Estrogens and the diabetic kidney

Background: Across all ages, the incidence and rate of progression of most nondiabetic renal diseases are markedly higher in men compared with age-matched women. These observations suggest that female sex may be renoprotective. In the setting of diabetes, however, this female protection against the development and progression of renal disease is diminished.Objective: This review aimed to summarize our current understanding of sex differences in the development and progression of diabetic renal disease, and of the contribution of sex hormones, particularly estrogens, to the pathophysiology of this disease. We also attempted to answer why female sex does not protect the diabetic kidney.Methods: Using terms such as gender, sex, diabetes, diabetic nephropathy, estrogens, and sex hormones, the PubMed database was searched for English-language articles; targeted searches were conducted using terms such as gender/sex differences in diabetic renal disease. No restrictions were imposed on publication dates.Results: Although the existing data regarding the sex differences in the incidence and progression of diabetic renal disease are inconclusive, the undisputed fact is that women with either type 1 or type 2 diabetes mellitus exhibit a much higher incidence of renal disease compared with nondiabetic women. It is conceivable that the loss of female sex as a renoprotective factor in diabetes may be related to the abnormal regulation of sex hormone concentrations. Both clinical and experimental data suggest that diabetes may be associated with an imbalance in estradiol concentrations. Supplementation with 17β-estradiol or administration of selective estrogen receptor modulators reduces the incidence of diabetes and attenuates the progression of diabetic renal disease.Conclusions: Serum concentrations of ovarian hormones may provide a new means for predicting future risk of renal complications in diabetes. Exogenous steroid hormones may be an effective treatment for attenuating the progression of diabetic nephropathy.     

The Association of Serum Bilirubin on Kidney Clinicopathologic Features and Renal Outcome in Patients with Diabetic Nephropathy: A Biopsy-Based Study

Objective: To explore the relationship between serum bilirubin concentration and clinicopathologic features and renal outcome in biopsy-diagnosed diabetic nephropathy (DN) in patients with type 2 diabetes mellitus.Methods: In this retrospective study, 118 patients with DN were enrolled. Participants were divided into two groups according to their median baseline serum bilirubin concentration: Group 1 (serum bilirubin ≤7.5 μmol /L); Group 2 (serum bilirubin >7.5 μmol /L). Basic clinical parameters were measured at the time of renal biopsy, and the relationships between serum bilirubin and the clinicopathologic features and renal outcome were analyzed.Results: Patients in Group 1 often had inferior renal function. Compared with Group 2, the glomerular classification and interstitial inflammation were more severe in subjects of Group 1, while arteriolar hyalinosis and interstitial fibrosis and tubular atrophy (IFTA) were comparable between the groups. Serum bilirubin was negatively correlated with the severity of the glomerular classification, interstitial inflammation, and IFTA. In the prognostic analysis, higher serum bilirubin level was associated with a lower risk of progression to end-stage renal disease, which was independent of the effects of age, gender, duration of diabetes, anemia, serum glucose, and hypertension but not of estimated glomerular filtration rate (hazard ratio, 0.406; 95% confidence interval, 0.074 to 2.225; P = .299).Conclusion: Our study showed a negative correlation between serum bilirubin level and renal pathologic lesions in patients with DN; serum bilirubin showed an inverse association with DN progression, but this was not independent.Abbreviations: CI = confidence interval; CKD = chronic kidney disease; DM = diabetes mellitus; DN = diabetic nephropathy; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; ESRD = end-stage renal disease; HbA1c = glycated hemoglobin; HO-1 = heme oxygenase 1; HR = hazard ratio; IFTA = interstitial fibrosis and tubular atrophy; log-BIL = log-transformed baseline serum bilirubin; T2DM = type 2 diabetes mellitus     

Clinicopathologic Features and Prognosis of Type 2 Diabetes Mellitus and Diabetic Nephropathy in Different Age Groups: More Attention to Younger Patients

Objective: Our study sought to investigate the clinicopathologic features and renal prognosis of patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) in different age groups.Methods: A total of 315 patients with T2DM and biopsy-proven DN were enrolled and divided into three groups by age: the Youth group (≤44 years old), the Middle-aged group (45 to 59 years old), and the Elderly group (≥60 years old).Results: The Youth group, Middle-aged group, and Elderly group accounted for 19.05% (60/315), 59.37% (187/315), and 21.59% (68/315) of the patients in our study, respectively. The patients in the Youth group had a higher estimated glomerular filtration rate (calculated using the Chronic Kidney Disease–Epidemiology collaboration formula) (P<.001), a higher incidence of diabetic retinopathy (P = .044), and a higher incidence of being in the lower-risk chronic kidney disease heat map category (P = .046) but lower duration of diabetes (P = .016). Histologically, patients in the Youth group had the highest incidence of glomerular classification in class I (P = .006) and arteriolar hyalinosis score of 0 (P = .005). The renal survival among the three groups was comparable (P>.05).Conclusion: This study indicated that there were different clinicopathologic features among Chinese DN patients in different age groups. Although the Youth group had a relatively lower rapid kidney disease progression rate, there were no significant differences in renal survival rate among the three groups, which calls more attention to early supervision and prevention for younger DN patients.Abbreviations: CKD = chronic kidney disease; DN = diabetic nephropathy; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; ESRD = end-stage renal disease; G&Y&O = green and yellow and orange; IFTA = interstitial fibrosis and tubular atrophy; T2DM = type 2 diabetes mellitus     

Diabetic Retinopathy,Classified Using the Lesion-Aware Deep Learning System,Predicts Diabetic End-Stage Renal Disease in Chinese Patients

Objective: To characterize the relationship between diabetic retinopathy (DR) and diabetic nephropathy (DN) in Chinese patients and to determine whether the severity of DR predicts end-stage renal disease (ESRD).Methods: Bilateral fundic photographs of 91 Chinese type 2 diabetic patients with biopsy-confirmed DN, not in ESRD stage, were obtained at the time of renal biopsy in this longitudinal study. The baseline severity of DR was determined using the Lesion-aware Deep Learning System (RetinalNET) in an open framework for deep learning and was graded using the Early Treatment Diabetic Retinopathy Study severity scale. Cox proportional hazard models were used to estimate the hazard ratio (HR) for the effect of the severity of diabetic retinopathy on ESRD.Results: During a median follow-up of 15 months, 25 patients progressed to ESRD. The severity of retinopathy at the time of biopsy was a prognostic factor for progression to ESRD (HR 2.18, 95% confidence interval 1.05 to 4.53, P = .04). At baseline, more severe retinopathy was associated with poor renal function, and more severe glomerular lesions. However, 30% of patients with mild retinopathy and severe glomerular lesions had higher low-density lipo-protein-cholesterol and more severe proteinuria than those with mild glomerular lesions. Additionally, 3% of patients with severe retinopathy and mild glomerular changes were more likely to have had diabetes a long time than those with severe glomerular lesions.Conclusion: Although the severity of DR predicted diabetic ESRD in patients with type 2 diabetes mellitus and DN, the severities of DR and DN were not always consistent, especially in patients with mild retinopathy or microalbuminuria.Abbreviations: CI = confidence interval; DM = diabetic mellitus; DN = diabetic nephropathy; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; ESRD = end-stage renal disease; HbA1c = hemoglobin A1c; HR = hazard ratio; NPDR = nonproliferative diabetic retinopathy; PDR = proliferative diabetic retinopathy; SBP = systolic blood pressure; T2DM = type 2 diabetes mellitus; VEGF = vascular endothelial growth factor     

Association between testosterone, estradiol and sex hormone binding globulin levels in men with type 1 diabetes with nephropathy

Male sex is a risk factor for development and progression of diabetic nephropathy; however, the relationship between sex hormone levels and diabetic nephropathy in type 1 diabetic men is unknown. This was a prospective follow-up study as part of the nationwide Finnish Diabetic Nephropathy (FinnDiane) Study; 297 patients were followed for 5.9 ± 1.5 years. Serum total testosterone (Tt) and estradiol (Te), calculated free testosterone (cFt) and estradiol (cFe) and sex hormone binding globulin were measured at baseline and correlated with urinary albumin excretion rate, estimated glomerular filtration rate and markers of metabolic syndrome. Diabetes without renal disease was associated with decreased Tt (p < 0.001), Te (p < 0.001) and cFt (p = 0.001) levels compared with healthy non-diabetic men. With progression of renal disease from micro- to macroalbuminuria, this decrease in serum Tt was even more pronounced. Cox regression showed that cFt and cFe were independent predictors of the progression from macroalbuminuria to end-stage renal disease. Our study shows that men with type 1 diabetes exhibit dysregulated sex hormone levels, which is most pronounced in men with progressive renal disease, suggesting that sex hormones may play a role in the pathogenesis of diabetic nephropathy associated with type 1 diabetes.     

Estrogen receptors in the kidney: Lessons from genetically altered mice

Background: Sex differences in human and animal models of kidney disease suggest that estrogen receptor (ER)-mediated events may modulate these processes. Genetically altered mice lacking one or both ERs provide a powerful tool to study these phenomena.Objective: This article examines sex differences in the kidney, particularly the role of ERs.Methods: To identify pertinent studies in genetically altered mice, a literature search was conducted on the MEDLINE database from January 1966 to July 2007, using the search terms estrogen receptor, kidney, and mice. Our group examined the effect of the ER-α knockout genotype on the kidney in streptozotocin-induced diabetes mellitus and compensatory kidney growth after uninephrectomy.Results: Female mice lacking ERa had reduced renal growth, including glomerular enlargement after 2 weeks of streptozotocin-induced diabetes mellitus and compensatory kidney growth 48 hours after uninephrectomy.Conclusion: ER-mediated events influence kidney growth and disease in female mice.     

Sex differences in the fetal programming of hypertension

Background: Numerous clinical and experimental studies support the hypothesis that the intrauterine environment is an important determinant of cardiovascular disease and hypertension.Objective: This review examined the mechanisms linking an adverse fetal environment and increased risk for chronic disease in adulthood with an emphasis on gender differences and the role of sex hormones in mediating sexual dimorphism in response to a suboptimal fetal environment.Methods: This review focuses on current findings from the PubMed database regarding animal models of fetal programming of hypertension, sex differences in phenotypic outcomes, and potential mechanisms in offspring of mothers exposed to an adverse insult during gestation. For the years 1988 to 2007, the database was searched using the following terms: fetal programming, intrauterine growth restriction, low birth weight, sex differences, estradiol, testosterone, high blood pressure, and hypertension.Results: The mechanisms involved in the fetal programming of adult disease are multifactorial and include alterations in the regulatory systems affecting the long-tterm control of arterial pressure. Sex differences have been observed in animal models of fetal programming, and recent studies suggest that sex hormones may modulate activity of regulatory systems, leading to a lower incidence of hypertension and vascular dysfunction in females compared with males.Conclusions: Animal models of fetal programming provide critical support for the inverse relationship between birth weight and blood pressure. Experimental models demonstrate that sex differences are observed in the pathophysiologic response to an adverse fetal environment. A role for sex hormone involvement is strongly suggested,with modulation of the renin-angiotensin system as a possible mechanism.     

Female protection in progressive renal disease is associated with estradiol attenuation of superoxide production

Background: Several types of renal disease progress at a faster rate in men compared with women, but the reasons for this sex difference are not well understood. Chronic renal disease is associated with elevated levels of toxic reactive oxygen species (ROS). Superoxide, the major ROS in the kidney, is generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase.Objective: To determine if female protection from renal disease progression is consistent with 17β-estradiol (E₂) attenuation of superoxide production, this study was conducted to assess superoxide production in the renal cortex of male and female control and renal wrap (RW) rats, as well as in ovariectomized rats treated with vehicle or E₂.Methods: Sprague-Dawley rats were divided into 2 sham operation male (Sham-M) and female (Sham-F) control groups, and 4 RW hypertensive groups: RW-M; RW-F; RW ovariectomized females treated with vehicle (RW-OVX); and RW ovariectomized females treated with E₂, supplied as a 0.24 mg/60-day release pellet (RW-OVX+E₂). All groups were maintained on a high-sodium (4% NaCl) diet for 6 weeks.Results: Mean (SEM) markers of renal injury and oxidative stress, including urinary protein (mg/24 h: RW-M, 298 [31] vs RW-F, 169 [22]; P < 0.001), microalbuminuria (RW/Sham arbitrary units [AU]/24 h: M, 8.78 [0.58] vs F, 4.31 [1.0]; P < 0.005), and malondialdehyde (nmol/24 h: RW-M, 167 [23] vs RW-F, 117 [8.5]; P < 0.05) levels, as well as mean glomerular volume (μm³ × 10⁶: RW-M, 2.25 [0.16] vs RW-F, 1.25 [0.04]; P < 0.001) and the glomerulosclerotic index (AU: RW-M, 2.64 [0.19] vs RW-F, 1.10 [0.09]; P < 0.001) were greater in both control and RW males compared with females in the same treatment groups. Though RW surgery increased mean arterial pressure in both male and female rats, no sex difference was observed. Under these conditions, mean (SEM) renal cortical NADPH oxidase activity was 1.3-fold higher in RW males compared with RW females (relative light units [RLU]/180 sec: RW-M, 4080 [240] vs RW-F, 3200 [260]; P < 0.05). Ovariectomy increased NADPH oxidase activity by 1.4-fold (RLU/180 sec: RW-OVX, 4520 [184]; P < 0.01) under conditions in which the mean glomerular volume and glomerulosclerotic index were both increased by 1.5-fold, whereas E₂ replacement (RLU/180 sec: RW-OVX+E₂, 2745 [440]) prevented these effects. Furthermore, the effects on NADPH oxidase activity were mirrored by changes in the protein abundance of NADPH oxidase subunit p22P^phox.Conclusion: These results suggest that E₂ protects the female kidney in part by attenuating injury-induced increases in renal superoxide production.     

Fatty Kidney Disease: A New Renal And Endocrine Clinical Entity? Describing the Role of the Kidney in Obesity,Metabolic Syndrome,and Type 2 Diabetes

Objective: To determine whether fatty kidney disease deserves be designated as a distinct clinical entity similar to fatty liver disease.Methods: Analysis and interpretation of the literature in a novel conceptual framework.Results: The kidney contributes to hyperglycemia, hypertension, inflammatory cytokines, and thus to diabetes and metabolic syndrome. Fat accumulation in and around the kidney drives this process and contributes to progression of chronic kidney disease itself. Weight loss improves these complications of fatty kidney. Diagnosis currently must be inferred from comorbidities but ultimately should be made by imaging once the importance of fatty kidney disease is established, much like fatty liver disease.Conclusion: Fatty kidney disease merits designation as a specific clinical entity similar to fatty liver disease. Greater attention to this may help encourage research into ameliorating the negative consequences of fatty kidney disease and developing new therapies.Abbreviations: BP = blood pressure; CKD = chronic kidney disease; CT = computed tomography; ESRD = end-stage renal disease; FFA = free fatty acid; FKD = fatty kidney disease; GFR = glomerular filtration rate; MetS = metabolic syndrome; MRI = magnetic resonance imaging; NAFLD = nonalcoholic fatty liver disease; RAAS = renin-angiotensin system; SGLT2 = sodium-glucose cotransporter 2; SNS = sympathetic nervous system; T2D = type 2 diabetes; TG = triglyceride     

Effects of gender on response to treatment with rivastigmine in mild cognitive impairment: A post hoc statistical modeling approach

Background: Epidemiologic studies have identified several demographic factors, including gender, that may influence the progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD).Objective: This analysis aimed to develop a sensitive model for detecting treatment benefits in patients with MCI by controlling for factors that predict progression to AD. The study used this statistical modeling to investigate the effect of gender on treatment response in patients with MCI.Methods: This post hoc analysis used data from the InDDEx (Investigation in Delay to Diagnosis of Alzheimer's disease with Exelon) study, a long-term (3- to 4-year), multicenter, randomized, double-blind, placebo-controlled trial of rivastigmine 3- to 12-mg/d capsules in 1018 patients with MCI. Baseline variables that were significantly associated with progression to AD within the InDDEx study population were identified. A Cox proportional hazards multivariate regression model that adjusted for these predictive factors was applied to the overall study population and to the gender subgroups.Results: Of 31 baseline variables analyzed, 13 were found to be significantly associated with progression to AD in the overall population. After adjustment using the Cox proportional hazards regression model, rivastigmine was associated with a significantly lower risk for progression to AD compared with placebo in the overall population (1016 patients; hazard ratio [HR] = 0.747; P = 0.045). This effect of rivastigmine was evident in women (530 patients; HR = 0.676; P = 0.046) but not in men.Conclusions: In these patients with MCI, a significant decrease in the risk for progression to AD was found with rivastigmine over 3 to 4 years. The proportion of women whose disease progressed to AD was significantly lower in the rivastigmine group than the placebo group (P = 0.046). This effect was not found in men. These data suggest that prospectively adjusting for predictive factors could lead to a more accurate estimation of treatment benefits in future studies of MCI.     

Insulin-Like Growth Factor Binding Protein-4 as a Marker of Chronic Lupus Nephritis

Kidney biopsy remains the mainstay of Lupus Nephritis (LN) diagnosis and prognostication. The objective of this study is to identify non-invasive biomarkers that closely parallel renal pathology in LN. Previous reports have demonstrated that serum Insulin-like growth factor binding protein 4 (IGFBP-4) was increased in diabetic nephropathy in both animal models and patients. We proceeded to assess if IGFBP4 could be associated with LN. We performed ELISA using the serum of 86 patients with LN. Normal healthy adults (N = 23) and patients with other glomerular diseases (N = 20) served as controls. Compared to the healthy controls or other glomerular disease controls, serum IGFBP-4 levels were significantly higher in the patients with LN. Serum IGFBP-4 did not correlate well with systemic lupus erythematosus disease activity index (SLEDAI), renal SLEDAI or proteinuria, but it did correlate with estimated glomerular filtration rate (R = 0.609, P < 0.0001). Interestingly, in 18 patients with proliferative LN whose blood samples were obtained at the time of renal biopsy, serum IGFBP-4 levels correlated strongly with the chronicity index of renal pathology (R = 0.713, P < 0.001). IGFBP-4 emerges a potential marker of lupus nephritis, reflective of renal pathology chronicity changes.     

Soluble Tumor Necrosis Factor Receptor Type 1 Levels Exhibit A Stronger Association With Renal Outcomes Than Traditional Risk Factors in Chinese Subjects With Type 2 Diabetes Mellitus

Objective: Associations between albuminuria and renal outcomes are inconsistent in patients with type 2 diabetes (T2D). Soluble tumor necrosis factor receptor type 1 (sTNFR1) is involved in declined kidney function and poor renal outcomes but this has not been confirmed among Chinese T2D patients. This study aimed to examine the association of sTNFR1 and renal outcomes in a cohort of these patients.Methods: Two hundred and eighty-three Chinese T2D patients were enrolled in a prospective observational study which excluded individuals with estimated glomerular filtration rates (eGFR) <30 mL/min/1.73m². Composite renal outcomes included either or both a >30% decline in eGFR and worsening albuminuria from consecutive tests of blood/urine during a 3.5-year follow-up.Results: Higher sTNFR1 levels were associated with impaired renal outcomes. sTNFR1 levels of ≥979 pg/mL yielded the most sensitivity and specific predictions of renal outcomes according to the receiver operating curve (area under the curve 0.68, P<.001; sensitivity 78.3%, specificity 48.9%). Renal events occurred more frequently in subjects with sTNFR1 ≥979 pg/mL than in others (sTNFR1 <979 pg/mL; 29% versus 10%; P<.001 by log-rank test). The association between sTNFR1 ≥979 pg/mL and renal outcomes remained significant after adjustment for relevant covariates (adjusted hazard ratio 2.43, 95% confidence interval 1.18 to 5.02; P = .01) and consistent across subgroups stratified by age, sex, blood pressure, eGFR, albuminuria, and the use of renin-angiotensin system inhibitors.Conclusion: Increased sTNFR1 levels were associated with renal outcomes in Chinese T2D subjects, making sTNFR1 a potential biomarker in diabetic kidney disease.     

Cross sectional longitudinal study of spot morning urine protein:creatinine ratio, 24 hour urine protein excretion rate,glomerular filtration rate,and end stage renal failure in chronic renal disease in patients without diabetes.

OBJECTIVE: To evaluate whether the protein:creatinine ratio in spot morning urine samples is a reliable indicator of 24 hour urinary protein excretion and predicts the rate of decline of glomerular filtration rate and progression to end stage renal failure in non-diabetic patients with chronic nephropathy. DESIGN: Cross sectional correlation between the ratio and urinary protein excretion rate. Univariate and multivariate analysis of baseline predictors, including the ratio and 24 hour urinary protein, of decline in glomerular filtration rate and end stage renal failure in the long term. SETTING: Research centre in Italy. SUBJECTS: 177 non-diabetic outpatients with chronic renal disease screened for participation in the ramipril efficacy in nephropathy study. MAIN OUTCOME MEASURES: Rate of decline in filtration rate evaluated by repeated measurements of unlabelled iohexol plasma clearance and rate of progression to renal failure. RESULTS: Protein:creatinine ratio was significantly correlated with absolute and log transformed 24 hour urinary protein values (P = 0.0001 and P < 0.0001, respectively.) Ratios also had high predictive value for rate of decline of the glomerular filtration rate (univariate P = 0.0003, multivariate P = 0.004) and end stage renal failure (P = 0.002 and P = 0.04). Baseline protein:creatinine ratios and rate of decline of the glomerular filtration rate were also significantly correlated (P < 0.0005). In the lowest third of the protein:creatinine ratio (< 1.7) there was 3% renal failure compared with 21.2% in the highest third (> 2.7) (P < 0.05). CONCLUSIONS: Protein:creatinine ratio in spot morning urine samples is a precise indicator of proteinuria and a reliable predictor of progression of disease in non-diabetic patients with chronic nephropathies and represents a simple and inexpensive procedure in establishing severity of renal disease and prognosis.     

Animal models of spontaneous diabetic kidney disease

Kidney disease, characterized by proteinuria and glomerular lesions, is a common complication of spontaneous diabetes mellitus in many animal species. It occurs in animals with hypoinsulinemia, hyperinsulinemia, or impaired glucose tolerance. The renal functional and structural abnormalities in spontaneously diabetic animals resemble human diabetic nephropathy in many respects. Mesangial expansion and glomerular basement membrane thickening, two structural hallmarks of diabetic glomerulopathy in humans, are the most frequently encountered lesions in animals. In addition, a nodular form of mesangial expansion that resembles but is not identical with human nodular glomerulosclerosis or the Kimmelstiel-Wilson lesion has been observed in some animal models. Other abnormalities, such as exudative hyaline lesions and arteriolar hyalinosis, have also been noted occasionally in other models. Although diabetic animals may develop kidney disease that resembles human diabetic nephropathy, no single animal model develops renal changes identical to those seen in humans. Nonetheless, animal models with spontaneous diabetic kidney disease may be useful for investigating the mechanisms of development of diabetic nephropathy and the effects of various treatment modalities on the progression of renal disease.     

Tinospora cordifolia activates PPARγ pathway and mitigates glomerular and tubular cell injury in diabetic kidney disease

Background: Diabetic Kidney Disease (DKD) is a common complication of diabetes and a leading cause of end-stage renal disease progression. Therefore, therapeutic strategies are desirable to mitigate the progression of disease into more severe consequences.Hypothesis/Purpose: Tinospora cordifolia is a traditionally known antidiabetic plant; however, its effect against DKD remains unexplored. Therefore, in the present study, we assessed the efficacy and mechanism of action of Tinospora cordifolia extract (TC) against DKD.Methods: The molecular interaction of the various phytoconstituents of TC with PPARγ were analyzed in silico. The effect of TC was studied on the viability, cell cycle, and gene expressions (PPARγ, TGFβ, and αSMA) in high glucose treated NRK-52E and SV40 MES13 cells. Further, streptozotocin-induced diabetic rats were treated with TC for eight weeks, and the effects on different biochemical, histological and molecular parameters were studied.Results: In silico analysis revealed the integration of various phytoconstituents of TC with PPARγ. It further increased PPARγ and decreased TGFβ and αSMA expressions in NRK-52E and SV40 MES13 cells. In diabetic rats, TC improved the fasting blood glucose, serum urea, and creatinine levels. It also lowered the urine microalbumin and advanced glycation end products (AGEs) levels. Histopathological studies revealed the preventive effect of TC on degenerative changes, mesangial proliferation and glomerular hypertrophy. Further, it reduced the inflammation and fibrotic changes in the kidney tissue estimated by various markers. The kidney tissue and gene expression analysis revealed the augmented levels of PPARγ after TC treatment.Conclusion: In conclusion, TC exerted the protective effect against DKD by inhibiting inflammation and fibrogenesis through the activation of PPARγ dependent pathways.     

Sex differences in progression of diabetic nephropathy in OVE26 type 1 diabetic mice

AimsOVE26 mice (FVB background), genetically overexpressing calmodulin in pancreatic beta cells, develop early onset type 1 diabetes, leading to progressive diabetic nephropathy (DN), with features of established human DN. The role of gender in characteristics of renal lesions has remained unexplored.MethodsMale and female OVE26 mice were compared to age and sex matched wild-type, nondiabetic FVB mice at ages of 4, 12, 24 and 36 weeks. Nephropathy was examined by measuring urine albumin-to-creatinine ratio, histopathology, expression of pathological markers and immunochemistry in the same cohort of mice.ResultsProgression of diabetic kidney disease was evident first in the OVE26 glomerulus, initially as mesangial matrix expansion at 4 weeks followed by loss of podocytes, glomerular volume expansion and severe albuminuria at 12 weeks. Tubule dilation and initiation of interstitial fibrosis did not become significant until 24 weeks. T-lymphocyte infiltration into the renal parenchyma appeared at 36 weeks. OVE26 female mice developed more advanced DN than male OVE26 mice, such as more severe albuminuria, greater podocyte loss, additional fibrosis and significantly more inflammatory cell infiltration. The female OVE26 mice had lowest level of plasma estradiol in all 36 weeks old mice, as well as renal estrogen receptors.ConclusionsThis demonstration of the role of gender, combined with the detailed characterization of DN progression illustrates the value of OVE26 mice for understanding gender effects on DN and provides the basis for researchers to better select the age and sex of OVE26 mice in future studies of type 1 DN.Research in contextWhat is already known about this subject?

• •OVE26 mice, genetically overexpressing calmodulin in pancreatic beta cells, develop early onset type 1 diabetes.
• •OVE26 mice are a widely used and valuable rodent model which develop severe, progressive diabetic nephropathy, with features of established human diabetic nephropathy.

What is the key question?

• •Does gender play a role in determining characteristics of renal lesions and severity of nephropathy?

What are the new findings?

• •Female OVE26 mice had more severe albuminuria, greater podocyte loss.
• •Female OVE26 mice had additional fibrosis and significantly more inflammatory cell infiltration.
• •Diabetes induced reductions in estradiol levels and renal estrogen receptors may be responsible for the female sensitization to DN in OVE26 mice.

How might this impact on clinical practice in the foreseeable future?

• •Our findings provide the basis for researchers to better select the age and sex of OVE26 mice in future studies of type 1 DN.

     

CS-886, a new angiotensin II type 1 receptor antagonist,ameliorates glomerular anionic site loss and prevents progression of diabetic nephropathy in Otsuka Long-Evans Tokushima fatty rats

BACKGROUND: Diabetic nephropathy is a leading cause of end-stage renal disease in industrialized countries. Previous studies have documented that angiotensin converting enzyme (ACE) inhibitors consistently reduce albuminuria and retard the progression of diabetic nephropathy. However, the involvement of angiotensin II in diabetic nephropathy is not fully understood. MATERIALS AND METHODS: In this study we compared the effects of CS-866, a new angiotensin II type 1 receptor antagonist, to that of an ACE inhibitor, temocapril hydrochloride, on the development and progression of diabetic nephropathy using Otsuka Long-Evans Tokushima fatty rats, a type II diabetes mellitus model animal. RESULTS: High doses of CS-866 or temocapril treatment were found to significantly improve urinary protein and beta(2)-microglobulin excretions in diabetic rats. In electron microscopic analysis, loss of glomerular anionic sites, one of the causes of glomerular hyperpermeability in diabetic nephropathy, was found to be significantly prevented by CS-866 treatment. Light microscopic examinations revealed that both treatments ameliorated glomerular sclerosis and tubulointerstitial injury in diabetic rats. Furthermore, high doses of CS-866 or temocapril treatment significantly reduced the positive stainings for transforming growth factor-beta (TGF-beta), vascular endothelial growth factor, and type IV collagen in glomeruli of diabetic rats. CONCLUSIONS: These results indicate that intrarenal angiotensin II type 1 receptor activation plays a dominant role in the development and progression of diabetic nephropathy. Our study suggests that CS-866 represents a valuable new drug for the treatment of diabetic patients with nephropathy.     

Osthole Mitigates Progressive IgA Nephropathy by Inhibiting Reactive Oxygen Species Generation and NF-κB/NLRP3 Pathway

Renal reactive oxygen species (ROS) and mononuclear leukocyte infiltration are involved in the progressive stage (exacerbation) of IgA nephropathy (IgAN), which is characterized by glomerular proliferation and renal inflammation. The identification of the mechanism responsible for this critical stage of IgAN and the development of a therapeutic strategy remain a challenge. Osthole is a pure compound isolated from Cnidiummonnieri (L.) Cusson seeds, which are used as a traditional Chinese medicine, and is anti-inflammatory, anti-apoptotic, and anti-fibrotic both in vitro and in vivo. Recently, we showed that osthole acts as an anti-inflammatory agent by reducing nuclear factor-kappa B (NF-κB) activation in and ROS release by activated macrophages. In this study, we examined whether osthole could prevent the progression of IgAN using a progressive IgAN (Prg-IgAN) model in mice. Our results showed that osthole administration resulted in prevention of albuminuria, improved renal function, and blocking of renal progressive lesions, including glomerular proliferation, glomerular sclerosis, and periglomerular mononuclear leukocyte infiltration. These findings were associated with (1) reduced renal superoxide anion levels and increased Nrf2 nuclear translocation, (2) inhibited renal activation of NF-κB and the NLRP3 inflammasome, (3) decreased renal MCP-1 expression and mononuclear leukocyte infiltration, (4) inhibited ROS production and NLRP3 inflammasome activation in cultured, activated macrophages, and (5) inhibited ROS production and MCP-1 protein levels in cultured, activated mesangial cells. The results suggest that osthole exerts its reno-protective effects on the progression of IgAN by inhibiting ROS production and activation of NF-κB and the NLRP3 inflammasome in the kidney. Our data also confirm that ROS generation and activation of NF-κB and the NLRP3 inflammasome are crucial mechanistic events involved in the progression of the renal disorder.