Melanocyte colonization and pigmentation of breast carcinoma: A case report.

Pigmented mammary Paget disease is a rare variant of mammary Paget disease that is often clinically misdiagnosed as a melanocytic lesion of the skin or nipple-areolar complex. Careful morphological assessment, along with the performance of adequate immunohistochemical stains, will help in achieving the right diagnosis and avoiding misdiagnosis of the entity as malignant melanoma. We report a rare case of pigmented mammary Paget disease with concomitant colonization of the underlying invasive ductal carcinoma by melanocytes mimicking melanoma.

Rubella virus-associated necrotizing neutrophilic granuloma in a patient with common variable immunodeficiency.

Patients with inborn errors of immunity (IEI) may develop granulomas in multiple organ systems including the skin. Vaccine strain rubella virus (RuV), part of the live attenuated measles, mumps, and rubella (MMR) vaccine, has been identified within these granulomas. RuV is typically found in macrophages; however, recently neutrophils have been identified as a novel cell type infected. Here, we present a case of RuV-associated cutaneous granuloma with RuV localized to neutrophils. A 46-year-old female with common variable immunodeficiency presented with verrucous papules and crusted plaques from the right knee to the distal shin of 20 years duration, associated with prior physical trauma. Biopsy specimen showed palisaded granulomas surrounding central necrosis with scattered aggregates of neutrophils. Vaccine-derived RuV was detected by molecular sequencing in lesional skin. Fluorescent immunohistochemistry with CD206, myeloperoxidase (MPO), and RV capsid (RVC) antibodies demonstrated that RuV localized to neutrophils but not macrophages. The clinical presentation, cutaneous findings, and likely presence of RVC-positive granulocytes in bone marrow provide potential support to the evolving hypothesis of persistent RuV within neutrophils contributing to chronic granulomatous inflammation in a milieu of immune dysregulation.

Galectin-3 Is Associated with Cardiac Fibrosis and an Increased Risk of Sudden Death.

BACKGROUND: Myocardial fibrosis is a common postmortem finding among individuals with Sudden Cardiac Death (SCD). Numerous in vivo and in vitro studies have shown that increased galectin-3 (gal3) expression into the myocardium is associated with higher incidence of fibrosis. Although elevated gal3 expression is linked with myocardial fibrosis, its role in predicting the risk of SCD is unknown. METHODS: We reviewed the clinical datasets and post-mortem examination of 221 subjects who had died suddenly. We examined myocardial pathology including the extent of cardiac hypertrophy, fibrosis, and the degree of coronary atherosclerosis in these subjects. In a select group of SCD subjects, we studied myocardial gal3 and periostin expression using immunohistochemistry. To further examine if a higher level of circulating gal3 can be detected preceding sudden death, we measured serum gal3 in a porcine model of subtotal coronary artery ligation which shows an increased tendency to develop lethal cardiac arrhythmias, including ventricular tachycardia or fibrillation. RESULTS: Of the total 1314 human subjects screened, 12.7% had SCD. Comparison of age-matched SCD with non-SCD subjects showed that SCD groups had excessive myocardial fibrosis involving both the left ventricular free wall and interventricular septum. In pigs with subtotal coronary artery ligation and SCD, we detected significantly elevated circulating gal3 levels approximately 10 days preceding the SCD event. Immunohistochemistry showed increased myocardial gal3 and periostin expression in pigs that died suddenly, compared to the controls. CONCLUSION: Our study shows that increased gal3 is associated with a higher risk of myocardial fibrosis and the risk of SCD. This supports the importance of larger translational studies to target gal3 to prevent cardiac fibrosis and attenuate the risk of SCD.

Tetrahydrocurcumin Add-On therapy to losartan in a rat model of diabetic nephropathy decreases blood pressure and markers of kidney injury.

Tetrahydrocurcumin (THC), a principal metabolite of curcumin, was tested in a rat model of type 2 diabetes mellitus. THC was administered via daily oral gavage with the lipid carrier polyenylphosphatidylcholine (PPC) as add-on therapy to losartan (angiotensin receptor blocker) to examine effects on kidney oxidative stress and fibrosis. A combination of unilateral nephrectomy, high-fat diet and low-dose streptozotocin was used to induce diabetic nephropathy in male Sprague-Dawley rats. Animals with fasting blood glucose >200 mg/dL were randomized to PPC, losartan, THC + PPC or THC + PPC + losartan. Untreated chronic kidney disease (CKD) animals had proteinuria, decreased creatinine clearance, and evidence of kidney fibrosis on histology. THC + PPC + losartan treatment significantly lowered blood pressure concurrent with increased messenger RNA levels of antioxidant copper-zinc-superoxide dismutase and decreased protein kinase C-α, kidney injury molecule-1 and type I collagen in the kidneys; there was decreased albuminuria and a trend for increased creatinine clearance compared to untreated CKD rats. There was decreased fibrosis on kidney histology in PPC-only and THC-treated CKD rats. Plasma levels of kidney injury molecule-1 were decreased in THC + PPC + losartan animals. In summary, add-on THC to losartan therapy improved antioxidant levels and decreased fibrosis in the kidneys, and lowered blood pressure in diabetic CKD rats.

Concomitant nivolumab-associated Grover disease and bullous pemphigoid in a patient with metastatic renal cell carcinoma.

Immune checkpoint inhibitor (ICI)-induced bullous pemphigoid (BP) and Grover disease (GD) are uncommon, and concomitant GD and BP is rarer still. We report a third case of concomitant BP and GD associated with nivolumab with emphasis on the clinical, histopathologic and immunofluorescence findings as well as differential diagnoses. A 73-year-old male with metastatic renal cell carcinoma on nivolumab developed erythematous scaly papules on the trunk with biopsy showing suprabasal acantholysis with dyskeratosis, consistent with GD. Subsequently, he developed widespread lesions on arms, legs, trunk, and scrotum with new vesiculobullae and urticarial lesions. Biopsy of a vesicle showed subepidermal blister with numerous eosinophils and neutrophils, and immunofluorescence and serological studies were supportive of BP. He continued to have clinically apparent GD that was confirmed on repeat biopsy. The patient was diagnosed with concomitant GD and BP induced by nivolumab and successfully treated with dupilumab. The relationship between ICI-induced GD and BP is not well understood; it has been suggested that T-cell activation against the BP180 antigen expressed on surface of tumor cells may predispose susceptible individuals to BP. Subsequent ICI-induced GD may create keratinocyte injury needed to expose additional proteins to reactivated and autoreactive T-cells, leading to autoimmunity. An important differential diagnosis is bullous GD, which can be distinguished by negative immunofluorescence and serological studies.

The Clinical Utility and Impact of Next Generation Sequencing in Gynecologic Cancers.

Next generation sequencing (NGS) has facilitated the identification of molecularly targeted therapies. However, clinical utility is an emerging challenge. Our objective was to identify the clinical utility of NGS testing in gynecologic cancers. A retrospective review of clinico-pathologic data was performed on 299 gynecological cancers where NGS testing had been performed to identify (1) recognition of actionable targets for therapy, (2) whether the therapy changed based on the findings, and (3) the impact on survival. High grade serous carcinoma was the most common tumor (52.5%). The number of genetic alterations ranged from 0 to 25 with a mean of 2.8/case. The most altered genes were TP53, PIK3CA, BRCA1 and BRCA2. Among 299 patients, 100 had actionable alterations (79 received a targeted treatment (Group1), 29 did not receive treatment (Group 2), and there were no actionable alterations in 199 (Group3). The death rate in groups 1, 2 and 3 was 54.4%, 42.8% and 50.2%, with an average survival of 18.6, 6.6 and 10.8 months, respectively (p = 0.002). In summary, NGS testing for gynecologic cancers detected 33.4% of actionable alterations with a high clinical action rate. Along with the high clinical utility of NGS, testing also seemed to improve survival for patients who received targeted treatment.

RNA Interference Targeting Liver Angiopoietin-Like Protein 3 Protects from Nephrotic Syndrome in a Rat Model Via Amelioration of Pathologic Hypertriglyceridemia.

Nephrotic syndrome (NS) is associated with metabolic perturbances including profound dyslipidemia characterized by hypercholesterolemia and hypertriglyceridemia. A major underlying mechanism of hypertriglyceridemia in NS is lipoprotein lipase (LPL) deficiency and dysfunction. There is emerging evidence that elevated angiopoietin-like protein 3 (ANGPTL3), an LPL inhibitor that is primarily expressed and secreted by hepatocytes, may be in part responsible for these findings. Furthermore, there is evidence pointing to the contribution of ANGPTL3 to the pathogenesis of proteinuria in NS. Therefore, we hypothesized that inhibition of hepatic ANGPTL3 by RNA interference will ameliorate dyslipidemia and other symptoms of NS and pave the way for a new therapeutic strategy. To this end, we used a subcutaneously delivered, GalNAc (N-Acetylgalactosamine)-conjugated small interfering RNA (siRNA) to selectively target and suppress liver Angptl3 in rats with puromycin-induced NS, which exhibits clinical features of NS including proteinuria, hypoalbuminemia, hyperlipidemia, and renal histologic abnormalities. The study demonstrated that siRNA-mediated knockdown of the liver Angptl3 relieved its inhibitory effect on LPL and significantly reduced hypertriglyceridemia in nephrotic rats. This was accompanied by diminished proteinuria and hypoalbuminemia, which are the hallmarks of NS, and significant attenuation of renal tissue inflammation and oxidative stress. Taken together, this study confirmed the hypothesis that suppression of Angptl3 is protective in NS and points to the possibility that the use of RNA interference to suppress hepatic Angptl3 can serve as a novel therapeutic strategy for NS. SIGNIFICANCE STATEMENT: The current standard of care for mitigating nephrotic dyslipidemia in nephrotic syndrome is statins therapy. However, the efficacy of statins and its safety in the context of impaired kidney function is not well established. Here, we present an alternate therapeutic approach by using siRNA targeting Angptl3 expressed in hepatocytes. As the liver is the major source of circulating Angptl3, siRNA treatment reduced the profound hypertriglyceridemia in a rat model of nephrotic syndrome and was also effective in improving kidney and cardiac function.

Route of intestinal absorption and tissue distribution of iron contained in the novel phosphate binder ferric citrate.

BACKGROUND: Anemia of chronic kidney disease (CKD) is, in part, caused by hepcidin-mediated impaired iron absorption. However, phosphate binder, ferric citrate (FC) overcomes the CKD-induced impairment of iron absorption and increases serum iron, transferrin saturation, and iron stores and reduces erythropoietin requirements in CKD/ESRD patients. The mechanism and sites of intestinal absorption of iron contained in FC were explored here. METHODS: Eight-week old rats were randomized to sham-operated or 5/6 nephrectomized (CKD) groups and fed either regular rat chow or rat chow containing 4% FC for 6 weeks. They were then euthanized, and tissues were processed for histological and biochemical analysis using Prussian blue staining, Western blot analysis to quantify intestinal epithelial tight junction proteins and real-time PCR to measure Fatty Acid receptors 2 (FFA2) and 3 (FFA3) expressions. RESULTS: CKD rats exhibited hypertension, anemia, azotemia, and hyperphosphatemia. FC-treated CKD rats showed significant reductions in blood pressure, serum urea, phosphate and creatinine levels and higher serum iron and blood hemoglobin levels. This was associated with marked increase in iron content of the epithelial and subepithelial wall of the descending colon and modest iron deposits in the proximal tubular epithelial cells of their remnant kidneys. No significant difference was found in hepatic tissue iron content between untreated and FC-treated CKD or control groups. Distal colon's epithelial tight Junction proteins, Occludin, JAM-1 and ZO-1 were markedly reduced in the CKD groups. The FFA2 expression in the jejunum and FFA3 expression in the distal colon were significantly reduced in the CKD rats and markedly increased with FC administration. CONCLUSION: Iron contained in the phosphate binder, FC, is absorbed by the distal colon of the CKD animals via disrupted colonic epithelial barrier and upregulation of short chain fatty acid transporters.

Ferric Citrate Attenuates Cardiac Hypertrophy and Fibrosis in a Rat Model of Chronic Kidney Disease.

INTRODUCTION: Chronic kidney disease (CKD) promotes hypertrophy and fibrosis in heart, and increases the risk of cardiovascular mortality. Ferric citrate is a dietary phosphate binder used to control hyperphosphatemia in CKD patients. It has been shown to raise iron stores, improve anemia and secondary hyperparathyroidism, and decrease vascular calcification in CKD patients. The present study was done to explore the effects and mechanism of actions of ferric citrate on cardiac hypertrophy and fibrosis. MATERIALS AND METHODS: Male SD rats were randomized to CKD (5/6 nephrectomized) and sham-operated control groups. CKD rats were fed regular diet or a diet containing 4% ferric citrate. After 8 weeks, hemoglobin, renal function and cardiovascular endpoints including blood pressure, heart/body weight ratio, serum N-terminal prohormone of brain natriuretic peptide (NT-proBNP), cardiac histology and markers of hypertrophy, fibrosis and inflammation were assessed. RESULTS: Compared to the controls, untreated CKD group exhibited hypertension, elevated serum urea, creatinine, phosphate, and NT-proBNP concentrations, anemia, cardiomegaly ,cardiac hypertrophy and fibrosis. Treatment with ferric citrate significantly increased hemoglobin and serum iron concentrations, reduced serum phosphate and NT-proBNP levels and ameliorated hypertension, heart/body weight ratio, cardiac hypertrophy, fibrosis and inflammation. In addition, ferric citrate administration reduced the size of cardiomyocytes and expressions of myocardin, transforming growth factor-ß, interleukin-6 and monocyte chemotactic protein 1. CONCLUSIONS: Treatment with ferric citrate attenuated renal failure and cardiovascular abnormalities including myocardial hypertrophy and fibrosis in CKD rats.

The Phosphate Binder Ferric Citrate Alters the Gut Microbiome in Rats with Chronic Kidney Disease.

In chronic kidney disease (CKD), the gut microbiome is altered and bacterial-derived uremic toxins promote systemic inflammation and cardiovascular disease. Ferric citrate complex is a dietary phosphate binder prescribed for patients with end-stage kidney disease to treat hyperphosphatemia and secondary hyperparathyroidism. Iron is an essential nutrient in both microbes and mammals. This study was undertaken to test the hypothesis that the large iron load administered with ferric citrate in CKD may significantly change the gut microbiome. Male Sprague-Dawley rats underwent 5/6 nephrectomy to induce CKD. Normal control and CKD rats were randomized to regular chow or a 4% ferric citrate diet for 6 weeks. Fecal and cecal microbial DNA was analyzed via 16S ribosomal RNA gene sequencing on the Illumina MiSeq system. CKD rats had lower abundances of Firmicutes and Lactobacillus compared with normal rats and had lower overall gut microbial diversity. CKD rats treated with ferric citrate had improved hemoglobin and creatinine clearance and amelioration of hyperphosphatemia and hypertension. Ferric citrate treatment increased bacterial diversity in CKD rats almost to levels observed in control rats. The tryptophanase-possessing families Verrucomicrobia, Clostridiaceae, and Enterobacteriaceae were increased by ferric citrate treatment. The uremic toxins indoxyl sulfate and p-cresyl sulfate were not increased with ferric citrate treatment. Verrucomicrobia was largely represented by Akkermansia muciniphila, which has important roles in mucin degradation and gut barrier integrity. In summary, ferric citrate therapy in CKD rats was associated with significant changes in the gut microbiome and beneficial kidney and blood pressure parameters.

Phosphate Binder, Ferric Citrate, Attenuates Anemia, Renal Dysfunction, Oxidative Stress, Inflammation, and Fibrosis in 5/6 Nephrectomized CKD Rats.

Chronic kidney disease (CKD) causes anemia and impairs intestinal iron absorption. However, use of the phosphate binder ferric citrate (FC) increases body iron stores and hemoglobin levels in CKD patients. By intensifying oxidative stress and inflammation iron overload resulting from excessive use of intravenous iron can accelerate CKD progression. The present study explored the route of absorption and tissue distribution of iron with FC administration and its effect on renal function, histology, and inflammatory, oxidative, and fibrosis pathways in CKD rats. Male Sprague Dawley rats were randomized to sham-operated control (CTL) group and 5/6 nephrectomized (CKD) groups fed either regular or 4% FC-supplemented diets for 6 weeks. Animals were then sacrificed, and blood and target tissues were harvested and processed. The untreated CKD rats exhibited anemia, hypertension, upregulation of renal tissue inflammatory, oxidative, and fibrotic pathways, impaired nuclear translocation, and downregulation of Nrf2's target gene products and depletion of colonic epithelial tight junction proteins. FC administration raised serum iron, improved anemia, attenuated hyperphosphatemia, partially improved renal function, reduced oxidative stress, inflammation, and fibrosis, and restored colonic epithelial zonula occludens-1 protein abundance. Tissue iron staining detected presence of iron in epithelial cells and subepithelium of colon and in renal proximal tubules. In conclusion ferric citrate administration resulted in modest amelioration of renal function and histology and partial improvements of fibrosis, inflammation, and oxidative stress in the kidney tissues of CKD rats.

Dietary tetrahydrocurcumin reduces renal fibrosis and cardiac hypertrophy in 5/6 nephrectomized rats.

Tetrahydrocurcumin (THC) is the principal metabolite of curcumin and has antioxidant properties. In the present investigation, the effect of THC on renal and cardiovascular outcomes was studied in rats with chronic kidney disease (CKD). CKD rats were randomized following 5/6 nephrectomy to a special diet for 9 weeks which contained 1% THC (CKD+THC group). Low-dose polyenylphosphatidylcholine was used as a lipid carrier to increase bioavailability. Endpoints included tail blood pressure, normalized heart weight, plasma and urine biochemical data, and kidney tissue analyses. CKD animals demonstrated increased proteinuria, decreased creatinine clearance, hypertension, and cardiac hypertrophy. The antioxidant proteins CuZn SOD and glutathione peroxidase were decreased in the remnant kidney, while apoptosis (caspase-3) and fibrosis (alpha-SM actin) were increased. Renal fibrosis was confirmed histologically on trichrome staining. These pathologic changes were ameliorated in the CKD+THC group with significant decrease in proteinuria, hypertension, and kidney fibrosis. THC therapy restored levels of CuZn SOD and glutathione peroxidase. Consistent with prior reports, dietary THC did not improve nuclear Nrf2 levels. In summary, dietary THC therapy improved expression of antioxidant proteins in the remnant kidney, decreased renal fibrosis and proteinuria, and ameliorated hypertension in 5/6 nephrectomized rats.

LCZ696 (Sacubitril/Valsartan), an Angiotensin-Receptor Neprilysin Inhibitor, Attenuates Cardiac Hypertrophy, Fibrosis, and Vasculopathy in a Rat Model of Chronic Kidney Disease.

BACKGROUND: Chronic kidney disease (CKD) is associated with cardiac hypertrophy, fibrosis, and increased risk of cardiovascular mortality. LCZ696 (sacubitril/valsartan) is a promising agent that has shown significant potential in treatment of heart failure. We hypothesized that LCZ696 is more effective than valsartan alone in the treatment of cardiovascular abnormalities associated with experimental CKD. METHODS AND RESULTS: Male Sprague-Dawley rats underwent 5/6 nephrectomy and were subsequently randomized to no treatment (CKD), 30 mg/kg valsartan (VAL), or 60 mg/kg LCZ696 (LCZ). After 8 weeks, cardiovascular parameters, including markers of inflammation, oxidative stress, mitochondrial abundance/function, hypertrophy, and fibrosis, were measured. Treatment with LCZ resulted in significant improvements in the heart-body weight ratio and serum concentrations of N-terminal pro-B-type natriuretic peptide and fibroblast growth factor 23 along with improvement of kidney function. In addition, LCZ ameliorated aortic fibrosis and cardiac hypertrophy and fibrosis, reduced markers of cardiac oxidative stress and inflammation, and improved indicators of mitochondrial mass/function. Although VAL also improved some of these indices, treatment with LCZ was more effective than VAL alone. CONCLUSIONS: CKD-associated cardiovascular abnormalities, including myocardial hypertrophy, fibrosis, inflammation, oxidative stress, and mitochondrial depletion/dysfunction, were more effectively attenuated by LCZ treatment than by VAL alone.

LCZ696 (Sacubitril/valsartan) ameliorates oxidative stress, inflammation, fibrosis and improves renal function beyond angiotensin receptor blockade in CKD.

Progressive deterioration of kidney function in chronic kidney disease (CKD) is mediated by hypertension, oxidative stress, inflammation, and fibrosis. Renin-angiotensin blockade is commonly used to retard CKD progression. In addition, vasoactive peptides have been shown to reduce blood pressure and exert antioxidant, anti-inflammatory and anti-fibrotic effects. We hypothesized that administration of LCZ696 (sacubitril/valsartan) is more effective than valsartan alone in slowing progression of CKD. Male Sprague Dawley rats underwent sham surgery or 5/6 nephrectomy and after two weeks the CKD animals were randomized to no treatment, valsartan (30 mg/kg), or LCZ696 (60 mg/kg) daily by gavage. Serum, urine and kidney tissue analyses were performed after 8 weeks. The untreated CKD rats exhibited hypertension, proteinuria, tubular and glomerular damage, upregulation of pro-inflammatory, pro-oxidant and pro-fibrotic pathways; reduction in nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its key target products. LCZ696 administration improved renal function and histology and attenuated most of the molecular markers of oxidative stress, inflammation and fibrosis. Furthermore, LCZ696 was more effective than valsartan therapy alone in delaying the progression of kidney disease. Future clinical trials are needed to determine the safety and efficacy of this agent in treatment of patients with CKD.

Effects of end-stage renal disease and dialysis modalities on blood ammonia level.

INTRODUCTION: Uremia results in a characteristic breath odor (uremic fetor) which is largely due to its high ammonia content. Earlier studies have shown a strong correlation between breath ammonia and blood urea levels and a 10-fold reduction in breath ammonia after hemodialysis in patients with chronic kidney disease. Potential sources of breath ammonia include: (i) local ammonia production from hydrolysis of urea in the oropharyngeal and respiratory tracts by bacterial flora, and (ii) release of circulating blood ammonia by the lungs. While the effects of uremia and hemodialysis on breath ammonia are well known their effects on blood ammonia are unknown and were explored here. METHODS: Blood samples were obtained from 23 hemodialysis patients (immediately before and after dialysis), 14 peritoneal dialysis patients, and 10 healthy controls. Blood levels of ammonia, creatinine, urea, and electrolytes were measured. FINDINGS: No significant difference was found in baseline blood ammonia between hemodialysis, peritoneal dialysis and control groups. Hemodialysis procedure led to a significant reduction in urea concentration (P < 0.001) which was paradoxically accompanied by a modest but significant (P < 0.05) rise in blood ammonia level in 10 of the 23 patients studied. Change in blood ammonia pre- and post-hemodialysis correlated with change in serum bicarbonate levels (r = 0.61, P < 0.01). On subgroup analysis of patients who had a rise in blood ammonia levels after dialysis, there was a strong correlation with drop in mean arterial pressure (r = 0.88, P < 0.01). The nadir intradialytic systolic blood pressure trended lower in the hemodialysis patients who had a rise in blood ammonia compared to the patients who manifested a fall in blood ammonia (124 ± 8 vs. 136 ± 6 mmHg respectively, P = 0.27). DISCUSSION: Fall in blood urea following hemodialysis in ESRD patients was paradoxically accompanied by a modest rise in blood ammonia levels in 43% of the patients studied, contrasting prior reported effects of hemodialysis on breath ammonia. In this subgroup of patients, changes in blood ammonia during hemodialysis correlated with rise in blood bicarbonate and fall in mean arterial blood pressure.

Resistant starch alters gut microbiome and metabolomic profiles concurrent with amelioration of chronic kidney disease in rats.

Patients and animals with chronic kidney disease (CKD) exhibit profound alterations in the gut environment including shifts in microbial composition, increased fecal pH, and increased blood levels of gut microbe-derived metabolites (xenometabolites). The fermentable dietary fiber high amylose maize-resistant starch type 2 (HAMRS2) has been shown to alter the gut milieu and in CKD rat models leads to markedly improved kidney function. The aim of the present study was to identify specific cecal bacteria and cecal, blood, and urinary metabolites that associate with changes in kidney function to identify potential mechanisms involved with CKD amelioration in response to dietary resistant starch. Male Sprague-Dawley rats with adenine-induced CKD were fed a semipurified low-fiber diet or a high-fiber diet [59% (wt/wt) HAMRS2] for 3 wk (n = 9 rats/group). The cecal microbiome was characterized, and cecal contents, serum, and urine metabolites were analyzed. HAMRS2-fed rats displayed decreased cecal pH, decreased microbial diversity, and an increased Bacteroidetes-to-Firmicutes ratio. Several uremic retention solutes were altered in the cecal contents, serum, and urine, many of which had strong correlations with specific gut bacteria abundances, i.e., serum and urine indoxyl sulfate were reduced by 36% and 66%, respectively, in HAMRS2-fed rats and urine p-cresol was reduced by 47% in HAMRS2-fed rats. Outcomes from this study were coincident with improvements in kidney function indexes and amelioration of CKD outcomes previously reported for these rats, suggesting an important role for microbial-derived factors and gut microbe metabolism in regulating host kidney function.

Lipidomics Biomarkers of Diet-Induced Hyperlipidemia and Its Treatment with Poria cocos.

Hyperlipidemia is a major cause of atherosclerotic cardiovascular disease. Poria cocos (PC) is a medicinal product widely used in Asia. This study was undertaken to define the alterations of lipid metabolites in rats fed a high-fat diet to induce hyperlipidemia and to explore efficacy and mechanism of action of PC in the treatment of diet-induced hyperlipidemia. Plasma samples were then analyzed using UPLC-HDMS. The untreated rats fed a high-fat diet exhibited significant elevation of plasma triglyceride and total and low-density lipoprotein (LDL) cholesterol concentrations. This was associated with marked changes in plasma concentrations of seven fatty acids (palmitic acid, hexadecenoic acid, hexanoylcarnitine, tetracosahexaenoic acid, cervonoyl ethanolamide, 3-hydroxytetradecanoic acid, and 5,6-DHET) and five sterols [cholesterol ester (18:2), cholesterol, hydroxytestosterone, 19-hydroxydeoxycorticosterone, and cholic acid]. These changes represented disorders of biosynthesis and metabolism of the primary bile acids, steroids, and fatty acids and mitochondrial fatty acid elongation pathways in diet-induced hyperlipidemia. Treatment with PC resulted in significant improvements of hyperlipidemia and the associated abnormalities of the lipid metabolites.

Dose-dependent deleterious and salutary actions of the Nrf2 inducer dh404 in chronic kidney disease.

Oxidative stress and inflammation play a central role in the progression and complications of chronic kidney disease (CKD) and are, in part, due to impairment of the Nrf2 system, which regulates the expression of antioxidant and detoxifying molecules. Natural Nrf2-inducing phytochemicals have been shown to ameliorate kidney disease in experimental animals. However, owing to adverse outcomes a clinical trial of a synthetic Nrf2 activator, bardoxolone methyl (BARD), in CKD patients was terminated. BARD activates Nrf2 via covalent modification of reactive cysteine residues in the Nrf2 repressor molecule, Keap1. In addition to Nrf2, Keap1 suppresses IKKB, the positive regulator of NF-κB. Treatment with a BARD analog, dh404, at 5-20mg/kg/day in diabetic obese Zucker rats exacerbates, whereas its use at 2mg/kg/day in 5/6 nephrectomized rats attenuates, CKD progression. We, therefore, hypothesized that deleterious effects of high-dose BARD are mediated by the activation of NF-κB. CKD (5/6 nephrectomized) rats were randomized to receive dh404 (2 or 10mg/kg/day) or vehicle for 12 weeks. The vehicle-treated group exhibited glomerulosclerosis; interstitial fibrosis and inflammation; activation of NF-κB; upregulation of oxidative, inflammatory, and fibrotic pathways; and suppression of Nrf2 activity and its key target gene products. Treatment with low-dose dh404 restored Nrf2 activity and expression of its target genes, attenuated activation of NF-κB and fibrotic pathways, and reduced glomerulosclerosis, interstitial fibrosis, and inflammation. In contrast, treatment with a high dh404 dosage intensified proteinuria, renal dysfunction, and histological abnormalities; amplified upregulation of NF-κB and fibrotic pathways; and suppressed the Nrf2 system. Thus therapy with BARD analogs exerts a dose-dependent dimorphic impact on CKD progression.

Role of Nrf2 dysfunction in uremia-associated intestinal inflammation and epithelial barrier disruption.

BACKGROUND: Gut inflammation is prevalent in chronic kidney disease (CKD) and likely contributes to systemic inflammation via disruption of the epithelial tight junction with subsequent endotoxin and bacterial translocation. AIMS: To study the expression profile of inflammatory and tight junction proteins in the colon from CKD rats compared to healthy controls, and demonstrate the role of Nrf2 (transcription factor nuclear factor erythroid 2-related factor 2) using a potent Nrf2 activator. METHODS: CKD was induced via 5/6 nephrectomy in Sprague-Dawley rats, and dh404 (2 mg/kg/day) was used to study the effects of systemic Nrf2 activation. The experimental groups included sham, CKD and CKD+ dh404 rats. Blood and colon tissues were analyzed after a 10-week study period. RESULTS: Colon from CKD rats showed histological evidence of colitis, depletion of epithelial tight junction proteins, significant reduction of Nrf2 and its measured target gene products (NQO1, catalase, and CuZn SOD), activation of NFkB, and upregulation of pro-inflammatory molecules (COX-2, MCP-1, iNOS, and gp91(phox)). Treatment with dh404 attenuated colonic inflammation, restored Nrf2 activity and levels of NQO1, catalase and CuZn SOD, decreased NFkB and lowered expression of COX-2, MCP-1, iNOS, and gp91(phox). This was associated with restoration of colonic epithelial tight junction proteins (occludin and claudin-1). CONCLUSIONS: CKD rats exhibited colitis, disruption of colonic epithelial tight junction, activation of inflammatory mediators, and impairment of Nrf2 pathway. Treatment with an Nrf2 activator restored Nrf2 activity, attenuated colonic inflammation, and restored epithelial tight junction proteins.