Thesis (MScMedSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The purpose of this study was to investigate the association of the selected MYH9 single nucleotide polymorphisms (SNPs) with chronic kidney disease (CKD) and its related co-morbidities in the South African mixed ancestry population residing in Bellville South, Cape Town. In 2008, two landmark studies identified SNPs in the MYH9 gene which explained most of the increased risk for non-diabetic CKD in African Americans. These polymorphisms were later found to be weakly associated with diabetic nephropathy. Three SNPs that exhibited independent evidence for association with CKD were selected (rs5756152, rs4821480 and rs12107). These were genotyped using a Taqman genotyping assay on a BioRad MiniOpticon and confirmed by sequencing in 724 subjects from Bellville South, Cape Town, South Africa. Prevalent CKD was defined based on the estimated glomerular filtration rate calculated using the modification of diet in renal disease (MDRD) formula. Chronic kidney disease was present in 214 subjects (29.6%), 96.3% were stage 3 and only 8 subjects were stage 4. In additive allelic models, adjusted for age and gender, rs5756152 demonstrated an association with kidney function whereby each G allele of rs5756152 increased eGFR by 3.67 ml/min/1.73, reduced serum creatinine by 4.5% and increased fasting plasma glucose by 0.51 mmol/L. When an interaction model was used, the effect of rs5756152 on serum creatinine, eGFR and blood glucose levels was retained, and enhanced, but only in diabetic subjects. In addition, rs4821480 T allele increased eGFR while rs12107 A allele decreased glucose levels in diabetic subjects. In contrast to reports that MYH9 SNPs are strongly associated with non-diabetic end stage renal disease, our study demonstrated that rs5756152 and rs4821480 are associated with early kidney function derangements in type 2 diabetes whilst rs12107 is associated with glucose metabolism. Our findings, along with previous reports, suggest that the MYH9 gene may have a broader genetic risk effect on different types of kidney diseases than previously thought. / AFRIKAANSE OPSOMMING: Hierdie studie het ondersoek ingestel na die verband tussen drie gekose MYH9-enkelnukleotied-polimorfismes (SNP’s) en chroniese niersiekte (hierna ‘niersiekte’), wat verwante ko-morbiditeite insluit, onder ’n Suid-Afrikaanse populasie van gemengde afkoms in Bellville-Suid, Kaapstad. Twee rigpuntstudies het in 2008 op SNP’s in die MYH9-geen afgekom wat verklaar het waarom Afro-Amerikaners ’n hoër risiko vir niediabetiese niersiekte toon. Later is bevind dat hierdie polimorfismes ook ’n swak verband met diabetiese nefropatie het. Drie SNP’s wat elk onafhanklik bewys gelewer het van ’n verband met niersiekte is vervolgens gekies (rs5756152, rs4821480 en rs12107). Die SNP’s is daarná met behulp van die Taqman-toets op ’n BioRad MiniOpticon aan genotipering onderwerp, en is toe deur middel van reeksbepaling by 724 proefpersone van Bellville-Suid, Kaapstad, Suid-Afrika, bevestig. Die voorkoms van niersiekte is bepaal op grond van die geraamde glomerulêre filtrasietempo (eGFR), wat aan die hand van die ‘niersiekte-dieetveranderings’- (MDRD-)formule bereken is. Daar is bevind dat 214 proefpersone (29,6%) aan chroniese niersiekte ly – 96,3% was in fase 3 en slegs agt proefpersone in fase 4. In toegevoegde alleliese modelle wat vir ouderdom en geslag aangepas is, het rs5756152 ’n verband met nierfunksie getoon: Elke G-allel van rs5756152 het eGFR met 3,67 ml/min/1,73 verhoog, serumkreatinien met 4,5% verlaag en vastende plasmaglukose met 0,51 mmol/L verhoog. Toe ’n interaksiemodel gebruik is, is die effek van rs5756152 op serumkreatinien, eGFR en bloedglukosevlakke behou en versterk, hoewel slegs by diabetiese proefpersone. Daarbenewens het die T-allel van rs4821480 eGFR verhoog, terwyl die A-allel van rs12107 ook glukosevlakke by diabetiese proefpersone verlaag het. In teenstelling met bewerings dat MYH9-SNP’s ’n sterk verband met niediabetiese eindstadiumniersiekte toon, het hierdie studie bewys dat rs5756152 en rs4821480 met vroeë nierfunksieversteurings by tipe 2-diabetes verband hou, terwyl rs12107 weer met glukosemetabolisme verbind word. Tesame met vorige studies, doen hierdie navorsingsbevindinge dus aan die hand dat die MYH9-geen dalk ’n groter genetiese risiko-effek op verskillende tipes niersiekte het as wat voorheen vermoed is. / Cape Peninsula University of Technology Research Fund / University of Stellenbosch Merit Bursary

The progressively increasing prevalence of the Metabolic Syndrome (MetS) has emerged as a major global health concern since the MetS is associated with an increased risk for cardiovascular morbidity and mortality. Central obesity represents a key feature of the MetS and is strongly related to all MetS comorbidities. Dysregulation of adipose tissue-derived proteins, so called adipokines, has been implied to partially contribute to these effects. Recently, fibroblast growth factor-21 (FGF-21) has been introduced as a novel insulin sensitizing and weight reducing adipokine with potential therapeutic properties. However, data on FGF-21 elimination are rather limited. Therefore, FGF-21 regulation in relation to renal function has been investigated in a patient population with chronic kidney disease (CKD, study population 1), as well as one with acute kidney impairment (study population 2). In study population 1 (n = 499), patients were distributed into five CKD subgroups according to estimated glomerular filtration rate (eGFR). Median FGF-21 serum concentrations progressively increased from CKD stage 1 to stage 5 and highest values of FGF-21 were detected in stage 5 (1: 86.4 ng/l; 2: 206.4 ng/l; 3: 289.8 ng/l; 4: 591.3 ng/l; 5: 1918.1 ng/l). Furthermore, eGFR remained the strongest predictor for FGF-21 levels in multivariate analysis. For study population 2 (n = 32), blood samples were obtained before elective unilateral partial or total nephrectomy, as well as within 30 hours after surgery. In this population FGF-21 levels significantly increased after surgery (325.0 ng/l) as compared to before surgery (255.5 ng/l). Furthermore, relative changes of FGF-21 were independently and positively predicted by relative changes of creatinine in this cohort. These results are in accordance with the hypothesis that FGF-21 is eliminated by the kidneys and that the extent of kidney dysfunction substantially contributes to serum FGF-21 levels. However, additional animal experiments and prospective clinical studies are needed to further elucidate the role of the kidneys in FGF-21 physiology.

Patients with chronic kidney disease are at higher risk of developing cardiovascular disease. The complex, interaction between the kidney and the cardiovascular system is incompletely understood, particularly at the early stages of the cardiovascular continuum. The overall aim of this thesis was to clarify novel aspects of the interplay between the kidney and the cardiovascular system at different stages of the cardiovascular continuum; from risk factors such as insulin resistance, inflammation and oxidative stress, via sub-clinical cardiovascular damage such as endothelial dysfunction and left ventricular dysfunction, to overt cardiovascular death. This thesis is based on two community-based cohorts of elderly, Uppsala Longitudinal Study of Adult Men (ULSAM) and Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). The first study, show that higher insulin sensitivity, measured with euglycemic-hyperinsulinemic clamp technique was associated to improve estimated glomerular filtration rate (eGFR) in participants with normal fasting plasma glucose, normal glucose tolerance and normal eGFR. In longitudinal analyses, higher insulin sensitivity at baseline was associated with lower risk of impaired renal function during follow-up. In the second study, eGFR was inversely associated with different inflammatory markers (C-reactive protein, interleukin-6, serum amyloid A) and positively associated with a marker of oxidative stress (urinary F2-isoprostanes). In line with this, the urinary albumin/creatinine ratio was positively associated with these inflammatory markers, and negatively associated with oxidative stress. In study three, higher eGFR was associated with better endothelial function as assessed by the invasive forearm model. Further, in study four, higher eGFR was significantly associated with higher left ventricular systolic function (ejection fraction). The 5th study of the thesis shows that higher urinary albumin excretion rate (UAER) and lower eGFR was independently associated with an increased risk for cardiovascular mortality. Analyses of global model fit, discrimination, calibration, and reclassification suggest that UAER and eGFR add relevant prognostic information beyond established cardiovascular risk factors in participants without prevalent cardiovascular disease. Conclusion: this thesis show that the interaction between the kidney and the cardiovascular system plays an important role in the development of cardiovascular disease and that this interplay begins at an early asymptomatic stage of the disease process.

Cardiovascular disease (CVD) and erectile dysfunction (ED) have common etiologies, such as increased adiposity and chronic diseases. Incident ED is known to be a sentinel of CVD, providing a unique opportunity for early lifestyle interventions to attenuate the progression of disease. The internal pudendal artery (IPA) plays an important role in controlling resistance to penile blood flow and thereby erections. Although morphological and functional disturbances in the IPA have been associated with ED, few studies have characterized changes in the IPA as it relates to increased adiposity and chronic diseases (e.g., chronic kidney disease [CKD]). Finally, although both vascular calcification and ED have been shown to be prevalent in patients with CKD, there has yet to be an assessment of associated mechanisms. The effect of lifestyle modifications on erectile function was evaluated in both experimental and clinical settings. Specifically, the studies assessed the effect of caloric restriction (CR) in rats and of chronic exercise in sedentary, overweight or obese male and female subjects. In rats, structural and functional changes of the IPA and erectile responses were characterized in relation to increasing adiposity and to CKD. Experimentally, the susceptibility of various vascular beds to calcification in CKD was determined. Clinically, erectile and female sexual function was assessed in patients with Stage 3 to 5 CKD, who had no history of CVD. In rats, CR blunted the accumulation of abdominal adiposity, and attenuated progression of both endothelial dysfunction and ED, independently of morphological changes in the IPA. Rats with CKD had an increased frequency of ED, greater endothelial dysfunction, and altered vascular morphology, yet vascular calcification per se did not account for ED. In the clinical study, sedentary and overweight or obese males with ED, but not females, had a significantly higher body mass index (BMI) and waist circumference. Chronic exercise significantly improved ED and female sexual dysfunction (FSD). Clinically, CKD was associated with ED and FSD as well as increased coronary artery calcification and endothelial dysfunction. These findings support the concept that early detection of cardiovascular abnormalities, using incident ED as a sentinel, should facilitate early interventions in otherwise asymptomatic populations. / Thesis (Ph.D, Pharmacology & Toxicology) -- Queen's University, 2013-09-30 22:33:20.436

A growing number of factors, including costs, technological advancements, ageing populations, and medical errors, are leading industrialized countries to invest in research on alternative solutions to improve their health-care systems and increase patients’ quality of life. Personal health systems (PHS) examplify the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centered healthcare delivery model toward a preventive and person-centered approach. PHS offer the means to monitor a patient’s health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive biodata acquisition, allowing remote monitoring of treatment and access to the patient’s status. Electrical bioimpedance (EBI) technology is non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. When combined with state-of-the-art advances in sensors and textiles, EBI technologies are fostering the implementation of wearable bioimpedance monitors that use functional garments for personalized healthcare applications. This research work is focused on the development of wearable EBI-based monitoring systems for ubiquitous health monitoring applications. The monitoring systems are built upon portable monitoring instrumentation and custom-made textile electrode garments. Portable EBI-based monitors have been developed using the latest material technology and advances in system-on-chip technology. For instance, a portable EBI spectrometer has been validated against a commercial spectrometer for total body composition assessment using functional textile electrode garments. The development of wearable EBI-based monitoring units using functional garments and dry textile electrodes for body composition assessment and respiratory monitoring has been shown to be a feasible approach. The availability of these measurement systems indicates progress toward the real implementation of personalized healthcare systems. / <p>QC 20170517</p>

L'administration chronique de rHuEPO peut engendrer de graves effets secondaires. Une augmentation de l’hématocrite provoquée par la rHuEPO, en augmentant l'érythrocytose, la viscosité sanguine et les forces de cisaillement à la surface vasculaire, peut être responsable d'hypertension artérielle (HTA) et de thromboses artérielles. La présence d'une fonction endothéliale normale et de monoxyde d'azote (NO) peut contrer les effets délétères thrombogène et hypertenseur de l'EPO. Sur ces bases, nous avons étudié les effets cardiovasculaires d'une administration chronique de rHuEPO dans différentes situations : dans le cadre du dopage, chezdes rats "sportifs" présentant une dysfonction endothéliale NO-dépendante induite par l'administration chronique de L-NAME et dans le cadre d'un traitement chez des rats urémiques développant une dysfonction endothéliale NO-dépendante résultante d'une néphrectomie de 5/6de la masse rénale. Chez nos rats entrainés, dopés et traités au L-NAME, nous avons observé une altération de la performance physique avec une mortalité importante (51%). Une HTA sévères'est développée chez ces rats, avec des valeurs de pression artérielle (> 220 mmHg) bien plusélevées que celles des rats recevant le L-NAME seul, associée à une altération de la vasorelaxation NO-dépendante aortique (< 60%). Les rats insuffisants rénaux (IRC) ont eux aussi montré une augmentation de la pression artérielle et une dysfonction endothéliale en réponse àl'acétylcholine au niveau de l'aorte et en réponse à une élévation du flux au niveau de l'artère mésentérique perfusée. Ces différents paramètres ont été améliorés par l'exercice. Les coupes de rein colorées au rouge Sirius ont montré une fibrose accentuée chez les rats CKD. La fibrose, la créatinémie et l'albuminurie ont été diminuées par l'exercice seul mais ont été aggravées chez les rats du groupe CKD+EPO+Ex. L'activité NADPH oxydase et l'expression des Nox4, p67phox etMAPK erk1/2 ont été augmentées chez les les rats CKD. L'exercice ou la rHuEPO ont prévenuces augmentations. Cependant, l'activité de la NAD(P)H oxydase et l’expression des MAPKerk1/2 sont restées élevées dans le rein des rats CKD+EPO+Ex. Nos données suggèrent que l'exercice seul a un effet protecteur contre les dysfonctions vasculaire et rénale et la fibrose rénale. Ces effets protecteurs sont associés à une inhibition de l'activité de la NADPH oxydase et des voies de signalisation MAPK erk1/2. Par contre, l'exercice combiné avec le traitement rHuEPO, a des effets délétères sur la structure et la fonction rénale des rats CKD. Ces effets nocifs semblent liés à la stimulation de la NADPH oxydase et des voies de signalisation MAPKerk1/2. Malgré les effets protecteurs cardiovasculaire et rénal de l'entraînement physique, ces résultats mettent en évidence que la fonction rénale peut être potentiellement endommagée ainsique la structure du rein en combinant l'exercice avec le traitement rHuEPO dans l'insuffisance rénale. En conclusion, nous pouvons dire que la rHuEPO affecte gravement la fonction cardiovasculaire du rat entraîné présentant une dysfonction endothéliale. Ce risque étant fatal,beaucoup de sportifs, voulant augmenter leur performance, mettent leur vie en danger. Par ailleurs, ayant remarqué les effets délétères au niveau rénal, en associant exercice et traitement rHuEPO dans des conditions expérimentales sur un modèle d'insuffisance rénale, nous suggérons une investigation clinique afin de vérifier la transposition de nos résultats aux patients insuffisants rénaux. / The chronic administration of rHuEPO can engender side effects. An increase of the hematocritinduced by rHuEPO, by increasing the erythrocytosis, the blood viscosity and the shear stress onvascular surface, can be responsible of arterial high blood pressure and arterial thrombosis. Thepresence of a normal endothelial function and nitric oxide (NO) can counter the noxious effectsof rHuEPO. On these bases, we studied the cardiovascular effects of a chronic administration ofrHuEPO in various frames: within doping field, to trained rats with L-NAME-induced NOdependentendothelial dysfunction and within the framework of a treatment, to chronic kidneydisease (CKD) rats developing endothelial dysfunction caused by the "5/6 nephrectomy". In ourdoped rats, we observed an important mortality (51%). A severe arterial high blood pressuredeveloped in these rats (> 220 mmHg) associated with an impairment of the NO-dependentvasorelaxation (< 60 %). CKD rats also showed an increase in blood pressure and an endothelialdysfunction, in response to acetylcholine in the aorta and in response to a rise in flow in perfusedmesenteric artery. These parameters were improved by exercise. Kidney sections stained withSirius red showed marked fibrosis in CKD rats. Fibrosis, creatinine and albumin were decreasedby exercise alone but were increased in rats from the CKD + EPO + Ex group. NAD(P)H oxidaseactivity and the expression of Nox4, p67phox, and MAPK erk1/2 were increased in CKDrats. Exercise or rHuEPO prevented these increases. However, the NAD(P)H oxidase activityand the expression of MAPK erk1/2 remained high in the kidney of rats from the CKD+EPO+Exgroup. Our data suggest that exercise alone has a protective effect against vascular and renaldysfunction and renal fibrosis. These protective effects are linked to the downregulation of theNADPH oxidase activity and MAPK erk1/2 signaling pathways. However, exercise combinedwith rHuEPO treatment has deleterious effects on kidney structure and function in CKDrats. These adverse effects appear to be related to the stimulation of NADPH oxidase and MAPKerk1/2 signaling pathways. Despite the cardiovascular and renal protective effects of physicaltraining, these results highlight the potentially damaging renal function and structure bycombining exercise with rHuEPO therapy in renal failure. In conclusion, we can say that therHuEPO affects seriously cardiovascular function in trained rat with endothelial dysfunction. Thisrisk being fatal, many sportsmen, looking to increase their performance, put their life in danger.Moreover, having noticed the deleterious effects in the kidney by combining exercise andrHuEPO therapy under experimental conditions on a model of renal failure, we suggest a clinicalinvestigation to verify the transposition of our results to patients with renal failure

L'insuffisance rénale chronique (IRC) se caractérise par la diminution progressive et irréversible des fonctions renales. Elle s'accompagne d'une accumulation d'un ensemble de toxines responsable du syndrome urémique. Le syndrome urémique touche tous les organes, et de façon préoccupante le système cardiovasculaire. Il est associé à une dysfonction endothéliale, à la production d'un stress oxydant et d'une inflammation. L'objectif de cette thèse était d'identifier les mécanismes moléculaires responsables des complications du syndrome urémique. La première partie a tenté d'identifier des épissages alternatifs associés à l'IRC. Deux épissages alternatifs ont été identifiés. Cependant, le petit nombre d'épissages alternatifs trouvé au vue du nombre de gènes étudiés, nous permet de conclure que si l'IRC peut être responsable de l'apparition d'épissages alternatifs, ce phénomène n'est pas déterminant dans la régulation de l'expression des gènes responsable des complications de l'IRC. Dans la deuxième partie, nous avons montré par une étude clinique que le taux d'une toxine urémique, l'acide indole acétique (IAA), était associé à la mortalité et à la survenue d'événements cardio-vasculaires. In vitro, l'IAA induit un stress oxydant et un signal inflammatoire par l'induction de la cyclooxygénase 2 (COX-2). Une voie inflammatoire non génomique impliquant aryl hydrocarbon receptor (AhR), p38 MAPK et NF-κB est responsable de l'induction de la COX-2 endothéliale par l'IAA. Nos travaux ont identifié de nouvelles cibles thérapeutiques dont la modulation pourrait avoir un impact sur la mortalité cardiovasculaire des patients présentant une maladie rénale chronique. / Chronic kidney disease (CKD) is characterized by an irreversible decrease in kidney functions. Accumulation of uremic toxins is implicated in the uremic syndrome. Uremic syndrome affects all organs and particularly the cardiovascular system. The aim of this thesis was to identify and understand the molecular mechanisms implicated in the uremic syndrome.The first part attempted to ascertain the existence of alternative splice events associated with CKD. Two alternative splicing were identified. The small number of alternative splice events highlighted allows us to conclude that this phenomenon does not seem to be a key event in the modulation of gene expression during CKD.In the second part of this work, we demonstrated that the plasmatic concentration of an uremic toxin, Indole-3-acetic acid (IAA), is associated with all-cause mortality and major cardiovascular events. In vitro, we demonstrated that IAA induced endothelial cyclooxygenase-2 expression and endothelial oxidative stress production. IAA activated an endothelial Aryl hydrocarbon receptor/P38MAPK/NF-κB pathway. The activation of this inflammatory AHR dependant pathway could play a critical role in the increase of cardiovascular morbidity and mortality observed during CKD.Our work provides new therapeutic targets. The modulation of their activation could reduce cardiovascular mortality in patients with chronic kidney disease.

La maladie rénale chronique (MRC) induit des anomalies du métabolisme phosphocalcique, avec des conséquences à la fois osseuses, vasculaires et biologiques. La prise en charge optimale de ces désordres représente un challenge quotidien pour le néphrologue pédiatre, à la fois sur le court terme (équilibre biologique) et sur le long terme (prévention des fractures, optimisation de la croissance et limitation de l’apparition des calcifications vasculaires). Peu d’outils sont actuellement disponibles pour évaluer ces atteintes, et de nouveaux outils prometteurs, à la fois biologiques (FGF23) et radiologiques (HR-pQCT) apparaissent. Néanmoins, les données pédiatriques sur ces outils restent rares. Cette thèse de doctorat a permis d’évaluer ces nouveaux moyens chez ces enfants MRC, notamment en évaluant l’HR-pQCT dans cette population, et en déterminant des valeurs de référence du FGF23 en fonction de l’âge, du sexe et de la fonction rénale. Nous avons pu aussi montrer que les concentrations circulantes de FGF23 ne sont pas dépendantes du sexe dans une population pédiatrique, mais qu’elles augmentent avec l’âge et l’indice de masse corporelle, mais aussi en cas d’antécédent de transplantation d’organe solide ou de traitement par corticostéroïdes. D’un point de vue plus fondamental, nous avons pu montrer que dans des monocytes issus de donneurs sains, une exposition au FGF23 induit une diminution de l’expression des 2 enzymes principales impliquées dans le métabolisme de la vitamine D (1α hydroxylase et 24 hydroxylase), en induisant également une diminution du peptide antimicrobien cathélicidine. Ces résultats permettent donc de décrire un nouveau rôle pour le FGF23 dans la régulation de l’immunité innée / Chronic kidney disease can induce mineral and bone disorders (CKD-MBD), with deleterious consequences for bone and vessels. The management of such abnormalities can be challenging, from the daily biological balance between calcium, phosphorus and PTH levels, to the long-term prevention of morbidities such as fractures, growth impairment and vascular calcifications. Some tools can help to accurately assess CKD-MBD, e.g., new bone imaging techniques (HR-pQCT) and FGF23, but they are rarely used in pediatric populations. In addition to evaluating HR-pQCT in CKD children and healthy controls, this PhD thesis allowed us to determine reference values for circulating FGF23 levels depending on age, gender and renal function; we also showed that FGF23 levels increased not only with age and BMI, but also in cases of solid organ transplant or corticosteroids therapy. We have also showed in vitro that FGF23 could inhibit the two key enzymes of vitamin D metabolism (1α hydroxylase et 24 hydroxylase) in monocytes issued from healthy donors, with in turn a decreased synthesis of the antimicrobial cathelicidin. These later results highlight a new role for FGF23 in innate immunity, and may bring new insights in the understanding of FGF23 deregulation during CKD

A diálise peritoneal constitui uma importante opção terapêutica para o paciente com doença renal crônica (DRC) em estágio 5. Entretanto, a médio-longo prazo, alterações morfofuncionais relacionadas a vários fatores, como bioincompatibilidade das soluções de diálise e infecções peritoneais, entre outros, estabelecem um processo inflamatório e fibrótico na membrana peritoneal, levando à perda da eficiência deste método dialítico. O estado urêmico destes pacientes é um agravante, pois intensifica o processo inflamatório da membrana peritoneal. Estratégias terapêuticas que desacelerem o processo de fibrose da membrana peritoneal dos pacientes com DRC em diálise são de extrema importância. Neste contexto, o presente estudo teve como objetivo estabelecer um modelo de peritonite fibrosante associado à DRC com uremia, que mimetiza a situação clínica, e analisar, neste modelo, o efeito de duas moléculas antifibróticas, o tamoxifeno (TAM) e a BMP-7 (bonemorphogenic protein-7). A DRC com uremia foi induzida em ratos Wistar através da administração de dieta rica em adenina, por um período de 30 dias. Nos últimos 15 dias, com o estado de uremia já estabelecido, os animais receberam injeções intraperitoneais de gluconato de clorexidina para a indução da fibrose peritoneal (FP). Os tratamentos com tamoxifeno (10mg/Kg/dia, por gavagem) e BMP-7 (30ug/Kg, injeções intraperitoneais a cada 3 dias) foram iniciados junto com a indução da fibrose peritoneal. Foram formados 6 grupos experimentais: CONTROLE, animais normais; DRC, animais com doença renal crônica; FP, animais com fibrose peritoneal; DRC/FP, animais com DRC e FP mimetizando a situação clínica; DRC/FP+TAM, animais com DRC e FP tratados com tamoxifeno; e DRC/FP+BMP7, animais com DRC e FP tratados com BMP-7. Durante os 30 dias de seguimento do estudo foram verificados o peso, a pressão arterial, ureia e creatinina séricas dos animais. Ao término deste período os animais foram sacrificados e o peritônio foi removido e submetido às análises: a) histológica, para avaliar o grau de espessamento (Tricrômio de Masson); b) imunohistoquímica, para localizar e quantificar a presença de células inflamatórias (macrófagos, linfócitos T), miofibroblastos (?-actina) e a atividade de proliferação celular (PCNA); c) análise de citocinas pró-inflamatórias (TNF-alfa, IL-1beta e IL-6) no tecido peritoneal tanto em nível de RNAm, através de PCR em tempo real, como também em nível proteico, através de multiplex; d) PCR em tempo real para determinar a expressão dos componentes da matriz extracelular (colágeno III e fibronectina) e de fatores fibrogênicos (TGF-beta1 e FSP-1). Além disso, com o objetivo de estudar a possível via de sinalização associada à fibrose peritoneal, foi analisada a expressão de SMAD 3 e SMAD 7 no peritônio através de PCR em tempo real e imunohistoquímica para SMAD 3 fosforilada. Por fim, a função peritoneal foi analisada através do teste de ultrafiltração e massa transferida de glicose (MTG). Os dados da evolução ponderal mostraram que, enquanto os animais dos grupos Controle e FP tiveram um ganho de peso significativo em relação ao primeiro dia do protocolo (28% e 18%, respectivamente), os animais dos demais grupos perderam peso significativamente, em média, 26% em relação ao primeiro dia. Todos os animais que receberam dieta rica em adenina e que, portanto, desenvolveram DRC, apresentaram hipertensão arterial, detectada nos dias 15 e 30 do estudo (média de 173mmHg no dia 15 e 172mmHg no dia 30). Confirmando o estabelecimento de DRC com uremia, os animais que receberam dieta rica em adenina apresentaram níveis séricos significativamente elevados de uréia (em média 170 mg/dL no dia 15 e 286 mg/dL no dia 30) e creatinina (média de 0,97 mg/dL no dia 15 e 1,82 mg/dL no dia 30). Os tratamentos com TAM e BMP-7 não influenciaram significativamente nestes parâmetros. A análise da membrana peritoneal dos animais dos grupos experimentais FP e DRC/FP revelou um espessamento significativo da membrana peritoneal (130 ± 33um e 132 ± 26?m, respectivamente vs 36 ± 2um e 27 ±6 um nos grupos CONTROLE e DRC; p < 0,001) bem como a presença de células inflamatórias. Os tratamentos com TAM e BMP7 foram eficazes em proteger a membrana peritoneal contra o espessamento (42 ± 2?m e 53 ± 7?m, respectivamente; p < 0,001 vs DRC/FP) e contra o infiltrado inflamatório. Além disso, no que se refere aos miofibroblastos, células efetoras da fibrogênese detectadas pela marcação de ?-actina, foi encontrado uma marcação significativa de alfa-actina no peritônio dos grupos FP e DRC/FP (p < 0,01 vs CONTROLE), sendo que os tratamentos com TAM e BMP7 protegeram o peritônio da proliferação maciça de miofibroblastos, confirmada pela expressão de PCNA de forma significativa. Com relação à detecção de citocinas pró-inflamatórias, a análise por PCR em tempo real nos animais do grupo DRC mostrou um aumento significativo da expressão no peritônio de TNF-alfa e IL-1beta comparado ao grupo CONTROLE. A expressão dessas citocinas também se mostrou aumentada no peritônio dos animais dos grupos e DRC/FP. Os tratamentos com TAM e BMP7 reduziram a expressão de TNF-alfa e IL-1beta de forma significativa em relação ao grupo DRC/PF (p < 0,01). O reflexo destes resultados pode ser observado com o ensaio por multiplex em que a presença dessas citocinas em sua forma proteica foi encontrada em quantidades significativas no peritônio dos animais com FP e uremia associada à FP em relação ao grupo CONTROLE. Os tratamentos com TAM e BMP7 reduziram a presença dessas citocinas de forma significativa (p < 0,01 vs DRC/FP). Como esperado, a presença de RNAm de componentes da matriz extracelular foi significativamente maior nos grupos FP e DRC/FP, comparados ao grupo CONTROLE. De fato, a expressão de colágeno III foi maior nos grupos FP e DRC/FP (3,4 ± 1 e 10,3 ± 2,4 UI, respectivamente; p < 0,01 vs CONTROLE), bem como de fibronectina nos grupos (6,5 ± 0,8 e 29,2 ± 1 UI, respectivamente; p < 0,01 vs CONTROLE). Os animais tratados com TAM e BMP7 apresentaram uma diminuição significativa tanto da expressão de colágeno III (1,5±0,9 e 0,2±0,1 UI, respectivamente; p < 0,01 vs DRC/FP), como da expressão de fibronectina (6,6±1,2 e 9,7±0,5 UI, respectivamente; p < 0,01 vs DRC/FP), confirmando um efeito anti-fibrótico dessas drogas. Ainda, enquanto nos grupos FP e DRC/FP a expressão de TGF-? foi significativamente maior em relação ao grupo CONTROLE (13,2±0,9 e 30,3±0,1 UI, respectivamente; p < 0,01), TAM e BMP7 diminuíram a expressão de TGF-beta (17,7±0,2 e 16,2±0,1 UI, respectivamente; p < 0,01 vs DRC/FP). Padrão similar foi encontrado com a expressão do RNAm para FSP-1 em que houve um aumento significativo da expressão desse gene nos grupos FP e DRC/FP, com significativo bloqueio nos animais tratados com TAM e BMP7 (p < 0,01 vs DRC/FP). Com relação à análise das vias de sinalização possivelmente envolvidas no processo, a expressão de SMAD 3 foi significativamente maior nos grupos FP e DRC/FP (3,7±0,3 e 4,6±0,3 UI, respectivamente) em relação aos grupos CONTROLE e DRC (1±0,2 e 1,3±0,6 UI, respectivamente; p < 0,01). Os tratamentos com TAM e BMP7 diminuíram a expressão da SMAD 3 no peritônio (1,1±0,6 e 1,1±0,7 UI, respectivamente; p < 0,01 vs DRC/FP). Contudo TAM e BMP7 aumentaram significativamente a expressão de SMAD 7 (2,8±0,5 e 3,7±0,5 UI, respectivamente; p < 0,01 vs DRC/FP), uma proteína contra reguladora da via do TGF-beta, capaz de bloquear a expressão de fatores pró-fibróticos bem como de fatores inflamatórios. Finalmente, os grupos tratados TAM e BMP7 tiveram a função do peritônio preservada quando comparados aos grupos FP e DRC/FP, verificado pela manutenção da capacidade de ultrafiltração e de reduzir a MTG. Em resumo, tamoxifeno e BMP7 foram capazes de bloquear o espessamento da membrana peritoneal, proteger o peritônio contra a infiltração de células inflamatórias e de miofibroblastos, além de diminuir a proliferação celular no peritônio. Estes tratamentos também foram eficazes em diminuir significativamente a expressão dos fatores pró-fibróticos e das citocinas inflamatórias. Com relação às SMADs, os tratamentos com TAM e BMP7 foram eficazes em bloquear a expressão de SMAD 3, bem como aumentar a expressão de SMAD 7. Os resultados do presente estudo sugerem que tamoxifeno e BMP7 protegem o peritônio no modelo de fibrose peritoneal desenvolvido em ratos com DRC e uremia, possivelmente devido aos seus efeitos anti-inflamatórios e anti-fibróticos / Peritoneal dialysis is an important therapeutic option for patients with stage 5 chronic kidney disease (CKD). However, at medium and long term, morphological and functional changes related to various factors such as bioincompatibility of dialysis solutions and peritoneal infections, among others, establish an inflammatory and fibrotic process in the peritoneal membrane, leading to a loss of dialysis efficiency. The uremic state of these patients aggravates this situation because it intensifies inflammation of the peritoneal membrane. Therapeutic strategies that slow the process of fibrosis of the peritoneal membrane of patients with CKD on dialysis are extremely important. In this context, the present study aimed to establish a model of peritoneal fibrosis associated with CKD with uremia, that mimics the clinical situation, and analyze the effect of two antifibrotic molecules, tamoxifen (TAM) and the BMP7 (bone morphogenic protein-7), in the proposed model. CKD with uremia was induced in male Wistar rats by adenine in the diet during a period of 30 days. After 15 days, with the state of uremia already established, animals received intraperitoneal injections of chlorhexidine gluconate, for the induction of peritoneal fibrosis (PF). Treatment with TAM (10mg/Kg/day by gavage) and BMP7 (30ug/Kg, intraperitoneal injections every 3 days) were initiated along with the induction of peritoneal fibrosis. Six groups were induced: CONTROL, normal animals; CKD, animals with chronic kidney disease; PF, animals with peritoneal fibrosis; CKD / PF, animals with CKD and PF mimicking the clinical situation; CKD / PF + TAM, animals with CKD and PF treated with tamoxifen; and CKD / PF + BMP7, animals with CKD and PF treated with BMP7. During 30 days of the follow-up study, weight, blood pressure, serum urea and creatinine of the animals were verified. At the end of this period, the animals were sacrificed and the peritoneum was removed and subjected to the following analysis: a) histology, to assess the degree of thickening (Masson\'s Trichrome); b) immunohistochemistry, to locate and quantify the presence of inflammatory cells (macrophages, T lymphocytes), myofibroblasts (alfa-smoth muscle actin) and cell proliferation activity (PCNA); c) analysis of pro-inflammatory cytokines (TNF-alfa, IL-1beta and IL-6) both in peritoneal tissue mRNA level through real time PCR as well as on protein level by multiplex; d) real-time PCR to determine the expression of extracellular matrix components (collagen III and fibronectin) and fibrogenic factors (TGF-beta and FSP-1). Furthermore, in order to study the possible signaling pathway associated to peritoneal fibrosis, the expression of SMAD 3 and SMAD 7 in the peritoneum was analyzed via real-time PCR and immunohistochemistry for phosphorylated SMAD 3. Finally, the peritoneal function was assessed by ultrafiltration and mass transferred glucose test (MTG). Data from weight gain showed that while animals from CONTROL and PF groups had significant weight gain (28% and 18% respectively) compared to the first day of protocol, the animals of other groups lost weight significantly, on average, 26% compared to the first day. All animals that received diet rich in adenine developed CKD presented by hypertension, detected on days 15 and 30 of the study (average of 173mmHg and 172mmHg respectively). Confirming the establishment of CKD with uremia, the animals that received diet rich in adenine showed serum urea (average 170 mg/dL on day 15 and 286 mg/dL on day 30) and creatinine (average of 0.97 mg/dL on day 15 and 1.82 mg/dL on day 30) significantly higher in the 15th and 30th days. Treatments with TAM and BMP7 did not influence these parameters. The peritoneal membrane analysis of PF and CKD/PF experimental groups showed a significant thickening of the peritoneal membrane (130 ± 33?m and 132 ± 26?m, respectively; p < 0.001 vs 36 ± 2um and 27 ± 6?m in CONTROL and CKD; p < 0.001) with presence of inflammatory cells. The treatments with TAM and BMP7 were effective in protecting the membrane against the thickening (42 ± 2um and 53±7um, respectively; p < 0.001 vs CKD/PF) and inflammatory infiltrate. Furthermore, with regard to myofibroblasts, effectors cells in the fibrogenesis process detected by alfa-SMA presence, it was found a signicantly expression in the peritoneum of PF and CKD/PF (p < 0.01 vs CONTROLE), and the treatment with TAM and BMP7 significantly protected against the presence of myofibroblasts confirmed by the significantly expression of PCNA. With regard to the detection of pro-inflammatory cytokines, analysis by real-time PCR in the animals of CKD group showed a significant increase in TNF-alfa expression in the peritoneum and IL-1beta compared to the CONTROL group. The expression of these cytokines was also increased in the peritoneum of the CKD/PF group. The treatment with TAM and BMP7 significantly reduced TNF-alfa and IL-1beta expression compared to CKD/PF group (p < 0.01).The repercussion of these results can be observed with the multiplex test in which the presence of these cytokines in its protein form were found in significant quantities in the peritoneum of the animals with uremia associated with PF compared to CONTROL group. The treatment with TAM and BMP7 significantly reduced the presence of these cytokines (p < 0.01 vs CKD/PF). As expected, the mRNA expression of extracellular matrix components was significantly elevated in the PF group and CKD/PF compared to the control group. Indeed, collagen III mRNA expression was higher in PF and CKD/PF group (3.4 ± 1 and 10.3 ± 2.4 UI, respectively; p < 0.01 vs CONTROL) as well as fibronectin (6.5 ± 0.8 and 29.2 ± 1 UI; respectively; p < 0.01 vs CONTROL). The animals treated with TAM and BMP7 significantly blocked the expression of collagen III (1.5 ± 0.9 and 0.2 ± 0.1 UI, respectively; p < 0.01 vs CKD/PF) and fibronectin (6.6±1.2 and 9.7±0.5 UI, respectively; p < 0.01 vs CKD/PF). Further, while in the PF and CKD/PF groups the expression of TGF-beta (13.2 ± 0.9 UI and 30.3 ± 0.1 UI, respectively; p < 0.01) was significantly higher compared to the CONTROL group, TAM and BMP7 decreased the expression of TGF-beta (17.7 ± 0.2 UI and 16.2 ± 0.1UI, respectively; p < 0.01 vs CKD/PF). A similar trend was found with the expression of FSP-1 mRNA with an increase in expression of this gene in PF and CKD/PF groups (p < 0.01 vs CONTROL), with significant blockage in the animals treated with TAM and BMP7 (p < 0.01 vs CKD/PF). Regarding the analysis of signaling pathways possibly involved in the process, SMAD 3 expression was significantly higher in PF and CKD/PF groups (3.7 ± 0.3 UI and 4.6 ± 0.3 UI, respectively) compared to groups CONTROL and CKD (1 ± 0.2 UI and 1.3 ± 0.6 UI, respectively; p < 0,01). Treatments with TAM and BMP7 decreased the expression of SMAD 3 in the peritoneum (1.1 ± 0.6 UI and 1.1 ± 0.7 UI, respectively; p < 0.01 vs CKD/PF). Yet TAM and BMP7 significantly increased the expression of SMAD 7 (2.8 ± 0.5 and 3.7 ± 0.5, respectively; p < 0.01 vs CKD/PF), a regulatory TGF-beta protein capable of blocking the expression of pro-fibrotic and inflammatory factors. Finally, the treated groups had the function of the peritoneum preserved when compared to the PF and CKD / PF groups, checked through the maintenance of the ultrafiltration capacity and reducing MTG. In summary, the animals treated with TAM and BMP7 had the peritoneum protected from thickening, inflammatory infiltrate, presence of myofibroblasts and cellular proliferation. The treatments were also effective in significantly reduce the expression of pro-fibrotic factors and inflammatory cytokines. Regarding SMADs, treatments with TAM and BMP7 were effective in blocking the expression of SMAD 3 and increase SMAD 7 expression. The results of this study suggest that tamoxifen and BMP7 protected the peritoneum in an experimental model of peritoneal fibrosis developed in uremic rats with CKD, possibly due to their anti-inflammatory and anti-fibrotic properties

O acúmulo de lipídeos associado à obesidade, resistência à insulina (RI) e diabetes mellitus tipo 2 (DM2) pode levar ao desenvolvimento de danos renais, e diversos mecanismos podem estar envolvidos neste processo, dentre os quais: 1) redução na atividade da proteína ativada por AMP (AMPK); 2) hiperativação do sistema renina angiotensina (SRA) e consequente aumento na produção de angiotensina II (Ang II). O treinamento físico aeróbio (TFA) promove melhora metabólica significativa, no entanto, pouco se sabe sobre os mecanismos celulares induzidos pelo TFA contra o desenvolvimento de danos renais associados com doenças metabólicas. Sendo assim, o objetivo deste estudo foi avaliar o potencial do TFA para a prevenção de danos renais induzidos por dieta de cafeteria, e a participação do SRA e da proteína AMPK nessa resposta. Para isso, camundongos machos adultos C57BL6/J foram separados em grupos (n=13/grupo) sedentários (SED) alimentados com dieta normocalórica (NO) ou de cafeteria (CAF) (SED-NO e SED-CAF, respectivamente) e treinados (TF) alimentados com dieta NO ou CAF (TF-NO e TF-CAF, respectivamente). O TFA foi realizado a 60% da capacidade máxima, simultaneamente com as dietas durante 8 semanas. A dieta de cafeteria causou maior adiposidade, intolerância à glicose e RI no grupo SED-CAF, enquanto o TFA preveniu esses prejuízos no grupo TF-CAF. Os animais SED-CAF apresentaram 88% de aumento no ritmo de filtração glomerular (RFG), maior deposição lipídica renal e redução do espaço de Bowman comparado ao SED-NO, as quais foram prevenidas no grupo TF-CAF. Não houve alteração no conteúdo de colágeno IV e fibronectina, entretanto o TNF-alfa aumentou em ambos os grupos alimentados com dieta de cafeteria. Houve aumento de 27% da expressão proteica da p-AMPK no grupo TF-CAF, sem diferenças na expressão de t-ACC, p-ACC, PGC1-alfa e SIRT-1. A expressão gênica do SREBP-1 não diferiu entre os grupos, porém a expressão do SREBP-2 aumentou nos grupos SED-CAF e TF-CAF comparado aos grupos SED-NO e TF-NO. No soro, apenas a atividade da ECA2 aumentou nos grupos TF-NO e TF-CAF comparados aos sedentários. No rim, a atividade da ECA aumentou 46% no grupo SED-CAF comparado ao SED-NO, e o TFA foi capaz de prevenir esse aumento. No entanto, a Ang II renal aumentou nos grupos SED-CAF, TF-NO e TF-CAF comparados ao grupo SED-NO. Não houve diferença nos componentes do SRA ECA2/Ang 1-7/Mas renal. Em conclusão, o TFA preveniu os danos renais causados pela dieta de cafeteria, tais como acúmulo de lipídeos nos rins, aumento do RFG e redução do espaço de Bowman, e essa resposta está associada, pelo menos em parte, com a maior ativação da AMPK independente da contribuição do SRA / Lipid accumulation observed in the obesity, insulin resistance (IR) and Diabetes Mellitus type 2 (DM2) may lead to the development of renal damage, and several mechanisms may be involved in this process, such as: 1) reduction in the AMP-activated protein (AMPK) activity; 2) hyperactivation of the renin angiotensin system (RAS) and consequent increase in the production of Angiotensin II (Ang II). Aerobic exercise training (AET) promotes significant metabolic improvement, however, little is known about the cellular mechanisms induced by AET against the development of kidney damage associated with metabolic diseases. Thus, the present study aimed to evaluate the potential of AET to prevent kidney damage induced by cafeteria diet, and the participation of RAS and AMPK protein in this response. Adult male C57BL6/J mice were separated into sedentary (SED) groups fed a normocaloric (NO) or cafeteria (CAF) (SED-NO and SED-CAF, respectively) and trained (TF) fed a NO or CAF diet (TF-NO and TF-CAF, respectively). The AET was performed at 60% of the maximum capacity simultaneously with the diets during 8 weeks. The cafeteria diet induced adiposity increase, glucose intolerance and IR, while AET prevented these changes. Animals SED-CAF increased 88% of glomerular filtration rate (GFR), increased renal lipid deposition and reduced Bowman\'s space compared to SED-NO, which were prevented by AET in the TF-CAF group. There was no change in the collagen IV and fibronectin, however TNF-alpha increased in both cafeteria diet fed groups. There was a 27% increase in the protein p-AMPK expression in the TF-CAF group, with no changes in t-ACC, p-ACC, PGC1-alpha and SIRT-1 expression. The SREBP-1 gene expression did not change among groups, but SREBP-2 gene expression increased in the SED-CAF and TF-CAF groups compared to the SED-NO and TF-NO groups. In the serum, only the activity of ACE 2 increased in TF-NO and TF-CAF groups compared to sedentary groups. In the kidney, ACE activity increased 46% in the SED-CAF group compared to SED-NO, nevertheless the AET was able to prevent this increase. Renal Ang II concentration increased in SED-CAF, TF-NO and TF-CAF groups compared to the SED-NO. No differences were observed in the components of renal RAS ACE2/Ang 1-7/Mas. In conclusion, AET prevented the renal damage caused by cafeteria diet, such as lipid accumulation, increased GFR and reduced Bowman space, and these responses are associated, at least in part, with greater activation of the AMPK protein independent of the RAS contribution