Do changes in transglutaminase activity alter latent transforming growth factor beta activation in experimental diabetic nephropathy?

Background. Diabetic nephropathy is the leading cause of end-stage kidney failure worldwide. It is characterized by excessive extracellular matrix accumulation. Transforming growth factor beta 1 (TGF-ß1) is a fibrogenic cytokine playing a major role in the healing process and scarring by regulating extracellular matrix turnover, cell proliferation and epithelial mesanchymal transdifferentiation. Newly synthesized TGF-ß is released as a latent, biologically inactive complex. The cross-linking of the large latent TGF-ß to the extracellular matrix by transglutaminase 2 (TG2) is one of the key mechanisms of recruitment and activation of this cytokine. TG2 is an enzyme catalyzing an acyl transfer reaction leading to the formation of a stable e(?-glutamyl)-lysine cross-link between peptides.Methods. To investigate if changes in TG activity can modulate TGF-ß1 activation, we used the mink lung cell bioassay to assess TGF-ß activity in the streptozotocin model of diabetic nephropathy treated with TG inhibitor NTU281 and in TG2 overexpressing opossum kidney (OK) proximal tubular epithelial cells.Results. Application of the site-directed TG inhibitor NTU281 caused a 25% reduction in kidney levels of active TGF-ß1. Specific upregulation of TG2 in OK proximal tubular epithelial cells increased latent TGF-ß recruitment and activation by 20.7% and 19.7%, respectively, in co-cultures with latent TGF-ß binding protein producing fibroblasts.Conclusions. Regulation of TG2 directly influences the level of active TGF-ß1, and thus, TG inhibition may exert a renoprotective effect by targeting not only a direct extracellular matrix deposition but also TGF-ß1 activation and recruitment.

Transglutaminase inhibition reduces fibrosis and preserves function in experimental chronic kidney disease

Progressive tissue fibrosis is involved in debilitating diseases that affect organs including the lungs, liver, heart, skin, and kidneys. Recent evidence suggests that tissue transglutaminase, an enzyme that crosslinks proteins, may be involved in tissue fibrosis by crosslinking and stabilizing the extracellular matrix or by recruiting and activating the large latent transforming growth factor (TGF)-β1 complex. We treated rats that had undergone 5/6-nephrectomy with two different irreversible inhibitors of transglutaminase and found that both prevented a decline in kidney function and reduced the development of glomerulosclerosis and tubulointerstitial fibrosis by up to 77% and 92%, respectively. Treatment reduced the accumulation of collagen I and collagen III, with the primary mechanism of action being direct interference with the crosslinking of extracellular matrix rather than altered regulation of TGFβ1. We conclude that inhibition of transglutaminase offers a potential therapeutic option for chronic kidney disease and other conditions that result from tissue fibrosis. Copyright © 2007 by the American Society of Nephrology.

Involvement of NADPH oxidases in cardiac remodelling and heart failure

Cardiac remodelling occurs in response to stress, such as chronic hypertension or myocardial infarction, and forms the substrate for subsequent development of heart failure. Key pathophysiological features include ventricular hypertrophy, interstitial fibrosis, contractile dysfunction, and chamber dilatation. Although the molecular mechanisms are complex and not fully defined, substantial evidence now implicates increased oxidative stress as being important. The NADPH oxidase ('Nox') enzymes are a particularly important source of reactive oxygen species that are implicated in redox signalling. This article reviews the evidence for an involvement of NADPH oxidases in different aspects of adverse cardiac remodelling. A better understanding of the roles of this complex enzyme family may define novel therapeutic targets for the prevention of heart failure. Copyright © 2007 S. Karger AG.

Tissue transglutaminase and the progression of human renal scarring

ABSTRACT. Experimental renal scarring indicates that tissue transglutaminase (tTg) may be associated with the accumulation of extracellular matrix (ECM), both indirectly via TGF-β1 activation and directly by the formation of ε(γ-glutamyl) lysine dipeptide bonds within the ECM. The latter potentially accelerates deposition and confers the ECM with resistance to proteolytic digestion. Studied were 136 human renal biopsy samples from a range of chronic renal diseases (CRD) to determine changes in tTg and ε(γ-glutamyl) lysine crosslinking. Immunofluorescence for insoluble tTg showed a 14-fold increase in the kidneys of CRD patients (5.3 ± 0.5 versus 76 ± 54 mV/cm2), which was shown to be active by a similar 11-fold increase in the ε(γ-glutamyl) lysine crosslink (1.8 ± 0.2 versus 19.3 ± 14.2 mV/cm2). Correlations were obtained with renal function for tTg and crosslink. In situ hybridization for tTg mRNA showed that tubular epithelial cells were the major source of tTg; however, both mesangial and interstitial cells also contributed to elevated levels in CRD. This mRNA pattern was consistent with immunohistochemistry for soluble tTg. Changes in renal tTg and its product, the ε(γ-glutamyl) lysine crosslink, occur in progressive renal scarring in humans independently of the original etiology and in a similar manner to experimental models. tTg may therefore play a role in the pathogenesis of renal scarring and fibrosis in patients with CRD and can therefore be considered a potential therapeutic target. E-mail: T.Johnson@sheffield.ac.uk

Validação do conteúdo do diagnóstico de enfermagem proteção ineficaz para pacientes submetidos à hemodiálise

Methodological study, in order to validate the content of the nursing diagnosis protection ineffective in patients undergoing hemodialysis. The research took place in two stages, namely: concept analysis and content analysis of the instrument by experts. T he first step was operationalized through an integrative review of the databaes LILACS, CINAHL, PubMed, Scopus and Cochrane, with the key words protection and hemodialysis, in October and November 2013. The sample consisted of 32 articles, which were analyz ed by a c areful reading to identify the sections that correspond ed to the defining attributes , antecedents and consequences of protection in patients undergoing hemodialysis. T he interpretation for the diagnosis of effective protection was made by transpos ing the components of the diagnosis (definition, defining characteristics and related factors) to the denial form . In the second stage, we elaborated an instrument with the components of the nursing diagnostic s studied and proceeded to the analysis conduct ed in April 2014 by 22 specialists in nephrology and in the terminology of the NANDA International, selected by means of th e Lattes Platform . We used the binomial test to assess the proportion of experts who rated each item as appropriate, considering a si gnificance level of 5%. The project was approved by the Ethics Committee of the institution responsible for the research, an opinion on num b er 387 837 and CAAE 18486413.0.0000.5537. The results show that the proposal for the nursing diagnosis of ineffectiv e protection in patients undergoing hemodialysis is: definition - the same as that presented in the NANDA International Taxonomy II, location - domain safety / protection and class injury. Related factors are: Absence of routine vaccines; Non - adherence to care related to vascular access; Non - adherence to infection control measures; Non - adherence to prescribed diet; Non - adherence to drug therapy; Presence of comorbidities; Drug abuse; Immune disorders; Extremes of age; Abnormal blood profiles; Drugs that red uce immunity; and side effects and adverse treatment - related. The defining characteristics are: Presence of invading the bloodstream; Nutritional disorders; Increase in the number of hospitalizations; Uncontrolled dry weight; Infected vascular access; Vasc ular inadequate access; Increased blood pressure; fever; Bleeding disorder; Disability immunity; fatigue; weakness; itching; and maladaptive response to stress. It follows that the identification of the defining attributes, antecedents and consequences inc reased the wealth of vocabulary, allowing the construction of theoretical and empirical definitions for a broader understanding of the concept protection. Furthermore, the study contributed to the enrichment of nursing specific body of knowledge, as well a s in the direction of nursing care for patients undergoing hemodialysis.

Avaliação de qualidade da unidade de diálise no Hospital Universitário Onofre Lopes - HUOL

Over the years there has been a broader definition of the term health. At the same time it was found also an evolution of the concept of health care which in turn has led to changes in the approach to delivery of health services and hence in its management. In this regard, currently the nephrology services have been searching for quality technical and social need. In view of these innovations and the quest for quality, it elaborated the general objective: to develop a quality assessment protocol for dialysis service Onofre Lopes University Hospital. It is an intervention project effected through an action research, which consisted of 4 steps. Initially was identified through a literature search in scientific literature, which quality indicators would apply to a dialysis unit being selected as follows: infection rate in hemodialysis access site, microbiological control of water used for hemodialysis and Index User satisfaction. Through critical reflection on the theme researched in the previous step, it was drawn up three data collection instruments, interview form type, applied between the months of October and November 2015. In addition to the information obtained, also made up of the use of information retrieval technique. The results were organized in graphs and tables and analyzed using qualitative and exploratory technical approach. Then a reflective analysis of the data obtained and the diagnosis of reality studied was traced and confronted with the literature was performed. The data produced in this study revealed that the Dialysis Unit of HUOL is much to be desired, considering that some weaknesses have been identified in its structure. Faced with this finding have been proposed, as a contribution and aiming to guide the development of future actions, suggestions for improvement that should be implemented and monitored to be assured overcoming these difficulties, allowing an appropriate organizational restructuring, and resulting in improved service public offered. It was concluded that for hemodialysis treatment results are achieved and positive, it is necessary to have physical structure and adequate infrastructure, multidisciplinary team specialized, trained and in sufficient quantity, well designed processes for professionals to have standards to be followed decreasing the chance to err, and a risk management system to detect and control situations that endanger patient safety.

Avaliação de qualidade da unidade de diálise no Hospital Universitário Onofre Lopes - HUOL

Over the years there has been a broader definition of the term health. At the same time it was found also an evolution of the concept of health care which in turn has led to changes in the approach to delivery of health services and hence in its management. In this regard, currently the nephrology services have been searching for quality technical and social need. In view of these innovations and the quest for quality, it elaborated the general objective: to develop a quality assessment protocol for dialysis service Onofre Lopes University Hospital. It is an intervention project effected through an action research, which consisted of 4 steps. Initially was identified through a literature search in scientific literature, which quality indicators would apply to a dialysis unit being selected as follows: infection rate in hemodialysis access site, microbiological control of water used for hemodialysis and Index User satisfaction. Through critical reflection on the theme researched in the previous step, it was drawn up three data collection instruments, interview form type, applied between the months of October and November 2015. In addition to the information obtained, also made up of the use of information retrieval technique. The results were organized in graphs and tables and analyzed using qualitative and exploratory technical approach. Then a reflective analysis of the data obtained and the diagnosis of reality studied was traced and confronted with the literature was performed. The data produced in this study revealed that the Dialysis Unit of HUOL is much to be desired, considering that some weaknesses have been identified in its structure. Faced with this finding have been proposed, as a contribution and aiming to guide the development of future actions, suggestions for improvement that should be implemented and monitored to be assured overcoming these difficulties, allowing an appropriate organizational restructuring, and resulting in improved service public offered. It was concluded that for hemodialysis treatment results are achieved and positive, it is necessary to have physical structure and adequate infrastructure, multidisciplinary team specialized, trained and in sufficient quantity, well designed processes for professionals to have standards to be followed decreasing the chance to err, and a risk management system to detect and control situations that endanger patient safety.

Looking to the future : Predicting renal replacement outcomes in a large community cohort with chronic kidney disease

Peer reviewed

Looking to the future : Predicting renal replacement outcomes in a large community cohort with chronic kidney disease

Peer reviewed

Looking to the future : Predicting renal replacement outcomes in a large community cohort with chronic kidney disease

Peer reviewed

The Genetic Landscape of Renal Complications in Type 1 Diabetes

Diabetes is the leading cause of end stage renal disease. Despite evidence for a substantial heritability of diabetic kidney disease, efforts to identify genetic susceptibility variants have had limited success. We extended previous efforts in three dimensions, examining a more comprehensive set of genetic variants in larger numbers of subjects with type 1 diabetes characterized for a wider range of cross-sectional diabetic kidney disease phenotypes. In 2,843 subjects, we estimated that the heritability of diabetic kidney disease was 35% ( p=6x10-3 ). Genome-wide association analysis and replication in 12,540 individuals identified no single variants reaching stringent levels of significance and, despite excellent power, provided little independent confirmation of previously published associated variants. Whole exome sequencing in 997 subjects failed to identify any large-effect coding alleles of lower frequency influencing the risk of diabetic kidney disease. However, sets of alleles increasing body mass index ( p=2.2×10-5) and the risk of type 2 diabetes (p=6.1x10-4 ) were associated with the risk of diabetic kidney disease. We also found genome-wide genetic correlation between diabetic kidney disease and failure at smoking cessation ( p=1.1×10-4 ). Pathway analysis implicated ascorbate and aldarate metabolism ( p=9×10-6), and pentose and glucuronate interconversions ( p=3×10-6) in pathogenesis of diabetic kidney disease. These data provide further evidence for the role of genetic factors influencing diabetic kidney disease in those with type 1 diabetes and highlight some key pathways that may be responsible. Altogether these results reveal important biology behind the major cause of kidney disease.  

Immobilized kidney 28 KDa endostatin-related (KES28KDa) fragment promotes endothelial cell survival

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tubular Urinary Enzymes in Acute Post-infectious Glomerulonephritis

Tubular function of 17 pediatric patients with a mild form of acute post-infectious glomerulonephritis was prospectively evaluated by assessment of the urinary activity of proximal and distal tubule enzymes. Neutral-like endopeptidase (NEP-like) and angiotensin-converting enzyme (ACE) were the proximal tubule enzymes assessed, while prolyl-endopeptidase (PE) and serine-endopeptidase H1 and H2 were the distal tubule enzymes analyzed. Urine was collected at diagnosis (T0) and after 2 (T2) and 6 (T6) months of follow-up. NEP-like enzyme activity (nmol/mg creatinine; median±quartile range) was increased at diagnosis, and this remained stable during the first 6 months (T0 18.30±83.26, T2 17.32±49.56, T6 23.38±107.18). Urinary activity of the other enzymes was as follows: ACE (mU/ml per mg creatinine) T0 0.08±0.16, T2 0.06±0.10, T6 0.18±0.29; PE (nmol/mg creatinine) T0 6.70±84.87, T2 9.55±69.00, T6 13.67±28.70; serine-endopeptidase H1 (nmol/mg creatinine) T0 7.86±26.95, T2 17.17±59.37, T6 18.19± 79.14; and serine-thiol-endopeptidase H2 (nmol/mg creatinine) T0 3.06±21.97, T2 12.06±32.42, T6 16.22± 44.06. Thirty other healthy children matched for age and gender were considered as a control group. This group was assessed once and the results were: NEP-like activity 6.05±10.54, ACE 0.11±0.22, PE 7.10±13.36, H1 5.00±17.30, and H2 6.00±20.16. In conclusion, we observed that NEP-like and H1 enzymes exhibited significant increased urinary activity 6 months after the diagnosis. This increase occurred in spite of the disappearance of clinical symptoms, which occurred 2 months after the diagnosis. We believe that the increase in urinary enzymatic activity could be a manifestation of a silent tubular dysfunction following an episode of acute post-infectious glomerulonephritis.

Postnatal Evaluation and Outcome of Prenatal Hydronephrosis

Background: Prenatal hydronephrosis (PNH) is dilation in urinary collecting system and is the most frequent neonatal urinary tract abnormality with an incidence of 1% to 5% of all pregnancies. PNH is defined as anteroposterior diameter (APD) of renal pelvis ≥ 4 mm at gestational age (GA) of < 33 weeks and APD ≥ 7 mm at GA of ≥ 33 weeks to 2 months after birth. All patients need to be evaluated after birth by postnatal renal ultrasonography (US). In the vast majority of cases, watchful waiting is the only thing to do; others need medical or surgical therapy. Objectives: There is a direct relationship between APD of renal pelvis and outcome of PNH. Therefore we were to find the best cutoff point APD of renal pelvis which leads to surgical outcome. Patients and Methods: In this retrospective cohort study we followed 200 patients 1 to 60 days old with diagnosis of PNH based on before or after birth ultrasonography; as a prenatal or postnatal detected, respectively. These patients were referred to the nephrology clinic in Zahedan Iran during 2011 to 2013. The first step of investigation was a postnatal renal US, by the same expert radiologist and classifying the patients into 3 groups; normal, mild/moderate and severe. The second step was to perform voiding cystourethrogram (VCUG) for mild/moderate to severe cases at 4 - 6 weeks of life. Tc-diethylene triamine-pentaacetic acid (DTPA) was the last step and for those with normal VCUG who did not show improvement in follow-up examination, US to evaluate obstruction and renal function. Finally all patients with mild/moderate to severe PNH received conservative therapy and surgery was preserved only for progressive cases, obstruction or renal function ≤35%. All patients’ data and radiologic information was recorded in separate data forms, and then analyzed by SPSS (version 22). Results: 200 screened PNH patients with male to female ratio 3.5:1 underwent first postnatal control US, of whom 65% had normal, 18% mild/moderate and 17% severe hydronephrosis. 167 patients had VCUG of whom 20.82% with VUR. 112 patients performed DTPA with following results: 50 patients had obstruction and 62 patients showed no obstructive finding. Finally 54% of 200 patients recovered by conservative therapy, 12.5% by surgery and remaining improved without any surgical intervention. Conclusions: The best cutoff point of anteroposterior renal pelvis diameter that led to surgery was 15 mm, with sensitivity 88% and specificity 74%.