Intravital imaging and single cell transcriptomic analysis for engraftment of mesenchymal stem cells in an animal model of interstitial cystitis/bladder pain syndrome

Single-cell technology for cell-based drug delivery and pharmaceutical research

Leveraging the capacity to precisely manipulate and analyze individual cells, single-cell technology has rapidly become an indispensable tool in the advancement of cell-based drug delivery systems and innovative cell therapies. This technology offers powerful means to address cellular heterogeneity and significantly enhance therapeutic efficacy. Recent breakthroughs in techniques such as single-cell electroporation, mechanical perforation, and encapsulation, particularly when integrated with microfluidics and bioelectronics, have led to remarkable improvements in drug delivery efficiency, reductions in cytotoxicity, and more precise targeting of therapeutic effects. Moreover, single-cell analyses, including advanced sequencing and high-resolution sensing, offer profound insights into complex disease mechanisms, the development of drug resistance, and the intricate processes of stem cell differentiation. This review summarizes the most significant applications of these single-cell technologies, highlighting their impact on the landscape of modern biomedicine. Furthermore, it provides a forward-looking perspective on future research directions aimed at further optimizing drug delivery strategies and enhancing therapeutic outcomes in the treatment of various diseases.

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.

Deciphering cellular complexity: advances and future directions in single-cell protein analysis

Single-cell protein analysis has emerged as a powerful tool for understanding cellular heterogeneity and deciphering the complex mechanisms governing cellular function and fate. This review provides a comprehensive examination of the latest methodologies, including sophisticated cell isolation techniques (Fluorescence-Activated Cell Sorting (FACS), Magnetic-Activated Cell Sorting (MACS), Laser Capture Microdissection (LCM), manual cell picking, and microfluidics) and advanced approaches for protein profiling and protein-protein interaction analysis. The unique strengths, limitations, and opportunities of each method are discussed, along with their contributions to unraveling gene regulatory networks, cellular states, and disease mechanisms. The importance of data analysis and computational methods in extracting meaningful biological insights from the complex data generated by these technologies is also highlighted. By discussing recent progress, technological innovations, and potential future directions, this review emphasizes the critical role of single-cell protein analysis in advancing life science research and its promising applications in precision medicine, biomarker discovery, and targeted therapeutics. Deciphering cellular complexity at the single-cell level holds immense potential for transforming our understanding of biological processes and ultimately improving human health.

Pharmacokinetic characteristics of mesenchymal stem cells in translational challenges

Over the past two decades, mesenchymal stem/stromal cell (MSC) therapy has made substantial strides, transitioning from experimental clinical applications to commercial products. MSC therapies hold considerable promise for treating refractory and critical conditions such as acute graft-versus-host disease, amyotrophic lateral sclerosis, and acute respiratory distress syndrome. Despite recent successes in clinical and commercial applications, MSC therapy still faces challenges when used as a commercial product. Current detection methods have limitations, leaving the dynamic biodistribution, persistence in injured tissues, and ultimate fate of MSCs in patients unclear. Clarifying the relationship between the pharmacokinetic characteristics of MSCs and their therapeutic effects is crucial for patient stratification and the formulation of precise therapeutic regimens. Moreover, the development of advanced imaging and tracking technologies is essential to address these clinical challenges. This review provides a comprehensive analysis of the kinetic properties, key regulatory molecules, different fates, and detection methods relevant to MSCs and discusses concerns in evaluating MSC druggability from the perspective of integrating pharmacokinetics and efficacy. A better understanding of these challenges could improve MSC clinical efficacy and speed up the introduction of MSC therapy products to the market.

Promising Experimental Treatment in Animal Models and Human Studies of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain Syndrome (IC/BPS) remains a mysterious and intricate urological disorder, presenting significant challenges to healthcare providers. Traditional guidelines for IC/BPS follow a hierarchical model based on symptom severity, advocating for conservative interventions as the initial step, followed by oral pharmacotherapy, intravesical treatments, and, in refractory cases, invasive surgical procedures. This approach embraces a multi-tiered strategy. However, the evolving understanding that IC/BPS represents a paroxysmal chronic pain syndrome, often involving extravesical manifestations and different subtypes, calls for a departure from this uniform approach. This review provides insights into recent advancements in experimental strategies in animal models and human studies. The identified therapeutic approaches fall into four categories: (i) anti-inflammation and anti-angiogenesis using monoclonal antibodies or immune modulation, (ii) regenerative medicine, including stem cell therapy, platelet-rich plasma, and low-intensity extracorporeal shock wave therapy, (iii) drug delivery systems leveraging nanotechnology, and (iv) drug delivery systems assisted by energy devices. Future investigations will require a broader range of animal models, studies on human bladder tissues, and well-designed clinical trials to establish the efficacy and safety of these therapeutic interventions.

Stem cell therapy for interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic disease with limited treatment options. Current multidisciplinary approach targeting bladder inflammation and urothelial dysfunction has limited durable effect that major surgery is ultimately required for both Hunner and non-Hunner type IC. Various investigational attempts are underway to avoid such operations and preserve the urinary bladder. Stem cell therapy is a fascinating option for treating chronic illnesses. Stem cells can self-renew, restore damaged tissue, and have paracrine effects. The therapeutic efficacy and safety of stem cell therapy have been demonstrated in numerous preclinical models, primarily chemically induced cystitis rat models. Only one clinical trial (phase 1 study) has investigated the safety of human embryonic stem cell-derived mesenchymal stem cells in three Hunner-type IC patients. Under general anesthesia, participants underwent cystoscopic submucosal stem cell injection (2.0 × 107 stem cells/5 mL). No safety issues were reported up to 12 months of follow-up and long-term follow-up (up to 3 years). Although there were variations in therapeutic response, all patients reported significant improvement in pain at 1 month postoperatively. One patient underwent fulguration of the Hunner lesion after the trial, but others reported an overall improvement in pain. The analysis on phase 1/2a trial which had several modifications in protocol is currently ongoing. Despite several limitations that need to be overcome, stem cell therapy could be a potential therapeutic option for treating IC/BPS. Clinical outcome on phase 1/2a trial is important and might provide more insight into the clinical application of stem cell therapy for IC/BPS.

Superoxide dismutase 2 scavenges ROS to promote osteogenic differentiation of human periodontal ligament stem cells by regulating Smad3 in alveolar bone-defective rats

BACKGROUND

Osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) is an essential event in alveolar bone regeneration. Oxidative stress may be the main inhibiting factor of hPDLSC osteogenesis. Superoxide dismutase 2 (SOD2) is a key antioxidant enzyme, but its effect on hPDLSC osteogenic differentiation is unclear.

METHODS

Several surface markers were detected by flow cytometry, and the differentiation potential of hPDLSCs was validated by alkaline phosphatase (ALP), Alizarin Red S, and Oil Red O staining. Osteogenic indicators of hPDLSCs were detected by real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and ALP staining. Furthermore, alveolar bone defect rat models were analyzed through micro-CT, hematoxylin and eosin, and Masson staining. The intracellular reactive oxygen species (ROS) level was evaluated by a ROS assay kit. Finally, the expression of SOD2, Smad3, and p-Smad3 in hPDLSCs was detected by RT-qPCR and Western blotting (WB).

RESULTS

SOD2 positively regulated the gene and protein expressions of ALP, BMP6, and RUNX2 in hPDLSCs (p < 0.05). Ideal bone formation and continuous cortical bone were obtained by transplanting LV-SOD2 hPDLSCs (lentivirus vector for overexpressing SOD2 in hPDLSCs) in vivo. Exogenous H2O2 downregulated osteogenic indicators (ALP, BMP6, RUNX2) in hPDLSCs (p < 0.05); this was reversed by overexpression of SOD2. WB results showed that the Smad3 and p-Smad3 signaling pathways participated in the osteogenic process of SOD2 in hPDLSCs.

CONCLUSION

SOD2 positively regulated hPDLSC osteogenic differentiation in vitro and in vivo. Mechanistically, SOD2 promotes hPDLSC osteogenic differentiation by regulating the phosphorylation of Smad3 to scavenge ROS. This work provides a theoretical basis for the treatment of alveolar bone regeneration.

Stem cells and pain

Pain can be defined as an unpleasant sensory and emotional experience caused by either actual or potential tissue damage or even resemble that unpleasant experience. For years, science has sought to find treatment alternatives, with minimal side effects, to relieve pain. However, the currently available pharmacological options on the market show significant adverse events. Therefore, the search for a safer and highly efficient analgesic treatment has become a priority. Stem cells (SCs) are non-specialized cells with a high capacity for replication, self-renewal, and a wide range of differentiation possibilities. In this review, we provide evidence that the immune and neuromodulatory properties of SCs can be a valuable tool in the search for ideal treatment strategies for different types of pain. With the advantage of multiple administration routes and dosages, therapies based on SCs for pain relief have demonstrated meaningful results with few downsides. Nonetheless, there are still more questions than answers when it comes to the mechanisms and pathways of pain targeted by SCs. Thus, this is an evolving field that merits further investigation towards the development of SC-based analgesic therapies, and this review will approach all of these aspects.

Embryonic-stem-cell-derived mesenchymal stem cells relieve experimental contact urticaria by regulating the functions of mast cells and T cells

Contact urticaria (CU) is an inflammatory skin disorder triggered by specific substances upon skin contact, leading to immediate acute or chronic manifestations characterized by swelling and redness. While mesenchymal stem cells (MSCs) are increasingly recognized for their therapeutic potential in immune diseases, research on the efficacy and mechanisms of stem cell therapy for urticaria remains scarce. This study investigates the regulatory role of embryonic-stem-cell-derived multipotent MSCs (M-MSCs) administered in a CU mouse model. Therapeutic effects of M-MSC administration were assessed in a Trimellitic anhydride-induced contact urticaria model, revealing significant inhibition of urticarial reactions, including ear swelling, itchiness, and skin lesion. Moreover, M-MSC administration exerted control over effector T cell activities in major lymphoid and peripheral tissues, while also suppressing mast cell degranulation in peripheral tissues. Notably, the inhibitory effects mediated by M-MSCs were found to be TGF-β-dependent. Our study demonstrates the capacity of M-MSCs to regulate contact urticaria in a murine model, harmonizing the activation of inflammatory T cells and mast cells. Additionally, we suggest that TGF-β derived from M-MSCs could play a pivotal role as an inhibitory mechanism in contact urticaria.

Glutathione dynamics is a potential predictive and therapeutic trait for neoadjuvant chemotherapy response in bladder cancer

Radical cystectomy with preoperative cisplatin-based neoadjuvant chemotherapy (NAC) is the standard care for muscle-invasive bladder cancers (MIBCs). However, the complete response rate to this modality remains relatively low, and current clinicopathologic and molecular classifications are inadequate to predict NAC response in patients with MIBC. Here, we demonstrate that dysregulation of the glutathione (GSH) pathway is fundamental for MIBC NAC resistance. Comprehensive analysis of the multicohort transcriptomes reveals that GSH metabolism and immune-response genes are enriched in NAC-resistant and NAC-sensitive MIBCs, respectively. A machine-learning-based tumor/stroma classifier is applied for high-throughput digitalized immunohistochemistry analysis, finding that GSH dynamics proteins, including glutaminase-1, are associated with NAC resistance. GSH dynamics is activated in cisplatin-resistant MIBC cells, and combination treatment with a GSH dynamics modulator and cisplatin significantly suppresses tumor growth in an orthotopic xenograft animal model. Collectively, these findings demonstrate the predictive and therapeutic values of GSH dynamics in determining the NAC response in MIBCs.

Dissecting the Interrelationship between COVID-19 and Diabetes Mellitus

COVID-19 disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to enormous morbidity and mortality worldwide. After gaining entry into the human host, the virus initially infects the upper and lower respiratory tract, subsequently invading multiple organs, including the pancreas. While on one hand, diabetes mellitus (DM) is a significant risk factor for severe COVID-19 infection and associated death, recent reports have shown the onset of DM in COVID-19-recovered patients. SARS-CoV-2 infiltrates the pancreatic islets and activates stress response and inflammatory signaling pathways, impairs glucose metabolism, and consequently leads to their death. Indeed, the pancreatic autopsy samples of COVID-19 patients reveal the presence of SARS-CoV-2 particles in β-cells. The current review describes how the virus enters the host cells and activates an immunological response. Further, it takes a closer look into the interrelationship between COVID-19 and DM with the aim to provide mechanistic insights into the process by which SARS-CoV-2 infects the pancreas and mediates dysfunction and death of endocrine islets. The effects of known anti-diabetic interventions for COVID-19 management are also discussed. The application of mesenchymal stem cells (MSCs) as a future therapy for pancreatic β-cells damage to reverse COVID-19-induced DM is also emphasized.

Fabrication of high-performance cell-imprinted polymers based on AuNPs/MXene composites via metal-free visible light-induced ATRP

Cell-imprinted polymers (CIPs) for yeasts were fabricated via metal-free visible-light-induced atom transfer radical polymerization (MVL ATRP) on the surface of a glassy carbon electrode (GCE) which had been modified with gold nanoparticles (AuNPs)/MXene (Ti₃C₂T_x) composites. Here, the AuNPs/Ti₃C₂T_x composites form a macroporous structure, which could improve the electron transfer rate of the materials and facilitate the leaving or rebinding of cells. Methacrylic acid (MAA) and N,N'-methylene bis-acrylamide (MBA) were selected as the functional monomer and cross-linker of CIPs, because they could form efficient hydrogen bonding with mannan from yeast cell walls. The obtained electrode (CIPs/AuNPs/Ti₃C₂T_x/GCE) was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Further experiments indicated that the CIPs/AuNPs/Ti₃C₂T_x/GCE electrode could be utilized as an electrochemical biosensor to determine yeast cells by differential pulse voltammetry (DPV). The linear response range was 1.0 × 10² to 1.0 × 10⁹ cells per mL and the detection limit was 20 cells per mL (S/N = 3). The CIPs/AuNPs/Ti₃C₂T_x/GCE electrode also showed good selectivity, repeatability, reproducibility, and regeneration. Finally, the proposed sensor was used to detect yeast cells in commercial samples of Saccharomyces boulardii sachets by a standard addition method. The obtained recovery was from 96.9 to 104.8% showing its potential applications in clinical and diagnostic research.

Safety of Human Embryonic Stem Cell-derived Mesenchymal Stem Cells for Treating Interstitial Cystitis: A Phase I Study

There are still no definite treatment modalities for interstitial cystitis (IC). Meanwhile, stem cell therapy is rising as potential alternative for various chronic diseases. This study aimed to investigate the safety of the clinical-grade mesenchymal stem cells (MSCs) derived from human embryonic stem cells (hESCs), code name MR-MC-01 (SNU42-MMSCs), in IC patients. Three female IC patients with (1) symptom duration >6 months, (2) visual pain analog scale (VAS) ≥4, and (3) one or two Hunner lesions <2 cm in-office cystoscopy within 1 month were included. Under general anesthesia, participants received cystoscopic submucosal injection of SNU42-MMSCs (2.0 × 107/5 mL) at the center or margin of Hunner lesions and other parts of the bladder wall except trigone with each injection volume of 1 mL. Follow-up was 1, 3, 6, 9, and 12 months postoperatively. Patients underwent scheduled follow-ups, and symptoms were evaluated with validated questionnaires at each visit. No SNU42-MMSCs-related adverse events including immune reaction and abnormalities on laboratory tests and image examinations were reported up to 12-month follow-up. VAS pain was temporarily improved in all subjects. No de novo Hunner lesions were observed and one lesion of the first subject was not identifiable on 12-month cystoscopy. This study reports the first clinical application of transurethral hESC-derived MSC injection in three patients with IC. hESC-based therapeutics was safe and proved to have potential therapeutic efficacy in IC patients. Stem cell therapy could be a potential therapeutic option for treating IC.

Immunomodulation of Pluripotent Stem Cell-Derived Mesenchymal Stem Cells in Rotator Cuff Tears Model

Background: Rotator cuff tears (RCTs) induce chronic muscle weakness and shoulder pain. Treatment of RCT using surgery or drugs causes lipid infiltration and fibrosis, which hampers tissue regeneration and complete recovery. The pluripotent stem cell-derived multipotent mesenchymal stem cells (M-MSCs) represent potential candidate next-generation therapies for RCT. Methods: The difference between M-MSCs and adult-MSCs was compared and analyzed using next-generation sequencing (NGS). In addition, using a rat model of RCT, the muscle recovery ability of M-MSCs and adult-MSCs was evaluated by conducting a histological analysis and monitoring the cytokine expression level. Results: Using NGS, it was confirmed that M-MSC was suitable for transplantation because of its excellent ability to regulate inflammation that promotes tissue repair and reduced apoptosis and rejection during transplantation. In addition, while M-MSCs persisted for up to 8 weeks in vivo, they significantly reduced inflammation and adipogenesis-related cytokine levels in rat muscle. Significant differences were also confirmed in histopathological remission. Conclusions: M-MSCs remain in the body longer to modulate immune responses in RCTs and have a greater potential to improve muscle recovery by alleviating acute inflammatory responses. This indicates that M-MSCs could be used in potential next-generation RCT therapies.