Novel insights for improving the therapeutic safety and efficiency of mesenchymal stromal cells

Effectiveness of intraglandular allogeneic mesenchymal stem cell administration for treating chronic vesicular adenitis in bulls

This study aimed to evaluate the effects of the application of allogeneic mesenchymal stem cells (MSCs) bilaterally and intraglandularly in the vesicular glands of bulls affected by seminal vesiculitis. Twelve bulls that presented chronic vesiculitis with two or more recurrences were selected at Semen Collection and Processing Centres, based on the presence of pus in the semen, leukocytes on the motility and vigour evaluation slide, reactive to the California Mastitis Test - CMT (one cross or more) and the presence of leukocytes on a slide stained by Diff Quik staining with more than 5 polymorphonuclear cells (PMN) per field. Ultrasound examination of the vesicular glands was performed, and the clinical signs were definitive for the diagnosis. The proposed method of the intraglandular injection of MSCs involved application through the ischiorectal fossa with a long needle measuring 30-35 cm and a guide measuring 25-30 cm in length directly into the affected vesicular glands. The MSCs were cultured and frozen in the Bio Cell Cellular Therapy® laboratory (Brasilia, Brazil) and prepared by washing and centrifugation for intraglandular injection on the day of application. In total, 3x106 MSCs were injected into each vesicular gland. Data were evaluated for normality of residuals using the Shapiro-Wilk test. When the normality of the test was significant (P < 0.05), the data were transformed or outliers were removed and reevaluated. The "T-Test" was applied to identify statistical differences between variables before and after treatment. The probability of P ≤ 0.05 was considered a significant difference. Data were presented as the mean ± standard error of the mean (S.E.M.). Improvements were observed in the initial percent motility from 60.09 ± 4.8 to 69.89 ± 4.6 (P < 0.05), as well as in the post-thawing percent motility from 26.26 ± 6.77 to 42.5 ± 5 0.99 (P < 0.05). The number of doses produced increased significantly after treatment with MSCs, from 95.61 ± 23.31 units to 337.84 ± 67.75 units (P < 0.05) per ejaculate. The number of leukocytes observed per field decreased from 5.83 ± 0.48 to zero, demonstrating the recovery of the inflamed vesicular glands. Based on the results presented, it was concluded that the application of 3x106 MSCs in the vesicular glands of bulls with vesiculitis is safe and efficient, as it improved several parameters evaluated in this research, mainly the production of semen doses per ejaculate.

Heat shock-pretreated bone marrow mesenchymal stem cells accelerate wound healing in a diabetic foot ulcer rat model

BACKGROUND

Diabetic foot ulcers (DFUs) are the severe chronic complications of diabetes, amputation is required when ulcers cause severe loss of tissue or evoke a life-threatening infection. Mesenchymal stem cells (MSCs) have shown a good effect in helping DFU healing, though the efficiency needs to be improved. This study aimed to investigate the effects of heat shock pretreatment on the improvement of the therapeutic effects of MSCs.

METHODS

Primary rat bone marrow MSCs (BMSCs) were isolated and stimulated with heat shock pretreatment and then tested on a DFU rat model. Alkaline phosphatase, Alizarin Red S, and Oil Red O were stained to check the osteogenic differentiation ability of heat shock-pretreated BMSCs. The effect of heat shock pretreatment on the inflammatory response of macrophages was studied with the lipopolysaccharides stimulation model on a mouse macrophage cell line RAW264.7. The impact of heat shock-pretreated BMSCs on dermal fibroblasts was also checked. Last, heat shock-pretreated BMSCs were tested on a DFU rat model.

RESULTS

Heat shock-pretreated BMSCs were characterized by the expression of CD105 and CD44. Heat shock pre-stimulation did not affect cell viability when cultured up to 96 h. Heat shock pre-stimulated BMSCs inhibited the inflammatory response by reducing the pro-inflammatory cytokine production (IL-1β, IL-6, and TNF-α) and enhancing the anti-inflammatory cytokine production (IL-10) (at least all p < 0.01), as well as increasing the ratio of M2 polarization macrophages to M1 polarization in vitro (p < 0.001). Heat shock pre-stimulated BMSCs enhanced the growth and migration of dermal fibroblasts in vitro (p < 0.001). Heat shock-BMSCs promoted the M2 polarization level of macrophages in wound tissues in a DFU rat model.

CONCLUSION

Heat shock pretreatment could enhance the therapeutic effect of BMSCs on wound healing in a DFU rat model.

Cell origin and microenvironment: The players of differentiation capacity in human mesenchymal stem cells

Mesenchymal stem cells (MSCs) have several important properties that make them desirable for regenerative medicine. These properties include immunomodulatory ability, growth factor production, and differentiation into various cell types. Despite extensive research and promising results in clinical trials, our understanding of MSC biology, their mechanism of action, and their targeted and routine use in clinics is limited. Differentiation of human MSCs (hMSCs) is a complex process influenced by various elements such as growth factors, pharmaceutical compounds, microRNAs, 3D scaffolds, and mechanical and electrical stimulation. Research has shown that different culture conditions can affect the differentiation potential of hMSCs obtained from multiple fetal and adult sources. Additionally, it seems that what affects the differentiation capacities of these cells is their secretory characteristics, which are influenced by the origin of the cells and the local microenvironment where the cells are located. The review can provide insights into the microenvironment-based mechanisms involved in MSC differentiation, which can be valuable for future therapeutic applications.

Replicative senescence in amniotic fluid-derived mesenchymal stem cells and its impact on their immunomodulatory properties

The expansion of mesenchymal stem cells (MSCs) for clinical applications is often limited by replicative senescence, a growth arrest induced by various stresses during in vitro culture, yet its impact on the immunomodulatory properties of MSCs remains unclear. This study derived MSCs from the amniotic fluid (AF-MSCs) of seven first-trimester pregnancies, characterized them through flow cytometry, and evaluated their osteogenic differentiation potential before expanding the cells to compare immunoregulatory gene expression in proliferative and senescent states. Additionally, an assessment of the adipogenic differentiation potential of AF-MSCs from three samples was conducted following their recovery from approximately 9 months of cryopreservation, with results showing that these recovered cells retain the capacity for adipogenic differentiation. Molecular analysis revealed no significant differences in the expression of key immunoregulatory genes, such as TGFβ, IL-10, IDO, and VCAM-1, between proliferative and senescent cells, although senescent cells showed downregulation of FASL and upregulation of IL-6, COX1, and HLA-G. Markers of cell proliferation, including FOXM1 and B-MYB, were significantly downregulated in senescent cells, confirming the progression of replicative senescence. Despite expectations, the results indicated that some immunomodulatory markers remained stable or were even enhanced in senescent AF-MSCs. These findings highlight the resilience of AF-MSC immunomodulatory properties during prolonged in vitro expansion, supporting their potential for therapeutic applications despite the challenges posed by replicative senescence.

The Immunological Profile of Adipose Mesenchymal Stromal/Stem Cells after Cell Expansion and Inflammatory Priming

BACKGROUND

AT-MSCs display great immunoregulatory features, making them potential candidates for cell-based therapy. This study aimed to evaluate the "RBC lysis buffer" isolation protocol and immunological profiling of the so-obtained AT-MSCs.

METHODS

We established an immune-comparative screening of AT-MSCs throughout in vitro cell expansion (PM, P1, P2, P3, P4) and inflammatory priming regarding the expression of 28 cell-surface markers, 6 cytokines/chemokines, and 10 TLR patterns.

FINDINGS

AT-MSCs were highly expandable and sensitive to microenvironment challenges, hereby showing plasticity in distinct expression profiles. Both cell expansion and inflammation differentially modulated the expression profile of CD34, HLA-DR, CD40, CD62L, CD200 and CD155, CD252, CD54, CD58, CD106, CD274 and CD112. Inflammation resulted in a significant increase in the expression of the cytokines IL-6, IL-8, IL-1β, IL-1Ra, CCL5, and TNFα. Depending on the culture conditions, the expression of the TLR pattern was distinctively altered with TLR1-4, TLR7, and TLR10 being increased, whereas TLR6 was downregulated. Protein network and functional enrichment analysis showed that several trophic and immune responses are likely linked to these immunological changes.

CONCLUSIONS

AT-MSCs may sense and actively respond to tissue challenges by modulating distinct and specific pathways to create an appropriate immuno-reparative environment. These mechanisms need to be further characterized to identify and assess a molecular target that can enhance or impede the therapeutic ability of AT-MSCs, which therefore will help improve the quality, safety, and efficacy of the therapeutic strategy.

Priming mesenchymal stem cells to develop "super stem cells"

The stem cell pre-treatment approaches at cellular and sub-cellular levels encompass physical manipulation of stem cells to growth factor treatment, genetic manipulation, and chemical and pharmacological treatment, each strategy having advantages and limitations. Most of these pre-treatment protocols are non-combinative. This editorial is a continuum of Li et al's published article and Wan et al's editorial focusing on the significance of pre-treatment strategies to enhance their stemness, immunoregulatory, and immunosuppressive properties. They have elaborated on the intricacies of the combinative pre-treatment protocol using pro-inflammatory cytokines and hypoxia. Applying a well-defined multi-pronged combinatorial strategy of mesenchymal stem cells (MSCs), pre-treatment based on the mechanistic understanding is expected to develop "Super MSCs", which will create a transformative shift in MSC-based therapies in clinical settings, potentially revolutionizing the field. Once optimized, the standardized protocols may be used with slight modifications to pre-treat different stem cells to develop "super stem cells" with augmented stemness, functionality, and reparability for diverse clinical applications with better outcomes.

Anti-inflammatory and immunomodulatory effects of mesenchymal stem cell therapy on parasitic drug resistance

INTRODUCTION

The emergence of antiparasitic drug resistance poses a concerning threat to animals and humans. Mesenchymal Stem Cells (MSCs) have been widely used to treat infections in humans, pets, and livestock. Although this is an emerging field of study, the current review outlines possible mechanisms and examines potential synergism in combination therapies and the possible harmful effects of such an approach.

AREAS COVERED

The present study delved into the latest pre-clinical research on utilizing MSCs to treat parasitic infections. As per investigations, the introduction of MSCs to patients grappling with parasitic diseases like schistosomiasis, malaria, cystic echinococcosis, toxoplasmosis, leishmaniasis, and trypanosomiasis has shown a reduction in parasite prevalence. This intervention also alters the levels of both pro- and anti-inflammatory cytokines. Furthermore, the combined administration of MSCs and antiparasitic drugs has demonstrated enhanced efficacy in combating parasites and modulating the immune response.

EXPERT OPINION

Mesenchymal stem cells are a potential solution for addressing parasitic drug resistance. This is mainly because of their remarkable immunomodulatory abilities, which can potentially help combat parasites' resistance to drugs.

The Promising Role of a Zebrafish Model Employed in Neural Regeneration Following a Spinal Cord Injury

Spinal cord injury (SCI) is a devastating event that results in a wide range of physical impairments and disabilities. Despite the advances in our understanding of the biological response to injured tissue, no effective treatments are available for SCIs at present. Some studies have addressed this issue by exploring the potential of cell transplantation therapy. However, because of the abnormal microenvironment in injured tissue, the survival rate of transplanted cells is often low, thus limiting the efficacy of such treatments. Many studies have attempted to overcome these obstacles using a variety of cell types and animal models. Recent studies have shown the utility of zebrafish as a model of neural regeneration following SCIs, including the proliferation and migration of various cell types and the involvement of various progenitor cells. In this review, we discuss some of the current challenges in SCI research, including the accurate identification of cell types involved in neural regeneration, the adverse microenvironment created by SCIs, attenuated immune responses that inhibit nerve regeneration, and glial scar formation that prevents axonal regeneration. More in-depth studies are needed to fully understand the neural regeneration mechanisms, proteins, and signaling pathways involved in the complex interactions between the SCI microenvironment and transplanted cells in non-mammals, particularly in the zebrafish model, which could, in turn, lead to new therapeutic approaches to treat SCIs in humans and other mammals.

The Medicinal Potential of Mesenchymal Stem/Stromal Cells in Immuno- and Cancer Therapy

Cancer is a highly lethal disease that causes millions of deaths worldwide, thus representing a major public health challenge [...].

HOTAIRM1 Maintained the Malignant Phenotype of tMSCs Transformed by GSCs via E2F7 by Binding to FUS

Objective. Mesenchymal stromal/stem cells (MSCs) are an important part of the glioma microenvironment and are involved in the malignant progression of glioma. In our previous study, we showed that MSCs can be induced to a malignant phenotype (tMSCs) by glioma stem cells (GSCs) in the microenvironment. However, the potential mechanism by which tMSCs maintain their malignant phenotype after malignant transformation has not been fully clarified. Methods. The expression of HOTAIRM1, FUS, and E2F7 was detected by qRT-PCR. Clone formation, EdU, and Transwell assay were used to explore the role of HOTAIRM1, FUS, and E2F7 on the proliferation, migration, and invasion of tMSCs. Bioinformatics analysis and RNA immunoprecipitation were used to explore the relation among HOTAIRM1, FUS, and E2F7. Results. HOTAIRM1 was upregulated in tMSCs compared with MSCs. Loss- and gain-of-function assays showed that HOTAIRM1 promoted the proliferation, migration, and invasion of tMSCs. qRT-PCR and functional assays revealed that E2F7 might be the downstream target of HOTAIRM1. A further study of the mechanism showed that HOTAIRM1 could bind to FUS, an RNA-binding protein (RBP), and thus regulate E2F7, which could promote the malignant phenotype of tMSCs. Conclusion. Our study revealed that the HOTAIRM1/FUS/E2F7 axis is involved in the malignant progression of tMSCs transformed by GSCs in the glioma microenvironment and may function as a novel target for glioma therapy.

Roles of Mesenchymal Cells in the Lung: From Lung Development to Chronic Obstructive Pulmonary Disease

Mesenchymal cells are an essential cell type because of their role in tissue support, their multilineage differentiation capacities and their potential clinical applications. They play a crucial role during lung development by interacting with airway epithelium, and also during lung regeneration and remodeling after injury. However, much less is known about their function in lung disease. In this review, we discuss the origins of mesenchymal cells during lung development, their crosstalk with the epithelium, and their role in lung diseases, particularly in chronic obstructive pulmonary disease.

Mesenchymal Stem Cell-Derived Exosomes: Applications in Regenerative Medicine

Exosomes are a type of extracellular vesicles, produced within multivesicular bodies, that are then released into the extracellular space through a merging of the multivesicular body with the plasma membrane. These vesicles are secreted by almost all cell types to aid in a vast array of cellular functions, including intercellular communication, cell differentiation and proliferation, angiogenesis, stress response, and immune signaling. This ability to contribute to several distinct processes is due to the complexity of exosomes, as they carry a multitude of signaling moieties, including proteins, lipids, cell surface receptors, enzymes, cytokines, transcription factors, and nucleic acids. The favorable biological properties of exosomes including biocompatibility, stability, low toxicity, and proficient exchange of molecular cargos make exosomes prime candidates for tissue engineering and regenerative medicine. Exploring the functions and molecular payloads of exosomes can facilitate tissue regeneration therapies and provide mechanistic insight into paracrine modulation of cellular activities. In this review, we summarize the current knowledge of exosome biogenesis, composition, and isolation methods. We also discuss emerging healing properties of exosomes and exosomal cargos, such as microRNAs, in brain injuries, cardiovascular disease, and COVID-19 amongst others. Overall, this review highlights the burgeoning roles and potential applications of exosomes in regenerative medicine.

Extracellular Vesicles of Mesenchymal Stem Cells: Therapeutic Properties Discovered with Extraordinary Success

Mesenchymal stem cells (MSCs), the cells distributed in the stromas of the body, are known for various properties including replication, the potential of various differentiations, the immune-related processes including inflammation. About two decades ago, these cells were shown to play relevant roles in the therapy of numerous diseases, dependent on their immune regulation and their release of cytokines and growth factors, with ensuing activation of favorable enzymes and processes. Such discovery induced great increase of their investigation. Soon thereafter, however, it became clear that therapeutic actions of MSCs are risky, accompanied by serious drawbacks and defects. MSC therapy has been therefore reduced to a few diseases, replaced for the others by their extracellular vesicles, the MSC-EVs. The latter vesicles recapitulate most therapeutic actions of MSCs, with equal or even better efficacies and without the serious drawbacks of the parent cells. In addition, MSC-EVs are characterized by many advantages, among which are their heterogeneities dependent on the stromas of origin, the alleviation of cell aging, the regulation of immune responses and inflammation. Here we illustrate the MSC-EV therapeutic effects, largely mediated by specific miRNAs, covering various diseases and pathological processes occurring in the bones, heart and vessels, kidney, and brain. MSC-EVs operate also on the development of cancers and on COVID-19, where they alleviate the organ lesions induced by the virus. Therapy by MSC-EVs can be improved by combination of their innate potential to engineering processes inducing precise targeting and transfer of drugs. The unique properties of MSC-EVs explain their intense studies, carried out with extraordinary success. Although not yet developed to clinical practice, the perspectives for proximal future are encouraging.