The Current Status of Mesenchymal Stromal Cells: Controversies, Unresolved Issues and Some Promising Solutions to Improve Their Therapeutic Efficacy

Regulation and functional importance of human periodontal ligament mesenchymal stromal cells with various rates of CD146+ cells

Introduction

Mesenchymal stromal cells (MSCs) with high expression of CD146 have superior properties for tissue regeneration. However, high variability in the rate of CD146+ cells among donors is observed. In this study, the possible reasons behind this variability in human periodontal ligament MSCs (hPDL-MSCs) were explored.

Methods

hPDL-MSCs were isolated from 22 different donors, and rates of CD146+ cells were analyzed by flow cytometry. Furthermore, populations with various rates of CD146+ cells were isolated with magnetic separation. The dependency of cell proliferation, viability, cell cycle, and osteogenic differentiation on the rates of CD146+ cells was investigated. Besides, the effects of various factors, like cell density, confluence, and inflammatory environment on the CD146+ rate and expression were analyzed.

Results

The rate of CD146+ cells exhibited high variability between donors, with the percentage of CD146+ cells ranging from 3% to 67%. Higher percentage of CD146+ cells was associated with higher proliferation, presumably due to the higher percentage of cells in the S-phase, and higher osteogenic differentiation potential. Prolonged cell confluence and higher cell seeding density led to the decline in the rate of CD146+ cells. The surface rate of CD146 in hPDL-MSCs was stimulated by the treatment with interleukin-1β and tumor necrosis factor-α, and inhibited by the treatment with interferon-γ.

Conclusion

These results suggest that hPDL-MSCs with high rate of CD146+ cells are a promising subpopulation for enhancing the effectiveness of MSC-based regenerative therapies, however the rate of CD146 is affected by various factors, which must be considered for cell propagation and their potential application in vivo.

Steps towards the clinical application of endometrial and menstrual fluid mesenchymal stem cells for the treatment of gynecological disorders

INTRODUCTION

The human endometrium is a highly regenerative tissue that contains mesenchymal stem/stromal cells (MSCs). These MSCs are sourced via office-based biopsies and menstrual fluid, providing a less invasive and readily available option for cell-based therapies. This review provides an update on endometrial-derived MSCs as a treatment option for gynecological diseases.

AREAS COVERED

This narrative review covers the characterization and therapeutic mechanisms of endometrium biopsy-derived MSCs (eMSCs) and menstrual fluid-derived mesenchymal stromal cells (MenSCs), highlighting similarities and differences. It also covers studies of their application in preclinical animal models and in clinical trials as potential cell-based therapies for gynecological diseases.

EXPERT OPINION

eMSCs and MenSCs from a homologous tissue source have the potential to promote regenerative activity as a treatment for gynecological diseases. Both eMSCs and MenSCs demonstrate therapeutic benefits through their paracrine activity in tissue regeneration, immunomodulation, angiogenesis, and mitigating fibrosis. Further research is essential to establish standardized isolation and characterization protocols, particularly for heterogeneous MenSCs, and to fully understand their mechanisms of action. Implementing SUSD2 magnetic bead sorting for purifying eMSCs from endometrial tissues and menstrual fluid is crucial for their use in future cell-based therapies. Optimization of production, storage, and delivery methods will maximize their therapeutic effectiveness.

Improving the therapeutic profile of MSCs: Cytokine priming reduces donor-dependent heterogeneity and enhances their immunomodulatory capacity

Introduction

MSCs exhibit regenerative, anti-inflammatory and immunomodulatory properties due to the large amount of cytokines, chemokines and growth factors they secrete. MSCs have been extensively evaluated in clinical trials, however, in some cases their therapeutic effects are variable. Therefore, strategies to improve their therapeutic potential, such as preconditioning with proinflammatory factors, have been proposed. Several priming approaches have provided non-conclusive results, and the duration of priming effects on MSC properties or their response to a second inflammatory stimulus have not been fully addressed.

Methods

We have investigated the impact of triple cytokine priming in MSCs on their characterization and viability, their transcriptomic profile, the functionality of innate and acquired immune cells, as well as the maintenance of the response to priming over time, their subsequent responsiveness to a second inflammatory stimulus.

Results

Priming MSCs with proinflammatory cytokines (CK-MSCs) do not modify the differentiation capacity of MSCs, nor their immunophenotype and viability. Moreover, cytokine priming enhances the anti-inflammatory and immunomodulatory properties of MSCs against NK and dendritic cells, while maintaining the same T cell immunomodulatory capacity as unstimulated MSCs. Thus, they decrease T-lymphocytes and NK cell proliferation, inhibit the differentiation and allostimulatory capacity of dendritic cells and promote the differentiation of monocytes with an immunosuppressive profile. In addition, we have shown for the first time that proinflammatory priming reduces the variability between different donors and MSC origins. Finally, the effect on CK-MSC is maintained over time and even after a secondary inflammatory stimulus.

Conclusions

Cytokine-priming improves the therapeutic potential of MSCs and reduces inter-donor variability.

Automated Manufacturing Processes and Platforms for Large-scale Production of Clinical-grade Mesenchymal Stem/ Stromal Cells

Mesenchymal stem/stromal cells (MSCs) hold immense potential for regenerative medicine due to their remarkable regenerative and immunomodulatory properties. However, their therapeutic application requires large-scale production under stringent regulatory standards and Good Manufacturing Practice (GMP) guidelines, presenting significant challenges. This review comprehensively evaluates automated manufacturing processes and platforms for the scalable production of clinical-grade MSCs. Various large-scale culture vessels, including multilayer flasks and bioreactors, are analyzed for their efficacy in MSCs expansion. Furthermore, automated MSCs production platforms, such as Quantum® Cell Expansion System, CliniMACS Prodigy®, NANT001/ XL, CellQualia™, Cocoon® Platform, and Xuri™ Cell Expansion System W25 are reviewed and compared as well. We also underscore the importance of optimizing culture media specifically emphasizing the shift from fetal bovine serum to humanized or serum-free alternatives to meet GMP standards. Moreover, advances in alternative cryopreservation methods and controlled-rate freezing systems, that offer promising improvements in MSCs preservation, are discussed as well. In conclusion, advancing automated manufacturing processes and platforms is essential for realizing the full potential of MSCs-based regenerative medicine and accomplishing the increasing demand for cell-based therapies. Collaborative initiatives involving industry, academia, and regulatory bodies are emphasized to accelerate the translation of MSCs-based therapies into clinical practice.

Highly precise strategy of polygalacturonic acid microcarriers functionalized with zwitterions and specific peptides for MSC screening

Microcarriers for large-scale cell culture have a broader prospect in cell screening compared with the traditional high cost, low efficiency, and cell damaging methods. However, the equal biological affinity to cells has hindered its application. Therefore, based on the antifouling strategy of zwitterionic polymer, we developed a cell-specific microcarrier (CSMC) for shielding non-target cells and capturing mesenchymal stem cells (MSCs), which has characteristics of high biocompatibility, low background noise and high precision. Briefly, [2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide and glycidyl methacrylate were grafted onto polygalacturonic acid, respectively. The former built a hydration layer through solvation to provide an excellent antifouling surface, while the latter provided active sites for the click reaction with sulfhydryl-modified cell-specific peptides, resulting in rapid immobilization of peptides. This method is applicable to the vast majority of polysaccharide materials. The accurate capture ratio of MSCs by CSMC in a mixed multicellular environment is >95 % and the proliferation rate of MSCs on microcarriers is satisfactory. In summary, this grafting strategy of bioactive components lays a foundation for the application of polysaccharide materials in the biomedical field, and the specific adhesive microcarriers also open up new ideas for the development of stem cell screening as well.

Mesenchymal stromal cell therapies for traumatic neurological injuries

Improved treatment options are urgently needed for neurological injuries resulting from trauma or iatrogenic events causing long-term disabilities that severely impact patients' quality of life. In vitro and animal studies have provided promising proof-of-concept examples of regenerative therapies using mesenchymal stromal cells (MSC) for a wide range of pathological conditions. Over the previous decade, various MSC-based therapies have been investigated in clinical trials to treat traumatic neurological injuries. However, while the safety and feasibility of MSC treatments has been established, the patient outcomes in these studies have not demonstrated significant success in the translation of MSC regenerative therapy for the treatment of human brain and spinal cord injuries. Herein, we have reviewed the literature and ongoing registered trials on the application of MSC for the treatment of traumatic brain injury, traumatic spinal cord injury, and peripheral nerve injury. We have focused on the shortcomings and technological hurdles that must be overcome to further advance clinical research to phase 3 trials, and we discuss recent advancements that represent potential solutions to these obstacles to progress.

Renal remodeling by CXCL10-CXCR3 axis-recruited mesenchymal stem cells and subsequent IL4I1 secretion in lupus nephritis

Human umbilical cord mesenchymal stem cells (hUC-MSCs) have shown potential as a therapeutic option for lupus nephritis (LN), particularly in patients refractory to conventional treatments. Despite extensive translational research on MSCs, the precise mechanisms by which MSCs migrate to the kidney and restore renal function remain incompletely understood. Here, we aim to clarify the spatiotemporal characteristics of hUC-MSC migration into LN kidneys and their interactions with host cells in microenvironment. This study elucidates that the migration of hUC-MSCs to the LN kidney is driven by elevated levels of CXCL10, predominantly produced by glomerular vascular endothelial cells through the IFN-γ/IRF1-KPNA4 pathway. Interestingly, the blockade of CXCL10-CXCR3 axis impedes the migration of hUC-MSCs to LN kidney and negatively impacts therapeutic outcomes. Single cell-RNA sequencing analysis underscores the importance of this axis in mediating the regulatory effects of hUC-MSCs on the renal immune environment. Furthermore, hUC-MSCs have been observed to induce and secrete interleukin 4 inducible gene 1 (IL4I1) in response to the microenvironment of LN kidney, thereby suppressing Th1 cells. Genetically ablating IL4I1 in hUC-MSCs abolishes their therapeutic effects and prevents the inhibition of CXCR3+ Th1 cell infiltration into LN kidneys. This study provides valuable insights into the significant involvement of CXCL10-CXCR3 axis in hUC-MSC migration to the LN kidneys and the subsequent remodeling of renal immune microenvironment. Regulating the CXCL10-CXCR3 axis and IL4I1 secretion may be developed as a novel therapeutic strategy to improve treatment outcomes of LN.

Behavioral dynamics of medicinal signaling cells from porcine bone marrow in long-term culture

Medicinal signaling cells (MSC) hold promise for regenerative medicine due to their ability to repair damaged tissues. However, their effectiveness can be affected by how long they are cultured in the lab. This study investigated how passage number influences key properties for regenerative medicine of pig bone marrow MSC. The medicinal signiling cells derived from pig bone marrow (BM-MSC) were cultured in D-MEM High Glucose supplemented with 15% foetal bovine serum until the 25th passage and assessed their growth, viability, ability to differentiate into different cell types (plasticity), and cell cycle activity. Our findings showed that while the cells remained viable until the 25th passage, their ability to grow and differentiate declined after the 5th passage. Additionally, cells in later passages spent more time in a resting phase, suggesting reduced activity. In conclusion, the number of passages is a critical factor for maintaining ideal MSC characteristics. From the 9th passage BM-MSC exhibit decline in proliferation, differentiation potential, and cell cycle activity. Given this, it is possible to suggest that the use of 5th passage cells is the most suitable for therapeutic applications.

Mesenchymal Stem Cells and Tissue Bioengineering Applications in Sheep as Ideal Model

The most common technologies in tissue engineering include growth factor therapies; metal implants, such as titanium; 3D bioprinting; nanoimprinting for ceramic/polymer scaffolds; and cell therapies, such as mesenchymal stem cells (MSCs). Cell therapy is a promising alternative to organ grafts and transplants in the treatment of numerous musculoskeletal diseases. MSCs have increasingly been used in generative medicine due to their specialized self-renewal, immunomodulation, multiplication, and differentiation properties. To further expand the potential of these cells in tissue repair, significant efforts are currently dedicated to the production of biomaterials with desirable short- and long-term biophysical properties that can aid the differentiation and expansion of MSCs. Biomaterials support MSC differentiation by modulating their characteristics, such as composition, mechanical properties, porosity, and topography. This review aimed to describe recent MSC approaches, including those associated with biomaterials, from experimental, clinical, and preclinical studies with sheep models.

The lack of EphB3 receptor prevents bone loss in mouse models of osteoporosis

Bone homeostasis is a complex process in which some Eph kinase receptors and their ephrin ligands appear to be involved. In the present study, we address this issue by examining, both in vitro and in vivo, the role of EphB2 and EphB3 in mesenchymal stromal/stem cell (MSC) differentiation into bone tissue. This was first evaluated by quantitative reverse transcription PCR (RT-qPCR) and histological staining in MSCs cultured in specific mediums revealing that although EphB2-/- MSCs mainly expressed pro-adipogenic transcription factors, EphB3-/- MSCs showed abundant osteogenic transcripts, such as Runx2, Msx2, and Sp7. To clarify the underlying molecular mechanisms, we found that the lack of EphB3 signaling alters the genetic profile of differentiating MSCs, reducing the expression of many inhibitory molecules and antagonists of the BMP signaling pathway, and increasing Bmp7 expression, a robust bone inductor. Then, to confirm the osteogenic role of EphB3 in vivo, we studied the condition of 2 mouse models of induced bone loss (ovariectomy or long-term glucocorticoid treatment). Interestingly, in both models, both WT and EphB2-/- mice equally developed the disease but EphB3-/- mice did not exhibit the typical bone loss, nor an increase in urine Ca2+ or blood serum CTX-1. This phenotype in EphB3-KO mice could be due to their significantly higher proportions of osteoprogenitor cells and preosteoblasts, and their lower number of osteoclasts, as compared with WT and EphB2-KO mice. Thus, we conclude that EphB3 acts as a negative regulator of the osteogenic differentiation, and its absence prevents bone loss in mice subjected to ovariectomy or dexamethasone treatment.

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.

Challenges of therapeutic applications and regenerative capacities of urine based stem cells in oral, and maxillofacial reconstruction

Urine-derived stem cells (USCs) have gained the attention of researchers in the biomedical field in the past few years . Regarding the several varieties of cells that have been used for this purpose, USCs have demonstrated mesenchymal stem cell-like properties, such as differentiation and immunomodulation. Furthermore, they could be differentiated into several lineages. This is very interesting for regenerative techniques based on cell therapy. This review will embark on describing their separation, and profiling. We will specifically describe the USCs characteristics, in addition to their differentiation potential. Then, we will introduce and explore the primary uses of USCs. These involve thier utilization as a platform to produce stem cells, however, we shall concentrate on the utilization of USCs for therapeutic, and regenerative orofacial applications, providing an in-depth evaluation of this purpose. The final portion will address the limitations and challenges of their implementation in regenerative dentistry.

Bushen Huoxue recipe ameliorates ovarian function via promoting BMSCs proliferation and homing to ovaries in POI mice

BACKGROUND

Premature ovarian insufficiency (POI) is a tricky puzzle in the field of female reproductive medicine. Bushen Huoxue recipe (BHR), a traditional Chinese medicine compound based on the combination of kidney-tonifying and blood-activating functions, has shown excellent efficacy in improving female irregular menstruation, POI, and infertility. However, the potential mechanism of BHR in POI treatment has not yet been elucidated. Bone marrow mesenchymal stem cells (BMSCs), a type of pluripotent stem cells, have received increasing attention for their significant role in improving ovarian function and restoring fertility in women with POI.

PURPOSE

This study aimed to evaluate the therapeutic effect of BHR in POI mice and explore its potential mechanism.

METHODS

A POI mouse model was established with a single intraperitoneal injection of 120 mg/kg cyclophosphamide (CTX). Distilled water, BHR, or dehydroepiandrosterone was administered via gavage for 28 consecutive days. The effect of BHR on ovarian function in POI mice was evaluated by assessing the estrous cycle, ovarian morphology, follicular development, hormone levels, and angiogenesis. The proportion of BMSCs in bone marrow, peripheral blood, and ovary was analyzed via flow cytometry, and the level of molecules mediating migration and homing in ovary was measured. Cell viability assays, scratch healing assays and transwell migration assays were performed to explore the effect of BHR on BMSCs proliferation and migration in vitro, and its potential mechanism was explored.

RESULTS

BHR significantly ameliorated estrous cycle disorders, hormone disorders, ovarian morphology, ovarian microvascular formation, and ovarian reserve in POI mice. Meanwhile, the number of BMSCs number in the bone marrow, peripheral blood, and ovary was apparently increased. Of note, BHR increased the level of hepatocyte growth factor (HGF)/cellular mesenchymal epithelial transition factor (cMET) and stromal cell-derived factor-1(SDF-1)/CXC chemokine receptor 4 (CXCR4) in the ovaries of POI mice. Moreover, BHR treatment promoted BMSCs proliferation and migration in vitro, with a significant increase in the level of proliferating cell nuclear antigen, cMET, and CXCR4.

CONCLUSIONS

BHR effectively restored ovarian reserve, ovarian function, and ovarian angiogenesis in CTX-induced POI mice. In addition, BHR promoted BMSCs proliferation, migration, and homing to the ovary, which was mediated by the SDF-1/CXCR4 and HGF/cMET signaling axis. Finally, the amelioration of ovarian reserve and ovarian function in CTX-induced POI mice by BHR may be related to its promotion of endogenous BMSCs proliferation and homing.

Precision Nanomedicine with Bio-Inspired Nanosystems: Recent Trends and Challenges in Mesenchymal Stem Cells Membrane-Coated Bioengineered Nanocarriers in Targeted Nanotherapeutics

In the recent past, the formulation and development of nanocarriers has been elaborated into the broader fields and opened various avenues in their preclinical and clinical applications. In particular, the cellular membrane-based nanoformulations have been formulated to surpass and surmount the limitations and restrictions associated with naïve or free forms of therapeutic compounds and circumvent various physicochemical and immunological barriers including but not limited to systemic barriers, microenvironmental roadblocks, and other cellular or subcellular hinderances-which are quite heterogeneous throughout the diseases and patient cohorts. These limitations in drug delivery have been overcome through mesenchymal cells membrane-based precision therapeutics, where these interventions have led to the significant enhancements in therapeutic efficacies. However, the formulation and development of nanocarriers still focuses on optimization of drug delivery paradigms with a one-size-fits-all resolutions. As mesenchymal stem cell membrane-based nanocarriers have been engineered in highly diversified fashions, these are being optimized for delivering the drug payloads in more and better personalized modes, entering the arena of precision as well as personalized nanomedicine. In this Review, we have included some of the advanced nanocarriers which have been designed and been utilized in both the non-personalized as well as precision applicability which can be employed for the improvements in precision nanotherapeutics. In the present report, authors have focused on various other aspects of the advancements in stem cells membrane-based nanoparticle conceptions which can surmount several roadblocks and barriers in drug delivery and nanomedicine. It has been suggested that well-informed designing of these nanocarriers will lead to appreciable improvements in the therapeutic efficacy in therapeutic payload delivery applications. These approaches will also enable the tailored and customized designs of MSC-based nanocarriers for personalized therapeutic applications, and finally amending the patient outcomes.

Bioengineered Mesenchymal Stem/Stromal Cells in Anti-Cancer Therapy: Current Trends and Future Prospects

Mesenchymal stem/stromal cells (MSCs) are one of the most widely used cell types in advanced therapies due to their therapeutic potential in the regulation of tissue repair and homeostasis, and immune modulation. However, their use in cancer therapy is controversial: they can inhibit cancer cell proliferation, but also potentially promote tumour growth by supporting angiogenesis, modulation of the immune milieu and increasing cancer stem cell invasiveness. This opposite behaviour highlights the need for careful and nuanced use of MSCs in cancer treatment. To optimize their anti-cancer effects, diverse strategies have bioengineered MSCs to enhance their tumour targeting and therapeutic properties or to deliver anti-cancer drugs. In this review, we highlight the advanced uses of MSCs in cancer therapy, particularly as carriers of targeted treatments due to their natural tumour-homing capabilities. We also discuss the potential of MSC-derived extracellular vesicles to improve the efficiency of drug or molecule delivery to cancer cells. Ongoing clinical trials are evaluating the therapeutic potential of these cells and setting the stage for future advances in MSC-based cancer treatment. It is critical to identify the broad and potent applications of bioengineered MSCs in solid tumour targeting and anti-cancer agent delivery to position them as effective therapeutics in the evolving field of cancer therapy.

Effects of mesenchymal stem cells versus curcumin on sonic hedgehog signaling in experimental model of Hepatocellular Carcinoma

BACKGROUND

Sonic Hedgehog (SHH) is a fundamental signaling pathway that controls tissue reconstruction, stem cell biology, and differentiation and has a role in gut tissue homeostasis and development. Dysregulation of SHH leads to the development of HCC.

METHODS, AND RESULTS

The present study was conducted to compare the effects of mesenchymal stem cells (MSCs) and curcumin on SHH molecular targets in an experimental model of HCC in rats. One hundred rats were divided equally into the following groups: control group, HCC group, HCC group received MSCs, HCC group received curcumin, and HCC group received MSCs and curcumin. Histopathological examinations were performed, and gene expression of SHH signaling target genes (SHH, PTCH1, SMOH, and GLI1) was assessed by real-time PCR in rat liver tissue. Results showed that SHH target genes were significantly upregulated in HCC-untreated rat groups and in MSC-treated groups, with no significant difference between them. Administration of curcumin with or without combined administration of MSCs led to a significant down-regulation of SHH target genes, with no significant differences between both groups. As regards the histopathological examination of liver tissues, both curcumin and MSCs, either through separate use or their combined use, led to a significant restoration of normal liver pathology.

CONCLUSIONS

In conclusion, SHH signaling is upregulated in the HCC experimental model. MSCs do not inhibit the upregulated SHH target genes in HCC. Curcumin use with or without MSCs administration led to a significant down-regulation of SHH signaling in HCC and a significant restoration of normal liver pathology.

Gut bacteriome and mood disorders in women with PCOS

STUDY QUESTION

How does the gut bacteriome differ based on mood disorders (MDs) in women with polycystic ovary syndrome (PCOS), and how can the gut bacteriome contribute to the associations between these two conditions?

SUMMARY ANSWER

Women with PCOS who also have MDs exhibited a distinct gut bacteriome with reduced alpha diversity and a significantly lower abundance of Butyricicoccus compared to women with PCOS but without MDs.

WHAT IS KNOWN ALREADY

Women with PCOS have a 4- to 5-fold higher risk of having MDs compared to women without PCOS. The gut bacteriome has been suggested to influence the pathophysiology of both PCOS and MDs.

STUDY DESIGN, SIZE, DURATION

This population-based cohort study was derived from the Northern Finland Birth Cohort 1966 (NFBC1966), which includes all women born in Northern Finland in 1966. Women with PCOS who donated a stool sample at age 46 years (n = 102) and two BMI-matched controls for each case (n = 205), who also responded properly to the MD criteria scales, were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 102 women with PCOS and 205 age- and BMI-matched women without PCOS were included. Based on the validated MD criteria, the subjects were categorized into MD or no-MD groups, resulting in the following subgroups: PCOS no-MD (n = 84), PCOS MD (n = 18), control no-MD (n = 180), and control MD (n = 25). Clinical characteristics were assessed at age 31 years and age 46 years, and stool samples were collected from the women at age 46 years, followed by the gut bacteriome analysis using 16 s rRNA sequencing. Alpha diversity was assessed using observed features and Shannon's index, with a focus on genera, and beta diversity was characterized using principal components analysis (PCA) with Bray-Curtis Dissimilarity at the genus level. Associations between the gut bacteriome and PCOS-related clinical features were explored by Spearman's correlation coefficient. A P-value for multiple testing was adjusted with the Benjamini-Hochberg false discovery rate (FDR) method.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed changes in the gut bacteriome associated with MDs, irrespective of whether the women also had PCOS. Similarly, PCOS MD cases showed a lower alpha diversity (Observed feature, PCOS no-MD, median 272; PCOS MD, median 208, FDR = 0.01; Shannon, PCOS no-MD, median 5.95; PCOS MD, median 5.57, FDR = 0.01) but also a lower abundance of Butyricicoccus (log-fold changeAnalysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC)=-0.90, FDRANCOM-BC=0.04) compared to PCOS no-MD cases. In contrast, in the controls, the gut bacteriome did not differ based on MDs. Furthermore, in the PCOS group, Sutterella showed positive correlations with PCOS-related clinical parameters linked to obesity (BMI, r2=0.31, FDR = 0.01; waist circumference, r2=0.29, FDR = 0.02), glucose metabolism (fasting glucose, r2=0.46, FDR < 0.001; fasting insulin, r2=0.24, FDR = 0.05), and gut barrier integrity (zonulin, r2=0.25, FDR = 0.03).

LIMITATIONS, REASONS FOR CAUTION

Although this was the first study to assess the link between the gut bacteriome and MDs in PCOS and included the largest PCOS dataset for the gut microbiome analysis, the number of subjects stratified by the presence of MDs was limited when contrasted with previous studies that focused on MDs in a non-selected population.

WIDER IMPLICATIONS OF THE FINDINGS

The main finding is that gut bacteriome is associated with MDs irrespective of the PCOS status, but PCOS may also modulate further the connection between the gut bacteriome and MDs.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement (MATER, No. 813707), the Academy of Finland (project grants 315921, 321763, 336449), the Sigrid Jusélius Foundation, Novo Nordisk Foundation (NNF21OC0070372), grant numbers PID2021-12728OB-100 (Endo-Map) and CNS2022-135999 (ROSY) funded by MCIN/AEI/10.13039/501100011033 and ERFD A Way of Making Europe. The study was also supported by EU QLG1-CT-2000-01643 (EUROBLCS) (E51560), NorFA (731, 20056, 30167), USA/NIH 2000 G DF682 (50945), the Estonian Research Council (PRG1076, PRG1414), EMBO Installation (3573), and Horizon 2020 Innovation Grant (ERIN, No. EU952516). The funders did not participate in any process of the study. We have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Hollow fiber bioreactor allows sustained production of immortalized mesenchymal stromal cell-derived extracellular vesicles

Aim: Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) have been reported to hold great potential as cell-free therapies due to their low immunogenicity and minimal toxicity. However, the large doses of MSC-EVs that are required for their clinical application highlight the urgency of finding a large-scale system for MSC-EV manufacture. In this study, we aimed to set up a hollow fiber bioreactor system for the continuous homogenous production of functional and high-quality MSC-EVs. Methods: MSC lines from two donors were immortalized (iMSC) and inoculated into hollow fiber bioreactors. Throughout 4 weeks, conditioned medium was daily harvested. iMSC-EVs were purified and characterized for content, immunophenotype, size, and functionality and compared to 2D cultured iMSC. Results: The iMSC inoculated into the bioreactor remained viable during the whole culture period, and they maintained their MSC phenotype at the end of EV production. Our results showed that the bioreactor system allows to obtain 3D-cultured iMSC-derived EVs (3D-EVs) that are comparable to flask (2D)-cultured iMSC-derived EVs (2D-EVs) in terms of protein and lipid content, size, and phenotype. We also confirm that 3D-derived EVs exhibit comparable functionality to 2D-EVs, showing pro-angiogenic potential in a dose-dependent manner. Conclusions: These findings suggest that setting up a hollow fiber bioreactor system inoculating immortalized MSC lines facilitates the large-scale, functional, and high-quality production of iMSC-EVs. Our results emphasize the great potential of this production methodology to standardize EV production in the pursuit of clinical applications.

Optimizing cryopreservation conditions for use of fucosylated human mesenchymal stromal cells in anti-inflammatory/immunomodulatory therapeutics

Mesenchymal stem/stromal cells (MSCs) are being increasingly used in cell-based therapies due to their broad anti-inflammatory and immunomodulatory properties. Intravascularly-administered MSCs do not efficiently migrate to sites of inflammation/immunopathology, but this shortfall has been overcome by cell surface enzymatic fucosylation to engender expression of the potent E-selectin ligand HCELL. In applications of cell-based therapies, cryopreservation enables stability in both storage and transport of the produced cells from the manufacturing facility to the point of care. However, it has been reported that cryopreservation and thawing dampens their immunomodulatory/anti-inflammatory activity even after a reactivation/reconditioning step. To address this issue, we employed a variety of methods to cryopreserve and thaw fucosylated human MSCs derived from either bone marrow or adipose tissue sources. We then evaluated their immunosuppressive properties, cell viability, morphology, proliferation kinetics, immunophenotype, senescence, and osteogenic and adipogenic differentiation. Our studies provide new insights into the immunobiology of cryopreserved and thawed MSCs and offer a readily applicable approach to optimize the use of fucosylated human allogeneic MSCs as immunomodulatory/anti-inflammatory therapeutics.

Interplay between mesenchymal stromal cells and the immune system after transplantation: implications for advanced cell therapy in the retina

Advanced mesenchymal stromal cell-based therapies for neurodegenerative diseases are widely investigated in preclinical models. Mesenchymal stromal cells are well positioned as therapeutics because they address the underlying mechanisms of neurodegeneration, namely trophic factor deprivation and neuroinflammation. Most studies have focused on the beneficial effects of mesenchymal stromal cell transplantation on neuronal survival or functional improvement. However, little attention has been paid to the interaction between mesenchymal stromal cells and the host immune system due to the immunomodulatory properties of mesenchymal stromal cells and the long-held belief of the immunoprivileged status of the central nervous system. Here, we review the crosstalk between mesenchymal stromal cells and the immune system in general and in the context of the central nervous system, focusing on recent work in the retina and the importance of the type of transplantation.

The immunogenic profile and immunomodulatory function of mesenchymal stromal / stem cells in the presence of Ptychotis verticillata

Mesenchymal stromal/stem cells (MSCs) are considered to be a promising immunotherapeutic tool due to their easy accessibility, culture expansion possibilities, safety profile, and immunomodulatory properties. Although several studies have demonstrated the therapeutic effects of MSCs, their efficacy needs to be improved while also preserving their safety. It has been suggested that cell homeostasis may be particularly sensitive to plant extracts. The impact of natural compounds on immunity is thus a fascinating and growing field. Ptychotis verticillata and its bioactive molecules, carvacrol and thymol, are potential candidates for improving MSC therapeutic effects. They can be used as immunotherapeutic agents to regulate MSC functions and behavior during immunomodulation. Depending on their concentrations and incubation time, these compounds strengthened the immunomodulatory functions of MSCs while maintaining their immune-evasive profile. Incubating MSCs with carvacrol and thymol does not alter their hypoimmunogenicity, as no induction of the allogeneic immune response was observed. MSCs also showed enhanced abilities to reduce the proliferation of activated T cells. Thus, MSCs are immunologically responsive to bioactive molecules derived from PV. The bioactivity may depend on the whole phyto-complex of the oil. These findings may contribute to the development of safe and efficient immunotherapeutic MSCs by using medicinal plant-derived active molecules.

Mesenchymal stromal cells (MSCs) as a therapeutic agent of inflammatory disease and infectious COVID-19 virus: live or dead mesenchymal?

The COVID-19 infection is a worldwide disease that causes numerous immune-inflammatory disorders, tissue damage, and lung dysfunction. COVID-19 vaccines, including those from Pfizer, AstraZeneca, and Sinopharm, are available globally as effective interventions for combating the disease. The severity of COVID-19 can be most effectively reduced by mesenchymal stromal cells (MSCs) because they possess anti-inflammatory activity and can reverse lung dysfunction. MSCs can be harvested from various sources, such as adipose tissue, bone marrow, peripheral blood, inner organs, and neonatal tissues. The regulation of inflammatory cytokines is crucial in inhibiting inflammatory diseases and promoting the presence of anti-inflammatory cytokines for infectious diseases. MSCs have been employed as therapeutic agents for tissue damage, diabetes, autoimmune diseases, and COVID-19 patients. Our research aimed to determine whether live or dead MSCs are more suitable for the treatment of COVID-19 patients. Our findings concluded that dead MSCs, when directly administered to the patient, offer advantages over viable MSCs due to their extended presence and higher levels of immune regulation, such as T-reg, B-reg, and IL-10, compared to live MSCs. Additionally, dead and apoptotic MSCs are likely to be more readily captured by monocytes and macrophages, prolonging their presence compared to live MSCs.

The nuclei of human adult stem cells can move within the cell and generate cellular protrusions to contact other cells

BACKGROUND

The neuronal transdifferentiation of adult bone marrow cells (BMCs) is still considered an artifact based on an alternative explanation of experimental results supporting this phenomenon obtained over decades. However, recent studies have shown that following neural induction, BMCs enter an intermediate cellular state before adopting neural-like morphologies by active neurite extension and that binucleated BMCs can be formed independent of any cell fusion events. These findings provide evidence to reject the idea that BMC neural transdifferentiation is merely an experimental artifact. Therefore, understanding the intermediate states that cells pass through during transdifferentiation is crucial given their potential application in regenerative medicine and disease modelling.

METHODS

In this study, we examined the functional significance of the variety of morphologies and positioning that cell nuclei of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) can adopt during neural-like differentiation using live-cell nuclear fluorescence labelling, time-lapse microscopy, and confocal microscopy analysis.

RESULTS

Here, we showed that after neural induction, hBM-MSCs enter an intermediate cellular state in which the nuclei are able to move within the cells, switching shapes and positioning and even generating cellular protrusions as they attempt to contact the cells around them. These findings suggest that changes in nuclear positioning occur because human cell nuclei somehow sense their environment. In addition, we showed the process of direct interactions between cell nuclei, which opens the possibility of a new level of intercellular interaction.

CONCLUSIONS

The present study advances the understanding of the intermediate stage through which hBM-MSCs pass during neural transdifferentiation, which may be crucial to understanding the mechanisms of these cell conversion processes and eventually harness them for use in regenerative medicine. Importantly, our study provides for the first time evidence that the nuclei of hBM-MSC-derived intermediate cells somehow sense their environment, generating cellular protrusions to contact other cells. In summary, human mesenchymal stromal cells could not only help to increase our understanding of the mechanisms underlying cellular plasticity but also facilitate the exact significance of nuclear positioning in cellular function and in tissue physiology.

Induction of mesenchymal stem cell (MSC) differentiation from iPS cells using MSC medium

Mesenchymal stem cells (MSCs) and induced pluripotent stem (iPS) cells have great potential as cell sources for tissue engineering and regenerative medicine. This study aimed to investigate whether iPS cells can be differentiated into MSCs using MSCGM, a commercially available MSC culture system. The cells were characterized by flow cytometry, immunostaining, and gene expression analyses. We also examined their potential to differentiate into osteoblasts and chondrocytes. Our results showed that iPS cells cultured in MSCGM (iPS-MSCGM) exhibited a fibroblast-like morphology and expressed CD73 and CD90 genes, as well as positive markers for CD73, CD90, and CD105. Moreover, iPS-MSCGM cells demonstrated the ability to differentiate into osteoblasts and chondrocytes in vitro. This study demonstrates a new and simple method for inducing the differentiation of iPS cells to MSCs using MSCGM.

Fucoxanthin Enhances the Antifibrotic Potential of Placenta-derived Mesenchymal Stem Cells in a CCl4-induced Mouse Model of Liver

BACKGROUND

The effectiveness of fucoxanthin (Fx) in liver diseases has been reported due to its anti-inflammatory and antifibrotic effects. Mesenchymal stem cells (MSCs)-based therapy has also been proposed as a promising strategy for liver fibrosis treatment. Recent studies have shown that the co-administration of MSCs and drugs demonstrates a pronounced effect on liver fibrosis.

AIM

This study aimed to determine the therapeutic potential of placenta-derived MSCs (PD-MSCs) in combination with Fx to treat liver fibrosis and evaluate their impact on the main links of liver fibrosis pathogenesis.

METHODS

After PD-MSCs isolation and identification, outbred ICR/CD1 mice were divided into five groups: Control group, CCl4 group (CCl4), Fx group (CCl4+Fx), PD-MSCs group (CCl4+MSCs) and cotreatment group (CCl4+MSCs+Fx). Biochemical histopathological investigations were performed. Semiquantitative analysis of the alpha-smooth muscle actin (α-SMA+), matrix metalloproteinases (MMP-9+, MMP-13+), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1+) areas, and the number of positive cells in them were studied by immunohistochemical staining. Transforming growth factor-beta (TGF-β), hepatic growth factor (HGF), procollagen-1 (COL1α1) in liver homogenate and proinflammatory cytokines in blood serum were determined using an enzyme immunoassay.

RESULTS

Compared to the single treatment with PD-MSCs or Fx, their combined administration significantly reduced liver enzyme activity, the severity of liver fibrosis, the proinflammatory cytokine levels, TGF-β level, α-SMA+, TIMP-1+ areas and the number of positive cells in them, and increased HGF level, MMP-13+, and MMP-9+ areas.

CONCLUSION

Fx enhanced the therapeutic potential of PD-MSCs in CCl4-induced liver fibrosis, but more investigations are necessary to understand the mutual impact of PD-MSCs and Fx.

Effects of preconditioning with TNFα and IFNγ in angiogenic potential of mesenchymal stromal cell-derived extracellular vesicles

Introduction: Mesenchymal stromal cells (MSCs) have demonstrated therapeutic properties both in vitro and in vivo to treat various diseases, including anti-inflammatory, immunomodulatory and pro-angiogenic effects. These therapeutic effects are mediated by their secretome composed of soluble factors and extracellular vesicles (EVs). The composition of EVs reflects the molecular and functional characteristics of parental cells. MSC preconditioning can alter the composition of EVs, thereby influencing their therapeutic potential. Methods: MSCs were subjected to preconditioning with two cytokines, TNFα and IFNγ. Following 24 h of preconditioning, MSC-EVs secreted into the culture supernatant were isolated through tangential filtration. Particle concentration and size distribution were measured by nanoparticle tracking analysis, and the surface antigen expression of the EV-specific CD63 was quantified via Enzyme Linked ImmunoSorbent Assay. The angiogenic potential of MSCEVs obtained after preconditioning MSCs was assessed by the analysis of their protein composition and their influence on human umbilical vein endothelial cell (HUVECs) proliferation, migration, and tube-forming ability. Results: Preconditioning with TNFα and IFNγ did not influence the MSC-EV profile but did induce changes in their protein content. Indeed, the expression of pro-angiogenic proteins increased in EVs from preconditioned MSCs compared to EVs from no-preconditioned MSCs. EVs from preconditioned MSCs tend to stimulate HUVEC migration, proliferation and tubeforming ability. These observations imply the presence of a pro-angiogenic potential in EVs obtained after preconditioning of MSCs with TNFα and IFNγ. Discussion: In conclusion, it appears that the pro-angiogenic potential of EVs is enhanced through preconditioning of MSCs with TNFα and IFNγ. The use of these MSCs-EVs in therapy would circumvent the limitations of current cell-based therapies. Indeed, the therapeutic potential of MSC-EVs presents an attractive strategy for exploiting the clinical benefits of MSC therapy. For example, in the field of regenerative medicine, the exploitation of cell-free therapy using highly pro-angiogenic MSC-EVs is of great interest.

Can extracellular vesicles be considered as a potential frontier in the treatment of intervertebral disc disease?

As a global public health problem, low back pain (LBP) caused by intervertebral disc degeneration (IDD) seriously affects patients' quality of life. In addition, the prevalence of IDD tends to be younger, which brings a huge burden to individuals and society economically. Current treatments do not delay or reverse the progression of IDD. The emergence of biologic therapies has brought new hope for the treatment of IDD. Among them, extracellular vesicles (EVs), as nanoscale bioactive substances that mediate cellular communication, have now produced many surprising results in the research of the treatment of IDD. This article reviews the mechanisms and roles of EVs in delaying IDD and describes the prospects and challenges of EVs.

The neuroprotective potential of mesenchymal stem cells from bone marrow and human exfoliated deciduous teeth in a murine model of demyelination

INTRODUCTION

Multiple sclerosis (MS) is characterized by chronic inflammation, demyelination, and axonal degeneration within the central nervous system (CNS), for which there is no current treatment available with the ability to promote neuroprotection or remyelination. Some aspects of the progressive form of MS are displayed in the murine cuprizone model, where demyelination is induced by the innate immune system without major involvement of the adaptive immune system. Mesenchymal stem cells (MSCs) are multipotent cells with immunomodulatory and neuroprotective potential. In this study, we aimed to assess the neuroprotective potential of MSCs from bone marrow (BM-MSCs) and stem cells from human exfoliated deciduous teeth (SHED) in the cuprizone model.

METHODS

Human BM-MSCs and SHED were isolated and characterized. Nine-week-old female C57BL/6 mice were randomized to receive either human BM-MSCs, human SHED or saline intraperitoneally. Treatments were administered on day -1, 14 and 21. Outcomes included levels of local demyelination and inflammation, and were assessed with immunohistochemistry and histology.

RESULTS

BM-MSCs were associated with increased myelin content and reduced microglial activation whereas mice treated with SHED showed reduced microglial and astroglial activation. There were no differences between treatment groups in numbers of mature oligodendrocytes or axonal injury. MSCs were identified in the demyelinated corpus callosum in 40% of the cuprizone mice in both the BM-MSC and SHED group.

CONCLUSION

Our results suggest a neuroprotective effect of MSCs in a toxic MS model, with demyelination mediated by the innate immune system.

Machine learning-based detection of adventitious microbes in T-cell therapy cultures using long-read sequencing

Assuring that cell therapy products are safe before releasing them for use in patients is critical. Currently, compendial sterility testing for bacteria and fungi can take 7-14 days. The goal of this work was to develop a rapid untargeted approach for the sensitive detection of microbial contaminants at low abundance from low volume samples during the manufacturing process of cell therapies. We developed a long-read sequencing methodology using Oxford Nanopore Technologies MinION platform with 16S and 18S amplicon sequencing to detect USP <71> organisms and other microbial species. Reads are classified metagenomically to predict the microbial species. We used an extreme gradient boosting machine learning algorithm (XGBoost) to first assess if a sample is contaminated, and second, determine whether the predicted contaminant is correctly classified or misclassified. The model was used to make a final decision on the sterility status of the input sample. An optimized experimental and bioinformatics pipeline starting from spiked species through to sequenced reads allowed for the detection of microbial samples at 10 colony-forming units (CFU)/mL using metagenomic classification. Machine learning can be coupled with long-read sequencing to detect and identify sample sterility status and microbial species present in T-cell cultures, including the USP <71> organisms to 10 CFU/mL. IMPORTANCE This research presents a novel method for rapidly and accurately detecting microbial contaminants in cell therapy products, which is essential for ensuring patient safety. Traditional testing methods are time-consuming, taking 7-14 days, while our approach can significantly reduce this time. By combining advanced long-read nanopore sequencing techniques and machine learning, we can effectively identify the presence and types of microbial contaminants at low abundance levels. This breakthrough has the potential to improve the safety and efficiency of cell therapy manufacturing, leading to better patient outcomes and a more streamlined production process.

Mechano-responsive hydrogel for direct stem cell manufacturing to therapy

Bone marrow-derived mesenchymal stem cell (MSC) is one of the most actively studied cell types due to its regenerative potential and immunomodulatory properties. Conventional cell expansion methods using 2D tissue culture plates and 2.5D microcarriers in bioreactors can generate large cell numbers, but they compromise stem cell potency and lack mechanical preconditioning to prepare MSC for physiological loading expected in vivo. To overcome these challenges, in this work, we describe a 3D dynamic hydrogel using magneto-stimulation for direct MSC manufacturing to therapy. With our technology, we found that dynamic mechanical stimulation (DMS) enhanced matrix-integrin β1 interactions which induced MSCs spreading and proliferation. In addition, DMS could modulate MSC biofunctions including directing MSC differentiation into specific lineages and boosting paracrine activities (e.g., growth factor secretion) through YAP nuclear localization and FAK-ERK pathway. With our magnetic hydrogel, complex procedures from MSC manufacturing to final clinical use, can be integrated into one single platform, and we believe this 'all-in-one' technology could offer a paradigm shift to existing standards in MSC therapy.

Umbilical cord blood derived cellular therapy: advances in clinical development

While cord blood (CB) is primarily utilized in allogeneic hematopoietic cell transplantation (HCT), the development of novel cell therapy products from CB is a growing and developing field. Compared to adult blood, CB is characterized by a higher percentage of hematopoietic stem cells (HSCs) and progenitor cells, less mature immune cells that retain a high capacity of proliferation, and stronger immune tolerance that requires less stringent HLA-matching when used in the allogenic setting. Given that CB is an FDA regulated product and along with its unique cellular composition, CB lends itself as a readily available and safe starting material for the development of off-the-shelf cell therapies. Moreover, non-hematologic cells such as mesenchymal stem cell (MSCs) residing in CB or CB tissue also have potential in regenerative medicine and inflammatory and autoimmune conditions. In this review, we will focus on recent clinical development on CB-derived cellular therapies in the field of oncology, including T-cell therapies such as chimeric antigen receptor (CAR) T-cells, regulatory T-cells, and virus-specific T-cells; NK-cell therapies, such as NK cell engagers and CAR NK-cells; CB-HCT and various modifications; as well as applications of MSCs in HCT.

Contrariety of Human Bone Marrow Mesenchymal Stromal Cell Functionality in Modulating Circulatory Myeloid and Plasmacytoid Dendritic Cell Subsets

Mesenchymal Stromal Cells (MSCs) derived from bone marrow are widely tested in clinical trials as a cellular therapy for potential inflammatory disorders. The mechanism of action of MSCs in mediating immune modulation is of wide interest. In the present study, we investigated the effect of human bone-marrow-derived MSCs in modulating the circulating peripheral blood dendritic cell responses through flow cytometry and multiplex secretome technology upon their coculture ex vivo. Our results demonstrated that MSCs do not significantly modulate the responses of plasmacytoid dendritic cells. However, MSCs dose-dependently promote the maturation of myeloid dendritic cells. Mechanistic analysis showed that dendritic cell licensing cues (Lipopolysaccharide and Interferon-gamma) stimulate MSCs to secret an array of dendritic cell maturation-associated secretory factors. We also identified that MSC-mediated upregulation of myeloid dendritic cell maturation is associated with the unique predictive secretome signature. Overall, the present study demonstrated the dichotomy of MSC functionality in modulating myeloid and plasmacytoid dendritic cells. This study provides clues that clinical trials need to investigate if circulating dendritic cell subsets in MSC therapy can serve as potency biomarkers.

Collagens Regulating Adipose Tissue Formation and Functions

The globally increasing prevalence of obesity is associated with the development of metabolic diseases such as type 2 diabetes, dyslipidemia, and fatty liver. Excess adipose tissue (AT) often leads to its malfunction and to a systemic metabolic dysfunction because, in addition to storing lipids, AT is an active endocrine system. Adipocytes are embedded in a unique extracellular matrix (ECM), which provides structural support to the cells as well as participating in the regulation of their functions, such as proliferation and differentiation. Adipocytes have a thin pericellular layer of a specialized ECM, referred to as the basement membrane (BM), which is an important functional unit that lies between cells and tissue stroma. Collagens form a major group of proteins in the ECM, and some of them, especially the BM-associated collagens, support AT functions and participate in the regulation of adipocyte differentiation. In pathological conditions such as obesity, AT often proceeds to fibrosis, characterized by the accumulation of large collagen bundles, which disturbs the natural functions of the AT. In this review, we summarize the current knowledge on the vertebrate collagens that are important for AT development and function and include basic information on some other important ECM components, principally fibronectin, of the AT. We also briefly discuss the function of AT collagens in certain metabolic diseases in which they have been shown to play central roles.

Dental Stem Cells SV40, a new cell line developed in vitro from human stem cells of the apical papilla

AIM

To establish and fully characterize a new cell line from human stem cells of the apical papilla (SCAPs) through immortalization with an SV40 large T antigen.

METHODOLOGY

Human SCAPs were isolated and transfected with an SV40 large T antigen and treated with puromycin to select the infected population. Expression of human mesenchymal surface markers CD73, CD90 and CD105 was assessed in the new cell line named Dental Stem Cells SV40 (DSCS) by flow cytometry at early and late passages. Cell contact inhibition and proliferation were also analysed. To evaluate trilineage differentiation, quantitative polymerase chain reaction and histological staining were performed.

RESULTS

DSCS cell flow cytometry confirmed the expression of mesenchymal surface markers even in late passages [100% positive for CD73 and CD90 and 98.9% for CD105 at passage (P) 25]. Fewer than 0.5% were positive for haematopoietic cell markers (CD45 and CD34). DSCS cells also showed increased proliferation when compared to the primary culture after 48 h, with a doubling time of 23.46 h for DSCS cells and 40.31 h for SCAPs, and retained the capacity to grow for >45 passages (150 population doubling) and their spindle-shaped morphology. Trilineage differentiation potential was confirmed through histochemical staining and gene expression of the chondrogenic markers SOX9 and COL2A1, adipogenic markers CEBPA and LPL, and osteogenic markers COL1A1 and ALPL.

CONCLUSIONS

The new cell line derived from human SCAPs has multipotency, retains its morphology and expression of mesenchymal surface markers and shows higher proliferative capacity even at late passages (P45). DSCS cells can be used for in vitro study of root development and to achieve a better understanding of the regenerative mechanisms.

The Stromal Vascular Fraction from Canine Adipose Tissue Contains Mesenchymal Stromal Cell Subpopulations That Show Time-Dependent Adhesion to Cell Culture Plastic Vessels

Adipose-derived mesenchymal stromal cells (MSCs) are extensively studied in both human and veterinary medicine. Their isolation is usually performed by collagenase digestion followed by filtration and removal of nonadherent tissue remnants 48 h after seeding. We observed that waste tissue fragments contain cells that adhere belatedly to the plastic. We aimed to investigate their basic properties to speculate on the possible existence of MSC subpopulations. Adipose tissue from three dogs was enzymatically digested. Three cell populations that adhered to the culture plastic 48, 96, and 144 h after seeding were obtained. After expansion, they were analyzed by flow cytometry for MSC-positive (CD90, CD44, and CD29) and -negative (CD14, MHCII, and CD45) markers as well as for endothelial, pericyte, and smooth muscle cell markers (CD31, CD146, and alpha-SMA). Furthermore, cells were assessed for viability, doubling time, and trilineage differentiation ability. No significant differences were found between the three subpopulations. As a result, this procedure has proven to be a valuable method for dramatically improving MSCs yield. As a consequence of cell recovery optimization, the amount of tissue harvested could be reduced, and the time required to obtain sufficient cells for clinical applications could be shortened. Further studies are needed to uncover possible different functional properties.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.

Efficacy of autologous mesenchymal stromal cell treatment for chronic degenerative musculoskeletal conditions in dogs: A retrospective study

Introduction

The objective of this study was to retrospectively analyze clinical data from a referral regenerative medicine practice, to investigate the efficacy of autologous mesenchymal stromal cells (MSC) in 245 dogs deemed unresponsive to conventional treatment by their referring vet.

Methods

Diagnostic imaging [radiology and musculoskeletal ultrasound (MSK-US)] identified musculoskeletal pathology holistically. MSCs, produced according to current guidelines, were initially administered with PRP by targeted injection to joints and/or tendons, with a second MSC monotherapy administered 12 weeks later to dogs with severe pathology and/or previous elbow arthroscopic interventions. Dogs with lumbosacral disease received epidural MSCs with additional intravenous MSCs administered to dogs with spondylosis of the cervical, thoracic and lumbar spine. All dogs received laser therapy at 10 J/cm2 at the time of treatment and for 5 sessions thereafter. Objective outcome measures (stance analysis, range of joint motion, pressure algometry) and validated subjective outcome measures (owner reported VetMetrica HRQL™ and veterinary pain and quality of life impact scores) were used to investigate short and long-term (6-104 weeks) efficacy. Outcome data were collected at predetermined time windows (0-6, 7-12, 13-18, 19-24, 25-48, 49-78, 79-104) weeks after initial treatment.

Results

There were statistically significant improvements in post compared with pre-treatment measures at all time windows in stance analysis, shoulder and hip range of motion, lumbosacral pressure algometry, and to 49-78 weeks in carpus and elbow range of motion. Improvements in 4 domains of quality of life as measured by VetMetricaTM were statistically significant, as were scores in vet-assessed pain and quality of life impact. In dogs receiving one initial treatment the mean time before a second treatment was required to maintain improvements in objective measures was 451 days. Diagnostic imaging confirmed the regenerative effects of MSCs in tendinopathies by demonstrating resolution of abnormal mineralization and restoration of normal fiber patterns.

Discussion

This represents the first study using "real-world" data to show that cell-based therapies, injected into multiple areas of musculoskeletal pathology in a targeted holistic approach, resulted in rapid and profound positive effects on the patient's pain state and quality of life which was maintained with repeat treatment for up to 2 years.

Cellular expansion of MSCs: Shifting the regenerative potential

Mesenchymal-derived stromal or progenitor cells, commonly called "MSCs," have attracted significant clinical interest for their remarkable abilities to promote tissue regeneration and reduce inflammation. Recent studies have shown that MSCs' therapeutic effects, originally attributed to the cells' direct differentiation capacity into the tissue of interest, are largely driven by the biomolecules the cells secrete, including cytokines, chemokines, growth factors, and extracellular vesicles containing miRNA. This secretome coordinates upregulation of endogenous repair and immunomodulation in the local microenvironment through crosstalk of MSCs with host tissue cells. Therapeutic applications for MSCs and their secretome-derived products often involve in vitro monolayer expansion. However, consecutive passaging of MSCs significantly alters their therapeutic potential, inducing a broad shift from a pro-regenerative to a pro-inflammatory phenotype. A consistent by-product of in vitro expansion of MSCs is the onset of replicative senescence, a state of cell arrest characterized by an increased release of proinflammatory cytokines and growth factors. However, little is known about changes in the secretome profile at different stages of in vitro expansion. Some culture conditions and bioprocessing techniques have shown promise in more effectively retaining the pro-regenerative and anti-inflammatory MSC phenotype throughout expansion. Understanding how in vitro expansion conditions influence the nature and function of MSCs, and their associated secretome, may provide key insights into the underlying mechanisms driving these alterations. Elucidating the dynamic and diverse changes in the MSC secretome at each stage of in vitro expansion is a critical next step in the development of standardized, safe, and effective MSC-based therapies.

Improved efficacy of mesenchymal stromal cells stably expressing CXCR4 and IL-10 in a xenogeneic graft versus host disease mouse model

Previous clinical trials have shown that mesenchymal stromal cells (MSCs) can modulate graft versus host disease (GvHD) after allogeneic hematopoietic transplantation, although with variable efficacy. To improve the anti-GvHD effect of these cells, adipose tissue derived-human MSCs (Ad-MSCs) were transduced with a lentiviral vector conferring stable expression of CXCR4, a molecule involved in cell migration to inflamed sites, and IL-10, a cytokine with potent anti-inflammatory properties. In vitro experiments showed that the expression of these molecules in Ad-MSCs (named CXCR4-IL10-MSCs) efficiently enhanced their migration towards SDF-1α and also improved their immunomodulatory properties compared to unmodified Ad-MSCs (WT-MSCs). Moreover, using a humanized GvHD mouse model, CXCR4-IL10-MSCs showed improved therapeutic effects, which were confirmed by histopathologic analysis in the target organs. Additionally, compared to WT-MSCs, CXCR4-IL10-MSCs induced a more marked reduction in the number of pro-inflammatory Th1 and Th17 cells, a higher polarization towards an anti-inflammatory T cell profile (CD3⁺-IL10⁺ cells), and increased the number of regulatory T and B cells. Our in vitro and in vivo studies strongly suggest that CXCR4-IL10-MSCs should constitute an important new generation of MSCs for the treatment of GvHD in patients transplanted with allogeneic hematopoietic grafts.

Thermal treatment of magnesium particles in polylactic acid polymer films elicits the expression of osteogenic differentiation markers and lipidome profile remodeling in human adipose stem cells

The efficacy of polylactic acid (PLA)/Magnesium (Mg)-based materials for driving stem cells toward bone tissue engineering applications requires specific Mg surface properties to modulate the interface of stem cells with the film. Here, we have developed novel PLA/Mg-based composites and explored their osteogenic differentiation potential on human adipose stem cells (hASCs). Mg-particles/polymer interface was improved by two treatments: heating in oxidative atmosphere (TT) and surface modification with a compatibilizer (PEI). Different contents of Mg particles were dispersed in PLA and composite surface and bulk properties, protein adsorption, stem cell-PLA/Mg interactions, osteogenic markers expressions, and lipids composition profile were evaluated. Mg particles were uniformly distributed on the surface and in the bulk PLA polymer. Improved and modulated particle-polymer adhesion was observed in Mg particle-treated composites. After 21 days in canonical growth culture conditions, hASCs on PLA/MgTT displayed the highest expression of the general osteogenic markers, RUNX2, SSP1, and BGLAP genes, Alkaline Phosphatase, type I Collagen, Osteopontin, and Calcium deposits. Moreover, by LC/MS QTOF mass-spectrophotometry lipidomic analysis, we found in PLA/MgTT-cells, for the first time, a remodeling of the lipid classes composition associated with the osteogenic differentiation. We ascribed these results to MgTT characteristics, which improve Mg availability and composite osteoinductive performance.

Skin-Derived ABCB5+ Mesenchymal Stem Cells for High-Medical-Need Inflammatory Diseases: From Discovery to Entering Clinical Routine

The ATP-binding cassette superfamily member ABCB5 identifies a subset of skin-resident mesenchymal stem cells (MSCs) that exhibit potent immunomodulatory and wound healing-promoting capacities along with superior homing ability. The ABCB5+ MSCs can be easily accessed from discarded skin samples, expanded, and delivered as a highly homogenous medicinal product with standardized potency. A range of preclinical studies has suggested therapeutic efficacy of ABCB5+ MSCs in a variety of currently uncurable skin and non-skin inflammatory diseases, which has been substantiated thus far by distinct clinical trials in chronic skin wounds or recessive dystrophic epidermolysis bullosa. Therefore, skin-derived ABCB5+ MSCs have the potential to provide a breakthrough at the forefront of MSC-based therapies striving to fulfill current unmet medical needs. The most recent milestones in this regard are the approval of a phase III pivotal trial of ABCB5+ MSCs for treatment of recessive dystrophic and junctional epidermolysis bullosa by the US Food and Drug Administration, and national market access of ABCB5+ MSCs (AMESANAR®) for therapy-refractory chronic venous ulcers under the national hospital exemption pathway in Germany.

PRISMA-Compliant Meta-Analysis of Randomized Controlled Trials on Osteoarthritis of Knee Managed with Allogeneic vs Autologous MSCs: Efficacy and Safety Analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVES

Our objective is to review the randomized controlled trials (RCTs) that have been conducted previously on the topic of osteoarthritis of the knee to assess and compare the efficacy and safety of autologous and allogeneic sources of mesenchymal stromal cells (MSCs) in the treatment of osteoarthritis.

MATERIALS AND METHODS

We searched the electronic databases PubMed, Embase, Web of Science, and the Cochrane Library until August 2021 for randomised controlled trials (RCTs) analysing the efficacy and safety of autologous and allogeneic sources of MSCs in the management of knee osteoarthritis. These searches were conducted independently and in duplicate. The outcomes that were taken into consideration for analysis were the visual analogue score (VAS) for pain, the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), the Lysholm score, and adverse events. The OpenMeta [Analyst] software was utilised to carry out the analysis in the R platform.

RESULTS

In total, 21 studies with a total of 936 patients were considered for this analysis. Because none of the studies made a direct comparison of the autologous and allogeneic sources of MSCs, we pooled the results of all of the included studies of both sources and made a comparative analysis of how the two types of MSCs fared in their respective applications. Although both allogeneic and autologous sources of MSCs demonstrated significantly better VAS improvement after 6 months (p = 0.006, p = 0.001), this trend was not maintained after 1 year for the allogeneic source (p = 0.171, p = 0.027). When compared to their respective controls based on WOMAC scores after 1 year, autologous sources (p = 0.016) of MSCs performed better than allogeneic sources (p = 0.186).A similar response was noted between the sources at 2 years in their Lysholm scores (p = 0.682, p = 0.017), respectively. Moreover, allogeneic sources (p = 0.039) of MSCs produced significant adverse events than autologous sources (p = 0.556) compared to their controls.

CONCLUSION

Our analysis of literature showed that autologous sources of MSCs stand superior to allogeneic sources of MSC with regard to their consistent efficacy for pain, functional outcomes, and safety. However, we strongly recommend that further studies be conducted that are of a high enough quality to validate our findings and reach a consensus on the best source of MSCs for use in cellular therapy treatments for knee osteoarthritis.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00751-z.

Administration Methods of Mesenchymal Stem Cells in the Treatment of Burn Wounds

Cellular therapies for burn wound healing, including the administration of mesenchymal stem or stromal cells (MSCs), have shown promising results. This review aims to provide an overview of the current administration methods in preclinical and clinical studies of bone-marrow-, adipose-tissue-, and umbilical-cord-derived MSCs for treating burn wounds. Relevant studies were identified through a literature search in PubMed and Embase and subjected to inclusion and exclusion criteria for eligibility. Additional relevant studies were identified through a manual search of reference lists. A total of sixty-nine studies were included in this review. Of the included studies, only five had clinical data from patients, one was a prospective case-control, three were case reports, and one was a case series. Administration methods used were local injection (41% in preclinical and 40% in clinical studies), cell-seeded scaffolds (35% and 20%), topical application (17% and 60%), and systemic injection (1% and 0%). There was great heterogeneity between the studies regarding experimental models, administration methods, and cell dosages. Local injection was the most common administration method in animal studies, while topical application was used in most clinical reports. The best delivery method of MSCs in burn wounds is yet to be identified. Although the potential of MSC treatment for burn wounds is promising, future research should focus on examining the effect and scalability of such therapy in clinical trials.

MSCs vs. iPSCs: Potential in therapeutic applications

Over the past 2 decades, mesenchymal stem cells (MSCs) have attracted a lot of interest as a unique therapeutic approach for a variety of diseases. MSCs are capable of self-renewal and multilineage differentiation capacity, immunomodulatory, and anti-inflammatory properties allowing it to play a role in regenerative medicine. Furthermore, MSCs are low in tumorigenicity and immune privileged, which permits the use of allogeneic MSCs for therapies that eliminate the need to collect MSCs directly from patients. Induced pluripotent stem cells (iPSCs) can be generated from adult cells through gene reprogramming with ectopic expression of specific pluripotency factors. Advancement in iPS technology avoids the destruction of embryos to make pluripotent cells, making it free of ethical concerns. iPSCs can self-renew and develop into a plethora of specialized cells making it a useful resource for regenerative medicine as they may be created from any human source. MSCs have also been used to treat individuals infected with the SARS-CoV-2 virus. MSCs have undergone more clinical trials than iPSCs due to high tumorigenicity, which can trigger oncogenic transformation. In this review, we discussed the overview of mesenchymal stem cells and induced pluripotent stem cells. We briefly present therapeutic approaches and COVID-19-related diseases using MSCs and iPSCs.

Hydrogel patch with pretreated stem cells accelerates wound closure in diabetic rats

Delay in wound healing is a diabetes mellites resulting disorder causing persistent microbial infections, pain, and poor quality of life. This disorder is treated by several strategies using natural biomaterials, growth factors and stem cells molded into various scaffolds which possess the potential to accelerate the closure of impaired diabetic wounds. In this study, we developed a hydrogel patch using chitosan (CS) and polyethylene glycol (PEG) with laden bone marrow-derived mesenchymal stem cells (BMSCs) that were pretreated with fibroblast growth factor 21 (FGF21). The developed hydrogel patches were characterized by scanning electron microscopy and fourier transform infrared (FTIR) spectroscopy. After studying the swelling behavior, growth factor (FGF21) was used to modulate BMSC in the hyperglycemic environment. Later, FGF21 treated BMSC were embedded in CS/PEG hydrogel patch and their wound closure effect was assessed in diabetic rats. The results showed that CS/PEG hydrogel patches have good biocompatibility and possess efficient BMSC recruiting properties. The application of CS/PEG hydrogel patches accelerated wound closure in diabetic rats as compared to the control groups. However, the use of FGF21 pretreated BMSCs laded CS/PEG hydrogel patches further increased the therapeutic efficacy of wound closure in diabetic rats. This study demonstrated that the application of a hydrogel patch of CS/PEG with FGF21 pretreated BMSCs improves diabetic wound healing, but further studies are needed on larger animals before the use of these dressings in clinical trials.

Bone marrow mesenchymal stem cells in premature ovarian failure: Mechanisms and prospects

Premature ovarian failure (POF) is a common female reproductive disorder and characterized by menopause, increased gonadotropin levels and estrogen deficiency before the age of 40 years old. The etiologies and pathogenesis of POF are not fully clear. At present, hormone replacement therapy (HRT) is the main treatment options for POF. It helps to ameliorate perimenopausal symptoms and related health risks, but can't restore ovarian function and fertility fundamentally. With the development of regenerative medicine, bone marrow mesenchymal stem cells (BMSCs) have shown great potential for the recovery of ovarian function and fertility based on the advantages of abundant sources, high capacity for self-renewal and differentiation, low immunogenicity and less ethical considerations. This systematic review aims to summarize the possible therapeutic mechanisms of BMSCs for POF. A detailed search strategy of preclinical studies and clinical trials on BMSCs and POF was performed on PubMed, MEDLINE, Web of Science and Embase database. A total of 21 studies were included in this review. Although the standardization of BMSCs need more explorations, there is no doubt that BMSCs transplantation may represent a prospective therapy for POF. It is hope to provide a theoretical basis for further research and treatment for POF.

Recent advances to enhance the immunomodulatory potential of mesenchymal stem cells

Considering the unique therapeutic potential of mesenchymal stem cells (MSCs), including their immunosuppressive and immunomodulatory properties as well as their ability to improve tissue regeneration, these cells have attracted the attention of scientists and clinicians for the treatment of different inflammatory and immune system mediated disorders. However, various clinical trials using MSCs for the therapeutic purpose are conflicting and differ from the results of promising preclinical studies. This inconsistency is caused by several factors such as poor migration and homing capacities, low survival rate, low level of proliferation and differentiation, and donor-dependent variation of the cells. Enhancement and retention of persistent therapeutic effects of the cells remain a challenge to overcome in MSC-based therapy. In this review, we summarized various approaches to enhance the clinical outcomes of MSC-based therapy as well as revised current and future perspectives for the creation of cellular products with improved potential for diverse clinical applications.

Stromal vascular fraction therapy for knee osteoarthritis: a systematic review

Background:

Regenerative cell therapies, such as adipose-derived stromal vascular fraction (SVF), have been postulated as potential treatments for knee osteoarthritis (KOA).

Objectives:

To assess the efficacy and safety of SVF treatment against placebo and other standard therapies for treating KOA in adult patients.

Design:

A systematic review.

Data sources and methods:

We searched the following databases: MEDLINE via PubMed, Epistemonikos, PEDro, DynaMed, TripDatabase, Elsevier via Clinicalkey and Cochrane Controlled Trials Register. We included prospective interventional studies where treatment with SVF in adults with KOA was compared against placebo or other standard therapies, and results were objectively measured with at least one widely recognised osteoarthritis scale.

Results:

Among 266 studies published until May 2021, nine met our inclusion criteria. A total of 239 patients (274 knees) were included in our study. The follow-up ranged from 6 to 24 months. Six studies had a control group (only one being placebo). All studies showed that SVF improved pain and functionality measured, in most cases, with the visual analogue scale and the Western Ontario and McMaster Universities Osteoarthritis Index. In addition, five studies reported an improvement in anatomical structures, as detected in MR images. However, the number of cells contained in SVF varied substantially between different studies, which could induce a comparison bias.

Conclusion:

Although based on a small number of dissimilar studies, SVF was considered a safe treatment for KOA and could be promising in terms of pain, functionality and anatomical structure improvement. However, SVF products need to be standardised, the number of cells homogenised and the use of concomitant treatments reduced to establish proper comparisons.

Registration:

PROSPERO registration number: CRD42021284187.