Stem Cells from Human Exfoliated Deciduous Teeth Ameliorate Diabetic Nephropathy In Vivo and In Vitro by Inhibiting Advanced Glycation End Product-Activated Epithelial-Mesenchymal Transition

The therapeutic effect of mesenchymal stem cells in diabetic kidney disease

Diabetes mellitus (DM) often causes chronic kidney damage despite best medical practices. Diabetic kidney disease (DKD) arises from a complex interaction of factors within the kidney and the whole body. Targeting specific disease-causing agents using drugs has not been effective in treating DKD. However, stem cell therapies offer a promising alternative by addressing multiple disease pathways and promoting kidney regeneration. Mesenchymal stem cells (MSCs) offer great promise due to their superior accessibility ratio from adult tissues and remarkable modes of action, such as the production of paracrine anti-inflammatory and cytoprotective substances. This review critically evaluates the development of MSC treatment for DKD as it moves closer to clinical application. Results from animal models suggest that systemic MSC infusion may positively impact DKD progression. However, few registered and completed clinical trials exist, and whether the treatments are effective in humans is still being determined. Significant knowledge gaps and research opportunities exist, including establishing the ideal source, dose, and timing of MSC delivery, better understanding of in vivo mechanisms, and developing quantitative indicators to obtain a more significant therapeutic response. This paper reviews recent literature on using MSCs in preclinical and clinical trials in DKD. Potent biomarkers related to DKD are also highlighted, which may help better understand MSCs' action in this disease progression. KEY MESSAGES: Mesenchymal stem cells have anti-inflammatory and paracrine effects in diabetic kidney disease. Mesenchymal stem cells alleviate in animal models having diabetic kidney disease. Mesenchymal stem cells possess promise for the treatment of diabetic kidney disease.

The therapeutic effect of mesenchymal stem cells in diabetic kidney disease

Abstract

Diabetes mellitus (DM) often causes chronic kidney damage despite best medical practices. Diabetic kidney disease (DKD) arises from a complex interaction of factors within the kidney and the whole body. Targeting specific disease-causing agents using drugs has not been effective in treating DKD. However, stem cell therapies offer a promising alternative by addressing multiple disease pathways and promoting kidney regeneration. Mesenchymal stem cells (MSCs) offer great promise due to their superior accessibility ratio from adult tissues and remarkable modes of action, such as the production of paracrine anti-inflammatory and cytoprotective substances. This review critically evaluates the development of MSC treatment for DKD as it moves closer to clinical application. Results from animal models suggest that systemic MSC infusion may positively impact DKD progression. However, few registered and completed clinical trials exist, and whether the treatments are effective in humans is still being determined. Significant knowledge gaps and research opportunities exist, including establishing the ideal source, dose, and timing of MSC delivery, better understanding of in vivo mechanisms, and developing quantitative indicators to obtain a more significant therapeutic response. This paper reviews recent literature on using MSCs in preclinical and clinical trials in DKD. Potent biomarkers related to DKD are also highlighted, which may help better understand MSCs’ action in this disease progression.

Key messages

An overview of the efficacy and signaling pathways activated by stem cell-derived extracellular vesicles in diabetic kidney disease

Diabetic kidney disease (DKD) is one of complications of diabetes mellitus with severe microvascular lesion and the most common cause of end-stage chronic kidney disease (ESRD). Controlling serum glucose remains the primary approach to preventing and slowing the progression of DKD. Despite considerable efforts to control diabetes, people with diabetes develop not only DKD but also ESRD. The pathogenesis of DKD is very complex, and current studies indicate that mesenchymal stromal cells (MSCs) regulate complex disease processes by promoting pro-regenerative mechanisms and inhibiting multiple pathogenic pathways. Extracellular vesicles (EVs) are products of MSCs. Current data indicate that MSC-EVs-based interventions not only protect renal cells, including renal tubular epithelial cells, podocytes and mesangial cells, but also improve renal function and reduce damage in diabetic animals. As an increasing number of clinical studies have confirmed, MSC-EVs may be an effective way to treat DKD. This review explores the potential efficacy and signaling pathways of MSC-EVs in the treatment of DKD.

Comparison of the Angiogenic Ability between SHED and DPSC in a Mice Model with Critical Limb Ischemic

BACKGROUND

Regenerative medicine by using stem cells from dental pulp is promising for treating patients with critical limb ischemic (CLI). Here, we investigated the difference in the angiogenetic ability of stem cells from human exfoliated deciduous teeth (SHED) and human dental pulp stem cells (DPSC).

METHODS

SHED and DPSC were harvested from dental pulp and analyzed in flow- cytometry for detecting the expression of surface markers. Levels of angiogenetic marker were examined by RT-PCR and Western-blot. Eighteen immunodeficient mice of critical limb ischemic model were divided into three groups: SHED, DPSC and saline, which was administered with SHED, DPSC or saline intramuscularly. Histological examination was performed to detect the regenerative results.

RESULTS

A highly expression of CD146 was detected in SHED. Moreover, cells with negative expression of both CD146 and CD31 in SHED were more in comparison with those in DPSC. Expression of angiogenesis factors including CXCL12, CXCR4, Hif-1a, CD31, VEGF and bFGF were significant higher in SHED than DPSC by the RT-PCR and Western-Blot results. SHED induced more CD31 expression and less fibrous tissue formation in the critical limb ischemic model as compare with DPSC and saline.

CONCLUSION

Both SHED and DPSC possessed the ability of repairing CLI. With expressing more proangiogenesis factors, SHED may have the advantage of repairing CLI.

Multipotency and Immunomodulatory Benefits of Stem Cells From Human Exfoliated Deciduous Teeth

Stem cells derived from human exfoliated deciduous teeth (SHEDs) are considered a promising cell population for cell-based or cell-free therapy and tissue engineering because of their proliferative, multipotency and immunomodulator. Based on recent studies, we find that SHEDs show the superior ability of nerve regeneration in addition to the potential of osteogenesis, odontogenesis owing to their derivation from the neural crest. Besides, much evidence suggests that SHEDs have a paracrine effect and can function as immunomodulatory regents attributing to their capability of secreting cytokines and extracellular vesicles. Here, we review the characteristic of SHEDs, their multipotency to regenerate damaged tissues, specifically concentrating on bones or nerves, following the paracrine activity or immunomodulatory benefits of their potential for clinical application in regenerative medicine.

Exosomal circTAOK1 contributes to diabetic kidney disease progression through regulating SMAD3 expression by sponging miR-520h

BACKGROUND

Diabetic nephropathy (DN) is a frequent diabetes complication with complex pathogenesis. Circular RNA (circRNA) circTAOK1 (also named circ_0003928) has been reported to be upregulated in high glucose (HG)-treated human umbilical vein endothelial cells. Also, exosomal circRNAs can exert significant roles in the pathology of various diseases. This study is designed to explore the role and mechanism of exosomal circTAOK1 on the glomerular mesangial cell (GMC) injury in DN.

METHODS

Exosomes were detected by a transmission electron microscope. The protein levels of CD9, CD63, proliferating cell nuclear antigen (PCNA), cyclinD1, α-SMA, fibronectin, E-cadherin, N-cadherin, and SMAD family member 3 (SMAD3) were examined by western blot assay. circTAOK1, microRNA-520h (miR-520h), and SMAD3 levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation and cell cycle progression were detected by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays. The binding relationship between miR-520h and circTAOK1 or SMAD3 was predicted by Starbase and then verified by a dual-luciferase reporter and RNA immunoprecipitation (RIP), RNA pull-down assays.

RESULTS

CircTAOK1 expression was upregulated in the exosomes isolated from HG-treated glomerular epithelial cells (GEC). Moreover, GEC-circTAOK1-Exo could promote proliferation, fibrosis, and epithelial-mesenchymal transition (EMT) of glomerular mesangial cells (GMCs). Mechanically, circTAOK1 could regulate SMAD3 expression by sponging miR-520h, GEO-si-circTAOK1 Exo-induced miR-520h and repressed SMAD3 expression in GMC.

CONCLUSION

GEC-circTAOK1-Exo could boost proliferation, fibrosis, and EMT of GMC through targeting the miR-520h/SMAD3 axis, providing new insights into the pathogenesis of DN.

Chondrogenic Potential of Dental-Derived Mesenchymal Stromal Cells

The field of tissue engineering has revolutionized the world in organ and tissue regeneration. With the robust research among regenerative medicine experts and researchers, the plausibility of regenerating cartilage has come into the limelight. For cartilage tissue engineering, orthopedic surgeons and orthobiologists use the mesenchymal stromal cells (MSCs) of various origins along with the cytokines, growth factors, and scaffolds. The least utilized MSCs are of dental origin, which are the richest sources of stromal and progenitor cells. There is a paradigm shift towards the utilization of dental source MSCs in chondrogenesis and cartilage regeneration. Dental-derived MSCs possess similar phenotypes and genotypes like other sources of MSCs along with specific markers such as dentin matrix acidic phosphoprotein (DMP) -1, dentin sialophosphoprotein (DSPP), alkaline phosphatase (ALP), osteopontin (OPN), bone sialoprotein (BSP), and STRO-1. Concerning chondrogenicity, there is literature with marginal use of dental-derived MSCs. Various studies provide evidence for in-vitro and in-vivo chondrogenesis by dental-derived MSCs. With such evidence, clinical trials must be taken up to support or refute the evidence for regenerating cartilage tissues by dental-derived MSCs. This article highlights the significance of dental-derived MSCs for cartilage tissue regeneration.

Sinking Our Teeth in Getting Dental Stem Cells to Clinics for Bone Regeneration

Dental stem cells have been isolated from the medical waste of various dental tissues. They have been characterized by numerous markers, which are evaluated herein and differentiated into multiple cell types. They can also be used to generate cell lines and iPSCs for long-term in vitro research. Methods for utilizing these stem cells including cellular systems such as organoids or cell sheets, cell-free systems such as exosomes, and scaffold-based approaches with and without drug release concepts are reported in this review and presented with new pictures for clarification. These in vitro applications can be deployed in disease modeling and subsequent pharmaceutical research and also pave the way for tissue regeneration. The main focus herein is on the potential of dental stem cells for hard tissue regeneration, especially bone, by evaluating their potential for osteogenesis and angiogenesis, and the regulation of these two processes by growth factors and environmental stimulators. Current in vitro and in vivo publications show numerous benefits of using dental stem cells for research purposes and hard tissue regeneration. However, only a few clinical trials currently exist. The goal of this review is to pinpoint this imbalance and encourage scientists to pick up this research and proceed one step further to translation.

Study of the Active Components and Molecular Mechanism of Tripterygium wilfordii in the Treatment of Diabetic Nephropathy

We aimed to explore the active ingredients and molecular mechanism of Tripterygium wilfordii (TW) in the treatment of diabetic nephropathy (DN) through network pharmacology and molecular biology. First, the active ingredients and potential targets of TW were obtained through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and related literature materials, and Cytoscape 3.7.2 software was used to construct the active ingredient-target network diagram of TW. Second, the target set of DN was obtained through the disease database, and the potential targets of TW in the treatment of DN were screened through a Venn diagram. A protein interaction network diagram (PPI) was constructed with the help of the String platform and Cytoscape 3.7.2. Third, the ClueGO plug-in tool was used to enrich the GO biological process and the KEGG metabolic pathway. Finally, molecular docking experiments and cell pathway analyses were performed. As a result, a total of 52 active ingredients of TW were screened, and 141 predicted targets and 49 target genes related to DN were identified. The biological process of GO is mediated mainly through the regulation of oxygen metabolism, endothelial cell proliferation, acute inflammation, apoptotic signal transduction pathway, fibroblast proliferation, positive regulation of cyclase activity, adipocyte differentiation and other biological processes. KEGG enrichment analysis showed that the main pathways involved were AGE-RAGE, vascular endothelial growth factor, HIF-1, IL-17, relaxin signalling pathway, TNF, Fc epsilon RI, insulin resistance and other signaling pathways. It can be concluded that TW may treat DN by reducing inflammation, reducing antioxidative stress, regulating immunity, improving vascular disease, reducing insulin resistance, delaying renal fibrosis, repairing podocytes, and reducing cell apoptosis, among others, with multicomponent, multitarget and multisystem characteristics.

Mesenchymal Stem Cells: An Overview of Their Potential in Cell-Based Therapy for Diabetic Nephropathy

Diabetic nephropathy (DN) is a devastating complication associated with diabetes mellitus, and it is the leading cause of end-stage renal diseases (ESRD). Over the last few decades, numerous studies have reported the beneficial effects of stem cell administration, specifically mesenchymal stem or stromal cells (MSCs), on tissue repair and regeneration. MSC therapy has been considered a promising strategy for ameliorating the progression of DN largely based on results obtained from several preclinical studies and recent Phase I/II clinical trials. This paper will review the recent literature on MSC treatment in DN. In addition, the roles and potential mechanisms involved in MSC treatment of DN will be summarized, which may present much needed new drug targets for this disease. Moreover, the potential benefits and related risks associated with the therapeutic action of MSCs are elucidated and may help in achieving a better understanding of MSCs.

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.

Chrysophanol Inhibits the Progression of Diabetic Nephropathy via Inactivation of TGF-β Pathway

Background

Diabetic nephropathy (DN) is a common form of diabetic complication which threatens the health of patients with diabetes. It has been reported that chrysophanol (CHR) can alleviate the progression of diabetes; however, the role of CHR in DN remains unclear.

Methods

To mimic DN in vitro, human podocytes (AB8/13 cells) were treated with high glucose (HG). Meanwhile, Western blot was performed to detect protein expressions. CCK-8 assay was used to test cell viability and cell proliferation was detected by Ki-67 staining. In addition, flow cytometry was performed to investigate cell apoptosis and cycle and cell migration was tested by transwell assay. Moreover, in vivo model of DN was established to detect the effect of CHR on DN in vivo.

Results

HG-induced AB8/13 cell growth inhibition was significantly rescued by CHR. In addition, HG notably promoted the migration of AB8/13 cells, while this phenomenon was obviously reversed by CHR. Moreover, CHR inhibited the progression of DN via inactivation of TGF-β/EMT axis. Furthermore, CHR alleviated the symptom of DN in vivo.

Conclusion

CHR significantly alleviated the progression of DN via inactivation of TGF-β/EMT signaling in vitro and in vivo. Our findings were helpful to uncover the mechanism by which CHR regulates DN, as well as inspire the development of novel therapy against DN.

LncRNA H19 Inhibits the Progression of Sepsis-Induced Myocardial Injury via Regulation of the miR-93-5p/SORBS2 Axis

Sepsis is an infectious disease that seriously endangers human health. It usually leads to myocardial injury which seriously endangers to the health of human beings. H19 has been confirmed to play key roles in various diseases, including sepsis. However, its function in the progression of sepsis-induced myocardial injury remains largely unknown. H9C2 cells were treated with lipopolysaccharide (LPS) to mimic sepsis-induced myocardial injury in vitro. Cell proliferation and apoptosis were detected by MTT assay and flow cytometry, respectively. In addition, gene and protein expression levels in H9C2 cells were measured by quantitative real-time PCR (qRT-PCR) and Western blotting. The levels of inflammatory cytokines in H9C2 cell supernatants were tested by ELISA. JC-1 staining was performed to observe the mitochondrial membrane potential level in H9C2 cells. H19 and SORBS2 were downregulated in H9C2 cells following LPS treatment, while miR-93-5p was upregulated. Moreover, LPS-induced cell growth inhibition and mitochondrial damage were significantly reversed by overexpression of H19. In addition, H19 upregulation notably suppressed LPS-induced inflammatory responses in H9C2 cells. Moreover, H19 sponged miR-93-5p to promote SORBS2 expression. Overall, H19 suppressed sepsis-induced myocardial injury via regulation of the miR-93-5p/SORBS2 axis. H19 attenuated the development of sepsis-induced myocardial injury in vitro via modulation of the miR-93-5p/SORBS2 axis. Thus, H19 could serve as a potential target for the treatment of sepsis-induced myocardial injury.

Potential Application of Human β-Defensin 4 in Dental Pulp Repair

When pulp tissue is damaged by caries or trauma, vital pulp therapy (VPT) can help preserve the pulp tissue for long-term retention of teeth. However, the choice of pulp capping agent used in VPT is important for the successful preservation of the pulp tissue. Here we investigated the expression and biological function of human β-defensin 4 (HBD4) in dental pulp stem cells (DPSC) and explored its potential as a pulp capping agent. We examined the expression of HBD4 in DPSC in vitro using qPCR and immunofluorescence staining. We also looked at the effect of HBD4 on inflammatory factors in lipopolysaccharide (LPS)-stimulated DPSC, and its effects on mineralizing cell phenotype differentiation, via qPCR and western blot. Finally, we examined the ability of HBD4 to promote the restoration of the pulp-dentin complex in vivo, using male Wistar rats with reversible pulpitis. We found HBD4 was highly expressed in DPSC stimulated by TNF-α and IL-1α. HBD4 down-regulated the expression of inflammatory mediators (i.e., IL-1α, IL-1β, IL-6, TNF-α) in LPS-stimulated DPSC, and suppressed MAPK activity and the NF-κB pathway. HBD4 also enhanced the differentiation of DPSC into osteoblasts or odontoblasts, potentially by modulating the Notch pathway. Furthermore, HBD4 controlled the degree of pulp inflammation in a rat model of reversible pulpitis and induced the formation of restorative dentin. Together our findings indicate HBD4 may be a useful pulp capping agent for use in VPT.