Mesenchymal stem cells transplantation ameliorates glomerular injury in streptozotocin-induced diabetic nephropathy in rats via inhibiting macrophage infiltration

Bone marrow-derived c-kit positive stem cell administration protects against diabetes-induced nephropathy in a rat model by reversing PI3K/AKT/GSK-3β pathway and inhibiting cell apoptosis

Stem cell-based therapy has been proposed as a novel therapeutic strategy for diabetic nephropathy. This study was designed to evaluate the effect of systemic administration of rat bone marrow-derived c-kit positive (c-kit+) cells on diabetic nephropathy in male rats, focusing on PI3K/AKT/GSK-3β pathway and apoptosis as a possible therapeutic mechanism. Twenty-eight animals were randomly classified into four groups: Control group (C), diabetic group (D), diabetic group, intravenously received 50 μl phosphate-buffered saline (PBS) containing 3 × 105 c-kit- cells (D + ckit-); and diabetic group, intravenously received 50 μl PBS containing 3 × 105 c-Kit positive cells (D + ckit+). Control and diabetic groups intravenously received 50 μl PBS. C-kit+ cell therapy could reduce renal fibrosis, which was associated with attenuation of inflammation as indicated by decreased TNF-α and IL-6 levels in the kidney tissue. In addition, c-kit+ cells restored the expression levels of PI3K, pAKT, and GSK-3β proteins. Furthermore, renal apoptosis was decreased following c-kit+ cell therapy, evidenced by the lower apoptotic index in parallel with the increased Bcl-2 and decreased Bax and Caspase-3 levels. Our results showed that in contrast to c-kit- cells, the administration of c-kit+ cells ameliorate diabetic nephropathy and suggested that c-kit+ cells could be an alternative cell source for attenuating diabetic nephropathy.

Stem cells and exosomes: as biological agents in the diagnosis and treatment of polycystic ovary syndrome (PCOS)

A typical condition of the female reproductive system is polycystic ovary syndrome (PCOS). Hyperinsulinemia, insulin resistance, obesity, and hyperandrogenism are just a few of the metabolic abnormalities linked to this disease. Type 2 diabetes, hypertension, and cardiovascular disease are further issues related to PCOS. One consequence of this syndrome for which numerous treatment procedures have been developed is infertility. Metformin and clomiphene, two common allopathic medications used to treat PCOS, both have drawbacks and are ineffective. It is vital to seek novel therapeutic modalities to address these constraints. Exosomes (EXOs) are a particular class of extracellular vesicles that cells release, and they are known to play a significant role in mediating intercellular communication. A wide range of cargo, including lipids, proteins, mRNA, miRNAs, and numerous other noncoding RNAs, are contained in the nanoscale lipid bilayer exosomes. The cytokine effects of stem cells and EXOs derived from them enable the defense against metabolic diseases like PCOS. Moreover, EXO microRNAs can potentially be employed as biomarkers in the detection and management of PCOS. In this study, the potential of stem cells and exosomes are specifically investigated in the diagnosis and treatment of PCOS as one of the diseases of the female reproductive system.

Safety and Preliminary Efficacy of Mesenchymal Stromal Cell (ORBCEL-M) Therapy in Diabetic Kidney Disease: A Randomized Clinical Trial (NEPHSTROM)

SIGNIFICANCE STATEMENT

Mesenchymal stromal cells (MSCs) may offer a novel therapy for diabetic kidney disease (DKD), although clinical translation of this approach has been limited. The authors present findings from the first, lowest dose cohort of 16 adults with type 2 diabetes and progressive DKD participating in a randomized, placebo-controlled, dose-escalation phase 1b/2a trial of next-generation bone marrow-derived, anti-CD362 antibody-selected allogeneic MSCs (ORBCEL-M). A single intravenous (iv) infusion of 80×10 6 cells was safe and well-tolerated, with one quickly resolved infusion reaction in the placebo group and no subsequent treatment-related serious adverse events (SAEs). Compared with placebo, the median annual rate of decline in eGFR was significantly lower with ORBCEL-M, although mGFR did not differ. The results support further investigation of ORBCEL-M in this patient population in an appropriately sized phase 2b study.

BACKGROUND

Systemic therapy with mesenchymal stromal cells may target maladaptive processes involved in diabetic kidney disease progression. However, clinical translation of this approach has been limited.

METHODS

The Novel Stromal Cell Therapy for Diabetic Kidney Disease (NEPHSTROM) study, a randomized, placebo-controlled phase 1b/2a trial, assesses safety, tolerability, and preliminary efficacy of next-generation bone marrow-derived, anti-CD362-selected, allogeneic mesenchymal stromal cells (ORBCEL-M) in adults with type 2 diabetes and progressive diabetic kidney disease. This first, lowest dose cohort of 16 participants at three European sites was randomized (3:1) to receive intravenous infusion of ORBCEL-M (80×10 6 cells, n =12) or placebo ( n =4) and was followed for 18 months.

RESULTS

At baseline, all participants were negative for anti-HLA antibodies and the measured GFR (mGFR) and estimated GFR were comparable between groups. The intervention was safe and well-tolerated. One placebo-treated participant had a quickly resolved infusion reaction (bronchospasm), with no subsequent treatment-related serious adverse events. Two ORBCEL-M recipients died during follow-up of causes deemed unrelated to the trial intervention; one recipient developed low-level anti-HLA antibodies. The median annual rate of kidney function decline after ORBCEL-M therapy compared with placebo did not differ by mGFR, but was significantly lower by eGFR estimated by the Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease equations. Immunologic profiling provided evidence of preservation of circulating regulatory T cells, lower natural killer T cells, and stabilization of inflammatory monocyte subsets in those receiving the cell therapy compared with placebo.

CONCLUSIONS

Findings indicate safety and tolerability of intravenous ORBCEL-M cell therapy in the trial's lowest dose cohort. The rate of decline in eGFR (but not mGFR) over 18 months was significantly lower among those receiving cell therapy compared with placebo. Further studies will be needed to determine the therapy's effect on CKD progression.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrial.gov NCT02585622 .

Investigating the potential of oncolytic viruses for cancer treatment via MSC delivery

Mesenchymal stem cells (MSCs) have attracted considerable interest as a promising approach for cancer treatment due to their ability to undergo tumor-trophic migration. MSCs possess the unique ability to selectively migrate to tumors, making them an excellent candidate for targeted delivery of oncolytic viruses (OVs) to treat isolated tumors and metastatic malignancies. OVs have attracted attention as a potential treatment for cancer due to their ability to selectively infect and destroy tumor cells while sparing normal cells. In addition, OVs can induce immunogenic cell death and contain curative transgenes in their genome, making them an attractive candidate for cancer treatment in combination with immunotherapies. In combination with MSCs, OVs can modulate the tumor microenvironment and trigger anti-tumor immune responses, making MSC-releasing OVs a promising approach for cancer treatment. This study reviews researches on the use of MSC-released OVs as a novel method for treating cancer. Video Abstract.

Amelioration of exosome and mesenchymal stem cells in rats infected with diabetic nephropathy by attenuating early markers and aquaporin-1 expression

Diabetic nephropathy (DN) is a prevalent diabetic microvascular condition. It is the leading cause of kidney disease in the advanced stages. There is no currently effective treatment available. This research aimed to investigate the curative potentials of exosomes isolated from mesenchymal stem cells affecting DN. This study was performed on 70 male adult albino rats. Adult rats were randomized into seven groups: Group I: Negative control group, Group II: DN group, Group III: Balanites treated group, Group IV: MSCs treated group, Group V: Exosome treated group, Group VI: Balanites + MSCs treated group and Group VII: Balanites + exosome treated group. Following the trial period, blood and renal tissues were subjected to biochemical, gene expression analyses, and histopathological examinations. Results showed that MDA was substantially increased, whereas TAC was significantly decreased in the kidney in the DN group compared to normal health rats. Undesired elevated values of MDA levels and a decrease in TAC were substantially ameliorated in groups co-administered Balanites aegyptiacae with MSCs or exosomes compared to the DN group. A substantial elevation in TNF-α and substantially diminished concentration of IGF-1 were noticed in DN rats compared to normal health rats. Compared to the DN group, the co-administration of Balanites aegyptiacae with MSCs or exosomes substantially improved the undesirable elevated values of TNF-α and IGF-1. Furthermore, in the DN group, the mRNA expression of Vanin-1, Nephrin, and collagen IV was significantly higher than in normal healthy rats. Compared with DN rats, Vanin-1, Nephrin, and collagen IV Upregulation were substantially reduced in groups co-administered Balanites aegyptiacae with MSCs or exosomes. In DN rats, AQP1 expression was significantly lower than in normal healthy rats. Furthermore, the groups co-administered Balanites aegyptiacae with MSCs or exosomes demonstrated a substantial increase in AQP1 mRNA expression compared to DN rats.

Therapeutic role of mesenchymal stem cells (MSCs) in diabetic kidney disease (DKD)

Findings of preclinical studies and recent phase I/II clinical trials have shown that mesenchymal stem cells (MSCs) play a significant role in the development of diabetic kidney disease (DKD). Thus, MSCs have attracted increasing attention as a novel regenerative therapy for kidney diseases. This review summarizes recent literature on the roles and potential mechanisms, including hyperglycemia regulation, anti-inflammation, anti-fibrosis, pro-angiogenesis, and renal function protection, of MSC-based treatment methods for DKD. This review provides novel insights into understanding the pathogenesis of DKD and guiding the development of biological therapies.

The therapeutic potential of Camel Wharton jelly mesenchymal stem cells (CWJ-MSCs) in canine chronic kidney disease model

Background

Chronic kidney disease (CKD) is a worldwide health problem that its incidence increases nowadays with the increase in the risk of environmental pollution. CKD can progress to end-stage renal disease (ESRD) which usually ends fatally. This study aimed to examine the therapeutic potential of Camel Wharton jelly-mesenchymal stem cells (CWJ-MSCs) in chronic kidney disease model induced in dogs.

Methods

CWJ-MSCs were injected directed to the kidney with ultrasonographic guidance in dogs with 5/6 nephrectomy to evaluate its therapeutic potency in such cases. Analysis of variance was applied in normally distributed quantitative variables while a non-parametric Mann–Whitney test was used for non-normally distributed quantitative variables.

Results

The serum urea and creatinine in the treated group were significantly decreased transferring dogs in the treated group from stage 3 to stage 2 CKD according to the IRIS staging system. Histopathology of renal tissue revealed improving CKD lesions by increasing regeneration of degenerated tubules, maintaining the integrity of glomeruli. New vascularization with blood vessels remodeling were common findings. Periodic acid Schiff stain of renal tissue showed the integrity of renal tubules and thickness of the glomerular basement membrane. Fibrosis of cortex and medulla was lower in the treated group than in the CKD model as monitored by Mallory’s trichrome stain (MTC). NGAL and KIM-1 genes expression were decreased while VEGF and EGF genes expression were increased indicating renal tissue repair.

Conclusions

CWJ-MSCs have a therapeutic potential in the CKD model induced in dogs.

Extracellular Vesicles Released from Stem Cells as a New Therapeutic Strategy for Primary and Secondary Glomerulonephritis

Current treatment of primary and secondary glomerulopathies is hampered by many limits and a significant proportion of these disorders still evolves towards end-stage renal disease. A possible answer to this unmet challenge could be represented by therapies with stem cells, which include a variety of progenitor cell types derived from embryonic or adult tissues. Stem cell self-renewal and multi-lineage differentiation ability explain their potential to protect and regenerate injured cells, including kidney tubular cells, podocytes and endothelial cells. In addition, a broad spectrum of anti-inflammatory and immunomodulatory actions appears to interfere with the pathogenic mechanisms of glomerulonephritis. Of note, mesenchymal stromal cells have been particularly investigated as therapy for Lupus Nephritis and Diabetic Nephropathy, whereas initial evidence suggest their beneficial effects in primary glomerulopathies such as IgA nephritis. Extracellular vesicles mediate a complex intercellular communication network, shuttling proteins, nucleic acids and other bioactive molecules from origin to target cells to modulate their functions. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, reparative and immunomodulatory properties of parental cells and are increasingly recognized as a cell-free alternative to stem cell-based therapies for different diseases including glomerulonephritis, also considering the low risk for potential adverse effects such as maldifferentiation and tumorigenesis. We herein summarize the renoprotective potential of therapies with stem cells and extracellular vesicles derived from progenitor cells in glomerulonephritis, with a focus on their different mechanisms of actions. Technological progress and growing knowledge are paving the way for wider clinical application of regenerative medicine to primary and secondary glomerulonephritis: this multi-level, pleiotropic therapy may open new scenarios overcoming the limits and side effects of traditional treatments, although the promising results of experimental models need to be confirmed in the clinical setting.

Administration of mesenchymal stem cells in diabetic kidney disease: mechanisms, signaling pathways, and preclinical evidence

Diabetic kidney disease (DKD) is a serious microvascular complication of diabetes. Currently, the prevalence and mortality of DKD are increasing annually. However, with no effective drugs to prevent its occurrence and development, the primary therapeutic option is to control blood sugar and blood pressure. Therefore, new and effective drugs/methods are imperative to prevent the development of DKD in patients with diabetes. Mesenchymal stem cells (MSCs) with multi-differentiation potential and paracrine function have received extensive attention as a new treatment option for DKD. However, their role and mechanism in the treatment of DKD remain unclear, and clinical applications are still being explored. Given this, we here provide an unbiased review of recent advances in MSCs for the treatment of DKD in the last decade from the perspectives of the pathogenesis of DKD, biological characteristics of MSCs, and different molecular and signaling pathways. Furthermore, we summarize information on combination therapy strategies using MSCs. Finally, we discuss the challenges and prospects for clinical application.

Stem cell-derived and circulating exosomal microRNAs as new potential tools for diabetic nephropathy management

BACKGROUND

Despite major advances in the treatment of diabetic nephropathy (DN) in recent years, it remains the most common cause of end-stage renal disease. An early diagnosis and therapy may slow down the DN progression. Numerous potential biomarkers are currently being researched. Circulating levels of the kidney-released exosomes and biological molecules, which reflect the DN pathology including glomerular and tubular dysfunction as well as mesangial expansion and fibrosis, have shown the potential for predicting the occurrence and progression of DN. Moreover, many experimental therapies are currently being investigated, including stem cell therapy and medications targeting inflammatory, oxidant, or pro-fibrotic pathways activated during the DN progression. The therapeutic potential of stem cells is partly depending on their secretory capacity, particularly exosomal microRNAs (Exo-miRs). In recent years, a growing line of research has shown the participation of Exo-miRs in the pathophysiological processes of DN, which may provide effective therapeutic and biomarker tools for DN treatment.

METHODS

A systematic literature search was performed in MEDLINE, Scopus, and Google Scholar to collect published findings regarding therapeutic stem cell-derived Exo-miRs for DN treatment as well as circulating Exo-miRs as potential DN-associated biomarkers.

FINDINGS

Glomerular mesangial cells and podocytes are the most important culprits in the pathogenesis of DN and, thus, can be considered valuable therapeutic targets. Preclinical investigations have shown that stem cell-derived exosomes can exert beneficial effects in DN by transferring renoprotective miRs to the injured mesangial cells and podocytes. Of note, renoprotective Exo-miR-125a secreted by adipose-derived mesenchymal stem cells can improve the injured mesangial cells, while renoprotective Exo-miRs secreted by adipose-derived stem cells (Exo-miR-486 and Exo-miR-215-5p), human urine-derived stem cells (Exo-miR-16-5p), and bone marrow-derived mesenchymal stem cells (Exo-miR-let-7a) can improve the injured podocytes. On the other hand, clinical investigations have indicated that circulating Exo-miRs isolated from urine or serum hold great potential as promising biomarkers in DN.

The bi-directional effect of markers of inflammation and a decrease in glomerular filtration rate in chronic kidney disease

The aim of the study was to analyze and evaluate the relationship between the cytokine profile, C-reactive blood protein, fibrinogen, and glomerular filtration rate in patients with chronic kidney disease. The study involved individuals (n = 816) with chronic kidney disease (CKD) from the 1st to 5th stage of the disease, aged 20 to 76 years. The male to female ratio was 48% and 52%, respectively. All examined individuals underwent a comprehensive clinical and laboratory study evaluating the concentration of interleukins (IL, IL-10, IL-6, TNF-α) and acute phase inflammation proteins (C-reactive protein, fibrinogen) in the blood. CKD categories were evaluated by glomerular filtration rate (GFR), which was calculated using the CKD-EPI formula (Chronic Kidney Disease Epidemiology Collaboration). In individuals with CKD, significantly high concentrations of IL-10 and IL-6 were observed at stage 3b of the disease. Systolic blood pressure, median TNF-α, blood fibrinogen, and the number of individuals with high CRP were significant at stage 4 of CKD. A statistically significant correlation was found between the estimated GFR with the level of IL-6, CRP, blood fibrinogen at the 2nd stage of the disease and the concentration of IL-10 at 3b and TNF-α at the 4th stage of CKD. At the initial stage of CKD, there is a significant relationship between a decrease in estimated GFR and an increase in the level of IL-6, IL-10, TNF-α, as well as an increase in CRP and blood fibrinogen, which becomes pronounced at stages 3b and 4 of CKD.

Synergistic effects of sinapic acid and ellagic acid ameliorate streptozotocin-induced diabetic nephropathy by inhibiting apoptosis, DNA damage, and structural deterioration in rats

INTRODUCTION

Diabetic nephropathy (DN), a global problem that threatens human health, is an important reason for chronic kidney disease and kidney failure. In our study, it was aimed to investigate the individual and combined effects of SA and EA in streptozotocin (STZ)-induced rats.

METHODS

The groups are as follows: Control, untreated diabetic, diabetic treated with Sinapic acid (SA), diabetic treated with Ellagic acid (EA), diabetic treated with SA and EA, treated with SA, treated with EA, and treated with SA and EA. Total kidney volume, total glomerulus volume, total filtration space volume, caspase-3, and 8-OHdG immunoreactivity, Malondialdehyde (MDA), Glutathione (GSH), Catalase (CAT), serum urea, and creatinine levels were evaluated by stereological, immunohistochemical, and biochemical methods.

RESULTS

The findings of the study showed that total kidney volume, total glomerulus volume, total filtration gap volume, caspase-3, and 8-OHdG immunoreactivity, MDA, serum urea, and creatinine levels significantly increased in the untreated diabetic group compared to the control group. Also, severe mesangial and glomerular enlargement, extracellular matrix accumulation, and glomerular and tubular basal membrane thickness were observed in the tubulointerstitial and glomerular of the diabetic rats. However, individual and combined treatments of SA and EA ameliorated these histological changes. Additionally, decreased GSH and CAT in the untreated diabetic group increased by SA and EA treatment.

CONCLUSIONS

The findings suggest that treatment of SA and EA prevent apoptosis and DNA damage and structural changes in STZ-induced DN. However, the combined treatment of SA and EA were more effective than their individual treatments in all parameters except serum urea and creatinine.

Impact of Human Umbilical Cord Blood Mononuclear Cells on Gentamicin-Induced Renal Injury and Genotoxicity in Rats

Background: Acute kidney injury (AKI), also known as acute renal failure (ARF), has received considerable critical attention in recent years. Gentamicin (GM) is an antibiotic whose prolonged use results in AKI with a high mortality rate.

Methods: Fifty adult female albino rats weighing 150–200 g were used. The animals were divided into five groups: the first group was the normal healthy control one, the second group received only 1 × 10⁶ HUCB mononuclear cells (MNCs)/rat by intravenous (iv) injection, the third diseased group was given GM 100 mg/kg for 10 consecutive days by intraperitoneal injections, the fourth preventive group received 1 × 10⁶ HUCB MNCs/rat by iv injection 24 h before gentamicin treatment, and the fifth treated group received 1 × 10⁶ HUCB MNCs/rat by iv injection 24 h after gentamicin treatment. After 1 week of treatment, blood samples were collected, and kidneys were removed for histopathological examination.

Results: Rats treated with HUCB MNCs in the treated group had a significant decrease in renal damage, low levels of biomarkers for nephrotoxicities such as serum creatinine and blood urea nitrogen, and low chromosomal aberrations compared to the diseased third group. The gene expression of KIM-1 and NGAL was decreased in response to HUCB treatment.

Conclusions: HUCB MNCs have a curative effect against AKI and gentamicin-induced genotoxicity owing to their regenerative property.

Human umbilical cord mesenchymal stem cells reduce oxidative damage and apoptosis in diabetic nephropathy by activating Nrf2

Background

Mesenchymal stem cells (MSCs) have a therapeutic effect on diabetic nephropathy (DN) but the underlying mechanism remains unclear. This study was conducted to investigate whether human umbilical cord-MSCs (hUCMSCs) can induce oxidative damage and apoptosis by activating Nrf2.

Methods

We used a type 2 diabetic rat model and a high-glucose and fat-stimulated human glomerular mesangial cell (hGMC) model. Western blotting, RT-qPCR, and TUNEL staining were performed on animal tissues and cultured cells. Nuclear expression of Nrf2 was detected in the renal tissue. Furthermore, Nrf2 siRNA was used to examine the effects of hUCMSCs on hGMCs. Finally, the effect of hUCMSCs on the Nrf2 upstream signalling pathway was investigated.

Results

After treatment with hUCMSCs, Nrf2 showed increased expression and nuclear translocation. After Nrf2-specific knockout in hGMCs, the protective effect of hUCMSCs on apoptosis induced by high-glucose and fat conditions was reduced. Activation of the PI3K signalling pathway may be helpful for ameliorating DN using hUCMSCs.

Conclusions

hUCMSCs attenuated renal oxidative damage and apoptosis in type 2 diabetes mellitus and Nrf2 activation is one of the important mechanisms of this effect. hUCMSCs show potential as drug targets for DN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02447-x.

Diabetic Kidney Disease Alters the Transcriptome and Function of Human Adipose-Derived Mesenchymal Stromal Cells but Maintains Immunomodulatory and Paracrine Activities Important for Renal Repair

Mesenchymal stem/stromal cells (MSCs) facilitate repair in experimental diabetic kidney disease (DKD). However, the hyperglycemic and uremic milieu may diminish regenerative capacity of patient-derived therapy. We hypothesized that DKD reduces human MSC paracrine function. Adipose-derived MSC from 38 participants with DKD and 16 control subjects were assessed for cell surface markers, trilineage differentiation, RNA sequencing (RNA-seq), in vitro function (coculture or conditioned medium experiments with T cells and human kidney cells [HK-2]), secretome profile, and cellular senescence abundance. The direction of association between MSC function and patient characteristics were also tested. RNA-seq analysis identified 353 differentially expressed genes and downregulation of several immunomodulatory genes/pathways in DKD-MSC versus Control-MSC. DKD-MSC phenotype, differentiation, and tube formation capacity were preserved, but migration was reduced. DKD-MSC with and without interferon-γ priming inhibited T-cell proliferation greater than Control-MSC. DKD-MSC medium contained higher levels of anti-inflammatory cytokines (indoleamine 2,3-deoxygenase 1 and prostaglandin-E2) and prorepair factors (hepatocyte growth factor and stromal cell-derived factor 1) but lower IL-6 versus control-MSC medium. DKD-MSC medium protected high glucose plus transforming growth factor-β-exposed HK-2 cells by reducing apoptotic, fibrotic, and inflammatory marker expression. Few DKD-MSC functions were affected by patient characteristics, including age, sex, BMI, hemoglobin A_1c, kidney function, and urine albumin excretion. However, senescence-associated β-galactosidase activity was lower in DKD-MSC from participants on metformin therapy. Therefore, while DKD altered the transcriptome and migratory function of culture-expanded MSCs, DKD-MSC functionality, trophic factor secretion, and immunomodulatory activities contributing to repair remained intact. These observations support testing of patient-derived MSC therapy and may inform preconditioning regimens in DKD clinical trials.

A systematic review and meta-analysis of cell-based interventions in experimental diabetic kidney disease

Regenerative, cell‐based therapy is a promising treatment option for diabetic kidney disease (DKD), which has no cure. To prepare for clinical translation, this systematic review and meta‐analysis summarized the effect of cell‐based interventions in DKD animal models and treatment‐related factors modifying outcomes. Electronic databases were searched for original investigations applying cell‐based therapy in diabetic animals with kidney endpoints (January 1998‐May 2019). Weighted or standardized mean differences were estimated for kidney outcomes and pooled using random‐effects models. Subgroup analyses tested treatment‐related factor effects for outcomes (creatinine, urea, urine protein, fibrosis, and inflammation). In 40 studies (992 diabetic rodents), therapy included mesenchymal stem/stromal cells (MSC; 61%), umbilical cord/amniotic fluid cells (UC/AF; 15%), non‐MSC (15%), and cell‐derived products (13%). Tissue sources included bone marrow (BM; 65%), UC/AF (15%), adipose (9%), and others (11%). Cell‐based therapy significantly improved kidney function while reducing injury markers (proteinuria, histology, fibrosis, inflammation, apoptosis, epithelial‐mesenchymal‐transition, oxidative stress). Preconditioning, xenotransplantation, and disease‐source approaches were effective. MSC and UC/AF cells had greater effect on kidney function while cell products improved fibrosis. BM and UC/AF tissue sources more effectively improved kidney function and proteinuria vs adipose or other tissues. Cell dose, frequency, and administration route also imparted different benefits. In conclusion, cell‐based interventions in diabetic animals improved kidney function and reduced injury with treatment‐related factors modifying these effects. These findings may aid in development of optimal repair strategies through selective use of cells/products, tissue sources, and dose administrations to allow for successful adaptation of this novel therapeutic in human DKD.

Human umbilical cord mesenchymal stem cells attenuate podocyte injury under high glucose via TLR2 and TLR4 signaling

AIMS

This research aimed to investigate the effects of high glucose (HG) on the innate immunity of podocytes and diabetic nephropathy (DN) mice via Toll like receptor (TLR) signaling, and explore the protective effectsof human umbilical cord mesenchymal stem cells (HUC-MSCs) on this process.

METHODS

HUC-MSCs obtained from human umbilical cord were cocultured with podocytes and transplanted into DN mice. Flow cytometry, CCK-8assay, ELISA, western blot analysis, periodicacid-schiff, masson, immunohistochemistry and immunofluorescence staining was used to detect the inflammation, TLR signaling, physical, biochemical and morphological parameters in podocytes and DN mice.

RESULTS

HG reduced the viability of podocytes, activated TLR2 and TLR4 signaling pathway and increased the expression of inflammatory cytokines such as IL-6, IL-1β, TNF-α, and MCP-1 in podocytes and DN mice. However, HUC-MSCs decreased the inflammation and restrained the TLR signaling pathway caused by HG in vitro and in vivo. Furthermore the rhHGF decreased the expression of TLR2 and TLR4 while the blockade of HGF increased the expression of TLR2 and TLR4 in podocytes.

CONCLUSIONS

HUC-MSCs have benefits to the podocytes under HG and the progression of DN by inhibiting TLR signaling pathway and depressing the inflammation. HUC-MSCs may be a therapeutic strategy for treating patients with DN.

Stromal-vascular fraction of adipose tissue as an alternative source of cellular material for regenerative medicine

Adipose tissue is the most convenient source of cellular material for regenerative medicine as it can be obtained in significant quantities via cosmetic liposuction, lipoaspiration of subcutaneous fat or by excision of fat deposits. Adipose tissue consists of adipocytes and cells, which are the part of the stromal-vascular fraction (SVF). Different cell populations can be isolated from SVF, among which the population of adipose tissue stem cells (adipose-derived stem cells, ADSC) is especially important for regenerative medicine. SVF can be obtained relatively easily from adipose tissue (adipose tissue is an alternative to bone marrow in terms of being a source of stem cells) and used to treat various pathologies. Recent studies show that SVF not only has a therapeutic effect similar to that of ADSC, but in some cases is even more effective. The article provides the analysis of the main methods of SVF obtainment, characteristics of SVF cellular composition, its potential for use in clinical medicine and its main advantages over other sources of cellular material, including­ ADSC cultured in vitro, for regenerative medicine. Keywords: adipocytes, adipose-derived stem cells, regenerative medicine, stromal-vascular fraction

Effect of combined therapy of mesenchymal stem cells with GLP-1 receptor agonist, exenatide, on early-onset nephropathy induced in diabetic rats

Diabetic nephropathy is the principal cause of end-stage renal failure and current interventions for its recession remains unsatisfactory. Mesenchymal stem cells (MSCs) hold an attractive source for renovating injured tissues. Unfortunately, limited self-renewal and migration capacity of MSCs after transplantation hinder their clinical applicability which demands a new policy for enhancing their biological functions. This study aimed to investigate whether the renoprotective potential of adipose-derived MSCs (ADMSCs) in diabetic rats could be promoted by exenatide, a glucagon-like peptide-1 (GLP-1) analogue. These effects were studied in type 2 diabetes mellitus rats which were administrated ADMSCs, exenatide or their combination four weeks post-induction. Four weeks later, renal function parameters were evaluated. To address the possible underlying mechanisms, parameters indicating glycolipid metabolism tolerance and oxidative stress biomarkers were assessed in renal tissues alongside evaluation of protein expression of tumor necrosis factor-alpha, transforming growth factor-beta1 and cleaved caspase-3. The results showed that the combined therapy had superior renoprotective effect as evident by significant improvement in kidney function and renal architecture changes through rebalancing of inflammatory, fibrotic and apoptotic markers. Based on these outcomes, ADMSCs with exenatide were supposed to effectively ameliorate diabetic renal dysfunction compared to ADMSCs solely, presenting a promise therapy for diabetic nephropathy with further clinical studies warranted to validate this effect.

Progress toward the Clinical Application of Mesenchymal Stromal Cells and Other Disease-Modulating Regenerative Therapies: Examples from the Field of Nephrology

Drawing from basic knowledge of stem-cell biology, embryonic development, wound healing, and aging, regenerative medicine seeks to develop therapeutic strategies that complement or replace conventional treatments by actively repairing diseased tissue or generating new organs and tissues. Among the various clinical-translational strategies within the field of regenerative medicine, several can be broadly described as promoting disease resolution indirectly through local or systemic interactions with a patient's cells, without permanently integrating or directly forming new primary tissue. In this review, we focus on such therapies, which we term disease-modulating regenerative therapies (DMRT), and on the extent to which they have been translated into the clinical arena in four distinct areas of nephrology: renovascular disease (RVD), sepsis-associated AKI (SA-AKI), diabetic kidney disease (DKD), and kidney transplantation (KTx). As we describe, the DMRT that has most consistently progressed to human clinical trials for these indications is mesenchymal stem/stromal cells (MSCs), which potently modulate ischemic, inflammatory, profibrotic, and immune-mediated tissue injury through diverse paracrine mechanisms. In KTx, several early-phase clinical trials have also tested the potential for ex vivo-expanded regulatory immune cell therapies to promote donor-specific tolerance and prevent or resolve allograft injury. Other promising DMRT, including adult stem/progenitor cells, stem cell-derived extracellular vesicles, and implantable hydrogels/biomaterials remain at varying preclinical stages of translation for these renal conditions. To date (2021), no DMRT has gained market approval for use in patients with RVD, SA-AKI, DKD, or KTx, and clinical trials demonstrating definitive, cost-effective patient benefits are needed. Nonetheless, exciting progress in understanding the disease-specific mechanisms of action of MSCs and other DMRT, coupled with increasing knowledge of the pathophysiologic basis for renal-tissue injury and the experience gained from pioneering early-phase clinical trials provide optimism that influential, regenerative treatments for diverse kidney diseases will emerge in the years ahead.

Administration of mesenchymal stem cells in diabetic kidney disease: a systematic review and meta-analysis

BACKGROUND

Mesenchymal stem cell (MSC) therapy shows great promise for diabetic kidney disease (DKD) patients. Research has been carried out on this topic in recent years. The main goals of this paper are to evaluate the therapeutic effects of MSCs on DKD through a meta-analysis and address the mechanism through a systematic review of the literature.

METHOD

An electronic search of the Embase, Cochrane Library, ISI Web of Science, PubMed, and US National Library of Medicine (NLM) databases was performed for all articles about MSC therapy for DKD, without species limitations, up to January 2020. Data were pooled for analysis with Stata SE 12.

RESULT

The MSC-treated group showed a large and statistically significant hypoglycemic effect at 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months, and 6 months. Total hypoglycemic effect was observed (SMD = - 1.954, 95%CI - 2.389 to - 1.519, p < 0.001; I² = 85.1%). The overall effects on serum creatinine (SCr) and blood urea nitrogen (BUN) were analyzed, suggesting that MSC decreased SCr and BUN and mitigated the impairment of renal function (SCr: SMD = - 4.838, 95%CI - 6.789 to - 2.887, p < 0.001; I² = 90.8%; BUN: SMD = - 4.912, 95%CI - 6.402 to - 3.422, p < 0.001; I² = 89.3%). Furthermore, MSC therapy decreased the excretion of urinary albumin. Fibrosis indicators were assessed, and the results showed that transforming growth factor-β, collagen I, fibronectin, and α-smooth muscle actin were significantly decreased in the MSC-treated group compared to the control group.

CONCLUSION

MSCs might improve glycemic control and reduce SCr, BUN, and urinary protein. MSCs can also alleviate renal fibrosis. MSC therapy might be a potential treatment for DKD.

The Multi-Therapeutic Role of MSCs in Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most common diabetes mellitus (DM) microvascular complications, which always ends with end-stage renal disease (ESRD). Up to now, as the treatment of DN in clinic is still complicated, ESRD has become the main cause of death in diabetic patients. Mesenchymal stem cells (MSCs), with multi-differentiation potential and paracrine function, have attracted considerable attention in cell therapy recently. Increasing studies concerning the mechanisms and therapeutic effect of MSCs in DN emerged. This review summarizes several mechanisms of MSCs, especially MSCs derived exosomes in DN therapy, including hyperglycemia regulation, anti-inflammatory, anti-fibrosis, pro-angiogenesis, and renal function protection. We also emphasize the limitation of MSCs application in the clinic and the enhanced therapeutic role of pre-treated MSCs in the DN therapy. This review provides balanced and impartial views for MSC therapy as a promising strategy in diabetic kidney disease amelioration.

Regenerative Medicine Perspectives in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common gynecologic endocrine disorder in women between the ages of 15 and 40, with uncertain etiology. It is mostly presented with hyperandrogenism and insulin resistance along with a variety of comorbidities that significantly reduce a patient's quality of life. Many disturbed metabolic pathways are correlated with PCOS. Moreover, it is evident that there is a strong genetic factor for PCOS. Indeed, several altered gene expressions have been found in PCOS subjects, but the exact genetic origins are still unclear. The major treatment options such as pharmacological treatments are to improve the symptoms. In addition, surgical procedures (Bariatric surgery and assisted reproductive technologies) can be used to treat some of the patient's complications and reduce their severity. Generally, using pharmacological agents for a long period of time can increase the risk of adverse effects. Moreover, surgical options may have high-risk consequences. Herein, there is an undeniable need for a different multidisciplinary approach to PCOS. Regenerative medicine with the help of stem cells can develop a worthy alternative approach for the treatment of PCOS. Furthermore, animal models can provide valuable knowledge of genetic alterations and metabolic pathway disturbances in PCOS. They can also be used for testing novel treatments in pre-clinical stages. Therein, the current knowledge of PCOS and investigation about the potential role of regenerative medicine in developing new and more efficient treatments for PCOS are summarized here.

The Utility of Exosomes in Diagnosis and Therapy of Diabetes Mellitus and Associated Complications

Diabetes mellitus and the associated complications are metabolic diseases with high morbidity that result in poor quality of health and life. The lack of diagnostic methods for early detection results in patients losing the best treatment opportunity. Oral hypoglycemics and exogenous insulin replenishment are currently the most common therapeutic strategies, which only yield temporary glycemic control rather than curing the disease and its complications. Exosomes are nanoparticles containing bioactive molecules reflecting individual physiological status, regulating metabolism, and repairing damaged tissues. They function as biomarkers of diabetes mellitus and diabetic complications. Considering that exosomes are bioactive molecules, can be obtained from body fluid, and have cell-type specificity, in this review, we highlight the multifold effects of exosomes in the pathology and therapy of diabetes mellitus and diabetic complications.

Concise review: current trends on applications of stem cells in diabetic nephropathy

Diabetic nephropathy, with high prevalence, is the main cause of renal failure in diabetic patients. The strategies for treating DN are limited with not only high cost but an unsatisfied effect. Therefore, the effective treatment of DN needs to be explored urgently. In recent years, due to their self-renewal ability and multi-directional differentiation potential, stem cells have exerted therapeutic effects in many diseases, such as graft-versus-host disease, autoimmune diseases, pancreatic diseases, and even acute kidney injury. With the development of stem cell technology, stem cell-based regenerative medicine has been tried to be applied to the treatment of DN. Related stem cells include embryonic stem cells, induced pluripotent stem cells, mesenchymal cells, and endothelial progenitor cells. Undoubtedly, stem cell transplantation has achieved certain results in the treatment of DN animal models. However, stem cell therapy still remains certain thorny issues during treatment. For instance, poor engraftment and limited differentiation of stem cells caused by the diabetic microenvironment, differentiation into unwanted cell lineages, and malignant transformation or genetic aberrations of stem cells. At present, various researches on the therapeutic effects of stem cells in DN with different opinions are reported and the specific mechanism of stem cells is still unclear. We review here the potential mechanism of stem cells as new therapeutic agents in the treatment of DN. Also, we review recent findings and updated information about not only the utilization of stem cells on DN in both preclinical and clinical trials but limitations and future expectations of stem cell-based therapy for DN.

Mesenchymal Stem Cell Therapy for Diabetic Kidney Disease: A Review of the Studies Using Syngeneic, Autologous, Allogeneic, and Xenogeneic Cells

Diabetic kidney disease (DKD) is a microvascular complication of diabetes mellitus (DM) and comprises multifactorial pathophysiologic mechanisms. Despite current treatment, around 30-40% of individuals with type 1 and type 2 DM (DM1 and DM2) have progressive DKD, which is the most common cause of end-stage chronic kidney disease worldwide. Mesenchymal stem cell- (MSC-) based therapy has important biological and therapeutic implications for curtailing DKD progression. As a chronic disease, DM may impair MSC microenvironment, but there is compelling evidence that MSC derived from DM1 individuals maintain their cardinal properties, such as potency, secretion of trophic factors, and modulation of immune cells, so that both autologous and allogeneic MSCs are safe and effective. Conversely, MSCs derived from DM2 individuals are usually dysfunctional, exhibiting higher rates of senescence and apoptosis and a decrease in clonogenicity, proliferation, and angiogenesis potential. Therefore, more studies in humans are needed to reach a conclusion if autologous MSCs from DM2 individuals are effective for treatment of DM-related complications. Importantly, the bench to bedside pathway has been constructed in the last decade for assessing the therapeutic potential of MSCs in the DM setting. Laboratory research set the basis for establishing further translation research including preclinical development and proof of concept in model systems. Phase I clinical trials have evaluated the safety profile of MSC-based therapy in humans, and phase II clinical trials (proof of concept in trial participants) still need to answer important questions for treating DKD, yet metabolic control has already been documented. Therefore, randomized and controlled trials considering the source, optimal cell number, and route of delivery in DM patients are further required to advance MSC-based therapy. Future directions include strategies to reduce MSC heterogeneity, standardized protocols for isolation and expansion of those cells, and the development of well-designed large-scale trials to show significant efficacy during a long follow-up, mainly in individuals with DKD.

Role of mesenchymal stem cells and their culture medium in alleviating kidney injury in rats diabetic nephropathy

Background

Diabetic nephropathy (DN) is considered as one of the most serious complications resulting from diabetes mellitus and end-stage of renal failure globally. Up to 40% of diabetic patients will develop DN. The involvement of mesenchymal stem cells (MSCs) in diabetic renal lesions management has been established in many animal models of DN. The aim is to evaluate the capability of MSCs and their culture medium (CM) to alleviate DN in streptozotocin (STZ)-induced diabetic rat model. Female albino rats were made diabetic and were further categorized into 4 subgroups of 15 each: DN group, DN group received fibroblasts, MSCs group received one dose of 1 × 106 cells of MSCs, and CM group received one dose of 500 μl of CM. In all groups, the treatment was delivered by intravenous injection (IV) into the tail vein.

Results

MSCs insinuated themselves into the injured kidney as detected by CD44 expression. Biochemical and histological results showed that MSCs and/or CM effectively attenuated DN manifestations in rat model through their possible anti-inflammatory (tumor necrosis factor-α and transforming growth factor-β1 were decreased), anti-apoptotic (Bcl2 was increased while Bax and caspases were decreased), and anti-oxidant role (malondialdehyde was decreased while glutathione and catalase were increased).

Conclusion

These results provide a potential therapeutic tool for DN management through the administration of the CM from MSCs that ameliorates the effects of diabetes. It is also possible to treat DN using CM alone thus avoiding cell transplantation.

Transplantation of adipose-derived mesenchymal stem cell sheets directly into the kidney suppresses the progression of renal injury in a diabetic nephropathy rat model

AIMS/INTRODUCTION

Adipose-derived mesenchymal stem cell (ASC) transplantation is a promising therapy for diabetic nephropathy (DN). However, intravascular administration of ASCs is associated with low engraftment in target organs. Therefore, we considered applying the cell sheet technology to ASCs. In this study, ASC sheets were directly transplanted into the kidneys of a DN rat model, and therapeutic consequences were analyzed.

MATERIALS AND METHODS

Adipose-derived mesenchymal stem cells were isolated from adipose tissues of 7-week-old enhanced green fluorescent protein rats, and ASC sheets were prepared using a temperature-responsive culture dish. A DN rat model was established from 5-week-old Spontaneously Diabetic Torii fatty rats. Seven-week-old DN rats (n = 21) were assigned to one of the following groups: sham-operated (n = 6); ASC suspension (6.0 × 106  cells/mL) administered intravenously (n = 7); six ASC sheets transplanted directly into the kidney (n = 8). The therapeutic effect of the cell sheets was determined based on urinary biomarker expression and histological analyses.

RESULTS

The ASC sheets survived under the kidney capsule of the DN rat model for 14 days after transplantation. Furthermore, albuminuria and urinary tumor necrosis factor-α levels were significantly lower in the ASC sheets transplanted directly into the kidney group than in the sham-operated and ASC suspension administered intravenously groups (P < 0.05). Histologically, the ASC sheets transplanted directly into the kidney group presented mild atrophy of the proximal tubule and maintained the renal tubular structure.

CONCLUSIONS

Transplantation of ASC sheets directly into the kidney improved transplantation efficiency and suppressed renal injury progression. Therefore, the ASC sheet technology might be a promising novel treatment for DN.

Mesenchymal stem cells modified with angiotensin-converting enzyme 2 are superior for amelioration of glomerular fibrosis in diabetic nephropathy

AIMS

This study aimed to detect the effect of angiotensin-converting enzyme (ACE) 2-modified mesenchymal stem cells (MSCs) on glomerular fibrosis in vitro and in vivo and investigate the underlying molecular mechanism.

METHODS

MSCs transduced with the ACE2 gene (MSCs-ACE2) were cocultured with glomerular mesangial cells (GMCs) following Ang II stimulation. MSCs-ACE2 were transplanted into streptozotocin-induced diabetic rats. Physical, biochemical and morphological parameters were measured, and fibrotic indicators and renin-angiotensin system (RAS) components in GMCs and kidney tissues were assessed.

RESULTS

The transduction efficiency of MSCs was as high as 85%. The modified MSCs secreted soluble ACE2 protein into the culture medium. After transplantation into rats with diabetes, MSCs-ACE2 targeted injured kidneys and enhanced local expression of ACE2. Compared with MSC treatment alone, MSC-ACE2 treatment was superior in reducing albuminuria and improving glomerulosclerosis. In vitro and in vivo, MSCs-ACE2 were more beneficial than MSCs alone in decreasing Ang II and increasing Ang1-7, thereby inhibiting the detrimental effects of Ang II accumulation by downregulating collagen I and fibronectin (FN) expression and inhibiting the transforming growth factor (TGF-β)/Smad pathway.

CONCLUSIONS

MSCs modified with ACE2 therapy have additional benefits to the progression of diabetic nephropathy (DN) by inhibiting renal RAS activation and reducing glomerular fibrosis.

The future of diabetic kidney disease management: what to expect from the experimental studies?

Diabetic kidney disease (DKD) is a major cause of end-stage renal disease. Intensive blood glucose and blood pressure control, particularly using inhibitors of the renin-angiotensin system, have long been mainstays of therapy in patients with DKD. Moreover, new anti-hyperglycemic drugs have recently shown renoprotective effects and this represents a major progress in the management of DKD. However, the risk of progression is still substantial and additional drugs are required. Recent preclinical studies have identified novel therapeutic targets that may optimize renoprotection in the near future. Besides strategies aimed to reduce oxidative stress and inflammation in the kidney, novel extra-renal approaches targeting stem cells, extracellular vesicles, and the microbiota are on the horizon with promising preclinical data. Herein, we will review these lines of research and discuss potential clinical applications. Given the poor yield of experimental studies in DKD in the past years, we will also discuss strategies to improve translation of preclinical research to humans.

Immunomodulatory and Regenerative Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Renal Diseases

Mesenchymal stem cells (MSCs) have immunomodulatory and regenerative effects in many organs, including the kidney. Emerging evidence has shown that the trophic effects from MSCs are mainly mediated by the paracrine mechanism rather than the direct differentiation of MSCs into injured tissues. These secretomes from MSCs include cytokines, growth factors, chemokines and extracellular vesicles (EVs) containing microRNAs, mRNAs, and proteins. Many research studies have revealed that secretomes from MSCs have potential to ameliorate renal injury in renal disease models, including acute kidney injury and chronic kidney disease through a variety of mechanisms. These trophic mechanisms include immunomodulatory and regenerative effects. In addition, accumulating evidence has uncovered the specific factors and therapeutic mechanisms in MSC-derived EVs. In this article, we summarize the recent advances of immunomodulatory and regenerative effects of EVs from MSCs, especially focusing on the microRNAs.

Human mesenchymal stromal cells broadly modulate high glucose-induced inflammatory responses of renal proximal tubular cell monolayers

BACKGROUND

Renal proximal tubular epithelial cells (RPTEC) are dysfunctional in diabetic kidney disease (DKD). Mesenchymal stromal cells (MSC) may modulate DKD pathogenesis through anti-inflammatory mediators. This study aimed to investigate the pro-inflammatory effect of extended exposure to high glucose (HG) concentration on stable RPTEC monolayers and the influence of MSC on this response.

METHODS

Morphologically stable human RPTEC/TERT1 cell monolayers were exposed to 5 mM and 30 mM (HG) D-glucose or to 5 mM D-glucose + 25 mM D-mannitol (MAN) for 5 days with sequential immunoassays of supernatants and end-point transcriptomic analysis by RNA sequencing. Under the same conditions, MSC-conditioned media (MSC-CM) or MSC-containing transwells were added for days 4-5. Effects of CM from HG- and MAN-exposed RPTEC/MSC co-cultures on cytokine secretion by monocyte-derived macrophages were determined.

RESULTS

After 72-80 h, HG resulted in increased RPTEC/TERT1 release of interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP)-1 and neutrophil gelatinase-associated lipocalin (NGAL). The HG pro-inflammatory effect was attenuated by concentrated (10×) MSC-CM and, to a greater extent, by MSC transwell co-culture. Bioinformatics analysis of RNA sequencing data confirmed a predominant effect of HG on inflammation-related mediators and biological processes/KEGG pathways in RPTEC/TERT1 stable monolayers as well as the non-contact-dependent anti-inflammatory effect of MSC. Finally, CM from HG-exposed RPTEC/MSC transwell co-cultures was associated with attenuated secretion of inflammatory mediators by macrophages compared to CM from HG-stimulated RPTEC alone.

CONCLUSIONS

Stable RPTEC monolayers demonstrate delayed pro-inflammatory response to HG that is attenuated by close proximity to human MSC. In DKD, this MSC effect has potential to modulate hyperglycemia-associated RPTEC/macrophage cross-talk.

Mesenchymal Stem Cells Reverse Diabetic Nephropathy Disease via Lipoxin A4 by Targeting Transforming Growth Factor β (TGF-β)/smad Pathway and Pro-Inflammatory Cytokines

BACKGROUND Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. Mesenchymal stem cells (MSCs) treatment has been proved to be effective in DN models by protecting renal function and preventing fibrosis. However, the underlying mechanism is unclear. Previous research indicated diabetes and associated complications may be attributed to failed resolution of inflammation, which is deliberately regulated by pro-resolving lipids, including lipoxins (LXs), resolvins (Rv) D and E series, protectins, and maresins. In this study, we monitored pro-resolving mediators in a DN model to explore the mechanism of MSCs treatment. MATERIAL AND METHODS The DN model was induced by STZ injection in SD rats. UPLC-MS/MS was performed to determine pro-resolving lipids in kidney tissue and serum of DN model before and after MSCs treatment, as well as in supernatants of HBZY-1-MSCs co-culture. RESULTS LXA4 was highly accumulated in renal tissue of DN rats with MSCs treatment; ex vivo, LXA4 was significantly increased in the supernatants of HBZY-1 cells co-cultured with MSCs in a high-glucose (HG) medium. Western blot analysis indicated that ALX/FPR2, the receptor of LXA4, was markedly expressed in renal tissue of the DN-MSC group and HBZY-1 after incubating with MSCs in HG. Intraperitoneal injection of LXA4 inhibited renal fibrosis by targeting TGF-ß/Smad signaling and downregulated serum TNF-alpha, IL-6, IL-8, and IFN-γ in DN rats. Notably, all the protective effects induced by MSCs or LXA4 were abolished by ALX/FRP2 blocking. CONCLUSIONS Our results demonstrate that MSCs intervention prevented DN procession via the LXA4-ALX/FPR2 axis, which inhibited glomerulosclerosis and pro-inflammatory cytokines, eventually contributing to kidney homeostasis.

Paracrine effect of mesenchymal stem cell as a novel therapeutic strategy for diabetic nephropathy

Diabetic nephropathy (DN) is a microvascular complication of diabetes mellitus (DM) and the main reason for end-stage renal diseases (ESRD). Based on the role of mesenchymal stem cells (MSCs) in regenerative medicine, the MSC therapy has been considered a promising strategy to ameliorate the progression of DN. In this article, we review the therapeutic potential of MSCs in DN, mainly involving MSC paracrine mechanism based on trophic factors and extracellular vesicles. Knowledge of mechanism underlying the therapeutic action of MSCs on DN can provide much needed new drug targets for this disease.

Investigation of mechanisms of mesenchymal stem cells for treatment of diabetic nephropathy via construction of a miRNA-TF-mRNA network

BACKGROUND

Recent studies have reported that mesenchymal stem cells (MSCs) exert therapeutic effects on the treatment of diabetic nephropathy (DN), but the underlying mechanisms remain unclear.

METHODS

A dataset GSE65561 was obtained from Gene Expression Omnibus (GEO) database, which contained four healthy control samples (group 1), four healthy controls samples co-cultured with MSCs (group 2), five DN samples (group 3) and five DN samples co-cultured with MSCs (group 4). The differentially expressed genes (DEGs) between group 3 vs. group 1 and group 4 vs. group 2 were constructed using Linear Models for Microarray (LIMMA) package package. Then, DAVID was used to analyze the functional enrichment of DEGs. Based on STRING database the protein-protein interaction (PPI) network was visualized by the Cytoscape plug-in CytoNCA. Besides, the hub miRNAs and transcription factors (TFs) regulating DEGs were predicted using Webgestalt.

RESULTS

Totally, 303 up-regulated and 88 down-regulated DEGs were shared in group 3 vs. group 1 and group 4 vs. group 2. Besides, the up-regulated DEGs were mainly enriched in 'translation' and 'translational elongation', while the down-regulated genes were only enriched in 'protein kinase activity'. RPS27A and RPLP0 had a higher degree in the PPI network and they were regulated by EIF3M. In addition, ETF1 was predicted to be an important gene, which was regulated by miR-150, miR-134 and EIF2S1.

CONCLUSIONS

RPS27A, RPLP0 and ETF1 may be potential targets for MSCs on the treatment of DN. Highlights RPS27A and RPLP0 may be important genes in the treatment of MSCs for DN. TF EIF3M may play a key role in the treatment of MSCs for DN. MiR-150 and miR-134 may be essential microRNAs in the treatment of MSCs for DN.

Mechanistic insights into the augmented effect of bone marrow mesenchymal stem cells and thiazolidinediones in streptozotocin-nicotinamide induced diabetic rats

This study was designed to assess whether the protective effects of bone marrow-derived mesenchymal stem cells (MSCs) against diabetes could be enhanced by pioglitazone (PIO), a PPARγ agonist. Combined MSCs and PIO treatments markedly improved fasting blood glucose, body weight, lipid profile levels, insulin level, insulin resistance, β cell function. Those protective effects also attenuated both pancreatic lesions and fibrosis in diabetic rats and decreased the depletion of pancreatic mediators of glycemic and lipid metabolism including peroxisome proliferator-activated receptor alpha (PPARα), PGC-1α, GLP-1 and IRS-2. Cardiac biogenesis of diabetic groups was also improved with MSCs and/or PIO treatments as reflected by the enhanced up-regulation of the expressions of cardiac IRS1, Glucose transporter 4, PGC-1, PPARα and CPT-1 genes and the down-regulated expression of lipogenic gene SREBP. The combination of MSCs and PIO also potentiated the decrease of abnormal myocardial pathological lesions in diabetic rats. Similarly, the inhibitory effects of MSCs on diabetic cardiac fibrosis and on the up regulations of TGF-β, collagen I and III gene expressions were partial but additive when combined with PIO. Therefore, combined therapy with PIO and BMCs transplantation could further potentiate the protective benefit of MSCs against diabetes and cardiac damage compared to MSCs monotherapy.

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.

Early intervention with mesenchymal stem cells prevents nephropathy in diabetic rats by ameliorating the inflammatory microenvironment

Diabetic nephropathy (DN) is a major complication of diabetes and represents the leading cause of end-stage renal disease. Mesenchymal stem cell (MSC) treatment has been demonstrated to be effective in DN models by reducing albuminuria and attenuating glomerular injury; however, limited in-depth understanding of the underlying mechanism and a lack of clinical trials hinders its clinical use. Additionally, most of these experimental studies were conducted on the advanced stage of nephropathy, which is difficult to reverse and consequently showed limited therapeutic efficacy. We sought to evaluate whether early intervention by MSCs has the potential to prevent DN onset and progression as well as protect kidney function when intravenously administered to rats with diabetes. Diabetes was induced in adult male SD rats by streptozotocin (STZ) injection (55 mg/kg, i.p.). The diabetic rats were injected with or without bone marrow-derived MSCs (5×10⁶ per rat), via tail vein at 2, 4, 5 and 7 weeks after diabetes onset. Fasting blood glucose (FBG), blood urea nitrogen (BUN) and serum creatinine (Scr) levels in serum samples and glycosuria (GLU), microalbumin (MAU), and albumin to creatinine ratio (ACR) in urine samples were determined. Renal pathology and immunohistochemistry (IHC) for CD68, MCP-1, fibronectin (FN), transforming growth factor-β (TGF-β) and pro-inflammatory cytokines were also performed. Expression levels of the above factors as well as interleukin-10 (IL-10), and epidermal growth factor (EGF) were assessed by qPCR and multiplex bead-based suspension array system, respectively. Additionally, MSC tracing in vivo was performed. Ex vivo, peritoneal macrophages were co-cultured with MSCs, and expression of inflammatory cytokines was detected as well. MSC treatment profoundly suppressed renal macrophage infiltration and inflammatory cytokine secretion in diabetic rats, resulting in prominently improved kidney histology, systemic homeostasis, and animal survival, although no significant effect on hyperglycemia was observed. Engrafted MSCs were primarily localized in deteriorated areas of the kidney and immune organs 48 h after infusion. MSC treatment upregulated serum anti-inflammatory cytokines IL-10 and EGF. Ex vivo, MSCs inhibited lipopolysaccharide (LPS)-stimulated rat peritoneal macrophage activation via the downregulation of inflammatory-related cytokines such as IL-6, MCP-1, tumor necrosis factor-α (TNF-α) and IL-1β. Our results demonstrated that early intervention with MSCs prevented renal injury via immune regulation in diabetic rats, which restored the homeostasis of the immune microenvironment, contributing to the prevention of kidney dysfunction and glomerulosclerosis.

Endothelial progenitor cells transplantation attenuated blood-brain barrier damage after ischemia in diabetic mice via HIF-1α

Background

Blood-brain barrier impairment is a major indicator of endothelial dysfunction in diabetes. Studies showed that endothelial progenitor cell (EPC) transplantation promoted angiogenesis and improved function recovery after hind limb ischemia in diabetic mice. The effect of EPC transplantation on blood-brain barrier integrity after cerebral ischemia in diabetic animals is unknown. The aim of this study is to explore the effect of EPC transplantation on the integrity of the blood-brain barrier after cerebral ischemia in diabetic mice.

Methods

EPCs were isolated by density gradient centrifugation and characterized by flow cytometry and immunostaining. Diabetes was induced in adult male C57BL/6 mice by a single injection of streptozotocin at 4 weeks before surgery. Diabetic mice underwent 90-minute transient middle cerebral artery occlusion surgery and received 1 × 10⁶ EPCs transplantation immediately after reperfusion. Brain infarct volume, blood-brain barrier permeability, tight junction protein expression, and hypoxia inducible factor-1α (HIF-1α) mRNA level were examined after treatment.

Results

We demonstrated that neurological deficits were attenuated and brain infarct volume was reduced in EPC-transplanted diabetic mice after transient cerebral ischemia compared to the controls (p < 0.05). Blood-brain barrier leakage and tight junction protein degradation were reduced in EPC-transplanted mice (p <0.05). EPCs upregulated HIF-1α expression while HIF-1α inhibitor PX-478 abolished the beneficial effect of EPCs.

Conclusions

We conclude that EPCs protected blood-brain barrier integrity after focal ischemia in diabetic mice through upregulation of HIF-1α signaling.

Mesenchymal Stem Cell-Based Therapies against Podocyte Damage in Diabetic Nephropathy

Injury to podocytes is an early event in diabetic nephropathy leading to proteinuria with possible progression to end-stage renal failure. The podocytes are unique and highly specialized cells that cover the outer layer of kidney ultra-filtration barrier and play an important role in glomerular function. In the past few decades, adult stem cells, such as mesenchymal stem cells (MSCs) with a regenerative and differentiative capacity have been extensively used in cell-based therapies. In addition to their capability for regeneration and differentiation, MSCs contributes to their milieu by paracrine action of a series of growth factors via antiapoptotic, mitogenic and other cytokine actions that actively participate in treatment of podocyte damage through prevention of podocyte effacement, detachment and apoptosis. It is hoped that novel stem cell-based therapies will be developed in the future to prevent podocyte injury, thereby reducing the burden of kidney disease.

Adipose-derived stem cells ameliorate renal interstitial fibrosis through inhibition of EMT and inflammatory response via TGF-β1 signaling pathway

Adipose-derived stem cells (ADSCs) have been successfully used to treat acute kidney injury or acute renal failure. However, the effect of ADSCs on treating renal interstitial fibrosis remains unknown. Here, we assessed the therapeutic efficacy of ADSCs on renal interstitial fibrosis induced by unilateral ureter obstruction (UUO) and explored the potential mechanisms. After 7days of UUO, rats were injected with ADSCs (5×10⁶) or vehicle via tail vein. We found that ADSCs administration significantly ameliorated renal interstitial fibrosis, the occurrence of epithelial-mesenchymal transition (EMT) and inflammatory response. Furthermore, ADSCs administration could inhibit the activation of transforming growth factor-β1 (TGF-β1) signaling pathway, which might play a crucial role in renal interstitial fibrosis of the UUO model rats. These results suggested that ADSCs treatment attenuates renal interstitial fibrosis possibly through inhibition of EMT and inflammatory response via TGF-β1 signaling pathway. Therefore, ADSCs may be an effective therapeutic strategy for the treatment of renal interstitial fibrosis.

Stem cell therapy: An emerging modality in glomerular diseases

The kidney has been considered a highly terminally differentiated organ with low proliferative potential and thus unlikely to undergo regeneration. Glomerular disease progresses to end-stage renal disease (ESRD), which requires dialysis or renal transplantation for better quality of life for patients with ESRD. Because of the shortage of implantable kidneys and complications such as immune rejection, septicemia and toxicity of immunosuppression, kidney transplantation remains a challenge. Therapeutic options available for glomerular disease include symptomatic treatment and strategies to delay progression. In an attempt to develop innovative treatments by promoting the limited capability of regeneration and repair after kidney injury and overcome the progressive pathological process that is uncontrolled with conventional treatment modalities, stem cell-based therapy has emerged as novel intervention due to its ability to inhibit inflammation and promote regeneration. Recent developments in cell therapy have demonstrated promising therapeutic outcomes in terms of restoration of renal structure and function. This review focuses on stem cell therapy approaches for the treatment of glomerular disease, including the various cell sources used and recent advances in preclinical and clinical studies.

Mesenchymal Stem Cells as Therapeutic Candidates for Halting the Progression of Diabetic Nephropathy

Mesenchymal stem cells (MSCs) possess pleiotropic properties that include immunomodulation, inhibition of apoptosis, fibrosis and oxidative stress, secretion of trophic factors, and enhancement of angiogenesis. These properties provide a broad spectrum for their potential in a wide range of injuries and diseases, including diabetic nephropathy (DN). MSCs are characterized by adherence to plastic, expression of the surface molecules CD73, CD90, and CD105 in the absence of CD34, CD45, HLA-DR, and CD14 or CD11b and CD79a or CD19 surface molecules, and multidifferentiation capacity in vitro. MSCs can be derived from many tissue sources, consistent with their broad, possibly ubiquitous distribution. This article reviews the existing literature and knowledge of MSC therapy in DN, as well as the most appropriate rodent models to verify the therapeutic potential of MSCs in DN setting. Some preclinical relevant studies are highlighted and new perspectives of combined therapies for decreasing DN progression are discussed. Hence, improved comprehension and interpretation of experimental data will accelerate the progress towards clinical trials that should assess the feasibility and safety of this therapeutic approach in humans. Therefore, MSC-based therapies may bring substantial benefit for patients suffering from DN.

Mesenchymal stem cells: a future experimental exploration for recession of diabetic nephropathy

BACKGROUND

The progresses made in stem cell therapy offer an innovative approach and exhibit great potential for the repair of damaged organs and tissues. This study was conducted with a view to find the mechanisms responsible for the effectiveness of bone marrow-derived mesenchymal stem cells (BM-MSCs) in the suppression of diabetes and experimentally-induced diabetic nephropathy.

METHODS

To realize this objective, diabetic and diabetic nephropathy subject groups that underwent MSC treatment were studied through numerous biochemistry and molecular genetics analyses.

RESULTS

The findings show that, relative to the control groups, the rats in the diabetic and diabetic nephropathy groups treated with stem cells infused with BM-MSCs showed a significant reversal in the levels of their insulin, glucose, heme-oxygenase-1 (HO-1) serum, and advanced glycation end product (AGEP). Moreover, BM-MSC therapy was also found to have a definite positive effect on the kidney functions. In addition, it also corresponded with a significant decrease in the availability of certain growth factors, namely the fibroblast growth factor (FGF), the platelet-derived growth factor (PDGF), and the transforming growth factor-β (TGF-β). BM-MSC treatment also improved the levels of expression of monocyte chemoatractant-1 (MCP-1) and interleukin-8 (IL-8) genes within kidney tissues. Lastly, the treatment recovered the organizational structure of the kidney and pancreas, a result demonstrated by a histopathological analysis. These results greatly coincide with those obtained through the biochemistry and molecular genetics analyses.

CONCLUSION

Treatment using BM-MSCs is determined to be definitely effective in cases of diabetes and diabetic nephropathy.

The Promise of Mesenchymal Stem Cell Therapy for Diabetic Kidney Disease

Diabetes mellitus (DM) commonly leads to progressive chronic kidney disease despite current best medical practice. The pathogenesis of diabetic kidney disease (DKD) involves a complex network of primary and secondary mechanisms with both intra-renal and systemic components. Apart from inhibition of the renin angiotensin aldosterone system, targeting individual pathogenic mediators with drug therapy has not, thus far, been proven to have high clinical value. Stem or progenitor cell therapies offer an alternative strategy for modulating complex disease processes through suppressing multiple pathogenic pathways and promoting pro-regenerative mechanisms. Mesenchymal stem cells (MSCs) have shown particular promise based on their accessibility from adult tissues and their diverse mechanisms of action including secretion of paracrine anti-inflammatory and cyto-protective factors. In this review, the progress toward clinical translation of MSC therapy for DKD is critically evaluated. Results from animal models suggest distinct potential for systemic MSC infusion to favourably modulate DKD progression. However, only a few early phase clinical trials have been initiated and efficacy in humans remains to be proven. Key knowledge gaps and research opportunities exist in this field. These include the need to gain greater understanding of in vivo mechanism of action, to identify quantifiable biomarkers of response to therapy and to define the optimal source, dose and timing of MSC administration. Given the rising prevalence of DM and DKD worldwide, continued progress toward harnessing the inherent regenerative functions of MSCs and other progenitor cells for even a subset of those affected has potential for profound societal benefits.

Bone Marrow-Derived Stem Cells: a Mixed Blessing in the Multifaceted World of Diabetic Complications

Diabetes is one of the main economic burdens in health care, which threatens to worsen dramatically if prevalence forecasts are correct. What makes diabetes harmful is the multi-organ distribution of its microvascular and macrovascular complications. Regenerative medicine with cellular therapy could be the dam against life-threatening or life-altering complications. Bone marrow-derived stem cells are putative candidates to achieve this goal. Unfortunately, the bone marrow itself is affected by diabetes, as it can develop a microangiopathy and neuropathy similar to other body tissues. Neuropathy leads to impaired stem cell mobilization from marrow, the so-called mobilopathy. Here, we review the role of bone marrow-derived stem cells in diabetes: how they are affected by compromised bone marrow integrity, how they contribute to other diabetic complications, and how they can be used as a treatment for these. Eventually, we suggest new tactics to optimize stem cell therapy.

Human mesenchymal stem cells alter the gene profile of monocytes from patients with Type 2 diabetes and end-stage renal disease

AIM

Macrophage infiltration contributes to the pathogenesis of Type 2 diabetes. Mesenchymal stem cells (MSCs) possess immunomodulatory properties, making them an ideal candidate for therapeutic intervention. This study investigated whether MSCs can modulate the phenotype of monocytes isolated from Type 2 diabetic patients with end-stage renal disease.

MATERIALS & METHODS

Monocytes from control (n = 4) and Type 2 diabetic patients with end-stage renal disease (n = 5) were assessed using flow cytometry and microarray profiling, following 48 h of co-culture with MSCs.

RESULTS

Control subjects had a greater proportion of CD14(++)CD16(-) monocytes while diabetic patients had a higher proportion of CD14(++)CD16(+) and CD14(+)CD16(++) monocytes. MSCs promoted the proliferation of monocytes isolated from diabetic patients, reduced HLA-DR expression in both groups and promoted the expression of anti-inflammatory genes.

CONCLUSION

MSC-derived factors alter the polarization of monocytes isolated from healthy and diabetic subjects toward an M2 phenotype.

Stromal vascular fraction: A regenerative reality? Part 1: Current concepts and review of the literature

Stromal Vascular Fraction (SVF) is a heterogeneous collection of cells contained within adipose tissue that is traditionally isolated using enzymes such as collagenase. With the removal of adipose cells, connective tissue and blood from lipoaspirate, comes the SVF, a mix including mesenchymal stem cells, endothelial precursor cells, T regulatory cells, macrophages, smooth muscle cells, pericytes and preadipocytes. In part 1 of our 2-part series, we review the literature with regards to the intensifying interest that has shifted toward this mixture of cells, particularly due to its component synergy and translational potential. Trials assessing the regenerative potential of cultured Adipose Derived Stem Cells (ADSCs) and SVF demonstrate that SVF is comparably effective in treating conditions ranging from radiation injuries, burn wounds and diabetes, amongst others. Aside from their use in chronic conditions, SVF enrichment of fat grafts has proven a major advance in maintaining fat graft volume and viability. Many SVF studies are currently in preclinical phases or are moving to human trials. Overall, regenerative cell therapy based on SVF is at an early investigative stage but its potential for clinical application is enormous.

Icariside II ameliorates diabetic nephropathy in streptozotocin-induced diabetic rats

Purpose

To investigate the therapeutic effects and potential mechanisms of icariside II (ICA II) on reversing diabetic nephropathy in streptozotocin (STZ)-induced type I diabetic rats.

Methods

Newborn male Sprague Dawley rats were labeled with thymidine analog 5-ethynyl-2-deoxyuridine (EdU) for tracking endogenous label retaining progenitor cells (LRCs). At age of 8 weeks, 48 rats were randomly divided into three groups: normal control group (n=16), diabetes mellitus group (DM; n=16), and diabetes mellitus plus ICA II therapy group (DM+ICA II, n=16). Eight weeks induced for diabetes with STZ, rats in DM group and DM+ICA II group were treated with vehicle or ICA II (5 mg/kg/day) for another 8 weeks, respectively. Then, blood creatinine, 24-hour urine protein, blood urea nitrogen, and glycosylated hemoglobin were measured, as well as the expression of von Willebrand factor, malondialdehyde, transforming growth factor-β/drosophila mothers against decapentaplegic protein/connective tissue growth factor (TGF-β/Smad/CTGF) signaling, marker of proliferation Ki-67, and EdU+ LRCs in renal tissues.

Results

Increased levels of creatinine, 24-hour urine protein, and blood urea nitrogen and remarkably decreased proportion of normal glomeruli and increased proportions of I, IIa, IIb, and III glomeruli were observed in diabetic rats, while ICA II could reverse these changes. Interestingly, ICA II could significantly downregulate the levels of malondialdehyde and TGF-β/Smad/CTGF signaling and increase the expression of von Willebrand factor, Ki-67, and EdU+ LRCs in the kidney.

Conclusion

ICA II treatment could ameliorate diabetic nephropathy in STZ-induced diabetic rats by increasing endothelial cell contents, downregulating TGF-β/Smad/CTGF signaling pathway and oxidative stress level, and promoting cell proliferation both in kidney cortex and medulla. These beneficial effects appear to be mediated by its antioxidant capacity and recruitment of endogenous EdU+ progenitor cells into the kidney tissue.

Trophic Factors from Tissue Stem Cells for Renal Regeneration

Stem cell therapies against renal injury have been advancing. The many trials for renal regeneration are reported to be effective in many kinds of renal injury models. Regarding the therapeutic mechanism, it is believed that stem cells contribute to make regeneration via not only direct stem cell differentiation in the injured space but also indirect effect via secreted factors from stem cells. Direct differentiation from stem cells to renal composed cells has been reported. They differentiate to renal composed cells and make functions. However, regarding renal regeneration, stem cells are discussed to secrete many kinds of growth factors, cytokines, and chemokines in paracrine or autocrine manner, which protect against renal injury, too. In addition, it is reported that stem cells have the ability to communicate with nearby cells via microvesicle-related RNA and proteins. Taken together from many reports, many secreted factors from stem cells were needed for renal regeneration orchestrally with harmony. In this review, we focused on the effects and insights of stem cells and regenerative factors from stem cells.