Mesenchymal stem cells derived from human umbilical cord ameliorate ischemia/reperfusion-induced acute renal failure in rats

Advances in the Treatment of Kidney Disorders using Mesenchymal Stem Cells

Renal disease is a medical condition that poses a potential threat to the life of an individual and is related to substantial morbidity and mortality rates in clinical environments. The aetiology of this condition is influenced by multiple factors, and its incidence tends to increase with progressive aging. Although supportive therapy and kidney transplantation have potential advantages, they also have limitations in terms of mitigating the progression of KD. Despite significant advancements in the domain of supportive therapy, mortality rates in patients continue to increase. Due to their ability to self-renew and multidirectionally differentiate, stem cell therapy has been shown to have tremendous potential in the repair of the diseased kidney. MSCs (Mesenchymal stem cells) are a cell population that is extensively distributed and can be located in various niches throughout an individual's lifespan. The cells in question are characterised by their potential for indefinite replication and their aptitude for undergoing differentiation into fully developed cells of mesodermal origin under laboratory conditions. It is essential to emphasize that MSCs have demonstrated a favorable safety profile and efficacy as a therapeutic intervention for renal diseases in both preclinical as well as clinical investigations. MSCs have been found to slow the advancement of kidney disease, and this impact is thought to be due to their control over a number of physiological processes, including immunological response, tubular epithelial- mesenchymal transition, oxidative stress, renal tubular cell death, and angiogenesis. In addition, MSCs demonstrate recognised effectiveness in managing both acute and chronic kidney diseases via paracrine pathways. The proposal to utilise a therapy that is based on stem-cells as an effective treatment has been put forward in search of discovering novel therapies to promote renal regeneration. Preclinical researchers have demonstrated that various types of stem cells can provide advantages in acute and chronic kidney disease. Moreover, preliminary results from clinical trials have suggested that these interventions are both safe and well-tolerated. This manuscript provides a brief overview of the potential renoprotective effects of stem cell-based treatments in acute as well as chronic renal dysfunction. Furthermore, the mechanisms that govern the process of kidney regeneration induced by stem cells are investigated. This article will examine the therapeutic approaches that make use of stem cells for the treatment of kidney disorders. The analysis will cover various cellular sources that have been utilised, potential mechanisms involved, and the outcomes that have been achieved so far.

The influence of inflammation on the characteristics of adipose-derived mesenchymal stem cells (ADMSCs) and tissue repair capability in a hepatic injury mouse model

BACKGROUND

Mesenchymal stem cells (MSCs) are adult stem cells with self-renewal and multi-directional differentiation potential and possess the functions of immunomodulation, regulation of cell growth, and repair of damage. Over recent years, MSCs have been found to regulate the secretion of inflammatory factors and to exert regulatory effects on various lymphocytes in inflammatory states, and on the subsequent repair of tissue damage caused by inflammation. In the present study, we analyzed the effects of tissue inflammation on the characteristics of MSCs.

METHODS

Human fat derived from the infrapatellar fat pad (IPFP) of knees with differing degrees of inflammation was extracted from specimens derived from total knee arthroplasties. HE and immunohistochemical staining was performed to directly observe the evidence and degree of inflammation in human infrapatellar fat pad tissue in order to classify MSCs cells, by their origin, into highly inflamed and lowly inflamed groups, and to study the effect of tissue inflammation on cell acquisition rates via cellular counting data. Flow cytometry assays were performed to investigate the effect of tissue inflammation on MSC surface marker expression. Trilineage differentiation, including osteogenesis, adipogenesis, and chondrogenesis, was performed to assess the effect of tissue inflammation on the ability of MSCs to undergo directed differentiation. The effect of tissue inflammation on the ability of MSCs to proliferate was investigated via clone formation studies. RNA-sequencing was performed to evaluate the transcriptomes of MSCs derived from different areas of inflammation. The effect of tissue inflammation on tissue repair capacity and safety of MSCs was investigated via a murine model of acute liver injury.

RESULTS

The results of cell count data indicate that a high degree of tissue inflammation significantly decreases the acquisition rate of MSCs, and the proportion of CD34+ and CD146+ cells. The results of our trilineage differentiation assay show that a higher degree of inflammation decreases osteogenic differentiation and enhances adipogenic and chondrogenic differentiation of MSCs. However, these differences were not statistically significant. Clone formation assays indicate that the degree of tissue inflammation at the MSC source does not significantly affect the proliferative capacity of MSCs. The transcriptomes of MSCs remain relatively stable in fat pad tissues derived from both highly and lowly inflamed samples. The results of acute liver injury investigations in mice indicate that MSCs of high and low inflammatory tissue origin have no significant difference in their tissue repair capability.

CONCLUSIONS

High tissue inflammation at the source of MSCs reduces the acquisition rate of MSCs and the percentage of CD34+ and CD146+ cells acquisition. However, source tissue inflammation may not significantly affect trilineage differentiation potential and proliferative capacity of MSCs. Also, MSCs obtained from differing source degrees of inflammation retain stable and similar transcriptomic profile and are both safe and efficacious for tissue repair/regeneration without detectable differences.

Long-Term Effects of Severe Burns on the Kidneys: Research Advances and Potential Therapeutic Approaches

Burns are a seriously underestimated form of trauma that not only damage the skin system but also cause various complications, such as acute kidney injury (AKI). Recent clinical studies have shown that the proportion of chronic kidney diseases (CKD) in burn patients after discharge is significantly higher than that in the general population, but the mechanism behind this is controversial. The traditional view is that CKD is associated with hypoperfusion, AKI, sepsis, and drugs administered in the early stages of burns. However, recent studies have shown that burns can cause long-term immune dysfunction, which is a high-risk factor for CKD. This suggests that burns affect the kidneys more than previously recognized. In other words, severe burns are not only an acute injury but also a chronic disease. Neglecting to study long-term kidney function in burn patients also results in a lack of preventive and therapeutic methods being developed. Furthermore, stem cells and their exosomes have shown excellent comprehensive therapeutic properties in the prevention and treatment of CKD, making them increasingly the focus of research attention. Their engineering strategy further improved the therapeutic performance. This review will focus on the research advances in burns on the development of CKD, illustrating the possible mechanism of burn-induced CKD and introducing potential biological treatment options and their engineering strategies.

Therapeutic Effects of Stem Cells From Different Source on Renal Ischemia- Reperfusion Injury: A Systematic Review and Network Meta-analysis of Animal Studies

Objective: Although stem cell therapy for renal ischemia-reperfusion injury (RIRI) has made immense progress in animal studies, conflicting results have been reported by the investigators. Therefore, we aimed to systematically evaluate the effects of different stem cells on renal function of animals with ischemia-reperfusion injury and to compare the efficacies of stem cells from various sources. Methods: PubMed, Web of Science, Embase, Cochrane, CNKI, VIP, CBM, and WanFang Data were searched for records until April 2021. Two researchers independently conducted literature screening, data extraction, and literature quality evaluation. Results and conclusion: Seventy-two animal studies were included for data analysis. Different stem cells significantly reduced serum creatinine and blood urea nitrogen levels in the early and middle stages (1 and 7 days) compared to the negative control group, however there was no significant difference in the late stage among all groups (14 days); In the early stage (1 day), the renal histopathological score in the stem cell group was significantly lower than that in the negative control group, and there was no significant difference among these stem cells. In addition, there was no significant difference between stem cell and negative control in proliferation of resident cells, however, significantly less apoptosis of resident cells than negative control. In conclusion, the results showed that stem cells from diverse sources could improve the renal function of RIRI animals. ADMSCs and MDMSCs were the most-researched stem cells, and they possibly hold the highest therapeutic potential. However, the quality of evidence included in this study is low, and there are many risks of bias. The exact efficacy of the stem cells and the requirement for further clinical studies remain unclear.

Umbilical cord mesenchymal stem/stromal cells potential to treat organ disorders; an emerging strategy

Currently, mesenchymal stem/stromal cells (MSCs) have attracted growing attention in the context of cell-based therapy in regenerative medicine. Following the first successful procurement of human MSCs from bone marrow (BM), these cells isolation has been conducted from various origins, in particular, the umbilical cord (UC). Umbilical cord-derived mesenchymal stem/stromal cells (UC-MSCs) can be acquired by a non-invasive plan and simply cultured, and thereby signifies their superiority over MSCs derived from other sources for medical purposes. Due to their unique attributes, including self-renewal, multipotency, and accessibility concomitant with their immunosuppressive competence and lower ethical concerns, UC-MSCs therapy is described as encouraging therapeutic options in cell-based therapies. Regardless of their unique aptitude to adjust inflammatory response during tissue recovery and delivering solid milieu for tissue restoration, UC-MSCs can be differentiated into a diverse spectrum of adult cells (e.g., osteoblast, chondrocyte, type II alveolar, hepatocyte, and cardiomyocyte). Interestingly, they demonstrate a prolonged survival and longer telomeres compared with MSCs derived from other sources, suggesting that UC-MSCs are desired source to use in regenerative medicine. In the present review, we deliver a brief review of UC-MSCs isolation, expansion concomitantly with immunosuppressive activities, and try to collect and discuss recent pre-clinical and clinical researches based on the use of UC-MSCs in regenerative medicine, focusing on with special focus on in vivo researches.

Identify the role of Human Wharton's Jelly Mesenchymal Stem Cells in repairing injured uterine of rat

AIM

Maternal complications caused by the cesarean delivery inhibit the capability of preserving the uterus and subsequent fertility. However, successful restoration of the incisional scar continuously still remains a challenge. This work was to evaluate the repairing effect of Human Wharton's Jelly Mesenchymal Stem Cells (hWJ-MSC) on incisional scar of the uterine.

METHODS

Eighteen rats were randomly assigned into two groups and nine for each: one group injected with hWJ-MSC in phosphate buffer saline (PBS) and the other injected with PBS for comparison.

RESULTS

With hWJ-MSC in PBS injected, the uterine endometrium and myometrium with full-thickness injury were restored and the functionality was greatly improved in comparison with the group only with PBS injected.

CONCLUSION

The hWJ-MSC can repair the injured uterine effectively by promoting the uterine endometrium and myometrium cells proliferation and according to the chi-square analysis the pregnancy is improved.

Mechanism of Human Umbilical Cord Mesenchymal Stem Cells Derived-Extracellular Vesicle in Cerebral Ischemia-Reperfusion Injury

Mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) are implicated in cerebral ischemia reperfusion (I/R) injury process. In this study, after extraction and identification of human umbilical cord MSCs (HMCs)-derived EVs, I/R rat models were established and treated with HMC-EVs to measure pathological damage, apoptosis and inflammation in brain tissues. The differentially expressed microRNAs (miRs) in HMC-EVs and I/R rat tissues were screened. The downstream gene and pathways of miR-24 were analyzed. The gain- and loss-of function of miR-24 in HMC-EVs was performed in I/R rat models and hypoxia/reoxygenation (H/R) cell models. SH-SY5Y cells were subjected to hypoxia and biological behaviors were detected by MTT assay, colony formation experiment, EdU staining and Transwell assays, and cells were incubated with the inhibitors of downstream pathways. As expected, infarct size, brain tissue apoptosis and inflammation were decreased after HMC-EVs treatment. miR-24 overexpression in HMC-EVs reduced I/R injury, while miR-24 knockdown in HMC-EVs impaired the protective roles of HMC-EVs in I/R injury. HMC-EVs-carried miR-24 could target AQP4 to activate the P38 MAPK/ERK1/2/P13K/AKT pathway, and thus promoted the proliferation and migration of SH-SY5Y cells after H/R injury, which were reversed by LY294002 and PD98095. Taken together, HMC-EVs-carried miR-24 played protective roles in I/R injury, possibly by targeting AQP4 and activating the P38 MAPK/ERK1/2/P13K/AKT pathway. This study may offer novel perspective for I/R injury treatment.

Exploiting the Natural Properties of Extracellular Vesicles in Targeted Delivery towards Specific Cells and Tissues

Extracellular vesicles (EVs) are important mediators of intercellular communication that participate in many physiological/pathological processes. As such, EVs have unique properties related to their origin, which can be exploited for drug delivery applications in cell regeneration, immunosuppression, inflammation, cancer treatment or cardioprotection. Moreover, their cell-like membrane organization facilitates uptake and accumulation in specific tissues and organs, which can be exploited to improve selectivity of cargo delivery. The combination of these properties with the inclusion of drugs or imaging agents can significantly improve therapeutic efficacy and selectivity, reduce the undesirable side effects of drugs or permit earlier diagnosis of diseases. In this review, we will describe the natural properties of EVs isolated from different cell sources and discuss strategies that can be applied to increase the efficacy of targeting drugs or other contents to specific locations. The potential risks associated with the use of EVs will also be addressed.

The Effects of Platelet-Rich and Platelet-Poor Plasma on Biological Characteristics of BM-MSCs In Vitro

Platelet-rich plasma (PRP) and its byproduct platelet-poor plasma (PPP) are rich sources of cytokines in tissue damage repair. Bone marrow-derived mesenchymal stem cells (BM-MSCs) have received more and more attention for their ability to treat multiple diseases. The purpose of our study was to investigate the biologic action of PPP and PRP on BM-MSCs. The adipogenic potential of BM-MSCs revealed no obvious change, but the osteogenic ability of BM-MSCs was enhanced after treated with PRP. CCK8 assays and cell colony formation assays showed that PRP promoted cell proliferation, while this effect of PPP was not obvious. No obvious difference was found in cell cycle and apoptosis of BM-MSCs between PRP and PPP treatment. Expression of β-galactosidase, a biological marker of senescence, was decreased upon PRP treatment which indicated that PRP provided significant protection against cellular senescence. The migratory capacity of BM-MSCs was detected by scratch and transwell assays. The results indicated that PRP could affect the migration ability of BM-MSCs. From immunofluorescence detection and western blot, we demonstrated that the level of epithelial-mesenchymal transition-related proteins was changed and several pluripotency marker genes, including Sox2, Sall4, Oct4, and Nanog, were increased. Finally, the expression of the key signal pathway such as PI3K/AKT was examined. Our findings suggested that PRP promoted cell migration of BM-MSCs via stimulating the signaling pathway of PI3K/AKT.

Mesenchymal Stromal Cell Uses for Acute Kidney Injury-Current Available Data and Future Perspectives: A Mini-Review

There is growing evidence concerning the potential use of mesenchymal stromal cells (MSCs) for different tissue injuries. Initially, the intended physiological use of MSCs was due to their ability to differentiate and replace damaged cells. However, MSCs have multiple effects, including being able to significantly modulate immunological responses. MSCs are currently being tested for neurodegenerative diseases, graft vs. host disease, kidney injury, and other chronic unremitting tissue damage. Using MSCs in acute tissue damage is only now being studied. Acute kidney injury (AKI) is a common cause of morbidity and mortality. After the primary insult, overactivation of the immune system culminates in additional secondary potentially permanent kidney damage. MSCs have the potential to ameliorate the secondary damage, and recent studies have shed important light on their mechanisms of action. This article summarizes the basics of MSCs therapy, the newly discovered mechanisms of action, and their potential application in the setting of AKI.

Role and effect of vein-transplanted human umbilical cord mesenchymal stem cells in the repair of diabetic foot ulcers in rats

Diabetic foot ulcer (DFU) is one of diabetic complications, which is frequently present and tormented in diabetes mellitus. Most multipotent mesenchymal stromal cells (MSCs) are capable of immune evasion, providing an allogeneic, ready-to-use, cell product option for therapeutic applications. The beneficial effect of MSCs for the treatment of a variety of traumatic injuries, such as open wounds, has been extensively explored. In this study, a rat DFU model was used to simulate the pathophysiology of clinical patients and to investigate the localization of human umbilical cord mesenchymal stem cells (hUC-MSCs) after intravenous transplantation and its role in DFU healing, so as to evaluate the potential of hUC-MSCs in the treatment of DFU. The diabetic rat model was established by streptozotocin injection, which was used to create full-thickness foot dorsal skin wounds to mimic DFU by a 6-mm skin biopsy punch and a Westcott scissor. The hUC-MSCs were transplanted through femoral vein, and the ulcer cicatrization situation and the fate of hUC-MSCs were evaluated. Our data suggest that intravenously transplantated hUC-MSCs have the ability to migrate and locate to the wound tissue and are helpful to wound healing in DFU rats, partly by regulating inflammation, trans-differentiation and providing growth factors that promote angiogenesis, cell proliferation and collagen deposition. Herein, we demonstrate that hUC-MSC transplantation is able to accelerate DFU healing in rats and transplantation of exogenous stem cells may be a potential strategy for clinical application in DFUs.

Exosomes-carried microRNA-26b-5p regulates microglia M1 polarization after cerebral ischemia/reperfusion

Exosome and microRNAs (miRs) are implicated in ischemia/reperfusion (I/R) process. In this study, I/R mouse model was established, and exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs) were isolated, identified, and injected to I/R mice to observe nerve injury and microglia M1 polarization. The differentially expressed genes in I/R microglia from databases were analyzed, and miRs differentially expressed in exosomes-treated microglia were analyzed by microarray. miR-26b-5p expression in hUCMSCs was intervened. Besides, microglia was extracted and co-cultured with SH-SY5Y or PC12 cells in oxygen-glucose deprivation/reperfusion (OGD/R) models to simulate I/R in vivo. Additionally, Toll-like receptor (TLR) activator GS-9620 was added to microglia. Exosomes alleviated nerve injury and inhibited M1 polarization in microglia. After I/R modeling, CH25H expression in microglia was upregulated but decreased after exosome treatment. miR-26b-5p was upregulated in microglia after exosome treatment and could target CH25H. Reduction in exosomal miR-26b-5p reversed the effects of hUCMSCs-exos on microglia. TLR pathway was activated in microglia after I/R but exosomes prevented its activation. Exosomal miR-26b-5p could repress M1 polarization of microglia by targeting CH25H to inactivate the TLR pathway, so as to relieve nerve injury after cerebral I/R. This investigation may offer new approaches for I/R treatment.

Exosomes Derived From Mesenchymal Stem Cells Ameliorate Renal Ischemic-Reperfusion Injury Through Inhibiting Inflammation and Cell Apoptosis

This study aimed to investigate the underlying mechanism of mesenchymal stem cells (MSCs) on protection of renal ischemia reperfusion injury (IRI). Exosomes originated from MSCs (MSC-ex) were extracted according to the instructions of Total Exosome Isolation Reagent. Rats were divided into five groups: sham-operated, IRI, MSC, MSC-ex, and MSC-ex + RNAase group. MSCs or MSC-ex were injected via carotid artery. The renal function test and pathological detection were applied to determine the renoprotection of MSC-ex on IRI. Western blotting and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were conducted to examine the levels of apoptosis-related proteins and inflammatory cytokines. Our results revealed that MSC-derived exosomes attenuated renal dysfunction, histologic damage, and decreased apoptosis. The expression levels of inflammatory cytokines, such as interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), nuclear factor kappa B (NF-κB), and interferon gamma (IFN-γ), were decreased by the MSC-ex treatment. The expression levels of caspase-9, cleaved caspase-3, Bax, and Bcl-2 caused by IR were also inhibited by MSC-ex. MSC-ex + RNAase group shared the similar pattern of changes with IRI group, likely due to the ability of RNA hydrolase to eliminate the function of exosomes. Our results demonstrated that exosomes originating from MSCs have protective effects on IRI via inhibiting cell apoptosis and inflammatory responses. Out findings may provide a new insight into therapeutic mechanism of MSCs on renal IRI.

Therapeutic Properties of Mesenchymal Stem Cell on Organ Ischemia-Reperfusion Injury

The shortage of donor organs is a major global concern. Organ failure requires the transplantation of functional organs. Donor’s organs are preserved for variable periods of warm and cold ischemia time, which requires placing them into a preservation device. Ischemia and reperfusion damage the organs, due to the lack of oxygen during the ischemia step, as well as the oxidative stress during the reperfusion step. Different methodologies are developed to prevent or to diminish the level of injuries. Preservation solutions were first developed to maximize cold static preservation, which includes the addition of several chemical compounds. The next chapter of organ preservation comes with the perfusion machine, where mechanical devices provide continuous flow and oxygenation ex vivo to the organs being preserved. In the addition of inhibitors of mitogen-activated protein kinase and inhibitors of the proteasome, mesenchymal stem cells began being used 13 years ago to prevent or diminish the organ’s injuries. Mesenchymal stem cells (e.g., bone marrow stem cells, adipose derived stem cells and umbilical cord stem cells) have proven to be powerful tools in repairing damaged organs. This review will focus upon the use of some bone marrow stem cells, adipose-derived stem cells and umbilical cord stem cells on preventing or decreasing the injuries due to ischemia-reperfusion.

Mesenchymal Stem Cells-Potential Applications in Kidney Diseases

Mesenchymal stem cells constitute a pool of cells present throughout the lifetime in numerous niches, characteristic of unlimited replication potential and the ability to differentiate into mature cells of mesodermal tissues in vitro. The therapeutic potential of these cells is, however, primarily associated with their capabilities of inhibiting inflammation and initiating tissue regeneration. Owing to these properties, mesenchymal stem cells (derived from the bone marrow, subcutaneous adipose tissue, and increasingly urine) are the subject of research in the settings of kidney diseases in which inflammation plays the key role. The most advanced studies, with the first clinical trials, apply to ischemic acute kidney injury, renal transplantation, lupus and diabetic nephropathies, in which beneficial clinical effects of cells themselves, as well as their culture medium, were observed. The study findings imply that mesenchymal stem cells act predominantly through secreted factors, including, above all, microRNAs contained within extracellular vesicles. Research over the coming years will focus on this secretome as a possible therapeutic agent void of the potential carcinogenicity of the cells.

Systematic Exposition of Mesenchymal Stem Cell for Inflammatory Bowel Disease and Its Associated Colorectal Cancer

Mesenchymal stem cells (MSCs) therapy has been applied to a wide range of diseases with excessive immune response, including inflammatory bowel disease (IBD), owing to its powerful immunosuppression and its ability to repair tissue lesions. Different sources of MSCs show different therapeutic properties. Engineering managements are able to enhance the immunomodulation function and the survival of MSCs involved in IBD. The therapeutic mechanism of MSCs in IBD mainly focuses on cell-to-cell contact and paracrine actions. One of the promising therapeutic options for IBD can focus on exosomes of MSCs. MSCs hold promise for the treatment of IBD-associated colorectal cancer because of their tumor-homing function and chronic inflammation inhibition. Encouraging results have been obtained from clinical trials in IBD and potential challenges caused by MSCs therapy are getting solved. This review can assist investigators better to understand the research progress for enhancing the efficacy of MSCs therapy involved in IBD and CAC.

Applications of stem cell-derived exosomes in tissue engineering and neurological diseases

Exosomes are extracellular vesicles with diameters of 30-100 nm that are key for intercellular communication. Almost all types of cell, including dendritic cells, T cells, mast cells, epithelial cells, neuronal cells, adipocytes, mesenchymal stem cells, and platelets, can release exosomes. Exosomes are present in human body fluids, such as urine, amniotic fluid, malignant ascites, synovial fluid, breast milk, cerebrospinal fluid, semen, saliva, and blood. Exosomes have biological functions in immune response, antigen presentation, intercellular communication, and RNA and protein transfer. This review provides a brief overview of the origin, morphological characteristics, enrichment and identification methods, biological functions, and applications in tissue engineering and neurological diseases of exosomes.

Umbilical cord blood-mesenchymal stem cells and carvedilol reduce doxorubicin- induced cardiotoxicity: Possible role of insulin-like growth factor-1

In this study, we tried to demonstrate the effects of adding human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) to carvedilol in improving the doxorubicin- induced cardiotoxicity in rats. Rats were randomly divided into four groups: group 1: control group, group 2: doxorubicin untreated group, group 3: rats injected with doxorubicin and received carvedilol, and group 4: rats injected with doxorubicin and received carvedilol and stem cell-treated. Electrocardiography (ECG) was performed to assess cardiac function after animals were sacrificed. Cardiac muscle sections were examined histologically using H&E, Masson trichrome and immunohistochemically using caspase 3 immunostaining. The morphometric and statistical analysis was performed. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), insulin-like growth factor (IGF-1), and vascular endothelial growth factor (VEGF) were measured. We concluded that combination of hUCB-MSCs and carvedilol markedly improves histological and immunohistochemical structure of cardiac muscle fibers and restores cardiac function in doxorubicin- induced cardiotoxicity in rats.

Stem/Stromal Cells for Treatment of Kidney Injuries With Focus on Preclinical Models

Within the last years, the use of stem cells (embryonic, induced pluripotent stem cells, or hematopoietic stem cells), Progenitor cells (e.g., endothelial progenitor cells), and most intensely mesenchymal stromal cells (MSC) has emerged as a promising cell-based therapy for several diseases including nephropathy. For patients with end-stage renal disease (ESRD), dialysis or finally organ transplantation are the only therapeutic modalities available. Since ESRD is associated with a high healthcare expenditure, MSC therapy represents an innovative approach. In a variety of preclinical and clinical studies, MSC have shown to exert renoprotective properties, mediated mainly by paracrine effects, immunomodulation, regulation of inflammation, secretion of several trophic factors, and possibly differentiation to renal precursors. However, studies are highly diverse; thus, knowledge is still limited regarding the exact mode of action, source of MSC in comparison to other stem cell types, administration route and dose, tracking of cells and documentation of therapeutic efficacy by new imaging techniques and tissue visualization. The aim of this review is to provide a summary of published studies of stem cell therapy in acute and chronic kidney injury, diabetic nephropathy, polycystic kidney disease, and kidney transplantation. Preclinical studies with allogeneic or xenogeneic cell therapy were first addressed, followed by a summary of clinical trials carried out with autologous or allogeneic hMSC. Studies were analyzed with respect to source of cell type, mechanism of action etc.

Acute Kidney Injury as a Condition of Renal Senescence

Acute kidney injury (AKI), characterized by a sharp drop in glomerular filtration, continues to be a significant health burden because it is associated with high initial mortality, morbidity, and substantial health-care costs. There is a strong connection between AKI and mechanisms of senescence activation. After ischemic or nephrotoxic insults, a wide range of pathophysiological events occur. Renal tubular cell injury is characterized by cell membrane damage, cytoskeleton disruption, and DNA degradation, leading to tubular cell death by necrosis and apoptosis. The senescence mechanism involves interstitial fibrosis, tubular atrophy, and capillary rarefaction, all of which impede the morphological and functional recovery of the kidneys, suggesting a strong link between AKI and the progression of chronic kidney disease. During abnormal kidney repair, tubular epithelial cells can assume a senescence-like phenotype. Cellular senescence can occur as a result of cell cycle arrest due to increased expression of cyclin kinase inhibitors (mainly p21), downregulation of Klotho expression, and telomere shortening. In AKI, cellular senescence is aggravated by other factors including oxidative stress and autophagy. Given this scenario, the main question is whether AKI can be repaired and how to avoid the senescence process. Stem cells might constitute a new therapeutic approach. Mesenchymal stem cells (MSCs) can ameliorate kidney injury through angiogenesis, immunomodulation, and fibrosis pathway blockade, as well as through antiapoptotic and promitotic processes. Young umbilical cord–derived MSCs are better at increasing Klotho levels, and thus protecting tissues from senescence, than are adipose-derived MSCs. Umbilical cord–derived MSCs improve glomerular filtration and tubular function to a greater degree than do those obtained from adult tissue. Although senescence-related proteins and microRNA are upregulated in AKI, they can be downregulated by treatment with umbilical cord–derived MSCs. In summary, stem cells derived from young tissues, such as umbilical cord–derived MSCs, could slow the post-AKI senescence process.

Human Umbilical Cord MSC-Derived Exosomes Suppress the Development of CCl4-Induced Liver Injury through Antioxidant Effect

Mesenchymal stem cells (MSCs) have been increasingly applied into clinical therapy. Exosomes are small (30–100 nm in diameter) membrane vesicles released by different cell types and possess the similar functions with their derived cells. Human umbilical cord MSC-derived exosomes (hucMSC-Ex) play important roles in liver repair. However, the effects and mechanisms of hucMSC-Ex on liver injury development remain elusive. Mouse models of acute and chronic liver injury and liver tumor were induced by carbon tetrachloride (CCl₄) injection, followed by administration of hucMSC-Ex via the tail vein. Alleviation of liver injury by hucMSC-Ex was determined. We further explored the production of oxidative stress and apoptosis in the development of liver injury and compared the antioxidant effects of hucMSC-Ex with frequently used hepatic protectant, bifendate (DDB) in liver injury. hucMSC-Ex alleviated CCl₄-induced acute liver injury and liver fibrosis and restrained the growth of liver tumors. Decreased oxidative stress and apoptosis were found in hucMSC-Ex-treated mouse models and liver cells. Compared to bifendate (DDB) treatment, hucMSC-Ex presented more distinct antioxidant and hepatoprotective effects. hucMSC-Ex may suppress CCl₄-induced liver injury development via antioxidant potentials and could be a more effective antioxidant than DDB in CCl₄-induced liver tumor development.

Differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells into endometrial cells

BACKGROUND

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are a novel and promising strategy for tissue engineering because of their ability to differentiate into many cell types. We characterized the differentiation of WJ-MSCs into endometrial epithelial cell (EEC)-like and endometrial stromal cell (ESC)-like cells and assessed the effect of 17β-estradiol and 8-Br-cAMP on the differentiation system.

METHODS

WJ-MSCs were treated in two ways to differentiate into EEC-like and ESC-like cells respectively: cocultured with ESCs in control/differentiation medium (17β-estradiol, growth factors); and cultured in control/differentiation medium (8-Br-cAMP alone or 8-Br-cAMP plus 17β-estrogen and growth factors). Three signaling pathway inhibitors (SB203580, PD98059, H89) were used to investigate the mechanism of WJ-MSC differentiation into ESC-like cells. Immunofluorescence, western blot and flow cytometry analyses were used to analyze expression of epithelial markers and stromal cell markers. Enzyme-linked immunosorbent assays were used to test the production of secretory proteins associated with the differentiation of ESC-like cells.

RESULTS

17β-estradiol at 1 μM downregulated vimentin and CD13 and upregulated cytokeratin and CD9 proteins, promoting the differentiation of WJ-MSCs into EEC-like cells in the coculture system. 8-Br-cAMP at 0.5 mM upregulated vimentin and CD13 and downregulated CK and CD9, promoting the differentiation of WJ-MSCs into ESC-like cells. Prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) were upregulated and the protein kinase A (PKA) signaling pathway was activated, whereas extracellular signal-regulated (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) were not affected.

CONCLUSIONS

17β-estradiol at 1 μM is a good inducer for facilitating the differentiation of WJ-MSCs into EEC-like cells. 8-Br-cAMP plus estrogen and growth factors can induce the differentiation of WJ-MSCs into ESC-like cells. During the differentiation of WJ-MSCs into ESC-like cells, PRL and IGFBP1 were upregulated by the treatment and the PKA signaling pathway was activated, whereas ERK1/2 and p38 MAPK were not affected. These findings suggest a promising approach to the treatment of endometrial damage and other endometrial diseases and suggest new applications for WJ-MSCs in clinical practice.

Tissue engineering for urinary tract reconstruction and repair: Progress and prospect in China

Several urinary tract pathologic conditions, such as strictures, cancer, and obliterations, require reconstructive plastic surgery. Reconstruction of the urinary tract is an intractable task for urologists due to insufficient autologous tissue. Limitations of autologous tissue application prompted urologists to investigate ideal substitutes. Tissue engineering is a new direction in these cases. Advances in tissue engineering over the last 2 decades may offer alternative approaches for the urinary tract reconstruction. The main components of tissue engineering include biomaterials and cells. Biomaterials can be used with or without cultured cells. This paper focuses on cell sources, biomaterials, and existing methods of tissue engineering for urinary tract reconstruction in China. The paper also details challenges and perspectives involved in urinary tract reconstruction.

3,3'-Diindolylmethane stimulates exosomal Wnt11 autocrine signaling in human umbilical cord mesenchymal stem cells to enhance wound healing

Human umbilical cord-derived mesenchymal stem cells (hucMSCs) are suggested as a promising therapeutic tool in regenerative medicine, however, their efficacy requires improvement. Small molecules and drugs come up to be a convenient strategy in regulating stem cells fate and function. Here, we evaluated 3,3'-diindolylmethane (DIM), a natural small-molecule compound involved in the repairing effects of hucMSCs on a deep second-degree burn injury rat model. HucMSCs primed with 50 μM of DIM exhibited desirable repairing effects compared with untreated hucMSCs. DIM enhanced the stemness of hucMSCs, which was related to the activation of Wnt/β-catenin signaling. β-catenin inhibition impaired the healing effects of DIM-primed hucMSCs (DIM-hucMSCs) in vivo. Moreover, we demonstrated that DIM upregulated Wnt11 expression in hucMSC-derived exosomes. Wnt11 knockdown inhibited β-catenin activation and stemness induction in DIM-hucMSCs and abrogated their therapeutic effects in vivo. Thus, our findings indicate that DIM promotes the stemness of hucMSCs through increased exosomal Wnt11 autocrine signaling, which provides a novel strategy for improving the therapeutic effects of hucMSCs on wound healing.

Pre-incubation with hucMSC-exosomes prevents cisplatin-induced nephrotoxicity by activating autophagy

Background

The administration of cisplatin is limited due to its nephrotoxic side effects, and prevention of this nephrotoxicity of cisplatin is difficult. Mesenchymal stem cell (MSC)-derived exosomes have been implicated as a novel therapeutic approach for tissue injury. In this study, we demonstrated that the pretreatment of human umbilical cord MSC-derived exosomes (hucMSC-Ex) can prevent the development of cisplatin-induced renal toxicity by activation of autophagy in vitro and in vivo.

Methods

In vitro, rat renal tubular epithelial (NRK-52E) cells were pre-incubated with exosomes from hucMSC or HFL1 (human lung fibroblast cells; as control) for 30 min, and 3-methyladenine (an autophagic inhibitor) and rapamycin (an autophagic inducer) for 1 h before cisplatin treatment for 8 h, respectively. Cells were harvested for apoptosis assay, enzyme-linked immunosorbent assay (ELISA), Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). In vivo, we constructed cisplatin-induced acute kidney injury rat models. Prior to treatment with cisplatin for 0.5 h, hucMSC-Ex or HFL1-Ex were injected into the kidneys via the renal capsule. 3-methyladenine and rapamycin were injected under the kidney capsule before hucMSC-Ex. All animals were sacrificed at 3 days after cisplatin injection. Renal function, Luminex assay, tubular apoptosis and proliferation, and autophagy response were evaluated.

Results

hucMSC-Ex inhibited cisplatin-induced mitochondrial apoptosis and secretion of inflammatory cytokines in renal tubular epithelial cells in vitro. hucMSC-Ex increased the expression of the autophagic marker protein LC3B and the autophagy-related genes ATG5 and ATG7 in NRK-52E cells. Rapamycin mimicked the effects of hucMSC-Ex in protecting against cisplatin-induced renal injury, while the effects were abrogated by the autophagy inhibitor 3-methyladenine in the animals.

Conclusions

Our findings indicate that the activation of autophagy induced by hucMSC-Ex can effectively relieve the nephrotoxicity of cisplatin. Therefore, pre-treatment of hucMSC-Ex may be a new method to improve the therapeutic effect of cisplatin.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0463-4) contains supplementary material, which is available to authorized users.

Icariin combined with human umbilical cord mesenchymal stem cells significantly improve the impaired kidney function in chronic renal failure

At present, the main therapy for chronic renal failure (CRF) is dialysis and renal transplantation, but neither obtains satisfactory results. Human umbilical cord mesenchymal stem cells (huMSCs) are isolated from the fetal umbilical cord which has a high self-renewal and multi-directional differentiation potential. Icariin (ICA), a kidney-tonifying Chinese Medicine can enhance the multipotency of huMSCs. Therefore, this work seeks to employ the use of ICA-treated huMSCs for the treatment of chronic renal failure. Blood urea nitrogen and creatinine (Cr) analyses showed amelioration of functional parameters in ICA-treated huMSCs for the treatment of CRF rats at 3, 7, and 14 days after transplantation. ICA-treated huMSCs can obviously increase the number of cells in injured renal tissues at 3, 7, and 14 days after transplantation by optical molecular imaging system. Hematoxylin-eosin staining demonstrated that ICA-treated huMSCs reduced the levels of fibrosis in CRF rats at 14 days after transplantation. Superoxide dismutase and Malondialdehyde analyses showed that ICA-treated huMSCs reduced the oxidative damage in CRF rats. Moreover, transplantation with ICA-treated huMSCs decreased inflammatory responses, promoted the expression of growth factors, and protected injured renal tissues. Taken together, our findings suggest that ICA-treated huMSCs could improve the kidney function in CRF rats.

Exosomes from Human Umbilical Cord Mesenchymal Stem Cells: Identification, Purification, and Biological Characteristics

Our and other groups have discovered that mesenchymal stem cells (MSCs) derived exosomes are a novel therapeutical modality for many diseases. In this study, we summarized a method to extract and purify hucMSCs-exosomes using ultrafiltration and gradient centrifugation in our laboratory and proved that hucMSCs-exosomes prepared according to our procedure were stable and bioactive. Results showed that exosomes derived from hucMSC were 40~100 nm and CD9 and CD81 positive. Functionally, hucMSCs-exosomes promoted cell proliferation and protected against oxidative stress-induced cell apoptosis in vitro by activation of ERK1/2 and p38. Interestingly, UV exposure abrogated the regulatory roles of exosomes under oxidative stress, indicating that hucMSCs-exosomes may regulate cell growth and apoptosis by exosomal shuttle of RNA. Furthermore, cytokine profile analysis revealed that hucMSCs-exosomes contained high dose of IL-6, IL-8, and other cytokines. The established method is practical and efficient, which provides a basis for further evaluating the potential of hucMSCs-exosomes as therapeutic agents.

MicroRNA-146b, a Sensitive Indicator of Mesenchymal Stem Cell Repair of Acute Renal Injury

: The role of mesenchymal stem cells (MSCs) in kidney injury repair has been studied widely. However, the underlying molecular mechanism remains unclear. We profiled the altered microRNAs in renal tissues from cisplatin-induced acute kidney injury (AKI) rats treated with or without rat bone marrow MSCs (rMSCs). We observed that microRNA-146b (miR-146b) expression was considerably upregulated in renal tissues from AKI rats compared with that in healthy rats, and the expression decreased following MSC treatment after cisplatin administration. At the early stage of AKI, serum miR-146b levels exhibited a rapid increase that was even faster than that of two conventional renal function indexes: serum creatinine and blood urea nitrogen levels. Furthermore, the serum miR-146b levels in AKI patients were higher than those in healthy people. In vitro exposure to cisplatin also increased miR-146b expression in renal tubular epithelial cells (TECs). miR-146b knockdown protected renal TECs from cisplatin-induced apoptosis and promoted their proliferation. Moreover, ErbB4 was identified as a direct target of miR-146b, and miR-146b inhibition induced ErbB4 expression, resulting in enhanced proliferation of injured renal TECs. In addition, restoration by rMSCs could be controlled through ErbB4 downregulation. In conclusion, elevated miR-146b expression contributes to cisplatin-induced AKI, partly through ErbB4 downregulation. miR-146b might be an early biomarker for AKI, and miR-146b inhibition could be a novel strategy for AKI treatment.

SIGNIFICANCE

The present study found that microRNA-146b (miR-146b) might be a novel biomarker for acute kidney injury and an indicator for its recovery after treatment with mesenchymal stem cells (MSCs). The results showed that in acute kidney injury induced by cisplatin, miR-146b in serum increased more quickly than did the usual indexes of kidney injury and decreased with restoration of MSCs. In addition, inhibition of miR-146b could ameliorate the apoptosis induced by cisplatin and potentially improve the proliferation by freeing ErbB4 and its downstream proteins.

Study of the Effect of Route of Administration of Mesenchymal Stem Cells on Cisplatin-Induced Acute Kidney Injury in Sprague Dawley Rats

BACKGROUND AND OBJECTIVES

Mesenchymal stem cells (MSCs) have been shown to ameliorate cisplatin-induced acute kidney injury (AKI). The present study compares the efficacy of different routes of MSCs administration on kidney damage and regeneration after cisplatin-induced AKI.

METHODS

A single intraperitoneal injection of cisplatin (5 mg/kg) was used to induce AKI in 160 rats. MSCs (5×10⁶) were given by either intravenous, intra-arterial or kidney sub capsular injection one day after cisplatin injection. Suitable control groups were included. Rats were sacrificed at 4, 7, 11 and 30 days after cisplatin injection. Kidney function parameters, kidney tissue oxidative stress markers, and scoring for renal tissue injury, regeneration and chronicity were all determined.

RESULTS

MSCs by any routes were able to ameliorate kidney function deterioration and renal tissue damage induced by cisplatin. The overall results of the three routes were equal. Differences between the different routes in one parameter were transient and inconsistent with other parameters.

CONCLUSIONS

Changing the route of MSCs injection does not have a major influence on the outcome. Future evaluation should focus on differences between the routes of administration considering the long term safety.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Angiogenesis: Potencial Clinical Application

Mesenchymal stem cells (MSCs) are adult multipotent stem cells that are able to differentiate into multiple specialized cell types including osteocytes, adipocytes, and chondrocytes. MSCs exert different functions in the body and have recently been predicted to have a major clinical/therapeutic potential. However, the mechanisms of self-renewal and tissue regeneration are not completely understood. It has been shown that the biological effect depends mainly on its paracrine action. Furthermore, it has been reported that the secretion of soluble factors and the release of extracellular vesicles, such as exosomes, could mediate the cellular communication to induce cell-differentiation/self-renewal. This review provides an overview of MSC-derived exosomes in promoting angiogenicity and of the clinical relevance in a therapeutic approach.

Enhanced renoprotective effect of IGF-1 modified human umbilical cord-derived mesenchymal stem cells on gentamicin-induced acute kidney injury

The therapeutic action of umbilical cord-derived mesenchymal stem cells (UC-MSCs) against acute kidney injury (AKI) has been demonstrated by several groups. However, how to further enhance the renoprotective effect of UC-MSCs and improve the therapy effect, are still unclear. In this study, we mainly investigated whether insulin-like growth factor-1 (IGF-1)-modified UC-MSCs hold an enhanced protective effect on gentamicin-induced AKI in vivo. Our results indicated that the IGF-1 overexpression could enhance the therapeutic action of human UC-MSCs, and the AKI rats treated with IGF-1-overexpressed UC-MSCs (UC-MSCs-IGF-1) showed better recovery of biochemical variables in serum or urine associated with renal function, histological injury and renal apoptosis, compared with AKI rats treated with normal UC-MSCs. RNA microarray analysis indicated that some key genes in the signal pathways associated with anti-oxidation, anti-inflammatory, and cell migratory capacity were up-regulated in UC-MSCs-IGF-1, and the results were further confirmed with qPCR. Furthermore, a series of detection in vitro and in vivo indicated that the UC-MSCs-IGF-1 hold better anti-oxidation, anti-inflammatory, and cell migratory capacity for IGF-1 overexpression. Thus, our study indicated that enhancement of UC-MSCs bioactivities with IGF-1 overexpression could increase the UC-MSCs therapeutic potential and further developed a new therapeutic strategy for the treatment of AKI.

Improving the outcome of kidney transplantation by ameliorating renal ischemia reperfusion injury: lost in translation?

Kidney transplantation is the treatment of choice in patients with end stage renal disease. During kidney transplantation ischemia reperfusion injury (IRI) occurs, which is a risk factor for acute kidney injury, delayed graft function and acute and chronic rejection. Kidneys from living donors show a superior short- and long-term graft survival compared with deceased donors. However, the shortage of donor kidneys has resulted in expansion of the donor pool by using not only living- and brain death donors but also kidneys from donation after circulatory death and from extended criteria donors. These grafts are associated with an increased sensitivity to IRI and decreased graft outcome due to prolonged ischemia and donor comorbidity. Therefore, preventing or ameliorating IRI may improve graft survival. Animal experiments focus on understanding the mechanism behind IRI and try to find methods to minimize IRI either before, during or after ischemia. This review evaluates the different experimental strategies that have been investigated to prevent or ameliorate renal IRI. In addition, we review the current state of translation to the clinical setting. Experimental research has contributed to the development of strategies to prevent or ameliorate IRI, but promising results in animal studies have not yet been successfully translated to clinical use.

Intra-arterial catheter system to repeatedly deliver mesenchymal stem cells in a rat renal failure model

BACKGROUND

Mesenchymal stem cell therapy in renal failure is rarely used because of low rates of cell engraftment after systemic delivery. Repeated intra-arterial cell administration may improve results; however, no current delivery method permits repeated intra-arterial infusions in a rat model. In this study, we developed an intra-arterial delivery system for repeated stem cell infusion via the aorta, catheterizing the left femoral artery to the suprarenal aorta under fluoroscopic guidance in rats with adenosine-induced renal failure.

METHODS

First, we compared our intra-arterial catheter system (C group, n = 3) with tail vein injection (V group, n = 3) for engraftment efficacy, using mesenchymal stem cells from luciferase transgenic rats. Rats were infused with the cells and euthanized the following day; we performed cell-tracking experiments using a bioluminescence imaging system to assess the distribution of the infused cells. Second, we assessed the safety of the system over a 30-day period in a second group of six rats receiving infusions every 7 days.

RESULTS

Cells infused through our delivery system efficiently engrafted into the kidney, compared with peripheral venous infusion. In five of the six rats in the safety study, the delivery system remained patent for at least 9 days (range, 9-24 days). Complications became evident only after 10 days.

CONCLUSION

Our intra-arterial catheter system was effective in delivering cells to the kidney and permitted repeated injection of cells.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Relieve Acute Myocardial Ischemic Injury

This study is aimed at investigating whether human umbilical cord mesenchymal stem cell- (hucMSC-) derived exosomes (hucMSC-exosomes) have a protective effect on acute myocardial infarction (AMI). Exosomes were characterized under transmission electron microscopy and the particles of exosomes were further examined through nanoparticle tracking analysis. Exosomes (400 μg protein) were intravenously administrated immediately following ligation of the left anterior descending (LAD) coronary artery in rats. Cardiac function was evaluated by echocardiography and apoptotic cells were counted using TUNEL staining. The cardiac fibrosis was assessed using Masson's trichrome staining. The Ki67 positive cells in ischemic myocardium were determined using immunohistochemistry. The effect of hucMSC-exosomes on blood vessel formation was evaluated through tube formation and migration of human umbilical vein endothelial cells (EA.hy926 cells). The results indicated that ligation of the LAD coronary artery reduced cardiac function and induced cardiomyocyte apoptosis. Administration of hucMSC-exosomes significantly improved cardiac systolic function and reduced cardiac fibrosis. Moreover, hucMSC-exosomes protected myocardial cells from apoptosis and promoted the tube formation and migration of EA.hy926 cells. It is concluded that hucMSC-exosomes improved cardiac systolic function by protecting myocardial cells from apoptosis and promoting angiogenesis. These effects of hucMSC-exosomes might be associated with regulating the expression of Bcl-2 family.

HucMSC-Exosome Mediated-Wnt4 Signaling Is Required for Cutaneous Wound Healing

Mesenchymal stem cell-derived exosomes (MSC-Ex) play important roles in tissue injury repair, however, the roles of MSC-Ex in skin damage repair and its mechanisms are largely unknown. Herein, we examined the benefit of human umbilical cord MSC-derived exosome (hucMSC-Ex) in cutaneous wound healing using a rat skin burn model. We found that hucMSC-Ex-treated wounds exhibited significantly accelerated re-epithelialization, with increased expression of CK19, PCNA, collagen I (compared to collagen III) in vivo. HucMSC-Ex promoted proliferation and inhibited apoptosis of skin cells after heat-stress in vitro. We also discovered that Wnt4 was contained in hucMSC-Ex, and hucMSC-Ex-derived Wnt4 promoted β-catenin nuclear translocation and activity to enhance proliferation and migration of skin cells, which could be reversed by β-catenin inhibitor ICG001. In vivo studies confirmed that the activation of Wnt/β-catenin by hucMSC-Ex played a key role in wound re-epithelialization and cell proliferation. Furthermore, knockdown of Wnt4 in hucMSC-Ex abrogated β-catenin activation and skin cell proliferation and migration in vitro. The in vivo therapeutic effects were also inhibited when the expression of Wnt4 in hucMSC-Ex was interfered. In addition, the activation of AKT pathway by hucMSC-Ex was associated with the reduction of heat stress-induced apoptosis in rat skin burn model. Collectively, our findings indicate that exosome-delivered Wnt4 provides new aspects for the therapeutic strategy of MSCs in cutaneous wound healing. Stem Cells 2015;33:2158-2168.

Effect of human umbilical cord mesenchymal stem cells transplantation on nerve fibers of a rat model of endometriosis

Background

Endometriosis is a common, benign, oestrogen-dependent, chronic gynaecological disorder associated with pelvic pain and infertility. Some researchers have identified nerve fibers in endometriotic lesions in women with endometriosis. Mesenchymal stem cells (MSCs) have attracted interest for their possible use for both cell and gene therapies because of their capacity for self-renewal and multipotentiality of differentiation. We investigated how human umbilical cord-MSCs (hUC-MSCs) could affect nerve fibers density in endometriosis.

Materials and Methods

In this experimental study, hUC-MSCs were isolated from fresh human umbilical cord, characterized by flow cytometry, and then transplanted into surgically induced endometriosis in a rat model. Ectopic endometrial implants were collected four weeks later. The specimens were sectioned and stained immunohistochemically with antibodies against neurofilament (NF), nerve growth factor (NGF), NGF receptor p75 (NGFRp75), tyrosine kinase receptor-A (Trk-A), calcitonin gene-related peptide (CGRP) and substance P (SP) to compare the presence of different types of nerve fibers between the treatment group with the transplantation of hUC-MSCs and the control group without the transplantation of hUC-MSCs.

Results

There were significantly less nerve fibers stained with specific markers we used in the treatment group than in the control group (p<0.05).

Conclusion

MSC from human umbilical cord reduced nerve fiber density in the treatment group with the transplantation of hUC-MSCs.

Human umbilical cord mesenchymal stem cell exosomes enhance angiogenesis through the Wnt4/β-catenin pathway

Human umbilical cord mesenchymal stem cells (hucMSCs) and their exosomes have been considered as potential therapeutic tools for tissue regeneration; however, the underlying mechanisms are still not well understood. In this study, we isolated and characterized the exosomes from hucMSCs (hucMSC-Ex) and demonstrated that hucMSC-Ex promoted the proliferation, migration, and tube formation of endothelial cells in a dose-dependent manner. Furthermore, we demonstrated that hucMSC-Ex promoted wound healing and angiogenesis in vivo by using a rat skin burn model. We discovered that hucMSC-Ex promoted β-catenin nuclear translocation and induced the increased expression of proliferating cell nuclear antigen, cyclin D3, N-cadherin, and β-catenin and the decreased expression of E-cadherin. The activation of Wnt/β-catenin is critical in the induction of angiogenesis by hucMSC-Ex, which could be reversed by β-catenin inhibitor ICG-001. Wnt4 was delivered by hucMSC-Ex, and the knockdown of Wnt4 in hucMSC-Ex abrogated β-catenin nuclear translocation in endothelial cells. The in vivo proangiogenic effects were also inhibited by interference of Wnt4 expression in hucMSC-Ex. Taken together, these results suggest that hucMSC-Ex-mediated Wnt4 induces β-catenin activation in endothelial cells and exerts proangiogenic effects, which could be an important mechanism for cutaneous wound healing.

Portable and quantitative evaluation of stem cell therapy towards damaged hepatocytes

Stem cell therapy has recently emerged as a breakthrough technology to treat a variety of diseases.

Cell-based therapy for acute organ injury: preclinical evidence and ongoing clinical trials using mesenchymal stem cells

Critically ill patients often suffer from multiple organ failures involving lung, kidney, liver, or brain. Genomic, proteomic, and metabolomic approaches highlight common injury mechanisms leading to acute organ failure. This underlines the need to focus on therapeutic strategies affecting multiple injury pathways. The use of adult stem cells such as mesenchymal stem or stromal cells (MSC) may represent a promising new therapeutic approach as increasing evidence shows that MSC can exert protective effects following injury through the release of promitotic, antiapoptotic, antiinflammatory, and immunomodulatory soluble factors. Furthermore, they can mitigate metabolomic and oxidative stress imbalance. In this work, the authors review the biological capabilities of MSC and the results of clinical trials using MSC as therapy in acute organ injuries. Although preliminary results are encouraging, more studies concerning safety and efficacy of MSC therapy are needed to determine their optimal clinical use. (ANESTHESIOLOGY 2014; 121:1099-121).

Effect of preemptive treatment with human umbilical cord blood-derived mesenchymal stem cells on the development of renal ischemia-reperfusion injury in mice

Human umbilical cord blood-derived mesenchymal stem cells (HUCB-MSCs) have been studied in several models of immune-mediated disease because of their unique immunomodulatory properties. We hypothesized that HUCB-MSCs could suppress the inflammatory response in postischemic kidneys and attenuate early renal injury. In 8- to 10-wk-old male C57BL/6 mice, bilateral ischemia-reperfusion injury (IRI) surgery was performed, and 1 × 10(6) HUCB-MSCs were injected intraperitoneally 24 h before surgery and during reperfusion. Renal functional and histological changes, HUCB-MSC trafficking, leukocyte infiltration, and cytokine expression were analyzed. Renal functional decline and tubular injury after IRI were attenuated by HUCB-MSC treatment. PKH-26-labeled HUCB-MSCs trafficked into the postischemic kidney. Although numbers of CD45-positive leukocytes in the postischemic kidney were comparable between groups, the expression of interferon-γ in the postischemic kidney was suppressed by HUCB-MSC treatment. The rapid decrease in intrarenal VEGF after IRI was markedly mitigated by HUCB-MSC treatment. In inflammatory conditions simulated in a cell culture experiment, VEGF secretion from HUCB-MSCs was substantially enhanced. VEGF inhibitor abolished the renoprotective effect of HUCB-MSCs after IRI. Flow cytometry analysis revealed the decreased infiltration of natural killer T cells and increased number of regulatory T cells in postischemic kidneys. In addition, these effects of HUCB-MSCs on kidney infiltrating mononuclear cells after IRI were attenuated by VEGF inhibitor. HUCB-MSCs attenuated renal injury in mice in the early injury phase after IRI, mainly by humoral effects and secretion of VEGF. Our results suggest a promising role for HUCB-MSCs in the treatment of renal IRI.

The IL-6-STAT3 axis mediates a reciprocal crosstalk between cancer-derived mesenchymal stem cells and neutrophils to synergistically prompt gastric cancer progression

Emerging evidence indicate that mesenchymal stem cells (MSCs) affect tumor progression by reshaping the tumor microenvironment. Neutrophils are essential component of the tumor microenvironment and are critically involved in cancer progression. Whether the phenotype and function of neutrophils is influenced by MSCs is not well understood. Herein, we investigated the interaction between neutrophils and gastric cancer-derived MSCs (GC-MSCs) and explored the biological role of this interaction. We found that GC-MSCs induced the chemotaxis of neutrophils and protected them from spontaneous apoptosis. Neutrophils were activated by the conditioned medium from GC-MSCs with increased expression of IL-8, TNFα, CCL2, and oncostatin M (OSM). GC-MSCs-primed neutrophils augmented the migration of gastric cancer cells in a cell contact-dependent manner but had minimal effect on gastric cancer cell proliferation. In addition, GC-MSCs-primed neutrophils prompted endothelial cells to form tube-like structure in vitro. We demonstrated that GC-MSCs stimulated the activation of STAT3 and ERK1/2 pathways in neutrophils, which was essential for the functions of activated neutrophils. We further revealed that GC-MSCs-derived IL-6 was responsible for the protection and activation of neutrophils. In turn, GC-MSCs-primed neutrophils induced the differentiation of normal MSCs into cancer-associated fibroblasts (CAFs). Collectively, our results suggest that GC-MSCs regulate the chemotaxis, survival, activation, and function of neutrophils in gastric cancer via an IL-6–STAT3–ERK1/2 signaling cascade. The reciprocal interaction between GC-MSCs and neutrophils presents a novel mechanism for the role of MSCs in remodeling cancer niche and provides a potential target for gastric cancer therapy.

The regulation of inflammatory mediators in acute kidney injury via exogenous mesenchymal stem cells

Acute kidney injury (AKI) remains to be an independent risk factor for mortality and morbidity. Inflammation is believed to play a major role in the pathophysiology of AKI. Exogenous mesenchymal stem cells (MSCs) are now under extensive investigation as a potential therapy for AKI. Various preclinical studies indicated the beneficial effects of MSCs in alleviating renal injury and accelerating tissue repair. However the mechanisms responsible for these effects are incompletely understood. In the recent years, anti-inflammatory/immunoregulatory properties of MSCs have become one of the important issues in the treatment of AKI. This review will summarize the current literature on the regulation of inflammatory mediators via exogenous MSCs contributing to the recovery from AKI.

Human mesenchymal stem cells alter macrophage phenotype and promote regeneration via homing to the kidney following ischemia-reperfusion injury

Mesenchymal stem cells (MSCs) ameliorate injury and accelerate repair in many organs, including the kidney, although the reparative mechanisms and interaction with macrophages have not been elucidated. This study investigated the reparative potential of human bone marrow-derived MSCs and traced their homing patterns following administration to mice with ischemia-reperfusion (IR) injury using whole body bioluminescence imaging. The effect of MSCs on macrophage phenotype following direct and indirect coculture was assessed using qPCR. Human cytokine production was measured using multiplex arrays. After IR, MSCs homed to injured kidneys where they afforded protection indicated by decreased proximal tubule kidney injury molecule-1 expression, blood urea nitrogen, and serum creatinine levels. SDS-PAGE and immunofluorescence labeling revealed MSCs reduced collagen α1(I) and IV by day 7 post-IR. Gelatin zymography confirmed that MSC treatment significantly increased matrix metalloproteinase-9 activity in IR kidneys, which contributed to a reduction in total collagen. Following direct and indirect coculture, macrophages expressed genes indicative of an anti-inflammatory "M2" phenotype. MSC-derived human GM-CSF, EGF, CXCL1, IL-6, IL-8, MCP-1, PDGF-AA, and CCL5 were identified in culture supernatants. In conclusion, MSCs home to injured kidneys and promote repair, which may be mediated by their ability to promote M2 macrophage polarization.

Mesenchymal stromal cell therapy in conditions of renal ischaemia/reperfusion

Acute kidney injury (AKI) represents a worldwide public health issue of increasing incidence, with a significant morbi-mortality. AKI treatment mostly relies on supportive manoeuvres in the absence of specific target-oriented therapy. The pathophysiology of AKI commonly involves ischaemia/reperfusion (I/R) events, which cause both immune and metabolic consequences in renal tissue. Similarly, at the time of kidney transplantation (KT), I/R is an unavoidable event which contributes to early graft dysfunction and enhanced graft immunogenicity. Mesenchymal stromal cells (MSCs) represent a heterogeneous population of adult, fibroblast-like multi-potent cells characterized by their ability to differentiate into tissues of mesodermal lineages. Because MSC have demonstrated immunomodulatory, anti-inflammatory and tissue repair properties, MSC administration at the time of I/R and/or at later times has been hypothesized to attenuate AKI severity and to accelerate the regeneration process. Furthermore, MSC in KT could help prevent both I/R injury and acute rejection, thereby increasing graft function and survival. In this review, summarizing the encouraging observations in animal models and in pilot clinical trials, we outline the benefit of MSC therapy in AKI and KT, and envisage their putative role in renal ischaemic conditioning.

In vitro differentiation of mesenchymal stem cells into mesangial cells when co-cultured with injured mesangial cells

Mesangial cells are one of the three major cell types of the kidney glomerulus that provide physical support for the glomerular capillary lumen of the kidney. Loss of mesangial cells due to pathologic conditions, such as glomerulonephritis and diabetic nephropathy, can impair renal function. Mesenchymal stem cells (MSC) are attractive candidates for kidney repair therapy since they can enhance recovery and protect against kidney failure. MSC can differentiate into mesangial cells in vivo. We have investigated the ability of MSC to differentiate into mesangial cells in vitro; they were co-cultured with oxidant-injured mesangial cells before being analysed by flow cytometry and for contractility. MSC co-cultured with injured mesangial cells had a mesangial cell-like morphology and contracted in response to angiotensin II. They expressed CD54(-) CD62E(+) in direct contrast to the CD54(+) CD62E(-) of pure MSC. In conclusion, MSC can differentiate into mesangial cells in vitro when co-cultured with injured mesangial cells.

Human unrestricted somatic stem cell administration fails to protect nude mice from cisplatin-induced acute kidney injury

BACKGROUND

Kidney failure is a debilitating disorder with limited treatment options. The kidney-protective effects of stem cells have been vastly investigated and promising results have been achieved with various sources of stem cells. However, in spite of beneficial effects on other disease models, the renoprotective potential of human cord blood-derived unrestricted somatic stem cells (USSC) has not been examined so far.

METHODS

In the present study, acute kidney failure was induced in female nude mice and the effect of USSC transplantation on kidney function and structure was assessed. Furthermore, the expression of some cytokine genes was examined by real-time PCR. Homing of the transplanted cells into kidneys was assessed by flow cytometry, immunohistochemistry, and real-time PCR.

RESULTS

USSC-conditioned medium did not attenuate the in vitro nephrotoxic effects of cisplatin. Transplantation of USSC to nude mice did not protect kidney function and was associated with worsened kidney structural damage. USSC transplantation was also associated with a decline in the renal expression of VEGF-A gene. In spite of these effects, the transplanted cells could not be detected in the kidneys by any of the exploited methods and they were mainly entrapped in the lungs.

CONCLUSION

These data indicate that USSC are not suitable for cell therapy in the setting of acute kidney injury. Also, this study shows that these stem cells are able to affect damaged kidneys even if they are not homed there.

Human umbilical cord mesenchymal stem cells attenuate cisplatin-induced acute and chronic renal injury

Mesenchymal stem cell is becoming a promising candidate in acute kidney injury (AKI). We first reported that human umbilical cord mesenchymal stem cells (hucMSCs) could ameliorate renal function in ischemic/reperfusion AKI rats, but the role of hucMSCs in cisplatin-induced acute and chronic injury has been demonstrated. More specifically, it is still unknown whether hucMSCs halt renal interstitial fibrosis. In this study, we investigated the effect of hucMSCs in cisplatin-induced kidney injury and explored the mechanism of action. Blood urea nitrogen (BUN) and creatinine (Cr) analyses showed amelioration of functional parameters in hucMSC-treated rats at early damage. Transplantation with hucMSCs promoted renal cell regeneration, inhibited cell apoptosis, abrogated inflammatory responses and protected mitochondria. Moreover, Masson's trichrome staining demonstrated reduced levels of fibrosis in kidney tissues of hucMSC-treated rats at six and eight weeks after cisplatin injection. These results were corroborated by reduced collagen deposit, the ratio of Bax to Bcl-2 and transforming growth factor β mRNA expression. Furthermore, hucMSCs prevented the epithelial-mesenchymal transition (EMT) in injury renal tissues, leading to the attenuation of chronic renal interstitial fibrosis. Taken together, our findings suggested that hucMSCs could decrease the kidney from development of later renal interstitial fibrosis by amelioration of early AKI.