Identification and Properties of TRPV4 Mutant Channels Present in Polycystic Kidney Disease Patients.

Polycystic kidney disease (PKD), a disease characterized by the enlargement of the kidney through cystic growth is the fourth leading cause of end-stage kidney disease world-wide. Transient receptor potential Vanilloid 4 (TRPV4), a calcium-permeable TRP, channel participates in kidney cell physiology and since TRPV4 forms complexes with another channel whose malfunction is associated to PKD, TRPP2 (or PKD2), we sought to determine whether patients with PKD, exhibit previously unknown mutations in TRPV4. Here, we report the presence of mutations in the TRPV4 gene in patients diagnosed with PKD and determine that they produce gain-of-function (GOF). Mutations in the sequence of the TRPV4 gene have been associated to a broad spectrum of neuropathies and skeletal dysplasias but not PKD, and their biophysical effects on channel function have not been elucidated. We identified and examined the functional behavior of a novel E6K mutant and of the previously known S94L and A217S mutant TRVP4 channels. The A217S mutation has been associated to mixed neuropathy and/or skeletal dysplasia phenotypes, however, the PKD carriers of these variants had not been diagnosed with these reported clinical manifestations. The presence of certain mutations in TRPV4 may influence the progression and severity of PKD through GOF mechanisms. PKD patients carrying TRVP4 mutations are putatively more likely to require dialysis or renal transplant as compared to those without these mutations.

Evolution of ion channels in cetaceans: a natural experiment in the tree of life.

Cetaceans represent a natural experiment within the tree of life in which a lineage changed from terrestrial to aquatic habitats. This shift involved phenotypic modifications, representing an opportunity to explore the genetic bases of phenotypic diversity. Among the different molecular systems that maintain cellular homeostasis, ion channels are crucial for the proper physiological functioning of all living species. This study aims to explore the evolution of ion channels during the evolutionary history of cetaceans. To do so, we created a bioinformatic pipeline to annotate the repertoire of ion channels in the genome of the species included in our sampling. Our main results show that cetaceans have, on average, fewer protein-coding genes and a higher percentage of annotated ion channels than non-cetacean mammals. Signals of positive selection were detected in ion channels related to the heart, locomotion, visual and neurological phenotypes. Interestingly, we predict that the NaV1.5 ion channel of most toothed whales (odontocetes) is sensitive to tetrodotoxin, similar to NaV1.7, given the presence of tyrosine instead of cysteine, in a specific position of the ion channel. Finally, the gene turnover rate of the cetacean crown group is more than three times faster than that of non-cetacean mammals.

The genetic spectrum of polycystic kidney disease in children

SUMMARY OBJECTIVE: Autosomal dominant polycystic kidney disease is an inherited kidney disorder with mutations in polycystin-1 or polycystin-2. Autosomal recessive polycystic kidney disease is a severe form of polycystic kidney disease that is characterized by enlarged kidneys and congenital hepatic fibrosis. Mutations at PKHD1 are responsible for all typical forms of autosomal recessive polycystic kidney disease. METHODS: We evaluated the children diagnosed with polycystic kidney disease between October 2020 and May 2022. The diagnosis was established by family history, ultrasound findings, and/or genetic analysis. The demographic, clinical, and laboratory findings were evaluated retrospectively. RESULTS: There were 28 children (male/female: 11:17) evaluated in this study. Genetic analysis was performed in all patients (polycystin-1 variants in 13, polycystin-2 variants in 7, and no variants in 8 patients). A total of 18 variants in polycystin-1 and polycystin-2 were identified and 9 (50%) of them were not reported before. A total of eight novel variants were identified as definite pathogenic or likely pathogenic mutations. There was no variant detected in the PKDH1 gene. CONCLUSION: Our results highlighted molecular features of Turkish children with polycystic kidney disease and demonstrated novel variations that can be utilized in clinical diagnosis and prognosis.

Prevalence of polycystic kidney disease in Persian and Persian-related cats in western Mexico.

OBJECTIVES: Autosomal dominant polycystic kidney disease (ADPKD), the most frequently diagnosed hereditary disease affecting Persian cats, is caused by a cytosine-to-adenine transversion (10063C>A) in PKD1, the gene that codes for polycystin-1. The objective of this study was to provide a preliminary estimate of the frequency of the pathogenic 10063C>A single nucleotide polymorphism (SNP) of PKD1 in Persian and Persian-related cat breeds in western Mexico. METHODS: Blood samples were collected from 104 cats (89 Persian, seven Persian crossbreed, five Siamese and three Himalayan cats). Genotyping was performed with our proposed PCR restriction fragment length polymorphism (RFLP) assay, as well as a previously established PCR-RFLP method for validation. The genotypes of control cats were corroborated by a commercial veterinary genetics laboratory. RESULTS: Our proposed PCR-RFLP assay and the validated PCR-RFLP methodology indicated that 24/104 (23.1%) cats in this study were heterozygous carriers of the 10063C>A SNP, including 23/89 Persian cats (25.8%) and 1/7 Persian crossbreed cats (14.3%). No Siamese or Himalayan cats were carriers. There were no discrepancies between the results obtained with our proposed assay and those obtained with the validation method or with commercial laboratory results. CONCLUSIONS AND RELEVANCE: The carrier frequency of the PKD1 10063C>A SNP in Persian and Persian-related cat breeds in western Mexico was found to be 23.1%. ADPKD frequencies among cat populations in Mexico have not been published previously. Genotyping assays can be used to facilitate the selection of breeding stocks by local breeders and veterinarians to avoid propagation of ADPKD.

Polycystic kidney disease in rough toothed dolphins (Steno bredanensis) found in the Paraná coast, southern Brazil

Background: Renal cystic diseases (RCD) are characterized by cystic structures on renal parenchyma associated withobstructive lesions, membranous disruptions, and/or growth disturbances. The polycystic kidney disease (PKD) showsspecific pathological characteristics, related to mutations on PKD1 and/or PKD2 chromosome locus on humans. In Persiancats and bull terriers the condition is like the human “adult-onset” PKD, while in Perendale sheep the “childhood”-like isdescribed. In cetaceans, RCD are reported, however the characterization of PKD is scarcely described. This report aimsto describe two cases of PKD and one of RCD in stranded Steno bredanensis, and to discuss the disease associated factors.Cases: Four rough-toothed-dolphins were found stranded in the Paraná coast, southern Brazil between 2016 to 2018,through the Santos Basin Beach Monitoring Project (PMP-BS), one of the systematic monitoring programs required byBrazilian Institute of Environment and Renewable Natural Resources (IBAMA) for the environmental licensing processof oil production and transport by Petrobras in the presalt province. In three animals histological sampling was performed.One of them (animal 3) was found alive, presenting altered buoyancy with lateralization to the right and signs of pneumonia. The blood analysis showed anemia and leukocytosis. The animal showed poor clinical prognosis, and even withsupportive treatment, come to death four days after the rescue. Routine autopsies were performed on all animals. Animals1 and 2 presented macroscopically enlarged kidneys containing disseminated cystic...(AU)

Polycystic kidney disease in rough toothed dolphins (Steno bredanensis) found in the Paraná coast, southern Brazil

Background: Renal cystic diseases (RCD) are characterized by cystic structures on renal parenchyma associated withobstructive lesions, membranous disruptions, and/or growth disturbances. The polycystic kidney disease (PKD) showsspecific pathological characteristics, related to mutations on PKD1 and/or PKD2 chromosome locus on humans. In Persiancats and bull terriers the condition is like the human “adult-onset” PKD, while in Perendale sheep the “childhood”-like isdescribed. In cetaceans, RCD are reported, however the characterization of PKD is scarcely described. This report aimsto describe two cases of PKD and one of RCD in stranded Steno bredanensis, and to discuss the disease associated factors.Cases: Four rough-toothed-dolphins were found stranded in the Paraná coast, southern Brazil between 2016 to 2018,through the Santos Basin Beach Monitoring Project (PMP-BS), one of the systematic monitoring programs required byBrazilian Institute of Environment and Renewable Natural Resources (IBAMA) for the environmental licensing processof oil production and transport by Petrobras in the presalt province. In three animals histological sampling was performed.One of them (animal 3) was found alive, presenting altered buoyancy with lateralization to the right and signs of pneumonia. The blood analysis showed anemia and leukocytosis. The animal showed poor clinical prognosis, and even withsupportive treatment, come to death four days after the rescue. Routine autopsies were performed on all animals. Animals1 and 2 presented macroscopically enlarged kidneys containing disseminated cystic...

New mutation associated with autosomal dominant polycystic kidney disease with founder effect located in the alpujarra region of granada. / Nueva mutación asociada a poliquistosis renal autosómica dominante con efecto fundador localizada en la Alpujarra de Granada.

OBJECTIVE: To demonstrate that the variant not described in PKD1 gene c.7292T> A, identified in four families from the Alpujarra in Granada, is the cause of autosomal dominant polycystic kidney disease (ADPKD). This variant consists of a transversion of thymine (T) by adenine (A) that at the level of the Polycystin 1 protein produces a change of leucine (Leu / L) by Glutamine (Gln / Q) in position 2431 (p.Leu2431Gln). METHOD: Sociodemographic and clinical variables were registered using clinical histories, genealogical trees, ultrasounds and genetic analysis to ADPKD and healthy individuals belonging to these families in the context of segregation study. RESULTS: All PKD individuals carried the c.7292T>A variant in heterozygosis, whereas healthy ones did not. Among all ADPKD patients, 62.9% were women. ADPKD diagnosis was made at 29.3 ± 15.82 years, after having the first child in 64.8%. The main reasons for diagnosis were family history and hematuria episodes. The onset of renal replacement therapy (RRT) occurred at 55.8 ± 7.62 years (range 44-67), and death at 63 ± 92.2 years (range 48-76), being the cause unknown, cardiovascular and insufficiency kidney the most frequent; the median of renal survival was established at 58.5 ± 0.77 years and the median survival of patients at 67.2 ± 3.54 years. No differences in kidney and patient survivals were observed according to sex. Among deceased patients, 52.2% required RRT and 94.4% suffered from renal failure. CONCLUSIONS: The variant c.7292T>A in PKD1 gene is responsible for the disease, and its distribution in the Alpujarra region of Granada suggests a founder effect. In ADPKD it is necessary to perform segregation studies that help us to reclassify genetic variants, in this case from indeterminate to pathogenic.

Protein kinase D1 inhibition interferes with mitosis progression.

Protein kinase D1 (PKD1) plays a vital role in signal transduction, cell proliferation, membrane trafficking, and cancer; however, the majority of the studies up to date had centered primarily on PKD1 functions in interphase, very little is known about its role during cell division. We previously demonstrated that during mitosis PKD1 is activated and associated with centrosomes, spindles, and midbodies. However, these observations did not address whether PKD1 was associated with mitosis regulation. Accordingly, we used rapidly acting PKD-specific inhibitors to examine the contribution of PKD1 the sequence of events in mitosis. We found that although PKD1 overexpression did not affect mitosis progression, suppression of its catalytic activity by two structurally unrelated inhibitors (kb NB 142-70 and CRT 0066101) induced a significant delay in metaphase to anaphase transition time. PKD1 inhibition during mitosis also produced the appearance of abnormal spindles, defects in chromosome alignment, and segregation as well as apoptosis. Thus, these observations indicate that PKD1 activity is associated with mitosis regulation.

Caffeine Accelerates Cystic Kidney Disease in a Pkd1-Deficient Mouse Model.

BACKGROUND/AIMS: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst formation and growth, leading to end-stage renal disease. A higher kidney volume is predictive of a more accelerated decline in renal function. This study aimed to examine the effects of caffeine, a phosphodiesterase inhibitor, on the progression of cystic kidney disease in a mouse model orthologous to human disease (Pkd1cond/cond:Nestincre). METHODS: Caffeine was administered to male cystic (CyCaf) and noncystic (NCCaf) mice (Pkd1cond/cond) from conception and at the postweaning period through 12 weeks of life (3 mg/d), while control animals consumed water (CyCtrl and NCCtrl). Renal ultrasonography was performed at 10 weeks of life to calculate total kidney volume and cystic index. At the end of the protocol, blood and urine samples were collected for biochemical analysis, and animals were euthanized. Kidneys were harvested to obtain renal tissue for determinations of adenosine 3´5´-cyclic monophosphate (cAMP) by an enzymatic immunoassay kit and phosphorylated extracellular signal-regulated kinase (p-ERK) by Western blotting. Renal fibrosis (picrosirius staining), renal cell proliferation (ki-67 immunohistochemistry) and apoptotic rates (TUNEL analysis) were also determined. RESULTS: At 12 weeks, CyCaf mice exhibited higher serum urea nitrogen, renal cystic index, total kidney volume, kidney cell proliferation, apoptosis and fibrosis compared with CyCtrl mice. Serum cystatin C was significantly higher in CyCaf than in NCCaf and NCCtrl mice. CyCaf mice had higher total kidney weight than all other groups but not higher heart and liver weight. The levels of cAMP and p-ERK did not differ among the groups. CONCLUSION: Caffeine consumption from conception through 12 weeks led to increased cystic index and total kidney volume and worsened renal function in Pkd1-deficient cystic mice, suggesting that high consumption of caffeine may contribute to a faster progression of renal disease in ADPKD.

Cardiac dysfunction in Pkd1-deficient mice with phenotype rescue by galectin-3 knockout.

Alterations in myocardial wall texture stand out among ADPKD cardiovascular manifestations in hypertensive and normotensive patients. To elucidate their pathogenesis, we analyzed the cardiac phenotype in Pkd1(cond/cond)Nestin(cre) (CYG+) cystic mice exposed to increased blood pressure, at 5 to 6 and 20 to 24 weeks of age, and Pkd1(+/-) (HTG+) noncystic mice at 5-6 and 10-13 weeks. Echocardiographic analyses revealed decreased myocardial deformation and systolic function in CYG+ and HTG+ mice, as well as diastolic dysfunction in older CYG+ mice, compared to their Pkd1(cond/cond) and Pkd1(+/+) controls. Hearts from CYG+ and HTG+ mice presented reduced polycystin-1 expression, increased apoptosis, and mild fibrosis. Since galectin-3 has been associated with heart dysfunction, we studied it as a potential modifier of the ADPKD cardiac phenotype. Double-mutant Pkd1(cond/cond):Nestin(cre);Lgals3(-/-) (CYG-) and Pkd1(+/-);Lgals3(-/-) (HTG-) mice displayed improved cardiac deformability and systolic parameters compared to single-mutants, not differing from the controls. CYG- and HTG- showed decreased apoptosis and fibrosis. Analysis of a severe cystic model (Pkd1(V/V); VVG+) showed that Pkd1(V/V);Lgals3(-/-) (VVG-) mice have longer survival, decreased cardiac apoptosis and improved heart function compared to VVG+. CYG- and VVG- animals showed no difference in renal cystic burden compared to CYG+ and VVG+ mice. Thus, myocardial dysfunction occurs in different Pkd1-deficient models and suppression of galectin-3 expression rescues this phenotype.

Identificação da presença da mutação do gene da PKD não associada a CMH em gatos Persas - relato de caso / Identification of the presence of the mutation of the gene of PKD not associated with mutation of MYBPC3-A31P of HCM in Persian cats - Case Report

A doença renal policística (PKD) é uma doença hereditária autossômica dominante que acomete principalmente gatos da raça Persa sendo importante causa de doença renal crônica nesta espécie. A miocardiopatia hipertrófica (CMH) é a doença cardíaca mais comum de gatos, com evidência de origem genética em algumas raças. Apesar de serem doenças frequentemente descritas em gatos, segundo a literatura revisada, este é o primeiro relato da ocorrência concomitante de PKD e CMH em gatos da raça Persa no Brasil.(AU)

Polycystic kidney disease (PKD) is a hereditary autosomal dominant disorder that mainly affects Persian cats; it is an important cause of chronic kidney disease in this species. Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, and there is evidence of a genetic origin in some breeds. Although neither of these disorders is rare in cats, according to our literature review, this is the first report of the concomitant occurrence of PKD and HCM in Persian cats in Brazil.(AU)

Identificação da presença da mutação do gene da PKD não associada a CMH em gatos Persas - relato de caso / Identification of the presence of the mutation of the gene of PKD not associated with mutation of MYBPC3-A31P of HCM in Persian cats - Case Report

A doença renal policística (PKD) é uma doença hereditária autossômica dominante que acomete principalmente gatos da raça Persa sendo importante causa de doença renal crônica nesta espécie. A miocardiopatia hipertrófica (CMH) é a doença cardíaca mais comum de gatos, com evidência de origem genética em algumas raças. Apesar de serem doenças frequentemente descritas em gatos, segundo a literatura revisada, este é o primeiro relato da ocorrência concomitante de PKD e CMH em gatos da raça Persa no Brasil.

Polycystic kidney disease (PKD) is a hereditary autosomal dominant disorder that mainly affects Persian cats; it is an important cause of chronic kidney disease in this species. Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, and there is evidence of a genetic origin in some breeds. Although neither of these disorders is rare in cats, according to our literature review, this is the first report of the concomitant occurrence of PKD and HCM in Persian cats in Brazil.

Identification, localization, and quantification of neuronal cell membrane receptors with plasmonic probes: role of protein kinase D1 in their distribution.

Detecting, imaging, and being able to localize the distribution of several cell membrane receptors on a single neuron are very important topics in neuroscience research. In the present work, the distribution of metabotropic glutamate receptor 1a (mGluR1a) density on neuron cells on subcellular length scales is determined by evaluating the role played by protein kinase D1 (PKD1) in the trafficking of membrane proteins, comparing the distribution of mGluR1a in experiments performed in endogenous PKD1 expression with those in the presence of kinase-inactive protein kinase D1 (PKD1-kd). The localization, distribution, and density of cell surface mGluR1a were evaluated using 90 nm diameter Au nanoparticle (NP) probes specifically functionalized with a high-affinity and multivalent labeling function, which allows not only imaging NPs where this receptor is present but also quantifying by optical means the NP density. This is so because the NP generates a density (ρ)-dependent SERS response that facilitated a spatial mapping of the mGluR1a density distribution on subcellular length scales (dendrites and axons) in an optical microscope. The measured ρ values were found to be significantly higher on dendrites than on axons for endogenous PKD1, while an increase of ρ on axons was observed when PKD1 is altered. The spatial distribution of the NP immunolabels through scanning electron microscopy (SEM) confirmed the results obtained by fluorescence bright-field analysis and dark-field spectroscopy and provided additional structural details. In addition, it is shown using electrodynamic simulations that SERS spectroscopy could be a very sensitive tool for the spatial mapping of cell membrane receptors on subcellular length scales, as SERS signals are almost linearly dependent on NP density and therefore give indirect information on the distribution of cell membrane proteins. This result is important since the calibration of the ρ-dependent near-field enhancement of the Au immunolabels through correlation of SERS and SEM paves the way toward quantitative immunolabeling studies of cell membrane proteins involved in neuron polarity. From the molecular biology point of view, this study shows that in cultured hippocampal pyramidal cells mGluR1a is predominantly transported to dendrites and excluded from axons. Expression of kinase-inactive protein kinase D1 (PKD1-kd) dramatically and selectively alters the intracellular trafficking and membrane delivery of mGluR1a-containing vesicles.

Regulation of PKD1-mediated Golgi to cell surface trafficking by Gαq subunits.

BACKGROUND INFORMATION: Heterotrimeric GTP-binding proteins play a key role in cell trafficking regulation. Above all, specific Gßγ subunits have been shown to be a major component of a signal transduction pathway, which also involves phospholipases C (PLC), protein kinases C (PKC) and D (PKD), whose main function is to regulate transport between Golgi and plasma membrane. It was the involvement of PLC which led us to study the role of the other member of this G protein family, the α subunits, in the regulation of membrane fission at the Golgi apparatus. RESULTS: Among constitutive active (QL) variants of different G protein α subunit sub-families, only GαqQL subunits were able to induce Golgi fragmentation, a phenotype that mainly reflects a membrane fission increase at this organelle. This phenotype was not observed with a GαqQL palmitoylation mutant, showing the need for a membrane-bounded subunit. Besides, GαqQL-dependent Golgi fission was blocked by specific PLC and PKC inhibitors, and in the presence of a PKD1-kinase dead variant. In addition, GαqQL was the only α subunit capable of inducing PKD1 phosphorylation. Finally, Vesicular Stomatitis Virus thermosensitive mutant glycoprotein (VSVG tsO45) transport assays have demonstrated that GαqQL acts directly on Golgi membranes to regulate trafficking between this organelle and plasma membrane. CONCLUSIONS: All these results indicate Gαq subunits for the first time as a regulator of PKD-mediated intracellular trafficking between Golgi apparatus and plasma membrane, opening new perspectives in the understanding of internal trafficking regulation by external signals through G protein-coupled receptors.

Structure of internalin InlK from the human pathogen Listeria monocytogenes.

Listeria monocytogenes is a human pathogen that employs a wide variety of virulence factors in order to adhere to, invade, and replicate within target cells. Internalins play key roles in processes ranging from adhesion to receptor recognition and are thus essential for infection. Recently, InlK, a surface-associated internalin, was shown to be involved in Listeria's ability to escape from autophagy by recruitment of the major vault protein (MVP) to the bacterial surface. Here, we report the structure of InlK, which harbors four domains arranged in the shape of a "bent arm". The structure supports a role for the "elbow" of InlK in partner recognition, as well as of two Ig-like pedestals intercalated by hinge regions in the projection of InlK away from the surface of the bacterium. The unusual fold and flexibility of InlK could be essential for MVP binding and concealment from recognition by molecules involved in the autophagic process.

Molecular and cellular pathogenesis of autosomal dominant polycystic kidney disease

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 Ca2+, 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 Ca2+ signaling. The intracellular Ca2+ 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.

Doença renal policística do adulto: uma atualização / Adult polycystic kidney disease: an update

A doença renal policística do adulto é uma desordem genética de caráter autossômico dominante, caracterizada por progressivo desenvolvimento e crescimento de cistos renais, que culminam com a falência renal terminal na meia-idade. Outras manifestações clínicas associadas incluem cistos hepáticos e pancreáticos, hipertensão, aneurismas cerebrais e defeitos cardiovasculares. Aspectos celulares e moleculares dos mecanismos de cistogênese envolvem proliferação e apoptose celular, remodelamento da matriz extracelular, secreção e acúmulo de fluidos. Geneticamente heterogênea, na maioria dos casos (aproximadamente 85%) são mutações no gene PKD1, localizado no cromossomo 16p13.3, com o segundo gene, PKD2, localizado nos intervalos do cromossomo 4q13-q23, respondendo por 15% das mutações, ambos já seqüenciados e caracterizados. Existem evidências da interação comum das proteínas policistinas 1 e 2 em rotas de eventos de adesão extracelular e transporte iônico, possibilitando a regulação do fluxo de Ca++ transmembrana. Inúmeros trabalhos vêm tentando correlacionar o genótipo mutado ao fenótipo expresso em termos da progressão e severidade daautosomal dominant polycystic kidney disease. A análise das mutações autosomal dominant polycystic kidney disease é fundamental para a compreensão dos mecanismos de atuação envolvidos na doença. Métodos de detecção baseados na reação em cadeia da polimerase têm sido amplamente empregados, como a reação em cadeia da polimerase via transcriptase reversa, protein truncation test, single-strand conformational polymorphism e denaturing high performance liquid chromatography, importantes ferramentas que auxiliam no seqüenciamento e caracterização dessas mutações

Adult polycystic kidney disease is an autosomal dominant genetic disorder, characterized by progressive development and growth of renal cysts, which result in terminal renal failure in middle age. Other associated clinical manifestations include hepatic and pancreatic cysts, hypertension, cerebral aneurysms and cardiovascular disorders. Cellular and mononuclear aspects of the mechanisms of cytogenesis comprehend cellular proliferation and apoptosis, remodeling of the extracellular matrix, secretion and accumulation of fluids. This disease is genetically heterogeneous; in most cases (approximately 85%), the gene involved is PKD1, which is located on chromosome 16p13.3. In the remaining cases (15%), the disease is caused by mutational changes in another gene (PKD2), which is located at chromosome intervals 4q13-q23. Both genes have been sequenced and characterized. There is evidence of the common interaction of polycystins 1 and 2 in pathways of extracellular adhesion and ionic transportation events, which promotes the regulation of transmembrane Ca++ flow. Several studies have tried to correlate the mutant genotype with the phenotype expressed in terms of progression and severity of the autosomal dominant polycystic kidney disease. Analyzing mutations in the autosomal dominant polycystic kidney disease is crucial for understanding the action mechanisms involved in this disease. Detection methods based on the polymerase chain reaction have been widely used, such as the reverse transcriptase polymerase chain reaction, protein truncation test, single-strand conformational polymorphism, and denaturing high performance liquid chromatography. They are important tools that help sequencing and characterizing those mutations

Cistogênese e a expressão das policistinas nos rins policísticos / Cystogenesis and polycystin expression in polycystic kidneys

A doença renal policística do adulto é uma desordem genética de caráter autossômicodominante, caracterizada pelo progressivo desenvolvimento e crescimento de cistos renais,que podem levar à doença renal terminal durante a fase adulta do indivíduo. Outrasmanifestações clínicas associadas incluem cistos hepáticos e pancreáticos, hipertensão,aneurismas cerebrais e alterações cardiovasculares. Aspectos celulares e moleculares dosmecanismos de cistogênese envolvem proliferação e apoptose celular, remodelamento damatriz extracelular, secreção e acúmulo de líquidos. Geneticamente heterogênea, na maioriados casos (~ 85%) são mutações no gene PKD1, localizado no cromossomo 16p13.3, como segundo gene, PKD2, localizado nos intervalos do cromossomo 4q13-q23, respondendopor 15% de mutações, ambos já seqüenciados e caracterizados, ocorrendo ainda um terceirogene, PKD3, porém ainda pouco estudado. Existem evidências da interação comum dasproteínas policistinas 1 e 2, associadas com proteínas ciliares em rotas de eventos deadesões extracelulares e transportes iônicos, possibilitando a regulação do fluxo de Cl- eCa2+ transmembrana.

Adult polycystic kidney disease is an autosomal dominant genetic disorder, characterizedby progressive development and growth of renal cysts, which may lead to terminal renalfailure during adulthood. Other associated clinical manifestations include hepatic andpancreatic cysts, hypertension, cerebral aneurysms and cardiovascular disorders. Cellularand mononuclear aspects of the mechanisms of cytogenesis comprehend cellular proliferationand apoptosis, remodeling of the extracellular matrix, secretion and accumulation of fluids.This disease is genetically heterogeneous; in most cases (approximately 85%), the geneinvolved is PKD1, which is located on chromosome 16p13.3. In the remaining cases (15%),the disease is caused by mutational changes in another gene (PKD2), which is located atchromosome intervals 4q13-q23. Both genes have been sequenced and characterized. Thereis also a third gene, PKD3, which has been little studied. There is evidence of the commoninteraction of polycystins 1 and 2, associated with ciliary proteins in pathways of extracellularadhesion and ionic transportation events, which promotes the regulation of Cl- andtransmembrane Ca2+ flow.