p38 Signaling Mediates Naringin-Induced Osteogenic Differentiation of Porcine Metanephric Mesenchymal Cells.

OBJECTIVE: To explore the potential of metanephric mesenchymal cells (MMCs) for osteogenesis and naringin's ability to enhance this process and its molecular mechanism. METHODS: Porcine MMCs at 70 days of gestation were used as tool cells, cultured in osteogenic induction medium, identified by immunocytochemistry staining. Osteogenic potential of porcine MMCs and naringin's ability to enhance this process was tested by detecting changes in cell viability, alkaline phosphatase (ALP) activity, the expression of runt-related transcription factor 2 (Runx2), osteopontin (OPN) and osteocalcin (OCN), and the formation of mineralized nodules, and the application of the p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin. RESULTS: Immunocytochemical staining showed that the cells were Vimentin and Six2(+), E-cadherin and CK-18(-). Naringin can activate the p38 signaling pathway to enhance the osteogenesis of porcine MMCs by increasing cell viability, ALP activity, the expressions of Runx2, OPN and OCN, and the formation of mineralized nodules (P<0.05). The application of p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin, manifested by decreased ALP activity, the expressions of Runx2, OPN and OCN, and the formation of mineralized nodules (P<0.05). CONCLUSION: Naringin, the active ingredient of Chinese herbal medicine Rhizoma Drynariae for nourishing Shen (Kidney) and strengthening bone, enhances the osteogenic differentiation of renal MMCs through the p38 signaling pathway.

Genetic Diagnosis and Treatment of Inherited Renal Tubular Acidosis.

Background: Renal tubular acidosis (RTA) is caused by various disruptions to the secretion of H+ by distal renal tubules and/or dysfunctional reabsorption of HCO3- by proximal renal tubules, which causes renal acidification dysfunction, ultimately leading to a clinical syndrome characterized by hyperchloremic metabolic acidosis with a normal anion gap. With the development of molecular genetics and gene sequencing technology, inherited RTA has also attracted attention, and an increasing number of RTA-related pathogenic genes have been discovered and reported. Summary: This paper focuses on the latest progress in the research of inherited RTA and systematically reviews the pathogenic genes, protein functions, clinical manifestations, internal relationship between genotypes and clinical phenotypes, diagnostic clues, differential diagnosis, and treatment strategies associated with inherited RTA. This paper aims to deepen the understanding of inherited RTA and reduce the missed diagnosis and misdiagnosis of RTA. Key Messages: This review systematically summarizes the pathogenic genes, pathophysiological mechanisms, differential diagnosis, and treatment of different types of inherited RTA, which has good clinical value for guiding the diagnosis and treatment of inherited RTA.

The evolution of the initial manifestations and renal involvement of chinese patients with classical and late-onset Fabry disease at different sexes and ages.

BACKGROUND: Fabry disease is a rare hereditary disease involving multiple organs, and there are few reports on how the initial manifestations and renal involvement of these patients with classical and late-onset phenotype evolve with sexes and ages. To improve clinicians' understanding of Fabry disease and avoid misdiagnoses by discussing the initial manifestations, first medical specialties visited and renal involvement development in patients. METHODS: This study collected relevant data from 311 Chinese Fabry disease patients (200 males, 111 females) and descriptive statistical analysis was used to analyze the evolution of the initial manifestations and renal involvement of patients with classical and late-onset phenotype at different sexes and ages. RESULTS: Regarding the age at manifestation onset, age at the first medical specialty visited and age at the diagnosis of Fabry disease, males were earlier than females, and males with classical phenotype were earlier than males with late-onset and females with classical phenotype. In both male and female patients, the initial manifestations of classical patients were mainly acroparesthesia, and the first medical specialty visited were mainly pediatrics and neurology. The initial manifestations of late-onset patients were mainly renal and cardiovascular involvement, and the first medical specialty visited were mainly nephrology and cardiology. In classical patients, both male and female, the initial manifestations of the preschool and the juvenile groups were mainly acroparesthesia, and the frequency of renal and cardiovascular involvement in the young group was higher than that in the preschool and juvenile groups. There was no obvious renal involvement in the preschool group, renal involvement was most common in the young group and the middle-aged and elderly group. Proteinuria can appear in classical male patients as early as approximately 20 years, and renal insufficiency can occur at approximately 25 years. With age, over 50% of classical male patients can develop varying degrees of proteinuria at the age of 25 and renal insufficiency at the age of 40. 15.94% of the patients progressed to dialysis or kidney transplantation, mainly classical males. CONCLUSIONS: The initial manifestation of Fabry disease is affected by sex, age and classical/late-onset phenotype. The initial manifestations were mainly acroparesthesia and the frequency and degree of renal involvement increased gradually with aging in classical male patients.

Genetic diagnosis and treatment of hereditary renal tubular disease with hypokalemia and alkalosis.

Renal tubules play an important role in maintaining water, electrolyte, and acid-base balance. Renal tubule dysfunction can cause electrolyte disorders and acid-base imbalance. Clinically, hypokalemic renal tubular disease is the most common tubule disorder. With the development of molecular genetics and gene sequencing technology, hereditary renal tubular diseases have attracted attention, and an increasing number of pathogenic genes related to renal tubular diseases have been discovered and reported. Inherited renal tubular diseases mainly occur due to mutations in genes encoding various specific transporters or ion channels expressed on the tubular epithelial membrane, leading to dysfunctional renal tubular reabsorption, secretion, and excretion. An in-depth understanding of the molecular genetic basis of hereditary renal tubular disease will help to understand the physiological function of renal tubules, the mechanism by which the kidney maintains water, electrolyte, and acid-base balance, and the relationship between the kidney and other systems in the body. Meanwhile, understanding these diseases also improves our understanding of the pathogenesis of hypokalemia, alkalosis and other related diseases and ultimately promotes accurate diagnostics and effective disease treatment. The present review summarizes the most common hereditary renal tubular diseases (Bartter syndrome, Gitelman syndrome, EAST syndrome and Liddle syndrome) characterized by hypokalemia and alkalosis. Further detailed explanations are provided for pathogenic genes and functional proteins, clinical manifestations, intrinsic relationship between genotype and clinical phenotype, diagnostic clues, differential diagnosis, and treatment strategies for these diseases.

Diagnosis and genotype-phenotype correlation in patients with PKD1/TSC2 contiguous gene deletion syndrome.

Deletions involving the TSC2 and PKD1 genes lead to tuberous sclerosis complex (TSC) and autosomal dominant polycystic kidney disease (ADPKD), which is known as TSC2-PKD1 contiguous gene deletion syndrome (PKDTS). PKDTS leads to severe symptoms and death. There are few reported cases of PKDTS, the phenotypic descriptions are poor, and detailed statistics and descriptions of the time of onset and prognosis of PKDTS are lacking. This is the first study to report on the clinical data of PKDTS patients in China. We analyzed all cases including Chinese individuals and summarized the clinical manifestations and genetic characteristics. Our study was the first to use a combination of exome sequencing and multiplex ligation-dependent probe amplification (MLPA) to screen and diagnose PKDTS. We found that many PKDTS patients have the following: multiple renal cysts; angiofibromas (≥ 3) or fibrous cephalic plaque; subependymal nodules; seizures; intellectual disability. PKDTS develops into polycystic kidney disease from before birth to 17 years old and the time of occurrence of end-stage renal disease or dialysis was 21.62 ± 12.87 years of age, which was significantly earlier than in ADPKD caused by PKD1 mutation. Compared with non-Chinese individuals of diverse ancestry, Chinese people have significant differences in the clinical characteristics, including ungual fibromas (≥ 2), and shagreen patch. Five novel large deletions were identified in Chinese. We found no relationship between the clinical phenotype and the genotype. We combined exome sequencing with MLPA to develop a diagnostic method for PKDTS.

Novel method for the genomic analysis of PKD1 mutation in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease. Although next-generation sequencing (NGS) technology can be used to sequence tens of thousands of DNA molecules simultaneously. It has poor capture efficiency for the six PKD1 pseudogenes and GC-rich regions. Multiplex ligation-dependent probe amplification (MLPA) technology can detect consecutive deletions of exons, but it is less sensitive for single-base mutations. However, pathogenic genes might not be detected in some patients, even when using the above methods. Improving the detection rate of pathogenic genes is an important technical problem hindering clinical diagnosis of ADPKD. Four pedigrees of ADPKD patients with mutation sites not identified by NGS were examined by other methods. First, MLPA was performed. Then, pedigrees in which MLPA did not identify pathogenic genes were subjected to multiplex polymerase chain reaction (MPCR) and targeted region sequencing. Finally, the detected mutation sites were verified by Sanger sequencing. The results showed that MLPA detected the following PKD1 exonic deletion mutations in three pedigrees: PKD1-18 nt-290 nt, PKD1-up-257 nt, PKD1-up-444 nt and PKD1-3 nt-141 nt. A new mutation site was identified through targeted region sequencing in one pedigree: PKD1 NM_001009944: c.151T > C at the protein level, described as p. Cys51Arg. In summary, we established a system of genetic detection and analytical methods, from NGS to MLPA to targeted region sequencing and finally to Sanger sequencing. We combined MPCR and targeted region sequencing for the first time in ADPKD diagnosis, which further improved diagnosis accuracy. Moreover, we identified one new missense mutation and four new deletion mutations.

Effectiveness of Chinese herbal medicine combined with Western medicine on deferring dialysis initiation for nondialysis chronic kidney disease stage 5 patients: a multicenter prospective nonrandomized controlled study.

BACKGROUND: In clinical practice, Chinese herbal medicine (CHM) purportedly has beneficial therapeutic effects for chronic kidney disease (CKD), which include delaying disease progression and dialysis initiation. However, there is a lack of high-quality evidence-based results to support this. Therefore, this study aimed to evaluate the efficacy of CHM combined with Western medicine in the treatment of stage 5 CKD. METHODS: This was a prospective nonrandomized controlled study. Stage 5 CKD (nondialysis) patients were recruited form 29 AAA class hospitals across China from July 2014 to April 2019. According to doctors' advice and the patients' wishes, patients were assigned to the CHM group (Western medicine + CHM) and the non-CHM group (Western medicine). Patient demographic data, primary disease, blood pressure, Chinese and Western medical drugs, clinical test results, and time of dialysis initiation were collected during follow-up. RESULTS: A total of 908 patients were recruited in this study, and 814 patients were finally included for further analysis, including 747 patients in the CHM group and 67 patients in the non-CHM group. 482 patients in the CHM group and 52 patients in the non-CHM group initiated dialysis. The median time of initiating dialysis was 9 (7.90, 10.10) and 3 (0.98,5.02) months in the CHM group and non-CHM group, respectively. The multivariate Cox regression analysis showed that patients in the CHM group had a significantly lower risk of dialysis [adjusted hazard ratio (aHR): 0.38; 95% confidence interval (CI): 0.28, 0.53] compared to those in the non-CHM group. After 1:2 matching, the outcomes of 160 patients were analyzed. The multivariate Cox regression analysis showed that patients in the CHM group had a significantly lower risk of dialysis (aHR: 0.32; 95% CI: 0.21, 0.48) compared to patients in the non-CHM group. Also, the Kaplan-Meier analysis demonstrated that the cumulative incidence of dialysis in the CHM group was significantly lower than that in the non-CHM group (log-rank test, P<0.001) before and after matching. CONCLUSIONS: This study suggest that the combination of CHM and Western medicine could effectively reduce the incidence of dialysis and delay the time of dialysis initiation in stage 5 CKD patients.

ROBO2-mediated RALDH2 signaling is required for common nephric duct fusion with primitive bladder.

Congenital anomalies of the urinary tract are a significant cause of morbidity in infancy, and many congenital anomalies are linked to ureter development; however, the mechanism by which congenital anomalies control ureter development remains unknown. The loss of Robo2 can cause ureter defects and vesicoureteral reflux. However, how Robo2 impacts ureter development is unclear. We found that ROBO2 is expressed in the common nephric duct (CND) and primitive bladder, and impacts CND migration and fusion with the primitive bladder via its novel binding partner retinaldehyde dehydrogenase-2 (RALDH2). Delayed apoptosis that is due to the failure of CND fusion with the primitive bladder in the Robo2-/-embryo results in an abnormal ureter connection to the CND, which is required for ureter development. We define a novel pathway in which the CND is remodeled by ROBO2 and retinoic acid rescued the ureter anomalies in the Robo2-/-embryo. These findings may be relevant to diverse disease conditions that are associated with altered signaling in the primitive bladder.

Disruption of Robo2-Baiap2 integrated signaling drives cystic disease.

Hereditary renal cystic diseases are characterized by defects in primary cilia of renal tubular epithelial cells and abnormality of tubular epithelium, which ultimately result in the development of renal cysts. However, the mechanism leading from abnormality of the tubular epithelium to cystogenesis is not well understood. In this report, we demonstrate a critical role for Robo2 in regulating epithelial development, including ciliogenesis, polarization, and differentiation. We found that Robo2 deficiency results in cystic kidneys, and the cyst cells showed defective cilia and polarity defects in tubular epithelium. The cyst cells, less than terminally differentiated, continue to proliferate. We further established that Robo2 works with p53 as well as polarity and ciliary proteins (Par3, PKCς, ZO-2, and Claudin-2) to regulate these processes. Robo2 binds to Baiap2 (also known as IRSp53) through the IRSp53/MIM homology domain in renal epithelial cells. This binding allows Robo2 to phosphorylate MDM2 at Ser166 via Baiap2 and maintain p53 homeostasis. Disruption of the Robo2-Baiap2 complex causes MDM2 to be subjected to dephosphorylation, leading to a high level of active p53, and initiated p53-mediated cellular senescence via p21 and decreased the expression of ZO-1, ZO-2, PKCς, Par3, and Claudin-2 proteins, resulting in defects in epithelial development, including ciliogenesis, polarization, and differentiation. Importantly, double knockout of Robo2 and p53 rescued all the epithelial defects in kidneys compared with those in Robo2-knockout kidneys. Taken together, the present results demonstrate that Robo2 deficiency causes renal cystic disease, which is largely dependent on defective Robo2-Baiap2 integrated signaling in kidneys.

Predictive Capabilities of Three Widely Used Pathology Classification Systems and a Simplified Classification (Beijing Classification) in Primary IgA Nephropathy.

BACKGROUND/AIMS: Several pathological classification systems were commonly used in clinical practice to predict the prognosis of IgA nephropathy (IgAN). However, how prognostic value differs between these systems is unclear. The aim of this study was to compare the Lee grade, the Oxford classification, and the Haas classification and to find a simplified classification. METHODS: We retrospectively analyzed IgAN cases diagnosed between January 2002 and December 2007. The endpoints were progression to end-stage renal disease (ESRD) or a ≥50% decline in estimated glomerular filtration rate (eGFR). The predictive capabilities were evaluated by comparing the ability of discrimination (continuous net reclassification) and calibration (Akaike information criterion [AIC]). RESULTS: A total of 412 IgAN patients were included in the study. The average follow-up period was 80.62 ± 23.63 months. A total of 44 (10.68%) patients progressed to ESRD, and 70 (16.99%) patients showed a ≥50% decline in eGFR. All multivariate Cox regression models had limited power for high AIC values. The prognostic values of the Lee grade and the Oxford classification were higher than those of models containing only established baseline clinical indicators for progression to ESRD or a ≥50% decline in eGFR (Lee grade 0.50, 95% CI 0.21-0.74; Oxford classification 0.48, 95% CI 0.28-0.71). The prognostic value of the Haas classification was lower than that of the other pathological classification systems for progression to ESRD or a ≥50% decline in eGFR (Lee grade 0.53, 95% CI 0.23-0.92; Oxford classification 0.59, 95% CI 0.10-0.74). The prognostic value of hierarchical classification (Beijing classification) using M and T lesion was similar to the Oxford classification. CONCLUSIONS: Both the Lee grade and the Oxford classification showed incremental prognostic values beyond established baseline clinical indicators. The Haas classification was slightly inferior to the Lee grade and the Oxford classification. The hierarchical classification (Beijing classification) using less pathological parameters does not lose predictive efficiency.

Identifying gene mutations of Chinese patients with polycystic kidney disease through targeted next-generation sequencing technology.

BACKGROUND: Polycystic kidney disease (PKD) is the most common hereditary kidney disease. The main mutational genes causing autosomal dominant polycystic kidney disease (ADPKD) are PKD1 and PKD2 as well as some rare pathogenic genes. Unilateral PKD is rare in clinics, and its association with gene mutations is unclear. METHODS: Targeted next-generation sequencing (NGS) was performed to detect the renal ciliopathy-associated genes (targeted NGS panel including 63 genes) in PKD patients. RESULTS: Forty-eight PKD1 and PKD2 mutation sites were detected in 44 bilateral PKD patients, of which 48 were PKD1 mutation sites (87.5%) and six were PKD2 mutation sites (12.5%). All of which exhibited typical ADPKD. Furthermore, we detected HNF1B heterozygous mutations in three families. Although these three patients showed HNF1B heterozygous mutations, their clinical characteristics differed and showed phenotypic heterogeneity. CONCLUSIONS: Targeted NGS panel was helpful in detecting typical ADPKD patients and even in non-typical PKD patients. Macromutation in HNF1B may lead to bilateral PKD. The 16 novel PKD gene mutation sites and two novel PKD2 gene mutation sites discovered in this study have some significance in genetic counseling for ADPKD patients, and increase the number of studied families and expand the mutation database of ADPKD.

Metanephric mesenchyme-derived Foxd1+ mesangial precursor cells alleviate mesangial proliferative glomerulonephritis.

Mesangial proliferative glomerulonephritis (MsPGN) is a glomerular disease characterized by the proliferation of mesangial cells and the accumulation of mesangial matrix. No effective treatment is currently able to stop or reverse the disease process. Here, we isolated metanephric mesenchyme-derived Foxd1+ mesangial precursor cells from E13.5 Foxd1Cre; DTRflox double transgenic embryo mice. The Foxd1+ cells showed the cell-specific expression of high levels of Foxd1 without Six2 and manifested specific cell surface markers of mesenchymal stem cells while retaining their differentiation potential. Next, an anti-Thy1 MsPGN rat model was established, and the Foxd1+ cells were injected into the tail veins 24 h later. We found that the Foxd1+ cells could improve the pathological changes to the kidney and significantly reduce proteinuria by inhibiting the sonic hedgehog pathway. Moreover, the Foxd1+ cells could inhibit PDGF-BB-induced activation of mesangial cells by secreting multiple cytokines, including hepatocyte growth factor. Our study uncovered the novel function of Foxd1+ mesangial precursor cells in repairing the damaged mesangium, stabilizing the structure and function of mesangial cells, and restoring their therapeutic effect on the MsPGN. KEY MESSAGES: It is viable to isolate highly purified metanephric mesenchyme-derived Foxd1+ mesangial precursor cells using transgenic mice. Foxd1+ cells could alleviate experimental mesangial proliferative glomerulonephritis and PDGF-induced mesangial cell proliferation through a variety of mechanisms including inhibiting the sonic hedgehog pathway and secreting multiple cytokines. As the progenitor cells of mesangial cells, Foxd1+ cells could stabilize the structure and function of mesangial cells that had undergone pathological changes.

The role of transcriptional factor D-site-binding protein in circadian CCL2 gene expression in anti-Thy1 nephritis.

Mesangial proliferative glomerulonephritis (MsPGN) is an inflammatory disease, but both the nature of disease progression and its regulation remain unclear. In the present study, we monitored the course of anti-Thy1 nephritis from days 1 to 5 and established gene expression profiles at each time point using microarrays to explore the development of inflammation. According to the gene expression profiles, macrophage infiltration (triggered by CCL2 activation) was evident on day 1 and enhanced inflammation over the next few days. We screened for genes with expression levels similar to CCL2 and found that the upregulation of the circadian gene albumin D-site-binding protein (DBP) was involved in CCL2 activation in mesangial cells. More importantly, CCL2 expression showed oscillatory changes similar to DBP, and DBP induced peak CCL2 expression at 16:00 a clock on day 1 in the anti-Thy1 nephritis model. We knocked down DBP through transfection with a small interfering RNA (siRNA) and used RNA sequencing to identify the DBP-regulated TNF-α-CCL2 pathway. We performed chromatin immunoprecipitation sequencing (ChIP-Seq) and the dual luciferase assay to show that DBP bound to the TRIM55 promoter, regulating gene expression and in turn controlling the TNF-α-CCL2 pathway. In conclusion, DBP-regulated circadian CCL2 expression by the TRIM55-TNF pathway in injured mesangial cells at an early stage, which promoted macrophage recruitment and in turn triggered infiltration and inflammation in a model of anti-Thy1 nephritis.

Effects of Cyclosporine A on the Development of Metanephros in the Pregnant BALB/c Mice.

BACKGROUND:: Cyclosporine A (CsA) is a commonly used clinical immunosuppressant. However, CsA exposure in rabbits during the gestation period was shown to cause a postnatal decrease in the number of nephrons, with the effects remaining unknown. In this study, we aimed to explore the effects of CsA on metanephros development in the pregnant BALB/c mice. METHODS:: Pregnant mice were randomly divided into two groups, and CsA (10 mg·kg-1·d-1) was subcutaneously injected from gestation day 10.5 to day 16.5 in the CsA group, whereas a comparable volume of normal saline was given to the control group. All of the mice were sacrificed on gestation day 17.5 and serum CsA concentration was measured. The fetuses were removed and weighed, and their kidneys were prepared for histological assessment and polymerase chain reaction assay. In an in vitro experiment, embryo kidneys of fetal mice on gestation day 12.5 were used, and CsA (10 µmol/L) was added in the culture of the CsA group. The growth pattern of the ureteric bud and nephrons was assessed by lectin staining. RESULTS:: No significant differences in the weight of embryo (4.54 ± 1.22 vs. 3.26 ± 1.09 mg) were observed between the CsA and control groups, the thickness of the cortical (510.0 ± 30.3 vs. 350.0 ± 29.7 µm, P < 0.05) and nephrogenic zone (272.5 ± 17.2 vs. 173.3 ± 24.0 µm, P < 0.05), and the number of glomeruli (36.5 ± 0.7 vs. 27.5 ± 2.1, P < 0.05) were reduced in the CsA group when compared to the control group. The cell proliferation of Ki-67 positive index between control and CsA group (307.0 ± 20.0 vs. 219.0 ± 25.0, P < 0.05) in the nephrogenic zone was decreased with the increase of apoptotic cells (17.0 ± 2.0 vs. 159.0 ± 33.0, P < 0.05). The mRNA expression of WT-1, Pax2, and Pax8 was downregulated by CsA treatment. As for the in vitro CsA group, the branch number of the ureteric bud was decreased in the CsA-treated group with the nephrons missing in contrast to control after the incubation for 24 h and 72 h (all P < 0.0001). CONCLUSION:: Treatment of CsA suppressed metanephros development in the pregnant mice; however, the potential action of mechanism needs to be further investigated.

ERK1/2 signaling mediated naringin-induced osteogenic differentiation of immortalized human periodontal ligament stem cells.

Periodontal ligament stem cells (PDLSCs) are promising tools for the investigations of cell differentiation and bone regeneration. However, the limited life span significantly restricts their usefulness. In this study, we established an immortalized PDLSC cell line by the introduction of Bmi1 (PDLSC-Bmi1). Several genes related to cell cycle, cell replication and stemness were found to be changed with the overexpression of Bmi1. Compared with primary PDLSCs, the immortalized cells had a slower aging rate, maintained in a proliferative state without crisis for more than 30 passages, and retained the molecular markers and biological functions of primary ones. Using the PDLSC-Bmi1, we confirmed the promotive effect of naringin on osteogenesis. Naringin promoted the osteogenic differentiation of PDLSC-Bmi1 manifested as the increased activity of alkaline phosphatase (ALP), expression of the runt-related transcription factor 2 (Runx2) and osteocalcin (OCN), and formation of mineralized nodules. In addition, the extracellular regulated protein kinases (ERK) 1/2 was found to be activated by naringin, and the ERK1/2 specific inhibitor significantly inhibited naringin-induced osteogenic differentiation in PDLSC-Bmi1. Our results indicated that the overexpression of Bmi1 extended the life span of PDLSCs without perturbing their biological functions, and that naringin promoted the osteogenesis of PDLSC-Bmi1 at least partially through the ERK1/2 signaling pathway.

System analysis of gene mutations and clinical phenotype in Chinese patients with autosomal-dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disorder mainly caused by mutation in PKD1/PKD2. However, ethnic differences in mutations, the association between mutation genotype/clinical phenotype, and the clinical applicable value of mutation detection are poorly understood. We made systematically analysis of Chinese ADPKD patients based on a next-generation sequencing platform. Among 148 ADPKD patients enrolled, 108 mutations were detected in 127 patients (85.8%). Compared with mutations in Caucasian published previously, the PKD2 mutation detection rate was lower, and patients carrying the PKD2 mutation invariably carried the PKD1 mutation. The definite pathogenic mutation detection rate was lower, whereas the multiple mutations detection rate was higher in Chinese patients. Then, we correlated PKD1/PKD2 mutation data and clinical data: patients with mutation exhibited a more severe phenotype; patients with >1 mutations exhibited a more severe phenotype; patients with pathogenic mutations exhibited a more severe phenotype. Thus, the PKD1/PKD2 mutation status differed by ethnicity, and the PKD1/PKD2 genotype may affect the clinical phenotype of ADPKD. Furthermore, it makes sense to detect PKD1/PKD2 mutation status for early diagnosis and prognosis, perhaps as early as the embryo/zygote stage, to facilitate early clinical intervention and family planning.

Efficacy of Leflunomide, Telmisartan, and Clopidogrel for Immunoglobulin A Nephropathy: A Randomized Controlled Trial.

BACKGROUND: The efficacy and safety of telmisartan combined with clopidogrel, leflunomide, or both drugs for immunoglobulin A nephropathy (IgAN) are unclear. This study was designed to evaluate the efficacy and safety of telmisartan combined with clopidogrel, leflunomide, or both drugs for IgAN. METHODS: It is a multicenter, prospective, double-dummy randomized controlled trial. Primary IgAN patients were recruited in 13 renal units across Beijing, China, from July 2010 to June 2012. After a 4-week telmisartan (80 mg/d) wash-in, 400 patients continuing on 80 mg/d telmisartan were randomly assigned to additionally receive placebo (Group A), 50 mg/d clopidogrel (Group B), 20 mg/d leflunomide (Group C), or 50 mg/d clopidogrel and 20 mg/d leflunomide (Group D). The 24-week intervention was completed by 360 patients. The primary endpoint was change in 24-h proteinuria at 24 weeks. A linear mixed-effect model was used to analyze the changes at 4, 12, and 24 weeks. Generalized estimating equations were used to evaluate changes in hematuria grade. This trial was registered at the Chinese Clinical Trial Registry. RESULTS: The effects of telmisartan combined with leflunomide on changes in proteinuria (0.36 [95% confidence interval (CI) 0.18-0.55] g/d, P < 0.001), in serum uric acid (76.96 [95% CI 57.44-96.49] µmol/L, P < 0.001), in serum creatinine (9.49 [95% CI 6.54-12.44] µmol/L, P < 0.001), and in estimated glomerular filtration rate (-6.72 [95% CI-9.46 to -3.98] ml·min-1·1.73 m-2, P < 0.001) were statistically significant, whereas they were not statistically significant on changes in systolic and diastolic blood pressure and weight (P > 0.05). Telmisartan combined with clopidogrel had no statistical effect on any outcome, and there was no interaction between the interventions. No obvious adverse reactions were observed. CONCLUSIONS: Telmisartan combined with leflunomide, not clopidogrel, is safe and effective for decreasing proteinuria in certain IgAN patients. TRIAL REGISTRATION: chictr.org.cn, ChiCTR-TRC-10000776; http://www.chictr.org.cn/showproj.aspx?proj=8760.

A porcine model of relief of unilateral ureteral obstruction: study on self-repairing capability over multiple time points.

It is still controversial whether renal tubular interstitial fibrosis (TIF) is a reversible process. Although previous studies examining TIF have been carried out in rodents, their kidney size and physiological character differ with humans, and the difference among diverse individuals before and after damage was obvious. Thus an experimental animal model to simulate human kidney disease was urged to be established. In order to clarify whether TIF is reversible, and the exact time points that the kidney has the capacity to be repaired, a porcine relief of unilateral ureteral obstruction (R-UUO) model was developed. Kidney damage and reparation were observed dynamically in vivo over various time points. Pigs were randomized divided into three groups (n = 6): UUO 5 days group, UUO 7 days, and UUO 10 days group. Each porcine in that groups underwent UUO and subsequent R-UUO for three time points. Renal function, histological structure, and protein expressions of α-smooth muscle actin (α-SMA), vimentin and E-cadherin were evaluated at different time points. Following R-UUO after 5 and 7 days of UUO, compared to UUO, serum creatinine levels were significantly decreased. Renal pathological tissue damage was repaired. The expressions of α-SMA and vimentin were decreased and E-cadherin expression was increased (P < 0.05). However, during R-UUO 14, 28, and 56 days after 10 days of UUO, serum creatinine was not decreased significantly. The expressions of α-SMA and vimentin consistently remained at high levels. Renal damage was unable to be restored and resulted in chronic lesions. Kidney damage induced by UUO can be reversed in early stages. However, longer time of UUO with significant levels of TIF showed limited reversibility. The porcine R-UUO model provides an ideal animal model for the investigation of kidney injury and repair as well as for the evaluation of the effect of drug treatment.

Myofibrillogenesis Regulator 1 Rescues Renal Ischemia/Reperfusion Injury by Recruitment of PI3K-Dependent P-AKT to Mitochondria.

To investigate whether myofibrillogenesis regulator 1 (MR-1) attenuates renal ischemia/reperfusion (I/R) injury via inhibiting phosphorylated Akt (p-Akt) mitochondrial translocation-mediated opening of the mitochondrial permeability transition pore (mPTP), we injected adenovirus containing MR-1 gene or its siRNAs to the left kidney subcapsular areas of Sprague-Dawley rats, which subsequently underwent experimental renal I/R injury. Renal functions and the severity of the tubular injury were evaluated by the serum creatinine and blood urea nitrogen levels and the pathological scores. We also examined the mitochondrial morphology and functions. Total/p-Akt were assessed by western blot using the mitochondrial and the cytosolic fractions of cortex of renal tissue, respectively. We found that mitochondrial and cytosolic MR-1 levels and mitochondrial p-Akt decreased, and cytosolic p-Akt increased after reperfusion. Subcapsular injection of adenovirus led to higher MR-1 expression in the mitochondria/cytosol, inhibited mPTP opening, and alleviated renal I/R injury; adenovirus injection also upregulated mitochondrial total and p-Akt levels more prominently compared with the normal saline (NS) group. Subcapsular injection of MR-1 siRNAs significantly lowered MR-1 expression and induced renal injury, with increased mPTP opening and mitochondrial damage, similar to I/R injury. MR-1 interacted with Akt in renal cortex homogenate. Wortmannin, a phosphatidylinositol 3 kinase (PI3K) inhibitor, abolished both mitochondrial p-Akt recruitment and the protective effect of MR-1 overexpression on I/R injury. To conclude, MR-1 protects kidney against I/R injury through inhibiting mPTP opening and maintaining mitochondrial integrity, through the recruitment of PI3K-dependent p-Akt to the mitochondria. MR-1 could be a new therapeutic strategy for renal I/R injury.

Roles of the kidney in the formation, remodeling and repair of bone.

The relationship between the kidney and bone is highly complex, and the kidney plays an important role in the regulation of bone development and metabolism. The kidney is the major organ involved in the regulation of calcium and phosphate homeostasis, which is essential for bone mineralization and development. Many substances synthesized by the kidney, such as 1,25(OH)2D3, Klotho, bone morphogenetic protein-7, and erythropoietin, are involved in different stages of bone formation, remodeling and repair. In addition, some cytokines which can be affected by the kidney, such as osteoprotegerin, sclerostin, fibroblast growth factor -23 and parathyroid hormone, also play important roles in bone metabolism. In this paper, we summarize the possible effects of these kidney-related cytokines on bone and their possible mechanisms. Most of these cytokines can interact with one another, constituting an intricate network between the kidney and bone. Therefore, kidney diseases should be considered among patients presenting with osteodystrophy and disturbances in bone and mineral metabolism, and treatment for renal dysfunction may accelerate their recovery.