Tangshen formula protects against podocyte apoptosis via enhancing the TFEB-mediated autophagy-lysosome pathway in diabetic nephropathy.

ETHNOPHARMACOLOGICAL RELEVANCE: Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease and currently there are no specific and effective drugs for its treatment. Podocyte injury is a detrimental feature and the major cause of albuminuria in DN. We previously reported Tangshen Formula (TSF), a Chinese herbal medicine, has shown therapeutic effects on DN. However, the underlying mechanisms remain obscure. AIM OF THE STUDY: This study aimed to explore the protective effect of TSF on podocyte apoptosis in DN and elucidate the potential mechanism. MATERIALS AND METHODS: The effects of TSF were assessed in a murine model using male KKAy diabetic mice, as well as in advanced glycation end products-stimulated primary mice podocytes. Transcription factor EB (TFEB) knockdown primary podocytes were employed for mechanistic studies. In vivo and in vitro studies were performed and results assessed using transmission electron microscopy, immunofluorescence staining, and western blotting. RESULTS: TSF treatment alleviated podocyte apoptosis and structural impairment, decreased albuminuria, and mitigated renal dysfunction in KKAy mice. Notably, TSF extracted twice showed a more significant reduction in proteinuria than TSF extracted three times. Accumulation of autophagic biomarkers p62 and LC3, and aberrant autophagic flux in podocytes of DN mice were significantly altered by TSF therapy. Consistent with the in vivo results, TSF prevented the apoptosis of primary podocytes exposed to AGEs and activated autophagy. However, the anti-apoptosis capacity of TSF was countered by the autophagy-lysosome inhibitor chloroquine. We found that TSF increased the nuclear translocation of TFEB in diabetic podocytes, and thus upregulated transcription of its several autophagic target genes. Pharmacological activation of TFEB by TSF accelerated the conversion of autophagosome to autolysosome and lysosomal biogenesis, further augmented autophagic flux. Conversely, TFEB knockdown negated the favorable effects of TSF on autophagy in AGEs-stimulated primary podocytes. CONCLUSIONS: These findings indicate TSF appears to attenuate podocyte apoptosis and promote autophagy in DN via the TFEB-mediated autophagy-lysosome system. Thus, TSF may be a therapeutic candidate for DN.

Klotho Supplementation Reverses Renal Dysfunction and Interstitial Fibrosis in Remnant Kidney.

INTRODUCTION: While recent investigations show that klotho exerts renoprotective actions, it has not been fully addressed whether klotho protein supplementation reverses renal damage. METHODS: The impacts of subcutaneous klotho supplementation on rats with subtotal nephrectomy were examined. Animals were divided into 3 groups: group 1 (short remnant [SR]): remnant kidney for 4 weeks, group 2 (long remnant [LR]): remnant kidney for 12 weeks, and group 3 (klotho supplementation [KL]): klotho protein (20 µg/kg/day) supplementation on the remnant kidney. Blood pressure, blood and urine compositions with conventional methods such as enzyme-linked immunosorbent assay and radioimmunoassay, kidney histology, and renal expressions of various genes were analyzed. In vitro studies were also performed to support in vivo findings. RESULTS: Klotho protein supplementation decreased albuminuria (-43%), systolic blood pressure (-16%), fibroblast growth factor (FGF) 23 (-51%) and serum phosphate levels (-19%), renal angiotensin II concentration (-43%), fibrosis index (-70%), renal expressions of collagen I (-55%), and transforming growth factor ß (-59%) (p < 0.05 for all). Klotho supplementation enhanced fractional excretion of phosphate (+45%), glomerular filtration rate (+76%), renal expressions of klotho (+148%), superoxide dismutase (+124%), and bone morphogenetic protein (BMP) 7 (+174%) (p < 0.05 for all). CONCLUSION: Our data indicated that klotho protein supplementation inactivated renal renin-angiotensin system, reducing blood pressure and albuminuria in remnant kidney. Furthermore, exogenous klotho protein supplementation elevated endogenous klotho expression to increase phosphate excretion with resultant reductions in FGF23 and serum phosphate. Finally, klotho supplementation reversed renal dysfunction and fibrosis in association with improved BMP7 in remnant kidney.

Ginsenoside Rb1 alleviates diabetic kidney podocyte injury by inhibiting aldose reductase activity.

Panax notoginseng, a traditional Chinese medicine, exerts beneficial effect on diabetic kidney disease (DKD), but its mechanism is not well clarified. In this study we investigated the effects of ginsenoside Rb1 (Rb1), the main active ingredients of Panax notoginseng, in alleviating podocyte injury in diabetic nephropathy and the underlying mechanisms. In cultured mouse podocyte cells, Rb1 (10 µM) significantly inhibited high glucose-induced cell apoptosis and mitochondrial injury. Furthermore, Rb1 treatment reversed high glucose-induced increases in Cyto c, Caspase 9 and mitochondrial regulatory protein NOX4, but did not affect the upregulated expression of aldose reductase (AR). Molecular docking analysis revealed that Rb1 could combine with AR and inhibited its activity. We compared the effects of Rb1 with eparestat, a known aldose reductase inhibitor, in high glucose-treated podocytes, and found that both alleviated high glucose-induced cell apoptosis and mitochondrial damage, and Rb1 was more effective in inhibiting apoptosis. In AR-overexpressing podocytes, Rb1 (10 µM) inhibited AR-mediated ROS overproduction and protected against high glucose-induced mitochondrial injury. In streptozotocin-induced DKD mice, administration of Rb1 (40 mg·kg-1·d-1, ig, for 7 weeks) significantly mitigated diabetic-induced glomerular injuries, such as glomerular hypertrophy and mesangial matrix expansion, and reduced the expression of apoptotic proteins. Collectively, Rb1 combines with AR to alleviate high glucose-induced podocyte apoptosis and mitochondrial damage, and effectively mitigates the progression of diabetic kidney disease.

Black mulberry fruit extract alleviates streptozotocin-induced diabetic nephropathy in rats: targeting TNF-α inflammatory pathway.

OBJECTIVES: This study was designed to investigate the effect of Morus nigra fruit extract in retarding the progression of diabetic nephropathy in streptozotocin (STZ)-induced diabetic rats. METHODS: Diabetic male Wistar rats were injected with black mulberry fruit extract (BMFE) at doses of 150 and 300 mg/kg body weight. After 4 weeks, microalbuminuria was estimated in addition to serum concentrations of glucose, insulin, creatinine and albumin. KEY FINDINGS: The study revealed a significant amelioration of all the measured parameters in diabetic animals. In addition, MDA, lipid peroxide levels and catalase activity were also improved. The histopathological examination of kidney tissues revealed significant improvement of the pathological changes and glomerular sclerosis in diabetic rats treated with BMFE. Treated rats showed downregulation of TNF-α, vascular cell adhesion molecule-1 (VCAM-1) and fibronectin mRNA expression. CONCLUSION: The ameliorative effect of BMFE on diabetic nephropathy is not only through its potent antioxidant and hypoglycaemic effects but also through its downregulation of TNF-α, VCAM-1 and fibronectin mRNA expression in renal tissues of diabetic-treated rats. Therefore, BMFE as dietary supplement could be a promising agent in improving diabetic nephropathy.

Metabolic Changes and Diabetes Microvascular Complications 5 Years After Obesity Surgery.

BACKGROUND: Obesity surgery has pronounced effects on metabolic profile of patients with type 2 diabetes mellitus (T2DM); however, reports on long-term remission rates based on the standardised and holistic criteria by the International Diabetes Federation (IDF) and effects on T2DM microvascular complications are scarce in the literature. In this retrospective clinical trial, our objectives were to assess these variables 5 years after surgery. METHODS: Clinical data and direct measurements of renal and retinal damage were collected prospectively and analysed retrospectively for 82 patients with T2DM who underwent obesity surgery and were followed up for 5 years. RESULTS: The cohort of 82 patients with T2DM that were followed up 5 years after obesity surgery was predominantly female (71%) with a median age of 51 years, weight of 133.5 kg, BMI of 46.8 kg/m2 and pre-operative duration of T2DM of 8 years; 6% of patients had diet-controlled T2DM, 57% were on non-insulin treatment and 37% were on insulin treatment pre-operatively. Of the total 82 patients, 59 patients underwent Roux-en-Y gastric bypass, 15 sleeve gastrectomy and 8 patients underwent gastric band operations. At 5 years, 5% and 15% patients achieved optimisation and improvement of the metabolic state based on the IDF criteria respectively. Surgery was associated with almost halving of the albumin-creatinine ratio in 22 patients with pre-existing albuminuria (follow-up data available for 64 patients) and an overall stabilisation of retinopathy in 24 patients with retinal images available at 5 years. CONCLUSION: Whilst the findings on microvascular complications are encouraging, the rates of metabolic remission were lower than expected and raise the need for validated protocols to assist clinicians in managing these patients more aggressively post-operatively to achieve optimum cardio-metabolic risk factor control and hopefully further reduction in microvascular and macrovascular complications.

Astragalus membranaceus and Panax notoginseng, the Novel Renoprotective Compound, Synergistically Protect against Podocyte Injury in Streptozotocin-Induced Diabetic Rats.

This study was aimed at investigating the synergistical protective effects of Astragalus membranaceus (AG) and Panax notoginseng (NG) on podocyte injury in diabetic rats. Diabetes was induced in rats by a single intraperitoneal injection of streptozotocin at 55 mg/kg. Diabetic rats were then orally administrated with losartan, AG, NG, and AG plus NG (2 : 1) for 12 weeks. Albuminuria, biochemical markers, renal histopathology, and podocyte number per glomerulus were measured. Podocyte apoptosis was determined by triple immunofluorescence labeling including TUNEL assay, WT1, and DAPI. Renal expression of nephrin, α-dystroglycan, Bax, Bcl-xl, and Nox4 was evaluated by immunohistochemistry, western blot, and RT-PCR. AG plus NG ameliorated albuminuria, renal histopathology, and podocyte foot process effacement to a greater degree than did AG or NG alone. The number of podocytes per glomerulus, as well as renal expression of nephrin, α-dystroglycan, and Bcl-xl, was decreased, while podocyte apoptosis, as well as renal expression of Bax and Nox4, was increased in diabetic rats. All of these abnormalities were partially restored by AG plus NG to a greater degree than did AG or NG alone. In conclusion, AG and NG synergistically ameliorated diabetic podocyte injury partly through upregulation of nephrin, α-dystroglycan, and Bcl-xl, as well as downregulation of Bax and Nox4. These findings might provide a novel treatment combination for DN.

Enhanced Therapeutic Potency of Nanoemulsified Garlic Oil Blend Towards Renal Abnormalities in Pre-diabetic Rats.

The therapeutic potency of ultrasonic nanoemulsified garlic oil blend using a non-ionic surfactant (Tween 80) was assessed on pre-diabetic Wistar rats with microalbuminuria. The pre-diabetic condition was induced in male albino Wistar rats by supplementing high-fat diet. The prolonged period of the pre-diabetic state caused renal dysfunctioning, which was indicated by microalbuminuria. Treatment of pre-diabetic rats with nanoemulsified garlic oil blend significantly ameliorated the lipid profile (p < 0.001), urinary albumin (p < 0.01), microprotein (p < 0.001), urinary triglycerides (p < 0.01), serum triglycerides (p < 0.01), serum albumin (p < 0.05), and protein levels (p < 0.01) in comparison to treatment of pre-diabetic rats with garlic oil blend or atorvastatin. Similarly, histopathological investigations indicated a remarkable attenuation in the mesangial expansion and proliferation, glomerular and tubular basement membrane thickening, and the tubular lipid deposits on administering nanoemulsified garlic oil blend than garlic oil blend or atorvastatin. Moreover, nanoemulsified garlic oil blend significantly promoted renal podocin gene expression by 3.98-fold (p < 0.001) and attenuated increased urinary podocin level by 2.92-fold (p < 0.01). Thus, our study affirms that the efficacy of garlic oil blend was augmented upon nanoemulsification, which substantially ameliorated the renal abnormalities observed in the pre-diabetic condition than garlic oil blend or atorvastatin.

Qiliqiangxin Protects against Renal Injury in Rat with Cardiorenal Syndrome Type I through Regulating the Inflammatory and Oxidative Stress Signaling.

Cardiorenal syndrome (CRS) is a frequently encountered clinical condition when the dysfunction of either the heart or kidneys amplifies the failure progression of the other organ. CRS remains a major global health problem. Qiliqiangxin (QLQX) is a traditional Chinese herbs medication, which can improve cardiac function, urine volume, and subjective symptoms in patients with chronic heart failure. In the present study, we aim to investigate the role of QLQX in the treatment of CRS type I and the possible mechanism through establishment of a rat model of myocardial infarction. Rats in CRS-Q group were orally treated with QLQX daily for 2 weeks or 4 weeks, while in sham group and CRS-C group were treated with saline at the same time. Enzyme-linked immunosorbent assay (ELISA) analysis showed that QLQX significantly reduced the levels of angiotensin II (AngII), brain natriuretic peptides (BNP), creatinine (CRE), cystatin C (CysC), tumor necrosis factor (TNF)-α, interleukin (IL)-6, microalbuminuria (MAU), and neutrophil gelatinase-associated lipocalin (NGAL) in plasma induced by myocardial infarction. Western blot analysis showed that QLQX significantly reduced the expressions of AngII, non-phagocytic cell oxidase (NOX)2, and B-cell lymphoma (Bcl)2 associated X protein (Bax), and increased the expressions of Bcl2 and Angiotensin II Type 1 receptor (ATR) in the kidney as compared with the CRS-C group. Fluorescence microscopy showed that the content of reactive oxygen species (ROS) was significantly reduced in the kidney as compared with the CRS-C group. We also examined the apoptosis level in kidney by using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining, and the result showed that QLQX significantly reduced the apoptosis level in kidney induced by myocardial infarction. Taken together, we suggest that QLQX may be a potentially effective drug for the treatment of CRS by regulating inflammatory/oxidative stress signaling.

DHEA supplementation to dexamethasone-treated rabbits alleviates oxidative stress in kidney-cortex and attenuates albuminuria.

Our recent study has shown that dehydroepiandrosterone (DHEA) administered to rabbits partially ameliorated several dexamethasone (dexP) effects on hepatic and renal gluconeogenesis, insulin resistance and plasma lipid disorders. In the current investigation, we present the data on DHEA protective action against dexP-induced oxidative stress and albuminuria in rabbits. Four groups of adult male rabbits were used in the in vivo experiment: (1) control, (2) dexP-treated, (3) DHEA-treated and (4) both dexP- and DHEA-treated. Administration of dexP resulted in accelerated generation of renal hydroxyl free radicals (HFR) and malondialdehyde (MDA), accompanied by diminished superoxide dismutase (SOD) and catalase activities and a dramatic rise in urinary albumin/creatinine ratio. Treatment with DHEA markedly reduced dexP-induced oxidative stress in kidney-cortex due to a decline in NADPH oxidase activity and enhancement of catalase activity. Moreover, DHEA effectively attenuated dexP-evoked albuminuria. Surprisingly, dexP-treated rabbits exhibited elevation of GSH/GSSG ratio, accompanied by a decrease in glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities as well as an increase in glucose-6-phosphate dehydrogenase (G6PDH) activity. Treatment with DHEA resulted in a decline in GSH/GSSG ratio and glutathione reductase (GR) activity, accompanied by an elevation of GPx activity. Interestingly, rabbits treated with both dexP and DHEA remained the control values of GSH/GSSG ratio. As the co-administration of DHEA with dexP resulted in (i) reduction of oxidative stress in kidney-cortex, (ii) attenuation of albuminuria and (iii) normalization of glutathione redox state, DHEA might limit several undesirable renal side effects during chronic GC treatment of patients suffering from allergies, asthma, rheumatoid arthritis and lupus. Moreover, its supplementation might be particularly beneficial for the therapy of patients with glucocorticoid-induced diabetes.

Renoprotective Effect of the Shen-Yan-Fang-Shuai Formula by Inhibiting TNF-α/NF-κB Signaling Pathway in Diabetic Rats.

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease, and satisfactory therapeutic strategies have not yet been established. The Shen-Yan-Fang-Shuai Formula (SYFSF) is a traditional Chinese formula composed of Astragali radix, Radixangelicae sinensis, Rheum officinale Baill, and four other herbs. It has been widely used as an effective treatment for DKD patients in China. However, little is known about the molecular mechanisms underlying SYFSF's renoprotection. In this study, we compared the protective effect of SYFSF to irbesartan on the histology and renal cells in type 2 DKD rat model and high-glucose (HG) cultured mesangial cells, respectively. We found that SYFSF could significantly decrease urinary albumin, cholesterol, and triglyceride. And a decrease in serum creatinine was also found in SYFSF-treated group compared with irbesartan-treated rats. In addition, SYFSF inhibited the interstitial expansion and glomerulosclerosis in diabetic rats. Notably, SYFSF markedly downregulated the expression of MCP-1, TGF-ß1, collagen IV, and fibronectin in diabetic rat models and HG-induced mesangial cell models. The renoprotection was closely associated with a reduced expression of TNF-α and phosphorylated NF-κBp65. Our study suggests that SYFSF may ameliorate diabetic kidney injury. The observed renoprotection is probably attributable to an inhibition of inflammatory response and extracellular matrix (ECM) accumulation mediated by TNF-α/NF-κBp65 signaling pathway.

Restoration of Mimecan Expression by Grape Seed Procyanidin B2 Through Regulation of Nuclear Factor-kappaB in Mice With Diabetic Nephropathy.

Grape seed procyanidin B2 (GSPB2) exerts a variety of potent protective pharmacological effects on diabetic complications. The renal protective effects of GSPB2 and the target protein mimecan regulated by GSPB2, discovered in a previous quantitative proteomic analysis, were assessed in mice with diabetic nephropathy Twenty-four db/db mice were divided into 2 groups of the vehicle-treated and GSPB2-treated (30 mg/kg/d) diabetic groups. All animals were observed for 10 weeks. Treatment with GSPB2 resulted in an improvement in body weight increase and serum levels of triglyceride, total cholesterol, advanced glycation end products, and urinary albumin excretion in comparison with the vehicle-treated diabetic mice (P < .05), although these levels were still higher than those in the control group. Treatment with GSPB2 significantly reduced the extent of glomerular basement membranes thickening, mesangial expansion, and glomerular area as well. Mimecan protein expressions in diabetes mellitus were decreased approximately by 28% when compared with those in the control group (P < .05), and restored remarkably after GSPB2 treatment (P < .05). The expression of nuclear factor-κB (NF-κB) p65 in nuclear extracts, markedly higher in the diabetic mice than in the controls, was significantly suppressed by GSPB2. The findings of this study revealed that mimecan might become a new therapeutic target in the future and indicated that GSPB2 had beneficial effects not only on oxidative stress, but also on renal fibrosis, particularly in the diabetic kidney.

The use of green tea polyphenols for treating residual albuminuria in diabetic nephropathy: A double-blind randomised clinical trial.

Prior research has shown that in experimental diabetes mellitus, green tea reduces albuminuria by decreasing podocyte apoptosis through activation of the WNT pathway. We investigated the effect of green tea polyphenols (GTP) on residual albuminuria of diabetic subjects with nephropathy. We conducted a randomised, double-blind study in 42 diabetic subjects with a urinary albumin-creatinine ratio (UACR) >30 mg/g, despite administration of the maximum recommended dose of renin-angiotensin (RAS) inhibition. Patients were randomly assigned to two equal groups to receive either GTP (containing 800 mg of epigallocatechin gallate, 17 with type 2 diabetes and 4 with type 1 diabetes) or placebo (21 with type 2 diabetes) for 12 weeks. Treatment with GTP reduced UACR by 41%, while the placebo group saw a 2% increase in UACR (p = 0.019). Podocyte apoptosis (p = 0.001) and in vitro albumin permeability (p < 0.001) were higher in immortalized human podocytes exposed to plasma from diabetic subjects compared to podocytes treated with plasma from normal individuals. In conclusion, GTP administration reduces albuminuria in diabetic patients receiving the maximum recommended dose of RAS. Reduction in podocyte apoptosis by activation of the WNT pathway may have contributed to this effect.

Huangkui capsule, an extract from Abelmoschus manihot (L.) medic, improves diabetic nephropathy via activating peroxisome proliferator-activated receptor (PPAR)-α/γ and attenuating endoplasmic reticulum stress in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Abelmoschus manihot (L.) medic (AM) is a natural medicinal plant used for the treatment of chronic kidney disease (CKD) in China. Huangkui capsule (HKC), an extract from AM, has been proved clinically effective in improving renal inflammation and glomerular injury in CKD. However, the mechanisms of HKC are still not fully understood. AIM OF THE STUDY: Peroxisome proliferator-activated receptor (PPAR)-α/γ dual agonists have the potential to be used as therapeutic agents for the treatment of type 2 diabetes and diabetic nephropathy (DN). This study evaluated the function of Huangkui capsule (HKC), an extract from Abelmoschus manihot (L.) medic (AM), as a dual agonist for PPARα/γ and investigated its anti-DN effects in a DN rat model. MATERIALS AND METHODS: ChIP and reporter gene assays were performed and the expression of PPARα/γ target genes was monitored to examine the ability of HKC to activate PPARα/γ. DN was induced in male Sprague-Dawley rats via unilateral nephrectomy and intraperitoneal injection of streptozotocin. HKC was administered to the diabetic nephropathy rats at three different doses: high dose HKC (300mg/kg/d); middle dose HKC (175mg/kg/d); and low dose HKC (75mg/kg/d). Irbesartan (4mg/kg/d body weight) was used as a positive control. Following 12 weeks' treatment, we measured general status, renal morphological appearance, proteinuria, blood biochemical parameters, and glomerular morphological changes. The expression of collagen IV, TGFß, TNFα and IL-6 in renal tissue was evaluated. Endoplasmic reticulum (ER) stress in renal tissue was also analyzed. RESULTS: HKC enhanced the transcriptional activity of PPARα and PPARγ in cultured cells, livers and kidneys of DN rats, and it reduced serum triglyceride and cholesterol levels and fat in livers of DN rats. Furthermore, HKC reduced the expressions of inflammatory genes in kidneys of DN rats. Strikingly, HKC reduced ER stress and c-Jun NH2-terminal kinase activation in the liver and kidney of DN rats and subsequently improved renal injury. CONCLUSIONS: Our results show that HKC improved lipid metabolic disorders by activating PPARα/γ and attenuating ER stress. HKC could dose-dependently ameliorate renal inflammation and glomerular injury in DN rats. These results suggest that HKC has potential as an anti-DN agent for the treatment of DN in humans.

1,25-Vitamin D3 Deficiency Induces Albuminuria.

Vitamin D plays an important role in renal (patho)physiology. Patients with glomerular diseases have an injured renal filtration barrier, leading to proteinuria and reduced renal function. An impaired renal function also leads to 1,25-vitamin D3 deficiency as a result of reduced renal 1α-hydroxylase activity. Vitamin D treatment to reduce proteinuria remains controversial, although there is an inverse correlation between vitamin D levels and proteinuria. Herein, we showed that 1,25-vitamin D3-deficient 25-hydroxy-vitamin-D3-1α-hydroxylase knockout mice and 1,25-vitamin D3-deficient rats develop podocyte injury and renal dysfunction. Glomerular injury was characterized by proteinuria and partial podocyte foot process effacement. Expression of nephrin, podocin, desmin, and transient receptor potential channel C6 in the podocyte was significantly altered in 1,25-vitamin D3-deficient animals. Supplementation with 1,25-vitamin D3 or 1,25-vitamin D2 prevented podocyte effacement or reversed glomerular and tubulointerstitial damage in 1,25-vitamin D3-deficient animals, thereby preserving and restoring renal function, respectively. The effect of 1,25-vitamin D3 deficiency and 1,25-vitamin D3 and 1,25-vitamin D2 repletion on proteinuria could not be explained by hypocalcemia, changes in parathyroid hormone, or fibroblast growth factor 23. This study demonstrates that 1,25-vitamin D3 deficiency directly leads to renal injury in rodents. Translated to human subjects, this would underline the need for early vitamin D supplementation in patients with glomerular disease and chronic renal insufficiency, which might inhibit or potentially reverse renal injury.

A novel mechanism of action for salidroside to alleviate diabetic albuminuria: effects on albumin transcytosis across glomerular endothelial cells.

Salidroside (SAL) is a phenylethanoid glycoside isolated from the medicinal plant Rhodiola rosea. R. rosea has been reported to have beneficial effects on diabetic nephropathy (DN) and high-glucose (HG)-induced mesangial cell proliferation. Given the importance of caveolin-1 (Cav-1) in transcytosis of albumin across the endothelial barrier, the present study was designed to elucidate whether SAL could inhibit Cav-1 phosphorylation and reduce the albumin transcytosis across glomerular endothelial cells (GECs) to alleviate diabetic albuminuria as well as to explore its upstream signaling pathway. To assess the therapeutic potential of SAL and the mechanisms involved in DN albuminuria, we orally administered SAL to db/db mice, and the effect of SAL on the albuminuria was measured. The albumin transcytosis across GECs was explored in a newly established in vitro cellular model. The ratio of albumin to creatinine was significantly reduced upon SAL treatment in db/db mice. SAL decreased the albumin transcytosis across GECs in both normoglycemic and hyperglycemic conditions. SAL reversed the HG-induced downregulation of AMP-activated protein kinase and upregulation of Src kinase and blocked the upregulation Cav-1 phosphorylation. Meanwhile, SAL decreased mitochondrial superoxide anion production and moderately depolarized mitochondrial membrane potential. We conclude that SAL exerts its proteinuria-alleviating effects by downregulation of Cav-1 phosphorylation and inhibition of albumin transcytosis across GECs. These studies provide the first evidence of interference with albumin transcytosis across GECs as a novel approach to the treatment of diabetic albuminuria.

Novel Stratification of Mortality Risk by Kidney Disease Stage.

BACKGROUND: Chronic kidney disease (CKD) is a common disorder with a variable clinical course and it is associated with increased mortality. The Intermountain Risk Score (IMRS) is an electronic risk calculator that utilizes complete blood count (CBC) and basic metabolic panel (BMP) values to predict mortality in various healthcare populations. We hypothesized that IMRS would predict mortality in patients with CKD even with adjustment for serum phosphate and urinary albumin. METHODS: Three thousand eight hundred seventy-two patients with CKD classes IIIA-V had IMRS calculated retrospectively and survival analysis was performed investigating 1- and 5-year mortality. Kaplan-Meier survival curves were generated for predefined IMRS groups of low, medium and high risk for CKD patients overall and by sex and CKD stage. Serum phosphate and urinary albumin/creatinine ratios were modeled in multivariate Cox-proportional hazard models. Receiver operator characteristic curves were used to determine c-statistics for mortality. RESULTS: For all patients with CKD, mortality was significantly greater for those with medium- or high-risk compared to low-risk IMRS categories, among each CKD stage. Overall, IMRS was predictive of mortality at both 1 and 5 years, even when adjusted for CKD stage and predicted mortality more accurately than CKD stage alone. Albuminuria was not independently associated with mortality and serum phosphate weakly predicted mortality. CONCLUSION: IMRS is a strong predictor of mortality in patients with CKD and is robustly complementary to CKD stage in refining risk prediction. Given the universal availability and low cost of the CBC and BMP, IMRS may be of a substantial value in CKD risk assessment and management.

Effects of physical training and potassium supplementation on blood pressure, glucose metabolism and albuminuria of spontaneously hypertensive rats.

INTRODUCTION: It is still controversial whether there are synergistic effects among different non-pharmacological interventions used in the treatment of hypertension. OBJECTIVES: To evaluate the effect of aerobic exercise, oral supplementation of potassium and their combination on blood pressure, glucose metabolism, urinary albumin excretion and glomerular morphology in spontaneously hypertensive rats (SHR). METHODS: SHR were divided into groups: Control Group (SHR; standard diet and sedentary, n = 10), Exercise Group (SHR + E; trained on a treadmill, standard diet, n = 10), Potassium Group (SHR + K; sedentary, potassium supplementation, n = 10) and Group Exercise + Potassium (SHR + E + K, exercise, potassium supplementation n = 10). Weekly, body weight (BW) and tail blood pressure (TAP) were measured. At the end of 16 weeks, a Oral Glucose Tolerance Test was performed. Albuminuria was determined in the baseline period, at 8th and at 16th week. After sacrifice, the analysis of glomerular sclerosis index and visceral fat weight was performed. RESULTS: The TAP and BW did not change significantly. There was improvement in insulin sensitivity in SHR + E and SHR + K, but not in SHR + E + K. At week 16, albuminuria in all groups was significantly lower than the SHR control. The glomerular sclerosis index and visceral fat content were also significantly lower in all groups compared to control. CONCLUSION: An oral supplementation of potassium and exercise led to an improvement in glucose metabolism, in albuminuria and glomerular morphology, however, the overlap of the treatments did not show synergism.

Efeito do exercício físico e suplementação de potássio sobre a pressão arterial, metabolismo glicídico e albuminúria de ratos hipertensos / Effects of physical training and potassium supplementation on blood pressure, glucose metabolism and albuminuria of spontaneously hypertensive rats

Introdução: Ainda é controverso se ocorre sinergismo entre as diferentes medidas não farmacológicas utilizadas no tratamento da hipertensão arterial. Objetivo: Avaliar o efeito do exercício físico aeróbico, da sobrecarga oral de potássio e da sua associação sobre a pressão arterial, metabolismo glicídico, excreção urinária de albumina e morfologia glomerular de ratos espontaneamente hipertensos (SHR). Métodos: SHRs foram divididos em: Grupo Controle (SHR; dieta padrão e sedentário, n = 10); Grupo Exercício (SHR + E; treinado em esteira rolante, dieta padrão, n = 10), Grupo Potássio (SHR + K; sedentário, dieta rica em potássio, n = 10) e Grupo Exercício + Potássio (SHR + E + K; exercitado, dieta rica em potássio, n = 10). Semanalmente, foi aferido o peso corporal (PC) e a pressão arterial de cauda (PAC). Ao final de 16 semanas, foi realizado o Teste de Tolerância oral a Glicose. A albuminúria foi determinada nos períodos basal, na 8ª e 16ª semana. Após o sacrifício, foi realizada a análise do índice de esclerose glomerular e a pesagem da gordura visceral. Resultados: A PAC e o PC não variaram significativamente. Houve melhora da sensibilidade à insulina no Grupo Exercício e Grupo Potássio, mas não no Grupo Exercício + Potássio. Na 16ª semana, a albuminúria de todos os grupos foi significativamente menor que o grupo SHR Controle. O índice de esclerose glomerular e o peso da gordura visceral também foram significativamente menores em todos os grupos tratados quando comparados ao controle. Conclusão: A dieta rica em potássio e o exercício físico determinaram melhora no metabolismo glicídico, na albuminúria e na morfologia glomerular, porém, a sobreposição ...

Introduction: It is still controversial whether there are synergistic effects among different non-pharmacological interventions used in the treatment of hypertension. Objetives: To evaluate the effect of aerobic exercise, oral supplementation of potassium and their combination on blood pressure, glucose metabolism, urinary albumin excretion and glomerular morphology in spontaneously hypertensive rats (SHR). Methods: SHR were divided into groups: Control Group (SHR; standard diet and sedentary, n = 10), Exercise Group (SHR + E; trained on a treadmill, standard diet, n = 10), Potassium Group (SHR + K; sedentary, potassium supplementation, n = 10) and Group Exercise + Potassium (SHR + E + K, exercise, potassium supplementation n = 10). Weekly, body weight (BW) and tail blood pressure (TAP) were measured. At the end of 16 weeks, a Oral Glucose Tolerance Test was performed. Albuminuria was determined in the baseline period, at 8th and at 16th week. After sacrifice, the analysis of glomerular sclerosis index and visceral fat weight was performed. Results: The TAP and BW did not change significantly. There was improvement in insulin sensitivity in SHR + E and SHR + K, but not in SHR + E + K. At week 16, albuminuria in all groups was significantly lower than the SHR control. The glomerular sclerosis index and visceral fat content were also significantly lower in all groups compared to control. Conclusion: An oral supplementation of potassium and exercise led to an improvement in glucose metabolism, in albuminuria and glomerular morphology, however, the overlap of the treatments did not show synergism. .

P2X(7) receptor in the kidneys of diabetic rats submitted to aerobic training or to N-acetylcysteine supplementation [corrected].

Previous studies in our laboratory showed that N-acetylcysteine supplementation or aerobic training reduced oxidative stress and the progression of diabetic nephropathy in rats. The P2X(7 receptor is up-regulated in pathological conditions, such as diabetes mellitus. This up-regulation is related to oxidative stress and induces tissue apoptosis or necrosis. The aim of the present study is to assess the role of P2X(7) receptor in the kidneys of diabetic rats submitted to aerobic training or N-acetylcysteine supplementation. Diabetes was induced in male Wistar rats by streptozotocin (60 mg/kg, i.v.) and the training was done on a treadmill; N-acetylcysteine was given in the drinking water (600 mg/L). By confocal microscopy, as compared to control, the kidneys of diabetic rats showed increased P2 × 7 receptor expression and a higher activation in response to 2'(3')-O-(4-benzoylbenzoyl) adenosine5'-triphosphate (specific agonist) and adenosine triphosphate (nonspecific agonist) (all p<0.05). All these alterations were reduced in diabetic rats treated with N-acetylcysteine, exercise or both. We also observed measured proteinuria and albuminuria (early marker of diabetic nephropathy) in DM groups. Lipoperoxidation was strongly correlated with P2X(7) receptor expression, which was also correlated to NO•, thus associating this receptor to oxidative stress and kidney lesion. We suggest that P2X(7) receptor inhibition associated with the maintenance of redox homeostasis could be useful as coadjuvant treatment to delay the progression of diabetic nephropathy.

Alkaloids of Nitraria sibirica Pall. decrease hypertension and albuminuria in angiotensin II-salt hypertension.

In traditional Chinese medicine, Nitraria sibirica Pall. (Nitrariaceae) is used to treat hypertension. This study determined the effects of the total alkaloids of the leaves of Nitraria sibirica (NSTA) on blood pressure and albuminuria in mice treated with angiotensin II and a high-salt diet (ANG/HS). Adult mice were divided into three groups: control; infused with angiotensin II and fed a diet containing 4% NaCl (ANG/HS; and ANG/HS plus injection of NSTA (1 mg·kg(-1)·d(-1), i.p.). After treatment of these regimens, daily water and food intake, kidney weight, blood pressure, urinary albumin excretion, renal concentrations of inflammatory markers, including soluble intercellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1), and the expression of renal fibrosis markers were determined. Compared to the control group, the ANG/HS group had higher blood pressure and urinary albumin excretion. Treatment with NSTA in ANG/HS mice for three weeks significantly reduced blood pressure and urinary albumin excretion. ANG/HS treatment caused elevated levels of sICAM-1 and MCP-1, as well as increased fibrosis markers. Concurrent treatment with ANG/HS and NSTA attenuated the levels and expression of renal inflammatory and fibrosis markers. Treatment with NSTA effectively reduces hypertension-induced albuminuria through the reduction of renal inflammatory and fibrosis markers.