Beneficial Effects of Systemically Administered Human Muse Cells in Adriamycin Nephropathy

Could hesperetin ameliorate doxorubicin-induced nephrotoxicity in rats via its antioxidant, antiapoptotic, and anti-inflammatory properties?

Doxorubicin (DOX), from the anthracycline family, is a widely utilized chemotherapy for various malignancies; however, its utility is limited due to the serious adverse reactions, particularly on the kidneys, primarily related to oxidative stress, inflammation, and apoptosis. Hesperetin (HES), the citrus fruit derivative, is a naturally occurring flavonoid. Previous studies underscored HES's protective efficacy against renal damage in several disorders in rodents through its proven antioxidant, antiapoptotic, and anti-inflammatory properties. This work explored the protecting role of HES against the nephrotoxic effects of DOX and the possible underlying mechanisms. Nephrotoxicity was induced in rats via administering six equal doses of DOX (3 mg/kg/week, i.p) for six consecutive weeks. The treated group received HES (50 mg/kg/day, p.o.) simultaneously with DOX. Rats' body and kidney weights, serum creatinine, blood urea nitrogen (BUN), and albumin were estimated. Kidney tissue was treated to assess redox status, histopathological, and immunohistochemical alterations. Compared to the controls, coadministration of HES with DOX significantly reduced the serum BUN and creatinine, elevated the serum albumin, amended the glomerular distortion and tubular epithelial degeneration, decreased collagen deposition, vascular congestion, and inflammatory cells in addition to the significant attenuation of inflammatory cytokines and proapoptotic markers. Our study is the first of its kind to underscore the HES's antioxidant, antiapoptotic, and anti-inflammatory activities in an experimental model of DOX-induced nephrotoxicity with emphasis on TNF-α, IL-1β, and IL-6 signaling pathway, rendering it as an effective therapeutic supplement that could alleviate the nephrotoxic effect of DOX.

Multilineage-differentiating stress-enduring cells attenuate the cognitive impairment caused by chronic cerebral hypoperfusion in rats

Multilineage-differentiating stress-enduring (Muse) cells are non-tumorigenic pluripotent- like stem cells that can migrate to damaged sites and contribute to tissue repair. Chronic cerebral hypoperfusion (CCH), which mimics vascular dementia, causes hippocampal neuronal degeneration and white matter (WM) damage, which lead to cognitive dysfunction. Currently, there are no effective treatments for it. We evaluated the efficiency of the human-Muse cell-based product CL2020 in treating CCH in rats. A bilateral common carotid artery occlusion was used to induce cognitive dysfunction. Six-weeks after carotid artery occlusion, CL2020 were injected intravenously. Cognitive function was assessed using a Barnes circular maze (BCM) at 3 weeks after CL2020 administration. Histological findings and western blots were assessed at 4 weeks after CL2020 administration. BCM assessment indicated recovery in cognitive function in the CL2020-treated group. Compared with the vehicle, CL2020 targeted the hippocampus, where it decreased neuronal loss and WM damage. CL2020 also promoted angiogenesis and suppressed apoptotic cell death. Western blotting of hippocampal samples revealed the downregulation of pro- apoptotic and the upregulation of anti-apoptotic proteins in the CL2020-treated group. In conclusion, intravenous administration of CL2020 improved the cognitive deficits caused by CCH, partly because of decreased hippocampal neuronal loss and WM damage, and increased angiogenesis in the hippocampus.

Adriamycin-induced nephropathy models: elucidating CKD pathophysiology and advancing therapeutic strategies

The Adriamycin-induced nephropathy (AN) model plays a crucial role in advancing our understanding of and research on chronic kidney disease (CKD). This review outlines methodologies for generating AN models in mice and rats, discusses their pathophysiologic and molecular characteristics, highlights their advantages and limitations, describes therapeutic interventions that have been evaluated in these models, and presents future research perspectives. The AN model replicates key features observed in human CKD, such as proteinuria, podocyte injury, glomerulosclerosis, and tubulointerstitial fibrosis. Notably, genetic factors significantly influence the onset and severity of AN, with mutations in the Prkdc gene linked to nephrotoxicity and systemic toxicity. To evaluate therapeutic interventions for CKD, agents such as ACE inhibitors, corticosteroids, and SGLT2 inhibitors have been tested in the AN model, demonstrating promising renoprotective effects. However, the systemic toxicity of Adriamycin and variability across models pose limitations, highlighting the need for caution when translating findings to human CKD. Future advancements in genetic engineering and the application of CRISPR-Cas9 technology are expected to improve the fidelity of AN models to human disease. Additionally, discovery of biomarkers by using the AN model enables us to improve early diagnosis. These efforts are anticipated to deepen our understanding of CKD pathophysiology and contribute to developing more effective diagnostic tools and targeted therapies.

Sphingosine-1-Phosphate Receptor 2 Agonist Mobilises Endogenous Muse Cells to Repair Damaged Myocardial Tissue in Male Rabbits

Muse cells, pluripotent stem cells present mainly in the bone marrow (BM) selectively accumulate to damaged tissue by sensing sphingosine-1-phosphate (S1P) and replace damaged cells by differentiating in situ. Acute myocardial infarction (AMI) model rabbits were subcutaneously injected either with Vehicle (n = 15), S1PR2-agonist (n = 16), or S1PR2-agonist + S1PR2-antagonist (n = 10). The number of Muse cells in the peripheral blood was assessed by flow cytometry at 12 h after AMI. The S1PR2-agonist group showed a significant increase in the peripheral-blood Muse cell number at 12 h (p < 0.05), as well as infarct size reduction (p < 0.05) and improvement of left ventricular (LV) function (p < 0.05) at 2 weeks compared with the other 2 groups. The number of peripheral-blood Muse cells positively correlated with LV ejection fraction (p < 0.05) and inversely correlated with infarct size (p < 0.05). Transplanted autologous green fluorescent protein (GFP)-labelled BM-Muse cells into the BM, followed by the administration of either Vehicle (n = 5) or S1PR2 agonist (n = 5) revealed a higher number of homed GFP-Muse cells expressing the cardiac markers troponin-I, α-actinin, connexin-43 and the vascular marker CD31 in the border areas in the S1PR2-agonist group compared with the vehicle group. The mobilisation of endogenous Muse cells using S1PR2-agonist may be a promising therapeutic approach.

Muse Cells Orchestrating Renal Repair via Macrophage M2 Polarization in Ischemia-Reperfusion Injury

Acute renal ischemia-reperfusion injury (IRI) poses significant challenges in clinical management, necessitating the exploration of novel therapeutic strategies. This study investigates the therapeutic potential and underlying mechanisms of multilineage-differentiating stress-enduring (Muse) cells in alleviating renal IRI. In recent years, stem cell research has advanced significantly, providing promising prospects for clinical treatment. Mesenchymal stromal cells (MSCs), from which Muse cells are derived, are a heterogeneous population of cells that include stem cells with varying degrees of multipotency, committed progenitors, and differentiated cells. Muse cells, a subpopulation of MSCs, were isolated from adipose tissue obtained through liposuction in this study. In vivo studies revealed the effective recruitment of Muse cells to injured kidneys and their ability to ameliorate renal pathological damage and improve renal function in a rat model of acute kidney IRI. Mechanistically, Muse cells modulated the polarization of macrophages toward an anti-inflammatory M2 phenotype, as evidenced by decreased M1/M2 ratios. In vitro experiments further elucidated the interaction between Muse cells and macrophages, demonstrating Muse cell-mediated promotion of M2 polarization. Co-culture with M2 macrophages during reoxygenation phases enhanced the survival of renal tubular epithelial cells following hypoxia-reoxygenation injury, highlighting the therapeutic potential of Muse cells in mitigating renal IRI through modulation of macrophage polarization. These findings provide insights into the therapeutic mechanisms of Muse cells and offer promising avenues for the development of innovative renal injury treatments.

Intravenous administration of muse cells improves cerebral ischemia outcome via immunomodulation in the spleen

Ischemic stroke is a leading cause of disability and death globally. Stem cell therapies are emerging as a frontier for enhancing post-stroke recovery, with Muse cells-a subclass of pluripotent stem cells-demonstrating considerable promise. Muse cells are notable not only for their potential in cell replacement but also for their role in modulating immune responses following cerebral infarction. In the present study, we administered Muse cells intravenously to mice after inducing a stroke via distal middle cerebral artery occlusion. We evaluated motor outcomes, splenocyte populations, cytokine profiles, and gene expression 2 weeks after inducing stroke. Additionally, comparisons were drawn between outcomes in splenectomized mice and those receiving adoptive splenocyte transfer to discern the specific influence of the spleen on treatment efficacy. Our findings revealed that Muse cell therapy facilitates motor recovery, an effect that is compromised in the absence of the spleen. Spleens in treated mice exhibited a shift in neutrophil counts, increased cytokine activity, and a notable uptick in the expression of genes related to protein folding. These insights affirm the potential therapeutic effect of Muse cells in post-stroke treatment strategies, with their efficacy attributed, at least in part, to immunomodulatory pathways involving the spleen.

Regulatory cell therapy for kidney transplantation and autoimmune kidney diseases

Regulatory cell therapies, including regulatory T cells and mesenchymal stromal cells, have shown promise in early clinical trials for reducing immunosuppression burden in transplantation. While regulatory cell therapies may also offer potential for treating autoimmune kidney diseases, data remains sparse, limited mainly to preclinical studies. This review synthesises current literature on the application of regulatory cell therapies in these fields, highlighting the safety and efficacy shown in existing clinical trials. We discuss the need for further clinical validation, optimisation of clinical and immune monitoring protocols, and the challenges of manufacturing and quality control under Good Manufacturing Practice conditions, particularly for investigator-led trials. Additionally, we explore the potential for expanding clinical indications and the unique challenges posed in paediatric applications. Future directions include scaling up production, refining protocols to ensure consistent quality across manufacturing sites, and extending applications to other immune-mediated diseases.

Accumulation of endogenous Muse cells in the myocardium and its pathophysiological role in patients with fulminant myocarditis

Multi-lineage differentiating stress-enduring (Muse) cells, identified as pluripotent surface marker SSEA-3(+) cells, are stress tolerant endogenous pluripotent-like stem cells, and are involved in tissue repair. However, the significance of Muse cells in acute myocarditis has not been evaluated. In the present study, we counted Muse cells/area in biopsied myocardial tissue samples from 17 patients with fulminant myocarditis, and 6 with non-inflammatory myocardial disease as controls. Compared with controls, patients with fulminant myocarditis had significantly more Muse cells (p = 0.00042). Patients with mechanical circulatory support (p = 0.006) and myocardial degeneration (p = 0.023) had significantly more Muse cells than those without them. The Muse cell number was correlated with acute phase CK-MB level (ρ = 0.547, p = 0.029), indicating the severity of myocardial injury, and was also correlated with acute/recovery phase ratio of CK-MB (ρ = 0.585, p = 0.023) and cardiac troponin I (ρ = 0.498, p = 0.047) levels, indicating resilience of myocardial injury. In fulminant myocarditis, the Muse cell number was associated with the severity of clinical features in the acute phase, and also with the recovery from myocardial damage in the chronic phase. Endogenous Muse cells might be mobilized and accumulate to the myocardial tissues in fulminant myocarditis, and might participate in the repair of injured myocardium.

Structural reconstruction of mouse acute aortic dissection by intravenously administered human Muse cells without immunosuppression

BACKGROUND

Stanford type B-acute aortic dissection (type B-AAD) is often life-threatening without invasive surgery. Multilineage-differentiating stress enduring cell (Muse cells), which comprise several percent of mesenchymal stem cells (MSCs), are endogenous pluripotent-like stem cells that selectively home to damaged tissue and replace damaged/apoptotic cells by in-vivo differentiation.

METHODS

Mortality, aortic diameter expansion, cell localization, cell differentiation, and inflammation of the dissected aorta were evaluated in type B-AAD model mice intravenously injected with human-Muse cells, -elastin-knockdown (KD)-Muse cells, -human leukocyte antigen-G (HLA-G)-KD-Muse cells, or MSCs, all without immunosuppressant.

RESULTS

Here, we show the Muse (50,000 cells) group has a lower incidence of aortic rupture and mortality of AAD compared with the MSC-50K (50,000 human-MSCs) and vehicle groups. Spectrum computed tomography in-vivo dynamics and 3-dimensional histologic analyses demonstrate that Muse cells more effectively home to the AAD tissue and survive for 8 weeks in the Muse group than in the MSC-750K (750,000 human-MSCs containing 50,000 Muse cells) group. Homing of Muse cells is impeded in the HLA-G-KD-Muse (50,000 cells) group. Differentiation of homed Muse cells into CD31(+) and alpha-smooth muscle actin (+) cells, production and reorganization of elastic fibers in the AAD tissue, and suppression of diameter expansion are greater in the Muse group than in the MSC-750K and elastin-KD-Muse (50,000 cells) groups.

CONCLUSIONS

Intravenously administered Muse cells reconstruct the dissected aorta and improve mortality and diameter enlargement rates. Moreover, small doses of purified Muse cells are more effective than large doses of MSCs. HLA-G is suggested to contribute to the successful survival and homing of Muse cells.

Human post-implantation blastocyst-like characteristics of Muse cells isolated from human umbilical cord

Muse cells, identified as cells positive for the pluripotent surface marker SSEA-3, are pluripotent-like endogenous stem cells located in the bone marrow (BM), peripheral blood, and organ connective tissues. The detailed characteristics of SSEA-3(+) cells in extraembryonic tissue, however, are unknown. Here, we demonstrated that similar to human-adult tissue-Muse cells collected from the BM, adipose tissue, and dermis as SSEA-3(+), human-umbilical cord (UC)-SSEA-3(+) cells express pluripotency markers, differentiate into triploblastic-lineage cells at a single cell level, migrate to damaged tissue, and exhibit low telomerase activity and non-tumorigenicity. Notably, ~ 20% of human-UC-SSEA-3(+) cells were negative for X-inactive specific transcript (XIST), a naïve pluripotent stem cell characteristic, whereas all human adult tissue-Muse cells are XIST-positive. Single-cell RNA sequencing revealed that the gene expression profile of human-UC-SSEA-3(+) cells was more similar to that of human post-implantation blastocysts than human-adult tissue-Muse cells. The DNA methylation level showed the same trend, and notably, the methylation levels in genes particularly related to differentiation were lower in human-UC-SSEA-3(+) cells than in human-adult tissue-Muse cells. Furthermore, human-UC-SSEA-3(+) cells newly express markers specific to extraembryonic-, germline-, and hematopoietic-lineages after differentiation induction in vitro whereas human-adult tissue-Muse cells respond only partially to the induction. Among various stem/progenitor cells in living bodies, those that exhibit properties similar to post-implantation blastocysts in a naïve state have not yet been found in humans. Easily accessible human-UC-SSEA-3(+) cells may be a valuable tool for studying early-stage human development and human reproductive medicine.

Multilineage-differentiating stress-enduring cells: a powerful tool for tissue damage repair

Multilineage-differentiating stress-enduring (Muse) cells are a type of pluripotent cell with unique characteristics such as non-tumorigenic and pluripotent differentiation ability. After homing, Muse cells spontaneously differentiate into tissue component cells and supplement damaged/lost cells to participate in tissue repair. Importantly, Muse cells can survive in injured tissue for an extended period, stabilizing and promoting tissue repair. In addition, it has been confirmed that injection of exogenous Muse cells exerts anti-inflammatory, anti-apoptosis, anti-fibrosis, immunomodulatory, and paracrine protective effects in vivo. The discovery of Muse cells is an important breakthrough in the field of regenerative medicine. The article provides a comprehensive review of the characteristics, sources, and potential mechanisms of Muse cells for tissue repair and regeneration. This review serves as a foundation for the further utilization of Muse cells as a key clinical tool in regenerative medicine.

Human Muse cells isolated from preterm- and term-umbilical cord delivered therapeutic effects in rat bleomycin-induced lung injury model without immunosuppressant

BACKGROUND

Bleomycin (BLM)-induced lung injury is characterized by mixed histopathologic changes with inflammation and fibrosis, such as observed in human patients with bronchopulmonary dysplasia, idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease. Although no curative therapies for these lung diseases exist, stem cell therapy has emerged as a potential therapeutic option. Multilineage-differentiating stress-enduring (Muse) cells are endogenous pluripotent- and macrophage-like stem cells distributed in various adult and fetal tissues as stage-specific embryonic antigen-3-positive cells. They selectively home to damaged tissue by sensing sphingosine-1-phosphate and replace the damaged/apoptotic cells by in vivo differentiation. Clinical trials for some human diseases suggest the safety and therapeutic efficacy of intravenously injected human leukocyte antigen-mismatched allogenic Muse cells from adult bone marrow (BM) without immunosuppressant. Here, we evaluated the therapeutic effects of human Muse cells from preterm and term umbilical cord (UC), and adult BM in a rat BLM-induced lung injury model.

METHODS

Rats were endotracheally administered BLM to induce lung injury on day 0. On day 3, human preterm UC-Muse, term UC-Muse, or adult BM-Muse cells were administered intravenously without immunosuppressants, and rats were subjected to histopathologic analysis on day 21. Body weight, serum surfactant protein D (SP-D) levels, and oxygen saturation (SpO2) were monitored. Histopathologic lung injury scoring by the Ashcroft and modified American Thoracic Society document scales, quantitative characterization of engrafted Muse cells, RNA sequencing analysis, and in vitro migration assay of infused Muse cells were performed.

RESULTS

Rats administered preterm- and term-UC-Muse cells exhibited a significantly better recovery based on weight loss, serum SP-D levels, SpO2, and histopathologic lung injury scores, and a significantly higher rate of both Muse cell homing to the lung and alveolar marker expression (podoplanin and prosurfactant protein-C) than rats administered BM-Muse cells. Rats receiving preterm-UC-Muse cells showed statistically superior results to those receiving term-UC-Muse cells in many of the measures. These findings are thought to be due to higher expression of genes related to cell migration, lung differentiation, and cell adhesion.

CONCLUSION

Preterm UC-Muse cells deliver more efficient therapeutic effects than term UC- and BM-Muse cells for treating BLM-induced lung injury in a rat model.

Intravenously engrafted human multilineage-differentiating stress-enduring (Muse) cells rescue erectile function after rat cavernous nerve injury

OBJECTIVE

To evaluate the effect of intravenous administration of human multilineage-differentiating stress-enduring (Muse) cells on rat postoperative erectile dysfunction (ED) with cavernous nerve (CN) injury without an immunosuppressant.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomised into three groups after CN crush injury. Either human-Muse cells, non-Muse mesenchymal stem cells (MSCs) (both 1.0 × 105 cells), or vehicle was infused intravenously at 3 h after CN injury without immunosuppressant. Erectile function was assessed by measuring intracavernous pressure (ICP) and arterial pressure (AP) during pelvic nerve electrostimulation 28 days after surgery. At 48 h and 28 days after intravenous infusion of Muse cells, the homing of Muse cells and non-Muse MSCs was evaluated in the major pelvic ganglion (MPG) after CN injury. In addition, expressions of C-X-C motif chemokine ligand (Cxcl12) and glial cell line-derived neurotrophic factor (Gdnf) in the MPG were examined by real-time polymerase chain reaction. Statistical analyses and comparisons among groups were performed using one-way analysis of variance followed by the Tukey test for parametric data and Kruskal-Wallis test followed by the Dunn-Bonferroni test for non-parametric data.

RESULTS

The mean (SEM) ICP/AP values at 28 days were 0.51 (0.02) in the Muse cell group, 0.37 (0.03) in the non-Muse MSC group, and 0.36 (0.04) in the vehicle group, showing a significant positive response in the Muse cell group compared with the non-Muse and vehicle groups (P = 0.013 and P = 0.010, respectively). In the MPG, Muse cells were observed to be engrafted at 48 h and expressed Schwann cell markers S100 (~46%) and glial fibrillary acidic protein (~24%) at 28 days, while non-Muse MSCs were basically not engrafted at 48 h. Higher gene expression of Cxcl12 (P = 0.048) and Gdnf (P = 0.040) was found in the MPG of the Muse group than in the vehicle group 48 h after infusion.

CONCLUSION

Intravenously engrafted human Muse cells recovered rat erectile function after CN injury in a rat model possibly by upregulating Cxcl12 and Gdnf.

Tumor suppressor let-7 acts as a key regulator for pluripotency gene expression in Muse cells

In embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), the expression of an RNA-binding pluripotency-relevant protein, LIN28, and the absence of its antagonist, the tumor-suppressor microRNA (miRNA) let-7, play a key role in maintaining pluripotency. Muse cells are non-tumorigenic pluripotent-like stem cells residing in the bone marrow, peripheral blood, and organ connective tissues as pluripotent surface marker SSEA-3(+). They express pluripotency genes, differentiate into triploblastic-lineage cells, and self-renew at the single cell level. Muse cells do not express LIN28 but do express let-7 at higher levels than in iPSCs. In Muse cells, we demonstrated that let-7 inhibited the PI3K-AKT pathway, leading to sustainable expression of the key pluripotency regulator KLF4 as well as its downstream genes, POU5F1, SOX2, and NANOG. Let-7 also suppressed proliferation and glycolysis by inhibiting the PI3K-AKT pathway, suggesting its involvement in non-tumorigenicity. Furthermore, the MEK/ERK pathway is not controlled by let-7 and may have a pivotal role in maintaining self-renewal and suppression of senescence. The system found in Muse cells, in which the tumor suppressor let-7, but not LIN28, tunes the expression of pluripotency genes, might be a rational cell system conferring both pluripotency-like properties and a low risk for tumorigenicity.

Intravenous Administration of Human Muse Cells Ameliorates Deficits in a Rat Model of Subacute Spinal Cord Injury

Multilineage-differentiating stress-enduring (Muse) cells are newly established pluripotent stem cells. The aim of the present study was to examine the potential of the systemic administration of Muse cells as an effective treatment for subacute SCI. We intravenously administered the clinical product "CL2020" containing Muse cells to a rat model two weeks after mid-thoracic spinal cord contusion. Eight experimental animals received CL2020, and twelve received the vehicle. Behavioral analyses were conducted over 20 weeks. Histological evaluations were performed. After 20 weeks of observation, diphtheria toxin was administered to three CL2020-treated animals to selectively ablate human cell functions. Hindlimb motor functions significantly improved from 6 to 20 weeks after the administration of CL2020. The cystic cavity was smaller in the CL2020 group. Furthermore, larger numbers of descending 5-HT fibers were preserved in the distal spinal cord. Muse cells in CL2020 were considered to have differentiated into neuronal and neural cells in the injured spinal cord. Neuronal and neural cells were identified in the gray and white matter, respectively. Importantly, these effects were reversed by the selective ablation of human cells by diphtheria toxin. Intravenously administered Muse cells facilitated the therapeutic potential of CL2020 for severe subacute spinal cord injury.

Systemic administration of clinical-grade multilineage-differentiating stress-enduring cells ameliorates hypoxic-ischemic brain injury in neonatal rats

Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative pluripotent stem cells present in the bone marrow, peripheral blood, and organ connective tissues. We assessed the homing and therapeutic effects of systemically administered nafimestrocel, a clinical-grade human Muse cell-based product, without immunosuppressants in a neonatal hypoxic-ischemic (HI) rat model. HI injury was induced on postnatal day 7 (P7) and was confirmed by T2-weighted magnetic resonance imaging on P10. HI rats received a single dose nafimestrocel (1 × 106 cells/body) or Hank's balanced salt solution (vehicle group) intravenously at either three days (on P10; M3 group) or seven days (on P14; M7 group) after HI insult. Radioisotope experiment demonstrated the homing of chromium-51-labeled nafimestrocel to the both cerebral hemispheres. The cylinder test (M3 and M7 groups) and open-field test (M7 group) showed significant amelioration of paralysis and hyperactivity at five weeks of age compared with those in the vehicle group. Nafimestrocel did not cause adverse events such as death or pathological changes in the lung at ten weeks in the both groups. Nafimestrocel attenuated the production of tumor necrosis factor-α and inducible nitric oxide synthase from activated cultured microglia in vitro. These results demonstrate the potential therapeutic benefits and safety of nafimestrocel.

Mesenchymal stem cells enhance CCL8 expression by podocytes in lupus-prone MRL.Faslpr mice

Nephritis is common in systemic lupus erythematosus patients and is associated with hyper-activation of immune and renal cells. Although mesenchymal stem cells (MSCs) ameliorate nephritis by inhibiting T and B cells, whether MSCs directly affect renal cells is unclear. To address this issue, we examined the direct effect of MSCs on renal cells with a focus on chemokines. We found that expression of CCL2, CCL3, CCL4, CCL5, CCL8, CCL19, and CXCL10 increased 1.6-5.6-fold in the kidney of lupus-prone MRL.Faslpr mice with advancing age from 9 to 16 weeks. Although MSCs inhibited the increase in the expression of most chemokines by 52-95%, they further increased CCL8 expression by 290%. Using renal cells, we next investigated how MSCs enhanced CCL8 expression. CCL8 was expressed by podocytes, but not by tubular cells. MSCs enhanced CCL8 expression by podocytes in a contact-dependent manner, which was proved by transwell assay and blocking with anti-VCAM-1 antibody. Finally, we showed that CCL8 itself activated MSCs to produce more immunosuppressive factors (IL-10, IDO, TGF-β1, and iNOS) and to inhibit more strongly IFN-γ production by T cells. Taken together, our data demonstrate that MSCs activate podocytes to produce CCL8 in a contact-dependent manner and conversely, podocyte-derived CCL8 might potentiate immunosuppressive activity of MSCs in a paracrine fashion. Our study documents a previously unrecognized therapeutic mechanism of MSCs in nephritis.

Multilineage Differentiating Stress Enduring (Muse) Cells: A New Era of Stem Cell-Based Therapy

Stem cell transplantation has recently demonstrated a significant therapeutic efficacy in various diseases. Multilineage-differentiating stress-enduring (Muse) cells are stress-tolerant endogenous pluripotent stem cells that were first reported in 2010. Muse cells can be found in the peripheral blood, bone marrow and connective tissue of nearly all body organs. Under basal conditions, they constantly move from the bone marrow to peripheral blood to supply various body organs. However, this rate greatly changes even within the same individual based on physical status and the presence of injury or illness. Muse cells can differentiate into all three-germ-layers, producing tissue-compatible cells with few errors, minimal immune rejection and without forming teratomas. They can also endure hostile environments, supporting their survival in damaged/injured tissues. Additionally, Muse cells express receptors for sphingosine-1-phosphate (S1P), which is a protein produced by damaged/injured tissues. Through the S1P-S1PR2 axis, circulating Muse cells can preferentially migrate to damaged sites following transplantation. In addition, Muse cells possess a unique immune privilege system, facilitating their use without the need for long-term immunosuppressant treatment or human leucocyte antigen matching. Moreover, they exhibit anti-inflammatory, anti-apoptotic and tissue-protective effects. These characteristics circumvent all challenges experienced with mesenchymal stem cells and induced pluripotent stem cells and encourage the wide application of Muse cells in clinical practice. Indeed, Muse cells have the potential to break through the limitations of current cell-based therapies, and many clinical trials have been conducted, applying intravenously administered Muse cells in stroke, myocardial infarction, neurological disorders and acute respiratory distress syndrome (ARDS) related to novel coronavirus (SARS-CoV-2) infection. Herein, we aim to highlight the unique biological properties of Muse cells and to elucidate the advantageous difference between Muse cells and other types of stem cells. Finally, we shed light on their current therapeutic applications and the major obstacles to their clinical implementation from laboratory to clinic.

Ephedra Herb extract ameliorates adriamycin-induced nephrotic syndrome in rats via the CAMKK2/AMPK/mTOR signaling pathway

This study aimed to investigate the effect and mechanisms of Ephedra Herb (EH) extract on adriamycin-induced nephrotic syndrome (NS), providing an experimental basis for the clinical treatment of NS. Hematoxylin and eosin staining, creatinine, urea nitrogen, and kidn injury molecule-1 were used to evaluate the activities of EH extract on renal function. The levels of inflammatory factors and oxidative stress were detected by kits. The levels of reactive oxygen species, immune cells, and apoptosis were measured by flow cytometry. A network pharmacological approach was used to predict the potential targets and mechanisms of EH extract in the treatment of NS. The protein levels of apoptosis-related proteins and CAMKK2, p-CAMKK2, AMPK, p-AMPK, mTOR and p-mTOR in the kidneys were detected by Western blot. The effective material basis of EH extract was screened by MTT assay. The AMPK pathway inhibitor (compound C, CC) was added to investigate the effect of the potent material basis on adriamycin-induced cell injury. EH extract significantly improved renal injury and relieve inflammation, oxidative stress, and apoptosis in rats. Network pharmacology and Western blot results showed that the effect of EH extract on NS may be associated with the CAMKK2/AMPK/mTOR signaling pathway. Moreover, methylephedrine significantly ameliorated adriamycin-induced NRK-52e cell injury. Methylephedrine also significantly improved the phosphorylation of AMPK and mTOR, which were blocked by CC. In sum, EH extract may ameliorate renal injury via the CAMKK2/AMPK/mTOR signaling pathway. Moreover, methylephedrine may be one of the material bases of EH extract.

Multilineage-Differentiating Stress-Enduring Cells (Muse Cells): The Future of Human and Veterinary Regenerative Medicine

In recent years, several studies have been conducted on Muse cells mainly due to their pluripotency, high tolerance to stress, self-renewal capacity, ability to repair DNA damage and not being tumoral. Additionally, since these stem cells can be isolated from different tissues in the adult organism, obtaining them is not considered an ethical problem, providing an advantage over embryonic stem cells. Regarding their therapeutic potential, few studies have reported clinical applications in the treatment of different diseases, such as aortic aneurysm and chondral injuries in the mouse or acute myocardial infarction in the swine, rabbit, sheep and in humans. This review aims to describe the characterization of Muse cells, show their biological characteristics, explain the differences between Muse cells and mesenchymal stem cells, and present their contribution to the treatment of some diseases.

Intravenous administration of human Muse cells recovers blood flow in a mouse model of hindlimb ischemia

Cell-based therapies hold great promise for the treatment of peripheral arterial disease (PAD), especially in patients presenting with severe limb ischemia, although the optimal strategy remains to be explored. In this study, we evaluated the therapeutic effect of intravenous administration of human Muse cells, a unique subpopulation of mesenchymal stem cells (MSC), using a mouse model of hindlimb ischemia (HLI) without an immunosuppressant. Compared with the phosphate buffered saline (PBS) or non-Muse MSC groups, the Muse group showed significantly higher laser doppler blood flow in the ischemic limb at days 7 and 14 after HLI. Increased microvascular density [percent area of CD31(+) cells] and reduced interstitial fibrosis in the ischemic limb muscle were also observed in the Muse group. mCherry-expressing Muse cells were found in the ischemic border zone and expressed CD31 but did not in the non-ischemic limb. Muse cells produced higher amounts of vascular endothelial growth factor (VEGF) than non-Muse cells under normoxic and hypoxic conditions in vitro. In the ischemic muscle, tissue VEGF concentration and angiogenesis-related genes such as Vegfa, Angpt1, Pdgfb, and Igf1 were significantly higher in the Muse group than in the other two groups. In addition, the proportion of M2 macrophages to total macrophages and the ratio of anti-inflammatory-related genes such as IL-10, Arg1, and CD206 per iNOS were significantly higher in the Muse group than in the other two groups. In summary, Muse cells exert pleiotropic effects in a mouse model of HLI, and therefore may provide a novel therapeutic approach for the treatment of PAD patients with severe limb ischemia.

Endogenous reparative pluripotent Muse cells with a unique immune privilege system: Hint at a new strategy for controlling acute and chronic inflammation

Multilineage-differentiating stress enduring (Muse) cells, non-tumorigenic endogenous pluripotent stem cells, reside in the bone marrow (BM), peripheral blood, and connective tissue as pluripotent surface marker SSEA-3(+) cells. They express other pluripotent markers, including Nanog, Oct3/4, and Sox2 at moderate levels, differentiate into triploblastic lineages, self-renew at a single cell level, and exhibit anti-inflammatory effects. Cultured mesenchymal stromal cells (MSCs) and fibroblasts contain several percent of SSEA-3(+)-Muse cells. Circulating Muse cells, either endogenous or administered exogenously, selectively accumulate at the damaged site by sensing sphingosine-1-phosphate (S1P), a key mediator of inflammation, produced by damaged cells and replace apoptotic and damaged cells by spontaneously differentiating into multiple cells types that comprise the tissue and repair the tissue. Thus, intravenous injection is the main route for Muse cell treatment, and surgical operation is not necessary. Furthermore, gene introduction or cytokine induction are not required for generating pluripotent or differentiated states prior to treatment. Notably, allogenic and xenogenic Muse cells escape host immune rejection after intravenous injection and survive in the tissue as functioning cells over 6 and ∼2 months, respectively, without immunosuppressant treatment. Since Muse cells survive in the host tissue for extended periods of time, therefore their anti-inflammatory, anti-fibrotic, and trophic effects are long-lasting. These unique characteristics have led to the administration of Muse cells via intravenous drip in clinical trials for stroke, acute myocardial infarction, epidermolysis bullosa, spinal cord injury, neonatal hypoxic ischemic encephalopathy, amyotrophic lateral sclerosis, and COVID-19 acute respiratory distress syndrome without HLA-matching or immunosuppressive treatment.

Inhibition of Gap Junctional Intercellular Communication Upregulates Pluripotency Gene Expression in Endogenous Pluripotent Muse Cells

Gap junctions (GJ) are suggested to support stem cell differentiation. The Muse cells that are applied in clinical trials are non-tumorigenic pluripotent-like endogenous stem cells, can be collected as stage-specific embryonic antigen 3 (SSEA-3+) positive cells from multiple tissues, and show triploblastic differentiation and self-renewability at a single cell level. They were reported to up-regulate pluripotency gene expression in suspension. We examined how GJ inhibition affected pluripotency gene expression in adherent cultured-Muse cells. Muse cells, mainly expressing gap junction alpha-1 protein (GJA1), reduced GJ intercellular communication from ~85% to 5-8% after 24 h incubation with 120 μM 18α-glycyrrhetinic acid, 400 nM 12-O-tetradecanoylphorbol-13-acetate, and 90 μM dichlorodiphenyltrichloroethane, as confirmed by a dye-transfer assay. Following inhibition, NANOG, OCT3/4, and SOX2 were up-regulated 2-4.5 times more; other pluripotency-related genes, such as KLF4, CBX7, and SPRY2 were elevated; lineage-specific differentiation-related genes were down-regulated in quantitative-PCR and RNA-sequencing. Connexin43-siRNA introduction also confirmed the up-regulation of NANOG, OCT3/4, and SOX2. YAP, a co-transcriptional factor in the Hippo signaling pathway that regulates pluripotency gene expression, co-localized with GJA1 (also known as Cx43) in the cell membrane and was translocated to the nucleus after GJ inhibition. Adherent culture is usually more suitable for the stable expansion of cells than is a suspension culture. GJ inhibition is suggested to be a simple method to up-regulate pluripotency in an adherent culture that involves a Cx43-YAP axis in pluripotent stem cells, such as Muse cells.

Muse cells: ushering in a new era of stem cell-based therapy for stroke

Stem cell-based regenerative therapies have recently become promising and advanced for treating stroke. Mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs) have received the most attention for treating stroke because of the outstanding paracrine function of MSCs and the three-germ-layer differentiation ability of iPSCs. However, the unsatisfactory homing ability, differentiation, integration, and survival time in vivo limit the effectiveness of MSCs in regenerative medicine. The inherent tumorigenic property of iPSCs renders complete differentiation necessary before transplantation, which is complicated and expensive and affects the consistency among cell batches. Multilineage differentiating stress-enduring (Muse) cells are natural pluripotent stem cells in the connective tissues of nearly every organ and thus are considered nontumorigenic. A single Muse cell can differentiate into all three-germ-layer, preferentially migrate to damaged sites after transplantation, survive in hostile environments, and spontaneously differentiate into tissue-compatible cells, all of which can compensate for the shortcomings of MSCs and iPSCs. This review summarizes the recent progress in understanding the biological properties of Muse cells and highlights the differences between Muse cells and other types of stem cells. Finally, we summarized the current research progress on the application of Muse cells on stroke and challenges from bench to bedside.

Mobilization of multilineage-differentiating stress-enduring cells into the peripheral blood in liver surgery

Purpose

This study investigated whether liver damage severity relates to the mobilization of multilineage-differentiating stress-enduring (Muse) cells, which are endogenous reparative pluripotent stem cells, into the peripheral blood (PB) and whether the degree of mobilization relates to the recovery of liver volume following human liver surgery.

Methods

Forty-seven patients who underwent liver surgery were included in the present study. PB-Muse cells were counted before surgery, on postoperative days (PODs) 3 and on POD 7. Liver volume was measured using computed tomography before and after surgery.

Results

The PB-Muse cell count increased after surgery. The number of PB-Muse cells before surgery was higher, but without statistical significance in the group with neoplasms than in the healthy group that included liver donors (p = 0.065). Forty-seven patients who underwent liver surgery were divided into major hepatic resection (MHR; hepatectomy of three or more segments according to the Couinaud classification, n = 22) and minor hepatic resection (mhr; hepatectomy of two segments or less according to the Couinaud classification, n = 25) groups. PB-Muse cells increased at high rates among MHR patients (p = 0.033). Except for complication cases, PB-Muse cells increased at higher rates in the group with advanced liver volume recovery (p = 0.043). The predictive impact of the rate of increase in PB-Muse cells on the recovery of liver volume was demonstrated by multivariate analysis (OR 11.0, p = 0.014).

Conclusions

PB-Muse cell mobilization correlated with the volume of liver resection, suggesting that the PB-Muse cell number reflects the degree of liver injury. Given that the degree of PB-Muse cell mobilization was related to liver volume recovery, PB-Muse cells were suggested to contribute to liver regeneration, although this mechanism remains unclear.

Potential Strategies for Kidney Regeneration With Stem Cells: An Overview

Kidney diseases are a major health problem worldwide. Despite advances in drug therapies, they are only capable of slowing the progression of kidney diseases. Accordingly, potential kidney regeneration strategies with stem cells have begun to be explored. There are two different directions for regenerative strategies, de novo whole kidney fabrication with stem cells, and stem cell therapy. De novo whole kidney strategies include: 1) decellularized scaffold technology, 2) 3D bioprinting based on engineering technology, 3) kidney organoid fabrication, 4) blastocyst complementation with chimeric technology, and 5) the organogenic niche method. Meanwhile, stem cell therapy strategies include 1) injection of stem cells, including mesenchymal stem cells, nephron progenitor cells, adult kidney stem cells and multi-lineage differentiating stress enduring cells, and 2) injection of protective factors secreted from these stem cells, including growth factors, chemokines, and extracellular vesicles containing microRNAs, mRNAs and proteins. Over the past few decades, there have been remarkable step-by-step developments in these strategies. Here, we review the current advances in the potential strategies for kidney regeneration using stem cells, along with their challenges for possible clinical use in the future.

Intravenous injection of human multilineage-differentiating stress-enduring cells alleviates mouse severe acute pancreatitis without immunosuppressants

INTRODUCTION

We examined the effect of intravenously injected human multilineage-differentiating stress-enduring (Muse) cells, non-tumorigenic endogenous reparative stem cells already used in clinical trials, on a severe acute pancreatitis (SAP) mouse model without immunosuppressants.

METHODS

Human Muse cells (1.0 × 105 cells) collected from mesenchymal stem cells (MSCs) as SSEA-3(+) were injected into a C57BL/6 mouse model via the jugular vein 6 h after SAP-induction with taurocholate. The control group received saline or the same number of SSEA-3(-)-non-Muse MSCs.

RESULTS

Edematous parameters, F4/80(+) macrophage infiltration and terminal deoxynucleotidyl transferase dUTP nick-end labeling positivity was the lowest and the number of proliferating endogenous pancreatic progenitors (CK18(+)/Ki67(+) cells) the highest in the Muse group among the three groups, with statistical significance, at 72 h. An enzyme-linked immunosorbent assay and quantitative polymerase chain reaction demonstrated that in vitro production of VEGF, HGF, IGF-1, and MMP-2, which are relevant to tissue protection, anti-inflammation, and anti-fibrosis, were higher in Muse cells than in non-Muse MSCs, particularly when cells were cultured in SAP mouse serum. Consistently, the pancreas of animals in the Muse group contained higher amounts of those factors according to Western blotting at 18 h than that in the non-Muse MSCs and control groups.

CONCLUSIONS

Intravenous injection of human Muse cells was suggested to be effective for attenuating edema, inflammation and apoptosis in the acute phase of SAP.

Effects of human Muse cells on bladder inflammation, overactivity, and nociception in a chemically induced Hunner-type interstitial cystitis-like rat model

INTRODUCTION AND HYPOTHESIS

We investigated the effects of locally administered human multilineage-differentiating stress enduring (Muse) cells, nontumorigenic pluripotent-like endogenous stem cells, on bladder tissues, function, and nociceptive behavior in a chemically induced Hunner-type interstitial cystitis (HIC)-like rat model without immunosuppressant.

METHODS

Chemical cystitis was induced by intravesical instillation of 0.2 N hydrochloride (HCl) for 15 min in female F344 rats. SSEA-3⁺ Muse cells, SSEA-3^- non-Muse cells or Hanks' balanced salt solution (HBSS; vehicle) were injected into the anterior and posterior bladder wall at each 1×10⁴ cells/10 μl 6 h after HCl application. The sham group received HBSS without HCl instillation. Urinary frequency was assessed using metabolic cages, cystometrograms, nociceptive behavior, and histological analysis of the bladder and L6 spinal cord.

RESULTS

Increases in urinary frequency and decreases in bladder capacity compared with the sham group were observed in the vehicle and non-Muse groups, but not in the Muse group, at 1 week. Significant increases in nociceptive behavior compared with the sham group and the expression of TNFα in the bladder and c-Fos in the bilateral dorsal horns of L6 spinal cord were also observed in the vehicle and non-Muse groups, whereas these changes were not seen in the Muse group at 1 week. Histological analysis exhibited a higher proportion of injected Muse cells remaining in the urothelial basal layer and lamina propria of the bladder than non-Muse cells until 4 weeks.

CONCLUSIONS

Muse cell therapy could be a promising modality for treating HIC.

Multilineage-differentiating stress-enduring cells alleviate atopic dermatitis-associated behaviors in mice

BACKGROUND

Pruritus is a recurring, long-lasting skin disease with few effective treatments. Many patients have unsatisfactory responses to currently available antipruritic treatments, and effective therapeutics are urgently needed to relieve symptoms. A previous study reported that mesenchymal stem cell (MSC)-mediated immune regulation could be used to treat skin inflammatory diseases. Multilineage-differentiating stress-enduring (Muse) cells are a new type of pluripotent stem cell that may also have the potential to treat inflammatory skin diseases.

METHODS

Muse cells were isolated from human bone marrow-derived MSCs (BMSCs) via the 8-h longterm trypsin incubation (LTT) method. Repeated use of 2,4-dinitrofluorobenzene (DNFB) induced atopic dermatitis (AD) in a mouse model. Immunofluorescence, behavior recording, and image analysis were used to evaluate the therapeutic effect of subcutaneous Muse cell injection. Real-time quantitative polymerase chain reaction (qPCR) was used to measure the expression of inflammatory factors. In vitro, wound healing and cell proliferation experiments were used to examine the effect of Muse cell supernatant on keratinocytes.

RESULTS

Our results showed that subcutaneous injection of Muse cells after AD model induction significantly alleviated scratching behavior in mice. The evaluation of dermatitis and photos of damaged skin on the back of the neck revealed that Muse cells reduced dermatitis, playing an active role in healing the damaged skin. The activation of spinal glial cells and scratching behavior were also reduced by Muse cell injection. In addition, we also showed that the expression levels of the inflammatory factors interleukin (IL)-6, IL-17α, and IL-33 in both the spinal cord and skin were suppressed by Muse cells. Furthermore, Muse cells not only exerted anti-inflammatory effects on lipopolysaccharide (LPS)-induced human HaCat cells but also promoted wound healing and keratinocyte proliferation.

CONCLUSIONS

In vivo, Muse cells could alleviate scratching symptoms, reduce epidermal inflammation, and promote wound healing. In vitro, Muse cells could also promote the migration and proliferation of keratinocytes. In summary, Muse cells may become a new therapeutic agent for the treatment of AD.

The protective impact of berberine against doxorubicin-induced nephrotoxicity in rats

Doxorubicin (DOX) is a well-known anti-neoplastic agent that is widely employed to treat several types of malignancies. The current study was designed to investigate the renoprotective potential of berberine (BEB) on the doxorubicin (DOX)-induced nephrotoxicity and renal fibrosis. Rats were allocated into four groups; Negative Control, DOX nephrotoxic-induced group received a single dose of DOX (20 mg/kg, i.p.), BEB-group received (50 mg/kg, p.o.) for 14 days, and co-treatment group BEB + DOX where rats were pre-treated with BEB for 10 successive days, then received a single dose of DOX on the 11th day, followed by 4 days of receiving BEB. DOX resulted in nephrotoxicity manifested by significant increments in urea, creatinine, and kidney injury molecule (KIM-1), these biochemical findings were supported with the histopathological lesions in renal tissues. Moreover, DOX provoked oxidative stress through enhancing renal malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents, and decreased renal catalase (CAT) activity. DOX triggered renal fibrosis represented by increased transforming growth factor beta-1 (TGF-β1) and elevated collagen deposition. DOX stimulated apoptosis and inflammation in renal tissues as confirmed by increased immunoexpression of caspase-3 and NF-κB, respectively. These effects were alleviated by BEB co-treatment. Co-treatment with BEB markedly prohibited DOX-induced oxidative damage, inflammation, apoptosis, and fibrosis in renal tissue. Histopathological and immunohistochemical investigations showed the nephroprotective potential of BEB on renal injury, which was consistent with the biochemical findings. Accordingly, it could be concluded that the nephroprotective potential of BEB against DOX-induced kidney injury and fibrosis might be mediated by the anti-oxidant, anti-inflammatory and anti-fibrosis activities.

Human dental pulp stem cells attenuate streptozotocin-induced parotid gland injury in rats

OBJECTIVE

Diabetes mellitus causes deterioration in the body, including serious damage of the oral cavity related to salivary gland dysfunction, characterised by hyposalivation and xerostomia. Human dental pulp stem cells (hDPSCs) represent a promising therapy source, due to the easy, minimally invasive surgical access to these cells and their high proliferative capacity. It was previously reported that the trophic support mediated by these cells can rescue the functional and structural alterations of damaged salivary glands. However, potential differentiation and paracrine effects of hDPSCs in diabetic-induced parotid gland damage have not been investigated. Our study aimed to investigate the therapeutic effects of intravenous transplantation of hDPSCs on parotid gland injury in a rat model of streptozotocin (STZ)-induced type 1 diabetes.

METHODS

Thirty Sprague-Dawley male rats were randomly categorised into three groups: control, diabetic (STZ), and transplanted (STZ + hDPSCs). The hDPSCs or the vehicles were injected into the rats' tail veins, 7 days after STZ injection. Fasting blood glucose levels were monitored weekly. A glucose tolerance test was performed, and the parotid gland weight, salivary flow rate, oxidative stress indices, parotid gland histology, and caspase-3, vascular endothelial growth factor, proliferating cell nuclear antigen, neuronal nitric oxide synthase, endothelial nitric oxide synthase, and tetrahydrobiopterin biosynthetic enzyme expression levels in parotid tissues were assessed 28 days post-transplantation.

RESULTS

Transplantation of hDPSCs decreased blood glucose, improved parotid gland weight and salivary flow rate, and reduced oxidative stress. The cells migrated to the STZ-injured parotid gland and differentiated into acinar, ductal, and myoepithelial cells. Moreover, hDPSCs downregulated the expression of caspase-3 and upregulated the expression of vascular endothelial growth factor and proliferating cell nuclear antigen, likely exerting pro-angiogenic and anti-apoptotic effects and promoting endogenous regeneration. In addition, the transplanted cells enhanced the parotid nitric oxide-tetrahydrobiopterin pathway.

CONCLUSIONS

Our results showed that hDPSCs migrated to and survived within the STZ-injured parotid gland, where functional and morphological damage was prevented due to the restoration of normal glucose levels, differentiation into parotid cell populations, and stimulation of paracrine-mediated regeneration. Thus, hDPSCs may have potential in the treatment of diabetes-induced parotid gland injury.

Intravenously delivered multilineage-differentiating stress enduring cells dampen excessive glutamate metabolism and microglial activation in experimental perinatal hypoxic ischemic encephalopathy

Perinatal hypoxic ischemic encephalopathy (HIE) results in serious neurological dysfunction and mortality. Clinical trials of multilineage-differentiating stress enduring cells (Muse cells) have commenced in stroke using intravenous delivery of donor-derived Muse cells. Here, we investigated the therapeutic effects of human Muse cells in an HIE model. Seven-day-old rats underwent ligation of the left carotid artery then were exposed to 8% oxygen for 60 min, and 72 hours later intravenously transplanted with 1 × 10⁴ of human-Muse and -non-Muse cells, collected from bone marrow-mesenchymal stem cells as stage-specific embryonic antigen-3 (SSEA-3)+ and -, respectively, or saline (vehicle) without immunosuppression. Human-specific probe revealed Muse cells distributed mainly to the injured brain at 2 and 4 weeks, and expressed neuronal and glial markers until 6 months. In contrast, non-Muse cells lodged in the lung at 2 weeks, but undetectable by 4 weeks. Magnetic resonance spectroscopy and positron emission tomography demonstrated that Muse cells dampened excitotoxic brain glutamatergic metabolites and suppressed microglial activation. Muse cell-treated group exhibited significant improvements in motor and cognitive functions at 4 weeks and 5 months. Intravenously transplanted Muse cells afforded functional benefits in experimental HIE possibly via regulation of glutamate metabolism and reduction of microglial activation.

Protection of liver sinusoids by intravenous administration of human Muse cells in a rat extra-small partial liver transplantation model

Small-for-size syndrome (SFSS) has a poor prognosis due to excessive shear stress and sinusoidal microcirculatory disturbances in the acute phase after living-donor liver transplantation (LDLT). Multilineage-differentiating stress enduring (Muse) cells are reparative stem cells found in various tissues and currently under clinical trials. These cells selectively home to damaged sites via the sphingosine-1-phosphate (S1P)-S1P receptor 2 system and repair damaged tissue by pleiotropic effects, including tissue protection and damaged/apoptotic cell replacement by differentiating into tissue-constituent cells. The effects of intravenously administered human bone marrow-Muse cells and -mesenchymal stem cells (MSCs) (4 × 105 ) on liver sinusoidal endothelial cells (LSECs) were examined in a rat SFSS model without immunosuppression. Compared with MSCs, Muse cells intensively homed to the grafted liver, distributed to the sinusoids and vessels, and delivered improved blood chemistry and Ki-67(+) proliferative hepatocytes and -LSECs within 3 days. Tissue clearing and three-dimensional imaging by multiphoton laser confocal microscopy revealed maintenance of the sinusoid continuity, organization, and surface area, as well as decreased sinusoid interruption in the Muse group. Small-interfering RNA-induced knockdown of hepatocyte growth factor and vascular endothelial growth factor-A impaired the protective effect of Muse cells on LSECs. Intravenous injection of Muse cells might be a feasible approach for LDLT with less recipient burden.

Diverse cellular origins of adult blood vascular endothelial cells

During embryonic stages, vascular endothelial cells (ECs) originate from the mesoderm, at specific extraembryonic and embryonic regions, through a process called vasculogenesis. In the adult, EC renewal/replacement mostly depend on local resident ECs or endothelial progenitor cells (EPCs). Nevertheless, contribution from circulating ECs/EPCs was also reported. In addition, cells lacking from EC/EPC markers with in vitro extended plasticity were shown to originate endothelial-like cells (ELCs). Most of these cells consist of mesenchymal stromal progenitors, which would eventually get mobilized from the bone marrow after injury. Based on that, current knowledge on different mouse and human bone marrow stromal cell (BM-SC) subpopulations, able to contribute with mesenchymal stromal/stem cells (MSCs), is herein reviewed. Such analyses underline an unexpected heterogeneity among sinusoidal LepR⁺ stromal/CAR cells. For instance, in a recent report a subgroup of LepR⁺ stromal/CAR progenitors, which express GLAST and is traced in Wnt1^Cre;R26R^Tom mice, was found to contribute with ELCs in vivo. These GLAST ​⁺ ​Wnt1⁺ BM-SCs were shown to get mobilized to the peripheral blood and to contribute with liver regeneration. Other sources of ELCs, such as adipose, neural and dental pulp tissues, were also published. Finally, mechanisms likely involved in the enhanced cellular plasticity properties of bone marrow/adipose tissue stromal cells, able to originate ELCs, are assessed. In the future, strategies to analyze the in vivo expression profile of stromal cells, with MSC properties, in combination with screening of active genomic regions at the single cell-level, during early postnatal development and/or after injury, will likely help understanding properties of these ELC sources.

Injection of hybrid 3D spheroids composed of podocytes, mesenchymal stem cells, and vascular endothelial cells into the renal cortex improves kidney function and replenishes glomerular podocytes

Podocytes are highly differentiated epithelial cells that are crucial for maintaining the glomerular filtration barrier in the kidney. Podocyte injury followed by depletion is the major cause of pathological progression of kidney diseases. Although cell therapy has been considered a promising alternative approach to kidney transplantation for the treatment of kidney injury, the resultant therapeutic efficacy in terms of improved renal function is limited, possibly owing to significant loss of engrafted cells. Herein, hybrid three-dimensional (3D) cell spheroids composed of podocytes, mesenchymal stem cells, and vascular endothelial cells were designed to mimic the glomerular microenvironment and as a cell delivery vehicle to replenish the podocyte population by cell transplantation. After creating a native glomerulus-like condition, the expression of multiple genes encoding growth factors and basement membrane factors that are strongly associated with podocyte maturation and functionality was significantly enhanced. Our in vivo results demonstrated that intrarenal transplantation of podocytes in the form of hybrid 3D cell spheroids improved engraftment efficiency and replenished glomerular podocytes. Moreover, the proteinuria of the experimental mice with hypertensive nephropathy was effectively reduced. These data clearly demonstrated the potential of hybrid 3D cell spheroids for repairing injured kidneys.

Non-Tumorigenic Pluripotent Reparative Muse Cells Provide a New Therapeutic Approach for Neurologic Diseases

Muse cells are non-tumorigenic endogenous reparative pluripotent cells with high therapeutic potential. They are identified as cells positive for the pluripotent surface marker SSEA-3 in the bone marrow, peripheral blood, and connective tissue. Muse cells also express other pluripotent stem cell markers, are able to differentiate into cells representative of all three germ layers, self-renew from a single cell, and are stress tolerant. They express receptors for sphingosine-1-phosphate (S1P), which is actively produced by damaged cells, allowing circulating cells to selectively home to damaged tissue. Muse cells spontaneously differentiate on-site into multiple tissue-constituent cells with few errors and replace damaged/apoptotic cells with functional cells, thereby contributing to tissue repair. Intravenous injection of exogenous Muse cells to increase the number of circulating Muse cells enhances their reparative activity. Muse cells also have a specific immunomodulatory system, represented by HLA-G expression, allowing them to be directly administered without HLA-matching or immunosuppressant treatment. Owing to these unique characteristics, clinical trials using intravenously administered donor-Muse cells have been conducted for myocardial infarction, stroke, epidermolysis bullosa, spinal cord injury, perinatal hypoxic ischemic encephalopathy, and amyotrophic lateral sclerosis. Muse cells have the potential to break through the limitations of current cell therapies for neurologic diseases, including amyotrophic lateral sclerosis. Muse cells provide a new therapeutic strategy that requires no HLA-matching or immunosuppressant treatment for administering donor-derived cells, no gene introduction or differentiation induction for cell preparation, and no surgery for delivering the cells to patients.

Potential Mechanisms and Perspectives in Ischemic Stroke Treatment Using Stem Cell Therapies

Ischemic stroke (IS) remains one of the major causes of death and disability due to the limited ability of central nervous system cells to regenerate and differentiate. Although several advances have been made in stroke therapies in the last decades, there are only a few approaches available to improve IS outcome. In the acute phase of IS, mechanical thrombectomy and the administration of tissue plasminogen activator have been widely used, while aspirin or clopidogrel represents the main therapy used in the subacute or chronic phase. However, in most cases, stroke patients fail to achieve satisfactory functional recovery under the treatments mentioned above. Recently, cell therapy, especially stem cell therapy, has been considered as a novel and potential therapeutic strategy to improve stroke outcome through mechanisms, including cell differentiation, cell replacement, immunomodulation, neural circuit reconstruction, and protective factor release. Different stem cell types, such as mesenchymal stem cells, marrow mononuclear cells, and neural stem cells, have also been considered for stroke therapy. In recent years, many clinical and preclinical studies on cell therapy have been carried out, and numerous results have shown that cell therapy has bright prospects in the treatment of stroke. However, some cell therapy issues are not yet fully understood, such as its optimal parameters including cell type choice, cell doses, and injection routes; therefore, a closer relationship between basic and clinical research is needed. In this review, the role of cell therapy in stroke treatment and its mechanisms was summarized, as well as the function of different stem cell types in stroke treatment and the clinical trials using stem cell therapy to cure stroke, to reveal future insights on stroke-related cell therapy, and to guide further studies.

The evaluation of the safety and efficacy of intravenously administered allogeneic multilineage-differentiating stress-enduring cells in a swine hepatectomy model

INTRODUCTION

Multilineage-differentiating stress-enduring (Muse) cells are non-tumorigenic endogenous pluripotent-like cells residing in the bone marrow that exert a tissue reparative effect by replacing damaged/apoptotic cells through spontaneous differentiation into tissue-constituent cells. Post-hepatectomy liver failure (PHLF) is a potentially fatal complication. The main purpose of this study was to evaluate the safety and efficiency of allogeneic Muse cell administration via the portal vein in a swine model of PHLF.

METHODS

Swine Muse cells, collected from swine bone marrow-mesenchymal stem cells (MSCs) as SSEA-3(+) cells, were examined for their characteristics. Then, 1 × 107 allogeneic-Muse cells and allogeneic-MSCs and vehicle were injected via the portal vein in a 70% hepatectomy swine model.

RESULTS

Swine Muse cells exhibited characteristics comparable to previously reported human Muse cells. Compared to the MSC and vehicle groups, the Muse group showed specific homing of the administered cells into the liver, resulting in improvements in the control of hyperbilirubinemia (P = 0.04), prothrombin international normalized ratio (P = 0.05), and suppression of focal necrosis (P = 0.04). Integrated Muse cells differentiated spontaneously into hepatocyte marker-positive cells.

CONCLUSIONS

Allogeneic Muse cell administration may provide a reparative effect and functional recovery in a 70% hepatectomy swine model and thus may contribute to the treatment of PHLF.

Long-Term Trypsin Treatment Promotes Stem Cell Potency of Canine Adipose-Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) isolated from adipose tissue (adipose-derived stem cells [ADSCs]) are considered one of the most promising cell types for applications in regenerative medicine. However, the regenerative potency of ADSCs may vary because of heterogeneity. Long-term trypsin treatment (LTT) is known to significantly concentrate multilineage-differentiating stress-enduring (Muse) cells from human MSCs. In this study, we aimed to generate cells with high stem cell potency from canine ADSCs using LTT. After 16 h of treatment with trypsin, surviving ADSCs (LTT-tolerant cells) had significantly enhanced expression of stage-specific embryonic antigen (SSEA)-1, a mouse embryonic stem cell marker, and fucosyltransferase 9, one of several fucosyltransferases for SSEA-1 biosynthesis. However, LTT-tolerant cells did not enhance the expression of SSEA-3, a known human Muse cell marker. LTT-tolerant cells, however, showed significantly higher self-renewal capacity in the colony-forming unit fibroblast assay than ADSCs. In addition, the LTT-tolerant cells formed cell clusters similar to embryoid bodies and expressed undifferentiated markers. Moreover, these cells differentiated into cells of all three germ layers and showed significantly higher levels of α 2-6 sialic acid (Sia)-specific lectins, known as differentiation potential markers of human MSCs, than ADSCs. LTT-tolerant cells had a normal karyotype and had low telomerase activity, showing little carcinogenetic potency. LTT-tolerant cells also showed significantly increased activity of transmigration in the presence of chemoattractants and had increased expression of migration-related genes compared with ADSCs. In addition, LTT-tolerant cells had stronger suppressive activity against mitogen-stimulated lymphocyte proliferation than ADSCs. Overall, these results indicated that the LTT-tolerant cells in canine ADSCs have similar properties as human Muse cells (although one of the undifferentiated markers is different) and are expected to be a promising tool for regenerative therapy in dogs.

Therapeutic benefit of Muse cells in a mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron loss. Muse cells are endogenous reparative pluripotent-like stem cells distributed in various tissues. They can selectively home to damaged sites after intravenous injection by sensing sphingosine-1-phosphate produced by damaged cells, then exert pleiotropic effects, including tissue protection and spontaneous differentiation into tissue-constituent cells. In G93A-transgenic ALS mice, intravenous injection of 5.0 × 10⁴ cells revealed successful homing of human-Muse cells to the lumbar spinal cords, mainly at the pia-mater and underneath white matter, and exhibited glia-like morphology and GFAP expression. In contrast, such homing or differentiation were not recognized in human mesenchymal stem cells but were instead distributed mainly in the lung. Relative to the vehicle groups, the Muse group significantly improved scores in the rotarod, hanging-wire and muscle strength of lower limbs, recovered the number of motor neurons, and alleviated denervation and myofiber atrophy in lower limb muscles. These results suggest that Muse cells homed in a lesion site-dependent manner and protected the spinal cord against motor neuron death. Muse cells might also be a promising cell source for the treatment of ALS patients.

Regenerated nephrons in kidney cortices ameliorate exacerbated serum creatinine levels in rats with adriamycin nephropathy

Kidney regeneration could be classified into 2 groups: kidney generation and kidney repair. We have attempted in vivo nephron generation for kidney repair, as a therapy for chronic renal failure (CRF), by exploiting cellular interactions via conditioned media. In the previous report, we demonstrated the generation of rich nephrons in rat intact kidney cortices through percapsular injection of mesenchymal stem cell (MSC)-differentiated tubular epithelial cells (TECs) after pretreatment of 3-dimensional culture using a small amount of gel complex and condensed medium. In this study, to verify the amelioration of serum creatinine (sCr) levels by regenerated nephrons in rats with CRF, we first created damaged kidneys through systemic administration of adriamycin, and implanted the pretreated MSC-differentiated TECs into unilateral kidney cortices 2 weeks after adriamycin administration (A-2W, that is I-0W). After recovery of acute kidney injury, the control rats without cell implantation showed re-exacerbation of sCr levels, resulting in death within A-12W. Alternatively, the cell-implanted rats had a formation of mature nephrons in I-3W, and showed significant amelioration of sCr levels in I-7W. As a result, these rats could live until euthanization in I-12W or I-16W, indicating the utility of cell injection therapy into a kidney (K-CIT) for CRF. We expect that our K-CIT or the refined methods will be applied to patients with CRF.

Cell-Based Therapy for Stroke: Musing With Muse Cells

Stem cell-based regenerative therapies may rescue the central nervous system following ischemic stroke. Mesenchymal stem cells exhibit promising regenerative capacity in in vitro studies but display little to no incorporation in host tissue after transplantation in in vivo models of stroke. Despite these limitations, clinical trials using mesenchymal stem cells have produced some functional benefits ascribed to their ability to modulate the host's inflammatory response coupled with their robust safety profile. Regeneration of ischemic brain tissue using stem cells, however, remains elusive in humans. Multilineage-differentiating stress-enduring (Muse) cells are a distinct subset of mesenchymal stem cells found sporadically in connective tissue of nearly every organ. Since their discovery in 2010, these endogenous reparative stem cells have been investigated for their therapeutic potential against a variety of diseases, including acute myocardial infarction, stroke, chronic kidney disease, and liver disease. Preclinical studies have exemplified Muse cells' unique ability mobilize, differentiate, and engraft into damaged host tissue. Intravenously transplanted Muse cells in mouse lacunar stroke models afforded functional recovery and long-term engraftment into the host neural network. This mini-review article highlights these biological properties that make Muse cells an exceptional candidate donor source for cell therapy in ischemic stroke. Elucidating the mechanism behind the therapeutic potential of Muse cells will undoubtedly help optimize stem cell therapy for stroke and advance the field of regenerative medicine.

Regenerative potential of pluripotent nontumorgenetic stem cells: Multilineage differentiating stress enduring cells (Muse cells)

Multilineage differentiating stress enduring cells (Muse cells), double positive for SSEA-3 and CD105, can be isolated by fluorescence-activated cell sorting (FACS) or sever cellular conditions from dermal fibroblasts, bone marrow stem cells (BMSCs), adipose tissue derived stem cells (ADSCs), fresh bone marrow and liposuction fat. When cultured in a single-cell suspension, Muse cells can grow into characteristic cell clusters. Muse cells maintain pluripotency as evidenced by pluripotent markers in vitro. Besides, Muse cells have no tumorigenesis up to 6 months in SCID mice. Muse cells differentiate into cells representative of all three germ layers both spontaneously and under specific induction. In comparison to mesenchymal stem cells (MSCs), Muse cells show higher homing and migration capabilities to damaged sites which is predominantly attributed to S1P–S1PR2 axis. The regenerative effects of Muse cells have been demonstrated by many models in vivo or in vitro, including stroke, intracerebral hemorrhage, myocardial infarction, aortic aneurysm, lung injuries, liver fibrosis, focal segmental glomerulosclerosis, osteochondral defects and skin ulcer. In general, migration, differentiation and paracrine play a pivotal role in the regeneration capability. Here we review the isolation, core properties, preclinical studies as well as the underling molecular and cellular details to highlight their regenerative potential.

Transplantation of human dental pulp stem cells in streptozotocin-induced diabetic rats

Type 1 diabetes mellitus (T1DM) is a chronic metabolic disease caused by the destruction of pancreatic β-cells. Human dental pulp stem cells represent a promising source for cell-based therapies, owing to their easy, minimally invasive surgical access, and high proliferative capacity. It was reported that human dental pulp stem cells can differentiate into a pancreatic cell lineage in vitro; however, few studies have investigated their effects on diabetes. Our study aimed to investigate the therapeutic potential of intravenous and intrapancreatic transplantation of human dental pulp stem cells in a rat model of streptozotocin-induced type 1 diabetes. Forty Sprague Dawley male rats were randomly categorized into four groups: control, diabetic (STZ), intravenous treatment group (IV), and intrapancreatic treatment group (IP). Human dental pulp stem cells (1 × 10⁶ cells) or vehicle were injected into the pancreas or tail vein 7 days after streptozotocin injection. Fasting blood glucose levels were monitored weekly. Glucose tolerance test, rat and human serum insulin and C-peptide, pancreas histology, and caspase-3, vascular endothelial growth factor, and Ki67 expression in pancreatic tissues were assessed 28 days post-transplantation. We found that both IV and IP transplantation of human dental pulp stem cells reduced blood glucose and increased levels of rat and human serum insulin and C-peptide. The cells engrafted and survived in the streptozotocin-injured pancreas. Islet-like clusters and scattered human dental pulp stem cells expressing insulin were observed in the pancreas of diabetic rats with some difference in the distribution pattern between the two injection routes. RT-PCR analyses revealed the expression of the human-specific pancreatic β-cell genes neurogenin 3 (NGN3), paired box 4 (PAX4), glucose transporter 2 (GLUT2), and insulin in the pancreatic tissues of both the IP and IV groups. In addition, the transplanted cells downregulated the expression of caspase-3 and upregulated the expression of vascular endothelial growth factor and Ki67, suggesting that the injected cells exerted pro-angiogenetic and antiapoptotic effects, and promoted endogenous β-cell replication. Our study is the first to show that human dental pulp stem cells can migrate and survive within streptozotocin-injured pancreas, and induce antidiabetic effects through the differentiation and replacement of lost β-cells and paracrine-mediated pancreatic regeneration. Thus, human dental pulp stem cells may have therapeutic potential to treat patients with long term T1DM.

Regeneration of pulpo-dentinal-like complex by a group of unique multipotent CD24a+ stem cells

Dental pulp is critical to maintain the vitality of a tooth. Regeneration of pulpo-dentinal complex is of great interest to treat pulpitis and pulp necrosis. In this study, through three-dimensional spheroid culture, a group of unique multipotent stem cells were identified from mouse dental papilla called multipotent dental pulp regenerative stem cells (MDPSCs). MDPSCs exhibited enhanced osteogenic/odontogenic differentiation capabilities and could form regenerative dentin and neurovascular-like structures that mimicked the native teeth in vivo. Further analysis revealed that CD24a was the bona fide marker for MDPSCs, and their expansion was highly dependent on the expression of a key transcriptional factor, Sp7. Last, CD24a⁺ cells could be detected in primary dental papilla in mice and human, suggesting that MDPSCs resided in their native niches. Together, our study has identified a previously unidentified group of multipotent pulp regenerative stem cells with defined molecular markers for the potential treatment of pulpitis and pulp necrosis.

Intravenously Transplanted Human Multilineage-Differentiating Stress-Enduring Cells Afford Brain Repair in a Mouse Lacunar Stroke Model

Background and Purpose—

Multilineage-differentiating stress-enduring cells are endogenous nontumorigenic reparative pluripotent-like stem cells found in bone marrow, peripheral blood, and connective tissues. Topically administered human multilineage-differentiating stress-enduring cells into rat/mouse stroke models differentiated into neural cells and promoted clinically relevant functional recovery. However, critical questions on the appropriate timing and dose, and safety of the less invasive intravenous administration of clinical-grade multilineage-differentiating stress-enduring cell–based product CL2020 remain unanswered.

Methods—

Using an immunodeficient mouse lacunar model, CL2020 was administered via the cervical vein in different doses (high dose=5×10 4 cells/body; medium dose=1×10 4 cells/body; low dose=5×10 3 cells/body) at subacute phase (≈9 days after onset) and chronic phase (≈30 days). Cylinder test, depletion of human cells by diphtheria toxin administration, immunohistochemistry, and human specific-genome detection were performed.

Results—

Tumorigenesis and adverse effects were not detected for up to 22 weeks. The high-dose group displayed significant functional recovery compared with the vehicle group in cylinder test in subacute-phase–treated and chronic-phase–treated animals after 6 weeks and 8 weeks post-injection, respectively. In the high-dose group of subacute-phase–treated animals, robust and stable recovery in cylinder test persisted up to 22 weeks compared with the vehicle group. In both groups, intraperitoneal injection of diphtheria toxin abrogated the functional recovery. Anti-human mitochondria revealed CL2020 distributed mainly in the peri-infarct area at 1, 10, and 22 weeks and expressed NeuN (neuronal nuclei)- and MAP-2 (microtubule-associated protein-2)-immunoreactivity.

Conclusions—

Intravenously administered CL2020 was safe, migrated to the peri-infarct area, and afforded functional recovery in experimental stroke.

Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice

Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection.

[Hantavirus infection as a risk for chronic kidney disease of unknown etiology (CKDu) in Sri Lanka]

Chronic kidney disease of unknown etiology (CKDu) has emerged in endemic areas of Sri Lanka since the 1990s. The disease is a chronic but fatal disease. Until now, heavy metals and agrochemicals have been suspected as the cause of CKDu, but it has been still unknown. Recently, we have found a high seroprevalence to hantavirus in CKDu patients and reported that hantavirus infection is a risk of CKDu. Hantaviruses are rodent-borne zoonotic viruses. Here, I would like to introduce a story of the research from sero-epidemiology to the search for host animals.

Transplantation of Mouse Induced Pluripotent Stem Cell-Derived Podocytes in a Mouse Model of Membranous Nephropathy Attenuates Proteinuria

Injury to podocytes is a principle cause of initiation and progression of both immune and non-immune mediated glomerular diseases that result in proteinuria and decreased function of the kidney. Current advances in regenerative medicine shed light on the therapeutic potential of cell-based strategies for treatment of such disorders. Thus, there is hope that generation and transplantation of podocytes from induced pluripotent stem cells (iPSCs), could potentially be used as a curative treatment for glomerulonephritis caused by podocytes injury and loss. Despite several reports on the generation of iPSC-derived podocytes, there are rare reports about successful use of these cells in animal models. In this study, we first generated a model of anti-podocyte antibody-induced heavy proteinuria that resembled human membranous nephropathy and was characterized by the presence of sub-epithelial immune deposits and podocytes loss. Thereafter, we showed that transplantation of functional iPSC-derived podocytes following podocytes depletion results in recruitment of iPSC-derived podocytes within the damaged glomerulus, and leads to attenuation of proteinuria and histological alterations. These results provided evidence that application of iPSCs-derived renal cells could be a possible therapeutic strategy to favorably influence glomerular diseases outcomes.