Glomerular Hypertrophy Research Articles

Renal protection induced by physical exercise may be mediated by the irisin/AMPK axis in diabetic nephropathy

In patients with diabetes, it has been suggested that physical exercise may reduce albuminuria and the progression of renal disease. However, the molecular mechanism by which physical exercise protects the kidney in diabetes remains poorly understood. The aim of the present study was to determine the contribution of muscle irisin secretion induced by aerobic physical exercise with the subsequent activation of AMPK for kidney protection under diabetic conditions. Aerobic physical exercise in rats protected the kidney in streptozotocin-induced diabetes. It reduced albuminuria, glomerular hypertrophy, and glomerular expression of collagen IV and fibronectin, as well as markers of kidney inflammation, when compared to sedentary diabetic rats. These effects were associated with elevation in muscle FNDC5/irisin and activity of AMPK in the diabetic kidney. However, the beneficial effects of exercise were lost when the diabetic rats were treated with CycloRGDyK, that in the bone it has been described as an irisin receptor blocker. In cultured human tubular (HK-2) cells, treatment with recombinant irisin counteracted the effect of high glucose in a dose-dependent manner. Irisin, per se, also activated AMPK in HK-2 cells. It is concluded that in diabetes, the renal protective effect of exercise may be mediated by the irisin/AMPK pathway.

Influence of carnosine and carnosinase-1 on diabetes-induced afferent arteriole vasodilation: implications for glomerular hemodynamics.

Dysregulation in glomerular hemodynamics favors hyperfiltration in diabetic kidney disease (DKD). Although carnosine supplementation ameliorates features of DKD, its effect on glomerular vasoregulation is not known. We assessed the influence of carnosine and carnosinase-1 (CN1) on afferent glomerular arteriole vasodilation and its association with glomerular size, hypertrophy, and nephrin expression in diabetic BTBRob/ob mice. Two cohorts of mice including appropriate controls were studied: i.e., diabetic mice that received oral carnosine supplementation (cohort 1) and human (h)CN1 transgenic (TG) diabetic mice (cohort 2). The lumen area ratio (LAR) of the afferent arterioles and glomerular parameters were measured by conventional histology. Three-dimensional analysis using a tissue clearing strategy was also used. In both cohorts, LAR was significantly larger in diabetic BTBRob/ob versus nondiabetic BTBRwt/ob mice (0.41 ± 0.05 vs. 0.26 ± 0.07, P < 0.0001 and 0.42 ± 0.06 vs. 0.29 ± 0.04, P < 0.0001) and associated with glomerular size (cohort 1: r = 0.55, P = 0.001 and cohort 2: r = 0.89, P < 0.0001). LAR was partially normalized by oral carnosine supplementation (0.34 ± 0.05 vs. 0.41 ± 0.05, P = 0.004) but did not differ between hCN1 TG and wild-type BTBRob/ob mice. In hCN1 TG mice, serum CN1 concentrations correlated with LAR (r = 0.90, P = 0.006). Diabetic mice displayed decreased nephrin expression and increased glomerular hypertrophy. This was not significantly different in hCN1 TG BTBRob/ob mice (P = 0.06 and P = 0.08, respectively). In conclusion, carnosine and CN1 may affect intraglomerular pressure in an opposing manner through the regulation of afferent arteriolar tone. This study corroborates previous findings on the role of carnosine in the progression of DKD.NEW & NOTEWORTHY Dysregulation in glomerular hemodynamics favors hyperfiltration in diabetic kidney disease (DKD). Although carnosine supplementation ameliorates features of DKD, its effect on glomerular vasoregulation is not known. We assessed the influence of carnosine and carnosinase-1 (CN1) on afferent glomerular arteriole vasodilation and its association with glomerular size, hypertrophy, and nephrin expression in diabetic BTBRob/ob mice. Our results provide evidence that carnosine feeding and CN1 overexpression likely affect intraglomerular pressure through vasoregulation of the afferent arteriole.

Klotho-derived peptide 6 ameliorates diabetic kidney disease by targeting Wnt/β-catenin signaling

Diabetic kidney disease (DKD) is one of the most common and devastating complications of diabetic mellitus, and its prevalence is rising worldwide. Klotho, an anti-aging protein, is kidney protective in DKD. However, its large size, prohibitive cost and structural complexity hamper its potential utility in clinics. Here we report that Klotho-derived peptide 6 (KP6) mimics Klotho function and ameliorates DKD. In either an accelerated model of DKD induced by streptozotocin and advanced oxidation protein products in unilateral nephrectomized mice or db/db mice genetically prone to diabetes, chronic infusion of KP6 reversed established proteinuria, attenuated glomerular hypertrophy, mitigated podocyte damage, and ameliorated glomerulosclerosis and interstitial fibrotic lesions, but did not affect serum phosphorus and calcium levels. KP6 inhibited β-catenin activation invivo and blocked the expression of its downstream target genes in glomerular podocytes and tubular epithelial cells. Invitro, KP6 prevented podocyte injury and inhibited β-catenin activation induced by high glucose without affecting Wnt expression. Co-immunoprecipitation revealed that KP6 bound to Wnt ligands and disrupted the engagement of Wnts with low density lipoprotein receptor-related protein 6, thereby interrupting Wnt/β-catenin signaling. Mutated KP6 with a scrambled amino acid sequence failed to bind Wnts and did not alleviate DKD in db/db mice. Thus, our studies identified KP6 as a novel Klotho-derived peptide that ameliorated DKD by blocking Wnt/β-catenin. Hence, our findings also suggest a new therapeutic strategy for the treatment of patients with DKD.

Antioxidation and Nrf2-mediated heme oxygenase-1 activation contribute to renal protective effects of hydralazine in diabetic nephropathy

Reactive oxygen species (ROS) and oxidative stress are associated with the progression of diabetic nephropathy (DN). Hydralazine is an antihypertensive agent and may act as a xanthine oxidase (XO) inhibitor to reduce uric acid levels in a mouse renal injury model. This study aimed to investigate the potential mechanisms of hydralazine in experimental DN. Streptozotocin-induced diabetic mice were fed a high-fat diet to generate DN. Human renal proximal tubular epithelial cells were used in vitro. Nitrendipine and allopurinol which can reduce blood pressure or XO activity levels, were used as two positive controls. Hydralazine downregulated NF-κB/p38 signaling pathways and reduced TNF-α/IL-6 expressions in high glucose-stimulated renal proximal tubular epithelial cells. Hydralazine reduced in vitro ROS production via XO inhibition and nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated heme oxygenase (HO)-1 activation. Furthermore, hydralazine reduced high glucose-induced apoptosis by downregulating PARP/caspase-3 signaling. Hydralazine and allopurinol but not nitrendipine reduced serum uric acid levels and systemic inflammation. Hydralazine and allopurinol treatment improved renal function with decreased urinary albumin-to-creatinine ratios, glomerular hypertrophy, glomerulosclerosis, and fibrosis in the kidney of DN mice. While both hydralazine and allopurinol downregulated XO and NADPH oxidase expression, only hydralazine upregulated Nrf2/HO-1 renal expression, suggesting the additional effects of hydralazine independent of XO/ NADPH oxidase inhibition. In conclusion, hydralazine protected renal proximal tubular epithelial cells against the insults of high glucose and prevented renal damage via XO/NADPH oxidase inhibition and Nrf-2/HO-1 activation, suggesting the comprehensive antioxidation and anti-inflammation mechanisms for the management of DN.

Increased activity of the metalloproteinase PAPP-A promotes diabetes-induced glomerular hypertrophy

BackgroundDiabetic nephropathy (DN) is a serious complication of diabetes and a common cause of end stage renal failure. Insulin-like growth factor (IGF)-signaling has been implicated in DN, but is mechanistically poorly understood. Here, we assessed the activity of the metalloproteinase PAPP-A, an activator of IGF activity, and its possible interaction with the endogenous PAPP-A inhibitors stanniocalcin (STC)-1 and -2 in the mammalian kidney under normal and hyperglycemic conditions. Methods and resultsImmunohistochemistry demonstrated that PAPP-A, its proteolytic substrate IGF binding protein-4, STC1 and STC2 are present in the human kidney. Endogenous inhibited complexes of PAPP-A (PAPP-A:STC1 and PAPP-A:STC2) were demonstrated in media conditioned by human mesangial cells (HMCs), suggesting that PAPP-A activity is regulated by the STCs in kidney tissue. A method for the selective detection of active PAPP-A in tissue was developed and a significant increase in glomerular active PAPP-A in human diabetic kidney relative to normal was observed. In DN patients, the estimated glomerular filtration rate correlated with PAPP-A activity. In diabetic mice, glomerular growth was reduced when PAPP-A activity was antagonized by adeno-associated virus-mediated overexpression of STC2. ConclusionWe propose that PAPP-A activity in renal tissue is precisely balanced by STC1 and STC2. An imbalance in this equilibrium causing increased PAPP-A enzymatic activity potentially contributes to the development of DN, and thus, therapeutic targeting of PAPP-A activity may represent a novel strategy for its treatment.

MO962: C-Peptide and Epicardial Adipose Tissue in Chronic Kidney Disease

Abstract BACKGROUND AND AIMS Recent studies suggest that C-peptide (CP) may exhibit characteristics of a hormone and show physiological functions in various tissues. Moreover, it has been proposed that CP could be involved in the regulation of lipolysis, adiponectin release and function of mesenchymal stem cells in adipose tissue. However, there is a certain controversy regarding reported effects of the CP. Its beneficial effects have been demonstrated in long-term complication in type 1 diabetes mellitus (T1DM). Substitution of CP in T1DM improves glomerular hyperfiltration, hypertrophy and proteinuria. In contrast to this, CP in T2DM shows proinflammatory and proatherogenic effects. The aim of this study was to find the association between CP, epicardial adipose tissue (EAT) and vascular calcifications in diabetic subjects under insulin treatment on dialysis. METHOD This is a retrospective study of 62 consecutive chronic kidney disease (CKD) stages 5D patients awaiting kidney transplantation referred for risk stratification. Computer tomography (CT) was used to assess quantify coronary artery calcium (CAC) and to measure EAT volume. CAC was considered present if a minimum of three contiguous pixels with an attenuation of ≥130 Hounsfield Units (HU) were detected along the course of a coronary artery. CAC scores were calculated using the method described by Agatston. EAT was identified as a hypodense area surrounding the myocardium and limited by pericardium. The pericardium was traced manually from the mid-left atrium to the left ventricular apex interpolating slices of 10 mm thickness; the application of an attenuation threshold in the range of -250 to -30 HU effectively excluded myocardium, coronary arteries, coronary calcium, aorta and blood pool, leaving in evidence the EAT alone. Demographic and anthropometrics data were collected on all patients through record review. RESULTS Demographic, clinical and laboratorial characteristics of patients enrolled in the study are resume in the Table 1. Young women and smoking were more prevalent; none of the analytical parameters were correlated with CP. Subjects with higher BMI exhibited higher levels of CP (P 0.03). EAT was strongly correlated with higher levels of CP (P 0.03). EAT was significantly correlated with severity of CAC scores (P 0.01). No correlation was found between CP and CAC. CONCLUSION As a marker of insulin reserve, CP can be used to evaluate insulin needs and overdose in dialysis patients and to avoid its lipogenic effects. New and novel hypoglycemic therapies may help in this issue. While EAT was correlated to CP, this was not associated with vascular calcification (CAC); this final observation may be related to the lower levels of vascular damage observed in CKD patients from kidney transplantation waiting list. More studies are needed to explore this association and utility.

Clinicopathological characteristics of high-altitude polycythemia-related kidney disease in Tibetan inhabitants

High-altitude polycythemia (HAPC) is a clinical syndrome that occurs in native inhabitants or long-term residents living at altitude. The kidney is one of the most affected organs. However, the clinical and kidney histopathological profiles of HAPC-related kidney disease have rarely been reported. Here, we report kidney biopsy-based clinicopathological study on this disease. HAPC was defined as excessive erythrocytosis [females, hemoglobin 190 g/L or more; males, 210 g/L or more] in patients living above an altitude of 2500 m for more than ten years. A total of 416 Tibetan patients underwent kidney biopsy between January 1, 2016, and November 31, 2020. Of these patients 17 met the diagnostic criteria for HAPC-related kidney disease. Clinically, these patients had a median urinary protein level of 2.5 g/24-hour (range 1.81-6.85). Twelve patients had hyperuricemia, nine had hypertension, and three had kidney insufficiency. On histopathology, glomerular hypertrophy, glomerular basement membrane thickening, podocyte foot process effacement, segmental glomerulosclerosis and global glomerulosclerosis were the main features. Extraglomerular arterial/arteriolar lesions were common, presenting as intimal fibrosis, hyalinosis and endothelial cell swelling/subintimal edema. Expansion of the arterial/arteriolar medial wall area characterized by smooth muscle cell proliferation was clearly observed, potentially indicating vascular remodeling. Hypoxia-inducible factor 2α was expressed in the kidney tissues of these patients. Thus, the pathological changes of HAPC-related kidney disease encompassed both glomerular and extraglomerular vascular lesions, suggesting a key role of both chronic hypoxia itself and secondary hemodynamic changes in the pathogenesis of this disease.

Abstract 500: Silencing Apolipoprotein C3 Prevents Diabetic Kidney Disease And Atherosclerosis In A Mouse Model Of Type 2 Diabetes

Diabetes increases the risk of both cardiovascular disease and kidney disease. Notably, most of the excess cardiovascular risk in people with diabetes is in those with kidney disease. Apolipoprotein C3 (APOC3) is a small apolipoprotein that is elevated by insulin-insufficiency and regulates plasma triglyceride levels. To test if APOC3, and the dyslipidemia it represents, play a role in diabetic kidney disease (DKD) and associated atherosclerosis, we treated BTBR wildtype (WT) and leptin-deficient (OB; diabetic) mice with an antisense oligonucleotide (ASO) to APOC3 or a control ASO (cASO), all in the setting of human-like dyslipidemia (accomplished by administration of an ASO targeting the LDLR). APOC3 ASO treatment reduced triglycerides, triglyceride-rich lipoproteins. It prevented diabetes-accelerated atherosclerosis in the aortic sinus, brachiocephalic artery, and aorta (sinus lesion: 67926 ± 8486 μm 2 lesion in cASO-treated OB mice compared to 38589 ± 9507 μm 2 in APOC3 ASO-treated OB mice, p&lt;0.05, n=12-15). The reduction in lesion size with APOC3 treatment was associated with fewer macrophages and reduced perilipin 2 staining (a marker for lipid droplet formation). In the kidney, diabetes resulted in a dramatic increase in glomerular hypertrophy, neutral lipid accumulation, APOC3, and APOE-accumulation, which APOC3 ASO-treatment attenuated. Furthermore, diabetes resulted in monocyte recruitment, macrophage accumulation, and macrophage lipid loading in the glomeruli, all of which was dramatically suppressed in the setting of APOC3 silencing (36% of glomerular macrophages were lipid loaded in OB cASO mice whereas only 9% were lipid loaded in APOC3-ASO treated mice, p&lt;0.0001). The recruitment was driven by increased endothelial cell ICAM1 expression, but monocyte lipid loading may also contribute. Intriguingly, APOC3-ASO treatment reduced diabetes-associated urinary albumin creatinine ratio but did not affect it in non-diabetic mice (WT mice: 374 ± 71 μg albumin/mg creatinine, OB cASO mice: 4648 ± 1021 μg/mg and OB mice with APOC3 ASO: 2341 ± 439 μg/mg, p&lt;0.05, n=12-14). Together, this suggests that targeting APOC3 and diabetic dyslipidemia might be beneficial for both diabetes-accelerated atherosclerosis and kidney disease.

Lack of Xdh Leads to Alterations in Renin‐Angiotensin‐Aldosterone System and Kidney Injury

Uric acid (UA) homeostasis has been elucidated as a key player in chronic kidney disease and cardiovascular diseases, yet definitive mechanisms are unknown. Previous studies in rodents and humans have shown that increased levels of serum UA predict an activated intrarenal Renin‐Angiotensin‐Aldosterone System (RAAS). In hyperuricemic rats, nephropathy was reported with glomerular hypertrophy and interstitial inflammation accompanied by increased renal renin expression. To explore whether hypouricemia leads to RAAS changes and kidney damage, we utilized a novel rat model with genetic ablation of the Xdh gene in the Dahl salt‐sensitive rat background (SSXdh‐/‐). The Xdh gene encodes for the Xanthine Oxidoreductase enzyme group, which produces UA from xanthine and hypoxanthine. We have shown that the SSXdh‐/‐model is hypouricemic and has severe kidney damage. The SSXdh‐/‐ rats demonstrated significant kidney function decline (SSXdh+/+&amp; SSXdh‐/‐respectively, diuresis: 2.7 ± 0.9 &amp; 14.4 ± 5.1 ml; creatinine clearance: 0.51 ± 0.19 &amp; 0.12 ± 0.04 ml/min; and plasma Na+: 136 ± 1.8 &amp; 150 ± 3.7 mmol/l). Quantification of RAAS components was done using liquid chromatography‐tandem mass spectrometry. The comparison of plasma from SSXdh+/+vs SSXdh‐/‐rats revealed significantly lower levels of angiotensin I (650 ± 109, 178 ± 25 pmol/l), Ang II (583 ± 70, 171 ± 16 pmol/l), and renin (indirect measurements using Ang I + Ang II: 1233 ± 172, 349 ± 40 pmol/l). Aldosterone level was increased in SSXdh‐/‐rats (870 ± 115 vs. 4106 ± 1038 pmol/l). The aldosterone/ Ang II ratio was significantly increased in the homozygous rats suggesting enhanced adrenal function (2 ± 0.1, 25 ± 6.3). To further evaluate the contribution of RAAS and its downstream signaling mechanisms, we performed RNA‐Seq analysis on kidney cortex tissue, which showed a number of RAAS‐related genes being differentially expressed between the SSXdh+/+and SSXdh‐/‐ rats. In hypouricemic rats, there was an increase in expression levels of Ace, Ccl2, Fos, Map3k1, Ptger2,and Stat3,and a decrease of Agtr1a, Hsd11b1,and Renb. Therefore, our results show that lack of Xdh/UA leads to kidney injury and functional decline with substantial remodeling in RAAS.

Pathophysiological analysis of uninephrectomized db/db mice as a model of severe diabetic kidney disease.

Diabetic nephropathy, included in diabetic kidney disease (DKD), is the primary disease leading to end-stage renal disease (ESRD) or dialysis treatment, accounting for more than 40% of all patients with ESRD or receiving dialysis. Developing new therapeutics to prevent the transition to ESRD or dialysis treatment requires an understanding of the pathophysiology of DKD and an appropriate animal model for drug efficacy studies. In this study, we investigated the pathophysiology of diabetic kidney disease with type 2 diabetes in uninephrectomized db/db mice. In addition, the nephrectomized db /db mice from 10 weeks to 42 weeks were used to assess the efficacy of long-term administration of the angiotensin-II-receptor antagonist losartan. The blood and urinary biochemical parameters, main pharmacological endpoint of the losartan therapy, were periodically measured. And at the end, histopathological analysis was performed. Uninephrectomized db/db mice clearly developed obesity and hyperglycemia from young age. Furthermore, they showed renal pathophysiological changes, such as increased urinary albumin-creatinine ratio (UACR) (the peak value 3104 ± 986 in 40-week-old mice), glomerular hypertrophy and increased fibrotic areas in the tubulointerstitial tubules. The blood pressure in the losartan group was significantly low compared to the normotensive Vehicle group. However, as expected, Losartan suppressed the increase in UACR (829±500) indicating the medication was sufficient, but the histopathological abnormalities including tubular interstitial fibrosis did not improve. These results suggest that the uninephrectomized db/db mice are useful as an animal model of the severe DKD indicated by the comparison of the efficacy of losartan in this model with the efficacy of losartan in clinical practice.

Применение ксеногенного фракционированного протеомного секретома стволовых и прогениторных клеток при остром ишемическом повреждении почек в эксперименте

Introduction. Currently, the possibilities of cell therapy using stem cells for the correction of functional disorders of organs, including kidneys, are being widely investigated. The main mechanism of action of stem cells is considered to be the activation of cellular regeneration and the inhibition of apoptosis by the products of their secretion (secretome), which makes it necessary to study the mechanisms of action of the stem cells secretome. Aim of study. To study the relationship of the nephroprotective effect of the drug, which is a protein-peptide secretom of embryonic brain cells (SESC), with its effect on the regeneration of kidney cells damaged by ischemia and the activity of their apoptosis. Material and methods. Experiments were carried out on 40 mongrel male rats weighing 280-320 g. Acute kidney injury of varying severity was caused by removal of the right kidney and ischemia of the remaining left kidney for 60 minutes or 90 minutes (20 rats per group). In each of these groups, 10 rats were injected daily subcutaneously with SESC at a dose of 0.1 ml/kg (10 injections), and the other 10 rats were not treated. After 3, 7 and 14 days, the ischemic kidney was removed and subjected to histological examination and histochemical determination of the expression of the proliferation marker Ki-67 and the anti-apoptotic protein Bcl-2 in the kidney structures. Results. In the treatment of SESC, up to 20% of hypertrophied renal glomeruli were detected already on the 3rd day in the absence of glomeruli with glomerulosclerosis, whereas in control experiments at this time hypertrophied glomeruli were not detected, and the proportion of glomeruli with signs of glomerulosclerosis was 5-10%. On the 7th and 14th days in both groups, the proportion of hypertrophied glomeruli increased, being compared in the group with 60-minute ischemia, but maintaining higher values in experiments with 90-minute ischemia and SESC therapy compared with the control. Glomeruli with glomerulosclerosis were significantly less frequently detected in the treatment of SESC, regardless of the severity of ischemic damage. At the same time, the expression of Bcl-2 in renal glomerular cells during SESC therapy decreased significantly to a lesser extent than in control experiments, confirming the relationship of inhibition of apoptosis during SESC therapy with inhibition of the development of sclerotic processes. A significant increase in the number of epithelial cells expressing the proliferation marker Ki-67 on the 3rd day, followed by a gradual decrease in their number, was detected in the renal tubules during SESC therapy, whereas in the control an increase in the number of labeled cells occurred only on the 7th and 14th days. With an increase in the severity of ischemic damage, the proliferation-stimulating effect of SESC was prolonged up to 14 days. The proliferative effect of SESC therapy was accompanied by a decrease in damage to the renal tubules, and the percentage of tubules with necrotic epithelium progressively decreased from 3-5% to 0-1% with an increase in the period after the start of therapy (7 and 14 days), indicating epithelial regeneration, while in the control their proportion remained at a higher level. Conclusion. Stimulation of cell proliferation and inhibition of apoptosis of damaged cells play an essential role in the nephroprotective effect of SESC, as in stem cells.

Investigation of the effects of fetal rat kidney-derived mesenchymal stem cells implementation on doxorubicin-induced nephropathy in male Sprague–Dawley rats

The potential protective effects of mesenchymal stem cells (MSCs) on some kidney diseases have been reported. However, the effect of the fetal kidney–derived (FKD)MSCs on doxorubicin-induced nephropathy has not been studied yet. This study aimed to treat rats with doxorubicin-induced kidney injuries by transplantation of –FKD-MSCs. Twenty-four Sprague-Dawley rats were divided into three groups as control, doxorubicin nephropathy (Sham), and doxorubicin + MSC treated group. Serum biochemistry analysis was performed at the beginning and the end of the study. Functional changes in kidneys were evaluated by scintigraphy. In the doxorubicin nephropathy group, histopathological findings such as mesangial cell proliferation, tubular cast, and glomerular hypertrophy were observed, whereas in the MSC group these findings were significantly reduced. CD133 and CD24 positive immunoreactions were the most severe and frequently observed in the MSC group. While positive staining was detected in the tubular epithelium, there was no immunostaining observed in the glomerulus. The results showed that both functional and histological improvements were achieved in the MSC group compared to the Sham group. In conclusion, transplantation of fetal kidney - derived MSCs into patients with renal damage is thought to contribute to the healing of the renal tissue.

Steatosis is involved in the progression of kidney disease in a high-fat-diet-induced non-alcoholic steatohepatitis mouse model.

Chronic kidney disease (CKD) and non-alcoholic steatohepatitis (NASH) are major health issues associated with the metabolic syndrome. Although NASH is a known risk factor of CKD, the mechanisms linking these two diseases remain poorly understood. We aimed to investigate alterations in the kidney complicated with dyslipidemia in an established NASH mouse model. Male C57BL6/J mice were fed with control diet or high-fat diet (HFD), containing 40% fat, 22% fructose, and 2% cholesterol for 16 weeks. Metabolic characteristics, histological changes in the kidney, endoplasmic reticulum (ER) stress, apoptosis, and fibrosis were evaluated by histological analysis, immunoblotting, and quantitative reverse transcription-polymerase chain reaction. Levels of serum aspartate aminotransferase, alanine aminotransferase, alkali-phosphatase, total cholesterol, and urinary albumin were significantly higher in mice fed with HFD. Remarkable steatosis, glomerular hypertrophy, and interstitial fibrosis were also shown in in the kidney by leveraging HFD. Furthermore, HFD increased the mRNA expression levels of Casp3, Tgfb1, and Nfe2l2 and the protein level of BiP. We observed the early changes of CKD and speculate that the underlying mechanisms that link CKD and NASH are the induction of ER stress and apoptosis. Further, we observed the activation of Nfe2l2 in the steatosis-induced CKD mouse model. This NASH model holds implications in investigating the mechanisms linking dyslipidemia and CKD.

Retraction for Su et al., SHP-1 aggravates obesity-related glomerulopathy and palmitic acid-induced podocyte injury via regulating the PI3K/Nrf2/SIRT1 axis.

Obesity-related glomerulopathy (ORG) is described as obesity-driven glomerular hypertrophy. SHP-1 is associated with glomerular pathology. This study is designed to investigate the molecular mechanism of Src homology region 2 domain-containing protein tyrosine phosphatase 1 (SHP-1) in ORG and palmitic acid (PA)-induced podocyte injury. After analysis of clinical samples, an ORG mouse model was established via high-fat diet feeding, followed by detection of physiological and biochemical indexes, glomerular area, and inflammatory factor levels. In vitro cell model was established using (PA). Cell viability, apoptosis, and lipid deposition were determined. SHP-1, nuclear factor-erythroid 2-related factor 2 (Nrf2), phosphatidylinositol 3-kinase (PI3K), and sirtuin 1 (SIRT1) expressions were measured, and their binding relationships were testified. SHP-1 was highly expressed in ORG patients and was associated with renal function indexes. Silencing SHP-1 alleviated symptoms of ORG mice and PA-induced podocyte injury in vitro. SHP-1 bound to PI3K to inhibit PI3K phosphorylation and Nrf2 expression. Nrf2 bound to the SIRT1 promoter to promote SIRT1 transcription. Inhibition of Nrf2 or SIRT1 reversed the role of silencing SHP-1 in podocyte injury. Overall, SHP-1 was highly expressed in ORG and inhibited PI3K phosphorylation to block activation of Nrf2/SIRT1, thereby aggravating ORG-induced renal injury in vivo and PA-induced podocyte injury in vitro.

Autopsy study examining non-chronic kidney disease versus chronic kidney disease caused by hypertensive-nephrosclerosis in elderly subjects.

The aim of this autopsy study was to clarify the differences of renal histopathology between non-chronic kidney disease (CKD) and CKD caused by hypertensive-nephrosclerosis in the elderly and during the aging process. We examined autopsy specimens from 105 elderly patients (53 male subjects; mean age, 86.2years) including 44 patients with CKD as a result of nephrosclerosis. The analysis was divided into two groups depending on whether they had CKD. The incidences of arterial intimal thickening (AIT), obsolescent-type global glomerulosclerosis (OB), and interstitial fibrosis and tubular atrophy (IF/TA) were higher in the CKD group than in the non-CKD group (all p < 0.01). These factors were all correlated with each other (AIT vs. OB, r = 0.43; AIT vs. IF/TA, r = 0.25; OB vs. IF/TA, r = 0.53). IF/TA had the strongest association with hypertension and decreased eGFR. In the non-CKD group, the frequency of OB was more than 20% in subjects aged 90years or older. However, the individuals in the non-CKD group tended to have compensatory glomerular hypertrophy with increasing age and a retained eGFR, while the CKD group was unable to obtain compensatory hypertrophy and had a lower eGFR. We also found that AIT, OB and IF/TA occurred independently of systemic atherosclerosis. Non-CKD in the elderly refers to the so-called aging kidney. The progression from aging kidney to CKD caused by nephrosclerosis was influenced by increases in AIT, OB and IF/TA. IF/TA was thought to be the most important downstream factor in the progression of aging kidney to CKD.

POS-204 Analyze the Expression of mRNA m6A Methylation in Diabetic Nephropathy

Diabetic Nephropathy (DN) is a microvascular complication in patients with both type I and II diabetes with poorly glycemic control. It can ultimately lead to end-stage renal disease, accounting for 40% of patients requiring renal replacement therapy. DN is a chronic disease characterized by glomerular hypertrophy, proteinuria, decreased glomerular filtration, and renal fibrosis with loss of renal function caused by high glucose condition. The morphological and the ultrastructural changes in DN include progressive thickening of the glomerular basement membrane, expansion of the mesangial matrix, glomerular hyperfiltration, and tubulointerstitial fibrosis. DN can quickly progress to end-stage kidney disease without treatment because of no clinical symptoms in early stage. Hence, understanding the mechanism of the development of DN is extremely important for better treatment. Epigenetic dysregulation plays a critical role in the initiation and progression of DN, and post-transcriptional modifcations, such as RNA methylation, have attracted the attention of many researchers. There has been identified more than 170 RNA modifications in RNA. N6-methyladenosine (m6A) is the most abundant and widely distributed RNA modification of most eukaryotes. In addition, METTL3, METTL14, WTAP has been identified as a methyltransferase, while FTO and ALKBH5 have been identified as demethyltransferas. Recently m6A modification has been identified and emerging as an important role in RNA expression, RNA variable splicing, transport, stability and translation, mRNA stability and then influence the development of various diseases especially in cancers. However, the quantity, distribution, and functions of m6A in DN are still unclear. We performed human m6A mRNA & lncRNA Epitranscriptomic Microarray and in-depth bioinformatics analysis of m6A in mRNA and lncRNAs in human healthy kidney and DN puncture tissues. LC-MS Based mRNA modification detection were used to confirm the m6A methylation level. Data mining from the nephroseq database of WTAP level in DN tubulointerstitium and its relationship with kidney function. The results showed marked differences in the amount and distribution of m6A between these two type tissues. The number of m6A methylation genes in DN was much more than that in healthy tissues. Bioinformatics analysis showed that the two groups, with diferent methylation. Heatmap showing the m6A hypermethylation tendency in DN for 30 representative genes involved in 6 canonical DN-related pathways (PI3K–AKT, RAS,VEGF, Chemoking, Isuline and Renin-angiotensin system)(Figure 1). Agilent 6460 QQQ mass spectrometer with an Agilent 1260 HPLC system using Multi reaction monitored 20 types nucleotides with normalized peak area>1000. The ratio of m6A/A and 3’-Omel/I are significantly higher in DN patients than control(Figure 2). WTAP is highly expressed and associated with kidney function from the nephroseq database. Furthermore, there were also correlations of WTAP expression with serum creatinine and glomerular filtration (figure 3). Our findings suggest that m6A methylation in mRNA may be involved in the development of DN and that the methylase WTAP may be a major contributor.

Pdx1 Knockout Leads to a Diabetic Nephropathy- Like Phenotype in Zebrafish and Identifies Phosphatidylethanolamine as Metabolite Promoting Early Diabetic Kidney Damage.

The pdx1-/- zebrafish mutant was recently established as a novel animal model of diabetic retinopathy. In this study, we investigate whether knockout of pdx1 also leads to diabetic kidney disease (DKD). pdx1-/- larvae exhibit several signs of early DKD, such as glomerular hypertrophy, impairments in the filtration barrier corresponding to microalbuminuria, and glomerular basement membrane (GBM) thickening. Adult pdx1-/- mutants show progressive GBM thickening in comparison with the larval state. Heterozygous pdx1 knockout also leads to glomerular hypertrophy as initial establishment of DKD similar to the pdx1-/- larvae. RNA sequencing of adult pdx1+/- kidneys uncovered regulations in multiple expected diabetic pathways related to podocyte disruption and hinting at early vascular dysregulation without obvious morphological alterations. Metabolome analysis and pharmacological intervention experiments revealed the contribution of phosphatidylethanolamine in the early establishment of kidney damage. In conclusion, this study identified the pdx1 mutant as a novel model for the study of DKD, showing signs of the early disease progression already in the larval stage and several selective features of later DKD in adult mutants.

A Rationalized Overview of Diabetic Nephropathy

Diabetic nephropathy is a prime motive of end-level renal disease, and there was a non-stop boom in its occurrence global with inside the beyond decades. Diabetic nephropathy is characterized via way of means of microalbuminuria, renal and glomerular hypertrophy, mesangial growth with glomerular basement membrane thickening, arteriolar hyalinosis, and international glomerular sclerosis, which in the long run motive the development of proteinuria and renal failure. The time period diabetic kidney disease (DKD) is now normally used to embody the spectrum of human beings with diabetes who've both albuminuria and discounts in renal function. In this article, the medical presentation and method to prognosis of DKD might be discussed, as will its prognosis. The popular ideas of control of DKD can also be reviewed close to modern-day global guidelines. The present review deal with brief about DN pathophysiology, prevention measures along with treatment approaches.

Esculetin alleviates murine lupus nephritis by inhibiting complement activation and enhancing Nrf2 signaling pathway

Ethnopharmacological relevanceEsculetin is a bioactive compound of medicinal herb Hydrangea paniculata, and has showed anti-oxidation and anti-inflammation bioactivities. Renal local oxidative stress and inflammation are import contributors for progression of lupus nephritis (LN). Aim of the studyIn the present study, the renal protective effect of esculetin against LN was evaluated using MRL/lpr mice. Materials and methodsMRL/lpr mice were orally administrated with esculetin (20 mg/kg and 40 mg/kg) from 10 to 20 weeks and then renal function and kidney pathology were analyzed. ResultsEsculetin significantly attenuated renal impairment in MRL/lpr mice by reducing blood urea nitrogen (BUN), serum creatinine (Scr) and albuminuria, and ameliorated the glomerular hypertrophy, tubular interstitial fibrosis and mononuclear cell infiltration into interstitium. mRNA microarray suggested that esculetin could significantly down-regulate complement cascade, inflammation and fibrosis pathway, and up-regulate Nrf2-related anti-oxidation genes. Most surprising finding in the current study was that esculetin could inhibit the complement activation both in classical and alternative pathway using in vitro hemolysis assay, further enzyme assay suggested that esculetin blocked the C3 convertase (C4b2a) to exert this inhibitory capability. Molecular docking predicted that esculetin had four conventional hydrogen bonds interacting with C4b2a, and CDOCKER energy is relatively lower. Luciferase reporter gene demonstrated that esculetin could activate Nrf2 signaling pathway, and further flow cytometry confirmed that anti-oxidation bioactivity of esculetin was dependent on Nrf2 activation. On the other hand, esculetin could inhibit NFκB nuclear translocation and TGFβ-smad3 profibrosis pathway. ConclusionEsculetin shows beneficial effect on LN progression, and it may be a good natural leading compound for design of chemical compounds to treat LN.

Kidney Damage Caused by Obesity and Its Feasible Treatment Drugs.

The rapid growth of obesity worldwide has made it a major health problem, while the dramatic increase in the prevalence of obesity has had a significant impact on the magnitude of chronic kidney disease (CKD), especially in developing countries. A vast amount of researchers have reported a strong relationship between obesity and chronic kidney disease, and obesity can serve as an independent risk factor for kidney disease. The histological changes of kidneys in obesity-induced renal injury include glomerular or tubular hypertrophy, focal segmental glomerulosclerosis or bulbous sclerosis. Furthermore, inflammation, renal hemodynamic changes, insulin resistance and lipid metabolism disorders are all involved in the development and progression of obesity-induced nephropathy. However, there is no targeted treatment for obesity-related kidney disease. In this review, RAS inhibitors, SGLT2 inhibitors and melatonin would be presented to treat obesity-induced kidney injury. Furthermore, we concluded that melatonin can protect the kidney damage caused by obesity by inhibiting inflammation and oxidative stress, revealing its therapeutic potential.