Proliferation Of Renal Tubular Cells Research Articles

Urinary Epidermal Growth Factor Level as a Noninvasive Indicator of Tubular Repair in Patients with Acute Kidney Injury.

Epidermal growth factor (EGF), an essential factor for the proliferation and survival of renal tubular cells, is expressed by distal tubules and normally excreted via urine. Previous studies in rats demonstrated that acute tubular injury reduces urinary EGF levels. However, it is unclear whether urinary EGF is a suitable monitoring marker of tubular repair status after acute kidney injury (AKI) in humans. To address this question, we measured serum and urinary EGF in patients with AKI (n = 99) using ELISA and investigated whether urinary EGF levels were associated with the severity of tubular injury and renal prognosis. Urinary EGF was abundant in healthy controls but showed a significant decrease in AKI patients (14,522 ± 2190 pg/mL vs. 3201 ± 459.7 pg/mL, p < 0.05). The urinary EGF level in patients with renal AKI was notably lower than that in patients with pre-renal AKI. Furthermore, the urinary EGF level in patients with AKI stage 3 was significantly lower than that in patients with AKI stage 1. Urinary EGF levels were negatively correlated with urinary β-2MG and serum creatinine levels but positively correlated with hemoglobin levels and eGFR. Urinary EGF was not significantly correlated with urinary NAG, α-1MG, L-FABP, NGAL, KIM-1, or urinary protein concentrations. No significant correlation was observed between serum and urinary EGF levels, suggesting that urinary EGF is derived from the renal tubules rather than the blood. In living renal transplantation donors, the urinary EGF/Cr ratio was approximately half the preoperative urinary EGF/Cr ratio after unilateral nephrectomy. Collectively, these data suggest that urinary EGF is a suitable noninvasive indicator of not only the volume of functional normal renal tubules but also the status of tubular repair after AKI.

Molecular mechanism of Gan-song Yin inhibiting the proliferation of renal tubular epithelial cells by regulating miR-21-5p in adipocyte exosomes

Ethnopharmacological relevanceGan-song Yin is derived from the classic ancient prescription " Gan-song pill " for the treatment of wasting-thirst in Ningxia combined with the characteristic “fragrant medicine”. It is clinically used for the treatment of early renal fibrosis caused by diabetic nephropathy. Previous studies have shown that it has a good effect and great potential in the prevention and treatment of diabetic nephropathy, but its mechanism research is still limited. Aim of the studyTo investigate the mechanism of GSY to improve DN by interfering with miR-21-5p and glycolipid metabolism in adipocyte exosomes using 3T3-L1 and TCMK-1 co-culture system. Materials and methodsThe co-culture system of 3T3-L3 and TCMK-1 was established, the IR model was established, and the stability, lipid drop change, glucose consumption, triglyceride content, cell viability, cell cycle and apoptosis level, protein content and mRNA expression of the IR model were detected. ResultsGSY inhibited 3T3-L1 activity, increased glucose consumption and decreased TG content. Decreased TCMK-1 cell viability, inhibited apoptosis, cell cycle arrest occurred in G0/G1 phase and S phase. Adipocyte IR model and co-culture system were stable within 48 h. After GSY intervention, lipid droplet decomposition and glucose consumption increased. The TG content of adipocytes increased, while the TG content of co-culture system decreased. GSY can regulate the expression of TGF-β1/SMAD signaling pathway protein in IR state. After GSY intervention, the expression of miR-21-5p was increased in 3T3-L1 and Exo cells, and decreased in TCMK-1 cells. ConclusionsGSY can regulate TGF-β1/SMAD signaling pathway through the secretion of miR-21-5p from adipocytes, protect IR TCMK-1, regulate the protein and mRNA expression levels of PPARγ, GLUT4, FABP4, and improve glucose and lipid metabolism.

COL28 promotes proliferation, migration, and EMT of renal tubular epithelial cells

Type XXVIII collagen (COL28) is involved in cancer and lung fibrosis. COL28 polymorphisms and mutations might be involved in kidney fibrosis, but the exact role of COL28 in renal fibrosis is unknown. This study explored the function of COL28 in renal tubular cells by examining the expression of COL28 mRNA and the effects of COL28 overexpression in human tubular cells. COL28 mRNA expression and localization were observed in normal and fibrotic kidney tissues from humans and mice using real-time PCR, western blot, immunofluorescence, and immunohistochemistry. The consequences of COL28 overexpression on cell proliferation, migration, cell polarity, and epithelial-to-mesenchymal transition (EMT) induced by TGF-β1 were examined in human tubular HK-2 cells. COL28 expression was low in human normal renal tissues, mainly observed in the renal tubular epithelial cells and especially in proximal renal tubules. COL28 protein expression in human and mouse obstructive kidney disease was higher than in normal tissues (p < 0.05) and more significant in the UUO2-Week than the UUO1-Week group. The overexpression of COL28 promoted HK-2 cell proliferation and enhanced their migration ability (all p < 0.05). TGF-β1 (10 ng/ml) induced COL28 mRNA expression in HK-2 cells, decreased E-cadherin and increased α-SMA in the COL28-overexpression group compared with controls (p < 0.05). ZO-1 expression decreased while COL6 increased in the COL28-overexpression group compared with controls (p < 0.05). In conclusion, COL28 overexpression promotes the migration and proliferation of renal tubular epithelial cells. The EMT could also be involved. COL28 could be a therapeutic target against renal- fibrotic diseases.

Downregulation of KLF10 contributes to the regeneration of survived renal tubular cells in cisplatin-induced acute kidney injury via ZBTB7A-KLF10-PTEN axis

Acute kidney injury (AKI) is a common clinical dysfunction with complicated pathophysiology and limited therapeutic methods. Renal tubular injury and the following regeneration process play a vital role in the course of AKI, but the underlining molecular mechanism remains unclear. In this study, network-based analysis of online transcriptional data of human kidney found that KLF10 was closely related to renal function, tubular injury and regeneration in various renal diseases. Three classical mouse models confirmed the downregulation of KLF10 in AKI and its correlation with tubular regeneration and AKI outcome. The 3D renal tubular model in vitro and fluorescent visualization system of cellular proliferation were constructed to show that KLF10 declined in survived cells but increased during tubular formation or conquering proliferative impediment. Furthermore, overexpression of KLF10 significantly inhibited, whereas knockdown of KLF10 extremely promoted the capacity of proliferation, injury repairing and lumen-formation of renal tubular cells. In mechanism, PTEN/AKT pathway were validated as the downstream of KLF10 and participated in its regulation of tubular regeneration. By adopting proteomic mass spectrum and dual-luciferase reporter assay, ZBTB7A were found to be the upstream transcription factor of KLF10. Our findings suggest that downregulation of KLF10 positively contributed to tubular regeneration in cisplatin induced acute kidney injury via ZBTB7A-KLF10-PTEN axis, which gives insight into the novel therapeutic and diagnostical target of AKI.

Ustiloxin A inhibits proliferation of renal tubular epithelial cells in vitro and induces renal injury in mice by disrupting structure and respiratory function of mitochondria

Recently, we found that Ustiloxin A (UA, a mycotoxin) was widely detected in paddy environment and rice samples from several countries, and was also detected in human urine samples from China. However, the current knowledge about the health risks of UA are limited. In this research, the cytotoxicity of UA in mice renal tubular epithelial cells (mRTECs) was evaluated, and the results indicated that UA arrested cell cycle in G2/M phase via altering cellular morphology and microtubule, and inhibited the proliferation and division of mRTECs. Furthermore, UA could inhibit mitochondrial respiration via binding to the CoQ-binding site in dihydro-orotate dehydrogenase (DHODH) protein, and resulted in mitochondrial damage. These adverse effects of UA on mitochondria might be responsible for the cytotoxicity observed in vitro. In vivo, UA at concentrations that were comparable to the realistic concentrations of human exposure induced renal insufficiency in mice, and this might be associated with the renal mitochondrial damage in mice. However, exposure to UA at those realistic concentrations did not promote the progression from renal insufficiency to renal fibrosis and chronic kidney disease was not observed in mice.

Fibromyxoid Nephrogenic Adenoma: A Series of 43 Cases Reassessing Predisposing Conditions, Clinical Presentation, and Morphology.

Nephrogenic adenoma is a benign epithelial lesion of the genitourinary tract that arises from the reimplantation and proliferation of shed renal tubular cells in areas of urothelial injury and denudation. Fibromyxoid nephrogenic adenoma is a rare variant that consists of compressed spindle-shaped renal epithelial cells in a fibromyxoid background. Only 14 observations of this variant are reported in the literature. We performed a retrospective analysis of fibromyxoid nephrogenic adenomas from 3 large reference centers. We identified 43 lesions in 6 women and 36 men (2 in 1 man) with a median age of 72 years (range, 31 to 94y). Median lesion size was 0.7cm (range, 0.2 to 5cm). Nephrogenic adenomas were in the bladder (n=15), prostate/prostatic urethra (n=14), kidney (n=7), ureter (n=3), penile urethra (n=3), and urethral diverticulum (n=1). One of the kidney lesions developed in an end-stage kidney and radiologically mimicked cancer. Of 37 patients with information, 36 had predisposing conditions including prior biopsy, transurethral resection of bladder tumor, resection, Foley catheter, BCG treatment, urinary stones, (chemo)radiation, or diverticulum. Only 4/37 (10.8%) had a history of prior irradiation. Fifteen lesions had pure fibromyxoid morphology and 28 were admixed classic and fibromyxoid patterns. Three nephrogenic adenomas involved prostatic stroma, 3 renal sinus fat, 2 muscularis propria (1 bladder, 1 renal pelvis), 1 perinephric fat, and 1 corpus spongiosum. Ten fibromyxoid nephrogenic adenomas were intermixed with urothelial carcinoma, 1 with prostate adenocarcinoma, and 1 with malignant melanoma. By immunohistochemistry, PAX8 was positive in all the examined lesions (n=31). Napsin A was negative in all examined fibromyxoid nephrogenic adenomas (n=30). Twenty of them had classic nephrogenic adenoma component which was positive for napsin A. Similar to classic nephrogenic adenoma, fibromyxoid nephrogenic adenoma can occur anywhere along the urinary tract and is associated with a prior history that causes urothelial injury. In nearly a quarter of the cases, fibromyxoid nephrogenic adenoma extended beyond the lamina propria. Unlike previously suggested, fibromyxoid nephrogenic adenoma is not specifically related to prior radiation therapy. Awareness of this variant is important to avoid misdiagnosis and overtreatment.

404.7: Study on the Regulatory Effect of iPS-Derived Exosomes on the Local Immune Microenvironment in DCD Kidney Transplanted Rats

Introduction: Ischemia reperfusion injury (IRI) of donation After Cardiac death (DCD) transplanted kidney is the key factor of acute renal injury, acute and chronic rejection of renal transplantation and transplanted kidney disease.The latest researches show that mesenchymal stem cells (MSCs) have the function of protecting damaged tissues and organs and strong immune regulation. Induced pluripotent stem (iPS) cells have higher proliferative capacity and exosome secretion potential than MSCs. In addition to the functions of stem cells, exosomes have the unique ability to cross the blood-brain barrier and deliver remotely, which means that exosomes have better advantages in clinical disease treatment compared with the therapeutic potential of stem cells. Therefore, the main purpose of this study is to clarify the role of IPS derived exosomes in protecting the IRI of DCD transplanted kidney and regulating its local immune microenvironment. Methods: The iPS cells were passaged to the third passage and massively expanded. After 48 hours of culture, 100 mL of cell culture supernatant was collected and exosomes were extracted from the supernatant by the kit method, and the morphology and surface membrane marker proteins of the exosomes were identified. The SD rats were established with DCD renal transplantation model and 10, 50, and 100 μg of exosomes were infused into that SD rats respectively, and a PBS control group was set at the same time. On the 3rd, 5th, 7th, 14th and 28th days after transplantation, the content of cytokines in the serum of the recipient rats, the proportion of lymphocyte subsets CD4+CD25+Foxp3+Tregs in the spleen and the relative expression of Foxp3 mRNA were detected. The proliferation of renal tubular cells was detected by PCNA immunofluorescence. The pathological changes of renal tissue were determined by HE staining, and the apoptosis of renal tubular epithelial cells was detected by Tunel staining. The infiltration of inflammatory cells was detected by immunohistochemistry. The expression changes of regulatory T cells in renal tissue and macrophage phenotypic characteristics were analyzed by flow cytometry. Results: The experimental amount of exosomes was successfully obtained, and the morphology was observed by transmission electron microscope. The exosomes were round or oval membranous vesicles with uniform size, and the edges were clearly visible. The TSG101, CD63, and CD9 proteins were highly expressed on the exosome membrane surface by western-blot. A DCD rat kidney transplantation model was successfully established. The expression levels of IL-12, IL-2, IFN-γ, and TNF-α in the serum of each group were increased to varying degrees from the 3rd day after operation. On the 3rd and 7th days, the levels of IL-12, IL-2, IFN-γ, and TNF-α in the 100 μg exosome infusion group were significantly lower than those in the 10 μg, 50 μg and PBS groups (P<0.05), and the expression level of IL-10 in the 100 μg exosome infusion group was significantly higher than 10μg, 50μg and PBS groups (P<0.05). On the 28th day, the expression level of IL-10 in the 100 μg exosome infusion group was significantly higher than other groups (P<0.01). Compared with other groups, the CD4+CD25+Tregs and CD4+CD25+Foxp3+Tregs accounted for the highest proportion of CD4+T cells in the spleen of the 100μg infusion group (P<0.05). On the 28th day, the expression level of Foxp3 mRNA in the 100 μg infusion group was significantly higher than that in the 50 μg group (P<0.05). The stainings of PCNA, HE and Tunel showed that SD rats infused with 100μg exosomes could significantly reduce the pathological damage, inflammatory response and apoptosis of renal tubular epithelial cells in the transplanted kidney, promote the proliferation of renal tubular epithelial cells, and have a protective effect on IRI kidney. On the 28th day, the expression of CD4+CD25+Foxp3+Tregs cells in the transplanted kidney tissue was significantly increased, which further promoted the differentiation of macrophages into the immunomodulatory M2 subset. Conclusions: The infusion of iPS-derived high-dose exosomes is involved in the protection of the DCD kidney transplant during IRI process, and alleviates the acute and chronic injury of the DCD kidney transplant, and promotes the formation of the local immunosuppressive microenvironment in the DCD kidney transplantation. The National Natural Science Foundation of China (No.81900686).

Class IIa histone deacetylase inhibition ameliorates acute kidney injury by suppressing renal tubular cell apoptosis and enhancing autophagy and proliferation.

Expression and function of histone deacetylases (HDACs) vary with cell types and pathological conditions. Our recent studies showed that pharmacological targeting class IIa HDACs attenuated renal fibrosis, but the effect of class IIa HDAC inhibition on acute kidney injury (AKI) remains unknown. In this study, we found that four class IIa HDACs (4, 5, 7, 9) were highly expressed in the kidney of folic acid (FA) and ischemia/reperfusion (I/R)-induced AKI in mice. Administration of TMP269, a potent and selective class IIa HDAC inhibitor, improved renal function and reduced tubular cell injury and apoptosis, with concomitant suppression of HDAC4 and elevation of acetyl-histone H3. Mechanistical studies showed that TMP269 treatment inhibited FA and I/R-induced caspase-3 cleavage, Bax expression and p53 phosphorylation. Conversely, TMP269 administration preserved expression of E-cadherin, BMP7, Klotho and Bcl-2 in injured kidneys. Moreover, TMP269 was effective in promoting cellular autophagy as indicated by increased expression of Atg7, beclin-1, and LC3II, and promoted renal tubular cell proliferation as shown by increased number of proliferating cell nuclear antigen-positive cells and expression of cyclin E. Finally, blocking class IIa HDACs inhibited FA-and I/R-induced phosphorylation of extracellular signal-regulated kinases 1 and 2, and p38, two signaling pathways associated with the pathogenesis of AKI. Collectively, these results suggest that pharmacological inhibition of class IIa HDACs protects against AKI through ameliorating apoptosis, enhancing autophagy and promoting proliferation of renal tubular cells by targeting multiple signaling pathways.

Yishen Capsule Alleviated Symptoms of Diabetic Nephropathy via NOD-like Receptor Signaling Pathway

PurposeTo explore the mechanism of Yishen capsule against diabetic nephropathy (DN) based on the analysis of transcriptomics.Material and MethodsSD rats (Male, SPF grade) were randomly divided into four groups, the normal group, the DN group, the Yishen capsule group and the resveratrol group. Urine and renal tissue samples were collected after feeding with physiological saline and above drugs for 8 weeks. 24-hour urine microalbumin protein was detected by ELISA. HE staining and PAS staining were performed on renal tissues. Differential gene expression in renal tissues was analyzed by transcriptome sequencing. The differentially expressed genes were analyzed by GO enrichment and KEGG enrichment, and verified by RT-PCR and immunohistochemistry staining.ResultsThe level of 24-hour urinary microalbumin in DN group was increased, while Yishen capsule treatment reversed the increasement of urinary microalbumin. Mesangial cell proliferation, matrix accumulation, edema and vacuolar degeneration of renal tubular epithelial cells and glycogen accumulation were observed in DN group. However, pathological phenotypes mentioned above were alleviated after Yisen capsule administration. This result indicates that Yishen capsule reversed pathological phenotypes of DN in rats. The expression of 261 genes were changed in Yishen capsule group compared with DN group. GO enrichment analysis and KEGG pathway analysis showed that these genes were implicated in pathways, including mineral absorption, adipocytokine signaling pathway, fatty acid biosynthesis, thyroid hormone synthesis, renin–angiotensin system, and NOD-like receptor signaling pathway. Based on previous reported study, the expression of key factors in NOD-like receptor signaling pathway was verified. RT-PCR and immunohistochemistry staining showed that the expression of NLRP3, Caspase-1 and IL-1β in renal tissues of DN group were increased (P < 0.05), which were decreased in Yishen capsule group (P < 0.05).ConclusionYishen capsule reduced microalbuminuria and alleviated pathological changes in DN rats, which may be achieved by regulating NOD-like receptor signaling pathway.

Inhibition of polycomb repressive complex 2 by targeting EED protects against cisplatin-induced acute kidney injury.

Polycomb repressive complex 2 (PRC2) is a multicomponent complex with methyltransferase activity that catalyzes trimethylation of histone H3 at lysine 27 (H3K27me3). Interaction of the epigenetic reader protein EED with EZH2, a catalytic unit of PRC, allosterically stimulates PRC2 activity. In this study, we investigated the role and underlying mechanism of the PRC2 in acute kidney injury (AKI) by using EED226, a highly selective PRC2 inhibitor, to target EED. Administration of EED226 improved renal function, attenuated renal pathological changes, and reduced renal tubular cell apoptosis in a murine model of cisplatin‐induced AKI. In cultured renal epithelial cells, treatment with either EED226 or EED siRNA also ameliorated cisplatin‐induced apoptosis. Mechanistically, EED226 treatment inhibited cisplatin‐induced phosphorylation of p53 and FOXO3a, two transcriptional factors contributing to apoptosis, and preserved expression of Sirtuin 3 and PGC1α, two proteins associated with mitochondrial protection in vivo and in vitro. EED226 was also effective in enhancing renal tubular cell proliferation, suppressing expression of multiple inflammatory cytokines, and reducing infiltration of macrophages to the injured kidney. These data suggest that inhibition of the PRC2 activity by targeting EED can protect against cisplatin‐induced AKI by promoting the survival and proliferation of renal tubular cells and inhibiting inflammatory response.

Mesenchymal Stem Cells-Derived Exosomes Ameliorate Ischemia/Reperfusion Induced Acute Kidney Injury in a Porcine Model.

Exosomes are membrane-enclosed vesicles secreted by cells, containing a variety of biologically active ingredients including proteins, nucleic acids and lipids. In this study, we investigated the therapeutic effects of the exosomes and underlying mechanisms in a miniature pig model of ischemia/reperfusion-induced acute kidney injury (I/R-AKI). The exosomes were extracted from cultured human umbilical cord derived mesenchymal stem cells (hUC-MSCs) and infused into a miniature pig model of I/R AKI. Our results showed that 120 min of unilateral ischemia followed by reperfusion and contralateral nephrectomy resulted in renal dysfunction, severe kidney damage, apoptosis and necroptosis. Intravenous infusion of one dose of exosomes collected from about 4 × 108 hUC-MSCs significantly improved renal function and reduced apoptosis and necroptosis. Administration of hUC-MSC exosomes also reduced the expression of some pro-inflammatory cytokines/chemokines, decreased infiltration of macrophages to the injured kidneys and suppressed the phosphorylation of nuclear factor-κB and signal transducer and activator of transcription 3, two transcriptional factors related to inflammatory regulation. Moreover, hUC-MSC exosomes could promote proliferation of renal tubular cells, angiogenesis and upregulation of Klotho and Bone Morphogenetic Protein 7, two renoprotective molecules and vascular endothelial growth factor A and its receptor. Collectively, our results suggest that injection of hUC-MSC exosomes could ameliorate I/R-AKI and accelerate renal tubular cell repair and regeneration, and that hUC-MSC exosomes may be used as a potential biological therapy for Acute kidney injury patients.

FC 132: Deficiency of Proximal Tubular Cyclin-Dependent Kinase 12 Exacerbates Kidney Injury Through DNA-Damage Response

Abstract BACKGROUND AND AIMS Acute kidney injury (AKI) is a frequent, serious condition characterized by acute tubular necrosis involving the destruction of tubular epithelial cells. Recent studies have shown that DNA damage contributes to renal tubular cell death during kidney injury. Cyclin-dependent kinase 12 (CDK12) is a member of the cyclin-dependent kinase family that phosphorylates the carboxy-terminal domain of RNA polymerase II and selectively regulates transcription of DNA-damage response (DDR) genes. CDK12 inhibitor was reported to play an important role in a variety of cancers. So far, the functions of CDK12 deficiency in the pathogenesis of AKI have not been studied. METHOD Here, we established a cisplatin-induced AKI mouse model with CDK12 knockdown mice and created stable in vitro models with CDK12 knockdown tubular epithelial cells. Cisplatin nephrotoxicity was induced by intraperitoneal injection of cisplatin (20 mg/kg). After 2 days following cisplatin treatment, blood and kidney tissues were harvested. Renal function and histology were evaluated. DDR, tubular apoptosis, cell proliferation were evaluated by immunofluorescence assays, real-time PCR, flow cytometer and western blot analysis. RESULTS Here we found that CDK12 was downregulated in the renal tubular epithelial cells of AKI patients and murine AKI models and associated with kidney functions. RNA-sequencing of kidney cortex demonstrated increased transcripts involved in DDR and tubular apoptosis signaling pathways and decreased transcripts cell proliferation pathways, in knockout versus control mice. Moreover, more severe AKI occurred in tubular cell-specific knock-down of CDK12 mice (CDK12RTEC+/–) than age- and sex-matched wild type mice, as evidenced by increased levels of serum creatinine (Scr), blood urea nitrogen (BUN) and tubular injury score. Mechanistically, CDK12 deficiency accelerated cisplatin-induced DDR, mitochondrial apoptosis and abrogates cell proliferation of renal tubular cells in these mice. Similar results were observed after the human renal tubular epithelial cell line HK-2 cells exposure to CDK12 siRNA stimulation. In contrast, lentivirus-mediated CDK12 overexpression protected against DDR and mitochondrial apoptosis while attenuating renal dysfunction, morphological damage and renal tubular cell death in cisplatin-induced AKI models. Moreover, representative Integrative Genomics Viewer (IGV) profiles demonstrated a minimal impact of gene length-dependent elongation defects, a substantial proportion of which participate in the DDR and cell proliferation. CONCLUSION Thus, proximal tubule-specific deficiency of CDK12 exacerbates acute kidney injury and tubular apoptosis, likely due to affecting the expression of genes involved in the DDR and mRNA processing.

Comparison of the treatment efficacy of umbilical mesenchymal stem cell transplantation via renal subcapsular and parenchymal routes in AKI-CKD mice

BackgroundMesenchymal stem cells (MSCs) have emerged as a promising cell-based therapy for acute kidney injury (AKI). However, the optimal route of MSC transplantation remains controversial, and there have been no comparisons of the therapeutic benefits of MSC administration through different delivery routes.MethodsIn this study, we encapsulated MSCs into a collagen matrix to help achieve local MSC retention in the kidney and assessed the survival of MSCs in vitro and in vivo. After transplanting collagen matrix-encapsulated-MSCs (Col-MSCs) under the renal capsule or into the parenchyma using the same cell dose and suspension volume in an ischemia/reperfusion injury model, we evaluated the treatment efficacy of two local transplantation routes at different stages of AKI.ResultsWe found that Col-MSCs could be retained in the kidney for at least 14 days. Both local MSC therapies could reduce tubular injury, promote the proliferation of renal tubular epithelial cells on Day 3 and alleviate renal fibrosis on Day 14 and 28. MSC transplantation via the subcapsular route exerts better therapeutic effects for renal functional and structural recovery after AKI than MSC administration via the parenchymal route.ConclusionsSubcapsular MSC transplantation may be an ideal route of MSC delivery for AKI treatment, and collagen I can provide a superior microenvironment for cell–cell and cell–matrix interactions to stabilize the retention rate of MSCs in the kidney.

Effect of BDNF-AS/miR-145-5p axis on renal tubular epithelial cell injury induced by high glucose

To investigate the effect and possible mechanism of BDNF-AS on renal tubular epithelial cell injury induced by high glucose. Human renal tubular epithelial cells HK-2 were cultured in vitro and transfected with BDNF-AS small interfering RNA or miR-145-5p mimic, or co-transfected with BDNF-AS small interfering RNA and miR-145-5p inhibitor, respectively. The cells were then intervened with 30 mmol/L glucose for 24 hours. The expression of BDNF-AS and miR-145-5p were detected by RT-qPCR. Cell proliferation was detected by CCK-8, and apoptosis was detected by flow cytometry. The expression of Bcl-2 and Bax proteins were detected by Western blotting, and the levels of IL-1β and IL-6 in cell culture supernatant were detected by enzyme-linked immunosorbent assay. Dual luciferase reporter gene experiment was used to verify the regulatory relationship of BDNF-AS with miR-145-5p. High glucose promoted the expression of BDNF-AS in HK-2 cells (P<0.05), but inhibited that of miR-145-5p (P<0.05). Interfering with BDNF-AS or overexpression of miR-145-5p decreased the inhibition rate, apoptosis rate and expression of Bax protein, IL-1β and IL-6 of HK-2 cells induced by high glucose (P<0.05), but promoted the expression of Bcl-2 protein (P<0.05). Interfering with miR-145-5p reversed the effect of interfering with BDNF-AS on the proliferation, apoptosis rate and the expression of IL-1β and IL-6 of HK-2 cells induced by high glucose. BDNF-AS could target and down-regulate miR-145-5p. Interfering with BDNF-AS may promote the proliferation of renal tubular epithelial cells induced by high glucose and inhibit cell apoptosis and the expression of inflammatory factor by down-regulating miR-145-5p.

Icariin Attenuation of Diabetic Kidney Disease Through Inhibition of Endoplasmic Reticulum Stress via G Protein-Coupled Estrogen Receptors.

Diabetic kidney disease (DKD) is the most common complication of diabetes mellitus and has become the primary cause of End-Stage Renal Disease (ESRD) globally. Icariin (ICA), an effective component extracted from Epimedium, has antiosteoporosis effect, antitumor effects, anti-ischemia effects, and other effects. In this study, a mouse DKD model was established, and Icariin solid nanoliposomes were administered to determine whether ICA had a protective effect on the renal function of DKD mice by regulating estrogen level and endoplasmic reticulum (ER) stress pathway. The results showed that the microalbumin/creatinine in urine, serum urea nitrogen, and CHOL in ICA cultured DKD mice significantly decreased, and mice nephropathy improved significantly. rat renal tubule epithelial cells were further tested, and the rat renal tubule epithelial cells were modeled by cultured cells with high glucose. The results showed that high glucose could promote the proliferation of renal tubular epithelial cells. Simultaneously, ICA can inhibit the proliferation of renal tubular epithelial cells and induce cell apoptosis. Furthermore, the expression of ER stress-related proteins IRE1 and XBP-1S was further detected. Additionally, to ICA intervention, a GPER antagonist (G-15) was added for intervention, the inhibitory effects of IRE1 and XBP-1S were reversed, and the ER stress pathway was activated. Cell experiments showed that ICA could promote GPER expression, while inhibiting GPER expression promoted the activation of ER stress pathway, and GPER expression was negatively correlated with ER stress protein expression. Therefore, the experiment proved that in DKD tissues, a high concentration of ICA can inhibit the ER stress response by promoting the expression of GPER, reducing the proliferation of diabetic nephropathy, and increasing the rate of tissue apoptosis.

In vivo mutagenicity and tumor-promoting activity of 1,3-dichloro-2-propanol in the liver and kidneys of gpt delta rats.

1,3-Dichloro-2-propanol (1,3-DCP), a food contaminant, exerts carcinogenic effects in multiple organs, including the liver and kidneys, in rats. However, the underlying mechanisms of 1,3-DCP-induced carcinogenesis remain unclear. Here, the in vivo mutagenicity and tumor-promoting activity of 1,3-DCP in the liver and kidneys were evaluated using medium-term gpt delta rat models previously established in our laboratory (GPG and GNP models). Six-week-old male F344 gpt delta rats were treated with 0 or 50mg/kg body weight/day 1,3-DCP by gavage for 4weeks. After 2weeks of cessation, partial hepatectomy or unilateral nephrectomy was performed to collect samples for in vivo mutation assays, followed by single administration of diethylnitrosamine (DEN) for tumor initiation. One week after DEN injection, 1,3-DCP treatment was resumed, and tumor-promoting activity was evaluated in the residual liver or kidneys by histopathological analysis of preneoplastic lesions. gpt mutant frequencies increased in excised liver and kidney tissues following 1,3-DCP treatment. 1,3-DCP did not affect the development of glutathione S-transferase placental form-positive foci in residual liver tissues, but enhanced atypical tubule hyperplasia in residual kidney tissues. Detailed histopathological analyses revealed glomerular injury and increased cell proliferation of renal tubular cells in residual kidney tissues of rats treated with 1,3-DCP. These results suggested possible involvement of genotoxic mechanisms in 1,3-DCP-induced carcinogenesis in the liver and kidneys. In addition, we found that 1,3-DCP exhibited limited tumor-promoting activity in the liver, but enhanced clonal expansion in renal carcinogenesis via proliferation of renal tubular cells following glomerular injury.

Embryonic stem cell-derived extracellular vesicles promote the recovery of kidney injury

BackgroundEmbryonic stem cell-derived extracellular vesicles (ESC-EVs) possess therapeutic potential for a variety of diseases and are considered as an alternative of ES cells. Acute kidney injury (AKI) is a common acute and severe disease in clinical practice, which seriously threatens human life and health. However, the roles and mechanisms of ESC-EVs on AKI remain unclear.MethodsIn this study, we evaluated the effects of ESC-EVs on physiological repair and pathological repair using murine ischemia-reperfusion injury-induced AKI model, the potential mechanisms of which were next investigated. EVs were isolated from ESCs and EVs derived from mouse fibroblasts as therapeutic controls. We then investigated whether ESC-EVs can restore the structure and function of the damaged kidney by promoting physiological repair and inhibiting the pathological repair process after AKI in vivo and in vitro.ResultsWe found that ESC-EVs significantly promoted the recovery of the structure and function of the damaged kidney. ESC-EVs increased the proliferation of renal tubular epithelial cells, facilitated renal angiogenesis, inhibited the progression of renal fibrosis, and rescued DNA damage caused by ischemia and reperfusion after AKI. Finally, we found that ESC-EVs play a therapeutic effect by activating Sox9+ cells.ConclusionsESC-EVs significantly promote the physiological repair and inhibit the pathological repair after AKI, enabling restoration of the structure and function of the damaged kidney. This strategy might emerge as a novel therapeutic strategy for ESC clinical application.

Retraction.

Retraction: "MicroRNA-381-induced down-regulation of CXCR4 promotes the proliferation of renal tubular epithelial cells in rat models of renal ischemia reperfusion injury," by Gui-Hong Zheng, Xin Wen, Yong-Jian Wang, Xin-Rui Han, Qun Shan, Wang Li, Tian Zhao, Dong-Mei Wu, Jun Lu, Yuan-Lin Zheng, J Cell Biochem. 2018; 3149-3161: The above article, published online on 26 October 2017 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcb.26466) has been retracted by agreement between the the journal's Editor in Chief, Prof. Dr. Christian Behl, and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. A detailed investigation revealed that several image elements of the experimental data were published elsewhere in a different scientific context. Thus, the editors consider the conclusions of this article to be invalid.

Aldosterone Induces the Proliferation of Renal Tubular Epithelial Cells In Vivo but Not In Vitro.

Objective To investigate the proliferation effect of aldosterone on renal tubular epithelial cells in vivo and in vitro. Methods Thirty-two male C57BL/6J mice (20–22 g) were divided randomly into four groups: sham, unilateral nephrectomy (UN), unilateral nephrectomy plus aldosterone infusion (UA), and UA plus eplerenone (UAE). The kidneys were removed 6 weeks after treatment. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry and western blotting. Human kidney proximal tubular epithelial (HK2) and mouse distal convoluted tubule (mDCT) cell lines were stimulated by aldosterone (0, 10−9, 10−8, 10−7, and 10−6 mol/L) in vitro. Cells were collected after 3, 6, 12, 24, 36, and 48 h, and proliferation of each group detected by western blotting, flow cytometry, live imaging, and the MTT assay. In addition, mDCT cells were costimulated with a medium containing a final concentration of 161 mmol/L Na+ and different concentrations of aldosterone, and the number of cells and cellular DNA content was measured by the MTT assay and flow cytometry. Results Aldosterone could induce a significant increase in the number of PCNA-positive cells in mouse kidneys accompanied by increased deposition of collagen fibers. Eplerenone could inhibit aldosterone-induced cell proliferation and collagen deposition. HK2 cells and mDCT cells administered different concentrations, and different times of aldosterone stimulation failed to cause cell proliferation, and costimulation of aldosterone and salt did not cause proliferation changes in mDCT cells. Conclusions Aldosterone perfusion can induce proliferation of mouse kidney cells in vivo, and eplerenone can inhibit this change, but aldosterone stimulates HK2 cells and mDCT in vitro without causing their proliferation.

Palbociclib induces cell cycle arrest and senescence of human renal tubular epithelial cells in vitro

To investigate the effect of palbociclib on cell cycle progression and proliferation of human renal tubular epithelial cells. Human renal tubular epithelial cell line HK-2 was treated with 1, 5, 10, and 20 μmol/L of palbociclib, and the changes in cell proliferation and viability were examined by cell counting and CCK8 assay. EDU staining was used to assess the proliferation of HK-2 cells following palbiciclib treatment at different concentrations for 5 days. The effect of palbociclib on cell cycle distribution of HK-2 cells was evaluated using flow cytometry. SA-β-Gal staining and C12FDG senescence staining were used to detect senescence phenotypes of HK-2 cells after palbociclib treatment at different concentrations for 5 days. The relative mRNA expression levels of P16, P21, and P53 and the genes associated with senescence-related secretion phenotypes were detected by RT-PCR, and the protein expressions of P16, P21 and P53 were detected by Western blotting. Palbociclib inhibited HK-2 cell proliferation and induced cell cycle arrest in G1 phase. Compared with the control cells, HK-2 cells treated with high-dose (10 μmol/L) palbociclib exhibited significantly suppressed cell proliferation activity, and the inhibitory effect was the most obvious on day 5 (P < 0.01). Palbociclib treatment significantly reduced the number of cells in S phase (P < 0.01) and induced senescence of HK-2 cells. The results of SA-β-Gal and C12FDG senescence staining showed a significantly enhanced activity of intracellular senescence-related galactosidase in palbociclib-treated HK-2 cells, suggesting significant senescence of the cells (P < 0.01). RT-PCR and Western blotting showed that palbociclib treatment significantly increased the mRNA and protein expression levels of P16, P21, and P53 in HK-2 cells (P < 0.01); the mRNA expression levels of senescence-related secretory factors also increased significantly in HK-2 cells after palbociclib treatment (P < 0.01). Palbociclib induces HK-2 cell senescence by causing cell growth arrest and delaying cell cycle progression.