CDK8/19 inhibition plays an important role in pancreatic β-cell induction from human iPSCs

Scale up manufacturing approach for production of human induced pluripotent stem cell-derived islets using Vertical Wheel® bioreactors

Advanced protocols show potential for human stem cells (SC)-derived islets generation under planar (2D) alone or three-dimensional (3D) cultures, but show challenges in scalability, cell loss, and batch-to-batch consistency. This study explores Vertical Wheel (VW)® bioreactor suspension technology to differentiate islets from human induced pluripotent stem cells, achieving uniform, transcriptionally mature, and functional SC-islets. A 5x increase in scale from 0.1 L to 0.5 L reactors resulted in a 12-fold (15,005-183,002) increase in islet equivalent count (IEQ) without compromising islet structure. SC-islets show enriched β-cell composition (~63% CPPT+NKX6.1+ISL1+), glucose responsive insulin release (3.9-6.1-fold increase), and reversed diabetes in STZ-treated mice. Single cell RNA sequencing and flowcytometry analysis confirmed transcriptional maturity and functional identity, similar to adult islets. Lastly, harvested SC-islet grafts demonstrate improved islet functionality and mature transcriptomic signatures. Overall, scale-up in VW® bioreactor technology enhances IEQ yield with minimal variability and reduced cell loss, offering a pathway for clinical-grade SC-islet production.

Therapeutic Role of Probiotics Against Environmental-Induced Hepatotoxicity: Mechanisms, Clinical Perspectives, Limitations, and Future

Hepatotoxicity is one of the biggest health challenges, particularly in the context of liver diseases, often aggravated by gut microbiota dysbiosis. The gut-liver axis has been regarded as a key idea in liver health. It indicates that changes in gut flora caused by various hepatotoxicants, including alcoholism, acetaminophen, carbon tetrachloride, and thioacetamide, can affect the balance of the gut's microflora, which may lead to increased dysbiosis and intestinal permeability. As a result, bacterial endotoxins would eventually enter the bloodstream and liver, causing hepatotoxicity and inducing inflammatory reactions. Many treatments, including liver transplantation and modern drugs, can be used to address these issues. However, because of the many side effects of these approaches, scientists and medical experts are still hoping for a therapeutic approach with fewer side effects and more positive results. Thus, probiotics have become well-known as an adjunctive strategy for managing, preventing, or reducing hepatotoxicity in treating liver injury. By altering the gut microbiota, probiotics offer a secure, non-invasive, and economical way to improve liver health in the treatment of hepatotoxicity. Through various mechanisms such as regulation of gut microbiota, reduction of pathogenic overgrowth, suppression of inflammatory mediators, modification of hepatic lipid metabolism, improvement in the performance of the epithelial barrier of the gut, antioxidative effects, and modulation of mucosal immunity, probiotics play their role in the treatment and prevention of hepatotoxicity. This review highlights the mechanistic effects of probiotics in environmental toxicants-induced hepatotoxicity and current findings on this therapeutic approach's experimental and clinical trials.

Efficacy and safety of mesenchymal stem cell therapies in retinitis pigmentosa: a systematic review and meta-analysis

BACKGROUND

Retinitis pigmentosa (RP) is a retinal dystrophy and genetically heterogeneous group that causes vision loss and necessitates innovative therapeutic strategies, and mesenchymal stem cell (MSC) therapy has shown potential due to its regenerative and immunomodulatory properties. This meta-analysis aims to evaluate the efficacy and safety of MSC therapies in improving visual outcomes, focusing on the impact of various MSC types, administration methods, and duration of benefits.

METHODS

A systematic search of peer-reviewed studies was conducted to identify clinical trials and observational studies investigating MSC therapies for retinal conditions. Outcomes of interest included best-corrected visual acuity (BCVA), central macular thickness, retinal sensitivity, quality of life, and safety profiles. Data were synthesized and analyzed using random-effects meta-analysis to calculate pooled effect sizes and heterogeneity.

PROSPERO

CRD42024618158.

RESULTS

Eleven studies involving 355 RP patients were included. Umbilical cord-derived MSCs and bone marrow-derived MSCs demonstrated significant short-term improvements in BCVA and retinal function. Subretinal and suprachoroidal delivery methods were associated with better outcomes compared to systemic infusion. Adverse effects were minimal, with transient inflammation being the most reported. The duration of benefits varied, with most studies reporting sustained improvements up to 12 months, while long-term efficacy beyond this period was less conclusive.

CONCLUSIONS

MSC therapies show promise in improving visual function and retinal health, with safety profiles supporting their clinical feasibility. However, differences in administration methods and MSC types influence outcomes. Further large-scale, long-term randomized controlled trials are needed to optimize treatment protocols and validate sustained benefits.

Mediator kinase inhibition drives myometrial stem cell differentiation and the uterine fibroid phenotype through super-enhancer reprogramming

Uterine fibroids (UFs) are the most common non-cutaneous tumors in women worldwide. UFs arise from genetic alterations in myometrial stem cells (MM SCs) that trigger their transformation into tumor-initiating cells (UF SCs). Mutations in the RNA polymerase II Mediator subunit MED12 are dominant drivers of UFs, accounting for 70% of these clinically significant lesions. Biochemically, UF driver mutations in MED12 disrupt CDK8/19 kinase activity in Mediator, but how Mediator kinase disruption triggers MM SC transformation remains unknown. Here, we show that pharmacologic inhibition of CDK8/19 in MM SCs removes a barrier to myogenic differentiation down an altered pathway characterized by molecular phenotypes characteristic of UFs, including oncogenic growth and extracellular matrix (ECM) production. These perturbations appear to be induced by transcriptomic changes, arising in part through epigenomic alteration and super-enhancer reprogramming, that broadly recapitulate those found in MED12-mutant UFs. Altogether, these findings provide new insights concerning the biological role of CDK8/19 in MM SC biology and UF formation. KEY MESSAGES: Mediator kinase inhibition in myometrial stem cells (MM SCs) induces spontaneous differentiation. Transcriptional changes upon Mediator kinase inhibition recapitulate those of MED12 mutant uterine fibroids (UFs). Such transcriptional changes are partially mediated by super-enhancer reprogramming. Mediator kinase functions to enforce cell states and its loss induces cellular plasticity.

Effects of stem cell therapy on preclinical stroke

Stroke, particularly ischemic stroke, is a leading cause of global mortality and disability. It is caused by blood flow obstruction and reduced oxygen delivery to brain tissue. Conventional treatments, such as tissue plasminogen activator (tPA) and mechanical thrombectomy (MT), have limited efficacy in repairing neural damage and carry risks of adverse effects. As a result, stem cell therapies, including mesenchymal stem cells (MSCs), have emerged as promising approaches for enhancing neural recovery and offering neuroprotection in ischemic stroke management. MSCs offer multifaceted benefits, such as reducing inflammation, protecting neurons, and promoting angiogenesis and neurogenesis. Recent evidence highlights the importance of MSC secretomes-extracellular vesicles (EVs) and exosomes rich in neuroprotective factors, such as microRNAs, proteins, and cytokines. These bioactive molecules demonstrated considerable efficacy in preclinical models by reducing neuroinflammation, preserving neurovascular integrity, and promoting cellular repair in ischemic environments. Preclinical in vitro and in vivo studies demonstrate the potential of the MSC secretomes to restore brain function after ischemic stroke. This is achieved by enhancing neuronal survival through mechanisms such as angiogenesis or vascular recovery, neuroprotection including modulation of immune or inflammatory responses, apoptosis, and autophagy, and promoting post-stroke neurogenesis. This review explores the translational challenges and future potential of integrating conventional ischemic stroke therapies with stem cell-based or cell-free approaches. The present study synthesizes current insights into the role of MSC-derived secretomes from both in vitro and in vivo studies.

Cyclin-dependent protein kinases and cell cycle regulation in biology and disease

Cyclin Dependent Kinases (CDKs) are closely connected to the regulation of cell cycle progression, having been first identified as the kinases able to drive cell division. In reality, the human genome contains 20 different CDKs, which can be divided in at least three different sub-family with different functions, mechanisms of regulation, expression patterns and subcellular localization. Most of these kinases play fundamental roles the normal physiology of eucaryotic cells; therefore, their deregulation is associated with the onset and/or progression of multiple human disease including but not limited to neoplastic and neurodegenerative conditions. Here, we describe the functions of CDKs, categorized into the three main functional groups in which they are classified, highlighting the most relevant pathways that drive their expression and functions. We then discuss the potential roles and deregulation of CDKs in human pathologies, with a particular focus on cancer, the human disease in which CDKs have been most extensively studied and explored as therapeutic targets. Finally, we discuss how CDKs inhibitors have become standard therapies in selected human cancers and propose novel ways of investigation to export their targeting from cancer to other relevant chronic diseases. We hope that the effort we made in collecting all available information on both the prominent and lesser-known CDK family members will help in identify and develop novel areas of research to improve the lives of patients affected by debilitating chronic diseases.

Mediator kinase inhibition drives myometrial stem cell differentiation and the uterine fibroid phenotype through super-enhancer reprogramming

Uterine fibroids (UFs) are the most common non-cutaneous tumors in women worldwide. UFs arise from genetic alterations in myometrial stem cells (MM SCs) that trigger their transformation into tumor initiating cells (UF SCs). Mutations in the RNA polymerase II Mediator subunit MED12 are dominant drivers of UFs, accounting for 70% of these clinically significant lesions. Biochemically, UF driver mutations in MED12 disrupt CDK8/19 kinase activity in Mediator, but how Mediator kinase disruption triggers MM SC transformation remains unknown. Here, we show that pharmacologic inhibition of CDK8/19 in MM SCs removes a barrier to myogenic differentiation down an altered pathway characterized by molecular phenotypes characteristic of UFs, including oncogenic growth and extracellular matrix (ECM) production. These perturbations appear to be induced by transcriptomic changes, arising in part through epigenomic alteration and super-enhancer reprogramming, that broadly recapitulate those found in MED12-mutant UFs. Altogether these findings provide new insights concerning the biological role of CDK8/19 in MM SC biology and UF formation.

Mesenchymal Stem Extracellular Vesicles in Various Respiratory Diseases: A New Opportunity

Lung diseases are associated with high morbidity and mortality rates, thereby jeopardizing human health and imposing a great burden on society. Currently, lung diseases are mainly treated with medications, oxygen therapy and mechanical ventilation, but these approaches are unable to effectively reduce the mortality rate. Therefore, lung transplantation remains the ultimate treatment for various chronic lung diseases, but this treatment is also hindered by the limited availability of lung sources, immature technology and a low survival rate after transplantation. With constant changes in the environment, pathogens, type and amount of harmful substances and the prevalence of respiratory diseases, there is an urgent need to identify alternative treatment methods. Research on stem cell therapy has been very successful in recent years, and mesenchymal stem cells (MSCs), together with their secretory bodies, play a significant therapeutic role. Extracellular vesicles of MSCs (MSC-EVs) are also major components of the paracrine secretion of MSCs, including exosomes, microvesicles, and apoptotic bodies, among which exosomes are the most typical. MSC-EVs are believed to be present in various tissues of the human body where they can carry proteins, DNA, RNA and biologically active factors, just to name a few. They can also transmit various biological signals to participate in different biological activities, including the maintenance of homeostasis within the tissue. Several studies have further demonstrated that MSCs and their generated extracellular vesicles play an important role in the treatment of diseases. In this paper, the origin, properties and roles of MSCs and MSC-EVs are reviewed, the mechanisms of different lung diseases, the limitations of current therapeutic options and the roles of MSC-EVs in Chronic Obstructive Pulmonary Disease, asthma, infectious lung disease, lung cancer, pulmonary fibrosis, pulmonary arterial hypertension, and acute lung injury/ acute respiratory distress syndrome are also discussed (Figure 1). In addition, the current limitations and possible future research directions are also discussed in view of providing new ideas for the role of MSC-EVs in the treatment of lung diseases.

Regulating the proinflammatory response to composite biomaterials by targeting immunometabolism

Composite biomaterials comprising polylactide (PLA) and hydroxyapatite (HA) are applied in bone, cartilage and dental regenerative medicine, where HA confers osteoconductive properties. However, after surgical implantation, adverse immune responses to these composites can occur, which have been attributed to size and morphology of HA particles. Approaches to effectively modulate these adverse immune responses have not been described. PLA degradation products have been shown to alter immune cell metabolism (immunometabolism), which drives the inflammatory response. Accordingly, to modulate the inflammatory response to composite biomaterials, inhibitors were incorporated into composites comprised of amorphous PLA (aPLA) and HA (aPLA + HA) to regulate glycolytic flux. Inhibition at specific steps in glycolysis reduced proinflammatory (CD86+CD206-) and increased pro-regenerative (CD206+) immune cell populations around implanted aPLA + HA. Notably, neutrophil and dendritic cell (DC) numbers along with proinflammatory monocyte and macrophage populations were decreased, and Arginase 1 expression among DCs was increased. Targeting immunometabolism to control the proinflammatory response to biomaterial composites, thereby creating a pro-regenerative microenvironment, is a significant advance in tissue engineering where immunomodulation enhances osseointegration and angiogenesis, which could lead to improved bone regeneration.

Engineering extracellular vesicles for ROS scavenging and tissue regeneration

Stem cell therapy holds promise for tissue regeneration, yet significant challenges persist. Emerging as a safer and potentially more effective alternative, extracellular vesicles (EVs) derived from stem cells exhibit remarkable abilities to activate critical signaling cascades, thereby facilitating tissue repair. EVs, nano-scale membrane vesicles, mediate intercellular communication by encapsulating a diverse cargo of proteins, lipids, and nucleic acids. Their therapeutic potential lies in delivering cargos, activating signaling pathways, and efficiently mitigating oxidative stress-an essential aspect of overcoming limitations in stem cell-based tissue repair. This review focuses on engineering and applying EVs in tissue regeneration, emphasizing their role in regulating reactive oxygen species (ROS) pathways. Additionally, we explore strategies to enhance EV therapeutic activity, including functionalization and incorporation of antioxidant defense proteins. Understanding these molecular mechanisms is crucial for optimizing EV-based regenerative therapies. Insights into EV and ROS signaling modulation pave the way for targeted and efficient regenerative therapies harnessing the potential of EVs.

Extracellular vesicles in nanomedicine and regenerative medicine: A review over the last decade

Small extracellular vesicles (sEVs) are known to be secreted by a vast majority of cells. These sEVs, specifically exosomes, induce specific cell-to-cell interactions and can activate signaling pathways in recipient cells through fusion or interaction. These nanovesicles possess several desirable properties, making them ideal for regenerative medicine and nanomedicine applications. These properties include exceptional stability, biocompatibility, wide biodistribution, and minimal immunogenicity. However, the practical utilization of sEVs, particularly in clinical settings and at a large scale, is hindered by the expensive procedures required for their isolation, limited circulation lifetime, and suboptimal targeting capacity. Despite these challenges, sEVs have demonstrated a remarkable ability to accommodate various cargoes and have found extensive applications in the biomedical sciences. To overcome the limitations of sEVs and broaden their potential applications, researchers should strive to deepen their understanding of current isolation, loading, and characterization techniques. Additionally, acquiring fundamental knowledge about sEVs origins and employing state-of-the-art methodologies in nanomedicine and regenerative medicine can expand the sEVs research scope. This review provides a comprehensive overview of state-of-the-art exosome-based strategies in diverse nanomedicine domains, encompassing cancer therapy, immunotherapy, and biomarker applications. Furthermore, we emphasize the immense potential of exosomes in regenerative medicine.

Pretreated MSCs with IronQ Transplantation Attenuate Microglia Neuroinflammation via the cGAS-STING Signaling Pathway

BACKGROUND

Intracerebral hemorrhage (ICH), a devastating form of stroke, is characterized by elevated morbidity and mortality rates. Neuroinflammation is a common occurrence following ICH. Mesenchymal stem cells (MSCs) have exhibited potential in treating brain diseases due to their anti-inflammatory properties. However, the therapeutic efficacy of MSCs is limited by the intense inflammatory response at the transplantation site in ICH. Hence, enhancing the function of transplanted MSCs holds considerable promise as a therapeutic strategy for ICH. Notably, the iron-quercetin complex (IronQ), a metal-quercetin complex synthesized through coordination chemistry, has garnered significant attention for its biomedical applications. In our previous studies, we have observed that IronQ exerts stimulatory effects on cell growth, notably enhancing the survival and viability of peripheral blood mononuclear cells (PBMCs) and MSCs. This study aimed to evaluate the effects of pretreated MSCs with IronQ on neuroinflammation and elucidate its underlying mechanisms.

METHODS

The ICH mice were induced by injecting the collagenase I solution into the right brain caudate nucleus. After 24 hours, the ICH mice were randomly divided into four subgroups, the model group (Model), quercetin group (Quercetin), MSCs group (MSCs), and pretreated MSCs with IronQ group (MSCs+IronQ). Neurological deficits were re-evaluated on day 3, and brain samples were collected for further analysis. TUNEL staining was performed to assess cell DNA damage, and the protein expression levels of inflammatory factors and the cGAS-STING signaling pathway were investigated and analyzed.

RESULTS

Pretreated MSCs with IronQ effectively mitigate neurological deficits and reduce neuronal inflammation by modulating the microglial polarization. Moreover, the pretreated MSCs with IronQ suppress the protein expression levels of the cGAS-STING signaling pathway.

CONCLUSION

These findings suggest that pretreated MSCs with IronQ demonstrate a synergistic effect in alleviating neuroinflammation, thereby improving neurological function, which is achieved through the inhibition of the cGAS-STING signaling pathway.

Potential applications of mesenchymal stem cells and their derived exosomes in regenerative medicine

INTRODUCTION

Regenerative medicine involves the replacement of damaged cells, tissues, or organs to restore normal function. Mesenchymal stem cells (MSCs) and exosomes secreted by MSCs have unique advantages that make them a suitable candidate in the field of regenerative medicine.

AREAS COVERED

This article provides a comprehensive overview of regenerative medicine, focusing on the use of MSCs and their exosomes as potential therapies for replacing damaged cells, tissues, or organs. This article discusses the distinct advantages of both MSCs and their secreted exosomes, including their immunomodulatory effects, lack of immunogenicity, and recruitment to damaged areas. While both MSCs and exosomes have these advantages, MSCs also have the unique ability to self-renew and differentiate. This article also assesses the current challenges associated with the application of MSCs and their secreted exosomes in therapy. We have reviewed proposed solutions for improving MSC or exosome therapy, including ex-vivo preconditioning strategies, genetic modification, and encapsulation. Literature search was conducted using Google Scholar and PubMed databases.

EXPERT OPINION

Providing insight into the future development of MSC and exosome-based therapies and to encourage the scientific community to focus on the identified gaps, develop appropriate guidelines, and enhance the clinical application of these therapies.