, and (vii) life quality (EQ-5D questionnaire).

RESULTS

No adverse events were reported. Patients with CLTI who received auto-BM-MNC and allo-WJ-MSCs presented an improvement in Rutherford's classification, a significant increase in TcPO2 values‬, a reduction in the lesion size in a shorter time, a decrease in the pain score and an increase in the pain-free walking distance, in comparison with the placebo group. In addition, the participants treated with auto-BM-MNC and allo-WJ-MSCs kept their limbs during the follow-up period, unlike the placebo group, which had a marked increase in amputation.

CONCLUSIONS

Our results showed that patients with CLTI treated with auto-BM-MNC and allo-WJ-MSCs conserved 100% of their limb during 12 months of the follow-up compared to the placebo group, where 60% of participants underwent limb amputation in different times. Furthermore, we observed a faster improvement in the allo-WJ-MSC group, unlike the auto-BM-MNC group. Trial registration This study was retrospectively registered at ClinicalTrials.gov (NCT05631444).

Targeted cell delivery of mesenchymal stem cell therapy for cardiovascular disease applications: a review of preclinical advancements

Cardiovascular diseases (CVD) continue to be the leading cause of morbidity and mortality globally and claim the lives of over 17 million people annually. Current management of CVD includes risk factor modification and preventative strategies including dietary and lifestyle changes, smoking cessation, medical management of hypertension and cholesterol lipid levels, and even surgical revascularization procedures if needed. Although these strategies have shown therapeutic efficacy in reducing major adverse cardiovascular events such as heart attack, stroke, symptoms of chronic limb-threatening ischemia (CLTI), and major limb amputation significant compliance by patients and caregivers is required and off-target effects from systemic medications can still result in organ dysfunction. Stem cell therapy holds major potential for CVD applications but is limited by the low quantities of cells that are able to traffic to and engraft at diseased tissue sites. New preclinical investigations have been undertaken to modify mesenchymal stem cells (MSCs) to achieve targeted cell delivery after systemic administration. Although previous reviews have focused broadly on the modification of MSCs for numerous local or intracoronary administration strategies, here we review recent preclinical advances related to overcoming challenges imposed by the high velocity and dynamic flow of the circulatory system to specifically deliver MSCs to ischemic cardiac and peripheral tissue sites. Many of these technologies can also be applied for the targeted delivery of other types of therapeutic cells for treating various diseases.

Inorganic nanoparticle-integrated mesenchymal stem cells: A potential biological agent for multifaceted applications

Mesenchymal stem cell (MSC)-based therapies are flourishing. MSCs could be used as potential therapeutic agents for regenerative medicine due to their own repair function. Meanwhile, the natural predisposition toward inflammation or injury sites makes them promising carriers for targeted drug delivery. Inorganic nanoparticles (INPs) are greatly favored for their unique properties and potential applications in biomedical fields. Current research has integrated INPs with MSCs to enhance their regenerative or antitumor functions. This model also allows the in vivo fate tracking of MSCs in multiple imaging modalities, as many INPs are also excellent contrast agents. Thus, INP-integrated MSCs would be a multifunctional biologic agent with great potential. In this review, the current roles performed by the integration of INPs with MSCs, including (i) enhancing their repair and regeneration capacity via the improvement of migration, survival, paracrine, or differentiation properties, (ii) empowering tumor-killing ability through agent loaded or hyperthermia, and (iii) conferring traceability are summarized. An introduction of INP-integrated MSCs for simultaneous treatment and tracking is also included. The promising applications of INP-integrated MSCs in future treatments are emphasized and the challenges to their clinical translation are discussed.

Adipose-derived Mesenchymal Stem Cells Therapy as a new Treatment Option for Diabetes Mellitus

The worldwide increase in the prevalence of diabetes mellitus has raised the demand for new therapeutic strategies targeting diabetic symptoms and its chronic complications. Among different treatment options for diabetes, adipose-derived mesenchymal stem cells (ADMSCs) therapy attract the most attention. The therapeutic effects of ADMSCs are based primarily on their paracrine release of immunomodulatory, anti-inflammatory, and trophic factors. Animal models of diabetes as well as human clinical trials have shown that ADMSCs can effectively facilitate endogenous β cell regeneration, preserve residual β cell mass, reduce islet graft rejection, regulate the immune system, and ultimately improve insulin sensitivity or ameliorate insulin resistance in peripheral tissues. Nevertheless, transplantation of mesenchymal stem cells is associated with certain risks; therefore recently much attention has been devoted to ADMSCs derivatives, such as exosomes or conditioned media, as therapeutic agents for the treatment of diabetes. Compared to ADMSCs, cell-free therapy has even better therapeutic potential. This narrative review summarizes recent outcomes and molecular mechanisms of ADMSCs action in the treatment for both type 1 DM and type 2 DM, as well as shows their feasibility, benefits, and current limitations.

JAM-A Overexpression in Human Umbilical Cord-Derived Mesenchymal Stem Cells Accelerated the Angiogenesis of Diabetic Wound By Enhancing Both Paracrine Function and Survival of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) is promising in promoting wound healing mainly due to their paracrine function. Nonetheless, the transplanted MSCs presented poor survival with cell dysfunction and paracrine problem in diabetic environment, thus limiting their therapeutic efficacy and clinical application. JAM-A, an adhesion molecule, has been reported to play multi-functional roles in diverse cells. We therefore investigated the potential effect of JAM-A on MSCs under diabetic environment and explored the underlying mechanism. Indeed, high-glucose condition inhibited MSCs viability and JAM-A expression. However, JAM-A abnormality was rescued by lentivirus transfection and JAM-A overexpression promoted MSCs proliferation, migration and adhesion under hyperglycemia. Moreover, JAM-A overexpression attenuated high-glucose-induced ROS production and MSCs apoptosis. The bio-effects of JAM-A on MSCs under hyperglycemia were confirmed by RNA-seq with enrichment analyses. Moreover, Luminex chip results showed JAM-A overexpression dramatically upregulated PDGF-BB and VEGF in the supernatant of MSCs, which was verified by RT-qPCR and western blotting. The supernatant was further found to facilitate HUVECs proliferation, migration and angiogenesis under hyperglycemia. In vivo experiments revealed JAM-A overexpression significantly enhanced MSCs survival, promoted wound angiogenesis, and thus accelerated diabetic wound closure, partially by enhancing PDGF-BB and VEGF expression. This study firstly demonstrated that JAM-A expression of MSCs was inhibited upon high-glucose stimulation. JAM-A overexpression alleviated high-glucose-induced MSCs dysfunction, enhanced their anti-oxidative capability, protected MSCs from hyperglycemia-induced apoptosis and improved their survival, thus strengthening MSCs paracrine function to promote angiogenesis and significantly accelerating diabetic wound healing, which offers a promising strategy to maximize MSCs-based therapy in diabetic wound.

A sustained-release PDGF-BB nanocomposite hydrogel for DM-associated bone regeneration

Regeneration of bone tissue in the environment of diabetes mellitus (DM) remains one of the clinical challenges, with malfunction of stem cells in a high-glucose microenvironment being the primary obstacle. We designed an injectable sustained-release PDGF-BB nanocomposite hydrogel. PDGF-BB, a star molecule for treating various complications of DM, was used for the first time for DM-associated bone regeneration, and we showed that it restored stem cell proliferation and migration and facilitated osteogenesis inhibition under high glucose stimulation by activating ERK and AKT pathways. To address the requirements for continuous PDGF-BB release in GelMA while also increasing mechanical strength, nanoclay LAPONITE® was added, which may still exhibit pro-osteogenic activity in diabetic environments by releasing bioactive ions (Si⁴⁺, Mg²⁺, and Li⁺). This injectable hydrogel heals calvarial lesions successfully in diabetic rats and has the potential to be used as a direct and effective tool for treating diabetic patients.

Mesenchymal stem cell-based therapy for non-healing wounds due to chronic limb-threatening ischemia: A review of preclinical and clinical studies

Progressive peripheral arterial disease (PAD) can result in chronic limb-threatening ischemia (CLTI) characterized by clinical complications including rest pain, gangrene and tissue loss. These complications can propagate even more precipitously in the setting of common concomitant diseases in patients with CLTI such as diabetes mellitus (DM). CLTI ulcers are cutaneous, non-healing wounds that persist due to the reduced perfusion and dysfunctional neovascularization associated with severe PAD. Existing therapies for CLTI are primarily limited to anatomic revascularization and medical management of contributing factors such as atherosclerosis and glycemic control. However, many patients fail these treatment strategies and are considered "no-option," thereby requiring extremity amputation, particularly if non-healing wounds become infected or fulminant gangrene develops. Given the high economic burden imposed on patients, decreased quality of life, and poor survival of no-option CLTI patients, regenerative therapies aimed at neovascularization to improve wound healing and limb salvage hold significant promise. Cell-based therapy, specifically utilizing mesenchymal stem/stromal cells (MSCs), is one such regenerative strategy to stimulate therapeutic angiogenesis and tissue regeneration. Although previous reviews have focused primarily on revascularization outcomes after MSC treatments of CLTI with less attention given to their effects on wound healing, here we review advances in pre-clinical and clinical studies related to specific effects of MSC-based therapeutics upon ischemic non-healing wounds associated with CLTI.

Generation of mesenchymal stromal cells from urine-derived iPSCs of pediatric brain tumor patients

Human induced pluripotent stem cells (iPSCs) provide a virtually inexhaustible source of starting material for next generation cell therapies, offering new opportunities for regenerative medicine. Among different cell sources for the generation of iPSCs, urine cells are clinically relevant since these cells can be repeatedly obtained by non-invasive methods from patients of any age and health condition. These attributes encourage patients to participate in preclinical and clinical research. In particular, the use of urine-derived iPSC products is a convenient strategy for children with brain tumors, which are medically fragile patients. Here, we investigate the feasibility of using urine samples as a source of somatic cells to generate iPSC lines from pediatric patients with brain tumors (BT-iPSC). Urinary epithelial cells were isolated and reprogrammed using non-integrative Sendai virus vectors harboring the Yamanaka factors KLF4, OCT3/4, SOX2 and C-MYC. After reprogramming, BT-iPSC lines were subject to quality assessment and were compared to iPSCs obtained from urine samples of non-tumor pediatric patients (nonT-iPSC). We demonstrated that iPSCs can be successfully derived from a small volume of urine obtained from pediatric patients. Importantly, we showed that BT-iPSCs are equivalent to nonT-iPSCs in terms of morphology, pluripotency, and differentiation capacity into the three germ layers. In addition, both BT-iPSCs and nonT-iPSCs efficiently differentiated into functional mesenchymal stem/stromal cells (iMSC) with immunomodulatory properties. Therefore, this study provides an attractive approach to non-invasively generate personalized iMSC products intended for the treatment of children with brain tumors.

The PDGF Family Is Associated with Activated Tumor Stroma and Poor Prognosis in Ovarian Cancer

The initiation and progression of cancer depend on the genetic alterations inherent in cancer cells, coupled with the mutual interplay of cancer cells with the surrounding tumor stroma. The platelet-derived growth factor (PDGF) family, as a mesenchymal growth factor, was involved in tumor progression by affecting the surrounding tumor stroma in some cancer types. However, the association of the PDGF family with the ovarian cancer stroma remains elusive. In our study, we first explored the expression pattern of the PDGF family using RNA expression profiles from public databases. We found that the PDGF family was highly expressed in tumor stroma compared with the corresponding epithelial components of ovarian cancer. In particular, PDGF receptors were weakly expressed in ovarian cancer tissues compared with the respective normal tissues; even in tumor mass, PDGF receptors were predominantly expressed by tumor stroma rather than ovarian cancer cells. Importantly, functional enrichment analyses and correlation analyses revealed that the PDGF family was strongly associated with activated stromal scores in ovarian cancer, including higher stromal scores, enriched pathways related to the extracellular matrix (ECM) organization and remodeling, elevated cancer-associated fibroblasts (CAFs) infiltration, and increased tumor-associated macrophages (TAMs) infiltration, especially macrophage M2. Besides, the positive correlations of the PDGF family with CAFs infiltration and macrophage M2 infiltration were observed in other various cancer types. Of note, the PDGF family was also involved in tumor progression-related pathways, such as transforming growth factor β (TGF-β) signaling, epithelial-mesenchymal transition (EMT), angiogenesis, and phosphatidylinositol 3-kinase-Akt (PI3K-Akt) signaling. Higher expressions of PDGF receptors were also observed in ovarian cancer patients with venous or lymphatic invasion. Furthermore, we uncovered the prognostic prediction of the PDGF family in ovarian cancer and constructed a PDGF family-based risk prognosis model with a hazard ratio of 1.932 (95%confidence interval (CI) = 1.27–2.95) and P value < 0.01 (AUC = 0.782, 0.752 for 1 year and 2 years, respectively). Taken together, we demonstrated that ovarian cancers with high PDGF family expression biologically exhibit malignant progression behaviors as well as poor clinical survival, which is attributed to the activated tumor stroma in ovarian cancer.

Role of Mesenchymal Stem/Stromal Cells in Coagulation

Mesenchymal stem/stromal cells (MSCs) are widely used in disease models in order to control several phases in the response to injuries, immune reaction, wound healing, and regeneration. MSCs can act upon both the innate and adaptive immune systems and target a broad number of functions, such as the secretion of cytokines, proteolytic enzymes, angiogenic factors, and the regulating of cell proliferation and survival. The role of MSCs in coagulation has been less studied. This review evaluates the properties and main functions of MSCs in coagulation. MSCs can regulate coagulation in a wide range of pathways. MSCs express and release tissue factors (TF), one of the key regulators of the extrinsic coagulation pathways; MSCs can trigger platelet production and contribute to platelet activation. Altogether, MSCs seem to have a pro-thrombotic role and their superior characterization prior to their administration is necessary in order to prevent adverse coagulation events.

Emerging roles of mesenchymal stem cell therapy in patients with critical limb ischemia

Critical limb ischemia (CLI), the terminal stage of peripheral arterial disease (PAD), is characterized by an extremely high risk of amputation and vascular issues, resulting in severe morbidity and mortality. In patients with severe limb ischemia with no alternative therapy options, such as endovascular angioplasty or bypass surgery, therapeutic angiogenesis utilizing cell-based therapies is vital for increasing blood flow to ischemic regions. Mesenchymal stem cells (MSCs) are currently considered one of the most encouraging cells as a regenerative alternative for the surgical treatment of CLI, including restoring tissue function and repairing ischemic tissue via immunomodulation and angiogenesis. The regenerative treatments for limb ischemia based on MSC therapy are still considered experimental. Despite recent advances in preclinical and clinical research studies, it is not recommended for regular clinical use. In this study, we review the immunomodulatory features of MSC besides the current understanding of different sources of MSC in the angiogenic treatment of CLI subjects and their potential applications as therapeutic agents. Specifically, this paper concentrates on the most current clinical application issues, and several recommendations are provided to improve the efficacy of cell therapy for CLI patients.

Oxidative Stress and Lipid Peroxidation: Prospective Associations Between Ferroptosis and Delayed Wound Healing in Diabetic Ulcers

Diabetic ulcers are one of the major complications of diabetes, and patients usually suffer from amputation and death due to delayed ulcer wound healing. Persistent inflammation and oxidative stress at the wound site are the main manifestations of delayed wound healing in diabetic ulcers. In addition, chronic hyperglycemia in patients can lead to circulatory accumulation of lipid peroxidation products and impaired iron metabolism pathways leading to the presence of multiple free irons in plasma. Ferroptosis, a newly discovered form of cell death, is characterized by intracellular iron overload and accumulation of iron-dependent lipid peroxides. These indicate that ferroptosis is one of the potential mechanisms of delayed wound healing in diabetic ulcers and will hopefully be a novel therapeutic target for delayed wound healing in diabetic patients. This review explored the pathogenesis of diabetic ulcer wound healing, reveals that oxidative stress and lipid peroxidation are common pathological mechanisms of ferroptosis and delayed wound healing in diabetic ulcers. Based on strong evidence, it is speculated that ferroptosis and diabetic ulcers are closely related, and have value of in-depth research. We attempted to clarify prospective associations between ferroptosis and diabetic ulcers in terms of GPX4, iron overload, ferroptosis inhibitors, AGEs, and HO-1, to provide new ideas for exploring the clinical treatment of diabetic ulcers.

Translating MSC Therapy in the Age of Obesity

Mesenchymal stromal cell (MSC) therapy has seen increased attention as a possible option to treat a number of inflammatory conditions including COVID-19 acute respiratory distress syndrome (ARDS). As rates of obesity and metabolic disease continue to rise worldwide, increasing proportions of patients treated with MSC therapy will be living with obesity. The obese environment poses critical challenges for immunomodulatory therapies that should be accounted for during development and testing of MSCs. In this review, we look to cancer immunotherapy as a model for the challenges MSCs may face in obese environments. We then outline current evidence that obesity alters MSC immunomodulatory function, drastically modifies the host immune system, and therefore reshapes interactions between MSCs and immune cells. Finally, we argue that obese environments may alter essential features of allogeneic MSCs and offer potential strategies for licensing of MSCs to enhance their efficacy in the obese microenvironment. Our aim is to combine insights from basic research in MSC biology and clinical trials to inform new strategies to ensure MSC therapy is effective for a broad range of patients.

Heterogeneity of In Vitro Expanded Mesenchymal Stromal Cells and Strategies to Improve Their Therapeutic Actions

Beneficial properties of mesenchymal stromal cells (MSCs) have prompted their use in preclinical and clinical research. Accumulating evidence has been provided for the therapeutic effects of MSCs in several pathologies, including neurodegenerative diseases, myocardial infarction, skin problems, liver disorders and cancer, among others. Although MSCs are found in multiple tissues, the number of MSCs is low, making in vitro expansion a required step before MSC application. However, culture-expanded MSCs exhibit notable differences in terms of cell morphology, physiology and function, which decisively contribute to MSC heterogeneity. The changes induced in MSCs during in vitro expansion may account for the variability in the results obtained in different MSC-based therapy studies, including those using MSCs as living drug delivery systems. This review dissects the different changes that occur in culture-expanded MSCs and how these modifications alter their therapeutic properties after transplantation. Furthermore, we discuss the current strategies developed to improve the beneficial effects of MSCs for successful clinical implementation, as well as potential therapeutic alternatives.

Innovative Cell and Platelet Rich Plasma Therapies for Diabetic Foot Ulcer Treatment: The Allogeneic Approach

Cutaneous chronic wounds are a major global health burden in continuous growth, because of population aging and the higher incidence of chronic diseases, such as diabetes. Different treatments have been proposed: biological, surgical, and physical. However, most of these treatments are palliative and none of them can be considered fully satisfactory. During a spontaneous wound healing, endogenous regeneration mechanisms and resident cell activity are triggered by the released platelet content. Activated stem and progenitor cells are key factors for ulcer healing, and they can be either recruited to the wound site from the tissue itself (resident cells) or from elsewhere. Transplant of skin substitutes, and of stem cells derived from tissues such as bone marrow or adipose tissue, together with platelet-rich plasma (PRP) treatments have been proposed as therapeutic options, and they represent the today most promising tools to promote ulcer healing in diabetes. Although stem cells can directly participate to skin repair, they primarily contribute to the tissue remodeling by releasing biomolecules and microvesicles able to stimulate the endogenous regeneration mechanisms. Stem cells and PRP can be obtained from patients as autologous preparations. However, in the diabetic condition, poor cell number, reduced cell activity or impaired PRP efficacy may limit their use. Administration of allogeneic preparations from healthy and/or younger donors is regarded with increasing interest to overcome such limitation. This review summarizes the results obtained when these innovative treatments were adopted in preclinical animal models of diabetes and in diabetic patients, with a focus on allogeneic preparations.

Mesenchymal Stem Cells Derived from Umbilical Cord Blood having Excellent Stemness Properties with Therapeutic Benefits - a New Era in Cancer Treatment

Mesenchymal stem cells (MSCs) are the most promising candidates for cellular therapies, and most therapeutic applications have focused on MSCs produced from adult bone marrow, despite mounting evidence that MSCs are present in a wide range of conditions. Umbilical cord blood (UCB) is a valuable source of hematopoietic stem cells, but its therapeutic potential extends beyond the hematopoietic component, which also suggests solid organ regenerative potential. With potential ranging from embryonic-like to lineage-committed progenitor cells, many different stems and progenitor cell populations have been postulated. MSC is currently inferred by numerous clinical applications for human UCB. aAs stem cell therapy kicks off some new research and these cells show such a boon to stem cell therapy, it is nevertheless characteristic that the prospect of UCB conservation is gaining momentum. Taken together, the experience described here shows that MSCs derived from UCB are seen as attractive therapeutic candidates for various human disorders including cancer. It is argued that a therapeutic stem cell transplant, using stem cells from UCB, provides a reliable repository of early precursor cells that can be useful in a large number of different conditions, considering issues of safety, availability, transplant methodology, rejection, and side effects. In particular, we focus on the concept of isolation and expansion, comparing the phenotype with MSC derived from the UCB, describing the ability to differentiate, and lastly, the therapeutic potential concerning stromal support, stemness characteristic, immune modulation, and cancer stem cell therapy. Thus it is an overview of the therapeutic application of UCB derived MSCs, with a special emphasis on cancer. Besides, the current evidence on the double-edged sword of MSCs in cancer treatment and the latest advances in UCB-derived MSC in cancer research will be discussed.

E-Selectin-Overexpressing Mesenchymal Stem Cell Therapy Confers Improved Reperfusion, Repair, and Regeneration in a Murine Critical Limb Ischemia Model

AIMS

Novel cell-based therapeutic angiogenic treatments for patients with critical limb ischemia may afford limb salvage. Mesenchymal stem cells (MSCs) do not overexpress E-selectin; however, we have previously demonstrated the cell-adhesion molecule's vital role in angiogenesis and wound healing. Thus, we created a viral vector to overexpress E-selectin on MSCs to increase their therapeutic profile.

METHODS AND RESULTS

Femoral artery ligation induced hind limb ischemia in mice and intramuscular injections were administered of vehicle or syngeneic donor MSCs, transduced ex vivo with an adeno-associated viral vector to express either GFP+ (MSCGFP) or E-selectin-GFP+ (MSCE-selectin-GFP). Laser Doppler Imaging demonstrated significantly restored reperfusion in MSCE-selectin-GFP-treated mice vs. controls. After 3 weeks, the ischemic limbs in mice treated with MSCE-selectin-GFP had increased footpad blood vessel density, hematoxylin and eosin stain (H&E) ischemic calf muscle sections revealed mitigated muscular atrophy with restored muscle fiber size, and mice were able to run further before exhaustion. PCR array-based gene profiling analysis identified nine upregulated pro-angiogenic/pro-repair genes and downregulated Tumor necrosis factor (TNF) gene in MSCE-selectin-GFP-treated limb tissues, indicating that the therapeutic effect is likely achieved via upregulation of pro-angiogenic cytokines and downregulation of inflammation.

CONCLUSION

This innovative cell therapy confers increased limb reperfusion, neovascularization, improved functional recovery, decreased muscle atrophy, and thus offers a potential therapeutic method for future clinical studies.

Klotho and Mesenchymal Stem Cells: A Review on Cell and Gene Therapy for Chronic Kidney Disease and Acute Kidney Disease

Chronic kidney disease (CKD) and acute kidney injury (AKI) are public health problems, and their prevalence rates have increased with the aging of the population. They are associated with the presence of comorbidities, in particular diabetes mellitus and hypertension, resulting in a high financial burden for the health system. Studies have indicated Klotho as a promising therapeutic approach for these conditions. Klotho reduces inflammation, oxidative stress and fibrosis and counter-regulates the renin-angiotensin-aldosterone system. In CKD and AKI, Klotho expression is downregulated from early stages and correlates with disease progression. Therefore, the restoration of its levels, through exogenous or endogenous pathways, has renoprotective effects. An important strategy for administering Klotho is through mesenchymal stem cells (MSCs). In summary, this review comprises in vitro and in vivo studies on the therapeutic potential of Klotho for the treatment of CKD and AKI through the administration of MSCs.

Allogeneic vs. autologous mesenchymal stem/stromal cells in their medication practice

Mesenchymal stem/stromal cell (MSC)-based therapeutics is already available for treatment of a range of diseases or medical conditions. Autologous or allogeneic MSCs obtained from self or donors have their own advantages and disadvantages in their medical practice. Therapeutic benefits of using autologous vs. allogeneic MSCs are inconclusive. Transplanted MSCs within the body interact with their physical microenvironment or niche, physiologically or pathologically, and such cells in a newly established tissue microenvironment may be impacted by the pathological harmful environmental factors to alter their unique biological behaviors. Meanwhile, a temporary microenvironment/niche may be also altered by the resident or niche-surrounding MSCs. Therefore, the functional plasticity and heterogeneity of MSCs caused by different donors and subpopulations of MSCs may result in potential uncertainty in their safe and efficacious medical practice. Acknowledging a connection between MSCs' biology and their existing microenvironment, donor-controlled clinical practice for the long-term therapeutic benefit is suggested to further consider minimizing MSCs potential harm for MSC-based individual therapies. In this review, we summarize the advantages and disadvantages of autologous vs. allogeneic MSCs in their therapeutic applications. Among other issues, we highlight the importance of better understanding of the various microenvironments that may affect the properties of niche-surrounding MSCs and discuss the clinical applications of MSCs within different contexts for treatment of different diseases including cardiomyopathy, lupus and lupus nephritis, diabetes and diabetic complications, bone and cartilage repair, cancer and tissue fibrosis.

Adipose-Derived Stem Cells Secretome and Its Potential Application in "Stem Cell-Free Therapy"

Adipose-derived stem cells (ASCs) secrete many cytokines, proteins, growth factors, and extracellular vesicles with beneficial outcomes that can be used in regenerative medicine. It has great potential, and the development of new treatment strategies using the ASCs secretome is of global interest. Besides cytokines, proteins, and growth factors, the therapeutic effect of secretome is hidden in non-coding RNAs such as miR-21, miR-24, and miR-26 carried via exosomes secreted by adequate cells. The whole secretome, including ASC-derived exosomes (ASC-exos) has been proven in many studies to have immunomodulatory, proangiogenic, neurotrophic, and epithelization activity and can potentially be used for neurodegenerative, cardiovascular, respiratory, inflammatory, and autoimmune diseases as well as wound healing treatment. Due to limitations in the use of stem cells in cell-based therapy, its secretome with emphasis on exosomes seems to be a reasonable and safer alternative with increased effectiveness and fewer side effects. Moreover, the great advantage of cell-free therapy is the possibility of biobanking the ASCs secretome. In this review, we focus on the current state of knowledge on the use of the ASCs secretome in stem cell-free therapy.

Mesenchymal stromal cell-mediated immune regulation: A promising remedy in the therapy of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a major threat to global public health, with increasing prevalence as well as high morbidity and mortality, to which immune dysfunction has been recognized as a crucial contributor. Mesenchymal stromal cells (MSCs), obtained from various sources and possessing potent immunomodulatory abilities, have displayed great therapeutic potential for T2DM. Interestingly, the immunomodulatory capabilities of MSCs are endowed and plastic. Among the multiple mechanisms involved in MSC-mediated immune regulation, the paracrine effects of MSCs have attracted much attention. Of note, extracellular vesicles (EVs), an important component of MSC secretome, have emerged as pivotal mediators of their immunoregulatory effects. Particularly, the necrobiology of MSCs, especially apoptosis, has recently been revealed to affect their immunomodulatory functions in vivo. In specific, a variety of preclinical studies have demonstrated the beneficial effects of MSCs on improving islet function and ameliorating insulin resistance. More importantly, clinical trials have further uncovered the therapeutic potential of MSCs for T2DM. In this review, we outline current knowledge regarding the plasticity and underlying mechanisms of MSC-mediated immune modulation, focusing on the paracrine effects. We also summarize the applications of MSC-based therapies for T2DM in both preclinical studies and clinical trials, with particular emphasis on the modulation of immune system.

Inhibition of miR-199a-5p rejuvenates aged mesenchymal stem cells derived from patients with idiopathic pulmonary fibrosis and improves their therapeutic efficacy in experimental pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is an age-related disease with no cure. Mesenchymal stem cell (MSC)-based therapy has emerged as a novel strategy for IPF treatment. Nevertheless, MSCs derived from patients with IPF (IPF-MSCs) become senescent, thereby reducing their beneficial effects in IPF. MicroRNAs (miRNAs) mediate the senescence of MSCs, but the underlying mechanisms are not fully understood. We investigated the mechanisms by which miR-199a-5p regulates IPF-MSC senescence and whether its inhibition could rejuvenate IPF-MSCs and enhance their therapeutic efficacy.

Methods

Control-MSCs and IPF-MSCs were isolated from the adipose tissue of age-matched healthy and IPF donors, respectively. Cell senescence was examined by senescence-associated β-galactosidase (SA-β-gal) staining. The level of miR-199a-5p was measured by RT-PCR. Autophagy was determined using a transmission electron microscope (TEM). The therapeutic efficacy of anti-miR-199a-5p-IPF-MSCs was assessed using a mouse model of bleomycin-induced lung fibrosis.

Results

Despite similar surface makers, IPF-MSCs exhibited increased cellular senescence and decreased proliferative capacity compared with control-MSCs. The expression of miR-199a-5p was significantly enhanced in the serum of IPF patients and IPF-MSCs compared with that of healthy donors and control-MSCs. The upregulation of miR-199a-5p induced senescence of control-MSCs, whereas the downregulation rescued IPF-MSC senescence. Mechanistically, miR-155-5p suppressed autophagy of MSCs via the AMPK signaling pathway by downregulating the expression of Sirtuin 1(Sirt1), resulting in cellular senescence. Accordingly, miR-155-5p inhibition promoted autophagy and ameliorated IPF-MSC senescence by activating the Sirt1/AMPK signaling pathway. Compared with IPF-MSCs, the transplantation of anti-miR-199a-5p-IPF-MSCs increased the ability to prevent progression of pulmonary fibrosis in bleomycin-treated mice.

Conclusions

Our study shows that miR-199a-5p regulates MSC senescence in patients with IPF by regulating the Sirt1/AMPK signaling pathway and miR-199a-5p is a novel target to rejuvenate IPF-MSCs and enhance their beneficial effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02215-x.

Mesenchymal Stem Cell Therapy for Diabetic Kidney Disease: A Review of the Studies Using Syngeneic, Autologous, Allogeneic, and Xenogeneic Cells

Diabetic kidney disease (DKD) is a microvascular complication of diabetes mellitus (DM) and comprises multifactorial pathophysiologic mechanisms. Despite current treatment, around 30-40% of individuals with type 1 and type 2 DM (DM1 and DM2) have progressive DKD, which is the most common cause of end-stage chronic kidney disease worldwide. Mesenchymal stem cell- (MSC-) based therapy has important biological and therapeutic implications for curtailing DKD progression. As a chronic disease, DM may impair MSC microenvironment, but there is compelling evidence that MSC derived from DM1 individuals maintain their cardinal properties, such as potency, secretion of trophic factors, and modulation of immune cells, so that both autologous and allogeneic MSCs are safe and effective. Conversely, MSCs derived from DM2 individuals are usually dysfunctional, exhibiting higher rates of senescence and apoptosis and a decrease in clonogenicity, proliferation, and angiogenesis potential. Therefore, more studies in humans are needed to reach a conclusion if autologous MSCs from DM2 individuals are effective for treatment of DM-related complications. Importantly, the bench to bedside pathway has been constructed in the last decade for assessing the therapeutic potential of MSCs in the DM setting. Laboratory research set the basis for establishing further translation research including preclinical development and proof of concept in model systems. Phase I clinical trials have evaluated the safety profile of MSC-based therapy in humans, and phase II clinical trials (proof of concept in trial participants) still need to answer important questions for treating DKD, yet metabolic control has already been documented. Therefore, randomized and controlled trials considering the source, optimal cell number, and route of delivery in DM patients are further required to advance MSC-based therapy. Future directions include strategies to reduce MSC heterogeneity, standardized protocols for isolation and expansion of those cells, and the development of well-designed large-scale trials to show significant efficacy during a long follow-up, mainly in individuals with DKD.

Mesenchymal stem cell-derived exosome: a promising alternative in the therapy of Alzheimer's disease

Alzheimer's disease (AD) has been a devastating public health with the development of global aging. Approaches for reducing the current AD epidemic are becoming a primary focus of human healthcare due to the lack of achieved lasting and complete remission strategies to treat AD with the characteristics of heterogeneity and complexity. Exosomes, which is the new emerging approach to intercellular communication, provide novel perspective on identified therapeutic strategies of AD. Mesenchymal stem cell-derived exosomes (MSC-exos) are emerging to be an appealing therapeutic tool for AD, with the donor-derived properties and the characteristics of minimal immunogenicity, effortless storage, nature delivery vehicles, and low risks of tumor formation based on the previous researches. In this review, we elaborate the mechanism of MSC-exos in the treatment of AD and discuss limitations in the clinical application.

Therapeutic Potential of Mesenchymal Stem Cells for Cancer Therapy

Mesenchymal stem cells (MSCs) are among the most frequently used cell type for regenerative medicine. A large number of studies have shown the beneficial effects of MSC-based therapies to treat different pathologies, including neurological disorders, cardiac ischemia, diabetes, and bone and cartilage diseases. However, the therapeutic potential of MSCs in cancer is still controversial. While some studies indicate that MSCs may contribute to cancer pathogenesis, emerging data reported the suppressive effects of MSCs on cancer cells. Because of this reality, a sustained effort to understand when MSCs promote or suppress tumor development is needed before planning a MSC-based therapy for cancer. Herein, we provide an overview on the therapeutic application of MSCs for regenerative medicine and the processes that orchestrates tissue repair, with a special emphasis placed on cancer, including central nervous system tumors. Furthermore, we will discuss the current evidence regarding the double-edged sword of MSCs in oncological treatment and the latest advances in MSC-based anti-cancer agent delivery systems.

Increasing the Therapeutic Potential of Stem Cell Therapies for Critical Limb Ischemia

Peripheral Arterial Disease (PAD) is a progressive, atherosclerotic disease that at its end stage, Critical Limb Ischemia (CLI), results in severely diminished limb perfusion and causes leg pain at rest, non-healing ulcers, and tissue gangrene. Many patients with CLI fail current medical and surgical therapies and thus are deemed "no option" and require limb amputation. Novel therapies to attempt limb salvage in these "no option" patients are needed. Stem cell therapy is one therapeutic angiogenic avenue that has been tested over the last 20 years. To date, clinical trials have shown promise but with only modest improvement and none demonstrated a significant decrease in amputation rates in those treated with stem cell therapy. Thus, recent investigations into improving stem cell therapy have been the focus of our laboratory and many others. This review aims to describe recent advances in increasing the therapeutic potential of stem cell therapies for CLI.

Adipose-Derived Mesenchymal Stem Cells Isolated from Patients with Abdominal Aortic Aneurysm Exhibit Senescence Phenomena

Mesenchymal stem cells (MSCs) have shown beneficial effects in the treatment of abdominal aortic aneurysm (AAA). Nonetheless, the biological properties of adipose-derived MSCs (ASCs) from patients with AAA (AAA-ASCs) remain unclear. This study is aimed at investigating the properties of cell phenotype and function of AAA-ASCs compared with ASCs from age-matched healthy donors (H-ASCs). H-ASCs and AAA-ASCs were studied for cell phenotype, differentiation capacity, senescence, and mitochondrial and autophagic functions. Cellular senescence was examined by senescence-associated β-galactosidase (SA-β-gal) staining. Mitochondrial morphology was determined by MitoTracker staining. Despite the similar surface markers of AAA-ASCs and H-ASCs, AAA-ASCs exhibited altered multidifferentiation potential. Compared with H-ASCs, AAA-ASCs displayed enhanced senescence manifested by increased SA-β-gal activity and decreased proliferation and migration ability. Furthermore, AAA-ASCs showed increased mitochondrial fusion, reactive oxygen species (ROS) production, and decreased mitochondrial membrane potential. In addition, AAA-ASCs exhibited decreased autophagy level, upregulation of IL-6 and TNF-α secretion, and downregulation of IL-10 secretion compared with H-ASCs. Nonetheless, treatment of AAA-ASCs with rapamycin (an autophagy activator) dramatically reduced secretion of IL-6 and TNF-α and enhanced secretion of IL-10. In conclusion, our study showed that AAA-ASCs exhibit senescence phenomena and decreased cell function. Understanding the specific alterations in AAA-ASCs will help explore novel strategies to restore cell function for AAA treatment.

Multi-Parameter Analysis of Biobanked Human Bone Marrow Stromal Cells Shows Little Influence for Donor Age and Mild Comorbidities on Phenotypic and Functional Properties

Heterogeneous populations of human bone marrow-derived stromal cells (BMSC) are among the most frequently tested cellular therapeutics for treating degenerative and immune disorders, which occur predominantly in the aging population. Currently, it is unclear whether advanced donor age and commonly associated comorbidities affect the properties of ex vivo-expanded BMSCs. Thus, we stratified cells from adult and elderly donors from our biobank (n = 10 and n = 13, mean age 38 and 72 years, respectively) and compared their phenotypic and functional performance, using multiple assays typically employed as minimal criteria for defining multipotent mesenchymal stromal cells (MSCs). We found that BMSCs from both cohorts meet the standard criteria for MSC, exhibiting similar morphology, growth kinetics, gene expression profiles, and pro-angiogenic and immunosuppressive potential and the capacity to differentiate toward adipogenic, chondrogenic, and osteogenic lineages. We found no substantial differences between cells from the adult and elderly cohorts. As positive controls, we studied the impact of in vitro aging and inflammatory cytokine stimulation. Both conditions clearly affected the cellular properties, independent of donor age. We conclude that in vitro aging rather than in vivo donor aging influences BMSC characteristics.

Mesenchymal Stromal Cell Therapeutic Delivery: Translational Challenges to Clinical Application

For several decades, multipotent mesenchymal stromal cells (MSCs) have been extensively studied for their therapeutic potential across a wide range of diseases. In the preclinical setting, MSCs demonstrate consistent ability to promote tissue healing, down-regulate excessive inflammation and improve outcomes in animal models. Several proposed mechanisms of action have been posited and demonstrated across an array of in vitro models. However, translation into clinical practice has proven considerably more difficult. A number of prominent well-funded late-phase clinical trials have failed, thus calling out for new efforts to optimize product delivery in the clinical setting. In this review, we discuss novel topics critical to the successful translation of MSCs from pre-clinical to clinical applications. In particular, we focus on the major routes of cell delivery, aspects related to hemocompatibility, and potential safety concerns associated with MSC therapy in the different settings.

Cost-Effective, Safe, and Personalized Cell Therapy for Critical Limb Ischemia in Type 2 Diabetes Mellitus

Cell therapy is a progressively growing field that is rapidly moving from preclinical model development to clinical application. Outcomes obtained from clinical trials reveal the therapeutic potential of stem cell-based therapy to deal with unmet medical treatment needs for several disorders with no therapeutic options. Among adult stem cells, mesenchymal stem cells (MSCs) are the leading cell type used in advanced therapies for the treatment of autoimmune, inflammatory and vascular diseases. To date, the safety and feasibility of autologous MSC-based therapy has been established; however, their indiscriminate use has resulted in mixed outcomes in preclinical and clinical studies. While MSCs derived from diverse tissues share common properties depending on the type of clinical application, they markedly differ within clinical trials in terms of efficacy, resulting in many unanswered questions regarding the application of MSCs. Additionally, our experience in clinical trials related to critical limb ischemia pathology (CLI) shows that the therapeutic efficacy of these cells in different animal models has only been partially reproduced in humans through clinical trials. Therefore, it is crucial to develop new research to identify pitfalls, to optimize procedures and to clarify the repair mechanisms used by these cells, as well as to be able to offer a next generation of stem cell that can be routinely used in a cost-effective and safe manner in stem cell-based therapies targeting CLI.

Human Mesenchymal Stem Cells Prevent Neurological Complications of Radiotherapy

Radiotherapy is a highly effective tool for the treatment of brain cancer. However, radiation also causes detrimental effects in the healthy tissue, leading to neurocognitive sequelae that compromise the quality of life of brain cancer patients. Despite the recognition of this serious complication, no satisfactory solutions exist at present. Here we investigated the effects of intranasal administration of human mesenchymal stem cells (hMSCs) as a neuroprotective strategy for cranial radiation in mice. Our results demonstrated that intranasally delivered hMSCs promote radiation-induced brain injury repair, improving neurological function. This intervention confers protection against inflammation, oxidative stress, and neuronal loss. hMSC administration reduces persistent activation of damage-induced c-AMP response element-binding signaling in irradiated brains. Furthermore, hMSC treatment did not compromise the survival of glioma-bearing mice. Our findings encourage the therapeutic use of hMSCs as a non-invasive approach to prevent neurological complications of radiotherapy, improving the quality of life of brain tumor patients.

Nature vs. Nurture: Defining the Effects of Mesenchymal Stromal Cell Isolation and Culture Conditions on Resiliency to Palmitate Challenge

As MSC products move from early development to clinical translation, culture conditions shift from xeno- to xeno-free systems. However, the impact of isolation and culture-expansion methods on the long-term resiliency of MSCs within challenging transplant environments is not fully understood. Recent work in our lab has shown that palmitate, a saturated fatty acid elevated in the serum of patients with obesity, causes MSCs to convert from an immunosuppressive to an immunostimulatory state at moderate to high physiological levels. This demonstrated that metabolically-diseased environments, like obesity, alter the immunomodulatory efficacy of healthy donor MSCs. In addition, it highlighted the need to test MSC efficacy not only in ideal conditions, but within challenging metabolic environments. To determine how the choice of xeno- vs. xeno-free media during isolation and expansion would affect future immunosuppressive function, umbilical cord explants from seven donors were subdivided and cultured within xeno- (fetal bovine serum, FBS) or xeno-free (human platelet lysate, PLT) medias, creating 14 distinct MSC preparations. After isolation and primary expansion, umbilical cord MSCs (ucMSC) were evaluated according to the ISCT minimal criteria for MSCs. Following baseline characterization, ucMSC were exposed to physiological doses of palmitate and analyzed for metabolic health, apoptotic induction, and immunomodulatory potency in co-cultures with stimulated human peripheral blood mononuclear cells. The paired experimental design (each ucMSC donor grown in two distinct culture environments) allowed us to delineate the contribution of inherent (nature) vs. environmentally-driven (nurture) donor characteristics to the phenotypic response of ucMSC during palmitate exposure. Culturing MSCs in PLT-media led to more consistent growth characteristics during the isolation and expansion for all donors, resulting in faster doubling times and higher cell yields compared to FBS. Upon palmitate challenge, PLT-ucMSCs showed a higher susceptibility to palmitate-induced metabolic disturbance, but less susceptibility to palmitate-induced apoptosis. Most striking however, was that the PLT-ucMSCs resisted the conversion to an immunostimulatory phenotype better than their FBS counterparts. Interestingly, examining MSC suppression of PBMC proliferation at physiologic doses of palmitate magnified the differences between donors, highlighting the utility of evaluating MSC products in stress-based assays that reflect the challenges MSCs may encounter post-transplantation.

Differential adhesion and fibrinolytic activity of mesenchymal stem cells from human bone marrow, placenta, and Wharton's jelly cultured in a fibrin hydrogel

Mesenchymal stem cells isolated from different tissues should share associated markers and the capability to differentiate to mesodermal lineages. However, their behavior varies in specific microenvironments. Herein, adhesion and fibrinolytic activity of mesenchymal stem cells from placenta, bone marrow, and Wharton’s jelly were evaluated in fibrin hydrogels prepared with nonpurified blood plasma and compared with two-dimensional cultures. Despite the source, mesenchymal stem cells adhered through focal adhesions positive for vinculin and integrin αV in two dimensions, while focal adhesions could not be detected in fibrin hydrogels. Moreover, some cells could not spread and stay rounded. The proportions of elongated and round phenotypes varied, with placenta mesenchymal stem cells having the lowest percentage of elongated cells (~10%). Mesenchymal stem cells degraded fibrin at distinct rates, and placenta mesenchymal stem cells had the strongest fibrinolytic activity, which was achieved principally through the plasminogen–plasmin axis. These findings might have clinical implications in tissue engineering and wound healing therapy.

Intravascular Mesenchymal Stromal/Stem Cell Therapy Product Diversification: Time for New Clinical Guidelines

Intravascular infusion is the most popular route for therapeutic multipotent mesenchymal stromal/stem cell (MSC) delivery in hundreds of clinical trials. Meta-analysis has demonstrated that bone marrow MSC infusion is safe. It is not clear if this also applies to diverse new cell products derived from other sources, such as adipose and perinatal tissues. Different MSC products display varying levels of highly procoagulant tissue factor (TF) and may adversely trigger the instant blood-mediated inflammatory reaction (IBMIR). Suitable strategies for assessing and controlling hemocompatibility and optimized cell delivery are crucial for the development of safer and more effective MSC therapies.