Current Stem Cell Research & Therapy - Volume 18, Issue 7, 2023

This review describes the current state of knowledge concerning interactions between mesenchymal stromal cells (MSCs) and neutrophils. MSCs are known as somatic multipotent cells with regenerative and anti-inflammatory abilities and immunomodulatory effects over other immune cells. Several studies reported that MSCs could affect the function and viability of neutrophils in their recruitment, activation, activity, survival, production of reactive oxygen species, phagocytosis capacity, and apoptosis. Moreover, neutrophils could be involved in the pro-metastatic effects of MSCs. Inversally, only a few studies pointed to the possibility of the opposite effect of neutrophils on MSCs. Understanding the interactions between MSCs and neutrophils could help promote therapeutic strategies using stromal cell-based therapeutic approaches, especially for hyper-immune pathologies, immunodeficiencies, and infectious diseases. However, further in vitro and in vivo studies are essential to determine the complete mechanisms of MSCs and neutrophils interaction.

Osteoarthritis (OA) is a degenerative joint disease characterized by the loss of cartilage, which seriously affects the quality of patient's life and may even cause permanent sequelae. The treatment of OA is diversified, mostly limited to relieving clinical symptoms. Less invasive treatments that can cure OA are still lacking. With the rise of tissue-cell engineering, stem cell therapy has gradually aroused great interest in treating OA. Cartilage stem/progenitor cells (CSPCs), a type of stem cell found on the surface of articular cartilage, have many similarities with mesenchymal stem cells (MSCs). These cells can be isolated and cultured from animals and humans and exist in articular cartilage over the body, such as the knee joint, patellofemoral joint, and temporomandibular joint. Due to their strong proliferative and chondrogenic differentiation abilities, CSPCs may contribute a lot to cartilage regeneration and repair in OA. We will provide an overview of the biological characteristics of CSPCs and their role in OA in combination with the research progress. Despite some existing limitations, CSPCs still offer an innovative idea for OA treatment with great advantages.

Hepatocytes are the major parenchymal cells (PC) in the liver and present an important role in liver metabolism. Hepatocytes are considered a gold standard tool for drug toxicity/screening or liver disease modeling. However, the maturation and functions of hepatocytes are lost under routine 2- dimensional (2D) culture conditions. Recent studies revealed that the interactions between hepatocytes and non-parenchyma cells (NPC) under 3D culture conditions can be an alternative option for optimizing hepatocyte maturation. Co-culture of hepatocytes with NPC simplifies the in-vitro liver disease models of fibrosis, steatosis and non-alcoholic fatty liver disease (NAFLD), cholestasis, and viral hepatitis. This review described the co-culture of liver PC with NPC under 2D and 3D culture systems.

Bone and cartilage regeneration is a dynamic and complex process involving multiple cell types, such as osteoblasts, osteoclasts, endothelial cells, etc. Stem cells have been proved to have an efficient capability to promote bone and cartilage regeneration and repair, but the usage of cells harbors some important safety issues, such as immune rejection and carcinogenicity. Exosomes are non-cell structures secreted from various cells. The content of exosomes is enriched with proteins, such as cytoskeleton proteins, adhesion factors, transcription factors, etc., and a variety of nucleic acids, such as mRNA (Messenger RNA), long-chain non-coding RNA, microRNA (miRNA), etc. Exosomes can deliver a variety of contents from the parent cells to the recipient cells in different tissue backgrounds, influencing the phenotype and function of the recipient cells. Recent studies have demonstrated that miRNAs play significant roles in bone formation, suggesting that miRNAs may be novel therapeutic targets for bone and cartilage diseases. Exosomes have been shown with low/no immune rejection in vivo, no carcinogenic risk of infection, nor other side effects. In recent years, stem cell exosomes have been utilized to promote bone and cartilage regeneration processes during bone defect, bone fracture, cartilage repair, osteoporosis, and osteoarthritis. In this review, we discuss different exosomes derived from stem cells and their interactions with target cells, including osteoblasts, chondrocytes and osteoclasts. We also highlight the various signaling pathways involved in stem cell exosome-related bone and cartilage regeneration.

Resistance to chemotherapy poses a major challenge for cancer treatment. Reactivating a stem cell program resembling that seen in embryonic development can lead cancer cells to acquire a stem-cell phenotype characterized by expression of stemness genes, pluripotency, high self-renewal ability, and tumor-initiating capability. These cancer stem cells (CSCs) are usually resistant to anticancer drugs and are likely involved in treatment failure in many cancer types. Ewing sarcoma (ES) is a pediatric cancer type typically resulting from a typical genetic alteration affecting bone or soft tissues. Despite advances in treatment, survival prognostic remains poor for patients with refractory or recurrent disease. Here, we review the increasing evidence indicating that ES tumors contain a CSC subpopulation expressing stem cell genes, including BM1, OCT3/4, NANOG, and SOX2, that plays a role in resistance to drug treatment, and current experimental strategies that successfully counteract chemoresistance mediated by CSCs in ES.

Over 50 years have passed since discovering mesenchymal stromal cells (MSCs). Initially, despite gaps in the knowledge of the identity of these cells, their therapeutic aspects were recognized. Consequently, MSCs became candidates for treating a wide range of diseases. However, the therapeutic effects of MSCs are not stable in the long term, and there are inconsistent data on their clinical efficacy. Even though more than 1000 MSC-based clinical trials have been registered, and the safety of MSCbased cell therapies has been proven, data on the clinical efficacy of MSCs have not been enough to warrant FDA approval for clinical treatment and marketing purposes. The available information on MSCs still contains some controversies, perhaps owing to little progress in understanding their in vivo identity. MSCs have been used for therapeutic purposes despite poor knowledge of their in vivo origin or functions. Hence, perhaps we need to go back to the basics of MSCs and spend more time understanding the biology of these cells. An improved understanding of MSCs' location and function within tissues may improve their therapeutic efficacy and, consequently, their establishment as a cell therapy product.

The utility of animal stem cells finds implications in enhancing milk, meat, and fiber production and serving animal models for human diseases. Stem cells are involved in tissue development, growth, and repair, and in regenerative therapy. Caprine embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and other tissue-specific adult stem cells (ASCs) have tremendous potential for their use in regenerative medicine. The application of goat ESCs, iPSCs, mammary stem cells (MaSC), mesenchymal stem cells (MSCs), spermatogonial stem cells (SSCs) and others can find their implication in increasing caprine production potential and human disease model. The onset of the disease and therapeutic effects of stem cells of many human diseases like sub-fertility, joint conditions, intervertebral disc defects, osteoarthritis, and chondrogenesis can be well studied in goats. Increasing evidence of MSCs and their secreted factors have drawn the attention of animal scientists in regenerative medicine. This review summarizes a comprehensive overview of research made on caprine stem cells and illustrates some potential applications of stem cells in caprine regenerative medicine and their utility as a model animal in understanding human diseases.

Background: Cell sheet technique using mesenchymal stem cells is a high-level strategy in periodontal regenerative medicine. Although recent studies have shown the role of MSCSs in increased dental supporting tissues and bone, there is no systematic review focused specifically on assessing periodontal regeneration in orthotopic animal models. Objective: To evaluate the potential of mesenchymal stem cell sheets (MSCSs) on periodontal regeneration, compared to control, in experimental animal models Methods: Pre-clinical studies in periodontal defects of animal models were considered eligible. The electronic search included the MEDLINE, Web of Science, EMBASE and LILACS databases. The review was conducted according to the Preferred Reporting Item for Systematic Reviews and Meta-Analyses statement guidelines. Results: A total of 17 of the 3989 studies obtained from the electronic database search were included. MSCSs included dental follicle (DF) MSCSs, periodontal ligament (PL) MSCSs, dental pulp (DP) MSCSs, bone marrow (BM) MSCSs, alveolar periosteal (AP) MSCSs and gingival (G) MSCSs. Regarding cell sheet inducing protocol, most of the studies used ascorbic acid (52.94%). Others used culture dishes grafted with a temperature-responsive polymer (47.06%). Adverse effects were not identified in the majority of studies. Meta-analysis was not considered because of methodological heterogeneities. PDL-MSCSs were superior for periodontal regeneration enhancement compared to the control, but in an induced inflammatory microenvironment, DF-MSCSs were better. Moreover, DF-MSCSs, DP-MSCSs, and BM-MSCSs showed improved results compared to the control. Conclusion: MSCSs can improve periodontal regeneration in animal periodontal defect models.

Objective: Intervertebral disc degeneration (IDD) represents one of the leading causes of low back pain. Research suggests the participation of LINC01116 in IDD progression. Herein, the current study explored the underlying mechanism of LINC01116 in IDD. Methods: The differential expression patterns of LINC01116 in IDD and normal tissues were analyzed using the GEO database. Human nucleus pulposus (NP) cells were provided and treated with IL-1β to establish IDD models in vitro. LINC01116 expression was detected and intervened. Indices such as cell proliferation, apoptosis, and extracellular matrix (ECM)-related factor expression were determined using CCK-8 assay, flow cytometry, and Western blotting. LINC01116 sublocation was identified by means of nuclear/cytosol fractionation assay. The binding relationships between LINC01116 and miR-9-5p and miR-9-5p and ZIC5 were verified by bioinformatics analysis, dual-luciferase assays, RNA immunoprecipitation (RIP) assay, and RNA-pull-down. Western blotting was conducted to measure the levels of the Wnt pathway key factors. Results and Discussion: LINC01116 was highly expressed in the degenerative NP cells. Silencing of LINC01116 critically promoted degenerative NP cell proliferation and inhibited apoptosis and ECM loss. LINC01116 was located in the cytoplasm. In degenerative NP cell models, LINC01116 could competitively bind to miR-9-5p to elevate ZIC5 expression. LINC01116 induced NP cell apoptosis and impeded NP cell proliferation and ECM synthesis by inhibiting miR-9-5p and miR-9-5p targeted ZIC5. ZIC5 could effectively increase the levels of the Wnt pathway-related factors. Conclusion: Silencing LINC01116 blocked its adsorption of miR-9-5p as a sponge to promote the miR-9- 5p expression and inhibit ZIC5/Wnt activation, thus impacting NP cell biological functions.

Background: Repair of the nervous system in humans has always been complicated and faced difficulties. Cell transplantation approaches using biocompatible scaffolds might be an attractive therapeutic strategy for neuronal regeneration. Objective: We designed a cell delivery platform based on polyurethane [PU] and modified it with iron oxide nanoparticles [Fe2O3 NPs] for neural induction of human-induced pluripotent stem cells [hiPSC]. Forskolin, IBMX, and different ratios of FBS were employed to induce neurogenesis of hiPSCs. Neural differentiations were assessed at the level of genes and proteins. Methods: As was shown by MTT colorimetric assay, the proliferation and viability of SNL 76/7 on PU/ Fe2O3 were superior in comparison with pure PU and Fe2O3. hiPSCs cultured with PU/Fe2O3 exhibited an elevated expression of β3-tubulin, MAP2, NSE, OLIG2, as compared to controls. Furthermore, Acridine Orange staining assured the survival and viability of hiPSCs after 14 days of differentiation. Results: All in all, our findings pointed out the biocompatibility and positive regulatory effect of PU/Fe2O3 on neural markers. Conclusion: We believe this scaffold could be a potential candidate for future nerve differentiation applications.

Background: Endometrial injury is considered the major cause of female infertility. Traditional therapies such as estrogen substitution therapy are not satisfactory due to individual variation in response to treatment, thereby warranting the use of alternative strategies such as stem cell therapy. Transplantation of stem cells, such as umbilical cord mesenchymal stem cells (UCMSCs), has been shown to improve endometrial healing. However, due to the effect of the intrauterine environment, the therapeutic effect of UCMSCs is limited, and its efficacy is unstable. HOXA10, encoded by the HOXA10 gene, plays an important role in endometrium morphology maintenance, proliferation, differentiation, and embryo implantation. Moreover, UCMSCs do not show HOXA10 expression. Objective: Our study aimed to evaluate the therapeutic effects of HOXA10-transfected UCMSCs on endometrial injury repair in vivo. Methods: First, we established T10-UCMSCs (UCMSCs transfected with HOXA10) for transplantation. To establish the endometrial injury model, we injected 95% ethanol into the uterine cavity and transplanted T10-UCMSCs into the uterine cavity from the cornua uteri. Fourteen days later, uteri were collected for histological and biochemical analysis of endometrial growth and receptivity. Results: Our results showed the endometrial receptivity was better in T10-UCMSCs group than in UCMSCs group, suggesting that HOXA10 could enhance the repairing ability of UCMSCs in the endometrium injury repair. More importantly, the fertility test showed that more embryos were implanted in the T10- UCMSCs group. Conclusion: Our results suggest that UCMSCs with HOXA10 expression could improve the therapeutic effects on endometrial injury repairing.

Introduction: Back pain causes tremendous patient suffering and high financial cost to the healthcare system. Mesenchymal Stem Cells (MSCs) have demonstrated the ability to enhance healing and reduce inflammation and pain without the deleterious side effects of corticosteroids and nonsteroidal anti-inflammatory drugs in numerous clinical series for peripheral joint arthritis. We hypothesized that translaminar MSC injection into the epidural space would effectively treat disc arthritis without the burden of sedation and the risks of disc space injection. We further hypothesized that MSC injection into the facet joints would effectively and safely treat facet joint-induced back pain. The combination of epidural and facet joint injection would potentially treat the most recognized low back pain generators with virtually complete safety. Objective: We present the initial results for the first patient enrolled in phase 1 clinical trial of the efficacy and safety of allogeneic MSCs when injected translaminarly and into the facet joints for the treatment of recalcitrant discogenic and arthritic back pain. Case Report: A 47-year-old male presented with complaints of 13-year-long chronic lower back pain resistant to conservative treatment. The decision was made to treat the patient with umbilical cord-derived MSCs. 87 million MSCs were infused intravenously. Simultaneously, 1 million cells were injected into each of the 8 lumbar epidural facet joints and 5 million cells into the lumbar epidural space. The patient had no adverse events or complications related to the treatment. Five days after treatment, most of his lumbar pain was gone, and his back spasms stopped. He no longer needed to take acetaminophen or ibuprofen and had no difficulty sleeping without medications. The patient also reported his residual cervical radicular pain to be 98% resolved due to the injection. Conclusion: We have demonstrated for the first time that MSC injection into the lumbar facet joints and epidural space results in significant improvement of lower back pain and can improve symptoms in other spinal regions without engendering the risks associated with intradiscal injections or epidural use of corticosteroids.

Introduction: Due to the rapid progression of COVID-19 to severe and critical stages, thousands of patients have required the use of intensive care unit (ICU) treatment, placing an excessive strain on health systems. Immunomodulatory effects of Wharton’s Jelly Mesenchymal Stem Cells (WJ-MSCs) have shown promising results in the treatment of patients with COVID-19. However, the effect of promptly applied cell therapy on ambulatory patient prognosis has not been described. This case report presents the clinical outcome of a multimorbid, steroid-hypersensitive, COVID-19 patient treated with WJ-MSCs transplantation. Case presentation: A 67-year-old woman with Type 2 diabetes, overweight (82 kg, 168 cm, BMI = 29.053), hypertension (190/60 mmHg) and steroid-hypersensitivity, tested positive for COVID-19 after presenting typical symptoms such as fatigue, chest pain, myalgia, nasal congestion, dysgeusia, anosmia and oxygen saturation (SpO2) 94% - 96%, with normal body temperature (36°C). The patient received pharmacologic treatment but, when symptoms worsened, WJ-MSCs were transplanted to modulate the suspected onset of the cytokine release syndrome. Significant improvement of symptoms and clinical parameters (inflammatory markers and CT score) was observed, and the patient fully recovered within a short period of time. Conclusion: The present case report exhibits the favorable outcome of using Wharton’s Jelly Mesenchymal Stem Cells (WJ-MSCs) as an ambulatory and adjuvant therapy for COVID-19. Prompt WJ-MSCs infusion can be a safe ambulatory adjuvant therapy in COVID-19 infection care, preventing disease progression to critical stages and avoiding hospital overcrowding.

Introduction: Asthma is a heterogeneous disorder characterized by chronic airway inflammation resulting in obstructive pulmonary symptoms. In preclinical studies, mesenchymal stem cells (MSCs) have demonstrated the ability to ameliorate the symptoms and immunologic pathways seen in asthma. Due to the known relationship between asthma and the hyper-responsive immune cascade, we hypothesized that MSCs could be an effective treatment option for patients with asthma due to their significant immunomodulatory properties. Objective: We present the initial results for the first patient enrolled in a phase 1 clinical trial (Safety of Cultured Allogeneic Adult Umbilical Cord Derived Mesenchymal Stem Cell Intravenous Infusion for the Treatment of Pulmonary Diseases). Case Report: A 68-year-old male with a longstanding history of asthma requested mesenchymal stem cell treatment for his persistent asthma symptoms. Cultured umbilical cord-derived mesenchymal stem cells were infused intravenously at a dose of 100 million cells over a period of 40 minutes. Post-treatment follow- up was performed after two and six months. Results: The patient had no adverse events or complications related to treatment. In the two months posttreatment, his usage of a rescue inhaler decreased to 1 time per month, over 90% reduction. In addition, he had a 70% reduction in nebulizer usage. Improvement was sustained in the 6 months follow-up. Conclusion: We report the first case of mesenchymal stem cell treatment significantly and safely improving asthma clinical symptoms in a human. Additionally, an extensive literature review provided several plausible mechanisms by which stem cells can ameliorate immune hyper-stimulation associated with asthma.