LUIZ FERNANDO ONUCHIC
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Clínica Médica, Faculdade de Medicina - Docente
LIM/29 - Laboratório de Nefrologia Celular, Genética e Molecular, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/29 - Laboratório de Nefrologia Celular, Genética e Molecular, Hospital das Clínicas, Faculdade de Medicina - Líder
7 resultados
Resultados de Busca
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- Molecular and cellular pathogenesis of autosomal dominant polycystic kidney disease(2011) BASTOS, A. P.; ONUCHIC, L. F.Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common human life-threatening monogenic disorders. The disease is characterized by bilateral, progressive renal cystogenesis and cyst and kidney enlargement, often leading to end-stage renal disease, and may include extrarenal manifestations. ADPKD is caused by mutation in one of two genes, PKD1 and PKD2, which encode polycystin-1 (PC1) and polycystin-2 (PC2), respectively. PC2 is a non-selective cation channel permeable to Ca(2+), while PC1 is thought to function as a membrane receptor. The cyst cell phenotype includes increased proliferation and apoptosis, dedifferentiation, defective planar polarity, and a secretory pattern associated with extracellular matrix remodeling. The two-hit model for cyst formation has been recently extended by the demonstration that early gene inactivation leads to rapid and diffuse development of renal cysts, while inactivation in adult life is followed by focal and late cyst formation. Renal ischemia/reperfusion, however, can function as a third hit, triggering rapid cyst development in kidneys with Pkd1 inactivation induced in adult life. The PC1-PC2 complex behaves as a sensor in the primary cilium, mediating signal transduction via Ca(2+) signaling. The intracellular Ca(2+) homeostasis is impaired in ADPKD, being apparently responsible for the cAMP accumulation and abnormal cell proliferative response to cAMP. Activated mammalian target for rapamycin ( mTOR) and cell cycle dysregulation are also significant features of PKD. Based on the identification of pathways altered in PKD, a large number of preclinical studies have been performed and are underway, providing a basis for clinical trials in ADPKD and helping the design of future trials.
- Disruption of polycystin-1 cleavage leads to cardiac metabolic rewiring in mice(2022) AMARAL, Andressa G.; SILVA, Camille C. C. da; SERNA, Julian D. C.; HONORATO-SAMPAIO, Kinulpe; FREITAS, Jessica A.; DUARTE-NETO, Amaro N.; BLOISE, Antonio C.; CASSINA, Laura; YOSHINAGA, Marcos Y.; CHAVES-FILHO, Adriano B.; QIAN, Feng; MIYAMOTO, Sayuri; BOLETTA, Alessandra; BORDIN, Silvana; KOWALTOWSKI, Alicia J.; ONUCHIC, Luiz F.Cardiovascular manifestations account for marked morbi-mortality in autosomal dominant polycystic kidney disease (ADPKD). Pkd1- and Pkd2-deficient mice develop cardiac dysfunction, however the underlying mechanisms remain largely unclear. It is unknown whether impairment of polycystin-1 cleavage at the G-proteincoupled receptor proteolysis site, a significant ADPKD mutational mechanism, is involved in this process. We analyzed the impact of polycystin-1 cleavage on heart metabolism using Pkd1V/V mice, a model unable to cleave this protein and with early cardiac dysfunction. Pkd1V/V hearts showed lower levels of glucose and amino acids and higher lipid levels than wild-types, as well as downregulation of p-AMPK, p-ACC beta, CPT1B-Cpt1b, Ppara, Nppa and Acta1. These findings suggested decreased fatty acid beta-oxidation, which was confirmed by lower oxygen consumption by Pkd1V/V isolated mitochondria using palmitoyl-CoA. Pkd1V/V hearts also presented increased oxygen consumption in response to glucose, suggesting that alternative substrates may be used to generate energy. Pkd1V/V hearts displayed a higher density of decreased-size mitochondria, a finding associated with lower MFN1, Parkin and BNIP3 expression. These derangements were correlated with increased apoptosis and inflammation but not hypertrophy. Notably, Pkd1V/V neonate cardiomyocytes also displayed shifts in oxygen consumption and p-AMPK downregulation, suggesting that, at least partially, the metabolic alterations are not induced by kidney dysfunction. Our findings reveal that disruption of polycystin-1 cleavage leads to cardiac metabolic rewiring in mice, expanding the understanding of heart dysfunction associated with Pkd1 deficiency and likely with human ADPKD.
- Two cases of fungal cyst infection in ADPKD: is this really a rare complication?(2019) ONUCHIC, Laura; SATO, Victor Augusto Hamamoto; NEVES, Precil Diego Miranda de Menezes; BALBO, Bruno Eduardo Pedroso; PORTELA-NETO, Antonio Abel; FERREIRA, Fernanda Trani; WATANABE, Elieser Hitoshi; WATANABE, Andreia; ALMEIDA, Maria Claudia Stockler de; TESTAGROSSA, Leonardo de Abreu; CHOCAIR, Pedro Renato; ONUCHIC, Luiz FernandoBackground: Cyst infection is a prevalent complication in autosomal dominant polycystic kidney disease (ADPKD) patients, however therapeutic and diagnostic approaches towards this condition remain unclear. The confirmation of a likely episode of cyst infection by isolating the pathogenic microorganism in a clinical scenario is possible only in the minority of cases. The available antimicrobial treatment guidelines, therefore, might not be appropriate to some patients. Case presentation: We describe two unique cases of kidney cyst infection by Candida albicans, a condition that has not been previously described in literature. Both cases presented clear risk factors for Candida spp. infection. However, since there was no initial indication of cyst aspiration and culture, antifungal therapy was not immediately started and empirical treatment was initiated as recommended by the current guidelines. Antifungal treatment was instituted in both cases along the clinical course, according to their specificities. Conclusion: Our report highlights the possibility of Candida spp. cyst infection. Failure of clinical improvement with antibiotics should raise the suspicion of a fungal infection. Identification of infected cysts should be pursued in such cases, particularly with PET-CT, and when technically possible followed by cyst aspiration and culture to guide treatment. Risk factors for this condition, such as Candida spp. colonization, previous antimicrobial therapy, hemodialysis, necrotizing pancreatitis, gastrointestinal/hepatobiliary surgical procedure, central venous catheter, total parenteral nutrition, diabetes mellitus and immunodeficiency (neutropenia < 500 neutrophils/mL, hematologic malignancy, chemotherapy, immunosuppressant drugs), should be also considered accepted criteria for empirical antifungal therapy.
- Functional Budd-Chiari Syndrome Associated With Severe Polycystic Liver Disease(2017) NEVES, Precil Diego Miranda de Menezes; BALBO, Bruno Eduardo Pedroso; WATANABE, Elieser Hitoshi; ROCHA-SANTOS, Vinicius; ANDRAUS, Wellington; D'ALBUQUERQUE, Luiz Augusto Carneiro; ONUCHIC, Luiz FernandoA 50-year-old woman with end-stage renal disease secondary to autosomal dominant polycystic kidney disease was referred to a quaternary care center due to significantly increased abdominal girth. Her physical examination revealed tense ascites and abdominal collateral veins. A 10-L paracentesis improved abdominal discomfort and disclosed a transudate, suggestive of portal hypertension. A computed tomographic scan revealed massive hepatomegaly caused by multiple cysts of variable sizes, distributed throughout all hepatic segments. Contrast-enhanced imaging uncovered extrinsic compression of hepatic and portal veins, resulting in functional Budd-Chiari syndrome and portal hypertension. Although image-guided drainage followed by sclerosis of dominant cysts could potentially lead to alleviation of the extrinsic compression, the associated significant risk of cyst hemorrhage and infection precluded this procedure. In this scenario, the decision was to submit the patient to a liver-kidney transplantation. After 1 year of this procedure, the patient maintains normal liver and kidney function and refers significant improvement in quality of life.
- Cyst infection in hospital-admitted autosomal dominant polycystic kidney disease patients is predominantly multifocal and associated with kidney and liver volume(2014) BALBO, B. E. P.; SAPIENZA, M. T.; ONO, C. R.; JAYANTHI, S. K.; DETTONI, J. B.; CASTRO, I.; ONUCHIC, L. F.Positron-emission tomography/computed tomography (PET/CT) has improved cyst infection (CI) management in autosomal dominant polycystic kidney disease (ADPKD). The determinants of kidney and/or liver involvement, however, remain uncertain. In this study, we evaluated clinical and imaging factors associated with CI in kidney (KCI) and liver (LCI) in ADPKD. A retrospective cohort study was performed in hospital-admitted ADPKD patients with suspected CI. Clinical, imaging and surgical data were analyzed. Features of infected cysts were evaluated by PET/CT. Total kidney (TKV) and liver (TLV) volumes were measured by CT-derived multiplanar reconstruction. CI was detected in 18 patients who experienced 24 episodes during an interval of 30 months (LCI in 12, KCI in 10 and concomitant infection in 2). Sensitivities of CT, magnetic resonance imaging and PET/CT were 25.0, 71.4, and 95.0%. Dysuria (P<0.05), positive urine culture (P<0.01), and previous hematuria (P<0.05) were associated with KCI. Weight loss (P<0.01) and increased C-reactive protein levels (P<0.05) were associated with LCI. PET/CT revealed that three or more infected cysts were present in 70% of the episodes. TKV was higher in kidney-affected than in LCI patients (AUC=0.91, P<0.05), with a cut-off of 2502 mL (72.7% sensitivity, 100.0% specificity). TLV was higher in liver-affected than in KCI patients (AUC=0.89, P<0.01) with a cut-off of 2815 mL (80.0% sensitivity, 87.5% specificity). A greater need for invasive procedures was observed in LCI (P<0.01), and the overall mortality was 20.8%. This study supports PET/CT as the most sensitive imaging method for diagnosis of cyst infection, confirms the multifocal nature of most hospital-admitted episodes, and reveals an association of kidney and liver volumes with this complication.
- International Multi-Specialty Delphi Survey: Identification of Diagnostic Criteria for Hepatic and Renal Cyst Infection(2016) LANTINGA, Marten A.; DARDING, Alexander J. M.; SEVAUX, Ruud G. L. de; ALAM, Ahsan; BLEEKER-ROVERS, Chantal P.; BOBOT, Mickael; GALL, Emilie Cornec-Le; GEVERS, Tom J. G.; HASSOUN, Ziad; MEIJER, Esther; MRUG, Michal; NEVENS, Frederik; ONUCHIC, Luiz F.; PEI, York; PICCOLI, Giorgina B.; PIRSON, Yves; RANGAN, Gopala K.; TORRA, Roser; VISSER, Folkert W.; JOURET, Francois; KANAAN, Nada; OYEN, Wim J. G.; SUWABE, Tatsuya; TORRES, Vicente E.; DRENTH, Joost P. H.Background: Cyst infection is one of the complications of autosomal dominant polycystic kidney disease and polycystic liver disease. The diagnosis is typically made on a mix of clinical, laboratory and imaging abnormalities but the importance of individual items is uncertain. We aimed to perform a Delphi survey amongst physicians to achieve consensus on diagnostic criteria. Methods: We retrieved diagnostic items from the literature and conducted physician and patient interviews. All items were combined to create the online questionnaire. Participants rated each item during 3 consecutive rounds. Items were rated for diagnostic helpfulness for hepatic and renal cyst infection on a 9-point scale with anchors, from extremely unimportant (n = 1) to extremely important (n = 9). We determined consensus with the disagreement index. The median rating of each item was calculated and categorized into inappropriate (<= 3.4), uncertain (3.5-6.4) or appropriate (>= 6.5). By combining all items that reached an appropriate consensus rating, we developed a diagnostic algorithm based on expert consensus. Results: We invited 58 physicians to participate in the survey. In total, 35 (60%) responded to round 1 of which 91% (n = 32) and 86% (n = 30) responded to round 2 and 3, respectively. The final panel included 23 nephrologists, 5 hepatologists, a nuclear medicine specialist and an infectious disease physician from 11 countries (male 67%, mean age 47 +/- 11 years, median clinical experience 21 years). The panel rated the diagnostic helpfulness of 59 potential items. Ultimately, 22 hepatic and 26 renal items were rated appropriate, including positive blood cultures and fluorodeoxyglucose positron-emission CT imaging. Ultrasonography and absence of intracystic bleeding were amongst those deemed uncertain or inappropriate. Subsequently, by combining items rated appropriate, we developed a clinical tool to diagnose hepatic and renal cyst infection. Conclusions: We identified diagnostic items for hepatic and renal cyst infection and developed an expert-based diagnostic algorithm, which may aid physicians in the diagnostic work-up. A prospective study is necessary to validate this algorithm. (C) 2016 S. Karger AG, Basel
- Regulation of CFTR Expression and Arginine Vasopressin Activity Are Dependent on Polycystin-1 in Kidney-Derived Cells(2016) BARBOSA, Carolina Monteiro de Lemos; SOUZA-MENEZES, Jackson; AMARAL, Andressa Godoy; ONUCHIC, Luiz Fernando; CEBOTARU, Liudmila; GUGGINO, William B.; MORALES, Marcelo M.Background: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development of multiple, progressive, fluid-filled renal cysts that distort the renal parenchyma, leading to end-stage renal failure, mainly after the fifth decade of life. ADPKD is caused by a mutation in the PKD1 or PKD2 genes that encode polycystin-1 (PC-1) and polycystin-2 (PC-2), respectively. PC-1 is an important regulator of several signaling pathways and PC-2 is a nonselective calcium channel. The CFTR chloride channel is responsible for driving net fluid secretion into the cysts, promoting cyst growth. Arginine vasopressin hormone (AVP), in turn, is capable of increasing cystic intracellular cAMP, contributing to cell proliferation, transepithelial fluid secretion, and therefore to disease progression. The aim of this study was to assess if AVP can modulate CFTR and whether PC-1 plays a role in this potential modulation. Methods: M1 cells, derived from mouse cortical collecting duct, were used in the current work. The cells were treated with 10(-7) M AVP hormone and divided into two main groups: transfected cells superexpressing PC-1 (Transf) and cells not transfected (Ctrl). CFTR expression was assessed by immunodetection, CFTR mRNA levels were quantified by quantitative reverse transcription-polymerase chain reaction, and CFTR net ion transport was measured using the Ussing chamber technique. Results: AVP treatment increased the levels of CFTR protein and mRNA. CFTR short-circuit currents were also increased. However, when PC-1 was overexpressed in M1 cells, no increase in any of these parameters was detected. Conclusions: CFTR chloride channel expression is increased by AVP in M1 cells and PC-1 is capable of regulating this modulation.