Dosing Limitation for Intra-Renal Arterial Infusion of Mesenchymal Stromal Cells

Dynamic conditioning of porcine kidney grafts with extracellular vesicles derived from urine progenitor cells: A proof-of-concept study

 : Among strategies to limit ischemia/reperfusion (IR) injuries in transplantation, cell therapy using stem cells to condition/repair transplanted organs appears promising. We hypothesized that using a cell therapy based on extracellular vesicles (EVs) derived from urine progenitor cells (UPCs) during hypothermic and normothermic machine perfusion can prevent IR-related kidney damage. We isolated and characterized porcine UPCs and their extracellular vesicles (EVs). Then these were used in an ex vivo porcine kidney preservation model. Kidneys were subjected to warm ischemia (32 min) and then preserved by hypothermic machine perfusion (HMP) for 24 h before 5 h of normothermic machine perfusion (NMP). Three groups were performed (n = 5-6): Group 1 (G1): HMP/vehicle + NMP/vehicle, Group 2 (G2): HMP/EVs + NMP/vehicle, Group 3 (G3): HMP/EVs + NMP/EVs. Porcine UPCs were successfully isolated from urine and fully characterized as well as their EVs which were found of expected size/phenotype. EVs injection during HMP alone, NMP alone, or both was feasible and safe and did not impact perfusion parameters. However, cell damage markers (LDH, ASAT) were decreased in G3 compared with G1, and G3 kidneys displayed a preserved tissue integrity with reduced tubular dilatation and inflammation notably. However, renal function indicators such as creatinine clearance measured for 5 h of normothermic perfusion or NGAL perfusate's level were not modified by EVs injection. Regarding perfusate analysis, metabolomic analyses and cytokine quantification showed an immunomodulation signature in G3 compared with G1 and highlighted potential metabolic targets. In vitro, EVs as well as perfusates from G3 partially recovered endothelial cell metabolic activity after hypoxia. Finally, RNA-seq performed on kidney biopsies showed different profiles between G1 and G3 with regulation of potential IR targets of EVs therapy. We showed the feasibility/efficacy of UPC-EVs for hypothermic/normothermic kidney conditioning before transplantation, paving the way for combining machine perfusion with EVs-based cell therapy for organ conditioning. HIGHLIGHTS: ·UPCs from porcine urine can be used to generate a cell therapy product based on extracellular vesicles (pUPC-EVs). ·pUPC-EVs injection during HMP and NMP decreases cell damage markers and has an immunomodulatory effect. ·pUPC-EVs-treated kidneys have distinct biochemical, metabolic, and transcriptomic profiles highlighting targets of interest. ·Our results pave the way for combining machine perfusion with EV-based cell therapy for kidney conditioning.

Targeted therapeutic strategies for the kidney

INTRODUCTION

Kidney diseases impose a significant burden with high incidence and mortality rates. Current treatment options for kidney diseases are limited, necessitating urgent development of novel and effective therapeutic strategies to delay or reverse disease progression. Targeted therapies for the kidney hold promise in significantly enhancing treatment outcomes, offering hope to patients afflicted with renal disorders.

AREAS COVERED

This review summarized advances in kidney-targeted therapies including genes, peptides and proteins, cell-based, nanoparticles, and localized delivery routes. We also explored the potential clinical applications, prospects, and challenges of targeted therapies for renal disorders.

EXPERT OPINION

Advances in targeted therapies for renal conditions have enhanced therapeutic outcomes. Clinical application of kidney-targeted therapies is currently limited by renal structure and the scarcity of robust biomarkers. Bridging the gap from basic and pre-clinical research targeting the kidney to achieving clinical translation remains a formidable challenge.

Machine Perfusion and Bioengineering Strategies in Transplantation-Beyond the Emerging Concepts

Solid organ transplantation has progressed rapidly over the decades from the first experimental procedures to its role in the modern era as an established treatment for end-stage organ disease. Solid organ transplantation including liver, kidney, pancreas, heart, and lung transplantation, is the definitive option for many patients, but despite the advances that have been made, there are still significant challenges in meeting the demand for viable donor grafts. Furthermore, post-operatively, the recipient faces several hurdles, including poor early outcomes like primary graft dysfunction and acute and chronic forms of graft rejection. In an effort to address these issues, innovations in organ engineering and treatment have been developed. This review covers efforts made to expand the donor pool including bioengineering techniques and the use of ex vivo graft perfusion. It also covers modifications and treatments that have been trialed, in addition to research efforts in both abdominal organs and thoracic organs. Overall, this article discusses recent innovations in machine perfusion and organ bioengineering with the aim of improving and increasing the quality of donor organs.

Neuroinflammation mechanism underlying neuropathic pain: the role of mesenchymal stem cell in neuroglia

Pain is an essential aspect of the body's physiological response to unpleasant noxious stimuli from either external sustained injuries or an internal disease condition that occurs within the body. Generally, pain is temporary. However, in patients with neuropathic pain, the experienced pain is persistent and uncontrollable, with an unsatisfactory treatment effectiveness. The activation of the immune system is a crucial factor in both central and peripheral neuropathic pain. The immune response plays an important role in the progression of the stages of neuropathic pain, and acts not only as pain mediators, but also produce analgesic molecules. Neuropathic pain has long been described as a result of dysfunctional nerve activities. However, there is substantial evidence indicating that the regulation of hyperalgesia is mediated by astrocytes and microglia activation. Mesenchymal stem cells currently hold an optimal potential in managing pain, as they can migrate to damaged tissues and have a robust immunosuppressive role for autologous or heterologous transplantation. Moreover, mesenchymal stem cells revealed their immunomodulatory capabilities by secreting growth factors and cytokines through direct cell interactions. The main idea underlying the use of mesenchymal stem cells in pain management is that these cells can replace damaged nerve cells by releasing neurotrophic factors. This property makes them the perfect option to modulate and treat neuropathic pain, which is notoriously difficult to treat.

Mesenchymal stem cells and their derived exosomes for the treatment of COVID-19

Coronavirus disease 2019 (COVID-19) is an acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 infection typically presents with fever and respiratory symptoms, which can progress to severe respiratory distress syndrome and multiple organ failure. In severe cases, these complications may even lead to death. One of the causes of COVID-19 deaths is the cytokine storm caused by an overactive immune response. Therefore, suppressing the overactive immune response may be an effective strategy for treating COVID-19. Mesenchymal stem cells (MSCs) and their derived exosomes (MSCs-Exo) have potent homing abilities, immunomodulatory functions, regenerative repair, and antifibrotic effects, promising an effective tool in treating COVID-19. In this paper, we review the main mechanisms and potential roles of MSCs and MSCs-Exo in treating COVID-19. We also summarize relevant recent clinical trials, including the source of cells, the dosage and the efficacy, and the clinical value and problems in this field, providing more theoretical references for the clinical use of MSCs and MSCs-Exo in the treatment of COVID-19.

Mesenchymal stem cell therapy in diabetic foot ulcer: An updated comprehensive review

Background

Diabetes has evolved into a worldwide public health issue. One of the most serious complications of diabetes is diabetic foot ulcer (DFU), which frequently creates a significant financial strain on patients and lowers their quality of life. Up until now, there has been no curative therapy for DFU, only symptomatic relief or an interruption in the disease's progression. Recent studies have focused attention on mesenchymal stem cells (MSCs), which provide innovative and potential treatment candidates for several illnesses as they can differentiate into various cell types. They are mostly extracted from the placenta, adipose tissue, umbilical cord (UC), and bone marrow (BM). Regardless of their origin, they show comparable features and small deviations. Our goal is to investigate MSCs' therapeutic effects, application obstacles, and patient benefit strategies for DFU therapy.

Methodology

A comprehensive search was conducted using specific keywords relating to DFU, MSCs, and connected topics in the databases of Medline, Scopus, Web of Science, and PubMed. The main focus of the selection criteria was on English-language literature that explored the relationship between DFU, MSCs, and related factors.

Results and Discussion

Numerous studies are being conducted and have demonstrated that MSCs can induce re-epithelialization and angiogenesis, decrease inflammation, contribute to immunological modulation, and subsequently promote DFU healing, making them a promising approach to treating DFU. This review article provides a general snapshot of DFU (including clinical presentation, risk factors and etiopathogenesis, and conventional treatment) and discusses the clinical progress of MSCs in the management of DFU, taking into consideration the side effects and challenges during the application of MSCs and how to overcome these challenges to achieve maximum benefits.

Conclusion

The incorporation of MSCs in the management of DFU highlights their potential as a feasible therapeutic strategy. Establishing a comprehensive understanding of the complex relationship between DFU pathophysiology, MSC therapies, and related obstacles is essential for optimizing therapy outcomes and maximizing patient benefits.

Toward transplantation tolerance with adipose tissue-derived therapeutics

Solid organ and composite tissue allotransplanation have been widely applied to treat end-stage organ failure and massive tissue defects, respectively. Currently there are a lot of research endeavors focusing on induction of transplantation tolerance, to relieve the burden derived from long-term immunosuppressant uptake. The mesenchymal stromal cells (MSCs) have been demonstrated with potent immunomodulatory capacities and applied as promising cellular therapeutics to promote allograft survival and induce tolerance. As a rich source of adult MSCs, adipose tissue provides additional advantages of easy accessibility and good safety profile. In recent years, the stromal vascular fraction (SVF) isolated from adipose tissues following enzymatic or mechanical processing without in vitro culture and expansion has demonstrated immunomodulatory and proangiogenic properties. Furthermore, the secretome of AD-MSCs has been utilized in transplantation field as a potential "cell-free" therapeutics. This article reviews recent studies that employ these adipose-derived therapeutics, including AD-MSCs, SVF, and secretome, in various aspects of organ and tissue allotransplantation. Most reports validate their efficacies in prolonging allograft survival. Specifically, the SVF and secretome have performed well for graft preservation and pretreatment, potentially through their proangiogenic and antioxidative capacities. In contrast, AD-MSCs were suitable for peri-transplantation immunosuppression. The proper combination of AD-MSCs, lymphodepletion and conventional immunosuppressants could consistently induce donor-specific tolerance to vascularized composite allotransplants (VCA). For each type of transplantation, optimizing the choice of therapeutics, timing, dose, and frequency of administration may be required. Future progress in the application of adipose-derived therapeutics to induce transplantation tolerance will be further benefited by continued research into their mechanisms of action and the development of standardized protocols for isolation methodologies, cell culture, and efficacy evaluation.

Adverse events, side effects and complications in mesenchymal stromal cell-based therapies

Numerous clinical studies have shown a wide clinical potential of mesenchymal stromal cells (MSCs) application. However, recent experience has accumulated numerous reports of adverse events and side effects associated with MSCs therapy. Furthermore, the strategies and methods of MSCs therapy did not change significantly in recent decades despite the clinical impact and awareness of potential complications. An extended understanding of limitations could lead to a wider clinical implementation of safe cell therapies and avoid harmful approaches. Therefore, our objective was to summarize the possible negative effects observed during MSCs-based therapies. We were also aimed to discuss the risks caused by weaknesses in cell processing, including isolation, culturing, and storage. Cell processing and cell culture could dramatically influence cell population profile, change protein expression and cell differentiation paving the way for future negative effects. Long-term cell culture led to accumulation of chromosomal abnormalities. Overdosed antibiotics in culture media enhanced the risk of mycoplasma contamination. Clinical trials reported thromboembolism and fibrosis as the most common adverse events of MSCs therapy. Their delayed manifestation generally depends on the patient's individual phenotype and requires specific awareness during the clinical trials with obligatory inclusion in the patient' informed consents. Finally we prepared the safety checklist, recommended for clinical specialists before administration or planning of MSCs therapy.