Localization of Diacylglycerol Kinase ζ in the Kidney of Adult Rats: Its Dominant Expression in Collecting Tubules and its Selective Lack in Proximal Tubules / Localización de Diacilglicerol Quinasa ζ en el Riñón de Ratas Adultas: su Expresión Dominante en Túbulos Colectores y su Carencia Selectiva en Túbulos Proximales

SUMMARY: Diacylglycerol kinase (DGK) exerts balancing the intracellular level between two-second messengers, diacylglycerol and phosphatidic acid, by its phosphorylation activity. DGK ζ is often localized in cell nuclei, suggesting its involvement in the regulation of intranuclear activities, including mitosis and apoptosis. The present immunohistochemical study of rat kidneys first revealed no detection levels of DGK ζ -immunoreactivity in nuclei of most proximal tubule epithelia in contrast to its distinct occurrence in cell nuclei of collecting and distal tubules with the former more dominant. This finding suggests that DGK ζ is a key factor regulating vulnerability to acute kidney injury in various renal tubules: its low expression represents the high vulnerability of proximal tubule cells, and its distinct expression does the resistance of collecting and distal tubule cells. In addition, this isozyme was more or less localized in nuclei of cells forming glomeruli as well as in endothelial nuclei of peritubular capillaries and other intrarenal blood vessels, and epithelial nuclei of glomerular capsules (Bowman's capsules) and renal calyces, including intrarenal interstitial cells.

La diacilglicerol quinasa (DGK) ejerce el equilibrio del nivel intracelular entre dos segundos mensajeros, diacilglicerol y ácido fosfatídico, por su actividad de fosforilación. La DGK ζ a menudo se localiza en los núcleos celulares, lo que sugiere su participación en la regulación de las actividades intranucleares, incluidas la mitosis y la apoptosis. El presente estudio inmunohistoquímico en riñones de rata no reveló niveles de detección de inmunorreactividad de DGK ζ en los núcleos de la mayoría de los epitelios de los túbulos proximales, en contraste a la detección en los núcleos celulares de los túbulos colectores y distales, siendo el primero más dominante. Este hallazgo sugiere que DGK ζ es un factor clave que regula la vulnerabilidad a la lesión renal aguda en varios túbulos renales: su baja expresión representa la alta vulnerabilidad de las células del túbulo proximal, y su expresión distinta hace a la resistencia de las células del túbulo colector y distal. Además, esta isoenzima estaba más o menos localizada en los núcleos de las células que forman los glomérulos, así como en los núcleos endoteliales de los capilares peritubulares y otros vasos sanguíneos intrarrenales, y en los núcleos epiteliales de las cápsulas glomerulares (cápsulas de Bowman) y los cálices renales, incluidas las células intersticiales intrarrenales.

Morphometry: assessing direct and indirect methods of measuring the diameters of tubular structures / Morfometría: evaluación de métodos directos e indirectos para medir los diámetros de las estructuras tubulares

SUMMARY: Knowledge of the diameter of a structure or particle is required for stereological calculations. However, there is no consensus on the methodology for its measurement. This study aims to assess the differences between direct and indirect methods of measuring diameter. It is hypothesised that kidneys were removed, fixed, processed, sectioned, and stained. The stained slides were imaged using a digital microscope. The images were processed using the ImageJ software. The diameters of the renal glomeruli and collecting tubules were measured using direct and indirect methods. The measured diameters were analysed using the SPSS software v20. The differences between the measurements were assessed using a Z-test and test of association, and P < 0.05 was considered significant. No significant differences were observed between the diameters of the glomeruli (P = 0.82) and proximal (P = 0.86) and distal (P = 0.55) convoluted tubules as measured via direct and indirect methods. There was a strong positive correlation between the diameters of glomeruli (P = 0.97) and proximal (P = 0.82) and distal (P = 0.93) convoluted tubules measured using the two methods, both of which are convenient, accurate and suitable. The P-values based on these measurements were more than 0.05. Therefore, the study hypothesis was rejected. There was no significant difference between the direct and indirect methods of measuring diameter, and the null hypothesis was rejected; thus, both methods can be applied either independently or jointly.

RESUMEN: Se requiere el conocimiento del diámetro de una estructura o partícula para los cálculos estereológicos. Sin embargo, no existe consenso sobre la metodología para su medición. Este estudio tuvo como objetivo evaluar las diferencias entre los métodos directos e indirectos de medición del diámetro de una estructura. Riñones de ratas Wistar fueron extirpados, fijados, procesados y seccionados, y luego se tiñeron con HE. Se tomaron imágenes de las muestras teñidas usando un microscopio digital. Las imágenes fueron procesadas utilizando el software ImageJ. Los diámetros de los glomérulos renales y túbulos colectores se midieron por métodos directos e indirectos. Los diámetros medidos se analizaron utilizando el software SPSS v20. Las diferencias entre las medidas se evaluaron mediante una prueba Z y una prueba de asociación, y se consideró significativa P < 0,05. No se observaron diferencias significativas entre los diámetros de los glomérulos (P = 0,82) y túbulos contorneados proximales (P = 0,86) y distales (P = 0,55) medidos mediante métodos directos e indirectos. Hubo una fuerte correlación positiva entre los diámetros de los glomérulos (P = 0,97) y los túbulos contorneados proximales (P = 0,82) y distales (P = 0,93) medidos con los dos métodos, ambos convenientes, precisos y adecuados. Los valores P basados en estas mediciones fueron superiores a 0,05. Por lo tanto, se rechazó la hipótesis del estudio. No hubo diferencia significativa entre los métodos directo e indirecto de medición del diámetro, y se rechazó la hipótesis nula; por lo tanto, ambos métodos se pueden aplicar de forma independiente o conjunta.

Acetaminophen induces alterations to the renal tubular ultrastructure in a rat model of acute nephrotoxicity protected by resveratrol and quercetin / El acetaminofeno induce alteraciones en la ultraestructura tubular renal en un modelo de rata con nefrotoxicidad aguda protegida por resveratrol y quercetina

Acetaminophen (also called paracetamol, or APAP) induced nephrotoxicity is reported after accidental or intentional ingestion of an overdose of the drug. Renal tubular ultrastructural alterations induced by APAP overdose associated with the induction of biomarkers of kidney injury have not been investigated before. Also, we investigated whether the combined polyphenolic anti-inflammatory and antioxidants agents, resveratrol (RES) and quercetin (QUR) can protect against APAP-induced acute kidney injury. The model group of rats received a single dose of APAP (2 g/kg), whereas the protective group of rats was pre-treated for 7 days with combined doses of RES (30 mg/kg) and QUR (50 mg/kg) before being given a single dose of APAP. All rats were then sacrificed one day post APAP ingestion. Harvested kidney tissues were prepared for transmission electron microscopy (TEM) staining and blood samples were assayed for urea, creatinine, and biomarkers of inflammation and oxidative stress. TEM images and blood chemistry analysis showed that APAP overdose induced kidney damage as demonstrated by substantial alterations to the proximal convoluted tubule ultrastructure, and a significant (p<0.05) increase in urea, creatinine, tumor necrosis factor-alpha (TNF-a), and malondialdehyde (MDA) blood levels, which were protected by RES+QUR. These findings indicate that APAP induces alterations to the renal tubular ultrastructure, which is inhibited by resveratrol plus quercetin, which also decreases blood levels of kidney injury biomarkers.

El objetivo de este trabajo fue estudiar la nefrotoxicidad inducida por acetaminofeno (también llamado paracetamol o APAP) después de la ingestión accidental o intencional de una sobredosis de la droga. Las alteraciones ultraestructurales tubulares renales inducidas por sobredosis de APAP asociadas con la inducción de biomarcadores de daño renal no se han investigado. Además, estudiamos si los agentes combinados antiinflamatorios y antioxidantes polifenólicos, el resveratrol (RES) y la quercetina (QUR) pueden proteger contra la lesión renal aguda inducida por APAP. El grupo modelo de ratas recibió una dosis única de APAP (2 g / kg), mientras que el grupo protector de ratas se trató previamente durante 7 días con dosis combinadas de RES (30 mg / kg) y QUR (50 mg / kg) antes de recibir una dosis única de APAP. Todas las ratas se sacrificaron un día después de la ingestión de APAP. Los tejidos renales fueron preparados para el análisis a través de la microscopía electrónica de transmisión (MET). En las muestras de sangre se determinaron la urea, creatinina y los biomarcadores de inflamación y estrés oxidativo. Las imágenes MET y el análisis químico de la sangre mostraron que la sobredosis de APAP inducía daño renal, como lo demuestran las alteraciones sustanciales en la ultraestructura del túbulo contorneado proximal, y además, de un aumento significativo (p <0,05) de la urea, creatinina, factor de necrosis tumoral alfa y niveles sanguíneos de malondialdehído, protegidos por RES + QUR. Estos hallazgos indican que APAP induce alteraciones en la ultraestructura tubular renal, inhibida por el resveratrol más quercetina, que también disminuye los niveles sanguíneos de biomarcadores de daño renal.

Rare inherited kidney diseases: an evolving field in Nephrology / Doenças renais hereditárias raras: um campo em evolução na Nefrologia

Abstract There are more than 150 different rare genetic kidney diseases. They can be classified according to diagnostic findings as (i) disorders of growth and structure, (ii) glomerular diseases, (iii) tubular, and (iv) metabolic diseases. In recent years, there has been a shift of paradigm in this field. Molecular testing has become more accessible, our understanding of the underlying pathophysiologic mechanisms of these diseases has evolved, and new therapeutic strategies have become more available. Therefore, the role of nephrologists has progressively shifted from a mere spectator to an active player, part of a multidisciplinary team in the diagnosis and treatment of these disorders. This article provides an overview of the recent advances in rare hereditary kidney disorders by discussing the genetic aspects, clinical manifestations, diagnostic, and therapeutic approaches of some of these disorders, named familial focal and segmental glomerulosclerosis, tuberous sclerosis complex, Fabry nephropathy, and MYH-9 related disorder.

Resumo As doenças renais genéticas raras compreendem mais de 150 desordens. Elas podem ser classificadas segundo achados diagnósticos como (i) distúrbios do crescimento e estrutura, (ii) doenças glomerulares, (iii) tubulares e (iv) metabólicas. Nos últimos anos, houve uma mudança de paradigma nesse campo. Os testes moleculares tornaram-se mais acessíveis, nossa compreensão sobre os mecanismos fisiopatológicos subjacentes a essas doenças evoluiu e novas estratégias terapêuticas foram propostas. Portanto, o papel do nefrologista mudou progressivamente de mero espectador a participante ativo, parte de uma equipe multidisciplinar, no diagnóstico e tratamento desses distúrbios. O presente artigo oferece um panorama geral dos recentes avanços a respeito dos distúrbios renais hereditários raros, discutindo aspectos genéticos, manifestações clínicas e abordagens diagnósticas e terapêuticas de alguns desses distúrbios, mais especificamente a glomeruloesclerose segmentar e focal familiar, complexo da esclerose tuberosa, nefropatia de Fabry e doença relacionada ao MYH9.

Urine microscopy as a biomarker of Acute Kidney Injury following cardiac surgery with cardiopulmonary bypass / Microscopia urinária como biomarcador de lesão renal aguda após cirurgia cardíaca com circulação extracorpórea

Abstract Introduction: Acute kidney injury (AKI) occurs in about 22% of the patients undergoing cardiac surgery and 2.3% requires renal replacement therapy (RRT). The current diagnostic criteria for AKI by increased serum creatinine levels have limitations and new biomarkers are being tested. Urine sediment may be considered a biomarker and it can help to differentiate pre-renal (functional) from renal (intrinsic) AKI. Aims: To investigate the microscopic urinalysis in the AKI diagnosis in patients undergoing cardiac surgery with cardiopulmonary bypass. Methods: One hundred and fourteen patients, mean age 62.3 years, 67.5 % male, with creatinine 0.91 mg/dL (SD 0.22) had a urine sample examined in the first 24 h after the surgery. We looked for renal tubular epithelial cells (RTEC) and granular casts (GC) and associated the results with AKI development as defined by KDIGO criteria. Results: Twenty three patients (20.17 %) developed AKI according to the serum creatinine criterion and 76 (66.67 %) by the urine output criterion. Four patients required RRT. Mortality was 3.51 %. The use of urine creatinine criterion to predict AKI showed a sensitivity of 34.78 % and specificity of 86.81 %, positive likelihood ratio of 2.64 and negative likelihood ratio of 0.75, AUC-ROC of 0.584 (95%CI: 0.445-0.723). For the urine output criterion sensitivity was 23.68 % and specificity 92.11 %, AUC-ROC was 0.573 (95%CI: 0.465-0.680). Conclusion: RTEC and GC in urine sample detected by microscopy is a highly specific biomarker for early AKI diagnosis after cardiac surgery.

Resumo Introdução: Lesão renal aguda (LRA) ocorre em cerca de 22% dos pacientes submetidos a cirurgia cardíaca e 2,3% necessitam de terapia renal substitutiva (TRS). Os atuais critérios diagnósticos para LRA fundamentados no aumento dos níveis de creatinina sérica apresentam limitações e novos biomarcadores estão sendo testados. O sedimento urinário é um biomarcador que pode ajudar a diferenciar a LRA pré-renal (funcional) da LRA renal (intrínseca). Objetivos: Investigar a urinálise microscópica no diagnóstico de LRA em pacientes submetidos a cirurgia cardíaca com circulação extracorpórea. Métodos: Um total de 114 pacientes com idade média de 62,3 anos, 67,5% do sexo masculino e níveis médios de creatinina de 0,91 mg/dL (DP 0,22) tiveram amostras de urina examinadas nas primeiras 24 horas após a cirurgia. A identificação de células epiteliais tubulares renais (CETR) e cilindros granulares (CG) foi associada a desfechos de desenvolvimento de LRA conforme os critérios do KDIGO. Resultados: Vinte e três pacientes (20,17%) desenvolveram LRA pelo critério de creatinina sérica e 76 (66,67%) pelo critério de diurese. Quatro pacientes necessitaram de TRS. A mortalidade foi de 3,51%. O uso da creatinina urinária como critério preditivo para LRA mostrou sensibilidade de 34,78% e especificidade de 86,81%; razão de verossimilhança positiva de 2,64 e razão de verossimilhança negativa de 0,75; e ASC-COR de 0,584 (IC 95%: 0,445-0,723). Para o critério de diurese, a sensibilidade foi de 23,68% e a especificidade 92,11%; a ASC-COR foi 0,573 (IC 95%: 0,465-0,680). Conclusão: A identificação de CETR e CG em amostras de urina por microscopia representa um biomarcador altamente específico para o diagnóstico precoce de LRA após cirurgia cardíaca.

Drug-induced nephrotoxicity

Drugs are a common cause of acute and chronic kidney disease and contribute to patient morbidity and increased healthcare utilization. Drug-induced nephrotoxicity is approximately 14% to 26% in adults and tends to increase among certain patients and/or with complex clinical conditions. Unfortunately, apart from conservative management, including drug withdrawal, no effective treatment is known for this condition. Therefore, in order to reduce the frequency of drug-induced nephrotoxicity, early recognition of renal toxicity and appropriate prevention strategies, such as understanding the exact mechanisms of renal injury, patient and drug-related risk factors, and preemptive measures are needed. In this review, we will present the mechanisms of drug-induced nephrotoxicity and general preventive strategies for clinical physicians.

Simultaneous use of oxalate-degrading bacteria and herbal extract to reduce the urinary oxalate in a rat model: A new strategy

ABSTRACT Objective: Urinary stones with oxalate composition can cause kidney failure. Recent findings evidenced that probiotics are effective in reducing oxalate absorption in these subjects based on their high colonic absorption levels at baseline. The purpose of this study was to evaluate the effect of the simultaneous use of oxalate-degrading bacteria, Urtica dioica and T. terrestris extract in reducing urinary oxalate. Materials and Methods: Anti-urolithiatic activity of Urtica dioica and T. terrestris extract and probiotic by using ethylene glycol induced rat model. In this study, 4 strains of Lactobacillus and 2 strains of Bifidobacterium and also 2 strains of L. paracasei (that showed high power in oxalate degrading in culture media) were used. Male Wistar rats were divided into four groups (n=6). The rats of group-I received normal diet (positive control group) and groups-II (negative control group), III, IV rats received diet containing ethylene glycol (3%) for 30 days. Groups III rats received Urtica dioica and T. terrestris extract. Groups IV rats received extracts + probiotic for 30 days. Findings: The results show that the use of herbal extracts (Urtica dioica and T. terrestris) reduced the level of urinary oxalate and other parameters of urine and serum. Also, the accumulation of calcium oxalate crystals in the kidney tissue was significantly reduced. Conclusion: Considering that the formation of calcium oxalate crystals can cause inflammation and tissue damage in the kidney, the use of herbal extracts with oxalate degrading bacteria can be a new therapeutic approach to preventing the formation of kidney stones.

Renal histological alterations induced by acute exposure of titanium dioxide nanoparticles / Alteraciones histológicas renales inducidas por la exposición aguda de nanopartículas de dióxido de titanio

SUMMARY: Titanium dioxide nanoparticles (TiO2 NPs) are widely used in many commercial products, nanomedicine, agriculture, personal care products, different industries and pharmaceutical preparations with potential risk in human health and the environment. The current work was conducted to investigate the renal damage that might be induced by the acute toxicity TiO2 NPs. A total of 40 healthy male adult Wistar albino rats (Rattus norvegicus) were exposed to TiO2 NPs (126, 252, 378 mg/kg bw) for 24 and 48 h. Fresh portions of the kidneys from each rat were processed for histological and histochemical alterations. In comparison with respective control rats, exposure to TiO2 NPs has marked the following glomerular, tubular and interstitial alterations including the followings: glomerular congestion, Bowman's capsule swelling and dilatation, inflamed glomeruli, renal tubules cloudy swelling, karyorrhexis, karyolysis, infiltration of inflammatory cells, congestion, necrosis, hydropic degeneration, dilatation and congestion of blood vessels, hyaline droplets and hyaline casts precipitation, interstitial edema and fibrosis. From the findings of the current work one may conclude that TiO2 NPs are capable of inducing kidney damage with more insulation in the cortex and the proximal convoluted tubules than the medulla and the distal ones respectively. In addition, it might be concluded that renal damage induced by these nanomaterials is dose and duration of exposure dependent. Further hematological, biochemical, immunohistochemical, and ultra-structural studies are recommended.

RESUMEN: Las nanopartículas de dióxido de titanio (TiO2 NP) se usan ampliamente en muchos productos comerciales, nanomedicina, agricultura, productos para el cuidado personal, diferentes industrias y preparaciones farmacéuticas con riesgo potencial para la salud humana y el medio ambiente. El trabajo actual se realizó para investigar el daño renal que podría ser inducido por la toxicidad aguda NP de TiO2. Un total de 40 ratas Wistar albinas adultas sanas (Rattus norvegicus) fueron expuestas a TiO2 NP (126, 252, 378 mg / kg de peso corporal) durante 24 y 48 h. Las muestras de los riñones de las ratas se procesaron para estudios histológicos e histoquímicos. En comparación con las ratas control, la exposición de las ratas a TiO2 NP presentaron las siguientes alteraciones glomerulares, tubulares e intersticiales: congestión glomerular, dilatación de la cápsula de Bowman, inflamación glomerular, túbulos renales aumentados, cariorrexis, cariólisis, infiltración de células inflamatorias, congestión, necrosis, degeneración hidrópica, dilatación y congestión de vasos sanguíneos, gotas y precipitaciones hialina, edema intersticial y fibrosis. A partir de los hallazgos del trabajo actual, se puede concluir que las NP de TiO 2 son capaces de inducir daño renal con más aislamiento en la corteza y en los túbulos contorneados proximales que en la médula y los túbulos contorneados distales, respectivamente. Además, se podría concluir que el daño renal inducido por estos nanomateriales depende de la dosis y la duración de la exposición. Se recomiendan estudios adicionales hematológicos, bioquímicos, inmunohistoquímicos y ultraestructurales.

Study on acute kidney injury model induced by renal ischemia-reperfusion in rats / 中国中药杂志

In this study,in-depth systematic evaluation of rat of acute kidney injury(AKI) caused by renal arteriovenous ligation was conducted to better master and apply this model for drug research. Male SD rats of 2-3 months old were employed in this study.The left kidney was removed,and the right kidney received ligation for 40 min and reperfusion for 24 h. Serum creatinine(Crea),urea nitrogen(BUN) and the renal tissue sections were assayed as the basic indicators to evaluate their renal function. The mRNA expression of inflammatory necrosis factors and apoptotic factors was used to evaluate the mechanism of molecular pathophysiological changes. The results showed that the serum Crea and BUN caused by ligation of both renal arteries and veins were significantly higher than those of rats with renal artery ligation. After renal arteriovenous ligation for 40 min and reperfusion for 24 h in rats,the serum Crea of the rats varied from less than 100 μmol·L-1 to more than 430 μmol·L-1. Among them,5 rats showed less than 100 μmol·L-1 serum Crea,20 rats with 100-200 μmol·L-1 serum Crea and 12 rats with more than 430 μmol·L-1. Rats with serum Crea between 300-430 μmol·L-1 accounted for 66.3%(122/184) of the total number of the experiment rats. After 72 h reperfusion,serum Crea in the group of Crea 370-430 μmol·L-1 continued to increase,while the serum Crea in the group of Crea 200-300 μmol·L-1 and the group of Crea 300-370 μmol·L-1 recovered quickly. No matter serum Crea was elevated or decreased,the renal tubules showed pathological changes such as vacuolar degeneration or even necrosis. The mRNA expression levels of Toll-like receptor(TLR4),tumor necrosis factor(TNF-α) and interleukin(IL-6) in renal tissueswere significantly up-regulated,and the effect was most obvious in the group of serum Crea 370-430 μmol·L-1. The study indicated that the model for AKI caused by renal arteriovenous ligation and reperfusion is easy to operate,and the serum Crea and BUN have the characteristics of continuous increase,beneficial to the observation of drug effects. This acute kidney injury is mainly related to the pathophysiological response of inflammatory necrosis.

Blocking pannexin-1 alleviates cisplatin-induced acute kidney injury in mice by reducing renal inflammatory cell infiltration / 南方医科大学学报

OBJECTIVE@#To investigate the effect of blocking pannexin-1 against acute kidney injury induced by cisplatin.@*METHODS@#Twenty-six male C57BL/6 mice aged 6-8 weeks were randomly divided into control group, cisplatin model (Cis) group and cisplatin + carbenoxolone treatment group (Cis + CBX). In Cis group and Cis + CBX group, the mice were injected intraperitoneally with 20 mg/kg of cisplatin and with CBX (20 mg/kg) at 30 min before and 24 and 48 h after cisplatin inhjection, respectively. All the mice were sacrificed at 72 h after cisplatin injection, and plasma and kidney samples were collected for testing mRNA and protein expression levels of pannexin-1 in the renal tissue using RT-qPCR and Western blotting and for detecting plasma creatinine and BUN levels; the pathological changes in the renal tissues were observed using Periodic Acid-Schiff staining. The expression of kidney injury molecule 1 (KIM-1) was examined using immunohistochemistry and the mRNA expressions of KIM-1 and neutrophil gelatinase- related lipid transport protein (NGAL) were detected by RT-qPCR to evaluate the injuries of the renal tubules. The infiltration of F4/80-positive macrophages and CD4-positive T cells were observed by immunofluorescence. In the experiment, human proximal tubule epithelial cell line HK-2 was stimulated with 50 μmol/L cisplatin to establish a cell model of acute kidney injury, and the mRNA and protein expressions of pannexin-1 were detected by RT-qPCR and Western blotting at 4, 6, 12, 18 and 24 h after the stimulation.@*RESULTS@#Compared with the control mice, the cisplatin-treated mice showed significantly up-regulated protein levels ( < 0.05) and mRNA levels ( < 0.005) of pannexin-1 in the kidney tissue. Cisplatin stimulation also caused significant increases in the protein levels ( < 0.005) and mRNA levels ( < 0.005) of pannexin-1 in cultured HK-2 cells. Compared with cisplatin-treated mice, the mice treated with both cisplatin and the pannexin-1 inhibitor CBX showed obviously lessened kidney pathologies and milder renal tubular injuries with significantly reduced plasma BUN and Scr levels ( < 0.01), expressions of KIM-1 and NGAL in the kidney ( < 0.05), and infiltration of F4/80-positive macrophages ( < 0.01) and CD4- positive T cells ( < 0.05) in the kidney tissues.@*CONCLUSIONS@#In cisplatin induced acute kidney injury mice model, Pannexin-1 expression is up-regulated in the kidneys tissue, and blocking pannexin-1 alleviates the acute kidney injury reducing renal inflammatory cell infiltration.

Effect of enalapril on apoptosis of renal tubular epithelial cells in renal interstitial fibrosis in rats / 中南大学学报(医学版)

To observe the effect of enalapril on the apoptosis of renal tubular epithelial cells in renal interstitial fibrosis rats and to explore the mechanism of enalapril on renal interstitial fibrosis.
 Methods: Twenty-four SD male rats were randomly divided into a sham operation group, a model group and an enalapril group (n=8 in each group). The rats in the model group and the enalapril group underwent the operation of left urethral obstruction to establish the animal model of unilateral urethral obstruction (UUO). Fourteen days later after the operation, all rats were sacrificed and their obstructed kidneys were collected for HE and Masson staining to observe the pathological change of renal tissues. Terminal deoxynucleotidyl transferase-mediated (dUTP) nick end-labeling (TUNEL) staining was used to detect the apoptosis of renal tubular epithelial cells. Immunohistochemistry and Western blotting were used to detect the protein expression of Fas-associated death domain (FADD), apoptotic protease activating factor-1 (APAF-1) and C/EBP homologous protein (CHOP).
 Results: Compared with the sham operation group, the renal interstitial injury index and renal interstitial fibrosis index were significantly increased in the model group (P<0.05). Compared with the model group, the renal interstitial injury index and renal interstitial fibrosis index were both significantly decreased in the enalapril group (P<0.05). Compared with the sham group, the apoptosis rate of renal tubular epithelial cells was increased in the model group (P<0.05); compared with the model group, the apoptosis rate of renal tubular epithelial cells was significantly reduced in the enalapril group (P<0.05). The protein levels of FADD, APAF-1 and CHOP in the model group were significantly elevated than those in the sham group (all P<0.05), which were reversed in presence of enalapril (all P<0.05). 
 Conclusion: Enalapril can alleviate renal interstitial fibrosis through inhibiting apoptosis of renal tubular epithelial cells in UUO rats.

Asociación entre hallazgos bucales y enfermedad renal en pacientes pediátricos en Venezuela / Association between oral findings and renal disease among pediatric patients in Venezuela

La cavidad oral puede mostrar signos clínicos de enfermedades renales que pasan desapercibidos. El objetivo de este estudio fue evaluar la asociación entre defectos del esmalte (DDE), cálculo dental, bajo peso, baja talla y el diagnóstico de disfunciones tubulares simples o tubulopatías entre 256 pacientes pediátricos (160 con tubulopatías simples y 96 controles sanos) en un importante hospital urbano de Valencia, Venezuela. La frecuencia de DDE en el grupo con tubulopatías fue de 56.25% y en controles de 29.2%, cálculo dental 26.9% y 10.4%, respectivamente. Los modelos de regresión logística revelaron la presencia de DDE (p = 0.000), cálculo dental (p = 0.002), bajo peso (p = 0.000) y baja talla (p = 0.000); cada una de estas características por separado presentó una asociación estadísticamente significativa con tubulopatías. Los niños con DDE tienen 2.7 más posibilidades de afección renal que los que no presentan DDE (Wald = 11.263 y p-valor = 0.001), también los pacientes con cálculo dental son 2.3 veces más propensos a padecer tubulopatías que los que no lo tienen (Wald = 4.076 y p-valor = 0.043) y los niños con bajo peso tienen 53.7% más probabilidad de presentar disfunción tubular simple (Wald = 4.751 y p-valor = 0.029). De allí que se puede afi rmar que la ocurrencia de tubulopatías tiene una asociación estadísticamente significativa con la presencia de DDE, cálculo dental y bajo peso. Estos datos pueden contribuir a que en la consulta odontopediátrica se aumente el número de referencia de niños con tubulopatías por la asociación de las variables mencionadas (AU)

The oral cavity may show clinical signs of renal diseases that go unnoticed. The aim of this study was to evaluate the association between enamel dental defects (EDD), dental calculus, low weight, low height and the diagnosis of simple tubular dysfunctions or tubulopathies among 256 pediatric patients (160 with simple tubulopathies and 96 healthy controls) in an important urban hospital of Valencia, Venezuela. The frequency of EDD in the group with tubulopathies was 56.25% and in controls 29.2%, dental calculus 26.9%, and 10.4%, respectively. The logistic regression models re-vealed that the presence of DDE (p = 0.000), dental calculus (p = 0.002), low weight (p = 0.000) and low size (p = 0.000), each of these characteristics Patients presented a statistically signifi cant association with the presence of tubulopathies. Children with EDD are 2.7 times more likely to have renal disease than those without EDD (Wald = 11.263 and p-value = 0.001); patients with dental calculus are 2.3 times more likely to have tubulopathies than (Wald = 4.076 and p-value = 0.043) and children with low weight were 53.7% more likely to have simple tubular dysfunction (Wald = 4.751 and p-value = 0.029). Hence, it can be affi rmed that the occurrence of tubulopathies has a statistically signifi cant association with the presence of DDE, dental calculus, and low weight. These data may contribute to the increase in the reference number of children with tubulopathies by the association of the mentioned variables (AU)

Ginsenoside Rg1 protects human renal tubular epithelial cells from lipopolysaccharide-induced apoptosis and inflammation damage

Ginsenoside Rg1, one of the most notable active components of Panax ginseng, has been widely reported to exert anti-inflammatory actions. This study aimed to reveal whether ginsenoside Rg1 also exhibits beneficial roles against lipopolysaccharide (LPS)-induced apoptosis and inflammation in human renal tubular epithelial cells, and to evaluate the potential role of the component on tubulointerstitial nephritis treatment. HK-2 cells were treated with various doses of ginsenoside Rg1 (0, 50, 100, 150, and 200 μM) in the absence or presence of 5 μg/mL LPS. Thereafter, CCK-8 assay, flow cytometry, western blot, migration assay, reactive oxygen species (ROS) assay, and ELISA were carried out to respectively assess cell viability, apoptosis, migration, ROS activity, and the release of inflammatory cytokines. As a result, ginsenoside Rg1 protected HK-2 cells from LPS-induced injury, as cell viability was increased, cell apoptosis was decreased, and the release of MCP-1, IL-1β, IL-6, and TNF-α was reduced. Ginsenoside Rg1 functioned to HK-2 cells in a dose-dependent manner, and the 150 μM dose exhibited the most protective functions. Ginsenoside Rg1 had no significant impact on cell migration and ROS activity, while it alleviated LPS-induced ROS release and migration impairment. Furthermore, the down-regulations of p-PI3K, p-AKT, and up-regulations of PTEN, p-IκBα, p-p65, Bcl-3 induced by LPS were recovered to some extent after ginsenoside Rg1 treatment. In conclusion, ginsenoside Rg1 protects HK-2 cells against LPS-induced inflammation and apoptosis via activation of the PI3K/AKT pathway and suppression of NF-κB pathway.

Glycated Albumin Is a More Useful Glycation Index than HbA1c for Reflecting Renal Tubulopathy in Subjects with Early Diabetic Kidney Disease

BACKGROUND: The aim of this study was to investigate which glycemic parameters better reflect urinary N-acetyl-β-D-glucosaminidase (uNAG) abnormality, a marker for renal tubulopathy, in subjects with type 2 diabetes mellitus (T2DM) subjects with normoalbuminuria and a normal estimated glomerular filtration rate (eGFR). METHODS: We classified 1,061 participants with T2DM into two groups according to uNAG level—normal vs. high (>5.8 U/g creatinine)—and measured their biochemical parameters. RESULTS: Subjects with high uNAG level had significantly higher levels of fasting and stimulated glucose, glycated albumin (GA), and glycosylated hemoglobin (HbA1c) and lower levels of homeostasis model assessment of β-cell compared with subjects with normal uNAG level. Multiple linear regression analyses showed that uNAG was significantly associated with GA (standardized β coefficient [β]=0.213, P=0.016), but not with HbA1c (β=−0.137, P=0.096) or stimulated glucose (β=0.095, P=0.140) after adjusting confounding factors. In receiver operating characteristic analysis, the value of the area under the curve (AUC) for renal tubular injury of GA was significantly higher (AUC=0.634; 95% confidence interval [CI], 0.646 to 0.899) than those for HbA1c (AUC=0.598; 95% CI, 0.553 to 0.640), stimulated glucose (AUC=0.594; 95% CI, 0.552 to 0.636), or fasting glucose (AUC=0.558; 95% CI, 0.515 to 0.600). The optimal GA cutoff point for renal tubular damage was 17.55% (sensitivity 59%, specificity 62%). CONCLUSION: GA is a more useful glycation index than HbA1c for reflecting renal tubulopathy in subjects with T2DM with normoalbuminuria and normal eGFR.

The function and regulation of basolateral Kir4.1 and Kir4.1/Kir5.1 in renal tubules / 生理学报

Basolateral inwardly-rectifying K channels (Kir) play an important role in the control of resting membrane potential and transepithelial voltage, thereby modulating water and electrolyte transport in the distal part of nephron. Kir4.1 and Kir4.1/Kir5.1 heterotetramer are abundantly expressed in the basolateral membrane of late thick ascending limb (TAL), distal convoluted tubule (DCT), connecting tubule (CNT) and cortical collecting duct (CCD). Loss-of-function mutations in KCNJ10 cause EAST/SeSAME syndrome in humans associated with epilepsy, ataxia, sensorineural deafness and water-electrolyte metabolism imbalance, which is characterized by salt wasting, hypomagnesaemia, hypokalaemia and metabolic alkalosis. In contrast, mice lacking Kir5.1 have severe renal phenotype apart from hypokalaemia such as high chlorine metabolic acidosis and hypercalcinuria. The genetic knockout or functional inhibition of Kir4.1 suppresses Na-Cl cotransporter (NCC) expression and activity in the DCT. However, the downregulation of Kir4.1 increases epithelial Na channel (ENaC) expression in the collecting duct. Recently, factors regulating expression and activity of Kir4.1 and Kir4.1/Kir5.1 were identified, such as cell acidification, dopamine, insulin and insulin-like growth factor-1. The involved mechanisms include PKC, PI3K, Src family protein tyrosine kinases and WNK-SPAK signal transduction pathways. Here we review the progress of renal tubule basolateral Kir, and mainly discuss the function and regulation of Kir4.1 and Kir4.1/Kir5.1.

Evaluation of TGF-beta1 and MCP-1 expression and tubulointerstitial fibrosis in children with Henoch-Schönlein purpura nephritis and IgA nephropathy: A clinical correlation

OBJECTIVES: Henoch-Schönlein purpura nephritis and immunoglobulin A nephropathy are two diseases with similar clinical presentations but very different prognoses. Transforming growth factor β1 and monocyte chemoattractant protein-1 have been associated with the development of tissue fibrosis. We examined the development of tubulointerstitial fibrosis and its relationship with Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in these patients. METHODS: Renal tissue samples were collected by renal biopsy from 50 children with Henoch-Schönlein purpura nephritis and 50 children with immunoglobulin A nephropathy. Hematoxylin and eosin and Masson's trichrome-stained tissues were examined using light microscopy. Tubulointerstitial fibrosis was graded using the method described by Bohle et al. (1). The immunohistochemical detection of Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was correlated with the tubulointerstitial fibrosis grade. Clinical Trial registration number: ZJCH-2012-0105. RESULTS: Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in the renal tissues was significantly greater in the patients with immunoglobulin A nephropathy than in the patients with Henoch-Schönlein purpura nephritis (both p<0.001). The immunoglobulin A nephropathy patients had a higher tubulointerstitial fibrosis grade than the Henoch-Schönlein purpura nephritis patients (p<0.001). The tubulointerstitial fibrosis grade was in accordance with the Transforming growth factor β1 and monocyte chemoattractant protein-1 expression levels in both diseases (both p<0.001). CONCLUSION: Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was associated with the development of immunoglobulin A nephropathy and Henoch-Schönlein purpura nephritis. Further studies are needed to better evaluate this association.

Huaiqihuang Granules () reduce proteinuria by enhancing nephrin expression and regulating necrosis factor κB signaling pathway in adriamycin-induced nephropathy / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of Huaiqihuang Granules (, HQH), a mixture of Chinese herbs including Trametes robiniophila Murr, Fructus Lycii and Polygonatum sibiricum, on adriamycininduced nephropathy (ADRN) in rats and its underlying mechanisms.</p><p><b>METHODS</b>Rats with ADRN were divided into four groups: the sham group, the model group (distilled water), the low-dose HQH-treated (2 g/kg) group, and the high-dose HQH-treated (4 g/kg) group. Body weight and 24-h urinary protein (Upro) were checked every week. After 5-week intervention, at the end of the study, the rats were sacrificed and blood samples were collected for examination of biochemical parameters, including glomerular morphological makers, podocyte shape, cellular apoptosis, expressions of nephrin, inflammatory and apoptosis markers.</p><p><b>RESULTS</b>HQH ameliorated the rat's general status, proteinuria, renal morphological appearance and glomerulosclerosis. The decreased expression of nephrin in ADRN rats was increased by HQH, as well as the impaired podocyte foot process fusion. Cytosolic levels of p65 and inhibitor of nuclear factor κBα (IκBα) were decreased in ADRN rats, and recovered by the treatment of HQH. Consistently, the induced expression of tumor necrosis factor α (TNF-α), phosphorylated nuclear factor κB p65 (p-NFκB p65) and IκBα in ADRN were markedly suppressed by HQH. In addition, induction of Bax, cleaved caspase-3 and cytochrome C in ADRN rats were suppressed by HQH, indicating the amelioration of apoptosis.</p><p><b>CONCLUSION</b>HQH could ameliorate renal impairments in ADRN rats by increasing nephrin expression, inhibiting NF-κB signaling pathway via the down-regulation of p-NF-κB p65 and p-IκBα, and suppression of glomerular and tubular apoptosis.</p>

Diagnóstico de infección por VIH por el hallazgo incidental de alteraciones ultraestructurales en una biopsia renal: Report of one case / Ultrastructural alterations in renal biopsy leading to the diagnosis of HIV infection

HIV infection has different clinical presentations. We report a 21-year-old male with longstanding isolated microscopic hematuria attributed to thin glomerular basement membrane disease, who after 15 years of follow-up presented with significant proteinuria. A kidney biopsy was performed, revealing the presence of tubulo-reticular inclusions in the glomerular endothelial cells. This finding led to suspect an HIV infection, which was verified. Antiretroviral therapy, angiotensin-converting enzyme and angiotensin II receptor blockers were prescribed. At 6 years of diagnosis the patient is asymptomatic and has normal kidney function. Microscopic hematuria and low level proteinuria persists.

Serum concentrations and renal expressions of IL-1 and TNF-a early after hemorrhage in rats under the effect of glibenclamide

ABSTRACT PURPOSE: To investigate changes in the serum concentration and renal expression of IL-1 and TNF-α cytokines in rats that received sevoflurane and glibenclamide prior to hemorrhage. METHODS: Two groups of sevoflurane-anesthetized Wistar rats (n=10): G1 (control) and G2 (glibenclamide, 1 µg/g i.v.); hemorrhage of 30% blood volume (10% every 10 min), with replacement using Ringer solution, 5 ml/kg/h. Serum concentrations of IL-1 and TNF-α were studied in the first hemorrhage (T1) and 50 min later (T2), renal expression, at T2. RESULTS: In serum, G1 TNF-α (pg/mL) was T1=178.6±33.5, T2=509.2±118.8 (p<0.05); IL-1 (pg/mL) was T1=148.8±31.3, T2=322.6±115.4 (p<0.05); in G2, TNF-α was T1=486.2±83.6, T2=261.8±79.5 (p<0.05); IL-1 was T1=347.0±72.0, T2= 327.3±90.9 (p>0.05). The expression of TNF-α and IL-1 in the glomerular and tubular cells was significantly higher in the G2 group. CONCLUSIONS: Hemorrhage and glibenclamide elevated TNF-α and IL-1 concentrations in serum and kidneys. High levels of TNF-α already present before the hemorrhage in the glibenclamide group may have attenuated the damages found in the kidneys after the ischemia event.

Carbon monoxide inhibits the nuclear-cytoplasmic translocation of HMGB1 in an in vitro oxidative stress injury model of mouse renal tubular epithelial cells / 华中科技大学学报（医学）（英德文版）

Carbon monoxide (CO), as a vital small molecule in signaling pathways, is found to be involved in ischemia-reperfusion injury (IRI) in renal transplantation. CO-releasing molecule-2 (CORM-2), a CO-releasing molecule, is a type of metal carbonyl complexes which can quickly release CO in vivo. In this study, an in vitro oxidative stress injury model was established to examine the effect of CORM-2 pretreatment on the nuclear-cytoplasmic translocation of high mobility group box 1 protein (HMGB1) in mouse primary renal proximal tubular epithelial cells (RPTECs). Immunofluorescence staining showed that HMGB1 in the medium- and CORM-2-treated groups was predominantly localized in the nucleus of the cells, whereas higher amounts of HMGB1 translocated to the cytoplasm in the HO- and inactive CORM-2 (iCORM-2)-treated groups. Western blotting of HMGB1 showed that the total amounts of cytoplasmic HMGB1 in the HO-treated (0.59±0.27) and iCORM-2-treated (0.57±0.22) groups were markedly higher than those in the medium-treated (0.19±0.05) and CORM-2-treated (0.21±0.10) groups (P<0.05). Co-immunoprecipitation showed that the levels of acetylated HMGB1 in the HO-treated (642.98±57.25) and iCORM-2-treated (342.11±131.25) groups were markedly increased as compared with the medium-treated (78.72±74.17) and CORM-2-treated (71.42±53.35) groups (P<0.05), and no significant difference was observed between the medium-treated and CORM-2-treated groups (P>0.05). In conclusion, our study demonstrated that in the in vitro oxidative stress injury model of primary RPTECs, CORM-2 can significantly inhibit the nuclear-cytoplasmic translocation of HMGB1, which is probably associated with the prevention of HMGB1 acetylation.