Integrative ATAC-seq and RNA-seq analysis associated with diabetic nephropathy and identification of novel targets for treatment by dapagliflozin

Dapagliflozin (DAPA) are clinically effective in improving diabetic nephropathy (DN). However, whether and how chromatin accessibility changed by DN responds to DAPA treatment is unclear. Therefore, we performed ATAC-seq, RNA-seq, and weighted gene correlation network analysis to identify the chromatin accessibility, the messenger RNA (mRNA) expression, and the correlation between clinical phenotypes and mRNA expression using kidney from three mouse groups: db/m mice (Controls), db/db mice (case group), and those treated with DAPA (treatment group). RNA-Seq and ATAC-seq conjoint analysis revealed many overlapping pathways and networks suggesting that the transcriptional changes of DN and DAPA intervention largely occured dependently on chromatin remodeling. Specifically, the results showed that some key signal transduction pathways, such as immune dysfunction, glucolipid metabolism, oxidative stress and xenobiotic and endobiotic metabolism, were repeatedly enriched in the analysis of the RNA-seq data alone, as well as combined analysis with ATAC-seq data. Furthermore, we identified some candidate genes (UDP glucuronosyltransferase 1 family, Dock2, Tbc1d10c, etc.) and transcriptional regulators (KLF6 and GFI1) that might be associated with DN and DAPA restoration. These reversed genes and regulators confirmed that pathways related to immune response and metabolism pathways were critically involved in DN progression.

The presence of exudative thickening of Bowman's capsule predict poor prognosis in diabetic kidney disease

BACKGROUND

The relationship between Bowman's capsule thickening and progression of diabetic kidney disease (DKD) remains uncertain.

METHODS

Renal biopsy specimens from 145 DKD patients and 20 control subjects were evaluated for Bowman's capsule thickness. Immunohistochemical staining assessed col4α2, laminin β1, and albumin expression. In a discovery cohort of 111 DKD patients with eGFR ≥ 30 ml/min/1.73 m2, thickening was classified as fibrotic or exudative. The composite endpoint included CKD stage 5, dialysis initiation, and renal disease-related death. Prognosis was analyzed using Kaplan-Meier and Cox regression analyses. Two validation cohorts were included.

RESULTS

Three types of thickening were observed: fibrotic, exudative, and periglomerular fibrosis. Parietal epithelial cell matrix protein accumulation contributed to fibrotic thickening, while albumin was present in exudative thickening. Bowman's capsule was significantly thicker in DKD patients (5.74 ± 2.09 μm) compared to controls (3.38 ± 0.43 μm, P < 0.01). In discovery cohort, the group of exudative thickning had a poorer prognosis(median time 20 months vs 57 months, P = 0.000). Cox multivariate analysis revealed that exudative thickening of Bowman's capsule were associated with a poor prognosis. The validation cohorts confirmed the result.

CONCLUSIONS

Various mechanisms contribute to Bowman's capsule thickening in DKD. The proportion of exudative thickening may serve as a valuable prognostic indicator for DKD patients.

Fractal Analysis of Left Ventricular Trabeculae in Patients with End-Stage Renal Disease: A Random Survival Tree Analysis

BACKGROUND

The complexity of left ventricular (LV) trabeculae is related to the prognosis of several cardiovascular diseases.

PURPOSE

To evaluate the prognostic value of LV trabecular complexity in patients with end-stage renal disease (ESRD).

STUDY TYPE

Prospective outcome study.

POPULATION

207 participants on maintenance dialysis, divided into development (160 patients from 2 centers) and external validation (47 patients from a third center) cohorts, and 72 healthy controls.

FIELD STRENGTH

3.0T, steady-state free precession (SSFP) and modified Look-Locker imaging sequences.

ASSESSMENT

All participants had their trabecular complexity quantified by fractal analysis using cine SSFP images. Patients were followed up every 2 weeks until April 2023, or endpoint events happened. Random Forest (RF) and Cox regression models including age, diabetes, LV mass index, mean basal fractal dimension (FD), and left atrial volume index, were developed to predict major adverse cardiac events (MACE). Patients were divided into low- and high-risk groups based on scores derived from the RF model and survival compared.

STATISTICAL TESTS

Receiver operating characteristic curve analysis; Kaplan-Meier survival analysis with log rank tests; Harrel's C-index to assess model performance. A P value <0.05 was considered statistically significant.

RESULTS

Fifty-five patients (26.57%) experienced MACE during a median follow-up time of 21.83 months. An increased mean basal FD (≥1.324) was associated with a significantly higher risk of MACE. The RF model (C-index: 0.81) had significantly better discrimination than the Cox regression model (C-index: 0.74). Participants of the external validation dataset classified into the high-risk group had a hazard of experiencing MACE increased by 12.29 times compared to those in the low-risk group.

DATA CONCLUSION

LV basal FD was an independent predictor for MACE in patients with ESRD. Reliable risk stratification models could be generated based on LV basal FD and other MRI variables using RF analysis.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Metabolic Risk Profile and Graft Function Deterioration 2 Years After Kidney Transplant

Importance

Studies exploring the association of body weight and metabolic status with graft function deterioration (GFD) after kidney transplantation have produced inconsistent findings. Few studies have examined whether metabolically healthy overweight or obesity (MHO) may contribute to GFD.

Objective

To evaluate associations of overweight or obesity and metabolic disorders with GFD in recipients of kidney transplant.

Design, Setting, and Participants

This multicenter retrospective cohort study was conducted from January 1, 2020, through June 30, 2021, with a follow-up period of 2 years after kidney transplantation. Participants included adult recipients of cadaveric kidney transplant in 4 transplantation centers in China. Participants were classified as 4 metabolic phenotypes according to their BMI and metabolic status. Data were analyzed from July to August 2023.

Exposures

Overweight and obesity were characterized by body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 24 or greater. Metabolic disorder was identified by existence of a minimum of 2 of 4 conditions: hypertension, hyperglycemia, increased triglyceride, and decreased high-density lipoprotein cholesterol.

Main Outcome and Measures

The main outcome was GFD, defined as a decrease in estimated glomerular filtration rate of at least 25% within 6 months to 2 years after transplant.

Results

A total of 1260 adult recipients of cadaveric kidney transplant (mean [SD] age, 43.97 [11.51] years; 755 [59.92%] male) were included in the study, and 127 (10.08%) participants experienced the primary outcome of GFD during follow-up. After accounting for confounding factors in multivariable analyses, overweight or obesity (odds ratio [OR], 1.64; 95% CI, 1.10-2.44; P = .02) and metabolic disorder (OR, 1.71; 95% CI, 1.12-2.63; P = .01) were associated with increased risk of GFD. The MHO subgroup exhibited a greater risk for GFD (OR, 2.37; 95% CI, 1.01-5.57; P = .048) compared with participants who did not have overweight or obesity or metabolic disorder. All components of metabolic disorder, with the exception of elevated triglyceride, were associated with GFD. There was a dose-response association of number of metabolic disorder components (OR per 1 additional condition, 1.40; 95% CI, 1.20-1.63; P < .001) and BMI (OR per 1-unit increase, 1.90; 95% CI, 1.03-1.15; P = .002) with increased risk for GFD. A nonlinear association was observed between BMI and risk of GFD.

Conclusions and Relevance

In this cohort study of recipients of cadaveric kidney transplant, individuals with overweight or obesity or metabolic disorder had a significantly higher risk of experiencing GFD. Individuals with MHO had an elevated risk for graft function deterioration. Additional studies with larger sample size and longer follow-up are necessary to validate our findings.

Shear wave elastography parameters adds prognostic value to adverse outcome in kidney transplantation recipients

INTRODUCTION

The tissue stiffness of donor kidneys in transplantation may increase due to pathological changes such as glomerulosclerosis and interstitial fibrosis, and those changes associate worse outcomes in kidney transplantation recipients. Ultrasound elastography is a noninvasive imaging examination with the ability to quantitatively reflect tissue stiffness. Aim of this study was to evaluate the prognostic value of ultrasound elastography for adverse kidney outcome in kidney transplantation recipients.

METHODS

Shear wave elastography (SWE) examinations were performed by two independent operators in kidney transplantation recipients. The primary outcome was a composite of kidney graft deterioration, all-cause re-hospitalization, and all-cause mortality. Survival analysis was calculated by Kaplan-Meier curves with the log-rank test and Cox regression analysis.

RESULTS

A total of 161 patients (mean age 46 years, 63.4% men) were followed for a median of 20.1 months. 27 patients (16.77%) reached the primary endpoint. The mean and median tissue stiffness at the medulla (hazard ratio: 1.265 and 1.229, respectively), estimated glomerular filtration rate (eGFR), and serum albumin level were associated with the primary outcome in univariate Cox regression. Adding mean or median medulla SWE to a baseline model containing eGFR and albumin significantly improved its discrimination (C-statistics: 0.736 for the baseline, 0.766 and 0.772 for the model added mean and median medulla SWE, respectively).

CONCLUSION

The medullary tissue stiffness of kidney allograft measured by shear wave elastography may provide incremental prognostic value to adverse outcomes in kidney transplantation recipients. Including SWE parameters in kidney transplantation recipients management could be considered to improve risk stratification.

Dapagliflozin alleviates renal inflammation and protects against diabetic kidney diseases, both dependent and independent of blood glucose levels

Introduction

Diabetic kidney disease (DKD) has become the leading cause of end-stage renal disease worldwide. Therefore, efforts to understand DKD pathophysiology and prevent its development at the early phase are highly warranted.

Methods

Here, we analyzed kidneys from healthy mice, diabetic mice, and diabetic mice treated with the sodium-glucose cotransporter 2 inhibitor dapagliflozin using ATAC and RNA sequencing. The findings were verified at the protein levels and in cultured cells.

Results

Our combined method of ATAC and RNA sequencing revealed Csf2rb, Btla, and Isg15 as the key candidate genes associated with hyperglycemia, azotemia, and albuminuria. Their protein levels were altered together with multiple other inflammatory cytokines in the diabetic kidney, which was alleviated by dapagliflozin treatment. Cell culture of immortalized renal tubular cells and macrophages unraveled that dapagliflozin could directly effect on these cells in vitro as an anti-inflammatory agent independent of glucose concentrations. We further proved that dapagliflozin attenuated ischemia/reperfusion-induced chronic kidney injury and renal inflammation in mice.

Discussion

Overall, our data emphasize the importance of inflammatory factors to the pathogenesis of DKD, and provide valuable mechanistic insights into the renoprotective role of dapagliflozin.

Pharmacokinetics of Henagliflozin in Dialysis Patients with Diabetes

AIM

This study aimed to assess the pharmacokinetics of henagliflozin in dialysis patients with diabetes.

METHODS

In this prospective, randomized, open-label study where 10 hemodialysis and 10 peritoneal dialysis patients with diabetes were randomized in a 1:1:1:1 ratio to oral administration of henagliflozin in doses of 5 and 10 mg/day. The pharmacokinetics of a single dose of henagliflozin on Days 1 and 2, the minimum plasma concentration (Cmin) of the steady state on Day 10, and single hemodialysis clearance of henagliflozin were measured.

RESULTS

The mean values of Cmax were 70.2-77.0 ng/mL and 105-143 ng/mL in the 5 mg and 10 mg henagliflozin groups, respectively; the mean values of AUCinf were 777-811 h*ng/mL and 1290-1730 h*ng/mL in the 5 mg and 10 mg henagliflozin groups, respectively. The median Tmax values ranged from 1 to 3 h across the dose range. The mean values of T1/2 of henagliflozin were 14.1-14.5 and 16.2-21.0 h in the 5 mg and 10 mg groups, respectively. The Cmin values of the steady state in dialysis patients taking 5 mg and 10 mg of henagliflozin were 15.0 ± 4.4 ng/mL and 26.8 ± 16.3 ng/mL, respectively, which were 123.8% and 131.0% higher than those in diabetic patients with normal renal function, respectively. Henagliflozin concentration was decreased by 1.1% after hemodialysis treatment. No treatment-related serious adverse events or discontinuations occurred.

CONCLUSIONS

Henagliflozin at the current recommended dosage may be safe, although it is possible to result in slight accumulation in patients on dialysis.

REGISTRATION

Chinese Clinical Trial Registry number ChiCTR2200062872. The date of registration: August 22, 2022.

Assessment of the Prognostic Value of MRI Left Ventricular Global Function Index (LVGFI) in Patients With End-Stage Renal Disease Under Maintenance Dialysis

BACKGROUND

Left ventricular global function index (LVGFI) integrates LV volumetric and functional parameters. In patients with end-stage renal disease (ESRD), cardiac injury manifests as LV hypertrophy and dysfunction. However, the prognostic value of LVGFI in this population remains unclear.

PURPOSE

To investigate the association of LVGFI with major adverse cardiac events (MACE) in patients with ESRD.

STUDY TYPE

Prospective.

POPULATION

One hundred fifty-eight ESRD patients (mean age: 54.1 ± 14.4 years; 105 male) on maintenance dialysis.

FILED STRENGTH/SEQUENCE

3.0 T, balanced steady-state free precession (bSSFP) cine and modified Look-Locker inversion recovery (MOLLI) sequences.

ASSESSMENT

LV volumetric and functional parameters were determined from bSSFP images. LVGFI was calculated as the ratio of stroke volume to global volume and native T1 was determined from MOLLI T1 maps. MACE was recorded on follow up. Models were developed to predict MACE from conventional risk factors combined with LVGFI, GLS, native T1, and LV mass index (LVMI), respectively. Subgroup analyses were further performed in participants with LVEF above median.

STATISTICAL TESTS

Cox proportional hazard regression and log-rank test were used to investigate the association between LVGFI and MACE. The predictive models were evaluated and compared using Harrell's C-statistics and DeLong tests. A P value <0.05 was considered statistically significant.

RESULTS

Thirty-four MACE occurred during the median follow-up period of 26 months. The hazard of MACE increased by 114% for each 10% decrease in LVGFI in univariable analysis. The predictive model consisting of LVGFI (C-statistic: 0.724) had significantly better predictive performance than the others (all P < 0.001). These results were consistent in patients (N = 79) with LVEF > median (63.54%).

DATA CONCLUSION

LVGFI is a novel marker for MACE risk stratification in patients with ESRD and was better able to predict MACE than native T1 mapping and GLS.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

P2X7R/AKT/mTOR signaling mediates high glucose-induced decrease in podocyte autophagy

Diabetic nephropathy is one of the leading causes of end-stage renal disease worldwide. In our study we found that Adenosine triphosphate (ATP) content was significantly increased in the urine of diabetic mice. We examined the expression of all purinergic receptors in the renal cortex and found that only purinergic P2X7 receptor (P2X7R) expression was significantly increased in the renal cortex of wild-type diabetic mice and that the P2X7R protein partially co-localized with podocytes. Compared with P2X7R(-/-) non-diabetic mice, P2X7R(-/-) diabetic mice showed stable expression of the podocyte marker protein podocin in the renal cortex. The renal expression of microtubule associated protein 1A/1B light chain 3 (LC-3II) in wild-type diabetic mice was significantly lower than in wild-type controls, whereas the expression of LC-3II in the kidneys of P2X7R(-/-) diabetic mice was not significantly different from that of P2X7R(-/-) non-diabetic mice. In vitro, high glucose induced an increase in p-Akt/Akt, p-mTOR/mTOR and p62 protein expression along with a decrease in LC-3II levels in podocytes, whereas after transfection with P2X7R siRNA, Phosphorylated serine/threonine kinase (p-Akt)/Akt, Phosphorylated mechanistic target of rapamycin (p-mTOR)/mTOR, and p62 expression were restored and LC-3II expression was increased. In addition, LC-3II expression was also restored after inhibition of Akt and mTOR signaling with MK2206 and rapamycin, respectively. Our results suggest that P2X7R expression is increased in podocytes in diabetes, and that P2X7R is involved in the inhibition of podocyte autophagy by high glucose, at least in part through the Akt-mTOR pathway, thereby exacerbating podocyte damage and promoting the onset of diabetic nephropathy. Targeting P2X7R may be a potential treatment for diabetic nephropathy.

Nirmatrelvir/ritonavir for patients with SARS-CoV-2 infection and impaired kidney function during the Omicron surge

Background: Nirmatrelvir/ritonavir has demonstrated effectiveness in high-risk patients with coronavirus disease 2019 (COVID-19). However, investigations on the efficacy and safety of nirmatrelvir/ritonavir in patients with kidney dysfunction are limited. Methods: Data were collected from the patients admitted to a COVID-19 referral center in Shanghai, China. Patients were at least 18 years of age and had a baseline estimated glomerular filtration rate (eGFR) of <60 ml/min/1·73 m². The primary endpoint was a composite of all-cause mortality, intensive care unit admission, or cardiovascular events. The secondary endpoint was viral shedding. Results: Among the 195 participants, 73 received nirmatrelvir/ritonavir. A lower risk of the primary endpoint was observed in nirmatrelvir/ritonavir recipients compared with non-recipients [adjusted HR 0.56 (95% CI: 0.32-0.96); p = 0.035]. Nirmatrelvir/ritonavir recipients experienced a shorter duration of viral shedding [adjusted HR 3·70 (95%CI: 2.60-5.28); p < 0.001) and faster viral load clearance versus non-recipients. Among the nirmatrelvir/ritonavir users, earlier initiation of nirmatrelvir/ritonavir within 5 days since COVID-19 diagnosis was related with shorter viral shedding time (adjusted HR 7.84 [95% CI: 3.28-18.76]; p < 0.001) compared to late initiation. No patients reported serious adverse events during treatment. Conclusion: Our findings support the early initiation of nirmatrelvir/ritonavir for high-risk patients with impaired kidney function. This could improve patient outcomes and shorten the viral shedding period.

Sodium glucose co-transporter 2 (SGLT2) inhibition via dapagliflozin improves diabetic kidney disease (DKD) over time associatied with increasing effect on the gut microbiota in db/db mice

BACKGROUND

The intestinal microbiota disorder gradually aggravates during the progression of diabetes. Dapagliflozin (DAPA) can improve diabetes and diabetic kidney disease(DKD). However, whether the gut microbiota plays a role in the protection of DAPA for DKD remains unclear.

METHODS

To investigate the effects of DAPA on DKD and gut microbiota composition during disease progression, in our study, we performed 16S rRNA gene sequencing on fecal samples from db/m mice (control group), db/db mice (DKD model group), and those treated with DAPA (treat group) at three timepoints of 14weeks\18weeks\22weeks.

RESULTS

We found that DAPA remarkably prevented weight loss and lowered fasting blood glucose in db/db mice during disease progression, eventually delaying the progression of DKD. Intriguingly, the study strongly suggested that there is gradually aggravated dysbacteriosis and increased bile acid during the development of DKD. More importantly, comparisons of relative abundance at the phylum level and partial least squares-discriminant analysis (PLS-DA) plots roughly reflected that the effect of DAPA on modulating the flora of db/db mice increased with time. Specifically, the relative abundance of the dominant Firmicutes and Bacteroidetes was not meaningfully changed among groups at 14 weeks as previous studies described. Interestingly, they were gradually altered in the treat group compared to the model group with a more protracted intervention of 18 weeks and 22 weeks. Furthermore, the decrease of Lactobacillus and the increase of norank_f:Muribaculaceae could account for the differences at the phylum level observed between the treat group and the model group at 18 weeks and 22 weeks.

CONCLUSION

We firstly found that the protective effect of DAPA on DKD may be related to the dynamic improvement of the gut microbiota over time, possibly associated with the impact of DAPA on the bile acid pool and its antioxidation effect.

Astragaloside IV Targets Macrophages to Alleviate Renal Ischemia-Reperfusion Injury via the Crosstalk between Hif-1α and NF-κB (p65)/Smad7 Pathways

(1) Background: Astragaloside IV (AS-IV) is derived from Astragalus membranous (AM), which is used to treat kidney disease. Macrophages significantly affect the whole process of renal ischemia-reperfusion (I/R). The regulation of macrophage polarization in kidneys by AS-IV was the focus. (2) Methods: Renal tubular injury and fibrosis in mice were detected by Hematoxylin and Eosin staining and Masson Trichrome Staining, separately. An ELISA and quantitative real-time polymerase chain reaction were used to explore the cytokine and mRNA expression. Western blot was used to determine protein expression and siRNA technology was used to reveal the crosstalk of signal pathways in RAW 264.7 under hypoxia. (3) Results: In the early stages of I/R injury, AS-IV reduced renal damage and macrophage infiltration. M1-associated markers were decreased, while M2 biomarkers were increased. The NF-κB (p65)/Hif-1α pathway was suppressed by AS-IV in M1. Moreover, p65 dominated the expression of Hif-1α. In the late stages of I/R injury, renal fibrosis was alleviated, and M2 infiltration also decreased after AS-IV treatment. Hif-1α expression was reduced by AS-IV, while Smad7 expression was enhanced. Hif-1α interferes with the expression of Smad7 in M2. (4) Conclusions: AS-IV promoted the differentiation of M1 to M2, relieving the proinflammatory response to alleviate the kidney injury during the early stages. AS-IV attenuated M2 macrophage infiltration to prevent kidney fibrosis during the later stages.

A novel contrast-induced acute kidney injury mouse model based on low-osmolar contrast medium

The contrast-induced acute kidney injury (CI-AKI) has been becoming the third common cause of hospital-acquired acute kidney injury. An ideal animal model is essential for understanding the pathophysiology of CI-AKI. Previous CI-AKI studies were mostly performed on rats with high-osmolar contrast medium (HOCM), which is unsuitable for transgenic researches. This study provides a novel, efficient and reproducible CI-AKI model which was developed in mouse by administrating a low-osmolar contrast medium (LOCM). First of all, we applied the frequently used pretreatments (uninephrectomy and water deprivation), which combined with HOCM on rats could induce CI-AKI, on mice with LOCM. Secondly, we attempted to find a novel pretreatment suitable for mouse and LOCM by combining two classic pretreatments(uninephrectomy, water deprivation and furosemide administration). Finally, we evaluate the kidney damage of the novel model. We found that this mouse model possessed a significant reduction in renal function, severe renal tissue damage, and increased renal tubular cells apoptosis, indicating that LOCM is a feasible inducer for CI-AKI mice model. Taken together, we found that uninephrectomy (UPHT) combined with 24 h water deprivation and furosemide administration 20 min before LOCM (iohexol, 10 ml/kg) application is a feasible pretreatment to establish a novel CI-AKI mouse model.

Predicting Progression of Kidney Injury Based on Elastography Ultrasound and Radiomics Signatures

Background: Shear wave elastography ultrasound (SWE) is an emerging non-invasive candidate for assessing kidney stiffness. However, its prognostic value regarding kidney injury is unclear. Methods: A prospective cohort was created from kidney biopsy patients in our hospital from May 2019 to June 2020. The primary outcome was the initiation of renal replacement therapy or death, while the secondary outcome was eGFR < 60 mL/min/1.73 m2. Ultrasound, biochemical, and biopsy examinations were performed on the same day. Radiomics signatures were extracted from the SWE images. Results: In total, 187 patients were included and followed up for 24.57 ± 5.52 months. The median SWE value of the left kidney cortex (L_C_median) is an independent risk factor for kidney prognosis for stage 3 or over (HR 0.890 (0.796−0.994), p < 0.05). The inclusion of 9 out of 2511 extracted radiomics signatures improved the prognostic performance of the Cox regression models containing the SWE and the traditional index (chi-square test, p < 0.001). The traditional Cox regression model had a c-index of 0.9051 (0.8460−0.9196), which was no worse than the machine learning models, Support Vector Machine (SVM), SurvivalTree, Random survival forest (RSF), Coxboost, and Deepsurv. Conclusions: SWE can predict kidney injury progression with an improved performance by radiomics and Cox regression modeling.

Automated Peritoneal Dialysis in Urgent-Start Dialysis ESRD Patients:Safety and Dialysis Adequacy

BACKGROUND

Recent evidence suggests that automated peritoneal dialysis (APD) might be a feasible alternative to hemodialysis (HD) in urgent-start peritoneal dialysis.

METHODS

This prospective study enrolled ESRD patients who had started APD as an urgent-start dialysis modality at a single center. Dialysis-related complications were recorded. Dialysis adequacy and electrolytes imbalance were compared between baseline, 14 days and 42 days after catheter insertion. Technique survival and patient survival were also recorded.

RESULTS

A total of 36 patients were included in the study. Mean follow-up duration was 22 months. During the follow-up, 11 PD patients(30.6%) developed dialysis-related complications. Only two patients(5.6%) required re-insertion and one patients(2.8%) transfer to HD. The 2-year technique survival rate and patient survival rate were 94.4% and 97.2% , respectively.

CONCLUSION

In considering safety and dialysis adequacy, APD could be a feasible dialysis modality for urgent-start dialysis in ESRD patients, using a standard procedure.

C4d as a Screening Tool and an Independent Predictor of Clinical Outcomes in Lupus Nephritis and IgA Nephropathy

Background

As an indispensable marker of complement cascades activation, C4d was confirmed of its crucial role in the pathogenesis of both lupus nephritis (LN) and IgA nephropathy (IgAN). While the studies directly comparing the diagnostic value, and outcomes predicting function of C4d between LN and IgAN are still absent.

Methods

A cohort of 120 LN patients, 120 IgAN patients who were diagnosed by renal biopsy between January 2015 and December 2017 and 24 healthy age matched controls were prospectively analyzed. The patients were followed till December 2020. The outcomes were adverse disease treatment response (disease relapse) and kidney disease progression event (decline of estimated glomerular filtration rate by more than 20% or end-stage kidney disease). The renal C4d deposition proportion and pattern were compared between IgAN and LN patients. In addition, the relationship between renal C4d deposition and disease subtypes, disease relapse as well as disease progression for LN and IgAN patients were also analyzed.

Results

The LN, IgAN patients and healthy controls were well matched in ages. The follow-up period was 38.5 (30.3–60.8) months for LN patients and 45.0 (30.5–57.0) months for IgAN patients. 78 patients (65.0%) with LN had renal C4d deposition, compared with only 39 IgAN patients (32.5%) with C4d deposition in renal tissues (P < 0.001). The LN patients shared different renal C4d distribution patterns with IgAN patients. Compared with IgAN patients, the C4d deposition in LN patients was significantly more in renal glomerulus (P < 0.001) and less in renal tubules (P = 0.003). For disease subtypes, renal C4d deposition was especially strong in class V membranous LN and IgAN with tubulointerstitial fibrosis (T1/T2) lesions. Renal C4d deposition was independently correlated with the disease relapse of LN patients (HR = 1.007, P = 0.040), and acted as an independent predictor of disease progression during the follow-up period for IgAN patients (HR = 1.821, P = 0.040).

Conclusions

Renal C4d distribution proportion and pattern differed between LN and IgAN patients. The presence of C4d in renal tissue acted as an independent predictor of relapse for LN patients and disease progression for IgAN patients.

The predictive value of urinary kidney injury molecular-1 for long-term graft function in kidney transplant patients: a prospective study

Background

Monitoring allograft function during the early stages is crucial, and therefore requires biomarkers more sensitive than serum creatinine (Scr). Kidney injury molecular-1 (KIM-1) is a potent biomarker; however, disparities exist in the literature concerning its predictive value in allograft function. Therefore, this study aimed to evaluate its predictive value for the long-term prognosis of kidney transplantation patients.

Methods

A prospective study with a cohort comprising 160 patients scheduled for kidney transplantation was conducted to evaluate the predictive power of urinary KIM-1 (uKIM-1) and other renal ischemia-reperfusion biomarkers including urinary L-type fatty acid binding protein (uL-FABP), urinary N-acetyl-β-D glucosaminidase (uNAG), and urinary neutrophil gelatinase-related lipoprotein (uNGAL) for allograft prognosis.

Results

One hundred and forty kidney recipients who were admitted to our hospital between September 2014 and December 2017 with a median follow-up of 30.3 months were included. Thirty-seven recipients had functional delayed graft function (fDGF) in the first week post transplantation, and 42 recipients had progressed to allograft dysfunction [estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m²] by the end of the study, while nine recipients deteriorated into allograft loss (defined by the initiation of dialysis). The levels of uKIM-1 in the fDGF group were higher than those in the immediate graft function (IGF) recipients (P<0.05) at 0 hour post transplantation [5.885 (4.420–7.913) vs. 4.605 (3.417–5.653) ng/mmol], and on the first day post transplantation [5.569 (4.181–6.722) vs. 4.002 (3.222–6.488) ng/mmol]. The levels of uL-FABP in the fDGF group were also higher than those in the IGF group at 0 hour post transplantation (89.818±39.332 vs. 69.187±37.926 µg/mmol) and on the third day post transplantation [77.835 (60.368–100.678) vs. 66.841 (28.815–89.783) µg/mmol]. Multivariate Cox regression analysis demonstrated that recipients with higher uKIM-1 levels on the first day post transplantation had a 23.5% increase in the risk of developing fDGF and a 27.3% increase in the risk of prolonged renal allograft dysfunction.

Conclusions

uKIM-1 on the first day post transplantation can predict short-term graft function and is a potent biomarker for the long-term prognosis of graft function.

Integrated Analysis of m6A Methylome in Cisplatin-Induced Acute Kidney Injury and Berberine Alleviation in Mouse

Background

N6-methyladenosine (m6A) is the most abundant modification known in mRNAs. It participates in a variety of physiological and pathological processes, such as metabolism, inflammation, and apoptosis.

Aims

To explore the mechanism of m6A in cisplatin-induced acute kidney injury (AKI) and berberine alleviation in mouse.

Methods

This study investigated the N6-methyladenosine (m6A) methylome of kidneys from three mouse groups: C57 mice (controls), those with CI-AKI (injury group, IG), and those pretreated with berberine (treatment group, TG). Methylated RNA Immunoprecipitation Next Generation Sequencing (MeRIP-seq) and RNA-seq were performed to identify the differences between the injury group and the control group (IvC) and between the treatment group and the injury group (TvI). Western blotting was performed to identify the protein levels of candidate genes.

Results

In IvC, differentially methylated genes (DMGs) were enriched in metabolic processes and cell death. In TvI, DMGs were enriched in tissue development. Several genes involved in important pathways related to CI-AKI showed opposite methylation and expression trends in the IvC and TvI comparisons.

Conclusion

m6A plays an important role in cisplatin induced AKI and berberine may alleviate this process.

Long noncoding RNA MEG3 suppresses podocyte injury in diabetic nephropathy by inactivating Wnt/β-catenin signaling

Background

Diabetic nephropathy (DN) is one of the principal complications of diabetes and podocyte injury plays an important role in the DN pathogenesis. Wnt/β-catenin signaling overactivation confers podocyte injury and promotes multiple types of renal disease. However, the underlying mechanism of Wnt/β-catenin signaling activation in DN progression has not been fully elucidated. Long noncoding RNA (lncRNA) is a large class of endogenous RNA molecules lacking functional code capacity and which participates in the pathogenesis of human disease, including DN.

Method

A diabetes model was constructed by intraperitoneal injection of Streptozotocin in rats. The MPC5 cells were used to create the in vitro model. Western blot and Quantitative reverse-transcriptase-PCR were used to examine the expression of protein and mRNA. The migrated capacity was analyzed by Transwell migration assay. The cell viability was detected by CCK8.

Results

In the present study, we revealed the association of lncRNA Maternally Expressed Gene 3 (MEG3) with aberrant activation of Wnt/β-catenin signaling and the role of MEG3/Wnt axis in podocyte injury. We found that high glucose (HG) treatment suppressed MEG3 expression in cultured podocytes, activated Wnt/β-catenin signaling and caused podocyte injury as indicated by the downregulation of podocyte-specific markers (podocin and synaptopodin) and the upregulation of snail1 and α-smooth muscle actin. Overexpression of MEG3 attenuated HG-induced podocyte injury by reducing Wnt/β-catenin activity, repressing cell migration, reactive oxygen species production and increasing the viability of podocytes. Furthermore, we provided evidences that restoration of Wnt/β-catenin signaling by specific agonist impeded the protective effect of MEG3 on podocyte injury. Current results demonstrated that MEG3/Wnt axis plays an important role in fostering podocyte injury and may serve as a potential therapeutic target for the treatment of DN.

Conclusion

lncRNA MEG3 ameliorates podocyte injury in DN via inactivating Wnt/β-catenin signaling.

Peritoneal Dialysis as an Option for Unplanned Dialysis Initiation in Patients with End-Stage Renal Disease and Diabetes Mellitus

<b><i>Aims:</i></b> This study aimed to compare the short-term complications and long-term prognosis between urgent-start peritoneal dialysis (PD) and hemodialysis (HD), and explore the safety and feasibility of PD in end-stage renal disease (ESRD) patients with diabetes. <b><i>Methods:</i></b> This retrospective study enrolled ESRD patients with diabetes who required urgent-start dialysis at a single center from January 2011 to December 2014. Short-term (30-day) dialysis-related complications and patient survival trends were compared between patients receiving PD and HD. <b><i>Results:</i></b> Eighty patients were included in the study, including 50 (62.5%) who underwent PD. The incidence of dialysis-related complications and complications requiring reinsertion during the first 30 days was significantly lower in PD patients. Logistic regression identified urgent-start HD as an independent risk factor for dialysis-related complications compared with urgent-start PD. The patient survival rate was higher in the PD compared to that in the HD group. <b><i>Conclusions:</i></b> PD may be acceptable, safe, and feasible for urgent-start dialysis in ESRD patients with diabetes.

Effects of pretransplant peritoneal vs hemodialysis modality on outcome of first kidney transplantation from donors after cardiac death

Background

The effect of pretransplant peritoneal dialysis (PD) or hemodialysis (HD) modality on outcomes of kidney transplantation (KT) for end-stage renal disease (ESRD) is debatable. We evaluated the outcomes these modalities in KT from donor after cardiac death (DCD).

Methods

A cohort of 251 patients on HD, PD or pre-emptive who underwent first KT from DCD between January 2014 and December 2016 were prospectively analyzed to compare for outcomes on recovery of renal function, complications as well as patient and graft survival. The patients were followed till August 2017. Data on 104 HD and 98 PD were available for final comparative outcome analysis, 5 pre-emptive were analyzed as the control group.

Results

Both HD and PD group patients were well matched for demographic and baseline characteristics. The follow-up period was 12.5 (3.0, 22.0) months in HD and 12.0 (6.0, 20.0) months in PD patients. Post-transplant renal functions between the two groups showed no differences. Among PD patients, 16 (16.3%) suffered delayed graft function, versus 19 (18.3%) in HD, with no statistical differences (p = 0.715). Complications of acute rejection, infections were comparable between the groups. The patient survival, graft survival and death-censored graft survival were similar for HD and PD after adjusting for other multiple risk factors.

Conclusions

Our results indicate that outcome of first KT from DCD is not affected by pretransplant dialysis modality of PD or HD in aspects of recovery of renal function, complications as well as patient and graft survival.

Comparison of combined leflunomide and low-dose corticosteroid therapy with full-dose corticosteroid monotherapy for progressive IgA nephropathy

IgA nephropathy is the most common primary glomerulonephritis and one of the leading causes of end-stage renal disease. We performed a randomized, controlled, prospective, open-label trial to determine whether leflunomide combined with low-dose corticosteroid is safe and effective for the treatment of progressive IgA nephropathy, as compared to full-dose corticosteroid monotherapy. Biopsy-proved primary IgA nephropathy patients with an estimated glomerular filtration rate ≥ 30 ml/min/1.73m² and proteinuria ≥1.0 g/24h were randomly assigned to receive leflunomide+low-dose corticosteroid (leflunomide group; n = 40) or full-dose corticosteroid (corticosteroids group; n = 45). The primary outcome was renal survival; secondary outcomes were proteinuria and adverse events. After 12 months of treatment and an average follow-up of 88 months, 11.1% vs. 7.5% of patients reached end-stage renal disease and 20% versus 10% of patients had a ≥ 50% increase in serum creatinine in the corticosteroids and leflunomide groups, respectively. Kaplan-Meier analysis did not reveal a between-group difference in these outcomes. Decreases in 24-hour proteinuria were similar in the two groups during the treatment period, but a more marked reduction was observed during follow-up in the leflunomide group. Although the incidence of adverse events was similar in the two groups, serious adverse events were observed only in the corticosteroid group. Thus, leflunomide combined with low-dose corticosteroid is at least as effective as corticosteroid alone for the treatment of progressive IgA nephropathy, and showed a greater reduction of proteinuria during long-term follow-up and fewer severe adverse events.

A case of ureteral myeloid sarcoma post-renal transplantation

Background

Significant attention has been directed toward the high incidence of malignant tumours that occur post-transplantation. However, there are few reports of myeloid sarcomas (MSs) following renal transplantation.

Case presentation

This case report describes a 26-year-old male patient who presented with repeatedly high creatinine levels and hydronephrosis six months post-renal transplantation. Surgical pathology revealed ureteral MS; however, the tumour recurred following resection. Bone marrow biopsy indicated that the patient also had acute promyelocytic leukaemia. The tumour was treated with local radiotherapy, and the leukaemia was treated with systemic chemotherapy. The patient’s conditions were satisfactory at the one-year follow-up.

Conclusions

This report is the first to describe a ureteral MS post-renal transplantation. Our findings suggest that surgical resection combined with radiotherapy and chemotherapy can help control the status of patients with this condition.

Exosomes promote cetuximab resistance via the PTEN/Akt pathway in colon cancer cells

Cetuximab is widely used in patients with metastatic colon cancer expressing wildtype KRAS. However, acquired drug resistance limits its clinical efficacy. Exosomes are nanosized vesicles secreted by various cell types. Tumor cell-derived exosomes participate in many biological processes, including tumor invasion, metastasis, and drug resistance. In this study, exosomes derived from cetuximab-resistant RKO colon cancer cells induced cetuximab resistance in cetuximab-sensitive Caco-2 cells. Meanwhile, exosomes from RKO and Caco-2 cells showed different levels of phosphatase and tensin homolog (PTEN) and phosphor-Akt. Furthermore, reduced PTEN and increased phosphorylated Akt levels were found in Caco-2 cells after exposure to RKO cell-derived exosomes. Moreover, an Akt inhibitor prevented RKO cell-derived exosome-induced drug resistance in Caco-2 cells. These findings provide novel evidence that exosomes derived from cetuximab-resistant cells could induce cetuximab resistance in cetuximab-sensitive cells, by downregulating PTEN and increasing phosphorylated Akt levels.

[Surgical treatment and prognosis of pancreatic neuroendocrine carcinoma]

Objective: Pancreatic neuroendocrine carcinoma (pNEC) is a highly malignant tumor.This study aimed to evaluate the role of surgery and the prognosis for patients with pancreatic neuroendocrine carcinoma (pNEC). Methods: We collected and reviewed all clinical data of patients who underwent radical surgery for pNEC from Jan 2000 through Jan 2016 in our hospital. Cox-regression analysis wasused to evaluate the factors potentially influencing survival. Results: Twenty patients including 11 males and 9 females (median age, 62.5 years) were included in this study. All patients underwent radical surgery and 17 cases received postoperative platinum-based chemotherapy.The median follow-up time was 41 months (range, 1 to 127 months). The 1-, 3-, and 5-year survival rates of the patients were 66.7%, 51.5% and 28.1%, with a median survival time of 75.3 months.The multivariate analysis indicated that tumor size and Ki-67 index were of prognostic significance. Conclusions: Pancreatic neuroendocrine carcinomas are rare but increasing in incidence. Patients with localized nonmetastatic primary tumors seem to benefit from surgery. Early diagnosis and multimodality therapy are key points of an improved survival.

The impact of non-dipper circadian rhythm of blood pressure on left ventricular hypertrophy in patients with non-dialysis chronic kidney disease

Objective The aim of this study was to investigate the correlation between non-dipper circadian rhythm of blood pressure (BP) and left ventricular hypertrophy (LVH) in patients with chronic kidney disease (CKD). Methods and results All 257 patients with stage 1 to 5 CKD were enrolled in the study and classified into a CKD1-3 group and a CKD4-5 group according to renal function. The parameters and circadian rhythm of BP were measured by a GE Marquette Tonoport V Eng dynamic sphygmomanometer, and cardiac structure was examined by echocardiography. The incidence of abnormal circadian BP rhythm (non-dipper rhythm) was quite high (75.4% in all enrolled patients and 71.3% in the patients with normal BP levels) in CKD patients and increased with the deterioration of renal function. Changes of cardiac structure such as LVH in patients with non-dipper BP were more distinct than in patients with dipper BP. The development of left ventricular mass index (LVMI) correlated positively with the incidence of non-dipper BP rhythm. Multiple regression analysis showed that 24-h systolic BP (β = 0.417, P < 0.01), triglycerides (TG) (β = -0.132, P = 0.007), Hb (β = -0.394, P = 0.016) and gender (β = 0.158, P = 0.039) were independent risk factors of LVMI. Conclusions The incidence of non-dipper circadian rhythm of blood pressure was quite high in CKD patients and increased with the deterioration of renal function. Non-dipper circadian rhythm of BP is closely related with LVMI.

Kidney Injury Molecule-1 is Elevated in Nephropathy and Mediates Macrophage Activation via the Mapk Signalling Pathway

BACKGROUND/AIMS

Kidney injury molecule-1 (KIM-1) is highly expressed in renal tubular cells after injury and is usually regarded as an early biomarker of acute kidney injury(AKI). The aim of this study was to determine the role of KIM-1 in the development of renal tubular injury Methods: Clinical samples, three different animal models and in vitro experiments were utilized to determine the possible mechanism underlying the involvement of KIM-1 in kidney injury.

RESULTS

Both plasma and urinary KIM-1 expression levels were significantly higher in AKI and chronic kidney disease (CKD) patients than in healthy volunteers, and urinary KIM-1 expression was significantly higher in CKD patients than in AKI patients. According to the results of our research involving three different mouse models, KIM-1 expression was significantly increased during the early stage of kidney injury and was persistently elevated in renal fibrosis. Our immunofluorescence staining results indicated that KIM-1-positive tubules were surrounded by macrophage infiltrates in regions of kidney injury. Moreover, our transwell, western blotting and real-time PCR data showed that macrophage migration and phenotype transitions were mediated by KIM-1 through the mitogen-activated protein kinase (MAPK) pathway. MAPK pathway inhibition could significantly reverse the effects of KIM-1 with respect to these macrophage phenotype changes and migration.

CONCLUSIONS

KIM-1 expression was markedly elevated in both acute and chronic kidney injury and may play a pivotal role in macrophage activation via the MAPK pathway in kidney disease.

Association between the levels of urine kidney injury molecule-1 and the progression of acute kidney injury in the elderly

Background

The factors influencing the prognosis of acute kidney injury (AKI) were analyzed in a group of elderly AKI patients to determine the markers of early prognosis.

Methods

A total of 258 patients were screened, and 201 patients were enrolled in the study. Eventually, 184 AKI patients were included in the study, including 79 elderly AKI patients (≥60 years old). During one year of follow-up, renal function changes were observed, and the risk factors that influenced the prognosis of AKI were analyzed.

Results

When AKI occurred, the urine kidney injury molecule-1 (uKIM-1) level was significantly higher in the progressive deterioration of renal function group than in the renal function stable group. The ROC curve analysis revealed that the area under the curve for poor progressive deterioration of renal function as predicted by the uKIM-1 level was 0.681. At a cutoff point of 2.46 ng/mg, the sensitivity was 71.9% and the specificity was 70.0%. In elderly AKI patients, uKIM-1 levels exceeding 2.46 ng/mg were positively associated with poor kidney prognosis.

Conclusions

Elderly AKI patients are at risk of developing progressive deterioration of renal function. In elderly AKI patients, the high uKIM-1 level may predict the prognosis of kidney function and may be used as an early screening indicator of poor kidney prognosis.

Urgent-Start Peritoneal Dialysis and Hemodialysis in ESRD Patients: Complications and Outcomes

Background

Several studies have suggested that urgent-start peritoneal dialysis (PD) is a feasible alternative to hemodialysis (HD) in patients with end-stage renal disease (ESRD), but the impact of the dialysis modality on outcome, especially on short-term complications, in urgent-start dialysis has not been directly evaluated. The aim of the current study was to compare the complications and outcomes of PD and HD in urgent-start dialysis ESRD patients.

Methods

In this retrospective study, ESRD patients who initiated dialysis urgently without a pre-established functional vascular access or PD catheter at a single center from January 2013 to December 2014 were included. Patients were grouped according to their dialysis modality (PD and HD). Each patient was followed for at least 30 days after catheter insertion (until January 2016). Dialysis-related complications and patient survival were compared between the two groups.

Results

Our study enrolled 178 patients (56.2% male), of whom 96 and 82 patients were in the PD and HD groups, respectively. Compared with HD patients, PD patients had more cardiovascular disease, less heart failure, higher levels of serum potassium, hemoglobin, serum albumin, serum pre-albumin, and lower levels of brain natriuretic peptide. There were no significant differences in gender, age, use of steroids, early referral to a nephrologist, prevalence of primary renal diseases, prevalence of co-morbidities, and other laboratory characteristics between the groups. The incidence of dialysis-related complications during the first 30 days was significantly higher in HD than PD patients. HD patients had a significantly higher probability of bacteremia compared to PD patients. HD was an independent predictor of short-term (30-day) dialysis-related complications. There was no significant difference between PD and HD patients with respect to patient survival rate.

Conclusion

In an experienced center, PD is a safe and feasible dialysis alternative to HD for ESRD patients with an urgent need for dialysis.

NLRP3 inflammasome mediates contrast media-induced acute kidney injury by regulating cell apoptosis

Iodinated contrast media serves as a direct causative factor of acute kidney injury (AKI) and is involved in the progression of cellular dysfunction and apoptosis. Emerging evidence indicates that NLRP3 inflammasome triggers inflammation, apoptosis and tissue injury during AKI. Nevertheless, the underlying renoprotection mechanism of NLRP3 inflammasome against contrast-induced AKI (CI-AKI) was still uncertain. This study investigated the role of NLRP3 inflammasome in CI-AKI both in vitro and in vivo. In HK-2 cells and unilateral nephrectomy model, NLRP3 and NLRP3 inflammasome member ASC were significantly augmented with the treatment of contrast media. Moreover, genetic disruption of NLRP3 notably reversed contrast-induced expression of apoptosis related proteins and secretion of proinflammatory factors, similarly to the effects of ASC deletion. Consistent with above results, absence of NLRP3 in mice undergoing unilateral nephrectomy also protected against contrast media-induced renal cells phenotypic alteration and cell apoptosis via modulating expression level of apoptotic proteins. Collectively, we demonstrated that NLRP3 inflammasome mediated CI-AKI through modulating the apoptotic pathway, which provided a potential therapeutic target for the treatment of contrast media induced acute kidney injury.

Simulation Studies of Protein and Small Molecule Interactions and Reaction

Computational studies of protein and small molecule (protein-ligand/enzyme-substrate) interactions become more and more important in biological science and drug discovery. Computer modeling can provide molecular details of the processes such as conformational change, binding, and transportation of small molecules/proteins, which are not easily to be captured in experiments. In this chapter, we discussed simulation studies of both protein and small molecules from three aspects: conformation sampling, transportations of small molecules in enzymes, and enzymatic reactions involving small molecules. Both methodology developments and examples of simulation studies in this field were presented.

No Sun-like dynamo on the active star ζ Andromedae from starspot asymmetry

Sunspots are cool areas caused by strong surface magnetic fields that inhibit convection. Moreover, strong magnetic fields can alter the average atmospheric structure, degrading our ability to measure stellar masses and ages. Stars that are more active than the Sun have more and stronger dark spots than does the Sun, including on the rotational pole. Doppler imaging, which has so far produced the most detailed images of surface structures on other stars, cannot always distinguish the hemisphere in which the starspots are located, especially in the equatorial region and if the data quality is not optimal. This leads to problems in investigating the north-south distribution of starspot active latitudes (those latitudes with more starspot activity); this distribution is a crucial constraint of dynamo theory. Polar spots, whose existence is inferred from Doppler tomography, could plausibly be observational artefacts. Here we report imaging of the old, magnetically active star ζ Andromedae using long-baseline infrared interferometry. In our data, a dark polar spot is seen in each of two observation epochs, whereas lower-latitude spot structures in both hemispheres do not persist between observations, revealing global starspot asymmetries. The north-south symmetry of active latitudes observed on the Sun is absent on ζ And, which hosts global spot patterns that cannot be produced by solar-type dynamos.

Cytokine network analysis of cerebrospinal fluid in myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome is an unexplained debilitating disorder that is frequently associated with cognitive and motor dysfunction. We analyzed cerebrospinal fluid from 32 cases, 40 subjects with multiple sclerosis and 19 normal subjects frequency-matched for age and sex using a 51-plex cytokine assay. Group-specific differences were found for the majority of analytes with an increase in cases of CCL11 (eotaxin), a chemokine involved in eosinophil recruitment. Network analysis revealed an inverse relationship between interleukin 1 receptor antagonist and colony-stimulating factor 1, colony-stimulating factor 2 and interleukin 17F, without effects on interleukin 1α or interleukin 1β, suggesting a disturbance in interleukin 1 signaling. Our results indicate a markedly disturbed immune signature in the cerebrospinal fluid of cases that is consistent with immune activation in the central nervous system, and a shift toward an allergic or T helper type-2 pattern associated with autoimmunity.

Astragaloside IV suppresses transforming growth factor-β1 induced fibrosis of cultured mouse renal fibroblasts via inhibition of the MAPK and NF-κB signaling pathways

Renal fibrosis, a progressive process characterized by the accumulation of extracellular matrix (ECM) leading to organ dysfunction, is a characteristic of chronic kidney diseases. Among fibrogenic factors known to regulate the renal fibrotic process, transforming growth factor-β (TGF-β) plays a central role. In the present study, we examined the effect of Astragaloside IV (AS-IV), a component of the traditional Chinese medicinal plant Astragalus membranaceus, on the processes associated with renal fibrosis in cultured mouse renal fibroblasts treated with TGF-β1. RT-PCR, western blotting, immunofluorescence staining and collagen assays showed that AS-IV suppressed TGF-β1 induced fibroblast proliferation, transdifferentiation, and ECM production in a dose-dependent manner. Examination of the underlying mechanisms showed that the effect of AS-IV on the inhibition of fibroblast differentiation and ECM formation were mediated by its modulation of the activity of the MAPK and NF-κB signaling pathways. Taken together, our results indicate that AS-IV alleviates renal interstitial fibrosis via a mechanism involving the MAPK and NF-κB signaling pathways and demonstrate the therapeutic potential of AS-IV for the treatment of chronic kidney diseases.

Long-term kidney survival analyses in IgA nephropathy patients under steroids therapy: a case control study

Background

Corticosteroids are preferred to treat patients with active IgA nephropathy (IgAN), and beneficial effects from the short-term use of corticosteroids have been confirmed. However, a large number of patients will progress to end-stage renal disease after a long time follow-up. This study aimed to evaluate kidney disease progression and risk factors on kidney survival in IgAN patients receiving steroids treatment.

Methods

Two hundred biopsy-proven IgAN patients who received corticosteroid therapy were enrolled and followed for a median period of 63.33 months. Risk factors on kidney survival were retrospectively investigated by the Cox proportional hazards model.

Results

Of the two hundred patients, twenty patients showed progression of renal impairment at the end of follow-up. The median and interquartile range values for initial serum creatinine were 89.2 and 68.08–121.35 µmol/L, respectively. Multivariate Cox regression analyses revealed that relapse, non-remission, time-averaged eGFR (TA-eGFR), and time-averaged serum albumin (TA-ALB) were independently associated with the kidney progression. Those with TA-ALB levels <35 g/L and TA-eGFR levels <60 mL/min/1.73 m² were less likely to recover from kidney progression. Patients were more likely to show kidney function deterioration, when they had non-remission or relapse after corticosteroids treatment.

Conclusion

This study demonstrated that relapse, non-remission, TA-eGFR, and TA-ALB could serve as independent predictors of long term prognosis of IgAN patients receiving corticosteroid therapy.

The long-term efficacy and safety of immunosuppressive therapy on the progression of IgA nephropathy: a meta-analysis of controlled clinical trials with more than 5-year follow-up

OBJECTIVE

To evaluate the long-term efficacy of immunosuppressive therapy on Immunoglobulin A nephropathy (IgAN).

METHODS

Trials with at least 5-year follow-up investigating immunosuppressive therapy were selected.

MAIN OUTCOME MEASURES

Primary outcome was end-stage renal disease (ESRD). Secondary outcome was deterioration in renal function defined as doubled serum creatinine or 50% reduction of eGFR.

RESULTS

Seven studies were enrolled. Immunosuppression lowered the risk for ESRD risk ratio (RR = 0.30, 95% CI 0.19 - 0.48, p < 0.00001) and deterioration in renal function (RR = 0.19, 95% CI 0.07 - 0.54, p = 0.002). As for pooled RRs of ESRD, there were four studies with < 7-year follow-up, three followed for > 7 years, four adopted corticosteroids, two used corticosteroids plus other immunosuppressive agents, four were from Asia, and three from Europe. Pooled RRs were 0.32 (95% CI, 0.18 - 0.58, p = 0.0001), 0.28 (95% CI, 0.13 - 0.59, p = 0.0009), 0.34 (95% CI, 0.17 - 0.67, p = 0.002), 0.29 (95% CI, 0.15 - 0.58, p = 0.0005), 0.37 (95% CI, 0.20 - 0.68, p = 0.001) and 0.23 (95% CI, 0.11 - 0.47, p < 0.0001), respectively. Immunosuppression was associated with an increased risk for adverse events (RR = 2.13, 95% CI 1.17 - 3.86, p = 0.01).

CONCLUSIONS

Immunosuppressive therapy for IgAN might reduce long-term risk of ESRD and deterioration in renal function but increase risk of adverse events, and the efficacy on patients from Europe and Asia might be similar. Addition of other immunosuppressive agents did not provide additional benefit.

Preliminary Survey of Ectoparasites and Associated Pathogens from Norway Rats in New York City

The Norway rat (Rattus norvegicus) is a reservoir of many zoonotic pathogens and lives in close proximity to humans in urban environments. Human infection with rodent-borne disease occurs either directly through contact with a rat or its excreta, or indirectly via arthropod vectors such as fleas and ticks. Here, we report on the diversity and abundance of ectoparasitic arthropod species and associated pathogenic bacteria from 133 Norway rats trapped over a 10-mo period in Manhattan, New York, NY. Norway rats were host to the tropical rat mite [Ornithonyssus bacoti (Hirst)], the spiny rat mite (Laelaps echidnina Berlese), Laelaps nuttalli Hirst, the spined rat louse [Polyplax spinulosa (Burmeister)], and the Oriental rat flea [(Xenopsylla cheopis) (Rothschild)], with an average of 1.7 species per individual. A flea index of 4.1 X. cheopis was determined, whereas previous studies in New York City reported 0.22 fleas per rat. Multiple species of pathogenic Bartonella were identified from Oriental rat fleas that were related to Bartonella tribocorum, Bartonella rochalimae, and Bartonella elizabethae. However, no evidence of Yersinia pestis or Rickettsia spp. infection was detected in fleas. The identification of multiple medically important ectoparasite species in New York City underscores the need for future efforts to fully characterize the diversity and distribution of ectoparasites on Norway rats, and assess the risk to humans of vector-borne disease transmission.

Identification of mannose-binding lectin as a mechanism in progressive immunoglobulin A nephropathy

Immunoglobulin A nephropathy (IgAN), the pathogenesis of which remained still unclear is one of the leading courses of end-stage renal disease in approximately 50% affected patients. On the basis of several researches, the activation of complement mannose-binding lectin (MBL) pathway might be the underlying mechanism in disease progress. In order to investigate the relationship between MBL pathway and IgAN, we discussed the MBL gene polymorphism as well as its expressed level in serum, urine and renal parenchymal, with renal outcome in IgAN patients. The significantly down-regulated expression of MBL was discovered, which may serve as a potential urinary biomarker in progressive IgAN according to the results of difference in gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The single nucleotide polymorphisms of MBL gene in promoter and exon region were found and confirmed relating with the poor prognosis of progressive IgAN patients. As a result, the deficient activation of MBL pathway caused by the mutation of MBL accompanied with low expressed level of MBL in serum might be the potential inspiring regulation in IgAN, and will attract a promising insight in remedy of IgAN to inhibit further progress.

Blood HCO3 - concentration predicts the long-term prognosis of acute kidney injury patients

Aim: To evaluate the value of HCO3 - concentrations in long-term prognosis after acute kidney injury. Patients & methods: A total of 169 AKI patients were included in this study. At the 12‐month follow-up, the patients were divided into recovered and unrecovered groups. Results: The blood HCO3 - concentrations were significantly correlated with poor prognosis. The area under the curve for renal prognosis of 6 months later blood HCO3 - concentrations was 0.798. Combined HCO3 - and Scr level area under the curve was 0.952. Conclusion: The blood HCO3 - level was useful in evaluating renal prognosis of acute kidney injury patients. The combination of blood HCO3 - concentration and Scr level increased the accuracy of prediction.

Time-averaged albumin predicts the long-term prognosis of IgA nephropathy patients who achieved remission

Background

Primary IgA nephropathy (IgAN) is the most common form of idiopathic glomerulonephritis worldwide. Although most patients are able to achieve remission with the current therapy, a large number of patients will still progress to end-stage renal disease. This study aimed to evaluate kidney disease progression and the risk factors for progression in IgAN patients who achieved remission.

Methods

Patients from a prospective database with IgAN were included in this study. All the subjects had achieved a complete remission (CR) or partial remission (PR) following 6 months of therapy. Renal survival and the relationship between the clinical parameters and composite renal outcomes were assessed.

Results

The study comprised 878 IgAN patients recruited between January 2005 and December 2010. Overall, 632 patients were enrolled in this study. The data from the 369 patients who achieved remission were analyzed; the mean follow-up time was 49 months. The median serum creatinine (SCr) concentration at baseline was 91.3 μmol/L, and the time-averaged creatinine (TA-SCr) was 91.8 μmol/L. The mean serum albumin (ALB) level at baseline was 39.4 g/L, and the time-averaged serum albumin (TA-ALB) was 42.1 g/L. Multivariate Cox regression analyses revealed that the TA-ALB and TA-SCr levels were independently associated with the composite renal outcome. The patients with a TA-SCr value > 120 μmol/L and a TA-ALB level < 38 g/L were less likely to recover from renal progression.

Conclusion

The strong predictive relationship of low TA-ALB and high TA-SCr levels with progression observed in this study suggests that TA-ALB may serve as a marker of the long-term renal prognosis of IgAN patients who have achieved remission.

Generalized linear mixed models for mapping multiple quantitative trait loci

Many biological traits are discretely distributed in phenotype but continuously distributed in genetics because they are controlled by multiple genes and environmental variants. Due to the quantitative nature of the genetic background, these multiple genes are called quantitative trait loci (QTL). When the QTL effects are treated as random, they can be estimated in a single generalized linear mixed model (GLMM), even if the number of QTL may be larger than the sample size. The GLMM in its original form cannot be applied to QTL mapping for discrete traits if there are missing genotypes. We examined two alternative missing genotype-handling methods: the expectation method and the overdispersion method. Simulation studies show that the two methods are efficient for multiple QTL mapping (MQM) under the GLMM framework. The overdispersion method showed slight advantages over the expectation method in terms of smaller mean-squared errors of the estimated QTL effects. The two methods of GLMM were applied to MQM for the female fertility trait of wheat. Multiple QTL were detected to control the variation of the number of seeded spikelets.