Mutations In PKD1 Gene Research Articles

Analysis of serum proteomic in cats with polycystic kidney disease-1 gene mutation

Feline autosomal dominant polycystic kidney disease (PKD) is common in Persian and Persian-cross cats. This study aims to investigate proteins that can be potential biomarkers for early disease diagnosis in cats with PKD1 heterozygous gene mutations and compare them with chronic kidney disease cats and normal wild-type cats. Thirty-three client-owned cats of variable breeds (ten PKD1 gene mutation cats, twelve wild-type cats with normal blood profiles, and eleven wild-type cats with chronic renal disease) were enrolled in this study. This study used serum-based proteomic profiling analysis in cats. Abdominal ultrasounds were examined in all cats. Proteomic analysis was conducted by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). One hundred and fifty-nine proteins were significantly differentially expressed between each group. The proteins identified in this study are known to regulate the apoptosis pathway. The apoptosis regulator Bcl-2 (BCL2) was overexpressed in the chronic kidney disease (CKD) group, while apoptotic peptidase activating factor 1 (APAF1) and BCL2-associated X apoptosis regulator (BAX) were only expressed in the PKD group. Ingenuity pathway analysis revealed that proteins uniquely expressed in the PKD group were linked to the Wnt signaling pathway and MAPK pathway. Asparagine synthetase domain-containing and secreted frizzled-related proteins were interesting proteins that should be studied further for the possibility of a candidate protein for disease detection. The proteomic profiles identified in this study could be used as potential novel biomarkers for the early detection of PKD in cats.

#1040 Correlation of genotype to disease onset age and hypertension diagnosis in autosomal dominant polycystic kidney disease

Abstract Background and Aims Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the predominant genetic disease leading to End Stage Kidney Disease (ESKD). Genetic identity could correlate to the disease profile. Correlations between genetic and phenotype characteristics in a cohort of ADPKD patients are investigated. Method Genetic analysis was conducted in 85 patients with an ADPKD phenotype, employing targeted Next Generation (tNGS) or Sanger Sequencing and Multiplex ligation-dependent probe amplification (MLPA). Medical history, clinical and laboratory data, including Renal Magnetic Resonance Imaging (MRI) for Total Kidney Volume (TKV) measurement (in 66 patients), were recorded and subsequently correlated to the respective genotypes. Results Eighty-five patients (43 females, 42 males, 33 ± 16 years old) were included in the study. The mean age at diagnosis of the disease was at 21.5 ± 13 (0.6-69) years. Fifty-eight out of 85 patients (68%) had a familial history of ADPKD. The mean age at which the affected parent reached ESKD was 53.0 ± 9 years. Hypertension was diagnosed in 60 individuals (71%) within the study cohort. The mean age at hypertension diagnosis was 31 ± 11 years. In the assessment based on height-adjusted TKV and age, the Mayo Clinic Imaging Categories revealed that 9% of patients were classified as 1A, 20% as 1B, 29% as 1C, 29% as 1D, and 13% as 1E. Mutations in PKD1 gene were detected in 70 patients (82%), with 61% exhibiting truncating mutations and 39% non-truncating mutations, while PKD2 mutations were identified in 15 patients (18%). The average age of ADPKD diagnosis differed among genetic subgroups. Patients carrying PKD1-truncating mutations were diagnosed at 17.6 ± 11 years, those with PKD1-non-truncating mutations at 24.5 ± 12 years, and those with PKD2 mutations at 27.3 ± 16 years (p = 0.01). Moreover, the mean age at which the affected parent reached ESKD was 50 ± 8 years, 55 ± 10 and 60 ± 7 years in PKD1-truncating, PKD1-non-truncating and PKD2 patients respectively (p = 0.04). Additionally, the mean age of hypertension diagnosis was 29 ± 12 years in PKD1-truncating, 30 ± 10 years in PKD1-non-truncating and 40 ± 7 years in PKD2 patients (p = 0.05). Conclusion Mutation type correlates with the age of ADPKD diagnosis, the renal survival within families and the hypertension onset. Patients with PKD1-truncating mutations manifest an earlier onset of both the disease and hypertension compared to those with PKD2 gene mutations.

Kidney Measurement and Glomerular Filtration Rate Evolution in Children with Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by renal tubular cystic dilatations. The cysts can develop anywhere along the nephron, and over time the cystic dilatation leads to kidney enlargement. On the other hand, the cysts begin to reduce the number of functional nephrons as a consequence of cystic expansion that further contributes to the decline in renal function over the years. The pressure exerted by the dilated cysts leads to compensatory mechanisms that further contribute to the decline in renal function. These structural changes are responsible of glomerular hyperfiltration states, albuminuria, proteinuria, and hematuria. However, the presentation of ADPKD varies in children, from a completely asymptomatic child with incidental ultrasound detection of cysts to a rapidly progressive disease. There have been reports of early onset ADPKD in children younger than 2 years that showed a more rapid decline in renal function. ADPKD is caused by a mutation in PKD1 and PKD2 genes. Today, the PKD1 gene mutation seems to account for up to 85% of the cases worldwide, and it is associated with worse renal outcomes. Individuals with PKD2 gene mutation seem to present a milder form of the disease, with a more delayed onset of end-stage kidney disease. The cardinal sign of ADPKD is the presence of renal cysts during renal ultrasound. The current guidelines provide clinicians the recommendations for genetic testing in children with a positive family history. Given that the vast majority of children with ADPKD present with normal or supra-normal kidney function, we explored the glomerular filtration rates dynamics and the renal ultrasound-adjusted percentiles. In total, 14 out of 16 patients had kidney percentiles over 90%. The gene mutations were equally distributed among our cohort. In addition, we compared the modified Schwartz formula to the quadratic equation after adjusting the serum creatinine measurements. It seems that even though children with ADPKD have enlarged kidneys, the renal function is more likely normal or near normal when the quadratic estimation of glomerular filtration rate is used (qGFR tended to be lower, 111.95 ± 12.43 mL/min/1.73 m2 when compared to Schwartz eGFR 126.28 ± 33.07 mL/min/1.73 m2, p = 0.14). Also, when the quadratic equation was employed, not even a single patient reached the glomerular hyperfiltration threshold. The quadratic formula showed that glomerular filtration rates are linear or slightly decreasing after 1 year of follow-up (quadratic ΔeGFR = -0.32 ± 5.78 mL/min/1.73 m2), as opposed to the Schwartz formula that can falsely classify children in a hyperfiltration state (ΔeGFR = 7.51 ± 19.46 mL/min/1.73 m2), p = 0.019.

PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts

Background Polycystic kidney disease (PKD) has a complex phenotype partly explained by genetic variants related to this disease. Ultrasonography is a promising approach for defining clinical signs. This study aimed to assess kidney characteristics in cats with Polycystin-1 (PKD1) gene mutations and wild-type cats. Kidney characteristics were identified by ultrasonography. Methods A total of 108 cats of variable breeds aged an average of 37.01±3.50 months were included. Blood examination and biochemical tests were evaluated. For cystic formation, renal ultrasound was performed. The PKD1 gene mutation was identified via polymerase chain reaction (PCR) and DNA sequencing. Matrix correlation and effectiveness of ultrasound for PKD1 mutation detection were determined. Results The results showed that 19.44% of cats had PKD1 mutations, a high prevalence in Persian and Persian-related breed cats. Our results demonstrated the characteristics of kidneys in wild-type cats and cats with gene mutations. Based on ultrasonography results, there was an association between cats with gene mutations and cyst formation. The findings indicated that ultrasound did not detect cysts in cats aged 4-36 months, supporting the evidence that PKD1 gene mutations may not be present. This study found high sensitivity and renal specificity ultrasound for PKD1 heterozygous mutation. Moreover, cystic formation via renal ultrasound showed an increased risk for PKD1 mutation 2,623 times compared to normal kidneys. Conclusions Ultrasonographic examination, coupled with genetic investigations, may help to clarify the phenotypic variability of PKD1. The phenotypic profile of PKD1 will guide therapeutic outcomes and reduce the prevalence of PKD morbidity and mortality in cats.

PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts.

Polycystic kidney disease (PKD) has a complex phenotype partly explained by genetic variants related to this disease. Ultrasonography is a promising approach for defining clinical signs. This study aimed to assess kidney characteristics in cats with Polycystin-1 (PKD1) gene mutations and wild-type cats. Kidney characteristics were identified by ultrasonography. A total of 108 cats of variable breeds aged an average of 37.01±3.50 months were included. Blood examination and biochemical tests were evaluated. For cystic formation, renal ultrasound was performed. The PKD1 gene mutation was identified via polymerase chain reaction (PCR) and DNA sequencing. Matrix correlation and effectiveness of ultrasound for PKD1 mutation detection were determined. The results showed that 19.44% of cats had PKD1 mutations, a high prevalence in Persian and Persian-related breed cats. Our results demonstrated the characteristics of kidneys in wild-type cats and cats with gene mutations. Based on ultrasonography results, there was an association between cats with gene mutations and cyst formation. The findings indicated that ultrasound did not detect cysts in cats aged 4-36 months, supporting the evidence that PKD1 gene mutations may not be present. This study found high sensitivity and renal specificity ultrasound for PKD1 heterozygous mutation. Moreover, cystic formation via renal ultrasound showed an increased risk for PKD1 mutation 2,623 times compared to normal kidneys. Ultrasonographic examination, coupled with genetic investigations, may help to clarify the phenotypic variability of PKD1. The phenotypic profile of PKD1 will guide therapeutic outcomes and reduce the prevalence of PKD morbidity and mortality in cats.

PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts

Background: Polycystic kidney disease (PKD) has a complex phenotype partly explained by genetic variants related to this disease. Ultrasonography is a promising approach for defining clinical signs. This study aimed to assess kidney characteristics in cats with Polycystin-1 (PKD1) gene mutations and wild-type cats. Kidney characteristics were identified by ultrasonography. Methods: A total of 108 cats of variable breeds aged an average of 37.01±3.50 months were included. Blood examination and biochemical tests were evaluated. For cystic formation, renal ultrasound was performed. The PKD1 gene mutation was identified via polymerase chain reaction (PCR) and DNA sequencing. Matrix correlation and effectiveness of ultrasound for PKD1 mutation detection were determined. Results: The results showed that 19.44% of cats had PKD1 mutations, a high prevalence in Persian and Persian-related breed cats. Our results demonstrated the characteristics of kidneys in wild-type cats and cats with gene mutations. Based on ultrasonography results, there was an association between cats with gene mutations and cyst formation. The findings indicated that ultrasound did not detect cysts in cats aged 4-36 months, supporting the evidence that PKD1 gene mutations may not be present. This study found high sensitivity and renal specificity ultrasound for PKD1 heterozygous mutation. Moreover, cystic formation via renal ultrasound showed an increased risk for PKD1 mutation 2,623 times compared to normal kidneys. Conclusions: Ultrasonographic examination, coupled with genetic investigations, may help to clarify the phenotypic variability of PKD1. The phenotypic profile of PKD1 will guide therapeutic outcomes and reduce the prevalence of PKD morbidity and mortality in cats.

Genetic analysis links the diagnosis of carriers of the PKD1 mutation gene that causes polycystic kidney disease

Polycystic kidney disease (PKD) is an inherited disorder characterised by the formation and growth of multiple cysts in the kidney, accompanied by a gradual increase in the size of both kidneys leading to impaired kidney function and renal failure. Autosomal dominant PKD is the most common genetic disorder with an estimated prevalence of 1/500-1/1000 in Western countries [1], caused by mutations in the PKD1 (MIM#601313) and PKD2 (MIM#173910), of which 85% of cases are caused by mutations in the PKD1 gene [2]. Because of the PKD1gene’s enormous size, numerous mutations, and up to 6 structural pseudogenes, which share a high degree of similarity sequences (97.7%) from the 5’UTR to exon 32 [3, 4], the methods for identifying PKD1 mutations are currently restricted and challenging from amplifying the mutant gene area. Therefore, it is essential to create a novel diagnostic technique with high accuracy and broad applicability for various mutation types that may circumvent the shortcomings of the conventional method. Objective: To develop a genetic linkage analysis technique for detecting the person with PKD1 mutation causing PKD. Materials and methods: 11 members were from a family with PKD1 gene mutations causing PKD. Designed PKD1 gene-linked STRs primers and conducted genetic linkage analysis with the family members. After comparing the outcomes of the technique with those of the Touchdown-PCR and ARMS-PCR methods, the complete technique is subsequently given. Results: Successfully developed the genetic linkage analysis technique for detecting the person with PKD1mutation causing PKD.

P221 ASSOCIATION BETWEEN AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE AND A SEVERE DILATED CARDIOMYOPATHY: A CASE REPORT

Abstract Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 and PKD2 genes, encoding polycystin 1 and 2. We report the case of a 51–year–old woman with arterial hypertension and stage V chronic kidney disease from polycystic kidney disease, without a significant family health history. She was admitted to our Cardiology Ward for worsening dyspnea, dependent oedemas and a 3/6 systolic heart murmur detected. Blood tests showed mild anemia and hyperkalemia, severe renal failure (creatinine 6 mg/dl) and normal both liver and thyroid function. The ECG showed sinus rhythm with normal atrioventricular conduction, low voltage in precordial leads and non–specific repolarization disturbances. Hemodialysis and intravenous decongestion therapy were started. A transthoracic two–dimensional echocardiography was performed and a dilated left ventricle with severe global systolic dysfunction (EF 25%) was documented, with severe secondary mitral regurgitation (MR) with a central jet (EROA 0,5 cm2). A possible bicuspid aortic valve was suggested with moderate aortic regurgitation. CT scans showed small pleural and pericardial effusions, polycystosis affecting both kidneys and liver. Coronary CT showed a subcritical interventricular artery stenosis and confirmed a bicuspid aortic valve. Magnetic resonance angiography was negative for intracranial aneurysms. Finally, genetic testing revealed a heterozygous pathogenic mutation of PKD1 gene (c.9622del G p.Ala3208Hisfs*108 exone 28). Maximum tolerated heart failure therapy was prescribed after discharge, resulting in symptoms reduction but only mild echocardiographic improvement (EF 30% with severe MR). An edge–to–edge transcatheter mitral valve repair was proposed. In literature we learn that PKD1 mutations are linked to various cardiomyopathies: hypertrophic, dilated, left ventricular non compaction. We report the association of ADPKD with a complex dilated cardiomyopathy with severe secondary MR, an aortic congenital defect and an associated subcritical coronary artery stenosis. Further investigations are needed to study the genetic aspect of the ADPKD when associated with different cardiac anomalies.

Modeling Pkd1 gene-targeted strategies for correction of polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) causes renal cysts and leads to end-stage renal disease in midlife due mainly to PKD1 gene mutations. Virtually no studies have explored gene therapeutic strategies for long-term effective treatment of PKD. Toward this aim, the severely cystic Pkd1-null mouse model was targeted with a series of transgene transfers using genomic Pkd1 under its regulatory elements (Pkd1wt), a kidney-targeted Pkd1 gene (SBPkd1), or Pkd1Minigene. The introduced Pkd1wt gene constructs with ∼8-fold overexpression display similar endogenous cellular profiles and full complementation of Pkd1-/- phenotype and establish the referral Pkd1 genomic length for proper regulation. SBPkd1 transgene transfer expressing 0.6- or 7-fold Pkd1 endogenous levels is sufficient to correct glomerular and proximal tubular cysts and to markedly postpone cysts in other tubular segments as well, showing that the small SB elements appreciably overlap with Pkd1 promoter/5' UTR regulation. Renal-targeted Pkd1Minigene at high copy numbers conveys an expression level similar to that of the endogenous Pkd1 gene, with widespread and homogeneous weak Pkd1 cellular signal, partially rescuing all cystic tubular segments. These transgene transfers determine that Pkd1 intragenic sequences regulate not only expression levels but also spatiotemporal patterns. Importantly, our study demonstrates that Pkd1 re-expression from hybrid therapeutic constructs can ameliorate, with considerably extended lifespan, or eliminate PKD.

Identification and Characterization of Novel Mutations in Chronic Kidney Disease (CKD) and Autosomal Dominant Polycystic Kidney Disease (ADPKD) in Saudi Subjects by Whole-Exome Sequencing.

Background: Autosomal dominant polycystic kidney disease (ADPKD) is a condition usually caused by a single gene mutation and manifested by both renal and extrarenal features, eventually leading to end-stage renal disease (ESRD) by the median age of 60 years worldwide. Approximately 89% of ADPKD patients had either PKD1 or PKD2 gene mutations. The majority (85%) of the mutations are in the PKD1 gene, especially in the context of family history. Objectives: This study investigated the genetic basis and the undiscovered genes that are involved in ADPKD development among the Saudi population. Materials and Methods: In this study, 11 patients with chronic kidney disease were enrolled. The diagnosis of ADPKD was based on history and diagnostic images: CT images include enlargement of renal outlines, renal echogenicity, and presence of multiple renal cysts with dilated collecting ducts, loss of corticomedullary differentiation, and changes in GFR and serum creatinine levels. Next-generation whole-exome sequencing was conducted using the Ion Torrent PGM platform. Results: Of the 11 Saudi patients diagnosed with chronic kidney disease (CKD) and ADPKD, the most common heterozygote nonsynonymous variant in the PKD1 gene was exon15: (c.4264G > A). Two missense mutations were identified with a PKD1 (c.1758A > C and c.9774T > G), and one patient had a PKD2 mutation (c.1445T > G). Three detected variants were novel, identified at PKD1 (c.1758A > C), PKD2L2 (c.1364A > T), and TSC2 (deletion of a'a at the 3'UTR, R1680C) genes. Other variants in PKD1L1 (c.3813_381 4delinsTG) and PKD1L2 (c.404C > T) were also detected. The median age of end-stage renal disease for ADPK patients in Saudi Arabia was 30 years. Conclusion: This study reported a common variant in the PKD1 gene in Saudi patients with typical ADPKD. We also reported (to our knowledge) for the first time two novel missense variants in PKD1 and PKD2L2 genes and one indel mutation at the 3'UTR of the TSC2 gene. This study establishes that the reported mutations in the affected genes resulted in ADPKD development in the Saudi population by a median age of 30. Nevertheless, future protein-protein interaction studies to investigate the influence of these mutations on PKD1 and PKD2 functions are required. Furthermore, large-scale population-based studies to verify these findings are recommended.

Cross talk between lysine methyltransferase Smyd2 and TGF-β-Smad3 signaling promotes renal fibrosis in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited genetic disorder that is caused by mutations in PKD1 or PKD2 genes and is characterized by renal fluid-filled cyst formation and interstitial fibrosis. PKD1 gene mutation results in the upregulation of SET (suppressor of variegation, enhancer of zeste, trithorax) and MYND (myeloid-nervy-DEAF1) domain-containing lysine methyltransferase 2 (SMYD2) in kidneys from Pkd1 mutant mice and patients with ADPKD. However, the role and mechanism of Smyd2 in the regulation of renal fibrosis in ADPKD remains elusive. In the present study, we showed that 1) expression of Smyd2 can be regulated by transforming growth factor (TGF)-β-Smad3 in normal rat kidney 49F (NRK-49F) cells and mouse fibroblast NIH3T3 cells; 2) knockdown of Smyd2 and inhibition of Smyd2 with its specific inhibitor, AZ505, decreases TGF-β-induced expression of α-smooth muscle actin, fibronectin, collagen type 1 and 3, and plasminogen activator inhibitor-1 in NRK-49F cells; 3) Smyd2 regulates the transcription of fibrotic marker genes through binding on the promoters of those genes or through methylating histone H3 to indirectly regulate the expression of those genes; and 4) knockout and inhibition of Smyd2 significantly decreases renal fibrosis in Pkd1 knockout mice, supporting that targeting Smyd2 can not only delay cyst growth but also attenuate renal fibrosis in ADPKD. This study identified a cross talk between TGF-β signaling and Smyd2 in the regulation of fibrotic gene transcription and activation of fibroblasts in cystic kidneys, suggesting that targeting Smyd2 with AZ505 is a potential therapeutic strategy for ADPKD treatment.NEW & NOTEWORTHY Here, we identified a cross talk between SET and MYND domain-containing lysine methyltransferase 2 (Smyd2) and transforming growth factor (TGF)-β-Smad3 signaling and a synergistic feedback loop between them, in which TGF-β stimulates expression of Smyd2 in a Smad3-dependent manner, and upregulation of Smyd2 regulates the transcription of TGF-β and other fibrotic marker genes through direct binding on their promoters or methylating histone H3 indirectly to regulate the transcription of those genes in fibroblasts. Thus, the Smyd2-TGF-β-Smad3-Smyd2 signaling axis plays an important role in promoting renal fibrosis, and targeting Smyd2 with its specific inhibitor should not only delay cyst growth but also ameliorate renal fibrosis in ADPKD.

Genetic diagnosis of ADPKD

Sequencing techniques represent the gold standard in molecular diagnosis ofautosomal dominant polycystic kidney disease (ADPKD), being in this case able to accurately and concretely highlight mutations at the genome level. The PKD1 gene mutation detection technique using the Real Time PCR technique and LNA hydrolysis probes exploits the specific behavior of hybridization LNA probes under the conditions of maximum complementarity with the target sequence and consequently the theoretical possibility of designing two such probes, one for the wild genotype (WT) and the other to identify the point mutation (MUT). The technique of identifying the PKD1 gene mutation using the Real Time PCR technique and FRET type hydrolysis probes consists of a derivation of the Real Time PCR technique, with the detection of amplicons by means of fluorescence with hybridization probes. The technique of identifying the PKD1 gene mutation using the Real Time PCR technique coupled with HRM (High Resolution Melting) involves one of the variants of the Real Time PCR technique, namely the interpretation of the results according to the melting temperature.

A Presumed Synonymous Mutation of PKD2 Caused Autosomal Dominant Polycystic Kidney Disease in a Chinese Family.

Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by the pathogenic mutation of PKD1 or PKD2 gene and usually affects bilateral kidneys. Synonymous mutations are generally assumed to be neutral as they do not alter amino acids. Herein, we described an extremely rare ADPKD child caused by a heterozygous synonymous mutation of PKD2 gene accompanied by massive proteinuria and congenital solitary kidney. Clinical characteristics of the patients were summarized. Whole-exome sequencing was performed to screen the disease-causing gene mutation, and reverse transcription polymerase chain reaction (RT-PCR) and Sanger sequencing were applied to analyze the impact of the identified mutation on gene transcription and splicing. Polycystic changes were found in the solitary kidney of a girl initially presented with nephrotic-range proteinuria. Thereafter her mother and 2 other family members were diagnosed to be ADPKD. Whole-exome sequencing of the proband identified a heterozygous synonymous mutation (c.1716G>A, p.Lys572=) located in the splicing site of exon 7 in PKD2 gene, which was co-segregated with the PKD phenotype in the family. RT-PCR and direct sequencing of amplified products revealed that this heterozygous synonymous mutation led to exon7 skipping in PKD2 gene. We reported an extremely rare child case of ADPKD2 in combination with solitary kidney and nephrotic-range proteinuria, and firstly confirmed the pathogenicity of a heterozygous synonymous mutation (c.1716G>A) in PKD2 gene. The results indicate that synonymous mutations should not be excluded from disease-causing if they are located in splicing site of an exon.

POS-433 MODELING PKD1 TARGETING STRATEGIES IN A PKD1 LOSS-OF-FUNCTION MOUSE MODEL

ADPKD is one of the most common inherited kidney diseases and cause of end stage renal disease. ADPKD is characterized by initiation and progression of multiple renal cysts. Most cases involve mutations in PKD1 gene, encoding Polycystin1(PC1). PKD1 gene dosage is supported as a pathogenic mechanism by studies in mouse models. Consistently, Pkd1 null mouse model develops severe renal cysts from e15.5 until neonatal death. With the aim of initiating studies for stable long-term effective correction of PKD, we propose a gene augmentation therapy as an appropriate strategy for reduced PC1 mutations that requires characterization of the minimal essential Pkd1 regulatory sequences/elements for proper renal developmental and temporal expression pattern.

Analysis of PKD1 and PKD2 Gene Mutations for Autosomal Dominant Polycystic Kidney Disease Cases in Turkish Population

Analysis of PKD1 and PKD2 Gene Mutations for Autosomal Dominant Polycystic Kidney Disease Cases in Turkish Population

Identification of missense and synonymous variants in Iranian patients suffering from autosomal dominant polycystic kidney disease

BackgroundAutosomal dominant polycystic kidney disease (ADPKD), the predominant type of inherited kidney disorder, occurs due to PKD1 and PKD2 gene mutations. ADPKD diagnosis is made primarily by kidney imaging. However, molecular genetic analysis is required to confirm the diagnosis. It is critical to perform a molecular genetic analysis when the imaging diagnosis is uncertain, particularly in simplex cases (i.e. a single occurrence in a family), in people with remarkably mild symptoms, or in individuals with atypical presentations. The main aim of this study is to determine the frequency of PKD1 gene mutations in Iranian patients with ADPKD diagnosis.MethodsGenomic DNA was extracted from blood samples from 22 ADPKD patients, who were referred to the Qaem Hospital in Mashhad, Iran. By using appropriate primers, 16 end exons of PKD1 gene that are regional hotspots, were replicated with PCR. Then, PCR products were subjected to DNA directional Sanger sequencing.ResultsThe DNA sequencing in the patients has shown that exons 35, 36 and 37 were non- polymorphic, and that most mutations had occurred in exons 44 and 45. In two patients, an exon-intron boundary mutation had occurred in intron 44. Most of the variants were missense and synonymous types.ConclusionIn the present study, we have shown the occurrence of nine novel missense or synonymous variants in PKD1 gene. These data could contribute to an improved diagnostic and genetic counseling in clinical settings.

Isolated hypoglossal nerve palsy from internal carotid artery dissection related to PKD-1 gene mutation

BackgroundInternal carotid artery dissection has been well recognized as a major cause of ischaemic stroke in young and middle-aged adults. However, internal carotid artery dissection induced hypoglossal nerve palsy has been seldom reported and may be difficult to diagnose in time for treatment; even angiography sometimes misses potential dissection, especially when obvious lumen geometry changing is absent.Case presentationWe report a 42-year-old man who presented with isolated hypoglossal nerve palsy. High-resolution MRI showed the aetiological dissected internal carotid artery. In addition, a potential genetic structural defect of the arterial wall was suggested due to an exon region mutation in the polycystic-kidney-disease type 1 gene.ConclusionsHypoglossal nerve palsy is a rare manifestations of carotid dissection. High-resolution MRI may provide useful information about the vascular wall to assist in the diagnosis of dissection. High-throughput sequencing might be useful to identify potential cerebrovascular-related gene mutation, especially in young individuals with an undetermined aetiology.

Renal hypertrophic signaling triggers activation of kidney immune response and accelerates cystogenesis in polycystic kidney disease

BackgroundAutosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease with the predominant form resulting from mutations in the gene, PKD1. The disease severity is highly variable even among families with the same PKD1 gene mutation and factors other than genetics may affect cystogenesis. Protein load or unilateral nephrectomy (UNx: 1K) results in glomerular hyperfiltration and renal hypertrophy which both accelerates kidney cyst growth in PKD mice. Children with PKD that exhibit glomerular hyperfiltration were shown to have a higher rate of cyst growth and faster decline in kidney function. Thus, hypertrophic signaling in PKD may clinically be a risk factor to accelerate cystogenesis.MethodsTo test the effect of renal hypertrophy in PKD, we used adult tamoxifen inducible Pkd1flox/flox mice with or without CAGG‐cre. Three weeks after cre induction, first group of mice underwent sham surgery or UNx to accelerate cyst formation and observed for 3 or 6 weeks. The second group of mice were fed with either high protein (60%), normal protein (18%) or low protein diet (6%) for a total of 6 weeks. Mice from both UNx and modified protein diet group were sacrificed at the end of the experiment and kidneys were harvested for RNA‐seq, histology, inflammatory cytokines and flow cytometry for kidney immune cell sorting.ResultsAnalysis of RNA sequencing data revealed that 1K compared to intact two kidney (2K) Pkd1 deficient mice show differentially expressed genes involved in activating/recruiting macrophages and production of pro‐inflammatory cytokines during the hypertrophic signaling. 1K compared to 2K Pkd1 mice had increased number of resident macrophage (CD11blo, F4/80 hi) but not infiltrating macrophages (CD11bhi, F4/80lo), increased inflammatory cytokine production, and severe cystic kidneys. Pkd1 deficient mice that were given a high protein diet compared to a low protein diet, resulted in activation of kidney immune cells, recruitment of inflammatory cytokines and worsening kidney cysts.ConclusionsRenal hypertrophic signaling triggered by either UNx or protein load in adult Pkd1 mice activates kidney immune cells, inflammatory cytokine production and accelerates cyst growth.Support or Funding InformationNIH K08DK106465, P30 DK074038, T32AI007051This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Study of two pedigrees affected with adult polycystic kidney disease and male infertility resulting from novel mutations of PKD1

To explore the genetic etiology of two Chinese pedigrees affected with autosomal dominant adult polycystic kidney disease and male infertility. The coding regions of the PKD1 and PKD2 genes were subjected to PCR and Sanger sequencing. Suspected pathogenic mutations were analyzed by pedigree analysis and bioinformatics analysis. Mutation screening was performed using Sanger sequencing of blood samples obtained from 50 healthy individuals. Two novel heterozygous mutations, c.6953_6977 del(p.Arg2318Hisfs*15) and c.10937T>G (p.Val3646Gly) of the PKD1 gene were identified in the affected members of the two pedigrees, respectively, but not among to normal family members of the two pedigrees. Pedigree and bioinformatics analysis showed that both mutations were pathogenic. No pathological mutations were found in the cohort of 50 healthy individuals. Two novel mutations, c.6953_6977del(p.Arg2318Hisfs*15) and c.10937T>G (p.Val3646Gly) of the PKD1 gene may be responsible for the disease in the two pedigrees, which have enriched the spectrum of PKD1 gene mutations and provided a basis for genetic counseling and prenatal disgnosis.

Comparison analysis of Baso Cellular Carcinoma and Spino Cellular Carcinoma - Protein Kinase D1, Wnt/β-catenin and Epithelial to Mesenchimal Transition (markers)

Understanding cancer biology is crucial to the successful diagnosis and application of personalized therapies. Skin carcinogenesis is a multi-step process. The first step is the development of potentially malignant disorders (PMDs) known as leukoplakia, erytroplakia, lichen planus, probably trough mutation in the proteins regulated cell cycle (p16INK4A, p21Waf1/Cip1/Sdi1, p27 kip1, Cyclin D1) and, second in p53 (TP53), Ras, hTert, EGFR, will reverse benign phenotype of late precancer lesions (PMDs) into benign cancer lesion. Third mutation probably in PI3K, PKD1 or E-cadherin, will increase malignant potential of SCCs, activating EMTransition, invasion and metastasis, e.g. aggressive phenotype. In BCC mutations of p53 are known to be late events (UV signature), whereas silencing of 14-3-3 takes place early in tumor progression, concomitant with increased activity of Snail. Early increased expression of PKD1 and down-regulation of c-myc mRNA are also events in pathogenesis of BCC. There is no data for detected mutations in PKD1 gene in both cancers, although the kinases is with high expression in BCC and lack of expression in SCC. There is no data concerning PKD1 expression in the PMDs leading to SCCs, nor to BCCs, such data were recently published concerning PKD1 expression in pancreatic oncogenesis. Curently adequate question is whether lack of PKD1 expression in SCCs, despite its PMDs origin, is a consequence of its spinous layer origin, or is a consequense of PKD1 gene mutations (downregulation). Identification of mutations as markers for early malignant transformation could be useful for early diagnosis and treatment of skin head and neck cancers.