Trabecular Meshwork Regeneration for Glaucoma Treatment Using Stem Cell-Derived Trophic Factors.

Glaucoma is one of the leading causes of irreversible blindness. Stem cell therapy has shown promise in the treatment of primary open-angle glaucoma in animal models. Stem cell-free therapy using stem cell-derived trophic factors might be in demand in patients with high-risk conditions or religious restrictions. In this chapter, we describe methods for trabecular meshwork stem cell (TMSC) cultivation, secretome harvesting, and protein isolation, as well as assays to ensure the health of TMSC post-secretome harvesting and for secretome periocular injection into mice for therapeutic purposes.

Generating ESC-Derived RGCs for Cell Replacement Therapy.

In several ocular diseases, degeneration of retinal neurons can lead to permanent blindness. Transplantation of stem cell (SC)-derived RGCs has been proposed as a potential therapy for RGC loss. Although there are reports of successful cases of SC-derived RGC transplantation, achieving long-distance regeneration and functional connectivity remains a challenge. To address these hurdles, retinal organoids are being used to study the regulatory mechanism of stem cell transplantation. Here we present a modified protocol for differentiating human embryonic stem cells (ESCs) into retinal organoids and transplanting organoid-derived RGCs into the murine eyes.

Mid- to long-term efficacy and safety of stem cell therapy for acute myocardial infarction: a systematic review and meta-analysis.

BACKGROUND: This comprehensive systematic review and meta-analysis investigated the mid- to long-term efficacy and safety of stem cell therapy in patients with acute myocardial infarction (AMI). METHODS: The study encompassed 79 randomized controlled trials with 7103 patients, rendering it the most up-to-date and extensive analysis in this field. This study specifically focused on the impact of stem cell therapy on left ventricular ejection fraction (LVEF), major adverse cardiac events (MACE), and infarct size. RESULTS: Stem cell therapy significantly improved LVEF at 6, 12, 24, and 36 months post-transplantation compared to control values, indicating its potential for long-term cardiac function enhancement. A trend toward reduced MACE occurrence was observed in the intervention groups, suggesting the potential of stem cell therapy to lower the risk of cardiovascular death, reinfarction, and stroke. Significant LVEF improvements were associated with long cell culture durations exceeding 1 week, particularly when combined with high injected cell quantities (at least 108 cells). No significant reduction in infarct size was observed. CONCLUSIONS: This review highlights the potential of stem cell therapy as a promising therapeutic approach for patients with AMI, offering sustained LVEF improvement and a potential reduction in MACE risk. However, further research is required to optimize cell culture techniques, determine the optimal timing and dosage, and investigate procedural variations to maximize the efficacy and safety of stem cell therapy in this context.

Functional outcome of the anterior vaginal wall in a pelvic surgery injury rat model after treatment with stem cell-derived progenitors of smooth muscle cells.

BACKGROUND: Stem-cell-derived therapy is a promising option for tissue regeneration. Human iPSC-derived progenitors of smooth muscle cells (pSMCs) exhibit limited proliferation and differentiation, which minimizes the risk of tumor formation while restoring smooth muscle cells (SMCs). Up to 29% of women suffer from recurrence of vaginal prolapse after prolapse surgery. Therefore, there is a need for therapies that can restore vaginal function. SMCs contribute to vaginal tone and contractility. We sought to examine whether human pSMCs can restore vaginal function in a rat model. METHODS: Female immunocompromised RNU rats were divided into 5 groups: intact controls (n = 12), VSHAM (surgery + saline injection, n = 35), and three cell-injection groups (surgery + cell injection using pSMCs from three patients, n = 14/cell line). The surgery to induce vaginal injury was analogous to prolapse surgery. Menopause was induced by surgical ovariectomy. The vagina, urethra, bladder were harvested 10 weeks after surgery (5 weeks after cell injection). Organ bath myography was performed to evaluate the contractile function of the vagina, and smooth muscle thickness was examined by tissue immunohistochemistry. Collagen I, collagen III, and elastin mRNA and protein expressions in tissues were assessed. RESULTS: Vaginal smooth muscle contractions induced by carbachol and KCl in the cell-injection groups were significantly greater than those in the VSHAM group. Collagen I protein expression in the vagina of the cell-injections groups was significantly higher than in the VSHAM group. Vaginal elastin protein expression was similar between the cell-injection and VSHAM groups. In the urethra, gene expression levels of collagen I, III, and elastin were all significantly greater in the cell-injection groups than in the VSHAM group. Collagen I, III, and elastin protein expression of the urethra did not show a consistent trend between cell-injection groups and the VSHAM group. CONCLUSIONS: Human iPSC-derived pSMCs transplantation appears to be associated with improved contractile function of the surgically injured vagina in a rat model. This is accompanied by changes in extracellular protein expression the vagina and urethra. These observations support further efforts in the translation of pSMCs into a treatment for regenerating the surgically injured vagina in women who suffer recurrent prolapse after surgery.

A global bibliometric and visual analysis of research on premature ovarian failure: Based on the perspective of stem cells.

Premature ovarian failure (POF), a condition influenced by genetic and immune factors, remains incurable despite years of intensive research and significant efforts. This persisting challenge underscores the urgency to address this escalating health concern. Fortunately, stem cell regenerative medicine has emerged as a promising avenue for developing therapeutic strategies and innovative treatments for POF. Bibliometric analysis, renowned for its objectivity, systematic approach, and comprehensive coverage of a given field, has yet to be applied to the study of stem cell research in POF. This study used CiteSpace software to assess contributions and co-occurrence relationships among various countries/regions, institutes, journals, and authors. This approach also allowed us to identify research hotspots and promising future trends within this field. Additionally, we generated visualizing maps utilizing the Web of Science Core Collection (WOSCC) and PubMed publications. By providing valuable information and references, we aim to enhance the understanding of the challenges involved in translating stem cell regeneration into clinical therapeutic potential for POF. Furthermore, our analysis and findings guide researchers and clinicians, facilitating future collaborative research and clinical intervention efforts.

Wrapping stem cells with wireless electrical nanopatches for traumatic brain injury therapy.

Electrical stimulation holds promise for enhancing neuronal differentiation of neural stem cells to treat traumatic brain injury. However, once the stem cells leave the stimulating material and migrate post transplantation, electrical stimulation on them is diminished. Here, we wrap the stem cells with wireless electrical nanopatches, the conductive graphene nanosheets. Under electromagnetic induction, electrical stimulation can thus be applied in-situ to individual nanopatch-wrapped stem cells on demand, stimulating their neuronal differentiation through a MAPK/ERK signaling pathway. Consequently, 41% of the nanopatch-wrapped stem cells differentiate into functional neurons in 5 days, as opposed to only 16.3% of the unwrapped ones. The brain injury male mice implanted with the nanopatch-wrapped stem cells and exposed to a rotating magnetic field 30 min/day exhibit significant recovery of brain tissues, behaviors, and cognitions, within 28 days. This study opens up an avenue to individualized electrical stimulation of transplanted stem cells for treating neurodegenerative diseases.

Adipose-derived stem cells transplantation improves survival and alleviates contraction of skin grafts via promoting macrophages M2 polarization.

BACKGROUND: Full-thickness skin grafts are widely used in plastic and reconstructive surgery. The main limitation of skin grafting is the poor textural durability and associated contracture, which often needs further corrective surgery. Excessive inflammation is the main reason for skin graft contractions, which involve overactivation of myofibroblasts. These problems have prompted the development of new therapeutic approaches, including macrophage polarization modulation and stem cell-based therapies. Currently, adipose-derived stem cells (ASCs) have shown promise in promoting skin grafts survival and regulating macrophage phenotypes. However, the roles of ASCs on macrophages in decreasing skin grafts contraction remain unknown. MATERIALS AND METHODS: Rat adipose-derived stem cells (rASCs) were isolated from rat inguinal adipose tissues. Full-thickness skin graft model was constructed on male rats divided into control group and rASCs treatment group. Skin graft was assessed for concentration, elasticity modulus and stiffness. Rat bone marrow-derived macrophages (rBMDMs) were isolated from rat femurs, and subsequent RT-qPCR and coculture assays were carried out to explore the cellular mechanisms. Immunohistochemical and immunofluorescence staining were used to verify mechanisms in vivo. RESULTS: In vivo results showed that after injection of ASCs, improved texture, increased survival and inhibited contraction of skin grafts were seen. Vascularization was also improved as illustrated by laser perfusion image and vascular endothelial growth factor (VEGF) concentration. Histological analysis revealed that ASCs injection significantly reduced expression of pro-inflammatory cytokines (TNF-a, IL-1ß) and increased expression of anti-inflammatory (IL-10) and pro-healing cytokines (IGF-1). At cellular level, after co-culturing with rASCs, rat bone marrow derived macrophages (rBMDMs) favored M2 polarization even under inflammatory stimulus. CONCLUSION: ASCs treatment enhanced vascularization via angiogenic cytokines secretion and alleviated inflammatory environment in skin grafts by driving M2 macrophages polarization, which improved survival and decreased skin grafts contraction. Our work showed that ASCs transplantation can be harnessed to enhance therapeutic efficacy of skin grafting in cutaneous defects treatment.

Stem Cell Therapy for Wound Healing in Ischemic Limbs: Is It Effective?

Critical limb ischemia is an important clinical entity due to its association with increased morbidity and mortality. The mortality and amputation-free survival remains poor especially in those where revascularization is not an option. Recently, the role of cellular therapy has emerged as a promising therapeutic measure that may aid in wound healing and revascularization and improve functional outcomes.

Examining the potentials of stem cell therapy in reducing the burden of selected non-communicable diseases in Africa.

Stem cell therapy (SCT) is a promising solution for addressing health challenges in Africa, particularly non-communicable diseases (NCDs). With their regenerative potential, stem cells have the inherent capacity to differentiate into numerous cell types for tissue repair. Despite infrastructural, ethical, and legal challenges, SCT holds immense promise for managing chronic illnesses and deep-seated tissue injuries. The rising prevalence of NCDs in Africa highlights the need for innovative strategies and treatment options. SCT offers hope in combating conditions like burns, osteoarthritis, diabetes, Alzheimer's disease, stroke, heart failure and cancer, potentially reducing the burden of NCDs on the continent. Despite SCT's opportunities in Africa, there are significant obstacles. However, published research on SCT in Africa is scarce, but recent initiatives such as the Basic School on Neural Stem Cells (NSC) express interest in developing NSC research in Africa. SCT research in African regions, notably on neurogenesis, demonstrates a concentration on studying neurological processes in indigenous settings. While progress has been made in South Africa and Nigeria, issues such as brain drain and impediments to innovation remain. Clinical trials have investigated the efficacy of stem cell treatments, emphasising both potential benefits and limitations in implementing these therapies efficiently. Financing research, developing regulatory frameworks, and resolving affordability concerns are critical steps toward realizing the potential of stem cell treatment in Africa.

Local Injection of Stem Cells Can Be a Potential Strategy to Improve Bladder Dysfunction after Outlet Obstruction in Rats.

This study investigates whether hAFSCs can improve bladder function in partial bladder outlet obstruction (pBOO) rats by targeting specific cellular pathways. Thirty-six female rats were divided into sham and pBOO groups with and without hAFSCs single injection into the bladder wall. Cystometry, inflammation/hypoxia, collagen/fibrosis/gap junction proteins, and smooth muscle myosin/muscarinic receptors were examined at 2 and 6 weeks after pBOO or sham operation. In pBOO bladders, significant increases in peak voiding pressure and residual volume stimulated a significant upregulation of inflammatory and hypoxic factors, TGF-ß1 and Smad2/3. Collagen deposition proteins, collagen 1 and 3, were significantly increased, but bladder fibrosis markers, caveolin 1 and 3, were significantly decreased. Gap junction intercellular communication protein, connexin 43, was significantly increased, but the number of caveolae was significantly decreased. Markers for the smooth muscle phenotype, myosin heavy chain 11 and guanylate-dependent protein kinase, as well as M2 muscarinic receptors, were significantly increased in cultured detrusor cells. However, hAFSCs treatment could significantly ameliorate bladder dysfunction by inactivating the TGFß-Smad signaling pathway, reducing collagen deposition, disrupting gap junctional intercellular communication, and modifying the expressions of smooth muscle myosin and caveolae/caveolin proteins. The results support the potential value of hAFSCs-based treatment of bladder dysfunction in BOO patients.

Limbal graft transplantation: a rare implementation in pediatric limbal stem cell deficiency.

PURPOSE: To evaluate limbal graft transplantation success in pediatric patients with chemical injury-induced limbal stem cell deficiency (LSCD) using the 'LSCD Working Group' staging system. METHODS: Medical records of 11 eyes of 11 children who underwent limbal graft transplantation (limbal autograft/limbal allograft) were included. Surgical success was defined as improvement in the post-operative 1st year LSCD stage. RESULTS: The mean age was 12 ± 5 (4-17) years. Causative agent was alkaline in 4(36.4%) and acid in 3(27.2%) patients. Limbal autograft was performed in 9 (81.8%) eyes with unilateral LSCD, and allograft transplantation was performed in 2 (18.2%) eyes with bilateral LSCD. The mean follow-up time was 33.89 ± 30.73 (12-102.33) months. The overall limbal graft transplantation success rate was 72.7%. Among 9 patients who receive limbal autograft, 8 had improvement in post-operative LSCD stage, 1 had stable LSCD stage. Of the 2 patients who receive limbal allograft, post-operative LSCD stage remained the same in 1 and worsened in 1 patient. The mean time between injury and the surgery was 30.47 ± 30.08 (7-108.47) months. Penetrating keratoplasty was performed in 3 (27.2%) of 11 patients following limbal graft transplantation. CONCLUSION: Management of LSCD in children is challenging and appears to be somewhat different from that of adults. Limited data in the literature indicate that cultivated or simple limbal epithelial transplantations (CLET/SLET) are primarily preferred in children. Although the tendency to take small tissue from the healthy eye is noteworthy, conventional limbal allograft and autograft transplantations also show promising results without any further complications in at least 1 year follow-up period.

[Progress in gene-modified stem cell therapy for penile erectile dysfunction].

Erectile dysfunction (ED) is a common disorder in men and lacks effective treatment. Stem cell (SC) possess the potential in self-renewal and multi-directional differentiation, and secrete a variety of active substances. Stem cell therapy, as a promising option for the treatment of ED, is a focus in regenerative medicine research. However, the effect of stem cell therapy alone on ED is limited due to the complexity of the condition and the limitations of SC. Gene modification can enhance the performance of SC in multiple aspects and play the role of targeted genes, and therefore can better improve ED and its related pathological changes than SC therapy alone. In recent years, gene-modified stem cell therapy has become a hotspot in andrological research. This review summarizes the advances in the studies of gene-modified SC in the treatment of ED, aiming to provide some ideas for further research.

Amelioration of Photoreceptor Degeneration by Intravitreal Transplantation of Retinal Progenitor Cells in Rats.

Photoreceptor degeneration is a major cause of untreatable blindness worldwide and has recently been targeted by emerging technologies, including cell- and gene-based therapies. Cell types of neural lineage have shown promise for replacing either photoreceptors or retinal pigment epithelial cells following delivery to the subretinal space, while cells of bone marrow lineage have been tested for retinal trophic effects following delivery to the vitreous cavity. Here we explore an alternate approach in which cells from the immature neural retinal are delivered to the vitreous cavity with the goal of providing trophic support for degenerating photoreceptors. Rat and human retinal progenitor cells were transplanted to the vitreous of rats with a well-studied photoreceptor dystrophy, resulting in substantial anatomical preservation and functional rescue of vision. This work provides scientific proof-of-principle for a novel therapeutic approach to photoreceptor degeneration that is currently being evaluated in clinical trials.

Cellular heterogeneity of pluripotent stem cell-derived cardiomyocyte grafts is mechanistically linked to treatable arrhythmias.

Preclinical data have confirmed that human pluripotent stem cell-derived cardiomyocytes (PSC-CMs) can remuscularize the injured or diseased heart, with several clinical trials now in planning or recruitment stages. However, because ventricular arrhythmias represent a complication following engraftment of intramyocardially injected PSC-CMs, it is necessary to provide treatment strategies to control or prevent engraftment arrhythmias (EAs). Here, we show in a porcine model of myocardial infarction and PSC-CM transplantation that EAs are mechanistically linked to cellular heterogeneity in the input PSC-CM and resultant graft. Specifically, we identify atrial and pacemaker-like cardiomyocytes as culprit arrhythmogenic subpopulations. Two unique surface marker signatures, signal regulatory protein α (SIRPA)+CD90-CD200+ and SIRPA+CD90-CD200-, identify arrhythmogenic and non-arrhythmogenic cardiomyocytes, respectively. Our data suggest that modifications to current PSC-CM-production and/or PSC-CM-selection protocols could potentially prevent EAs. We further show that pharmacologic and interventional anti-arrhythmic strategies can control and potentially abolish these arrhythmias.

Stem cell-based therapeutic potential in female ovarian aging and infertility.

Premature ovarian insufficiency (POI) is defined as onset of menopause characterized by amenorrhea, hypergonadotropism, and hypoestrogenism, before the age of 40 years. The POI is increasing, which seriously affects the quality of patients' life. Due to its diversity of pathogenic factors, complex pathogenesis and limited treatment methods, the search for finding effective treatment of POI has become a hotspot. Stem cells are characterized by the ability of self-renewal and differentiation and play an important role in the regeneration of injured tissues, which is therapy is expected to be used in the treatment of POI. The aim of this review is to summarize the pathogenic mechanisms and the research progress of POI treatment with stem cells from different sources.

The application of extracorporeal shock wave therapy on stem cells therapy to treat various diseases.

In the last ten years, stem cell (SC) therapy has been extensively used to treat a range of conditions such as degenerative illnesses, ischemia-related organ dysfunction, diabetes, and neurological disorders. However, the clinical application of these therapies is limited due to the poor survival and differentiation potential of stem cells (SCs). Extracorporeal shock wave therapy (ESWT), as a non-invasive therapy, has shown great application potential in enhancing the proliferation, differentiation, migration, and recruitment of stem cells, offering new possibilities for utilizing ESWT in conjunction with stem cells for the treatment of different systemic conditions. The review provides a detailed overview of the advances in using ESWT with SCs to treat musculoskeletal, cardiovascular, genitourinary, and nervous system conditions, suggesting that ESWT is a promising strategy for enhancing the efficacy of SC therapy for various diseases.

Xenogenous implanted dental follicle stem cells promote periodontal regeneration through inducing the N2 phenotype of neutrophils.

BACKGROUND: Periodontal tissue loss is the main reason for tooth mobility and loss caused by periodontal disease. Dental follicle stem cells (DFSCs) have significant therapeutic potential in periodontal regeneration, which maybe mainly depends on their potent immunomodulatory capacity. Consequently, this study aims to elucidate the impact of implanted xenogenous DFSCs on innate immune responses during early and late stages in the periodontal defect repair period. METHODS: To trace and investigate the immunomodulation mechanisms of DFSCs in vivo, DFSCs were engineered (E-DFSCs) using lentiviral vectors expressing CD63-enhanced green fluorescent protein (CD63-EGFP) and ß-Actin-mCherry protein (ACTB-mCherry) to exhibit green and red fluorescence. The biological characteristics and functions of E-DFSCs were verified by proliferation, differentiation, and co-culture experiments in vitro. In vivo, the periodontal regeneration capacity of E-DFSCs was detected by implantation of murine periodontal defect model, and the response of innate immune cells was detected at the 1st, 3rd, and 5th days (early stage) and 4th week (late stage) after implantation. RESULTS: In vitro assessments showed that E-DFSCs retain similar properties to their non-engineered counterparts but exhibit enhanced macrophage immunomodulation capability. In mice models, four-week micro-CT and histological evaluations indicated that E-DFSCs have equivalent efficiency to DFSCs in periodontal defect regeneration. At the early stage of repair in mice periodontal defect, fluorescence tracking showed that implanted E-DFSCs might primarily activate endogenous cells through direct contact and indirect actions, and most of these cells are myeloperoxidase-positive neutrophils. Additionally, compared with the control group, the neutrophilic infiltration and conversion of N2-type were significantly increased in the E-DFSC group. At the late stage of defect regeneration, more M2-type macrophages, fewer TRAP + osteoclasts, and an upregulated OPG/RANKL ratio were detected in the E-DFSC group compared to the control group, which indicated that immune balance tilts towards healing and bone formation. CONCLUSION: The xenogenous implanted DFSCs can induce the N2 phenotype of neutrophils in the early stage, which can activate the innate immune mechanism of the host to promote periodontal tissue regeneration.

Challenges and perspectives of heart repair with pluripotent stem cell-derived cardiomyocytes.

Here we aim at providing a concise but comprehensive overview of the perspectives and challenges of heart repair with pluripotent stem cell-derived cardiomyocytes. This Review comes at a time when consensus has been reached about the lack of relevant proliferative capacity of adult mammalian cardiomyocytes and the lack of new heart muscle formation with autologous cell sources. While alternatives to cell-based approaches will be shortly summarized, the focus lies on pluripotent stem cell-derived cardiomyocyte repair, which entered first clinical trials just 2 years ago. In the view of the authors, these early trials are important but have to be viewed as early proof-of-concept trials in humans that will hopefully provide first answers on feasibility, safety and the survival of allogeneic pluripotent stem cell-derived cardiomyocyte in the human heart. Better approaches have to be developed to make this approach clinically applicable.