Stem cells: past, present, and future

Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOR pathway

JOURNAL/nrgr/04.03/01300535-202511000-00028/figure1/v/2024-12-20T164640Z/r/image-tiff Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells, and can thus be used as substitutes for stem cells in stem cell therapy, thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived treatments. This lays a foundation for the development of potentially potent new treatment modalities for ischemic stroke. However, the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear, presenting challenges for clinical translation. To promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside, we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic stroke. We found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal apoptosis. The human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase, mammalian target of rapamycin, and protein kinase B, and these effects were reversed by treatment with a phosphoinositide 3-kinase inhibitor. These findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway. Finally, we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety profile. Therefore, human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

Single-cell Raman spectroscopy as a novel platform for unveiling the heterogeneity of mesenchymal stem cells

Despite the significant potential of mesenchymal stem cells (MSC) therapy in clinical settings, challenges persist regarding the efficient detection of consistency and uniformity of MSC populations. Raman spectroscopy is a fast, convenient, and nondestructive technique to acquire molecular properties of biomolecules across laboratory and mass-production settings. Here we utilized Raman spectroscopy to evaluate the heterogeneity of primary MSC from varying donors, passages, and distinct culture conditions, and compared its effectiveness with conventional techniques such as flow cytometry. Although these MSC exhibited insignificant differences in morphology and surface markers in flow cytometry analysis, they could be distinctly clustered into different populations by Raman spectroscopy and the subsequent machine learning using linear discriminant analysis. Principal component analysis demonstrated limited efficiency in clustering Raman data from diverse sources, which could be enhanced through combination with support vector machine or deterministic finite automation. These findings highlight the sensitivity of Raman spectroscopy in detecting subtle differences. Moreover, the analysis of characteristic Raman peaks attributed to cellular biomolecules in MSC from passages 2 (P2) to P10 revealed a gradual decrease in the levels of nucleic acids, lipids, and proteins with increasing passages, and a significant increase in carotenoids from P8. These results suggest the potential use of Raman spectroscopy to assess cellular biochemical characteristics such as aging, with carotenoids emerging as a potential marker of cell aging. In conclusion, Raman spectroscopy demonstrates the ability to rapidly and non-invasively detect cellular heterogeneity and biochemical status, offering significant potential for quality control in stem cell therapy.

Cell and gene therapeutic approaches in non-alcoholic fatty liver disease

Non-Alcoholic Fatty Liver Disease (NAFLD) refers to a range of conditions marked by the buildup of triglycerides in liver cells, accompanied by inflammation, which contributes to liver damage, clinical symptoms, and histopathological alterations. Multiple molecular pathways contribute to NAFLD pathogenesis, including immune dysregulation, endoplasmic reticulum stress, and tissue injury. Both the innate and adaptive immune systems play crucial roles in disease progression, with intricate crosstalk between liver and immune cells driving NAFLD development. Among emerging therapeutic strategies, cell and gene-based therapies have shown promise. This study reviews the pathophysiological mechanisms of NAFLD and explores the therapeutic potential of cell-based interventions, highlighting their immunomodulatory effects, inhibition of hepatic stellate cells, promotion of hepatocyte regeneration, and potential for hepatocyte differentiation. Additionally, we examine gene delivery vectors designed to target NAFLD, focusing on their role in engineering hepatocytes through gene addition or editing to enhance therapeutic efficacy.

PCL-fibrin-alginate hydrogel based cell co-culture system for improving angiogenesis and immune modulation in limb ischemia

Stem cell therapy has demonstrated promise in regenerative medicine due to their ability to differentiate into various cell types and secrete growth factors. However, challenges such as poor survival rate of transplanted cells under ischemic and immune conditions limit its effectiveness. To address these issues, we developed a polycaprolactone (PCL)-fibrin-alginate matrix hydrogel, which combines adipose-derived stem cells and human umbilical vein endothelial cells with a PCL fiber, encapsulated within fibrin and alginate hydrogel to enhance cell survival, proliferation, and immune modulation. This structure offers protection to the encapsulated cells, supports angiogenesis, and modulates the immune response, significantly improving therapeutic outcomes in a mouse model of hindlimb ischemia. Our in vitro and in vivo results demonstrate the scaffold's ability to support cell viability, promote angiogenesis, and modulate inflammatory responses, indicating its potential as a promising platform for ischemic tissue repair and regenerative medicine. This innovative approach to cell-based therapy highlights the importance of scaffold design in enhancing the therapeutic efficacy of stem cell treatments for ischemic diseases.

Evaluating the efficacy of stem cells in treating severe dry eye disease

Dry eye disease (DED) is a multifactorial disorder that disturbs ocular surface equilibrium, considerably diminishing quality of life. Present therapies only offer symptomatic alleviation. Stem cell treatment, especially mesenchymal stem cells (MSCs), has surfaced as a viable approach for tissue regeneration and immunological regulation in DED. Preclinical and early clinical investigations indicate that MSCs can improve lacrimal gland functionality, diminish inflammation, and facilitate corneal regeneration. Nonetheless, obstacles persist in enhancing MSC viability, determining the optimal MSC source, and guaranteeing sustained therapeutic effectiveness. Additional extensive randomized clinical trials are required to confirm the efficacy of MSC-based therapies for severe DED.

Cornua cervi degelatinatum inhibits breast cancer stem-like cell properties and metastasis via miR-148a-3p-mediated TGF-β/Smad2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cornua cervi degelatinatum (CCD) is formed by removing the gelatinous substance from deer antlers according to traditional methods. It was first recorded in the Shennong's Classic of Materia Medica and has been included in the Pharmacopoeia of the People's Republic of China. It is commonly used in clinical practice for the treatment of diseases such as cancer and infertility.

AIM OF THE STUDY

This study aims to investigate the impact of CCD aqueous extract on the proliferation and stemness of breast cancer (BC) cells, with an emphasis on its regulation of miR-148a-3p expression and associated molecular pathways.

MATERIALS AND METHODS

Breast cancer cells were treated with various concentrations of CCD to assess its effects on cancer stem cell (CSC) features, epithelial-mesenchymal transition (EMT) markers, and overall plasticity. The UALCAN platform was utilized to analyze the relationship between miR-148a-3p and Smad2 expression. Functional experiments involving miR-148a-3p overexpression were performed to elucidate CCD's modulatory effects on the TGF-β/Smad2 pathway. Furthermore, molecular docking analysis was conducted to predict the binding affinity of CCD's active components to Smad2.

RESULTS

The CCD aqueous extract significantly reduced BC cell viability in vitro and dose-dependently suppressed the expression of stemness- and EMT-related proteins. Bioinformatics analysis and luciferase reporter assays validated miR-148a-3p as a direct regulator of Smad2, inhibiting the TGF-β/Smad2 signaling pathway. Molecular docking revealed strong binding interactions between CCD's active components and Smad2.

CONCLUSIONS

CCD exhibits anti-BC effects by working synergistically with miR-148a-3p to inhibit the TGF-β/Smad2 pathway, thereby reducing BC stemness and EMT progression. These findings provide valuable insights into the molecular mechanisms underlying CCD's therapeutic potential in BC treatment.

Advancing toward a curative frontier: an updated narrative review on stem-cell therapy in pediatric type 1 diabetes

BACKGROUND

Type 1 diabetes (T1D) is a chronic autoimmune disease primarily diagnosed in childhood, characterized by pancreatic β-cell destruction, severe insulin deficiency, and hyperglycemia. Current treatments, including insulin therapy and glucose-lowering medications, manage the condition but fall short of offering a cure. In this review we explore the potential of stem-cell therapy as a transformative and curative approach for T1D, focusing on its promise in regenerating β-cells and addressing challenges specific to the pediatric population.

DATA SOURCES

A comprehensive review of the literature was conducted to evaluate stem-cell types: embryonic, perinatal, adult, induced pluripotent and cancer stem cells, and their role in T1D treatment. Particular emphasis was placed on methods for β-cell differentiation, advancements in autologous and allogeneic stem-cell transplantation and emerging strategies to overcome safety, efficacy, and economic barriers. Challenges such as immune rejection, tumorigenicity, and cost-effectiveness were analyzed, alongside novel solutions like immune-shielding and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 (Cas9) technology.

RESULTS

Stem-cell therapy presents a promising avenue for curing T1D, offering potential for β-cell regeneration and reduced dependence on exogenous insulin. However, challenges such as delayed β-cell functionality, immune responses, tumor risks, and high costs hinder widespread application.

CONCLUSIONS

Advancements in personalized medicine, immune-shielding strategies, and cost reduction may pave the way for clinical success, especially in pediatric populations. Further research addressing these barriers is essential to establish stem-cell therapy as a viable and equitable treatment option.

Repair effect of adipose-derived mesenchymal stem cell-conditioned medium on cyclophosphamide-induced ovarian injury in mice

The chemotherapeutic drug cyclophosphamide (CTX) may damage the ovarian tissue of females and induce premature ovarian insufficiency (POI). This study aimed to investigate the therapeutic effect of adipose-derived mesenchymal stem cell-conditioned medium (ADSC-CM) on CTX-induced POI mice, and to provide new support for the clinical use of cell-free therapy for POI. Female mice were treated with CTX intraperitoneal injection for 2 weeks, followed by ADSCs or ADSC-CM by intravenous injection for 2 weeks. At the end of the experiment, various parameters were assessed, including ovarian interstitial fibrosis, cell proliferation, follicular count, the levels of follicle-stimulating hormone (FSH) and estradiol (E2), and the expression of gonadal hormone receptor. Additionally, we assessed the levels of oxidative stress, apoptosis, and apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) signaling pathway-related proteins and genes in ovarian tissue. The results showed that ADSCs or ADSC-CM treatment reduced ovarian interstitial fibrosis, promoted the proliferation of cells in the follicles, and increased the number of follicles and ovarian function. In addition, ADSCs and ADSC-CM also reduced the levels of ovarian oxidative stress, decreased the apoptosis of granulosa cells (GCs), and inhibited the activation of ASK1/JNK signaling pathway. In conclusion, our study confirmed that ADSC-CM, like ADSCs, could exert therapeutic effects in POI diseases, and the underlying mechanism may be related to the inhibition of oxidative stress-mediated activation of ASK1/JNK signaling pathway. This study has important implications for the development of cell-free therapies for the clinical treatment of POI diseases.

Hydrogels with programmed spatiotemporal mechanical cues for stem cell-assisted bone regeneration

Hydrogels are extensively utilized in stem cell-based tissue regeneration, providing a supportive environment that facilitates cell survival, differentiation, and integration with surrounding tissues. However, designing hydrogels for regenerating hard tissues like bone presents significant challenges. Here, we introduce macroporous hydrogels with spatiotemporally programmed mechanical properties for stem cell-driven bone regeneration. Using liquid-liquid phase separation and interfacial supramolecular self-assembly of protein fibres, the macroporous structure of hydrogels provide ample space to prevent contact inhibition during proliferation. The rigid protein fibre-coated pore shell provides sustained mechanical cues for guiding osteodifferentiation and protecting against mechanical loads. Temporally, the hydrogel exhibits tunable degradation rates that can synchronize with new tissue deposition to some extent. By integrating localized mechanical heterogeneity, macroporous structures, surface chemistry, and regenerative degradability, we demonstrate the efficacy of these stem cell-encapsulated hydrogels in rabbit and porcine models. This marks a substantial advancement in tailoring the mechanical properties of hydrogels for stem cell-assisted tissue regeneration.

Attenuation of Cellular Senescence and Improvement of Osteogenic Differentiation Capacity of Human Liver Stem Cells Using Specific Senomorphic and Senolytic Agents

Expansion of adult stem cells in culture increases the percent of senescent cells, reduces their differentiation capacity and limits their clinical use. Here, we investigated whether treatment with certain senotherapeutic drugs would reduce the accumulation of senescent cells during expansion of human liver stem cells (HLSCs) while maintaining their differentiation capacity. Our results demonstrate that chronic treatment with the senomorphic XJB-5-131 or the senolytics cocktail D + Q reduced the number of senescent cells and significantly reduced the expression of senescence-associated genes and several inflammatory SASP factors in later passage HLSCs. Additionally, treatment with XJB-5-131 and D + Q improved the capacity of HLSCs to undergo osteogenic differentiation following extensive in vitro expansion. Overall, our data demonstrate that treatment with XJB-5-13 or D + Q results in a reduction in the percentage of replication-induced senescent HLSCs and likely other types of adult stem cells and improve the potential therapeutic use of later passage human stem cells.

Immune mediated inflammatory diseases: moving from targeted biologic therapy, stem cell therapy to targeted cell therapy

Despite the advancements in targeted biologic therapy for immune-mediated inflammatory diseases (IMIDs), significant challenges persist, including challenges in drug maintenance, primary and secondary non-responses, and adverse effects. Recent data have strengthened the evidence supporting stem cell therapy as an experimental salvage therapy into a standard treatment option. Recent preclinical and clinical studies suggested that chimeric antigen receptor T cell (CAR-T) therapy, which depleting tissue and bone marrow B cells, may lead to improvement, even inducing long-lasting remissions for patients with IMIDs. In this review, we address the unmet needs of targeted biologic therapy, delineate the critical differences between stem cell transplantation and CAR-T therapy, evaluate the current status of CAR-T therapy for IMIDs and explore its potential and existing limitations.

Cell-based regenerative and rejuvenation strategies for treating neurodegenerative diseases

Neurodegenerative diseases including Alzheimer's and Parkinson's disease are age-related disorders which severely impact quality of life and impose significant societal burdens. Cellular senescence is a critical factor in these disorders, contributing to their onset and progression by promoting permanent cell cycle arrest and reducing cellular function, affecting various types of cells in brain. Recent advancements in regenerative medicine have highlighted "R3" strategies-rejuvenation, regeneration, and replacement-as promising therapeutic approaches for neurodegeneration. This review aims to critically analyze the role of cellular senescence in neurodegenerative diseases and organizes therapeutic approaches within the R3 regenerative medicine paradigm. Specifically, we examine stem cell therapy, direct lineage reprogramming, and partial reprogramming in the context of R3, emphasizing how these interventions mitigate cellular senescence and counteracting aging-related neurodegeneration. Ultimately, this review seeks to provide insights into the complex interplay between cellular senescence and neurodegeneration while highlighting the promise of cell-based regenerative strategies to address these debilitating conditions.

The Protective Effects of MSC-Derived Exosomes Against Chemotherapy-Induced Parotid Gland Cytotoxicity

Background: Fluorouracil (5-FU) is one of the most popular chemotherapeutic agents used in various cancer therapy protocols. Cell-free therapy utilizing exosomes is gaining increased popularity as a safer option due to concerns over potential tumor progression following stem cell therapy. Methods: Parotid glands of albino were treated with a single bone marrow mesenchymal stem cell (BMMSC)-derived exosomes injection (100 μg/kg/dose suspended in 0.2 mL phosphate-buffered saline [PBS]), a single 5-Fu injection (20 mg/kg), and BMMSC-derived exosomes plus 5-FU and compared to control group (daily saline injections). After 30 days, the parotid glands were examined using qualitative histological evaluation, immunohistochemical evaluation using rabbit polyclonal mouse antibody to Ki-67, caspase 3, and iNOS, as well as quantitative real-time polymerase chain reaction (RT-PCR) to evaluate gene expression of TGFβ1, TNF-α, and BCL-2. Results: Histological examination of the parotid gland revealed that BMMSC-derived exosomes restored the glands' architecture and repaired most of the distortion created by 5-FU. Immunohistochemical expression of tumor proliferation and cell death markers were restored to normal levels in the exosome-treated groups that were similar to the control group. Furthermore, BMMSC-derived exosomes reversed the effects of 5-FU on quantitative gene expression levels and showed a significant decrease in TNF-α (p < 0.001) and a significant increase in TGFβ (p < 0.0001) and BCL-2 (p < 0.05) when compared to 5-FU treatment. Conclusion: Within the limitations of the current study, BMMSC-derived exosomes have the potential to counteract the cytotoxic effects of 5-FU on the parotid glands of rats in vivo. Further studies are deemed necessary to simulate clinical scenarios.

Turner syndrome: the promise of fertility via stem cell technology

Turner syndrome (TS) is the most common female sex chromosome disorder, occurring in one out of every 2500 to 3000 live female births. It is caused by the partial or complete loss of one X chromosome. TS is associated with certain physical and medical features, including short stature, estrogen deficiency, delayed puberty, hypothyroidism, and congenital heart defects. The majority of women with TS are infertile as a result of gonadal dysgenesis and primary ovarian insufficiency causing hypergonadotropic hypogonadism. Several reproductive options are available for TS patients. The recent use of stem cells (SCs) was found to constitute a promising new alternative in cases of infertility treatment in this group. SCs are undifferentiated cells that exist in embryos, fetuses, and adults and that produce differentiated cells. They can be used in infertility treatment for ovarian regeneration and oocyte generation. However, additional studies scrutinizing their efficiency and safety are needed. In our review, we present reproductive options that are currently available for women with TS.

Harnessing the potential of tissue engineering to target male infertility: Insights into testicular regeneration

Male infertility is among one of the most challenging health concerns in the world. Traditional therapeutic interventions such as semen and testicular tissue cryopreservation aim to restore or preserve male fertility. However, these methods are subject to limitations that impact their efficacy and are infeasible in cases such as patients who cannot produce mature sperm due to genetic or pathological disorders. Moreover, with the number of cases of prepubertal boys who must undergo gonadotoxic treatments rising, alternatives have been sought for fertility preservation to enhance reproductive rates in vitro and in vivo. Tissue engineering is a promising area that can address aspects that current therapies may not fully encompass through the creation of bioartificial testicular structures or 3D culture systems that allow the establishment of the essential conditions for sperm production. This study aims to first give a brief overview of stem cell therapy in treating male infertility and then go more in-depth regarding the novel methods and procedures based on tissue engineering that have the potential to offer new treatments for infertility caused by testicular disorders and defects.

Quality and Regulatory Requirements for the Manufacture of Master Cell Banks of Clinical Grade iPSCs: The EU and USA Perspectives

The discovery of induced pluripotent stem cells (iPSCs) and protocols for their differentiation into various cell types have revolutionized the field of tissue engineering and regenerative medicine. Developing manufacturing guidelines for safe and GMP-compliant final products has become essential. Allogeneic iPSCs-derived cell therapies are now the preferred manufacturing alternative. This option requires the establishment of clinical-grade master cell banks of iPSCs. This study aimed at reviewing the Quality and Regulatory requirements from the two main authorities in the world-Europe (EMA) and the United States (FDA)-regarding the manufacture of clinical grade master cell banks (iPSCs). The minimum requirements for iPSCs to be used in first-in-human clinical trials were also reviewed, as well as current best practices currently followed by iPSC bank manufacturers for final product characterisation. The methodology used for this work was a review of various sources of information ranging from scientific literature, published guidance documents available on the EMA and FDA websites, GMP and ICH guidelines, and applicable compendial monographs. Manufacturers of iPSCs cell banks looking to qualify them for clinical use are turning to the ICH guidelines and trying to adapt their requirements. Specifically with the impact of the field of iPSC cell banks, the following areas should be subject to guidance and harmonisation: i) expression vectors authorized for iPSC generation; ii) minimum identity testing; iii) minimum purity testing (including adventitious agent testing); and iv) stability testing. Current ICH guidelines for biotechnological/biological products should be extended to cover cell banks used for cell therapies.

Integrin stimulation by collagen I at the progenitor stage accelerates maturation of human iPSC-derived cardiomyocytes

Cell manufacturing challenges have hampered effective preclinical evaluations of mature cardiac cells derived from human-induced pluripotent stem cells (hiPSCs). These challenges mainly stem from standard differentiation methods yielding cardiac cells of an immature phenotype, low cell yields and the need for extended culture for enhanced maturation. Although the intricate relationship between extracellular matrix (ECM) components and integrin expression levels plays a pivotal role during heart development, the impact of differentiation and maturation of cardiac cells on integrin behavior has not been thoroughly studied. This study postulates that cardiac cell maturation is significantly influenced by the timing of integrin stimulation via cell-matrix interactions. We profiled integrin expression levels throughout the differentiation process of cardiac cells and assessed the effects of utilizing defined ECM components as culture substrates on cell adhesion, proliferation, differentiation, and maturation. Our findings reveal that integrins facilitate hiPSC adhesion to ECM coated culture surfaces and underscores dynamic alterations in integrin expression during cardiac cell differentiation. Remarkably, we observed significant enrichments in α2 and β1 collagen integrin levels at the progenitor and differentiated stages. These shifts in collagen integrin levels were associated with enhanced cell seeding efficiency on collagen-type I surfaces and altered population doubling times. The stimulation of collagen integrins at the progenitor stage markedly boosted cardiac cell maturation, demonstrated by a significant (∼3-fold) increase in cardiac troponin I expression compared to the standard method after 15 days of culture. Enhanced maturation levels were further supported by significant increases in sarcomere development, maturation gene expression, morphological features, improved beating potency, and fatty acid metabolism dependency. Cardiac maturation driven by collagen was abrogated upon inhibition of collagen integrins targeted with selective pharmacological blockers, affirming their indispensable role in maturation without affecting cardiac differentiation levels. Our work confirms that stimulating collagen integrins at the progenitor stage is a potential strategy to achieve rapid maturation of hiPSC-derived cardiac cells. STATEMENT OF SIGNIFICANCE: This study offers a novel strategy guided by integrin expression levels for generating hiPSC-CMs with improved maturation features in a short culture period (<16 days). The improvements in cardiac cell maturation were achieved by stimulating collagen type 1 integrin at the progenitor stage. The potential benefits of this method for regenerative cardiac repair will pave the way for the preclinical examination of mature cardiac cells in tissues to advance cell manufacturing and cardiac toxicity studies.

Innovative approaches to boost mesenchymal stem cells efficacy in myocardial infarction therapy

Stem cell-based therapy has emerged as a promising approach for heart repair, potentially regenerating damaged heart tissue and improving outcomes for patients with heart disease. However, the efficacy of stem cell-based therapies remains limited by several challenges, including poor cell survival, low retention rates, poor integration, and limited functional outcomes. This article reviews current enhancement strategies to optimize mesenchymal stem cell therapy for cardiac repair. Key approaches include optimizing cell delivery methods, enhancing cell engraftment, promoting cell functions through genetic and molecular modifications, enhancing the paracrine effects of stem cells, and leveraging biomaterials and tissue engineering techniques. By focusing on these enhancement techniques, the paper highlights innovative approaches that can potentially transform stem cell therapy into a more viable and effective treatment option for cardiac repair. The ongoing research and technological advancements continue to push the boundaries, hoping to make stem cell therapy a mainstream treatment for heart disease.

Cell membrane-derived nanovesicles as extracellular vesicle-mimetics in wound healing

Cell membrane-derived nanovesicles (NVs) have emerged as promising alternatives to extracellular vesicles (EVs) for wound healing applications, addressing the limitations of traditional EVs, which include insufficient targeting capability, low production yield, and limited drug-loading capacity. Through mechanical cell extrusion methods, NVs exhibit superior characteristics, demonstrating enhanced yield, stability, and purity compared to natural EVs. These NVs can be derived from various membrane sources, including single cell types (stem cells, blood cells, immune cells, and bacterial membranes), hybrid cell membranes and cell membranes mixed with liposomes, with each offering unique therapeutic properties. The integration of genetic engineering and surface modifications has further enhanced NV functionality, enabling precise targeting and improved drug delivery capabilities. Recent advances in NV-based therapies have demonstrated their potential across multiple biomedical applications. Although challenges persist in terms of standardization, storage stability, and clinical translation, the combination of natural cell-derived functions with artificial modification potential positions NVs as a promising platform for next-generation therapeutic delivery systems, thereby offering new possibilities in wound healing applications. Finally, we explore the challenges and future prospects of translating NV-based therapeutics into clinical practice, providing insights into the future development of this innovative approach in wound healing and tissue repair.

Stem cell exosomes: new hope and future potential for relieving liver fibrosis

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Importance of dataset design in developing robust U-Net models for label-free cell morphology evaluation

Advances in regenerative medicine highlighted the need for label-free cell image analysis to replace conventional microscopic observation for non-invasive cell quality evaluation. Image-based evaluation provides an efficient, quantitative, and automated approach to cell analysis, but segmentation remains a critical and challenging step. In this study, we investigated how training dataset design influenced the robustness of U-Net models for cell segmentation, focusing on challenges posed by limited data availability in cell culture. Using 2592 image pairs from four cell types representing key morphological categories, we constructed 42 investigation patterns to evaluate the effects of dataset size, dataset content, and morphological diversity on model performance. Our results showed that robust segmentation models could be developed with approximately 10 raw images captured using a 4× objective lens, a much smaller dataset than typically assumed. The dataset content was found to be crucial: training dataset images that captured commonly observed cell patterns yielded more robust models compared to those capturing rare or irregular cell patterns, which often impaired model performance with large deviations. Additionally, including both spindle and round cell morphologies in the training datasets improved model robustness when tested across all four cell types, while datasets restricted to a single morphology type could not achieve robust models. These findings highlight the importance of curating datasets that capture representative yet diverse cell morphologies. By addressing critical questions about dataset design, this study provides actionable guidance for the effective use of deep learning-based cell segmentation models in manufacturing and research applications.

From Promise to Practice: Recent Growth in 30 Years of Tissue Engineering Commercialization

This perspective, marking the 30th anniversary of the Tissue Engineering journal, discusses the exciting trends in the global commercialization of tissue engineering technology. Within a historical context, we present an evolution of challenges and a discussion of the last 5 years of global commercial successes and emerging market trends, highlighting the continued expansion of the field in the northeastern United States. This leads to an overview of the last 5 years' progress in clinical trials for tissue-engineered therapeutics, including an analysis of trends in success and failure. Finally, we provide a broad overview of preclinical research and a perspective on where the state-of-the-art lies on the horizon.

Knowledge and attitude of dental school faculties towards stem cell therapies and their applications

Background

Stem cells are characterized by their ability to self-renew and differentiate across multiple lineages. Knowledge about these cells and their potential is an important factor driving people to support their use. Therefore, we aimed to evaluate the knowledge and attitudes regarding stem cell therapies, education, and donation among faculty members of the College of Dentistry at King Saud University, Saudi Arabia.

Methods

A self-completed questionnaire was distributed among the faculty members, in which questions about demographic data, basic knowledge of stem cells as well as attitudes towards education and participation in stem cell-related research, and tissue donation were raised.

Results

A total of 102 participants responded to the questionnaire. Most participants (62.7%) ranked their stem cell knowledge as basic, despite correctly answering most of the knowledge questions. More than half of faculty mentioned a lack of stem cell-related activities in their courses (59.8%), and most showed strong support for including related education in postgraduate programs (71.6%). Noteworthy, 64% of participants reported interest in stem cell research and 74.5% were willing to donate their tissue for research purposes. The mean ranks of knowledge scores were significantly higher in subjects who have related lectures in undergraduate courses (p < 0.05), and those with high interest in research participation and tissue donation (p < 0.0001), and (p < 0.05) respectively. Most participants (>60%) were not aware about the current applications of stem cell research and therapy in Saudi Arabia.

Conclusion

Most participants had an acceptable degree of knowledge about stem cells and showed a positive attitude to their education and participation in research. Additionally, knowledge scores have significantly and positively influenced those attitudes. More effort is required to promote the presence of local facilities for researchers to participate in stem cell-related research. The results of this study can be used as a foundation for evidence-informed policymaking within dental schools and research institutions.

Placental extract augments mesenchymal stem cells in pancreatic tissue regeneration: A new insight into diabetes treatment

BACKGROUND

Although a wide variety of medicinal interventions and lifestyles have been endeavored so far for the treatment of diabetes mellitus, it is still intractable. The current study aimed to examine the effect of mesenchymal stem cells (MSCs) and/or placental extract (PE) on streptozotocin (STZ) induced diabetic rats.

METHODS

Fifty male albino rats were used. Ten of them as negative control (group I) and the remaining forty rats were subjected to diabetes induction using 50 mg/kg STZ then divided into; group II (positive controls), group III (MSCs treated), group IV (PE treated), and group V (MSCs/PE combination treated). After 4 weeks of treatment, animals were sacrificed; blood samples were collected for determination of glycated hemoglobin by HPLC, and serum was separated for determination of glucose spectrophotometrically and insulin by ELISA. Pancreatic tissues were harvested for histopathological examination and pancreatic duodenal homeobox 1 (Pdx1) gene expression by PCR.

RESULTS

The three treated groups showed significant enhancement in glycemic parameters and Pdx1 gene expression compared with positive control group (P < 0.05). Histopathological examination revealed great improvement in the three treated groups where group V showed the best picture and the best glycemic control.

CONCLUSIONS

This study points to the possible role of PE in DM treatment. The MSCs/PE combination had the ability to return all parameters and Pdx1 gene expression to their normal levels. This action could be attributed to MSCs homing into the pancreas and the pancreatic rejuvenation provided by PE contents of growth factors; EGF, HGF, IGF-1 and IGF-II.

Stem Cell-Based Approaches for Spinal Cord Injury: The Promise of iPSCs

Spinal cord injury (SCI) is a life-altering condition that leads to severe neurological deficits and significantly impacts patients' quality of life. Despite advancements in medical care, current treatment options remain largely palliative, with limited ability to promote meaningful functional recovery. Induced pluripotent stem cells (iPSCs) have emerged as a promising avenue for regenerative medicine, offering patient-specific, cell-based therapeutic potential for SCI repair. This review provides a comprehensive overview of recent advancements in iPSC-based approaches for SCI, detailing the strategies used to generate neural cell types, including neural progenitor cells, oligodendrocytes, astrocytes, and microglia, and their roles in promoting neuroprotection and regeneration. Additionally, we examine key preclinical and clinical studies, highlighting functional recovery assessments and discussing both standardized and debated evaluation metrics. Furthermore, we address critical challenges related to safety, tumorigenicity, immune response, survival, integration, and overcoming the inhibitory microenvironment of the injured spinal cord. We also explore emerging approaches in biomaterial scaffolds, gene editing, and rehabilitation strategies that may enhance the clinical applicability of iPSC-based therapies. By addressing these challenges and refining translational strategies, iPSC-based interventions hold significant potential to revolutionize SCI treatment and improve outcomes for affected individuals.

Navigating the ethical terrain: Off-label and experimental treatments in medical case reports

This article explores the ethical considerations surrounding the reporting of off-label and experimental treatments in medical case reports, with a focus on fields such as oncology, psychiatry, and pediatrics. It emphasizes the balance between innovation and evidence-based medicine, highlighting the critical role of case reports in disseminating clinical experiences and advancing medical knowledge. The discussion delves into the ethical framework guiding case reporting, including principles of patient autonomy, informed consent, non-maleficence, beneficence, justice, and transparency. Challenges such as negative outcome reporting, commercial interests, and the balance between innovation and caution are examined. Recommendations for ethical vigilance, the development of comprehensive guidelines, and the role of regulatory bodies are proposed to ensure patient safety and uphold scientific integrity. The article concludes by underscoring the importance of a collaborative effort among clinicians, researchers, ethicists, and regulatory bodies to foster the responsible advancement of medical science while adhering to the highest ethical standards.

Heterogeneous Sox2 transcriptional dynamics mediate pluripotency maintenance in mESCs in response to LIF signaling perturbations

The LIF signaling pathway and its regulation of internal factors like Sox2 is crucial for maintaining self-renewal and pluripotency in mESCs. However, the direct impact of LIF signaling on Sox2 transcriptional dynamics at the single-cell level remains elusive. Here, we employ PP7/PCP-mediated live imaging to analyze the transcriptional dynamics of Sox2 under perturbation of the LIF signaling pathway at single-cell resolution. Removal of the LIF ligand or addition of a JAK inhibitor heterogeneously affects the cell population, reducing the number of Sox2-active cells, rather than completely abolishing Sox2 expression. Moreover, Sox2-active cells under LIF perturbation exhibit significant reductions in mRNA production per cell. This reduction is characterized by decreased size and frequency of transcriptional bursting, resulting in shorter duration of Sox2 activity. Notably, cells with reduced or absent Sox2 expression demonstrate a significant loss in pluripotency, indicating that a reduction in Sox2 transcription (rather than a complete loss) is sufficient to trigger the transition from embryonic to an early differentiated state. In LIF-perturbed cells with Sox2 expression reduced to about 50% of non-perturbed levels, we observe a binary behavior, with cells either retaining or losing pluripotency-associated traits. Lastly, we find Sox2 expression is transcriptionally inherited across cell cycles, with Sox2-active mother cells more likely to reactivate Sox2 after mitosis compared to Sox2-inactive cells. This robust transcriptional memory is observed independent of LIF signaling perturbation. Our findings provide new insights into the transcriptional regulation of Sox2, advancing our understanding of the quantitative thresholds of gene expression required for pluripotency maintenance and highlighting the power of single-cell approaches to unravel dynamic regulatory mechanisms.

Electrospun meshes for abdominal wall hernia repair: Potential and challenges

Surgical meshes are widely used in abdominal wall hernia repairs. However, consensus on mesh treatment remains elusive due to varying repair outcomes, especially with the introduction of new meshes, posing a substantial challenge for surgeons. Addressing these issues requires communicating the features of emerging candidates with a focus on clinical considerations. Electrospinning is a versatile technique for producing meshes with biomechanical architectures that closely mimic the extracellular matrix and enable incorporation of bioactive and therapeutic agents into the interconnective porous network, providing a favorable milieu for tissue integration and remodeling. Although this promising technique has drawn considerable interest in mesh fabrication and functionalization, currently developed electrospun meshes have limitations in meeting clinical requirements for hernia repair. This review summarizes the advantages and limitations of meshes prepared through electrospinning based on biomechanical, biocompatible, and bioactive properties/functions, offering interdisciplinary insights into challenges and future directions toward clinical mesh-aided hernia repair. STATEMENT OF SIGNIFICANCE: Consensus for hernia treatments using surgical meshes remains elusive based on varying repair outcomes, presenting significant challenges for researchers and surgeons. Differences in understanding mesh between specialists, particularly regarding material characteristics and clinical requirements, contribute to this issue. Electrospinning has been increasingly applied in mesh preparation through various approaches and strategies, aiming to improve abdominal wall hernia by restoring mechanical, morphological and functional integrity. However, there is no comprehensive overview of these emerging meshes regarding their features, functions, and clinical potentials, emphasizing the necessity of interdisciplinary discussions on this topic that build upon recent developments in electrospun mesh and provide insights from clinically practical prospectives.

Genetically modified stem cells for osteoporosis: a systematic review and meta-analysis of preclinical studies

OBJECTIVE

Our meta-analysis aims to assess the efficacy of genetically modified stem cell therapy in preclinical osteoporosis models.

METHODS

We executed a thorough literature search across PubMed, Embase, Web of Science, and the Cochrane Library databases from inception to September 15, 2023. We used a random-effect model for pooled analysis of the effect of genetically modified stem cell therapy on animals with osteoporosis. The primary outcomes included bone mineral density (BMD) and bone volume fraction. (BV/TV). All meta-analyses were performed employing the Cochrane Collaboration's Review Manager (version 5.3) in conjunction with Stata 15.0 statistical software.

RESULTS

A total of 2567 articles were reviewed, of which 16 articles met inclusion criteria. Of these, 13 studies evaluated the BMD and 11 studies evaluated BV/TV. Compared to the control group, genetically modified stem cell therapy was associated with significantly improved BMD (standardized mean difference [SMD] = 1.85, 95% Confidence Interval [CI]: 1.06-2.63, P < 0.001, I2 = 69%) and BV/TV (standardized mean difference [SMD] = 2.11, 95% Confidence Interval [CI]: 1.10-3.12, P < 0.001, I2 = 78%).

CONCLUSION

Genetically modified stem cell therapy is a safe and effective method that can significantly improve the BMD and BV/TV in animal models of osteoporosis. These results provide an important basis for future translational clinical studies of genetically modified stem cells.

Endocannabinoid system upregulates the enrichment and differentiation of human iPSC- derived spermatogonial stem cells via CB2R agonism

BACKGROUND

Male factor infertility (MFI) is responsible for 50% of infertility cases and in 15% of the cases sperm is absent due to germ cell aplasia. Human induced pluripotent stem cell (hiPSC)-derived spermatogonial stem cells (hSSCs) could serve as an autologous germ cell source for MFI in patients with an insufficient sperm yield for assisted reproductive technology (ART). The endocannabinoid system (ECS) has been implicated to play a role in mouse embryonic stem cells (mESCs) and the human testicular environment. However, the contribution of the ECS in hiPSCs and hiPSC-derived hSSCs is currently unknown. Here, we aimed to assess whether hiPSCs and hiPSC-derived hSSCs are regulated by components of the ECS and whether manipulation of the ECS could increase the yield of hiPSC-derived SSCs and serve as an autologous cell-based source for treatment of MFI.

METHODS

We reprogrammed human dermal fibroblasts (hDFs) to hiPSCs, induced differentiation of hSSC from hiPSCs and evaluated the presence of ECS ligands (AEA, 2-AG) by LC/MS, receptors (CB1R, CB2R, TRPV1, GPR55) by qPCR, flow cytometry and immunofluorescent labeling. We then examined the efficacy of endogenous and synthetic selective ligands (ACPA, CB65, CSP, ML184) on proliferation of hiPSCs using real-time cell analysis (RTCA) and assessed the effects of on CB2R agonism on hiPSC pluripotency and differentiation to hSSCs.

RESULTS

hiPSCs from hDFs expressed the pluripotency markers OCT4, SOX2, NANOG, SSEA4 and TRA-1-60; and could be differentiated into ID4+, PLZF + hSSCs. hiPSCs and hiPSC-derived hSSCs secreted AEA and 2-AG at 10- 10 - 10- 9 M levels. Broad expression of all ECS receptors was observed in both hiPSCs and hiPSC-derived hSSCs, with a higher CB2R expression in hSSCs in comparison to hiPSCs. CB2R agonist CB65 promoted proliferation and differentiation of hiPSCs to hiPSC-hSSCs in comparison to AEA, 2-AG, ACPA, CSP and ML184. The EC50 of CB65 was determined to be 2.092 × 10- 8 M for support of pluripotency and preservation of stemness on hiPSCs from 78 h. CB65 stimulation at EC50 also increased the yield of ID4 + hSSCs, PLZF + SSPCs and SCP3 + spermatocytes from day 10 to 12.

CONCLUSIONS

We demonstrated here for the first time that stimulation of CB2R results in an increased yield of hiPSCs and hiPSC-derived hSSCs. CB65 is a potent CB2R agonist that can be used to increase the yield of hiPSC-derived hSSCs offering an alternative source of autologous male germ cells for patients with MFI. Increasing the male germ/stem cell pool by CB65 supplementation could be part of the ART-associated protocols in MFI patients with complete germ cell aplasia.

A novel three-dimensional co-culture model for studying exosome-mediated cell interactions in glioblastoma

Three-dimensional(3D) cell culture systems provide a larger space for cell proliferation, which is crucial for simulating cellular behavior and drug responses in the tumor microenvironment. In this study, we developed a novel 3D co-culture system for cell interactions, utilizing a commercialized bioreactor-microcarrier system. Mesenchymal stem cells (MSCs) were extracted via enzymatic digestion, and markers CD105 and CD31 were identified. Cell growth was observed using AO and immunofluorescence staining. No significant differences in Ki67 and GFAP expression were found between 2D and 3D cultures, though the 3D system offered more space for proliferation and reduced contact inhibition. Therefore, this 3D culture system may represent the tumor microenvironment more accurately than 2D cultures and will facilitate the investigation of the characteristics and functions of exosomes derived from this system. Exosomes are nanoscale vesicles that mediate intercellular communication by transferring molecules such as miRNAs between cells. Exosomes from 3D cultures were collected via ultra-high-speed centrifugation and characterized using nano-flow cytometry, transmission electron microscopy, and western blotting for markers CD9, Alix, and TSG101. PKH26 staining revealed peak exosome uptake by tumor cells at 24 h and complete metabolism by 72 h. Exosomes from 3D cultures inhibited GBM cell proliferation, migration, and invasion. Lastly, miRNA sequencing of exosomes was performed. This study emphasizes the importance of creating 3D co-culture systems to advance cancer research and offers a helpful tool for studying the complex cell interaction environment of GBM and other malignancies.

Stem Cells Treatment for Subarachnoid Hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) refers to bleeding in the subarachnoid space, which is a serious neurologic emergency. However, the treatment effects of SAH are limited. In recent years, stem cell (SC) therapy has gradually become a very promising therapeutic method and advanced scientific research area for SAH.

REVIEW SUMMARY

The SCs used for SAH treatment are mainly bone marrow mesenchymal stem cells (BMSCs), umbilical cord mesenchymal stem cells (hUC-MSCs), dental pulp stem cells (DPSCs), neural stem cells (NSCs)/neural progenitor cell (NPC), and endothelial progenitor cell (EPC). The mechanisms mainly included differentiation and migration of SCs for tissue repair; alleviating neuronal apoptosis; anti-inflammatory effects; and blood-brain barrier (BBB) protection. The dosage of SCs was generally 10 6 orders of magnitude. The administration methods included intravenous injection, nasal, occipital foramen magnum, and intraventricular administration. The administration time is generally 1 hour after SAH modeling, but it may be as late as 24 hours or 6 days. Existing studies have confirmed the neuroprotective effect of SCs in the treatment of SAH.

CONCLUSIONS

SC has great potential application value in SAH treatment, a few case reports have provided support for this. However, the relevant research is still insufficient and there is still a lack of clinical research on the SC treatment for SAH to further evaluate the effectiveness and safety before it can go from experiment to clinical application.

Exploring the ncRNA landscape in exosomes: Insights into wound healing mechanisms and therapeutic applications

Exosomal non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have emerged as crucial modulators in cellular signaling, influencing wound healing processes. Stem cell-derived exosomes, which serve as vehicles for these ncRNAs, show remarkable therapeutic potential due to their ability to modulate wound healing stages, from initial inflammation to collagen formation. These ncRNAs act as molecular signals, regulating gene expression and protein synthesis necessary for cellular responses in healing. Wound healing is a complex, staged process involving inflammation, hemostasis, fibroblast proliferation, angiogenesis, and tissue remodeling. Stem cell-derived exosomal ncRNAs enhance these stages by reducing excessive inflammation, promoting anti-inflammatory responses, guiding fibroblast and keratinocyte maturation, enhancing vascularization, and ensuring organized collagen deposition. Their molecular cargo, particularly ncRNAs, specifically targets pathways to aid chronic wound repair and support scarless regeneration. This review delves into the unique composition and signaling roles of Stem cell-derived exosomes and ncRNAs, highlighting their impact across wound healing stages and their potential as innovative therapeutics. Understanding the interaction between exosomal ncRNAs and cellular signaling pathways opens new avenues in regenerative medicine, positioning Stem cell-derived exosomes and their ncRNAs as promising molecular-level interventions in wound healing.

Exploring the Potential of Stem Cells in Modulating Gut Microbiota and Managing Hypertension

Hypertension, commonly known as high blood pressure, is a significant health issue that increases the risk of cardiovascular diseases, stroke, and renal failure. This condition broadly encompasses both primary and secondary forms. Despite extensive research, the underlying mechanisms of systemic arterial hypertension-particularly primary hypertension, which has no identifiable cause and is affected by genetic and lifestyle agents-remain complex and not fully understood. Recent studies indicate that an imbalance in gut microbiota, referred to as dysbiosis, may promote hypertension, affecting blood pressure regulation through metabolites such as short-chain fatty acids and trimethylamine N-oxide. Current antihypertensive medications face limitations, including resistance and adherence issues, highlighting the need for novel therapeutic approaches. Stem cell therapy, an emerging field in regenerative medicine, shows promise in addressing these challenges. Stem cells, with mesenchymal stem cells being a prime example, have regenerative, anti-inflammatory, and immunomodulatory properties. Emerging research indicates that stem cells can modulate gut microbiota, reduce inflammation, and improve vascular health, potentially aiding in blood pressure management. Research has shown the positive impact of stem cells on gut microbiota in various disorders, suggesting their potential therapeutic role in treating hypertension. This review synthesizes the recent studies on the complex interactions between gut microbiota, stem cells, and systemic arterial hypertension. By offering a thorough analysis of the current literature, it highlights key insights, uncovers critical gaps, and identifies emerging trends that will inform and guide future investigations in this rapidly advancing field.

Electrical impedance sensing in stem cell research: Insights, applications, and future directions

The exceptional differentiation abilities of stem cells make them ideal candidates for cell replacement therapies. Considering their great potential, researchers should understand how stem cells interact with other cell types. The production of high-quality differentiated cells is crucial for favorable treatment and makes them an ideal choice for clinical applications. Label-free stem cell monitoring approaches are anticipated to be more effective in this context, as they ensure quality of differentiation while preserving the therapeutic potential. Electric cell-substrate impedance sensing (ECIS) is a nonintrusive technique that enables cell quantification through continuous monitoring of adherent cell behavior using electronic transcellular impedance measurements. This technique also facilitates the study of cell growth, motility, differentiation, drug effects, and cell barrier functions. Therefore, numerous studies have identified ECIS as an effective method for monitoring stem cell quality and differentiation. In this review, we discuss the current understanding of ECIS's achievements in examining cell behaviors and the potential applications of ECIS arrays in preclinical stem cell research. Moreover, we highlight our present knowledge concerning ECIS's contributions in examining cell behaviors and speculate about the future uses of ECIS arrays in preclinical stem cell research. This review also aims to stimulate research on electrochemical biosensors for future applications in regenerative medicine.

Intracavernosal mesenchymal stem cell therapy in ischaemic priapism: an experimental study

INTRODUCTION

The most common form of priapism is ischaemic and its prevalence in men has increased in recent years as a result of intracavernosal drug use. Currently, there is no approved specific treatment for ischaemic priapism other than cavernosal aspiration, which can only provide detumescence. This study aims to evaluate the efficacy of intracavernosal mesenchymal stem cell (MSC) therapy in an ischaemic priapism model.

MATERIAL AND METHODS

Thirty male Wistar albino rats were divided into three groups: sham (n = 6), priapism (n = 12) and priapism + MSC treatment (n = 12). The experimental groups were also divided into 1 and 12 h subgroups of ischaemic priapism. The experimental model was created using a vacuum erection device and constrictive tape technique, and intracavernosal MSC were applied immediately after the tape was removed. After 4 weeks, intracavernosal pressures (ICPs) and systemic mean arterial pressure (MAP) were measured. Penectomy was then performed to assess histopathological and molecular changes in the rats' penile tissues.

RESULTS

In the ischaemic priapism model, MSC therapy showed significant improvements in peak and mean ICPs and mean ICP/MAP ratio. Histopathological analysis showed significant increases in smooth-muscle/collagen ratio and e-NOS and n-NOS expression. Although there was a decrease in fibrosis, it was not significant. At the molecular level, there were significant decreases in TGF-beta and VEGF mRNA expression, whilst NGF and BDNF mRNA-expression levels showed significant increases with MSC therapy. In terms of ICPs, the therapy showed more significant improvements in short-term priapism. However, when looking at histopathological and molecular parameters, the therapy had positive effects on a wider range of parameters in the long-term priapism.

CONCLUSION

MSC treatment improved cavernosal physiology and had positive effects at the histopathological and molecular level in the ischaemic priapism model.

Assessment of the Therapeutic Effectiveness of Glutathione-Enhanced Mesenchymal Stem Cells in Rat Models of Chronic Bladder Ischemia-Induced Overactive Bladder and Detrusor Underactivity

Overactive bladder (OAB) and detrusor underactivity (DUA) are representative voiding dysfunctions with a chronic nature and limited treatment modalities, and are ideal targets for stem cell therapy. In the present study, we investigated the therapeutic efficacy of human mesenchymal stem cells (MSCs) with a high antioxidant capacity generated by the Primed Fresh OCT4 (PFO) procedure in chronic bladder ischemia (CBI)-induced OAB and DUA rat models. Sixteen-week-old male Sprague-Dawley rats were divided into three groups (sham, OAB or DUA, and stem cell groups; n=10, respectively). CBI was induced by bilateral iliac arterial injury (OAB, 10 times; DUA, 30 times) followed by a 1.25% cholesterol diet for 8 weeks. Seven weeks after injury, rats in the stem cell and other groups were injected with 1╳106 PFO-MSCs and phosphate buffer, respectively. One week later, bladder function was analyzed by awake cystometry and bladders were harvested for histological analysis. CBI with a high-fat diet resulted in atrophy of smooth muscle and increased collagen deposits correlating with reduced detrusor contractility in both rat models. Arterial injury 10 and 30 times induced OAB (increased number of non-voiding contractions and shortened micturition interval) and DUA (prolonged micturition interval and increased residual volume), respectively. Injection of PFO-MSCs with the enhanced glutathione dynamics reversed both functional and histological changes; it restored the contractility, micturition interval, residual volume, and muscle layer, with reduced fibrosis. CBI followed by a high-fat diet with varying degrees of arterial injury induced OAB and DUA in rats. In addition, PFO-MSCs alleviated functional and histological changes in both rat models.

Therapeutic effect of long-interval repeated subcutaneous administration of canine amniotic membrane-derived mesenchymal stem cells in atopic dermatitis mouse model

Atopic dermatitis (AD) is a chronic and inflammatory disease. According to a recent study, administration of canine MSCs is a potential therapy for immunological diseases. However, most related studies involve short-term experiments and acute atopic dermatitis animal models. Thus, studies of repeated subcutaneous injection of canine MSCs for ameliorating long-term inflammatory skin disorders have not yet been established. In this study, we evaluated the effects of long-term canine amniotic mesenchymal stem cells (cAM-MSCs) and calcineurin inhibitors (CNIs) treatments in mouse AD model for up to 8 weeks and compared the differences in therapeutic effect through canine peripheral blood mononuclear cells (PBMCs). Using a mouse model, we validated the therapeutic impact of cAM-MSCs in comparison to pimecrolimus (Pime), the most widely used CNIs, as a therapy for canine AD. Based on our results, we verified that the cAM-MSC treatment group exhibited substantially lower scores for tissue pathologic alterations, inflammatory cytokines, and dermatologic symptoms than the PBS control group. Importantly, compared with Pime, cAM-MSCs were more effective at preventing wound dysfunction and regulating mast cell activity. Additionally, we confirmed that immune modulation proteins (TGF-β1, IDO1, and COX-2) were increased in the cAM-MSCs treatment group. Furthermore, we examined the immunoregulatory effect of cAM-MSCs through the proliferation of T lymphocytes from activated canine PBMCs. As a result, cAM-MSCs suppressed the proliferative capacity of effector T cells from canine PBMCs more effectively than Pime. In conclusion, this study suggested that the cAM-MSCS could be an effective canine treatment for long-term canine AD through regeneration and immunomodulation.

The efficacy of miR-141-3p to facilitate the healing of wounds and prevent scarring in mice by blocking the JNK/ERK pathway via HDAC6 silencing

PURPOSE

Adipose-derived mesenchymal stem cells (ADSCs) exosomes (AD-Exos) are a novel and promising therapeutic approach for skin damage repair. This investigation seeks to assess the potential clinical utility of miR-141-3p found in AD-exos for expediting wound healing.

METHODS

ADSCs were isolated from the wounded patients' tissue and validated via flow cytometry, and the mineralization and adipogenic capabilities of ADSCs were assessed respectively. Additionally, exosomes were isolated and identified. miR-141-3p and HDAC6.protein level were tested. Full-thickness wound models were created on the backs of mice, HE staining, ELISA, and immunohistochemistry were used to assess the influences of AD-exos on wound healing, inflammation, and new blood vessel formation Western blot was to assess the related-protein levels of JNK/ERK pathway. AQ1 Meanwhile, Dual-Luciferase assay confirmed the relationship between miR-141-3p and HDAC6.

RESULTS

The isolated cells highly express surface markers of mesenchymal stem cells and possess the potential for multidirectional differentiation, confirming them to be ADSCs. And miR-141-3p down-regulated but HDAC6 up-regulated in the serum and AD-exos of wounded patients. miR-141-3p could negatively modulate HDAC6. The miR-141-3p in AD-exos accelerated wound healing in mice, mitigated inflammatory responses and scarring in the injured skin tissue, and promoted angiogenesis, moreover, AD-exos could diminish the phosphorylation of JNK and ERK, while HDAC6 overexpressed could weaken these impacts.

CONCLUSION

miR-141-3p in AD-exos can target down regulate HDAC6 expression and inhibit JNK/ERK signaling pathway activation, thereby reducing wound inflammation and promoting angiogenesis and wound healing in mice.

Identification of Meibomian gland stem cell populations and mechanisms of aging

Meibomian glands secrete lipid-rich meibum, which prevents tear evaporation. Aging-related Meibomian gland shrinkage may result in part from stem cell exhaustion and is associated with evaporative dry eye disease, a common condition lacking effective treatment. The identities and niche of Meibomian gland stem cells and the signals controlling their activity are poorly defined. Using snRNA-seq, in vivo lineage tracing, ex vivo live imaging, and genetic studies in mice, we identify markers for stem cell populations that maintain distinct regions of the gland and uncover Hedgehog (Hh) signaling as a key regulator of stem cell proliferation. Consistent with this, we show that human Meibomian gland carcinoma exhibits increased Hh signaling. Aged glands display decreased Hh and EGF signaling, deficient innervation, and loss of collagen I in niche fibroblasts, indicating that alterations in both glandular epithelial cells and their surrounding microenvironment contribute to age-related degeneration. These findings suggest new approaches to treat aging-associated Meibomian gland loss.

Pyroptosis: candidate key targets for mesenchymal stem cell-derived exosomes for the treatment of bone-related diseases

Bone-related diseases impact a large portion of the global population and, due to their high disability rates and limited treatment options, pose significant medical and economic challenges. Mesenchymal stem cells (MSCs) can differentiate into multiple cell types and offer strong regenerative potential, making them promising for treating various diseases. However, issues with the immune response and cell survival limit the effectiveness of cell transplantation. This has led to increased interest in cell-free stem cell therapy, particularly the use of exosomes, which is the most studied form of this approach. Exosomes are extracellular vesicles that contain proteins, lipids, and nucleic acids and play a key role in cell communication and material exchange. Pyroptosis, a form of cell death involved in innate immunity, is also associated with many diseases. Studies have shown that MSC-derived exosomes have therapeutic potential for treating a range of conditions by regulating inflammation and pyroptosis. This study explored the role of MSC-derived exosomes in modulating pyroptosis to improve the treatment of bone-related diseases.

Spatially controlled multicellular differentiation of stem cells using triple factor-releasing metal-organic framework-coated nanoline arrays

Improved in vitro models are needed for regenerative therapy and drug screening. Here, we report on functionally aligned nanoparticle-trapped nanopattern arrays for spatially controlled, precise mesenchymal stem cell differentiation on a single substrate. The arrays comprise nanohole and nanoline arrays fabricated through interference lithography and selectively capture of UiO-67 metal-organic frameworks on nanoline arrays with a 99.8% efficiency using an optimised asymmetric spin-coating method. The UiO-67 metal-organic frameworks contain three osteogenic differentiation factors for sustained release over four weeks. The combination of differentiation factors and patterned array allows for generation of adipocytes, osteoblasts, and adipocyte-osteoblast mixtures on nanohole arrays, nanoline arrays, and at the nanohole-nanoline interface, respectively, with mature osteoblasts exhibiting higher marker expression and mineralisation. The sustained release patterned array holds potential for constructing advanced therapeutic and disease state in vitro cellular models.

Unraveling the function of TSC1-TSC2 complex: implications for stem cell fate

BACKGROUND

Tuberous sclerosis complex is a genetic disorder caused by mutations in the TSC1 or TSC2 genes, affecting multiple systems. These genes produce proteins that regulate mTORC1 activity, essential for cell function and metabolism. While mTOR inhibitors have advanced treatment, maintaining long-term therapeutic success is still challenging. For over 20 years, significant progress has linked TSC1 or TSC2 gene mutations in stem cells to tuberous sclerosis complex symptoms.

METHODS

A comprehensive review was conducted using databases like Web of Science, Google Scholar, PubMed, and Science Direct, with search terms such as "tuberous sclerosis complex," "TSC1," "TSC2," "stem cell," "proliferation," and "differentiation." Relevant literature was thoroughly analyzed and summarized to present an updated analysis of the TSC1-TSC2 complex's role in stem cell fate determination and its implications for tuberous sclerosis complex.

RESULTS

The TSC1-TSC2 complex plays a crucial role in various stem cells, such as neural, germline, nephron progenitor, intestinal, hematopoietic, and mesenchymal stem/stromal cells, primarily through the mTOR signaling pathway.

CONCLUSIONS

This review aims shed light on the role of the TSC1-TSC2 complex in stem cell fate, its impact on health and disease, and potential new treatments for tuberous sclerosis complex.

Constructing a potential HLA haplo-homozygous induced pluripotent stem cell haplobank using data from an umbilical cord blood bank

BACKGROUND

Induced pluripotent stem cells (iPSCs) can differentiate into any type of cell and have potential uses in regenerative medicine for the treatment of many diseases. However, reducing immune rejection is a key problem in the application of iPSCs that can be solved by the development of haplobanks containing specially selected iPSC lines.

METHODS

To study the feasibility of constructing an HLA (human leukocyte antigen)-matched induced pluripotent stem cell haplobank in China, 5421 umbilical cord blood samples were randomly collected from the Umbilical Cord Blood Bank of Zhejiang Province, China. The HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 loci were genotyped using next-generation sequencing. Using HLA genotype data at the high-resolution level, the number of HLA homozygous donors needed to cover a certain percentage of the Chinese population and the feasibility of constructing a high-matching iPSC haplobank were estimated.

RESULTS

Thirteen HLA-A, -B, and -DRB1 and 11 HLA-A, -B, -C, -DRB1, and -DQB1 haplotype homozygotes were observed among the stored umbilical CB units which were as HLA zero-mismatched iPSC donors cumulatively matched 37.01% and 32.99% of 5421 potential patients respectively. The analysis showed that 100 distinct HLA-A, -B, and -DRB1 and HLA-A, -B, -C, -DRB1, and -DQB1 homozygous haplotypes would cover 72.74% and 67.87% of Chinese populations, respectively, and 600 HLA-A, -B, -C, -DRB1, and -DQB1 homozygous haplotypes would cover more than 90% of Chinese populations. PCA (principal component analysis) of published HLA data from different populations revealed that the frequency of these haplotypes in Asian populations is different from those in European populations.

CONCLUSION

The results suggested that at least some HLA-homozygous iPSC lines developed from Chinese individuals will not only be useful for covering the Chinese population but will also cover other Asian populations. A high-matching iPSC haplobank generated from umbilical CB units may be an economical and effective option in an allogeneic model of iPSC therapy.

Injectable acellular matrix microgel assembly with stem cell recruitment and chondrogenic differentiation functions promotes microfracture-based articular cartilage regeneration

Articular cartilage repair and regeneration is still a significant challenge despite years of research. Although microfracture techniques are commonly used in clinical practice, the newborn cartilage is usually fibrocartilage rather than hyaline cartilage, which is mainly attributed to the inadequate microenvironment for effectively recruiting, anchoring, and inducing bone marrow mesenchymal stem cells (BMSCs) to differentiate into hyaline cartilage. This paper introduces a novel cartilage acellular matrix (CACM) microgel assembly with excellent microporosity, injectability, tissue adhesion, BMSCs recruitment and chondrogenic differentiation capabilities to improve the microfracture-based articular cartilage regeneration. Specifically, the sustained release of simvastatin (SIM) from the SIM@CACM microgel assembly efficiently recruits BMSCs in the early stage of cartilage regeneration, while the abundant interconnected micropores and high specific area assure the quick adhesion, proliferation and infiltration of BMSCs. Additionally, the active factors within the CACM matrix, appropriate mechanical properties of the microgel assembly, and excellent tissue adhesion provide a conductive environment for the continuous chondrogenic differentiation of BMSCs into hyaline cartilage. Owing to the synergistic effect of the above-mentioned factors, good articular cartilage repair and regeneration is achieved.

Therapeutic effect of low-dose BMSCs-Loaded 3D microscaffold on early osteonecrosis of the femoral head

The early treatment of Osteonecrosis of Femoral Head (ONFH) remains a clinical challenge. Conventional Bone Marrow Mesenchymal Stem Cell (BMSC) injection methods often result in unsatisfactory outcomes due to mechanical cell damage, low cell survival and retention rates, inadequate cell matrix accumulation, and poor intercellular interaction. In this study, we employed a novel cell carrier material termed "3D Microscaffold" to deliver BMSCs, addressing these issues and enhancing the therapeutic effects of cell therapy for ONFH. We injected 3D microscaffold loaded with low-dose BMSCs or free high-dose BMSCs into the femoral heads of ONFH rats and assessed therapeutic effects using imaging, serology, histology, and immunohistochemistry. To understand the mechanism of efficacy, we established a co-culture model of human osteoblasts and BMSCs, followed by cell proliferation and activity detection, flow cytometry analysis, Quantitative RT-PCR, and Western blotting. Additionally, RNA sequencing was performed on femoral head tissues. Results showed that the 3D microscaffold with low-dose BMSCs had a therapeutic effect comparable to high-dose free BMSCs. Osteoblasts in the 3D microscaffold group exhibited superior phenotypes compared to the non-3D microscaffold group. Furthermore, we have, for the first time, preliminarily validated that the low-dose BMSCs-loaded 3D microscaffolds may promote the repair of femoral head necrosis through the synergistic action of the MAPK and Hippo signaling pathways.

Animal models of Kabuki syndrome and their applicability to novel drug discovery

INTRODUCTION

Kabuki Syndrome (KS) is a rare genetic disorder characterized by distinctive facial features, intellectual disability, and multiple congenital anomalies. It is caused by pathogenic variants in the KMT2D and KDM6A genes. Despite its significant disease burden, there are currently no approved therapies for KS, highlighting the need for advanced research and therapeutic development.

AREAS COVERED

This review examines the use of animal models in KS research, including mice, fish, frogs, and nematodes. These models replicate key mechanistic and clinical aspects of Kabuki Syndrome, facilitating preclinical studies to demonstrate therapeutic efficacy. The literature search focused on identifying studies that utilized these models to investigate the pathophysiology of Kabuki Syndrome and evaluate potential treatments.

EXPERT OPINION

Refining animal models is essential to enhance their relevance to human disease and accelerate the development of effective therapies for Kabuki Syndrome. Insights from these models are invaluable in understanding underlying molecular mechanisms and identifying therapeutic targets. Continued research and collaboration are crucial to translating these findings into clinical practice, offering hope for future treatments.

Synergy between pluripotent stem cell-derived macrophages and self-renewing macrophages: Envisioning a promising avenue for the modelling and cell therapy of infectious diseases

As crucial phagocytes of the innate immune system, macrophages (Mϕs) protect mammalian hosts, maintain tissue homeostasis and influence disease pathogenesis. Nonetheless, Mϕs are susceptible to various pathogens, including bacteria, viruses and parasites, which cause various infectious diseases, necessitating a deeper understanding of pathogen-Mϕ interactions and therapeutic insights. Pluripotent stem cells (PSCs) have been efficiently differentiated into PSC-derived Mϕs (PSCdMϕs) resembling primary Mϕs, advancing the modelling and cell therapy of infectious diseases. However, the mass production of PSCdMϕs, which lack proliferative capacity, relies on large-scale expansions of PSCs, thereby increasing both costs and culture cycles. Notably, Mϕs deficient in the MafB/c-Maf genes have been reported to re-enter the cell cycle with the stimulation of specific growth factor cocktails, turning into self-renewing Mϕs (SRMϕs). This review summarizes the applications of PSCdMϕs in the modelling and cell therapy of infectious diseases and strategies for establishing SRMϕs. Most importantly, we innovatively propose that PSCs can serve as a gene editing platform to creating PSC-derived SRMϕs (termed PSRMϕs), addressing the resistance of Mϕs against genetic manipulation. We discuss the challenges and possible solutions in creating PSRMϕs. In conclusion, this review provides novel insights into the development of physiologically relevant and expandable Mϕ models, highlighting the enormous potential of PSRMϕs as a promising avenue for the modelling and cell therapy of infectious diseases.

Biofabrication Directions in Recapitulating the Immune System-on-a-Chip

Ever since the implementation of microfluidics in the biomedical field, in vitro models have experienced unprecedented progress that has led to a new generation of highly complex miniaturized cell culture platforms, known as Organs-on-a-Chip (OoC). These devices aim to emulate biologically relevant environments, encompassing perfusion and other mechanical and/or biochemical stimuli, to recapitulate key physiological events. While OoCs excel in simulating diverse organ functions, the integration of the immune organs and immune cells, though recent and challenging, is pivotal for a more comprehensive representation of human physiology. This comprehensive review covers the state of the art in the intricate landscape of immune OoC models, shedding light on the pivotal role of biofabrication technologies in bridging the gap between conceptual design and physiological relevance. The multifaceted aspects of immune cell behavior, crosstalk, and immune responses that are aimed to be replicated within microfluidic environments, emphasizing the need for precise biomimicry are explored. Furthermore, the latest breakthroughs and challenges of biofabrication technologies in immune OoC platforms are described, guiding researchers toward a deeper understanding of immune physiology and the development of more accurate and human predictive models for a.o., immune-related disorders, immune development, immune programming, and immune regulation.