CD206+CD68+ mono-macrophages and serum soluble CD206 level are increased in antineutrophil cytoplasmic antibodies associated glomerulonephritis.

BACKGROUND: Antineutrophil Cytoplasmic Antibodies (ANCA) associated glomerulonephritis (AGN) is a group of autoimmune diseases and mono-macrophages are involved in its glomerular injuries. In this study, we aim to investigate the role of CD206+ mono-macrophages in AGN. METHODS: 27 AGN patients (14 active AGN, 13 remissive AGN) together with healthy controls (n = 9), disease controls (n = 6) and kidney function adjusted controls (n = 9) from Department of Nephrology, Ruijin hospital were recruited. Flow cytometry was used to study proportion of CD206+ cells in peripheral blood. Immunohistochemistry for CD206 staining was performed and CD206 expression was scored in different kidney regions. Serum soluble CD206 (sCD206) was measured by enzyme-linked immunosorbent assay (ELISA). We also generated murine myeloperoxidase (MPO) (muMPO) ANCA by immunizing Mpo-/- mice. Mouse bone marrow-derived macrophages (BMDMs) from wild C57BL/6 mice and peripheral blood mononuclear cell (PBMC) derived macrophages from healthy donors were treated with MPO ANCA with or without its inhibitor AZD5904 to investigate the effects of MPO-ANCA on CD206 expression. RESULTS: The proportion of peripheral CD206+CD68+ cells in active AGN patients were significantly higher than that in remissive patients (p < 0.001), healthy controls (p < 0.001) and kidney function adjusted controls (p < 0.001). Serum sCD206 level in active AGN patients was higher than that in healthy controls (p < 0.05) and remissive patients (p < 0.01). Immunohistochemistry showed CD206 was highly expressed in different kidney regions including fibrinoid necrosis or crescent formation, glomeruli, periglomerular and tubulointerstitial compartment in active AGN patients in comparison with disease controls. Further studies showed MPO ANCA could induce CD206 expression in BMDMs and PBMC derived macrophages and such effects could be reversed by its inhibitor AZD5904. CONCLUSION: ANCA could induce CD206 expression on mono-macrophages and CD206+ mono-macrophages are activated in AGN. CD206 might be involved in the pathogenesis of AAV and may be a potential target for the disease.

Evaluating renal outcome of ANCA-associated renal vasculitis: comparative study of two histopathological scoring systems.

OBJECTIVES: Renal risk score (RRS) and chronicity score (CS) are both newly proposed tools to predict end stage renal disease (ESRD) which could be applicable in antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis patients. Their predictive value has not been fully studied and compared. METHODS: 252 patients with newly biopsy-proven ANCA-associated renal vasculitis were retrospectively studied at the Department of Nephrology, Ruijin Hospital, China. Patients were evaluated with RRS and CS for clinical factors, pathological lesions and outcome. Their predictive value of renal survival was also compared. RESULTS: The median RRS score point at diagnosis was 6 (interquartile range [IQR] 0-9) and CS score point was 4 (IQR 3-7). In accordance with severity of RRS category and CS grade, percentage of hypertensive patients, dialysis dependency, and level of proteinuria increased accordingly. Significant differences were found regarding dialysis dependency within RRS and CS groups (p<0.001 and p<0.01 respectively). The addition of RRS or CS scoring scheme to the base model of dialysis dependency significantly improved discrimination. The C statistic, integrated discrimination improvement and net reclassification improvement were significantly increased by adding either RRS/CS or both. Furthermore, RRS had better ROC. CONCLUSIONS: Among ANCA associated renal vasculitis patients, RRS and CS achieved similar discrimination, but the discrimination of RRS was superior.

Serum pre-albumin is prognostic for all-cause mortality in patients with community-acquired and post-operative acute kidney injury.

BACKGROUND: Acute kidney injury (AKI) is a critical clinical syndrome characterised by a rapid decrease in renal filtration, with the accumulation of products of metabolism such as creatinine and urea. In recent years, the incidence of AKI has increased not only in critically ill hospitalised patients but also in community patients. Also, the prognosis of AKI is poor and treatment is limited in these populations. The increasing incidence and poor prognosis may be the reasons why more investigators are involved in epidemiological and risk factor analysis of AKI. AIMS: To investigate the effects of these risk factors on outcomes in both community-acquired and hospitalised AKI populations to provide certain guidance for clinics and to explore the prognostic value of prealbumin on all-cause mortality in patients with community-acquired and post-operative AKI. METHODS: From 2000 to 2010, 477 patients diagnosed with AKI and treated in the Department of Nephrology, Ruijin Hospital, Shanghai Jiaotong University, were enrolled in the community-acquired AKI (CA-AKI) group and 138 patients diagnosed with AKI after an operation were enrolled in the post-operative AKI (PO-AKI) group. Data were collected at AKI onset and 1 year after discharge and analysed retrospectively. RESULTS: Compared with PO-AKI patients, more patients in CA-AKI group had chronic kidney disease, obesity and hyperlipidaemia, and fewer patients had cerebrovascular disease (CVD), anaemia, shock or arrhythmia. Risks for CA-AKI were atherosclerosis, CVD, arrhythmia, multiple organ dysfunction syndrome and usage of vasoactive agents, and risks for PO-AKI were elderly, arrhythmia and requirement of renal replacement therapy. A higher level of serum PA was associated with a better outcome in the CA-AKI group (hazard ratio 0.92, 95% confidence interval 0.85-0.996) and PO-AKI group (hazard ratio 0.91, 95% confidence interval 0.84-0.99). In the CA-AKI group, the cumulative survival rate of patients with a normal PA level (PA >20 mg/dL) was higher than that among patients with a lower PA (PA ≤20 mg/dL; 95.4% vs 88.3%, P = 0.031). Similarly, in the PO-AKI group, a normal PA level was associated with a higher survival rate (74.1% vs 47.6%, P = 0.019). CONCLUSION: Serum PA may serve as a prognostic marker for CA-AKI and PO-AKI, and further research is warranted to confirm this finding.

Identification of nestin as a urinary biomarker for acute kidney injury.

OBJECTIVES: Acute kidney injury (AKI) is a common complication in hospitalized patients and the incidence of AKI is rapidly increasing. Despite the advances in treatment of AKI, many patients still progress to end-stage renal disease and depend on dialysis. Therefore, early diagnosis and adequate treatment of AKI could improve prognosis. METHODS: We established rat models of AKI induced by cisplatin nephrotoxicity and renal ischemia-reperfusion (I/R). Urine samples were collected, labeled with isobaric tags for relative and absolute quantification agents, and then subjected to nano-LC-MS/MS-based proteomic analysis. Results of the proteomic study were confirmed by Western blot. We also performed RNAi to silence nestin and investigate its role in renal I/R injury. We then validated its clinical application by studying urine nestin levels in AKI patients with cardiovascular surgeries. RESULTS: Our proteomic analysis showed that fetuin-A, nestin, hamartin and T-kininogen were differentially expressed in the urine samples of rats after cisplatin or I/R treatment. Western blot confirmed the differential expression of these proteins in animal models and ELISA confirmed the differential expression of nestin in human urine samples. To explore the expression of nestin in the development of AKI, our results showed that nestin was primarily detected in the glomeruli and barely detected in tubular cells but increased in tubular cells during I/R- and cisplatin-induced AKI. The urine nestin-to-creatinine ratio increased earlier than serum creatinine in AKI patients with postcardiovascular surgeries. The role of nestin in AKI might be related to the p53 signaling pathway. CONCLUSIONS: Thus, our results demonstrated that urinary nestin could be a urinary biomarker for patients with AKI and its role in AKI might be related to the p53 signaling pathway.

Clinical analysis of ANCA-associated renal vasculitis patients with chronic dialysis.

OBJECTIVE: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) constitute a subgroup of life-threatening diseases which affects the kidney in more than half of the patients at diagnosis. Currently, little has been published focusing on AAV patients with dialysis. We analysed AAV patients with chronic dialysis to provide more detailed information. METHODS: From 1997 to 2011, AAV patients complicated by renal involvement resulting in end-stage renal disease (ESRD) and had undergone haemodialysis (HD) or peritoneal dialysis (PD) for at least 3 months in Shanghai Ruijin hospital were retrospectively analysed in this study. Their data were also compared to those without dialysis at the same time. RESULTS: We enrolled 49 AAV patients with chronic dialysis. 41 required dialysis at initial presentation and rest 8 progressed to ESRD during follow-up. 19 HD patients died and 6 PD patients died during follow-up, and infection was the most common cause among the patients. There was no significant difference regarding survival between HD patients and PD patients (p>0.05). However anaemia and level of triglyceride was more significantly improved in HD patients at the end of observation (p<0.05, p<0.05 respectively). Compared with patients without dialysis dependency, dialysis patients presented higher percentage of hypertension (p<0.01), more severe renal involvement and higher BVAS (p<0.01). For the outcome, survival was significantly higher in non-dialysis patients (p<0.05). CONCLUSIONS: Patients with AAV experienced a high rate of renal failure and dialysis dependence. Our study suggests that haemodialysis and peritoneal dialysis are two comparable dialysis modalities for AAV patients with ESRD. However, AAV patients with dialysis dependency had worse outcome in comparison with those without dialysis.

Application of RIFLE criteria in Chinese patients with ANCA-associated renal vasculitis.

OBJECTIVES: Antineutrophil cytoplasmic autoantibody (ANCA) associated small vessel vasculitis (AASV) constitutes a group of life-threatening diseases and renal involvement is its most severe and common manifestation. Acute kidney injury (AKI) is common in patients with AASV but the value of RIFLE criteria is still unclear in those patients. METHODS: We performed a retrospective study on patients with AASV in Shanghai Ruijin Hospital from 1997 to 2008. RESULTS: A total of 147 ANCA-associated renal vasculitis patients were studied and 92 developed AKI at diagnosis. According to RIFLE classification, 8 (8/147, 5.44%) patients had AKI-R, 15 (15/147, 10.20%) had AKI-I and 69 (69/147, 46.94%) had AKI-F. Our results demonstrated that more hypertensive patients and higher BVAS were found in patients with AKI-F than those in other groups (p<0.01 and p<0.01, respectively). Survival rate was significantly lower among patients with advanced RIFLE categories during remission-induction therapy (p<0.05). Survival rate of 1 year and total survival rate were significantly lower among patients with advanced RIFLE categories (p<0.01, p=0.001, respectively). Cox regression analysis demonstrated that advanced RIFLE categories were associated with a worse prognosis of the patients (OR=1.706, 95%CI: 1.262-2.307, p<0.01). The area under the ROC curve for mortality was 0.718 (95% CI: 0.63-0.81, p<0.001). CONCLUSIONS: The RILFE criteria is a valid measurement of both prognosis and progression in patients with AASV.

Analyzing Chinese patients with post-operative acute kidney injury.

BACKGROUND: To investigate clinical characteristics and risk factors of Chinese patients with post-operative acute kidney injury (PO-AKI). METHODS: Patients with PO-AKI in Ruijin Hospital from December 1997 to December 2005 were retrospectively studied. RESULTS: Patients' mean age was 62.2 ± 18.1 years. There were 111 males and 57 females. The mean serum creatinine at diagnosis was 370.41 ± 320.92 µmol/L and the mean estimated glomerular filtration rate was 33.56 ± 24.24 mL/min. For the outcome of the patients, 38 died and the mortality rate was 22.6%. There were 17 patients (10.1%) with Acute Dialysis Quality Initiative-RIFLE (risk-injury-failure-loss-end classification) phase R, 21 (12.5%) with phase I, and 130 (77.4%) with phase F. There was no significant difference in mortality regarding patients who underwent different types of surgeries. For the risk factors related to PO-AKI, acute tubular necrosis (ATN) increased relative risk of mortality PO-AKI (odds ratio = 7.089, 95% confidence interval = 2.069-24.288, p < 0.001). Multivariate regression models showed that ATN had a positive correlation with mortality of PO-AKI. CONCLUSIONS: PO-AKI is one of the most common causes of AKI in patients who underwent operations. Special attention should be paid to risk factors related to PO-AKI in order to improve prognosis.

Psychological Profiles of Chinese Patients With Hemodialysis During the Panic of Coronavirus Disease 2019.

Background: Hemodialysis patients not only suffer from somatic disorders but are also at high risks of psychiatric problems. Early this year, the outbreak of coronavirus disease 2019 (COVID-19) has caused great panic and anxiety worldwide. The impact of this acute public health event on the psychological status of hemodialysis patients and its relationship with their quality of life have not been fully investigated. Methods: This study comprised two parts. The initial study enrolled maintenance hemodialysis patients treated in Ruijin Hospital for more than 3 months from March to May 2020 during the ongoing COVID-19 pandemic. Patients completed three questionnaires including the Impact of Events Scale-Revised (IES-R), General Health Questionnaire-28 (GHQ-28), and Kidney Disease Quality of Life (KDQOL) Short Form (SF). Follow-up study was performed from December 2020 to January 2021, when the pandemic of COVID-19 has been effectively contained in China. Only patients enrolled in the initial study were approached to participate in the follow-up study. Results: There were 273 maintenance dialysis patients enrolled in the initial study and 247 finished the follow-up study. For the initial study, the estimated prevalence of nonspecific psychiatric morbidity was 45.8% (125/273) by GHQ-28. By IES-R, 53/273 (19.4%) patients presented with total scores above 24 that reflected clinical concerns. We found a significant difference regarding KDQOL scores between patients with different stress response (IES-R) groups (p = 0.026). Our follow-up study showed that KDQOL and SF-36 scores were significantly improved in comparison with those in the initial study (p = 0.006 and p = 0.031, respectively). Though total scores of GHQ-28 and IES-R did not change significantly, some subscales improved with statistical significance. Furthermore, gender, education background, and duration of hemodialysis were three factors that may affect patients' mental health, quality of life, or health status while dialysis duration was the only variable that correlated with those parameters. However, these correlations were combined effects of the COVID-19 pandemic and the dialysis itself. Conclusions: We found a correlation between changes in the mental health status of dialysis patients and changes in their quality of life. These responses were also mediated by patients' psychosocial parameters. Our results urge the necessity of psychotherapeutic interventions for some patients during this event.

Phosphoproteomic study of human tubular epithelial cell in response to transforming growth factor-beta-1-induced epithelial-to-mesenchymal transition.

BACKGROUND: Transforming growth factor-beta (TGF-beta)-induced epithelial-to-mesenchymal transition (EMT) plays an important role in renal fibrosis and progression of chronic kidney disease (CKD). Phosphorylation of proteins is essential to TGF-beta signaling. We applied isobaric tags for relative and absolute quantification (iTRAQ) technology to profile the phosphoproteins in tubular epithelial cells in response to TGF-beta-induced EMT in order to further study molecular events. METHODS: HK-2 cells were treated with TGF-beta1 to induce EMT. The cells were divided into a control group (without TGF-beta1 treatment) and a TGF-beta1-treated group. Phosphoproteins from two groups were extracted and differentially labeled with iTRAQ reagents and processed by 2D-nano-HPLC-MS/MS. Validating of iTRAQ analysis was performed by western blot. Bioinformatic analysis was performed by on-line databases. RESULTS: By iTRAQ-2D-nano-HPLC-MS/MS, 38 differentially expressed phosphoproteins were identified which included 19 up-regulated phosphoproteins and 19 down-regulated phosphoproteins. Western blot confirmed up-regulation of phosphorylated moesin and HSP90alpha. Bioinformatic analysis suggested that the majority of proteins were located in the nucleus and endoplasmic reticulum lumen. The phosphoproteins were categorized into 17 molecular function classifications. Nucleic acid binding protein, cytoskeletal protein and chaperone were the major categories of molecular function. A biological network was built to analyze interaction between up-regulated proteins. CONCLUSION: We demonstrate a TGF-beta1-mediated post-transcriptional regulation of EMT in tubular epithelial cells. Phosphorylation of moesin and HSP90alpha might play a role in TGF-beta-induced EMT.

Clinicopathological characteristics and outcome of Chinese patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome: a 9-year retrospective study.

BACKGROUND: The pathogenesis of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is unclear and the prognosis is poor. Few studies have been published focusing on Chinese patients with TTP-HUS. We performed a retrospective study on the clinical characteristics and outcome of Chinese patients with TTP-HUS. METHOD: Patients with TTP-HUS, admitted to our hospital from 1998 to 2006, were retrospectively analyzed. RESULTS: There were 26 females and 6 males in our study. Fifteen patients had systemic lupus erythematosus (SLE)-associated TTP-HUS; 2 had pregnancy-associated TTP-HUS; 1 had antiphospholipid syndrome-associated TTP-HUS; 2 had drug-associated TTP-HUS; 4 had malignant angionephrosclerosis- associated TTP-HUS; 3 had vasculitis-associated TTP-HUS, and the remaining 5 had idiopathic TTP-HUS. Twenty-six patients had acute kidney injury and 21 had nephrotic syndrome. Hypertension was found in 31 patients. For the treatment, 15 patients had plasmapheresis, 12 had continuous veno-venous hemodiafiltration and 14 had hemodialysis. Eighteen patients were treated with intravenous immunoglobulin. Corticosteroids were used in patients with idiopathic TTP-HUS. For the patients with SLE-associated TTP-HUS, corticosteroids and immunosuppressant were used. Outcome was poor: 6 patients died; 17 recovered from renal insufficiency; 5 progressed to chronic renal failure, and 4 were dependent on hemodialysis. CONCLUSIONS: Most of our patients had secondary TTP-HUS. SLE-associated TTP-HUS is the most common form of TTP-HUS. Early diagnosis and treatment can improve prognosis. An immunosuppressant together with corticosteroids could improve prognosis in some patients.

Analyzing fatal cases of Chinese patients with primary antineutrophil cytoplasmic antibodies-associated renal vasculitis: a 10-year retrospective study.

BACKGROUND/AIMS: Primary antineutrophil cytoplasmic antibodies (ANCA)-associated systemic vasculitis (AASV) used to have poor prognosis, and renal involvement is its most common manifestation. Few studies have been published focusing on AASV patients with poor prognosis. METHODS: From 1997 to 2006, 101 patients with ANCA-associated renal vasculitis (70 microscopic polyangiitis, MPA; 14 Wegener's granulomatosis, WG; 3 Churg-Strauss syndrome, CSS; 14 renal limited vasculitis, RLV) were diagnosed in Shanghai Ruijin Hospital and 26 deaths were recorded among them. Patients' data were retrospectively analyzed. RESULTS: Patients with WG, MPA and RLV made up for 23.1% (6/26), 65.4% (17/26) and 11.5% (3/26) of all deaths. No deaths were observed among CSS patients. Infection alone accounted for 13 deaths. Infection together with pulmonary involvement of active vasculitis accounted for 3. Organ-specific involvement of active vasculitis alone caused 8 deaths. Others died of acute myocardial infarction or gastric carcinoma. Compared with patients who survived, nonsurvivors had more severe renal insufficiency and older age (p < 0.01). There was no significant difference regarding clinical presentation at diagnosis and cause of death between patients who survived first remission-induction treatment and those who did not. Infection remained the major cause of death. CONCLUSION: Infection is the major cause of death in patients with ANCA-associated renal vasculitis, and treatment response might not correlate to severity of disease in patients with poor prognosis. Rational use of immunosuppressants could improve the prognosis.

Antineutrophil cytoplasmic antibodies-associated glomerulonephritis: From bench to bedside.

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a group of autoimmune disorders that predominantly affects small vessels. The onset of the disease is closely associated with ANCA. Renal involvement, also known as ANCA-associated glomerulonephritis (AGN), is one of the most common manifestations of AAV. In this mini-review, we described the clinical and pathological features of AGN. We then focused on recent studies on the mechanism of acute kidney lesions, including fibrinoid necrosis and crescent formation. Following the basic aspects of kidney injury in AGN, we demonstrated the clinical importance of kidney injury in determining the outcome of patients with AGN. The prognostic value of the 2010 Histopathological Classification of AGN and validating studies were summarized. Finally, treatment and novel therapeutic strategies were introduced addressing the importance of optimizing management of this patient population.

MicroRNA-30c-5p ameliorates hypoxia-reoxygenation-induced tubular epithelial cell injury via HIF1α stabilization by targeting SOCS3.

The cellular hypoxia-reoxygenation (H/R) model is an ideal method to study ischemia-reperfusion injury, which is associated with high mortality. The role of microRNA-30c-5p (miR-30c-5p) in the H/R epithelial cell model remains unknown. In the current study, we observed a significant reduction in apoptosis when miR-30c-5p was up-regulated. We also found decreased levels of C-caspase-3 (C-CASP3) and Bcl-2-associated X (BAX) proteins and increased levels of B-cell lymphoma-2 (BCL2). Epidermal growth factor receptor (EGFR) showed similar results. Down-regulating miR-30c-5p increased the levels of apoptosis and C-CASP3 and BAX expression; additionally, cell proliferation was inhibited. Hypoxia-inducible factor 1α (HIF1α) protein expression levels were up-regulated in response to up-regulation of miR-30c-5p expression. The anti-apoptotic and proliferative effects of miR-30c-5p decreased significantly after the HIF1α protein levels were knocked down. Using a luciferase reporter assay, we confirmed that miR-30c-5p targets suppressor of cytokine signaling-3 (SOCS3). HIF1α levels increased when SOCS3 was blocked. Our data show that SOCS3 expression enhances apoptosis in the H/R model. In conclusion, up-regulating miR-30c-5p protects cells from H/R -induced apoptosis and induces cell proliferation; furthermore, HIF1α markedly contributes to this protective effect. MiR-30c-5p stabilizes HIF1α expression by targeting SOCS3 to achieve anti-apoptotic and proliferative effects.

Histopathological Classification and Renal Outcome in Patients with Antineutrophil Cytoplasmic Antibodies-associated Renal Vasculitis: A Study of 186 Patients and Metaanalysis.

OBJECTIVE: Renal vasculitis is one of the most common manifestations of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) and renal histology is a key predictor of the outcome. A new histopathologic classification was proposed and validated, but the results are still debated. METHODS: We performed a retrospective analysis to validate the histopathologic classification and performed a metaanalysis to evaluate its predictive value. There were 186 patients with ANCA-associated renal vasculitis diagnosed at Ruijin Hospital who were enrolled in the retrospective study. The metaanalysis considered the data for 1601 patients. RESULTS: In our retrospective study, patients with focal class had the best renal outcome while patients with mixed class had the worst (p < 0.001). Metaanalysis showed that patients with focal class had better renal outcome than did those with crescentic class [risk ratio (RR) 0.23, 95% CI 0.16-0.34, p < 0.00001], with no evidence of heterogeneity (I2 = 0%, p = 0.96). Patients with crescentic class had better renal outcome than did those with sclerotic class (RR 0.52, 95% CI 0.41-0.64, p < 0.00001), with no evidence of heterogeneity (I2 = 2%, p = 0.43). We did not find statistical significance regarding renal outcome between mixed and crescentic classes (RR 1.14, 95% CI 0.91-1.43, p = 0.27), with no evidence of heterogeneity (I2 = 23%, p = 0.19). The retrospective study showed that lung and upper respiratory tract involvement were the most common extrarenal manifestations. CONCLUSION: We demonstrated the clinical utility of histopathologic classification in determining renal outcome in patients with AAV. Metaanalysis showed that patients with focal class had the best outcome while sclerotic class had the worst.

Urinary MicroRNA-30c-5p and MicroRNA-192-5p as potential biomarkers of ischemia-reperfusion-induced kidney injury.

Early detection of acute kidney injury is difficult due to lack of known biomarkers; previous studies have tried to identify new biomarkers for detecting acute kidney injury at an early stage. MicroRNA, a 21-23 nucleotide noncoding RNA molecule, has emerged as a desirable marker in the diagnosis and prognosis of various diseases. This study aims to identify the expression profile of microRNA in ischemia-reperfusion-induced kidney injury and determine the possibility of using the candidate microRNA as biomarker for the detection of I/R-induced kidney injury. Based on the established rat model of I/R-induced kidney injury, a microarray analysis of rat urine was performed at the beginning of operation (0 h) as well as 72 h post operation. To validate the results, urine samples from 71 patients who underwent cardiac surgery were collected, after which urinalysis was conducted to determine the microRNA concentration. An alternative expression profile of microRNAs was detected in rat urine. The quantitative validation of microRNA showed that the expression of miR-30c-5p, miR-192-5p, and miR-378a-3p was elevated significantly in urine post operation, which was consistent with those of the microarray analysis and earlier than kidney injury molecule-1 (KIM-1). In patients with acute kidney injury, increased levels of miR-30c-5p and miR-192-5p were also detected 2 h post operation, and miR-30c-5p showed preferable diagnostic value compared with protein-based biomarkers. In conclusion, an aberrant expression profile of microRNA was detected in rat urine based on the established ischemia-reperfusion animal model. Both miR-30c-5p and miR-192-5p served as important potential diagnostic markers for I/R-induced kidney injury. Impact statement Firstly, one differentiating factor in our study is that the candidate miRNAs were screened in a controlled animal model rather than in patients with acute kidney injury (AKI) to ensure the purity of the cause of disease and to avoid possible effects of comorbidities on the spectrum of urine miRNA. This ensured the presence of only the relevant candidate miRNA (that associated with I/R injury); and what's more, the alterative expression of miR-192-5p and miR-30c-5p in animal model, patients with AKI, and cell model was confirmed simultaneously, which is likely to be more convincing. Secondly, the candidate miRNAs were screened sequentially at regular time points, which covered the initiation, progression, and partial repair stages, thus ensuring that no significant miRNAs were omitted in the screening process, and miR-biomarkers in 2 h post operation showed preferable diagnostic performance.

Inhibitor of DNA Binding 1 Is Induced during Kidney Ischemia-Reperfusion and Is Critical for the Induction of Hypoxia-Inducible Factor-1α.

In this study, rat models of acute kidney injury (AKI) induced by renal ischemia-reperfusion (I/R) and HK-2 cell models of hypoxia-reoxygenation (H/R) were established to investigate the expression of inhibitor of DNA binding 1 (ID1) in AKI, and the regulation relationship between ID1 and hypoxia-inducible factor 1 alpha (HIF-1α). Through western blot, quantitative real-time PCR, immunohistochemistry, and other experiment methods, the induction of ID1 after renal I/R in vivo was observed, which was expressed mainly in renal tubular epithelial cells (TECs). ID1 expression was upregulated in in vitro H/R models at both the protein and mRNA levels. Via RNAi, it was found that ID1 induction was inhibited with silencing of HIF-1α. Moreover, the suppression of ID1 mRNA expression could lead to decreased expression and transcription of HIF-1α during hypoxia and reoxygenation. In addition, it was demonstrated that both ID1 and HIF-1α can regulate the transcription of twist. This study demonstrated that ID1 is induced in renal TECs during I/R and can regulate the transcription and expression of HIF-1α.

Role of moesin in renal fibrosis.

BACKGROUND: Renal fibrosis is the final common pathway of chronic kidney disease (CKD). Moesin is a member of Ezrin/Radixin/Moesin (ERM) protein family but its role in renal fibrosis is not clear. METHOD: Human proximal tubular cells (HK-2) were stimulated with or without TGF-ß1. Moesin and downstream target genes were examined by real-time PCR and western blot. Phosphorylation of moesin and related signaling pathway was investigated as well. Rat model of unilateral ureteral obstruction (UUO) was established and renal moesin was examined by immunohistochemistry. Moesin in HK-2 cells were knocked down by siRNA and change of downstream genes in transfected HK-2 cells was studied. All animal experiments were reviewed and approved by the Ethics Committee for animal care of Ruijin Hospital. RESULT: HK-2 cells stimulated with TGF-ß1 showed up-regulated level of α-SMA and down-regulated level of E-Cadherin as well as elevated mRNA and protein level of moesin. In rat model of UUO, renal moesin expression increased in accordance with severity of tubulointerestital fibrosis in the kidneys with ureteral ligation while the contralateral kidneys were normal. Further study showed that TGF-ß1 could induce phosphorylation of moesin which depended on Erk signaling pathway and Erk inhibitor PD98059 could block moesin phosphorylation. Effects of TGF-ß1 on moesin phosphorylation was prior to its activation to total moesin. RNA silencing studies showed that knocking down of moesin could attenuate decrease of E-Cadherin induced by TGF-ß1. CONCLUSION: We find that moesin might be involved in renal fibrosis and its effects could be related to interacting with E-Cadherin.

Pathogenesis of rapidly progressive glomerulonephritis: what do we learn?

Rapidly progressive glomerulonephritis (RPGN) is a life-threatening disease with a poor prognosis. In this review, the pathogenesis of RPGN owing to antineutrophil cytoplasmic antibody-associated crescentic glomerulonephritis and anti-GBM diseases is discussed. By the model of nephrotoxic nephritis, T cells, dendritic cells and toll-like receptors are involved in podocyte activation and parietal epithelial cell proliferation which contribute to the crescent formation and glomerular injury. Furthermore, growth factors and Goodpasture autoantigen are also involved in the onset of the disease. In the study of ANCA-associated glomerulonephritis, the role of lysosome-associated membrane protein (LAMP)-2 and neutrophil extracellular traps is well studied. However, the role of LAMP-2 in the disease pathogenesis remains uncertain. We hope this review can help us to further understand the pathogenesis of the disease.

Propylthiouracil-induced antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis versus primary ANCA-associated renal vasculitis: a comparative study.

OBJECTIVE: Renal involvement is frequently present in primary antineutrophil cytoplasmic antibody-associated small-vessel vasculitis (AAV) as well as propylthiouracil (PTU)-induced AAV. We analyzed the characteristics of patients with PTU-induced AAV with renal involvement and investigated the differences of the 2 diseases. METHODS: Thirty-six patients with PTU-induced AAV, diagnosed from 1997 to 2010, were enrolled for study. Their data were compared with those of 174 patients with primary AAV diagnosed at the same time. Renal involvement was present in all patients. RESULTS: There was a prominent proportion of young women with PTU-induced AAV (p < 0.01). They had lower levels of proteinuria and serum creatinine and higher estimated glomerular filtration rate (p < 0.01, p < 0.01, and p < 0.01, respectively). Clinical immunological abnormalities were less severe in patients with PTU-induced AAV. Patients with PTU-induced AAV had less organ involvement and lower Birmingham Vasculitis Assessment Score than patients with primary AAV (p < 0.01). Renal biopsies showed a lower proportion of glomeruli with crescents (p < 0.01). Interstitial inflammation was less severe in patients with PTU-induced AAV (p < 0.05). Similarly, interstitial fibrosis and tubular atrophy were less severe in patients with PTU-induced AAV (p < 0.01, p < 0.05, respectively). Renal survival and total survival were better in patients with PTU-associated vasculitis (p < 0.05, p = 0.01). CONCLUSION: Clinical and histopathological abnormalities were less severe in patients with PTU-induced AAV and most of them had a good prognosis.

Propylthiouracil-associated antineutrophil cytoplasmic autoantibody-positive vasculitis: retrospective study of 19 cases.

OBJECTIVE: To investigate the features, followup data, and outcomes of patients with propylthiouracil (PTU)-associated antineutrophil cytoplasmic autoantibody (ANCA)-positive vasculitis. METHODS: Nineteen patients with PTU-associated ANCA-positive vasculitis diagnosed in our hospital from 2000 to 2006 were analyzed retrospectively. RESULTS: Our data showed a female predominance among the patients. Eleven patients had involvement of more than one organ. Renal involvement was the most common manifestation. Fourteen patients underwent renal biopsy. Four patients had focal proliferative glomerulonephritis with crescent formation. Two had necrotizing glomerulonephritis with crescent formation. Two patients had minor glomerular abnormalities, 2 had IgA nephropathy, one had membranous nephropathy, one had focal proliferative glomerulonephritis, one had granulomatous interstitial nephritis, and the remaining one had focal segmental glomerular sclerosis. Immune complex glomerulonephritis was found in 3 patients. On indirect immunofluorescence, 17 patients were perinuclear-pattern ANCA-positive, one was positive for atypical ANCA, and one was positive for cytoplasmic-pattern-ANCA. By ELISA, 4 patients were positive for both myeloperoxidase (MPO)-ANCA and proteinase-3 (PR3)-ANCA, one was positive for PR3-ANCA only, and the others were positive for MPO-ANCA only. For the treatment of vasculitis, 5 patients received prednisone alone, 10 received prednisone and cyclophosphamide, and the remaining 4 did not receive prednisone or cyclophosphamide. During followup, 15 patients achieved remission, 3 patients died, and one patient depended on dialysis. In general, MPO-ANCA concentration did not correlate with disease progression, and a delayed decrease of MPO-ANCA concentration was found in most patients who achieved remission. CONCLUSION: Most patients with PTU-associated ANCA-positive vasculitis had good outcomes; however, severe cases existed. We suggest early recognition and adequate treatment are necessary to improve outcome.