The GDF11 expression pattern and its effect on organ regeneration after acute injury in the elderly population are highly controversial topics. In our study, GDF11/8 expression increased after kidney ischemia-reperfusion injury (IRI), and the relatively lower level of GDF11/8 in the kidneys of aged mice was associated with a loss of proliferative capacity and a decline in renal repair, compared to young mice. In vivo, GDF11 supplementation in aged mice increased vimentin and Pax2 expression in the kidneys as well as the percentage of 5-ethynyl-2'-deoxyuridine (EdU)-positive proximal tubular epithelial cells. GDF11 improved the renal repair, recovery of renal function, and survival of elderly mice at 72 h after IRI. Moreover, the addition of recombinant GDF11 to primary renal epithelial cells increased proliferation, migration, and dedifferentiation by upregulating the ERK1/2 pathway in vitro. Our study indicates that GDF11/8 in the kidney decreases with age and that GDF11 can increase tubular cell dedifferentiation and proliferation as well as improve tubular regeneration after acute kidney injury (AKI) in old mice.

Transcriptome profiles established using high-throughput sequencing can be effectively used for screening genome-wide differentially expressed genes (DEGs). RNA sequences (from RNA-seq) and microRNA sequences (from miRNA-seq) from the tissues of longissimus dorsi muscle of two indigenous Chinese pig breeds (Diannan Small-ear pig [DSP] and Tibetan pig [TP]) and two introduced pig breeds (Landrace [LL] and Yorkshire [YY]) were examined using HiSeq 2000 to identify and compare the differential expression of functional genes related to muscle growth and lipid deposition. We obtained 27.18 G clean data through the RNA-seq and detected that 18,208 genes were positively expressed and 14,633 of them were co-expressed in the muscle tissues of the four samples. In all, 315 DEGs were found between the Chinese pig group and the introduced pig group, 240 of which were enriched with functional annotations from the David database and significantly enriched in 27 Gene Ontology (GO) terms that were mainly associated with muscle fiber contraction, cadmium ion binding, response to organic substance and contractile fiber part. Based on functional annotation, we identified 85 DEGs related to growth traits that were mainly involved in muscle tissue development, muscle system process, regulation of cell development, and growth factor binding, and 27 DEGs related to lipid deposition that were mainly involved in lipid metabolic process and fatty acid biosynthetic process. With miRNA-seq, we obtained 23.78 M reads and 320 positively expressed miRNAs from muscle tissues, including 271 known pig miRNAs and 49 novel miRNAs. In those 271 known miRNAs, 20 were higher and 10 lower expressed in DSP-TP than in LL-YY. The target genes of the 30 miRNAs were mainly participated in MAPK, GnRH, insulin and Calcium signaling pathway and others involved cell development, growth and proliferation, etc. Combining the DEGs and the differentially expressed (DE) miRNAs, we drafted a network of 46 genes and 18 miRNAs for regulating muscle growth and a network of 15 genes and 16 miRNAs for regulating lipid deposition. We identified that CAV2, MYOZ2, FRZB, miR-29b, miR-122, miR-145-5p and miR-let-7c, etc, were key genes or miRNAs regulating muscle growth, and FASN, SCD, ADORA1, miR-4332, miR-182, miR-92b-3p, miR-let-7a and miR-let-7e, etc, were key genes or miRNAs regulating lipid deposition. The quantitative expressions of eight DEGs and seven DE miRNAs measured with real-time PCR certified that the results of differential expression genes or miRNAs were reliable. Thus, 18,208 genes and 320 miRNAs were positively expressed in porcine longissimus dorsi muscle. We obtained 85 genes and 18 miRNAs related to muscle growth and 27 genes and 16 miRNAs related to lipid deposition, which provided new insights into molecular mechanism of the economical traits in pig.

Robo2 is the cell surface receptor for the repulsive guidance cue Slit and is involved in axon guidance and neuronal migration. Nephrin is a podocyte slit-diaphragm protein that functions in the kidney glomerular filtration barrier. Here, we report that Robo2 is expressed at the basal surface of mouse podocytes and colocalizes with nephrin. Biochemical studies indicate that Robo2 forms a complex with nephrin in the kidney through adaptor protein Nck. In contrast to the role of nephrin that promotes actin polymerization, Slit2-Robo2 signaling inhibits nephrin-induced actin polymerization. In addition, the amount of F-actin associated with nephrin is increased in Robo2 knockout mice that develop an altered podocyte foot process structure. Genetic interaction study further reveals that loss of Robo2 alleviates the abnormal podocyte structural phenotype in nephrin null mice. These results suggest that Robo2 signaling acts as a negative regulator on nephrin to influence podocyte foot process architecture.

Previous studies have indicated that Zinc ribbon domain-containing 1 (ZNRD1) is attributed to the carcinogenesis of human tumors. However, the role of ZNRD1 and its regulation in hepatocellular carcinoma (HCC) are still largely unclear. In this study, we examined the expression profiles of ZNRD1 in HCC tissues by immunohistochemistry (IHC) and publicly datasets analysis. In vitro and in vivo experiments were conducted to identify the function of ZNRD1 in HCC. In addition, miRNA potentially targeting ZNRD1 was predicted by bioinformatics analysis and further verified via in vitro experiments. Our results revealed that ZNRD1 was frequently upregulated in HCC tissues compared with that in nontumor tissues. High ZNRD1 expression in HCC tissues was positively associated with advanced tumor stage and poor prognosis. Function experiments showed that knockdown of ZNRD1 inhibited cell growth and invasion in vitro, and suppressed tumor development in vivo. Moreover, ZNRD1 promoted the activation of Wnt/β-catenin signaling pathway in HCC. Importantly, miR-26b directly inhibited the transcription activity of ZNRD1. Overexpression of ZNRD1 dramatically abolished the inhibitory effects of miR-26b on HCC cells. Taken together, our results uncover a novel mechanistic role for miR-26b/ZNRD1 axis in HCC, proposing ZNRD1 inhibition as a potent therapeutic strategy for hepatocellular carcinoma.

TSC2-PKD1 contiguous gene deletion syndrome is characterized by tuberous sclerosis complex and polycystic kidney disease. We obtained peripheral blood mononuclear cells from a patient with TSC2-PKD1 contiguous gene deletion syndrome. We performed reprogramming using non-integrative episomal vectors to obtain human induced pluripotent stem cells (iPSCs). The obtained iPSCs had a normal karyotype and expressed human ES cell-specific cell surface markers and genes; in teratomas, iPSCs differentiated into derivatives of all three germ layers. The iPSCs can be used to study pathogenesis of TSC2-PKD1 contiguous gene deletion syndrome and serve as a potential therapeutic target.

Induced pluripotent stem cell (iPSC) lines for studies investigating many diseases can be established from peripheral blood mononuclear cells; here, an iPSC line was established from CD34+ cells isolated from the peripheral blood of a healthy woman. The cells were electrotransfected with three different recombinant plasmids to generate a normal-karyotype iPSC line that expresses characteristic surface markers and other pluripotent stem cell genes and can differentiate into all three germ layers in vivo. These newly established iPSC lines, a normal human cell line, can serve as a control line in studies investigating the pathogenesis of various diseases and meet the conditions for organoid studies.

Mesothelial cell injury plays an important role in peritoneal fibrosis. Present clinical therapies aimed at alleviating peritoneal fibrosis have been largely inadequate. Mesenchymal stem cells (MSCs) are efficient for repairing injuries and reducing fibrosis. This study was designed to investigate the effects of MSCs on injured mesothelial cells and peritoneal fibrosis.

High-affinity Na(+)-dependent dicarboxylate cotransporter (NaDC3) can transport Krebs cycle intermediates into cells. Our previous study has shown that NaDC3 promotes cellular senescence, but its mechanism is not clear. It is known that when the concentration of intermediates in Krebs cycle is increased, NAD(+)/NADH ratio will be decreased. NAD(+)-dependent histone deacetylase sirtuin1 (SIRT1) prolongs mammalian cellular lifespan. Therefore, we propose that NaDC3 accelerates cellular aging by inhibiting SIRT1. After NaDC3 was overexpressed in two human embryo lung fibroblastic cell lines, WI38 and MRC-5, we found that the cells displayed aging-related phenotypes in advance. Meanwhile, the level of SIRT1 activity was down-regulated. In WI38/hNaDC3 cells treated with the activators of SIRT1, aging-related phenotypes induced by NaDC3 were obviously improved. The NAD(+)/NADH ratio in WI38/hNaDC3 cells was also decreased. Further study found that enhanced intracellular NAD(+) level could attenuate the aging phenotypes induced by NaDC3. Thus, NaDC3 promotes cellular senescence probably by inhibiting NAD(+)-dependent SIRT1.

We previously found that mesenchymal stem cells (MSCs) injected intravenously could attenuate peritoneal adhesion by secreting tumor necrosis alpha-stimulating gene (TSG)-6, while MSCs injected intraperitoneally could not. However, the underlying mechanism remains unclear. This study was designed to investigate the means by which MSCs exert their effects.

Mesangial cells play a prominent role in the development of inflammatory diseases and autoimmune disorders of the kidney. Mesangial cells perform the essential functions of helping to ensure that the glomerular structure is stable and regulating capillary flow, and activated mesangial cells acquire proinflammatory activities. We investigated whether activated mesangial cells display immune properties and control the development of T cell immunity.

Alport Syndrome (AS) is a progressive hereditary glomerular disease. It is often accompanied by sensorineural hearing loss and ocular abnormalities and can sometimes develop into end stage renal disease (ESRD), which is caused by mutations in the genes encoding the collagen type IV family of proteins.

The pathogenic mechanism of autosomal dominant polycystic kidney disease (ADPKD) is unclear. Similar to tumour cells, polycystic kidney cells are primarily dependent on aerobic glycolysis for ATP production. Compared with rodents, miniature pigs are more similar to humans. This study is the first time to investigate the effects of the combination of metformin and 2-deoxyglucose (2DG) in a pig model of chronic progressive ADPKD.

We aimed to investigate the underlying mechanism of endothelial cells (ECs) proliferation in anti-Thy-1 nephritis.

Autosomal recessive polycystic kidney disease is a hereditary fibrocystic disease that involves the kidneys and biliary tract. Its major histological presentations are the fusiform dilatation of renal collecting ducts and the malformation of the hepatobiliary ductal plate. We isolated peripheral blood mononuclear cells from a 21-year-old adult female patient carrying a homozygous p.L2665P mutation in the PKHD1 gene and used nonintegrated exogenous in vitro differentiation vectors for reprogramming to obtain human induced pluripotent stem cells. The induced pluripotent stem cells thus established had a normal karyotype, expressed markers of pluripotency, and could differentiate into three germ layers in the body.

Mesangial proliferative glomerulonephritis (MsGN) is a significant global threat to public health. Inflammation plays a crucial role in MsGN; however, the underlying mechanism remains unknown. Herein, we demonstrate that suppression of the cytokine signaling-1 (SOCS1)/signal transducer and activator of transcription 1 (STAT1) signaling pathway is associated with renal inflammation and renal injury in MsGN. Using MsGN rat (Thy1.1 GN) and mouse (Habu GN) models, renal SOCS1/STAT1 was determined to be associated with CD4+ T cell infiltration and related cytokines. In vitro, SOCS1 overexpression repressed IFN-γ-induced MHC class II and cytokine levels and STAT1 phosphorylation in mesangial cells. SOCS1 and STAT1 inhibitors significantly inhibited IFN-γ-induced CIITA promoter activity and MHC class II expression. In conclusion, our study emphasizes the pivotal role of the SOCS1/STAT1 axis in the regulation of inflammation in MsGN.

Gentamicin may cause acute kidney injury. The pathogenesis of gentamicin nephrotoxicity is unclear. Autophagy is a highly conserved physiological process involved in removing damaged or aged biological macromolecules and organelles from the cytoplasm. The role of autophagy in the pathogenesis of gentamicin nephrotoxicity is unclear. The miniature pigs are more similar to humans than are those of rodents, and thus they are more suitable as human disease models. Here we established the first gentamicin nephrotoxicity model in miniature pigs, investigated the role of autophagy in gentamicin-induced acute kidney injury, and determined the prevention potential of rapamycin against gentamicin-induced oxidative stress and renal dysfunction. At 0, 1, 3, 5, 7 and 10 days after gentamicin administration, changes in autophagy, oxidative damage, apoptosis and inflammation were assessed in the model group. Compared to the 0-day group, gentamicin administration caused marked nephrotoxicity in the 10-day group. In the kidneys of the 10-day group, the level of autophagy decreased, and oxidative damage and apoptosis were aggravated. After rapamycin intervention, autophagy activity was activated, renal damage in proximal tubules was markedly alleviated, and interstitium infiltration of inflammatory cells was decreased. These results suggest that rapamycin may ameliorate gentamicin-induced nephrotoxicity by enhancing autophagy.

Antenatal hydronephrosis and vesicoureteral reflux (VUR) are common renal tract birth defects. We recently showed that disruption of the Robo2 gene is associated with VUR in humans and antenatal hydronephrosis in knockout mice. However, the natural history, causal relationship and developmental origins of these clinical conditions remain largely unclear. Although the hydronephrosis phenotype in Robo2 knockout mice has been attributed to the coexistence of ureteral reflux and obstruction in the same mice, this hypothesis has not been tested experimentally. Here we used noninvasive high-resolution micro-ultrasonography and pathological analysis to follow the progression of antenatal hydronephrosis in individual Robo2-deficient mice from embryo to adulthood. We found that hydronephrosis progressed continuously after birth with no spontaneous resolution. With the use of a microbubble ultrasound contrast agent and ultrasound-guided percutaneous aspiration, we demonstrated that antenatal hydronephrosis in Robo2-deficient mice is caused by high-grade VUR resulting from a dilated and incompetent ureterovesical junction rather than ureteral obstruction. We further documented Robo2 expression around the developing ureterovesical junction and identified early dilatation of ureteral orifice structures as a potential fetal origin of antenatal hydronephrosis and VUR. Our results thus demonstrate that Robo2 is crucial for the formation of a normal ureteral orifice and for the maintenance of an effective anti-reflux mechanism. This study also establishes a reproducible genetic mouse model of progressive antenatal hydronephrosis and primary high-grade VUR.

The main pathological characteristic of glomerulonephritis is diffuse mesangial cell proliferation. MiR-34a is associated with the proliferation of various organs and cancer cells. However, the role of miR-34a in renal proliferation diseases is not clear. Therefore, this study aimed to elucidate the mechanism of miR-34a in the regulation of renal mesangial cell proliferation. The miR-34a expression level at different time points in an anti-Thy1 mesangial proliferative nephritis rat model was determined by qRT-PCR. The cell proliferation rate and cell cycle changes were measured in the in vitro cultured rat mesangial cells (RMCs). Our results suggested that miR-34a expression was negatively correlated with the degree of cell proliferation in the anti-Thy1 nephritis model. MiR-34a could extend the G0/G1 phase and block cell proliferation in RMCs. Dual-luciferase assay results showed that there were binding sites of miR-34a at 3'-UTR of platelet-derived growth factor receptor-β (PDGFR-β). MiR-34a can inhibit PDGFR-β protein expression at a post-transcriptional level, suppress Ras/MAPK signaling pathways, and down-regulate expression of cell cycle proteins at the G0/G1 phase, such as cyclin D1, CDK4/CDK6. In addition, miR-34a may also inhibit RMC proliferation by directly targeting cyclin E and CDK2. MiR-34a inhibits exogenous stimuli-induced proliferation of mesangial cells. Expression levels of phospho-PDGFR-β and phospho-MEK1 (an important downstream molecule in PDGFR-β-induced signaling pathway) were significantly increased in the anti-Thy-1 nephritis rat model. These results suggest that miR-34a may regulate RMC proliferation by directly inhibiting expressions of PDGFR-β, MEK1, and cell cycle proteins, cyclin E and CDK2.

Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published.

The mechanisms of kidney aging are not yet clear. Studies have shown that immunological inflammation is related to kidney aging. Toll-like receptors (TLRs) are one of the receptor types of the body's innate immune system. The function of the TLR system and the mechanisms by which it functions in renal aging remain unclear. In the present study, we, for the first time, systematically investigated the role of the TLR system and the inflammation responses activated by TLRs during kidney aging.