Mesenchymal stem cells reverse thymus aging by reprogramming the DNA methylation of thymic epithelial cells

Background

A decrease in the number and activity of thymic epithelial cells (TECs) is an important factor in thymic degeneration. Mesenchymal stem cells (MSCs) treating thymic ageing is a promising strategy, but the DNA methylation modification mechanism in TECs remains unclear.

Methods

Aged rhesus monkeys were treated with MSCs to establish a thymic senescence model, and hematoxylin-eosin (HE) staining, immunofluorescence staining, and ELISA were performed to observe the structure and function of the thymus. TEC aging model and MSCs co-culture system were established to detect DNA methylation modification and transcriptomic changes, correlation analysis between transcription factor methylation and mRNA expression, and q-PCR, immunofluorescence staining, and Western blot were used to identified key genes.

Results

MSCs improved the structure and function of thymus in elderly macaque monkeys; reduced the expression levels of β-Gal, P16, and P21; and increased the activity of aging TECs. There were 501 genes with increased methylation in the promoter region in the treated group compared with the untreated group, among which 23 genes were involved in the negative regulation of cell growth, proliferation and apoptosis, while 591 genes had decreased methylation, among which 37 genes were associated with promoting cell growth and proliferation and inhibiting apoptosis. Furthermore, 66 genes showed a negative correlation between promoter methylation levels and gene transcription; specifically, PDE5A, DUOX2, LAMP1 and SVIL were downregulated with increased methylation, inhibiting growth and development, while POLR3G, PGF, CHTF18, KRT17, FOXJ1, NGF, DYRK3, LRP8, CDT1, PRELID1, F2R, KNTC1 and TRIM3 were upregulated with decreased methylation, promoting cell growth.

Conclusion

MSCs improve the structure and function of aged thymus, which involves the regulation of DNA methylation profiles and a decrease in the methylation level of the transcription factor NGF to specifically upregulate KRT17 and FOXJ1 to promote the proliferation of TECs.

Therapeutic trends of priming mesenchymal stem cells: A bibliometric analysis

Mesenchymal stem cells (MSCs) have gained substantial attention in regenerative medicine due to their multilineage differentiation potential and immunomodulatory capabilities. MSCs have demonstrated therapeutic promise in numerous preclinical and clinical studies across a variety of diseases, including neurodegenerative disorders, cardiovascular diseases, and autoimmune conditions. Recently, priming MSCs has emerged as a novel strategy to enhance their therapeutic efficacy by preconditioning them for optimal survival and function in challenging in vivo environments. This study presented a comprehensive bibliometric analysis of research activity in the field of priming mesenchymal stem cells (MSCs) from 2003 to 2023. Utilizing a dataset of 585 documents, we explored research trends, leading authors and countries, productive journals, and frequently used keywords. We also explored priming strategies to augment the therapeutic efficacy of MSCs. Our findings show increasing research productivity with a peak in 2019, identified the United States as the leading contributor, and highlighted WANG JA as the most prolific author. The most published journal was Stem Cell Research & Therapy. Keyword analysis revealed core research areas emerging hotspots, while coword and cited sources visualizations elucidated the conceptual framework and key information sources. Further studies are crucial to advance the translation of primed MSCs from bench to bedside, potentially revolutionizing the landscape of regenerative medicine.

Mesenchymal stem cells in autoimmune disease: A systematic review and meta-analysis of pre-clinical studies

Mesenchymal Stem Cells (MSCs) are of interest in the clinic because of their immunomodulation capabilities, capacity to act upstream of inflammation, and ability to sense metabolic environments. In standard physiologic conditions, they play a role in maintaining the homeostasis of tissues and organs; however, there is evidence that they can contribute to some autoimmune diseases. Gaining a deeper understanding of the factors that transition MSCs from their physiological function to a pathological role in their native environment, and elucidating mechanisms that reduce their therapeutic relevance in regenerative medicine, is essential. We conducted a Systematic Review and Meta-Analysis of human MSCs in preclinical studies of autoimmune disease, evaluating 60 studies that included 845 patient samples and 571 control samples. MSCs from any tissue source were included, and the study was limited to four autoimmune diseases: multiple sclerosis, rheumatoid arthritis, systemic sclerosis, and lupus. We developed a novel Risk of Bias tool to determine study quality for in vitro studies. Using the International Society for Cell & Gene Therapy's criteria to define an MSC, most studies reported no difference in morphology, adhesion, cell surface markers, or differentiation into bone, fat, or cartilage when comparing control and autoimmune MSCs. However, there were reported differences in proliferation. Additionally, 308 biomolecules were differentially expressed, and the abilities to migrate, invade, and form capillaries were decreased. The findings from this study could help to explain the pathogenic mechanisms of autoimmune disease and potentially lead to improved MSC-based therapeutic applications.

The potency of mesenchymal stem/stromal cells: does donor sex matter?

Mesenchymal stem/stromal cells (MSCs) are a promising therapeutic tool in cell therapy and tissue engineering because of their multi-lineage differentiation capacity, immunomodulatory effects, and tissue protective potential. To achieve optimal results as a therapeutic tool, factors affecting MSC potency, including but not limited to cell source, donor age, and cell batch, have been investigated. Although the sex of the donor has been attributed as a potential factor that can influence MSC potency and efficacy, the impact of donor sex on MSC characteristics has not been carefully investigated. In this review, we summarize published studies demonstrating donor-sex-related MSC heterogeneity and emphasize the importance of disclosing donor sex as a key factor affecting MSC potency in cell therapy.

Silymarin and MSC-exosomes ameliorate thioacetamide-evoked renal fibrosis by inhibiting TGF-β/SMAD pathway in rats

BACKGROUND

TGF-β1 and SMAD3 are particularly pathogenic in the progression of renal fibrosis.

AIM

This study aimed to evaluate the kidney protective potentials of silymarin (SM) and exosomes of mesenchymal stem cells against the nephrotoxin thioacetamide (TAA) in rats.

METHODS

32 female rats were randomly assigned into four groups: the control group, the TAA group, the TAA + SM group, and the TAA + Exosomes group. The kidney homogenates from all groups were examined for expression levels of TGF-β receptors I and II using real-time PCR, expression levels of collagen type I and CTGF proteins using ELISA, and the expression levels of nuclear SMAD2/3/4, cytoplasmic SMAD2/3, and cytoplasmic SMAD4 proteins using the western blot technique.

RESULTS

Compared to the control group, the injection of TAA resulted in a significant increase in serum levels of urea and creatinine, gene expression levels of TβRI and TβRII, protein expression levels of both collagen I and CTGF proteins, cytoplasmic SMAD2/3 complex, and nuclear SMAD2/3/4 (p-value < 0.0001), with significantly decreased levels of the co-SMAD partner, SMAD4 (p-value < 0.0001). Those effects were reversed considerably in both treatment groups, with the superiority of the exosomal treatment regarding the SMAD proteins and the expression levels of the TβRI gene, collagen I, and CTGF proteins returning to near-control values (p-value > 0.05).

CONCLUSION

Using in vitro and in vivo experimental approaches, the research discovered a reno-protective role of silymarin and exosomes of BM-MSCs after thioacetamide-induced renal fibrosis in rats, with the advantage of exosomes.

Xbp1 promotes odontoblastic differentiation through modulating mitochondrial homeostasis

Odontoblast differentiation depends on the orderly recruitment of transcriptional factors (TFs) in the transcriptional regulatory network. The depletion of crucial TFs disturbs dynamic alteration of the chromatin landscape and gene expression profile, leading to developmental defects. Our previous studies have revealed that the basic leucine zipper (bZIP) TF family is crucial in odontoblastic differentiation, but the function of bZIP TF family member XBP1 is still unknown. Here, we showed the stage-specific expression patterns of the spliced form Xbp1s during tooth development. Elevated Xbp1 expression and nuclear translocation of XBP1S in mesenchymal stem cells (MSCs) were induced by differentiation medium in vitro. Diminution of Xbp1 expression impaired the odontogenic differentiation potential of MSCs. The further integration of ATAC-seq and RNA-seq identified Hspa9 as a direct downstream target, an essential mitochondrial chaperonin gene that modulated mitochondrial homeostasis. The amelioration of mitochondrial dysfunction rescued the impaired odontogenic differentiation potential of MSCs caused by the diminution of Xbp1. Furthermore, the overexpression of Hspa9 rescued Xbp1-deficient defects in odontoblastic differentiation. Our study illustrates the crucial role of Xbp1 in odontoblastic differentiation via modulating mitochondrial homeostasis and brings evidence to the therapy of mitochondrial diseases caused by genetic defects.

The Role of Bioceramics for Bone Regeneration: History, Mechanisms, and Future Perspectives

Osteoporosis is a skeletal disorder marked by compromised bone integrity, predisposing individuals, particularly older adults and postmenopausal women, to fractures. The advent of bioceramics for bone regeneration has opened up auspicious pathways for addressing osteoporosis. Research indicates that bioceramics can help bones grow back by activating bone morphogenetic protein (BMP), mitogen-activated protein kinase (MAPK), and wingless/integrated (Wnt)/β-catenin pathways in the body when combined with stem cells, drugs, and other supports. Still, bioceramics have some problems, such as not being flexible enough and prone to breaking, as well as difficulties in growing stem cells and discovering suitable supports for different bone types. While there have been improvements in making bioceramics better for healing bones, it is important to keep looking for new ideas from different areas of medicine to make them even better. By conducting a thorough scrutiny of the pivotal role bioceramics play in facilitating bone regeneration, this review aspires to propel forward the rapidly burgeoning domain of scientific exploration. In the end, this appreciation will contribute to the development of novel bioceramics that enhance bone regrowth and offer patients with bone disorders alternative treatments.

Clinical results in patients affected by moderate-severe knee osteoarthritis and treated with micro-fragmented adipose tissue: the therapeutic effects on symptomatology

Osteoarthrosis is a degenerative musculoskeletal disease that presents a major public health problem, due to the increasing average age of the active population, as well as the increasing percentage of obesity or overweight of the general population. New therapeutic approaches have been developed, such as regenerative medicine that uses mesenchymal stromal cells taken from adipose tissue. This study analyzed the clinical potential benefits of using autologous adipose tissue to treat patients with moderate-severe knee osteoarthritis.In 2021, a total of 50 knees, affected by moderate-severe knee osteoarthritis, were treated with an intra-articular injection of micro-fragmented subcutaneous adipose tissue. Patients were submitted to the KOOS questionnaire before the operation and one year after the operation and VAS pain score at time 0, 3, 6, 12 months.Of the 50 patients treated, 2 patients were excluded from the study. Of the remaining 48 patients, improvements have been achieved in all subclasses of KOOS. In particular, VAS score proves that improvements are more considerable starting from the 3rd month after surgery.The results obtained in this study show the safety and potential benefit of the use of autologous micro-fragmented adipose on people who are affected by moderate-severe knee osteoarthritis.

Irisin influences the in vitro differentiation of human mesenchymal stromal cells, promoting a tendency toward beiging adipogenesis

Mammals exhibit two distinct types of adipose depots: white adipose tissue (WAT) and brown adipose tissue (BAT). While WAT primarily functions as a site for energy storage, BAT serves as a thermogenic tissue that utilizes energy and glucose consumption to regulate core body temperature. Under specific stimuli such as exercise, cold exposure, and drug treatment, white adipocytes possess a remarkable ability to undergo transdifferentiation into brown-like cells known as beige adipocytes. This transformation process, known as the "browning of WAT," leads to the acquisition of new morphological and physiological characteristics by white adipocytes. We investigated the potential role of Irisin, a 12 kDa myokine that is secreted in mice and humans by skeletal muscle after physical activity, in inducing the browning process in mesenchymal stromal cells (MSCs). A subset of the MSCs possesses the remarkable capability to differentiate into different cell types such as adipocytes, osteocytes, and chondrocytes. Consequently, comprehending the effects of Irisin on MSC biology becomes a crucial factor in investigating antiobesity medications. In our study, the primary objective is to evaluate the impact of Irisin on various cell types engaged in distinct stages of the differentiation process, including stem cells, committed precursors, and preadipocytes. By analyzing the effects of Irisin on these specific cell populations, our aim is to gain a comprehensive understanding of its influence throughout the entire differentiation process, rather than solely concentrating on the final differentiated cells. This approach enables us to obtain insights into the broader effects of Irisin on the cellular dynamics and mechanisms involved in adipogenesis.

Multifunctional Hydrogel of Recombinant Humanized Collagen Loaded with MSCs and MnO2 Accelerates Chronic Diabetic Wound Healing

Chronic wound repair is a clinical treatment challenge. The development of multifunctional hydrogels is of great significance in the key aspects of treating chronic wounds, including reducing oxidative stress, promoting angiogenesis, and improving the natural remodeling of extracellular matrix and immune regulation. In this study, we prepared a composite hydrogel, sodium alginate (SA)@MnO2/recombinant humanized collagen III (RHC)/mesenchymal stem cells (MSCs), composed of SA, MnO2 nanoparticles, RHC, and MSCs. The hydrogel has high mechanical properties and good biocompatibility. In vitro, SA@MnO2/RHC/MSCs hydrogel effectively enhanced the formation of intricate tubular structures and angiogenesis and showed synergistic effects on cell proliferation and migration. In vivo, the SA@MnO2/RHC/MSCs hydrogel enhanced diabetes wound healing, rapid re-epithelization, favorable collagen deposition, and abundant wound angiogenesis. These findings demonstrated that the combined effects of SA, MnO2, RHC, and MSCs synergistically accelerate healing, resulting in a reduced healing time. These observed healing effects demonstrated the potential of this multifunctional hydrogel to transform chronic wound care and improve patient outcomes.

3D Printed Conductive Hydrogel Patch Incorporated with MSC@GO for Efficient Myocardial Infarction Repair

Myocardial infarction (MI) results in an impaired heart function. Conductive hydrogel patch-based therapy has been considered as a promising strategy for cardiac repair after MI. In our study, we fabricated a three-dimensional (3D) printed conductive hydrogel patch made of fibrinogen scaffolds and mesenchymal stem cells (MSCs) combined with graphene oxide (GO) flakes (MSC@GO), capitalizing on GO's excellent mechanical property and electrical conductivity. The MSC@GO hydrogel patch can be attached to the epicardium via adhesion to provide strong electrical integration with infarcted hearts, as well as mechanical and regeneration support for the infarcted area, thereby up-regulating the expression of connexin 43 (Cx43) and resulting in effective MI repair in vivo. In addition, MI also triggers apoptosis and damage of cardiomyocytes (CMs), hindering the normal repair of the infarcted heart. GO flakes exhibit a protective effect against the apoptosis of implanted MSCs. In the mouse model of MI, MSC@GO hydrogel patch implantation supported cardiac repair by reducing cell apoptosis, promoting gap connexin protein Cx43 expression, and then boosting cardiac function. Together, this study demonstrated that the conductive hydrogel patch has versatile conductivity and mechanical support function and could therefore be a promising candidate for heart repair.

Cause and chondroprotective effects of prostaglandin E2 secretion during mesenchymal stromal cell chondrogenesis

Mesenchymal stromal cells (MSCs) that are promising for cartilage tissue engineering secrete high amounts of prostaglandin E2 (PGE2), an immunoactive mediator involved in endochondral bone development. This study aimed to identify drivers of PGE2 and its role in the inadvertent MSC misdifferentiation into hypertrophic chondrocytes. PGE2 release, which rose in the first three weeks of MSC chondrogenesis, was jointly stimulated by endogenous BMP, WNT, and hedgehog activity that supported the exogenous stimulation by TGF-β1 and insulin to overcome the PGE2 inhibition by dexamethasone. Experiments with PGE2 treatment or the inhibitor celecoxib or specific receptor antagonists demonstrated that PGE2, although driven by prohypertrophic signals, exerted broad autocrine antihypertrophic effects. This chondroprotective effect makes PGE2 not only a promising option for future combinatorial approaches to direct MSC tissue engineering approaches into chondral instead of endochondral development but could potentially have implications for the use of COX-2-selective inhibitors in osteoarthritis pain management.

Single-Cell RNA Sequencing Reveals Repair Features of Human Umbilical Cord Mesenchymal Stromal Cells

RATIONALE

The chronic lung disease bronchopulmonary dysplasia (BPD) is the most severe complication of extreme prematurity. BPD results in impaired lung alveolar and vascular development and long-term respiratory morbidity, for which only supportive therapies exist. Umbilical cord-derived mesenchymal stromal cells (UC-MSCs) improve lung structure and function in experimental BPD. Results of clinical trials with MSCs for many disorders do not yet match the promising preclinical studies. A lack of specific criteria to define functionally distinct MSCs persists.

OBJECTIVES

To determine and correlate single-cell UC-MSC transcriptomic profile with therapeutic potential.

METHODS

UC-MSCs from five term donors and human neonatal dermal fibroblasts (HNDFs, control cells of mesenchymal origin) transcriptomes were investigated by single-cell RNA sequencing analysis (scRNA-seq). The lung-protective effect of UC-MSCs with a distinct transcriptome and control HNDFs was tested in vivo in hyperoxia-induced neonatal lung injury in rats.

MEASUREMENTS AND MAIN RESULTS

UC-MSCs showed limited transcriptomic heterogeneity, but were different from HNDFs. Gene ontology enrichment analysis revealed distinct - progenitor-like and fibroblast-like - UC-MSC subpopulations. Only the treatment with progenitor-like UC-MSCs improved lung function and structure and attenuated pulmonary hypertension in hyperoxia-exposed rat pups. Moreover, scRNA-seq identified major histocompatibility complex class I as a molecular marker of non-therapeutic cells and associated with decreased lung retention.

CONCLUSIONS

UC-MSCs with a progenitor-like transcriptome, but not with a fibroblast-like transcriptome, provide lung protection in experimental BPD. High expression of major histocompatibility complex class I is associated with reduced therapeutic benefit. scRNA-seq may be useful to identify subsets of MSCs with superior repair capacity for clinical application.

Fluid shear force and hydrostatic pressure jointly promote osteogenic differentiation of BMSCs by activating YAP1 and NFAT2

Natural bone tissue features a complex mechanical environment, with cells responding to diverse mechanical stimuli, including fluid shear stress (FSS) and hydrostatic pressure (HP). However, current in vitro experiments commonly employ a singular mechanical stimulus to simulate the mechanical environment in vivo. The understanding of the combined effects and mechanisms of multiple mechanical stimuli remains limited. Hence, this study constructed a mechanical stimulation device capable of simultaneously applying FSS and HP to cells. This study investigated the impact of FSS and HP on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and examined the distinctions and interactions between the two mechanisms. The results demonstrated that both FSS and HP individually enhanced the osteogenic differentiation of BMSCs, with a more pronounced effect observed through their combined application. BMSCs responded to external FSS and HP stimulation through the integrin-cytoskeleton and Piezo1 ion channel respectively. This led to the activation of downstream biochemical signals, resulting in the dephosphorylation and nuclear translocation of the intracellular transcription factors Yes Associated Protein 1 (YAP1) and nuclear factor of activated T cells 2 (NFAT2). Activated YAP1 could bind to NFAT2 to enhance transcriptional activity, thereby promoting osteogenic differentiation of BMSCs more effectively. This study highlights the significance of composite mechanical stimulation in BMSCs' osteogenic differentiation, offering guidance for establishing a complex mechanical environment for in vitro functional bone tissue construction.

Caught in action: how MSCs modulate atherosclerotic plaque

Atherosclerosis (AS) is a medical condition marked by the stiffening and constriction of the arteries. This is caused by the accumulation of plaque, a substance made up of fat, cholesterol, calcium, and other elements present in the blood. Over time, this plaque solidifies and constricts the arteries, restricting the circulation of oxygen-rich blood to the organs and other body parts. The onset and progression of AS involve a continuous inflammatory response, including the infiltration of inflammatory cells, foam cells derived from monocytes/macrophages, and inflammatory cytokines and chemokines. Mesenchymal stromal cells (MSCs), a type of multipotent stem cells originating from various body tissues, have recently been demonstrated to have a protective and regulatory role in diseases involving inflammation. Consequently, the transplantation of MSCs is being proposed as a novel therapeutic strategy for atherosclerosis treatment. This mini-review intends to provide a summary of the regulatory effects of MSCs at the plaque site to lay the groundwork for therapeutic interventions.

Mesenchymal stem cell-based therapies for treating well-studied neurological disorders: a systematic review

Background

Millions of people across the globe are affected by conditions like Amyotrophic Lateral Sclerosis (ALS), Parkinson's Disease (PD), Multiple Sclerosis (MS), Spinal Cord Injury (SCI), and Traumatic Brain Injury (TBI), although most occurrences are common in the elderly population. This systematic review aims to highlight the safety of the procedures, their tolerability, and efficacy of the available therapies conducted over the years using mesenchymal stem cells (MSCs) in treating the neurological conditions mentioned above.

Methods

PubMed was used to search for published data from clinical trials performed using mesenchymal stem cells. Studies that provided the necessary information that mentioned the efficacy and adverse effects of the treatment in patients were considered for this review.

Results

In total, 43 manuscripts were selected after a strategic search, and these studies have been included in this systematic review. Most included studies reported the safety of the procedures used and the treatment's good tolerability, with mild adverse events such as fever, headache, mild pain at the injection site, or nausea being common. A few studies also reported death of some patients, attributed to the progression of the disease to severe stages before the treatment. Other severe events, such as respiratory or urinary infections reported in some studies, were not related to the treatment. Different parameters were used to evaluate the efficacy of the treatment based on the clinical condition of the patient.

Conclusion

Mesenchymal stem cells transplantation has so far proven to be safe and tolerable in select studies and patient types. This systematic review includes the results from the 43 selected studies in terms of safety and tolerability of the procedures, and several adverse events and therapeutic benefits during the follow-up period after administration of MSCs.

Wnt16 Increases Bone-to-Implant Contact in an Osteopenic Rat Model by Increasing Proliferation and Regulating the Differentiation of Bone Marrow Stromal Cells

Osseointegration is a complex biological cascade that regulates bone regeneration after implant placement. Implants possessing complex multiscale surface topographies augment this regenerative process through the regulation of bone marrow stromal cells (MSCs) that are in contact with the implant surface. One pathway regulating osteoblastic differentiation is Wnt signaling, and upregulation of non-canonical Wnts increases differentiation of MSCs on these titanium substrates. Wnt16 is a non-canonical Wnt shown to regulate bone morphology in mouse models. This study evaluated the role of Wnt16 during surface-mediated osteoblastic differentiation of MSCs in vitro and osseointegration in vivo. MSCs were cultured on Ti substrates with different surface properties and non-canonical Wnt expression was determined. Subsequently, MSCs were cultured on Ti substrates +/-Wnt16 (100 ng/mL) and anti-Wnt16 antibodies (2 μg/mL). Wnt16 expression was increased in cells grown on microrough surfaces that were processed to be hydrophilic and have nanoscale roughness. However, treatment MSCs on these surfaces with exogenous rhWnt16b increased total DNA content and osteoprotegerin production, but reduced osteoblastic differentiation and production of local factors necessary for osteogenesis. Addition of anti-Wnt16 antibodies blocked the inhibitor effects of Wnt16. The response to Wnt16 was likely independent of other osteogenic pathways like Wnt11-Wnt5a signaling and semaphorin 3a signaling. We used an established rat model of cortical and trabecular femoral bone impairment following botox injections (2 injections of 8 units/leg each, starting and maintenance doses) to assess Wnt16 effects on whole bone morphology and implant osseointegration. Wnt16 injections did not alter whole bone morphology significantly (BV/TV, cortical thickness, restoration of trabecular bone) but were effective at increasing cortical bone-to-implant contact during impaired osseointegration in the botox model. The mechanical quality of the increased bone was not sufficient to rescue the deleterious effects of botox. Clinically, these results are important to understand the interaction of cortical and trabecular bone during implant integration. They suggest a role for Wnt16 in modulating bone remodeling by reducing osteoclastic activity. Targeted strategies to temporally regulate Wnt16 after implant placement could be used to improve osseointegration by increasing the net pool of osteoprogenitor cells.

Single cell RNA-seq identifies a FOS/JUN-related monocyte signature associated with clinical response of heart failure patients with mesenchymal stem cell therapy

Heart failure (HF) is a serious global health issue that demands innovative treatment approaches. In this study, we collected samples from 4 HF patients before and after MSC therapy and performed scRNA-seq. After the MSC therapy, the proportion of CD14+ monocytes decreased significantly in both the treatment response and non-response groups, with a more pronounced decrease in the treatment response group. The therapy-response and non-response group were clearly separated in the UMAP plot, while the CD14+ monocytes in the therapy-response group before and after MSC therapy were very similar, but there were significant differences in the non-response group. By further performing NMF analysis, we identified 11 subsets of CD14+ monocytes. More importantly, we identified a therapy-related CD14+ monocyte subpopulation. The predictive model based on CD14+ monocytes constructed by machine learning algorithms showed good performance. Moreover, genes such as FOS were highly enriched in the therapy-related CD14+ monocytes. The SCENIC analysis revealed potential regulatory factors for this treatment-responsive CD14+ monocytes, and FOS/JUN were identified as potential core indicators/regulators. Finally, HF patients were divided into three groups by NMF analysis, and the therapy-responsive CD14+ monocyte characteristics were differentially activated among the three groups. Together, this study identifies treatment-responsive CD14+ monocytes as a crucial biomarker for assessing the suitability of MSC therapy and determining which HF patients could benefit from it. This provides new clues for further investigating the therapeutic mechanisms of MSC therapy, offering beneficial insights for personalized treatment and improving prognosis in HF patients.

A division-of-labor mode contributes to the cardioprotective potential of mesenchymal stem/stromal cells in heart failure post myocardial infarction

Background

Treatment of heart failure post myocardial infarction (post-MI HF) with mesenchymal stem/stromal cells (MSCs) holds great promise. Nevertheless, 2-dimensional (2D) GMP-grade MSCs from different labs and donor sources have different therapeutic efficacy and still in a low yield. Therefore, it is crucial to increase the production and find novel ways to assess the therapeutic efficacy of MSCs.

Materials and methods

hUC-MSCs were cultured in 3-dimensional (3D) expansion system for obtaining enough cells for clinical use, named as 3D MSCs. A post-MI HF mouse model was employed to conduct in vivo and in vitro experiments. Single-cell and bulk RNA-seq analyses were performed on 3D MSCs. A total of 125 combination algorithms were leveraged to screen for core ligand genes. Shinyapp and shinycell workflows were used for deploying web-server.

Result

3D GMP-grade MSCs can significantly and stably reduce the extent of post-MI HF. To understand the stable potential cardioprotective mechanism, scRNA-seq revealed the heterogeneity and division-of-labor mode of 3D MSCs at the cellular level. Specifically, scissor phenotypic analysis identified a reported wound-healing CD142+ MSCs subpopulation that is also associated with cardiac protection ability and CD142- MSCs that is in proliferative state, contributing to the cardioprotective function and self-renewal, respectively. Differential expression analysis was conducted on CD142+ MSCs and CD142- MSCs and the differentially expressed ligand-related model was achieved by employing 125 combination algorithms. The present study developed a machine learning predictive model based on 13 ligands. Further analysis using CellChat demonstrated that CD142+ MSCs have a stronger secretion capacity compared to CD142- MSCs and Flow cytometry sorting of the CD142+ MSCs and qRT-PCR validation confirmed the significant upregulation of these 13 ligand factors in CD142+ MSCs.

Conclusion

Clinical GMP-grade 3D MSCs could serve as a stable cardioprotective cell product. Using scissor analysis on scRNA-seq data, we have clarified the potential functional and proliferative subpopulation, which cooperatively contributed to self-renewal and functional maintenance for 3D MSCs, named as "division of labor" mode of MSCs. Moreover, a ligand model was robustly developed for predicting the secretory efficacy of MSCs. A user-friendly web-server and a predictive model were constructed and available (https://wangxc.shinyapps.io/3D_MSCs/).

Mesenchymal stem/stromal cells from human pluripotent stem cell-derived brain organoid enhance the ex vivo expansion and maintenance of hematopoietic stem/progenitor cells

BACKGROUND

Mesenchymal stem/stromal cells (MSCs) are of great therapeutic value due to their role in maintaining the function of hematopoietic stem/progenitor cells (HSPCs). MSCs derived from human pluripotent stem cells represent an ideal alternative because of their unlimited supply. However, the role of MSCs with neural crest origin derived from HPSCs on the maintenance of HSPCs has not been reported.

METHODS

Flow cytometric analysis, RNA sequencing and differentiation ability were applied to detect the characteristics of stromal cells from 3D human brain organoids. Human umbilical cord blood CD34+ (UCB-CD34+) cells were cultured in different coculture conditions composed of stromal cells and umbilical cord MSCs (UC-MSCs) with or without a cytokine cocktail. The hematopoietic stroma capacity of stromal cells was tested in vitro with the LTC-IC assay and in vivo by cotransplantation of cord blood nucleated cells and stroma cells into immunodeficient mice. RNA and proteomic sequencing were used to detect the role of MSCs on HSPCs.

RESULTS

The stromal cells, derived from both H1-hESCs and human induced pluripotent stem cells forebrain organoids, were capable of differentiating into the classical mesenchymal-derived cells (osteoblasts, chondrocytes, and adipocytes). These cells expressed MSC markers, thus named pluripotent stem cell-derived MSCs (pMSCs). The pMSCs showed neural crest origin with CD271 expression in the early stage. When human UCB-CD34+ HSPCs were cocultured on UC-MSCs or pMSCs, the latter resulted in robust expansion of UCB-CD34+ HSPCs in long-term culture and efficient maintenance of their transplantability. Comparison by RNA sequencing indicated that coculture of human UCB-CD34+ HSPCs with pMSCs provided an improved microenvironment for HSC maintenance. The pMSCs highly expressed the Wnt signaling inhibitors SFRP1 and SFRP2, indicating that they may help to modulate the cell cycle to promote the maintenance of UCB-CD34+ HSPCs by antagonizing Wnt activation.

CONCLUSIONS

A novel method for harvesting MSCs with neural crest origin from 3D human brain organoids under serum-free culture conditions was reported. We demonstrate that the pMSCs support human UCB-HSPC expansion in vitro in a long-term culture and the maintenance of their transplantable ability. RNA and proteomic sequencing indicated that pMSCs provided an improved microenvironment for HSC maintenance via mechanisms involving cell-cell contact and secreted factors and suppression of Wnt signaling. This represents a novel method for large-scale production of MSCs of neural crest origin and provides a potential approach for development of human hematopoietic stromal cell therapy for treatment of dyshematopoiesis.

Cell therapy for retinal degenerative disorders: a systematic review and three-level meta-analysis

BACKGROUND

Retinal degenerative disorders (RDDs) cause vision loss by damaging retinal neurons and photoreceptors, affecting individuals of all ages. Cell-based therapy has emerged as an effective approach for the treatment of RDDs with promising results. This meta-analysis aims to comprehensively evaluate the efficacy of cell therapy in treating age-related macular degeneration (AMD), retinitis pigmentosa (RP), and Stargardt macular degeneration (SMD) as the most prevalent RDDs.

METHODS

PubMed, Scopus, Web of Science, and Embase were searched using keywords related to various retinal diseases and cell therapy treatments until November 25th, 2023. The studies' quality was evaluated using the Joanna Briggs Institute's (JBI) checklist for quasi-experimental studies. Visual acuity measured as LogMAR score was used as our main outcome. A three-level random-effect meta-analysis was used to explore the visual acuity in patients who received cell-based therapy. Heterogeneity among the included studies was evaluated using subgroup and sensitivity analyses. Moreover, meta-regression for the type of cells, year of publication, and mean age of participants were performed.

RESULTS

Overall, 8345 studies were retrieved by the search, and 39 met the eligibility criteria, out of which 18 studies with a total of 224 eyes were included in the meta-analysis. There were 12 studies conducted on AMD, 7 on SMD, and 2 on RP. Cell therapy for AMD showed significant improvement in LogMAR (p < 0.05). Also, cell therapy decreased the LogMAR score in SMD and RP (p < 0.01 and p < 0.0001, respectively). Across all conditions, no substantial publication bias was detected (p < 0.05).

CONCLUSION

The findings of the study highlight that the application of cell therapy can enhance the visual acuity in AMD, SMD, and RP.

Mesenchymal Stem Cells on Mortality in COVID-19 Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The Coronavirus disease-2019 (COVID-19) pandemic continues, and the death toll continues to surge. This meta-analysis aimed to determine the efficacy of mesenchymal stem cells (MSCs) on mortality in patients with COVID-19.

METHODS

A systematic search was made of PubMed, Embase, Cochrane Library, and clinicaltrials.gov, without language restrictions. Randomized controlled trials (RCTs) on treatment of COVID-19 with MSCs, compared with placebo or blank, were reviewed. Studies were pooled to risk ratios (RRs), with 95% confidence intervals (CIs).

RESULTS

Seventeen RCTs (enrolling 1019 participants) met the inclusion criteria. MSCs showed significant effect on 28-day mortality (RR 0.76, 95% CI 0.62 to 0.93; P = 0.008). There was no statistically significant difference in 60-day mortality (RR 0.87, 95% CI 0.70 to 1.09; P = 0.22), and 90-day mortality (RR 0.91, 95% CI 0.72 to 1.15; P = 0.44) between the two groups.

CONCLUSIONS

MSCs significantly reduced 28-day mortality in patients with COVID-19. The long-term effect of MSCs on mortality require further study.

Gastric cancer mesenchymal stem cells promote tumor glycolysis and chemoresistance by regulating B7H3 in gastric cancer cells

Despite surgical treatment combined with multidrug therapy having made some progress, chemotherapy resistance is the main cause of recurrence and death of gastric cancer (GC). Gastric cancer mesenchymal stem cells (GCMSCs) have been reported to be correlated with the limited efficacy of chemotherapy in GC, but the mechanism of GCMSCs regulating GC resistance needs to be further studied. The gene set enrichment analysis (GSEA) was performed to explore the glycolysis-related pathways heterogeneity across different cell subpopulations. Glucose uptake and lactate production assays were used to evaluate the importance of B7H3 expression in GCMSCs-treated GC cells. The therapeutic efficacy of oxaliplatin (OXA) and paclitaxel (PTX) was determined using CCK-8 and colony formation assays. Signaling pathways altered by GCMSCs-CM were revealed by immunoblotting. The expression of TNF-α in GCMSCs and bone marrow mesenchymal stem cells (BMMSCs) was detected by western blot analysis and qPCR. Our results showed that the OXA and PTX resistance of GC cells were significantly enhanced in the GCMSCs-CM treated GC cells. Acquired OXA and PTX resistance was characterized by increased cell viability for OXA and PTX, the formation of cell colonies, and decreased levels of cell apoptosis, which were accompanied by reduced levels of cleaved caspase-3 and Bax expression, and increased levels of Bcl-2, HK2, MDR1, and B7H3 expression. Blocking TNF-α in GCMSCs-CM, B7H3 knockdown or the use of 2-DG, a key enzyme inhibitor of glycolysis in GC cells suppressed the OXA and PTX resistance of GC cells that had been treated with GCMSCs-CM. This study shows that GCMSCs-CM derived TNF-α could upregulate the expression of B7H3 of GC cells to promote tumor chemoresistance. Our results provide a new basis for the treatment of GC.

Heparinized Acellular Hydrogels for Magnetically Induced Wound Healing Applications

The control of angiogenesis has the potential to be used for regulation of several pathological and physiological processes, which can be instrumental on the development of anticancer and wound healing therapeutical approaches. In this study, mesenchymal stem/stromal cells (MSCs) were seeded on magnetic-responsive gelatin, with or without heparin functionalization, and exposed to a static 0.08 T magnetic field (MF), for controlling their anti-inflammatory and angiogenic activity, with the aim of accelerating tissue healing. For the first time, it was examined how the amount of heparin and magnetic nanoparticles (MNPs) distributed on gelatin scaffolds affected the mechanical properties of the hydrogels and the morphology, proliferation, and secretome profiling of MSCs. The findings demonstrated that the addition of MNPs and heparin affects the hydrogel swelling capacity and renders distinct MSC proliferation rates. Additionally, MF acts as a topographical cue to guide MSCs alignment and increases the level of expression of specific genes and proteins that promote angiogenesis. The results also suggested that the presence of higher amounts of heparin (10 μg/cm3) interferes with the secretion and limits the capacity of angiogenic factors to diffuse through the hydrogel and into the culture medium. Ultimately, this study shows that acellular heparinized hydrogels efficiently retain the angiogenic growth factors released by magnetically stimulated MSCs thus rendering superior wound contraction (55.8% ± 0.4%) and cell migration rate (49.4% ± 0.4%), in comparison to nonheparinized hydrogels (35.2% ± 0.7% and 37.8% ± 0.7%, respectively). Therefore, these heparinized magnetic hydrogels can be used to facilitate angiogenesis in various forms of tissue damage including bone defects, skin wounds, and cardiovascular diseases, leading to enhanced tissue regeneration.

Effects of Spermine Synthase Deficiency in Mesenchymal Stromal Cells Are Rescued by Upstream Inhibition of Ornithine Decarboxylase

Despite the well-known relevance of polyamines to many forms of life, little is known about how polyamines regulate osteogenesis and skeletal homeostasis. Here, we report a series of in vitro studies conducted with human-bone-marrow-derived pluripotent stromal cells (MSCs). First, we show that during osteogenic differentiation, mRNA levels of most polyamine-associated enzymes are relatively constant, except for the catabolic enzyme spermidine/spermine N1-acetyltransferase 1 (SAT1), which is strongly increased at both mRNA and protein levels. As a result, the intracellular spermidine to spermine ratio is significantly reduced during the early stages of osteoblastogenesis. Supplementation of cells with exogenous spermidine or spermine decreases matrix mineralization in a dose-dependent manner. Employing N-cyclohexyl-1,3-propanediamine (CDAP) to chemically inhibit spermine synthase (SMS), the enzyme catalyzing conversion of spermidine into spermine, also suppresses mineralization. Intriguingly, this reduced mineralization is rescued with DFMO, an inhibitor of the upstream polyamine enzyme ornithine decarboxylase (ODC1). Similarly, high concentrations of CDAP cause cytoplasmic vacuolization and alter mitochondrial function, which are also reversible with the addition of DFMO. Altogether, these studies suggest that excess polyamines, especially spermidine, negatively affect hydroxyapatite synthesis of primary MSCs, whereas inhibition of polyamine synthesis with DFMO rescues most, but not all of these defects. These findings are relevant for patients with Snyder-Robinson syndrome (SRS), as the presenting skeletal defects-associated with SMS deficiency-could potentially be ameliorated by treatment with DFMO.

Regulation of inflammation during wound healing: the function of mesenchymal stem cells and strategies for therapeutic enhancement

A wound takes a long time to heal and involves several steps. Following tissue injury, inflammation is the primary cause of tissue regeneration and repair processes. As a result, the pathophysiological processes involving skin damage, healing, and remodeling depend critically on the control of inflammation. The fact that it is a feasible target for improving the prognosis of wound healing has lately become clear. Mesenchymal stem cells (MSCs) are an innovative and effective therapeutic option for wound healing due to their immunomodulatory and paracrine properties. By controlling the inflammatory milieu of wounds through immunomodulation, transplanted MSCs have been shown to speed up the healing process. In addition to other immunomodulatory mechanisms, including handling neutrophil activity and modifying macrophage polarization, there may be modifications to the activation of T cells, natural killer (NK) cells, and dendritic cells (DCs). Furthermore, several studies have shown that pretreating MSCs improves their ability to modulate immunity. In this review, we summarize the existing knowledge about how MSCs influence local inflammation in wounds by influencing immunity to facilitate the healing process. We also provide an overview of MSCs optimizing techniques when used to treat wounds.

Rutin promotes osteogenic differentiation of mesenchymal stem cells (MSCs) by increasing ECM deposition and inhibiting p53 expression

Mesenchymal stem cells (MSCs) are an important source of cells for bone regeneration. Although the utilization of MSCs along with growth factors and scaffolds is a beneficial clinical approach for bone tissue engineering, there is need for improvement on the effectiveness of MSC osteogenesis and differentiation. Rutin is a natural flavonoid and a major component for cell proliferation and bone development. However, studies on the mechanism through which rutin regulates osteogenesis and MSC differentiation are limited. Therefore, this study aimed to investigate the effect and mechanisms of rutin on osteogenic differentiation of MSCs. MSCs were extracted from umbilical cords and treated with rutin, followed by the examination of osteogenesis-related markers. Rutin treatment promoted the differentiation of MSCs towards the osteogenic lineage rather than the adipogenic lineage and increased the expression of osteogenic markers. RNA sequencing and bioinformatic analysis indicated that rutin regulated p53, a key gene in regulating the osteogenic differentiation of MSCs. Additionally, cellular experiments showed that rutin-induced decrease in p53 expression increased the formation of extracellular matrix (ECM) by promoting p65 phosphorylation and caspase-3 cleavage. Conclusively, this study demonstrates the importance of rutin in osteogenesis and indicates that rutin possesses potential pharmaceutical application for bone regeneration and bone tissue engineering.

Enhancing anti-tumor potential: low-intensity vibration suppresses osteosarcoma progression and augments MSCs' tumor-suppressive abilities

Rationale: Osteosarcoma (OS), a common malignant bone tumor, calls for the investigation of novel treatment strategies. Low-intensity vibration (LIV) presents itself as a promising option, given its potential to enhance bone health and decrease cancer susceptibility. This research delves into the effects of LIV on OS cells and mesenchymal stem cells (MSCs), with a primary focus on generating induced tumor-suppressing cells (iTSCs) and tumor-suppressive conditioned medium (CM). Methods: To ascertain the influence of vibration frequency, we employed numerical simulations and conducted experiments to determine the most effective LIV conditions. Subsequently, we generated iTSCs and CM through LIV exposure and assessed the impact of CM on OS cells. We also explored the underlying mechanisms of the tumor-suppressive effects of LIV-treated MSC CM, with a specific focus on vinculin (VCL). We employed cytokine array, RNA sequencing, and Western blot techniques to investigate alterations in cytokine profiles, transcriptomes, and tumor suppressor proteins. Results: Numerical simulations validated LIV frequencies within the 10-100 Hz range. LIV induced notable morphological changes in OS cells and MSCs, confirming its dual role in inhibiting OS cell progression and promoting MSC conversion into iTSCs. Upregulated VCL expression enhanced MSC responsiveness to LIV, significantly bolstering CM's efficacy. Notably, we identified tumor suppressor proteins in LIV-treated CM, including procollagen C endopeptidase enhancer (PCOLCE), histone H4 (H4), peptidylprolyl isomerase B (PPIB), and aldolase A (ALDOA). Consistently, cytokine levels decreased significantly in LIV-treated mouse femurs, and oncogenic transcript levels were downregulated in LIV-treated OS cells. Moreover, our study demonstrated that combining LIV-treated MSC CM with chemotherapy drugs yielded additive anti-tumor effects. Conclusions: LIV effectively impeded the progression of OS cells and facilitated the transformation of MSCs into iTSCs. Notably, iTSC-derived CM demonstrated robust anti-tumor properties and the augmentation of MSC responsiveness to LIV via VCL. Furthermore, the enrichment of tumor suppressor proteins within LIV-treated MSC CM and the reduction of cytokines within LIV-treated isolated bone underscore the pivotal tumor-suppressive role of LIV within the bone tumor microenvironment.

Fibroblasts inhibit osteogenesis by regulating nuclear-cytoplasmic shuttling of YAP in mesenchymal stem cells and secreting DKK1

BACKGROUND

Fibrous scars frequently form at the sites of bone nonunion when attempts to repair bone fractures have failed. However, the detailed mechanism by which fibroblasts, which are the main components of fibrous scars, impede osteogenesis remains largely unknown.

RESULTS

In this study, we found that fibroblasts compete with osteogenesis in both human bone nonunion tissues and BMP2-induced ectopic osteogenesis in a mouse model. Fibroblasts could inhibit the osteoblastic differentiation of mesenchymal stem cells (MSCs) via direct and indirect cell competition. During this process, fibroblasts modulated the nuclear-cytoplasmic shuttling of YAP in MSCs. Knocking down YAP could inhibit osteoblast differentiation of MSCs, while overexpression of nuclear-localized YAP-5SA could reverse the inhibition of osteoblast differentiation of MSCs caused by fibroblasts. Furthermore, fibroblasts secreted DKK1, which further inhibited the formation of calcium nodules during the late stage of osteogenesis but did not affect the early stage of osteogenesis. Thus, fibroblasts could inhibit osteogenesis by regulating YAP localization in MSCs and secreting DKK1.

CONCLUSIONS

Our research revealed that fibroblasts could modulate the nuclear-cytoplasmic shuttling of YAP in MSCs, thereby inhibiting their osteoblast differentiation. Fibroblasts could also secrete DKK1, which inhibited calcium nodule formation at the late stage of osteogenesis.

Future of low back pain: unravelling IVD components and MSCs' potential

Low back pain (LBP) mainly emerges from intervertebral disc (IVD) degeneration. However, the failing mechanism of IVD ́s components, like the annulus fibrosus (AF) and nucleus pulposus (NP), leading to IVD degeneration/herniation is still poorly understood. Moreover, the specific role of cellular populations and molecular pathways involved in the inflammatory process associated with IVD herniation remains to be highlighted. The limited knowledge of inflammation associated with the initial steps of herniation and the lack of suitable models to mimic human IVD ́s complexity are some of the reasons for that. It has become essential to enhance the knowledge of cellular and molecular key players for AF and NP cells during inflammatory-driven degeneration. Due to unique properties of immunomodulation and pluripotency, mesenchymal stem cells (MSCs) have attained diverse recognition in this field of bone and cartilage regeneration. MSCs therapy has been particularly valuable in facilitating repair of damaged tissues and may benefit in mitigating inflammation' degenerative events. Therefore, this review article conducts comprehensive research to further understand the intertwine between the mechanisms of action of IVD components and therapeutic potential of MSCs, exploring their characteristics, how to optimize their use and establish them safely in distinct settings for LPB treatment.

Enhancing Spermatogenesis in Non-obstructive Azoospermia through Mesenchymal Stem Cell Therapy

Stem cells hold great promise as novel and encouraging therapeutic tools in the treatment of degenerative disorders due to their differentiation potential while maintaining the capability to self-renewal and their unlimited ability to divide and regenerate tissue. A variety of different types of stem cells can be used in cell therapy. Among these, mesenchymal stem cell (MSC) therapy has gradually established itself as a novel method for treating damaged tissues that need restoration and renewal. Male infertility is an important health challenge affecting approximately 8-12% of people around the world. This abnormality can be caused by primary, congenital, acquired, or idiopathic reasons. Men with no sperm in their semen have a condition called azoospermia, caused by non-obstructive (NOA) causes and post-testicular obstructive causes. Accumulating evidence has shown that various types of MSCs can differentiate into germ cells and improve spermatogenesis in the seminiferous tubules of animal models. In addition, recent studies in animal models have exhibited that extracellular vesicles derived from MSCs can stimulate the progression of spermatogenesis and germ cell regeneration in the recipient testes. In spite of the fact that various improvements have been made in the treatment of azoospermia disorder in animal models by MSC or their extracellular vesicles, no clinical trials have been carried out to test their therapeutic effect on the NOA. In this review, we summarize the potential of MSC transplantation for treating infertility caused by NOA.

CD317+ MSCs expanded with chemically defined media have enhanced immunological anti-inflammatory activities

BACKGROUND

Although both preclinical and clinical studies have shown the great application potential of MSCs (mesenchymal stem/stromal cells) in treating many kinds of diseases, therapeutic inconsistency resulting from cell heterogeneity is the major stumbling block to their clinical applications. Cell population diversity and batch variation in the cell expansion medium are two major inducers of MSC heterogeneity.

METHODS

Cell population diversity was investigated through single-cell RNA sequencing analysis of human MSCs derived from the umbilical cord and expanded with fully chemically defined medium in the current study. Then, the MSC subpopulation with enhanced anti-inflammatory effects was studied in vitro and in vivo.

RESULTS

Our data showed that MSCs contain different populations with different functions, including subpopulations with enhanced functions of exosome secretion, extracellular matrix modification and responses to stimuli (regeneration and immune response). Among them, CD317+ MSCs have improved differentiation capabilities and enhanced immune suppression activities. Underlying mechanism studies showed that higher levels of TSG6 confer enhanced anti-inflammatory functions of CD317+ MSCs.

CONCLUSIONS

Thus, CD317+ MSCs might be a promising candidate for treating immunological disorder-related diseases.

Diverse Approaches toward Application of Dental Pulp Stem Cells from Human Permanent and Deciduous Teeth in the Treatment of Diabetes

BACKGROUND

Diabetes Mellitus is defined by hyperglycemia, a condition which is the result of defects in insulin secretion, insulin action, or both. Evidence suggest that islet transplantation is a promising treatment approach, but the shortage of sources of insulin-producing cells is a major problem. Ethical concerns and the limited availability of most stem cells have led scientists to concentrate on mesenchymal stem cells, which are found in stem cells niches of all organs of the body including dental tissues on which dental pulp stem cells (DPSCs) and stem cells from exfoliated deciduous teeth (SHED) are the easiest accessible sources.

HIGHLIGHTS

Generally, SHED show characteristics similar to DPSCs; however, its proliferative and clonogenic capacities are higher. It has been proved that these two types of dental mesenchymal stem cells are able to produce islet-like cells capable of insulin secretion. In this review, we discuss various conducted approaches on the application of DPSCs and SHED in the treatment of diseases associated with diabetes such as; pancreatic differentiation cocktails, 2D and 3D culture techniques, factors that affect pancreatic differentiation, in vivo studies (direct administration of DPSCs and SHED, administration of their secretome and encapsulation of their-derived insulin producing cells), clinical trials and future perspectives of these approaches.

CONCLUSION

Dental stem cell-based therapy has been considered as a promising therapeutic procedure for treatment of diabetes. Major advances in research on the derivation of insulin producing cells from DPSCs and SHED have enhanced our chance of re-establishing glucose-responsive insulin secretion in patients with diabetes.

Mechanosignaling YAP/TAZ-TEAD Axis Regulates the Immunomodulatory Properties of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) have gained significant attention in cell therapies due to their multipotency and immunomodulatory capacities. The transcriptional co-activators YAP/TAZ, central to the mechanotransduction system in MSCs, dominantly direct MSCs lineage commitment. However, their role in immunomodulation remains elusive. Accordingly, this present study aimed to investigate the role of mechanotransducer YAP/TAZ and their binding target transcriptional factor, TEAD, in the immunomodulatory capacities of human bone marrow-derived MSCs. Reducing YAP/TAZ activity by altering the matrix stiffness, disrupting the F-actin integrity with chemical inhibitors, or using siRNAs increased the expression of immunomodulatory genes, such as TSG-6 and IDO, upon TNF-α stimulation. Similarly, transfection of TEAD siRNA also increased the immunomodulatory capacities in MSCs. RNA-seq analysis and inhibition assays demonstrated that the immunomodulatory capacities caused by YAP/TAZ-TEAD axis disruption were due to the NF-κB signaling pathway activation. Then, we also evaluated the in vivo anti-inflammatory efficacy of MSCs in a dextran sulfate sodium (DSS)-induced mice colitis model. The administration of human MSCs transfected with TEAD siRNA, which exhibited enhanced immunomodulatory properties in vitro, significantly ameliorated inflammatory bowel disease symptoms, such as body weight loss and acute colon inflammation, in the DSS-induced mice colitis model. Our findings underscore the mechanosignaling YAP/TAZ-TEAD axis as a regulator of MSCs immunomodulation. Targeting these signaling pathways could herald promising MSCs-based therapies for immune disorders.

Mechanical Unloading Promotes Osteoclastic Differentiation and Bone Resorption by Modulating the MSC Secretome to Favor Inflammation

Aging, space flight, and prolonged bed rest have all been linked to bone loss, and no effective treatments are clinically available at present. Here, with the rodent hindlimb unloading (HU) model, we report that the bone marrow (BM) microenvironment was significantly altered, with an increased number of myeloid cells and elevated inflammatory cytokines. In such inflammatory BM, the osteoclast-mediated bone resorption was greatly enhanced, leading to a shifted bone remodeling balance that ultimately ends up with disuse-induced osteoporosis. Using Piezo1 conditional knockout (KO) mice (Piezo1fl/fl;LepRCre), we proved that lack of mechanical stimuli on LepR+ mesenchymal stem cells (MSCs) is the main reason for the pathological BM inflammation. Mechanically, the secretome of MSCs was regulated by mechanical stimuli. Inadequate mechanical load leads to increased production of inflammatory cytokines, such as interleukin (IL)-1α, IL-6, macrophage colony-stimulating factor 1 (M-CSF-1), and so on, which promotes monocyte proliferation and osteoclastic differentiation. Interestingly, transplantation of 10% cyclic mechanical stretch (CMS)-treated MSCs into HU animals significantly alleviated the BM microenvironment and rebalanced bone remodeling. In summary, our research revealed a new mechanism underlying mechanical unloading-induced bone loss and suggested a novel stem cell-based therapy to potentially prevent disuse-induced osteoporosis.

Multifaceted Characterization of Human Embryonic Stem Cell-Derived Mesenchymal Stem/Stromal Cells Revealed Amelioration of Acute Liver Injury in NOD-SCID Mice

Human embryonic stem cells (hESCs) are advantaged sources for large-scale and homogeneous mesenchymal stem/stromal cells (MSCs) generation. However, due to the limitations in high-efficiency procedures for hESC-MSCs induction, the systematic and detailed information of mesengenesis and early MSC development are largely obscure. In this study, we took advantage of the well-established twist-related protein 1 (TWIST1)-overexpressing hESCs and two small molecular cocktails (CHIR99021, decitabine) for high-efficient MSC induction. To assess the multidimensional biological and transcriptomic characteristics, we turned to cellular and molecular methods, such as flow cytometry (FCM), quantitative reverse transcription-polymerase chain reaction (qRT-PCR), in vitro tri-lineage differentiation, cytokine secretion analysis, in vivo transplantation for acute liver injury (ALI) management, and bioinformatics analyses (eg, gene ontology-biological processes [GO-BP], Kyoto Encyclopedia of Genes and Genomes [KEGG], HeatMap, and principal component analysis [PCA]). By combining TWIST1 overexpression (denoted as T) and the indicated small molecular cocktails (denoted as S), hESCs high-efficiently differentiated into MSCs (denoted as TS-MSCs, induced by T and S combination) within 2 weeks. TS-MSCs satisfied the criteria for MSC definition and revealed comparable tri-lineage differentiation potential and ameliorative efficacy upon ALI mice. According to RNA-sequencing (SEQ) analysis, we originally illuminated the gradual variations in gene expression pattern and the concomitant biofunctions of the programmed hESC-MSCs. Overall, our data indicated the feasibility of high-efficient generation of hESC-MSCs by TWIST1 and cocktail-based programming. The generated hESC-MSCs revealed multifaceted in vivo and in vitro biofunctions as adult BM-MSCs, which collectively suggested promising prospects in ALI management in future.

Mechanistic study of the Aldo-keto reductase family 1 member A1 in regulating mesenchymal stem cell fate decision toward adipogenesis and osteogenesis

AIMS

Akr1A1 is a glycolytic enzyme catalyzing the reduction of aldehyde to alcohol. This study aims to delineate the role of Akr1A1 in regulating the adipo-osteogenic lineage differentiation of mesenchymal stem cells (MSCs).

MAIN METHODS

MSCs derived from human bone marrow and Wharton Jelly together with gain- and loss-of-function analysis as well as supplementation with the S-Nitrosoglutathione reductase (GSNOR) inhibitor N6022 were used to study the function of Akr1A1 in controlling MSC lineage differentiation into osteoblasts and adipocytes.

KEY FINDINGS

Akr1A1 expression, PKM2 activity, and lactate production were found to be decreased in osteoblast-committed MSCs, but PGC-1α increased to induce mitochondrial oxidative phosphorylation. Increased Akr1A1 inhibited the SIRT1-dependent pathway for decreasing the expressions of PGC-1α and TAZ but increasing PPAR γ in adipocyte-committed MSCs, hence promoting glycolysis in adipogenesis. In contrast, Akr1A1 expression, PKM2 activity and lactate production were all increased in adipocyte-differentiated cells with decreased PGC-1α for switching energy utilization to glycolytic metabolism. Reduced Akr1A1 expression in osteoblast-committed cells relieves its inhibition of SIRT1-mediated activation of PGC-1α and TAZ for facilitating osteogenesis and mitochondrial metabolism.

SIGNIFICANCE

Several metabolism-involved regulators including Akr1A1, SIRT1, PPARγ, PGC-1α and TAZ were differentially expressed in osteoblast- and adipocyte-committed MSCs. More importantly, Akr1A1 was identified as a new key regulator for controlling the MSC lineage commitment in favor of adipogenesis but detrimental to osteogenesis. Such information should be useful to develop perspective new therapeutic agents to reverse the adipo-osteogenic differentiation of BMSCs, in a way to increase in osteogenesis but decrease in adipogenesis.

Recent progress in regenerative therapy for damaged salivary glands: From bench to bedside

OBJECTIVE

For functional restoration of salivary glands (SGs) injured by radiation therapy or Sjögren's syndrome (SS), various experimental approaches, such as gene therapy, tissue engineering, and cell-based therapy, have been proposed. This narrative review summarized recent progresses in research using cell-based therapies, including promising trials that could lead to bench-to-clinic applications.

METHODS

A literature review based on PubMed publications in the last two decades was performed to summarize progresses in cell-based therapies for SG dysfunction.

RESULTS

Over 100 experimental studies have shown the therapeutic potential of several types of cells, such as SG stem cells and mesenchymal stem cells, as well as effectively conditioned mononuclear cells, in both radiation injury and SS animal models. These therapies affect to slow fibrosis progression and stimulate tissue regeneration in atrophic glands. However, to date, only a total of seven studies have been developed to the stage of clinical study, showing the safety and preliminary efficacy.

CONCLUSION

To lead the radical effectiveness expected in cell-based therapy, advances in reverse translational research and in innovative experimental research, based on the findings of recent clinical studies, will be critical in the next decade.

JD-312 - A novel small molecule that facilitates cartilage repair and alleviates osteoarthritis progression

Background

The chondrogenic differentiation of mesenchymal stem cells (MSCs) to enhance cartilage repair and regeneration is a promising strategy to alleviate osteoarthritis (OA) progression.

Method

The potency of JD-312 in inducing chondrogenic differentiation of MSCs was assessed and verified. The efficacy of JD-312-treated MSCs was evaluated using a Sprague-Dawley rat DMM model. Additionally, the capacity of JD-312 to successfully recruit bone marrow-derived mesenchymal stem cells (BMSCs) for the treatment of OA in vitro was confirmed via intra-articular injection. The repair status of the articular cartilage was analyzed in vivo through histological examination.

Result

In this study, we identify JD-312 as a novel non-toxic small molecule that can promote chondrogenic differentiation in human umbilical cord-derived MSCs (hUCMSCs) and human bone marrow MSCS (hBMSCs) in vitro. We also show that transient differentiation of MSCs with JD-312 prior to in vivo administration remarkably improves the regeneration of cartilage and promotes Col2a1 and Acan expression in rat models of DMM, in comparison to kartogenin (KGN) pre-treatment or MSCs alone. Furthermore, direct intra-articular injection of JD-312 in murine model of OA showed reduced loss of articular cartilage and improved pain parameters. Lastly, we identified that the effects of JD-312 are at least in part mediated via upregulation of genes associated with the focal adhesion, PI3K-Akt signaling and the ECM-receptor interaction pathways, and specifically cartilage oligomeric matrix protein (COMP) may play a vital role.

Conclusion

Our study demonstrated that JD-312 showed encouraging repair effects for OA in vivo.

The translational potential of this article

Together, our findings demonstrate that JD-312 is a promising new therapeutic molecule for cartilage regeneration with clinical potential.

The expression mechanism of programmed cell death 1 ligand 1 and its role in immunomodulatory ability of mesenchymal stem cells

Programmed cell death 1 ligand 1 (PD-L1) is an important immunosuppressive molecule, which inhibits the function of T cells and other immune cells by binding to the receptor programmed cell death-1. The PD-L1 expression disorder plays an important role in the occurrence, development, and treatment of sepsis or other inflammatory diseases, and has become an important target for the treatment of these diseases. Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cells with multiple differentiation potential. In recent years, MSCs have been found to have a strong immunosuppressive ability and are used to treat various inflammatory insults caused by hyperimmune diseases. Moreover, PD-L1 is deeply involved in the immunosuppressive events of MSCs and plays an important role in the treatment of various diseases. In this review, we will summarize the main regulatory mechanism of PD-L1 expression, and discuss various biological functions of PD-L1 in the immune regulation of MSCs.

Synergistic Effect of Human Chorionic Gonadotropin and Granulocyte Colony Stimulating Factor in the Mobilization of HSPCs Improves Overall Survival After PBSCT in a Preclinical Murine Model. Are We Far Enough for Therapy?

Strategies to improve hematopoietic stem and progenitor cell (HSPC) mobilization from the bone marrow can have a pivotal role in addressing iatrogenic bone-marrow insufficiency from chemo(radio)therapy and overcoming peripheral blood stem cell transplantation (PBSCT) limitations such as insufficient mobilization. Granulocyte-colony stimulating factor (G-CSF) represents the standard mobilization strategy for HSPC and has done so for more than three decades since its FDA approval. Its association with non-G-CSF agents is often employed for difficult HSPC mobilization. However, obtaining a synergistic effect between the two classes is limited by different timing and mechanisms of action. Based on our previous in vitro results, we tested the mobilization potential of human chorionic gonadotropin (HCG), alone and in combination with G-CSF in vivo in a murine study. Our results show an improved mobilization capability of the combination, which seems to act synergistically in stimulating hematopoiesis. With the current understanding of the dynamics of HSPCs and their origins in more primitive cells related to the germline, new strategies to employ the mobilization of hematopoietic progenitors using chorionic gonadotropins could soon become clinical practice.

Exploring the Three-Dimensional Frontier: Advancements in MSC Spheroids and Their Implications for Breast Cancer and Personalized Regenerative Therapies

To more accurately replicate the in vivo three-dimensional (3D) mesenchymal stem cell (MSC) niche and enhance cellular phenotypes for superior in vivo treatments, MSC functionalization through in vitro 3D culture approaches has gained attention. The organization of MSCs in 3D spheroids results in altered cell shape, cytoskeleton rearrangement, and polarization. Investigations have revealed that the survival and secretory capability of MSCs are positively impacted by moderate hypoxia within the inner zones of MSC spheroids. The spheroid hypoxic microenvironment enhances the production of angiogenic and anti-apoptotic molecules, including HGF, VEGF, and FGF-2. Furthermore, it upregulates the expression of hypoxia-adaptive molecules such as CXCL12 and HIF-1, inhibiting MSC death. The current review focuses on the latest developments in fundamental and translational research concerning three-dimensional MSC systems. This emphasis extends to the primary benefits and potential applications of MSC spheroids, particularly in the context of breast cancer and customized regenerative therapies.

MiR-146b-5p enriched bioinspired exosomes derived from fucoidan-directed induction mesenchymal stem cells protect chondrocytes in osteoarthritis by targeting TRAF6

Osteoarthritis (OA) is a common degenerative joint disease characterized by progressive cartilage degradation and inflammation. In recent years, mesenchymal stem cells (MSCs) derived exosomes (MSCs-Exo) have attracted widespread attention for their potential role in modulating OA pathology. However, the unpredictable therapeutic effects of exosomes have been a significant barrier to their extensive clinical application. In this study, we investigated whether fucoidan-pretreated MSC-derived exosomes (F-MSCs-Exo) could better protect chondrocytes in osteoarthritic joints and elucidate its underlying mechanisms. In order to evaluate the role of F-MSCs-Exo in osteoarthritis, both in vitro and in vivo studies were conducted. MiRNA sequencing was employed to analyze MSCs-Exo and F-MSCs-Exo, enabling the identification of differentially expressed genes and the exploration of the underlying mechanisms behind the protective effects of F-MSCs-Exo in osteoarthritis. Compared to MSCs-Exo, F-MSCs-Exo demonstrated superior effectiveness in inhibiting inflammatory responses and extracellular matrix degradation in rat chondrocytes. Moreover, F-MSCs-Exo exhibited enhanced activation of autophagy in chondrocytes. MiRNA sequencing of both MSCs-Exo and F-MSCs-Exo revealed that miR-146b-5p emerged as a promising candidate mediator for the chondroprotective function of F-MSCs-Exo, with TRAF6 identified as its downstream target. In conclusion, our research results demonstrate that miR-146b-5p encapsulated in F-MSCs-Exo effectively inhibits TRAF6 activation, thereby suppressing inflammatory responses and extracellular matrix degradation, while promoting chondrocyte autophagy for the protection of osteoarthritic cartilage cells. Consequently, the development of a therapeutic approach combining fucoidan with MSC-derived exosomes provides a promising strategy for the clinical treatment of osteoarthritis.

Intravenous Autologous Bone Marrow-derived Mesenchymal Stromal Cells Delay Acute Respiratory Distress Syndrome in Swine

Rationale: Early post injury mitigation strategies in ARDS are in short supply. Treatments with allogeneic stromal cells are administered after ARDS develops, require specialized expertise and equipment, and to date have shown limited benefit. Objectives: Assess the efficacy of immediate post injury intravenous administration of autologous or allogeneic bone marrow-derived mesenchymal stromal cells (MSCs) for the treatment of acute respiratory distress syndrome (ARDS) due to smoke inhalation and burns. Methods: Yorkshire swine (n = 32, 44.3 ± 0.5 kg) underwent intravenous anesthesia, placement of lines, severe smoke inhalation, and 40% total body surface area flame burns, followed by 72 hours of around-the-clock ICU care. Mechanical ventilation, fluids, pressors, bronchoscopic cast removal, daily lung computed tomography scans, and arterial blood assays were performed. After injury and 24 and 48 hours later, animals were randomized to receive autologous concentrated bone marrow aspirate (n = 10; 3 × 106 white blood cells and a mean of 56.6 × 106 platelets per dose), allogeneic MSCs (n = 10; 6.1 × 106 MSCs per dose) harvested from healthy donor swine, or no treatment in injured control animals (n = 12). Measurements and Main Results: The intravenous administration of MSCs after injury and at 24 and 48 hours delayed the onset of ARDS in swine treated with autologous MSCs (48 ± 10 h) versus control animals (14 ± 2 h) (P = 0.004), reduced ARDS severity at 24 (P < 0.001) and 48 (P = 0.003) hours, and demonstrated visibly diminished consolidation on computed tomography (not significant). Mortality at 72 hours was 1 in 10 (10%) in the autologous group, 5 in 10 (50%) in the allogeneic group, and 6 in 12 (50%) in injured control animals (not significant). Both autologous and allogeneic MSCs suppressed systemic concentrations of TNF-α (tumor necrosis factor-α). Conclusions: The intravenous administration of three doses of freshly processed autologous bone marrow-derived MSCs delays ARDS development and reduces its severity in swine. Bedside retrieval and administration of autologous MSCs in swine is feasible and may be a viable injury mitigation strategy for ARDS.

Immunologic barriers in liver transplantation: a single-cell analysis of the role of mesenchymal stem cells

Background

This study aimed to analyze the biomarkers that may reliably indicate rejection or tolerance and the mechanism that underlie the induction and maintenance of liver transplantation (LT) tolerance related to immunosuppressant or mesenchymal stem cells (MSCs).

Methods

LT models of Lewis-Lewis and F344-Lewis rats were established. Lewis-Lewis rats model served as a control (Syn). F344-Lewis rats were treated with immunosuppressant alone (Allo+IS) or in combination with MSCs (Allo+IS+MSCs). Intrahepatic cell composition particularly immune cells was compared between the groups by single-cell sequencing. Analysis of subclusters, KEGG pathway analysis, and pseudotime trajectory analysis were performed to explore the potential immunoregulatory mechanisms of immunosuppressant alone or combined with MSCs.

Results

Immunosuppressants alone or combined with MSCs increases the liver tolerance, to a certain extent. Single-cell sequencing identified intrahepatic cell composition signature, including cell subpopulations of B cells, cholangiocytes, endothelial cells, erythrocytes, hepatic stellate cells, hepatocytes, mononuclear phagocytes, neutrophils, T cells, and plasmacytoid dendritic cells. Immunosuppressant particularly its combination with MSCs altered the landscape of intrahepatic cells in transplanted livers, as well as gene expression patterns in immune cells. MSCs may be included in the differentiation of T cells, classical monocytes, and non-classical monocytes.

Conclusion

These findings provided novel insights for better understanding the heterogeneity and biological functions of intrahepatic immune cells after LT treated by IS alone or in combination with MSCs. The identified markers of immune cells may serve as the immunotherapeutic targets for MSC treatment of liver transplant rejection.

Immunomodulation by mesenchymal stem cells during osteogenic differentiation: Clinical implications during bone regeneration

Critical bone defects resulting in delayed and non-union are a major concern in the field of orthopedics. Over the past decade, mesenchymal stem cells (MSCs) have become a promising frontier for bone repair and regeneration owing to their high expansion rate and osteogenic differentiation potential ex vivo. MSCs have also long been associated with their ability to modulate immune response in the recipients. These can even skew the immune response towards pro-inflammatory or anti-inflammatory type by sensing their local microenvironment. MSCs adopt anti-inflammatory phenotype at bone injury site and secrete various immunomodulatory factors such as IDO, NO, TGFβ1 and PGE-2 which have redundant role in osteoblast differentiation and bone formation. As such, several studies have also sought to decipher the immunomodulatory effects of osteogenically differentiated MSCs. The present review discusses the immunomodulatory status of MSCs during their osteogenic differentiation and summarizes few mechanisms that cause immunosuppression by osteogenically differentiated MSCs and its implication during bone healing.

Gingival mesenchymal stem cell therapy, immune cells, and immunoinflammatory application

MSC-based therapeutic strategies have proven to be incredibly effective. Robust self-renewal, multilineage differentiation, and potential for tissue regeneration and disease treatments are all features of MSCs isolated from oral tissue. Human exfoliated deciduous teeth, dental follicles, dental pulp, apical papilla SCs, and alveolar bone are the primary sources of oral MSC production. The early immunoinflammatory response is the first stage of the healing process. Oral MSCs can interact with various cells, such as immune cells, revealing potential immunomodulatory regulators. They also have strong differentiation and regeneration potential. Therefore, a ground-breaking strategy would be to research novel immunomodulatory approaches for treating disease and tissue regeneration that depend on the immunomodulatory activities of oral MSCs during tissue regeneration.

Integrin beta1 mediates the effect of telocytes on mesenchymal stem cell proliferation and migration in the treatment of acute lung injury

Co-transplantation of mesenchymal stem cells (MSCs) with telocytes (TCs) was found to have therapeutic effects, although the mechanism of intercellular communication is still unknown. Our current studies aim at exploring the potential molecular mechanisms of TCs interaction and communication with MSCs with a focus on integrin beta1 (ITGB1) in TCs. We found that the co-culture of MSCs with ITGB1-deleted TCs (TCITGB1-ko ) changed the proliferation, differentiation and growth dynamics ability of MSC in responses to LPS or PI3K inhibitor. Changes of MSC proliferation and apoptosis were accompanied with the dysregulation of cytokine mRNA expression in MSCs co-cultured with TCITGB1-ko during the exposure of PI3Kα/δ/β inhibitor, of which IL-1β, IL-6 and TNF-α increased, while IFN-γ, IL-4 and IL-10 decreased. The responses of PI3K p85, PI3K p110 and pAKT of MSCs co-cultured with TCITGB1-ko to LPS or PI3K inhibitor were opposite to those with ITGB1-presented TCs. The intraperitoneal injection of TCITGB1-ko , TCvector or MSCs alone, as well as the combination of MSCs with TCITGB1-ko or TCvector exhibited therapeutic effects on LPS-induced acute lung injury. Thus, our data indicate that telocyte ITGB1 contributes to the interaction and intercellular communication between MSCs and TCs, responsible for influencing other cell phenomes and functions.

Alleviation of doxorubicin-induced cardiotoxicity in rat by mesenchymal stem cells and olive leaf extract via MAPK/ TNF-α pathway: Preclinical, experimental and bioinformatics enrichment study

BACKGROUND

Toxic cardiomyopathies were a potentially fatal adverse effect of anthracycline therapy.

AIM

This study was conducted to demonstrate the pathogenetic, morphologic, and toxicologic effects of doxorubicin on the heart and to investigate how the MAPK /TNF-α pathway can be modulated to improve doxorubicin-Induced cardiac lesions using bone marrow-derived mesenchymal stem cells (BM-MSCs) and olive leaf extract (OLE).

METHODS

During the study, 40 adult male rats were used. Ten were used to donate MSCs, and the other 30 were split into 5 equal groups: Group I was the negative control, Group II obtained oral OLE, Group III obtained an intraperitoneal cumulative dose of DOX (12 mg/kg) in 6 equal doses of 2 mg/kg every 48 h for 12 days, Group IV obtained intraperitoneal DOX and oral OLE at the same time, and Group V obtained intraperitoneal DOX and BM-MSCs through the tail vein at the same time for 12 days. Four weeks after their last dose of DOX, the rats were euthanized. By checking the bioinformatic databases, a molecularly targeted path was selected. Then the histological, immunohistochemistry, and gene expression of ERK, JNK, NF-κB, IL-6, and TNF-α were done.

RESULTS

Myocardial immunohistochemistry revealed severe fibrosis, cell degeneration, increased vimentin, and decreased CD-31 expression in the DOX-treated group, along with a marked shift in morphometric measurements, a disordered ultrastructure, and overexpression of inflammatory genes (ERK, NF-κB, IL-6, and TNF-α), oxidative stress markers, and cardiac biomarkers. Both groups IV and V displayed reduced cardiac fibrosis or inflammation, restoration of the microstructure and ultrastructure of the myocardium, downregulation of inflammatory genes, markers of oxidative stress, and cardiac biomarkers, a notable decline in vimentin, and an uptick in CD-31 expression. In contrast to group IV, group V showed a considerable beneficial effect.

CONCLUSION

Both OLE and BM-MSCs showed an ameliorating effect in rat models of DOX-induced cardiotoxicity, with BM-MSCs showing a greater influence than OLE.

Mesenchymal stem cell implantation provides short-term clinical improvement and satisfactory cartilage restoration in patients with knee osteoarthritis but the evidence is limited: a systematic review performed by the early-osteoarthritis group of ESSKA-European knee associates section

PURPOSE

Implantation of mesenchymal stem cells (MSCs) is a potential cell-based modality for cartilage repair. Currently, its clinical use largely surrounds focal cartilage defect repair and intra-articular injections in knee osteoarthritis. The MSCs' implantation efficacy as a treatment option for osteoarthritis remains contentious. This systematic review aims to evaluate studies that focused on MSCs implantation in patients with knee OA to provide a summary of this treatment option outcomes.

METHODS

A systematic search was performed in PubMed (Medline), Scopus, Cinahl, and the Cochrane Library. Original studies investigating outcomes of MSCs implantations in patients with knee OA were included. Data on clinical outcomes using subjective scores, radiological outcomes, and second-look arthroscopy gradings were extracted.

RESULTS

Nine studies were included in this review. In all included studies, clinical outcome scores revealed significantly improved functionality and better postoperative pain scores at 2-3 years follow-up. Improved cartilage volume and quality at the lesion site was observed in five studies that included a postoperative magnetic resonance imaging assessment and studies that performed second-look arthroscopy. No major complications or tumorigenesis occurred. Outcomes were consistent in both single MSCs implantation and concurrent HTO with MSCs implantation in cases with excessive varus deformity.

CONCLUSION

According to the available literature, MSCs implantation in patients with mild to moderate knee osteoarthritis is safe and provides short-term clinical improvement and satisfactory cartilage restoration, either as a standalone procedure or combined with HTO in cases with axial deformity. However, the evidence is limited due to the high heterogeneity among studies and the insufficient number of studies including a control group and mid-term outcomes.

LEVEL OF EVIDENCE

IV.