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1.
J Hum Genet ; 68(10): 671-680, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37217688

RESUMO

Cystic fibrosis (CF) is an autosomal recessive disease caused by pathogenic variants in CF transmembrane conductance regulator (CFTR). While CF is the most common hereditary disease in Caucasians, it is rare in East Asia. In the present study, we have examined clinical features and the spectrum of CFTR variants of CF patients in Japan. Clinical data of 132 CF patients were obtained from the national epidemiological survey since 1994 and CF registry. From 2007 to 2022, 46 patients with definite CF were analyzed for CFTR variants. All exons, their boundaries, and part of promoter region of CFTR were sequenced and the presence of large deletion and duplications were examined by multiplex ligation-dependent probe amplification. CF patients in Japan were found to have chronic sinopulmonary disease (85.6%), exocrine pancreatic insufficiency (66.7%), meconium ileus (35.6%), electrolyte imbalance (21.2%), CF-associated liver disease (14.4%), and CF-related diabetes (6.1%). The median survival age was 25.0 years. The mean BMI percentile was 30.3%ile in definite CF patients aged < 18 years whose CFTR genotypes were known. In 70 CF alleles of East Asia/Japan origin, CFTR-dele16-17a-17b was detected in 24 alleles, the other variants were novel or very rare, and no pathogenic variants were detected in 8 alleles. In 22 CF alleles of Europe origin, F508del was detected in 11 alleles. In summary, clinical phenotype of Japanese CF patients is similar to European patients, but the prognosis is worse. The spectrum of CFTR variants in Japanese CF alleles is entirely different from that in European CF alleles.


Assuntos
Fibrose Cística , Humanos , Fibrose Cística/epidemiologia , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Mutação , Japão/epidemiologia , Genótipo
2.
Nihon Shokakibyo Gakkai Zasshi ; 118(7): 686-697, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34248082

RESUMO

A 9-year-old Japanese girl was found to have persistently elevated hepatic enzymes, chronic bronchitis, chronic sinusitis, and poor weight gain beginning at 5 months of age. Chest computed tomography (CT) revealed diffuse bronchial wall thickening and peripheral bronchiectasis. Abdominal CT showed pancreatic atrophy, liver cirrhosis, a dilated splenic vein, and splenomegaly. Her sweat chloride concentration was 117mmol/l (normal, <60mmol/l). CFTR gene analysis revealed the presence of the Y517H variant on one allele and the 1540del10 variant one the other allele. These findings established a definitive diagnosis of cystic fibrosis (CF). While CF is the most common autosomal recessive genetic disorder among Europeans, it is quite rare in Southeast Asia including Japan. It is important that CF be considered in the work-up of children with chronic hepatic and respiratory disorders even if it is uncommon among children of a similar background.


Assuntos
Fibrose Cística , Hipertensão Portal , Cirrose Hepática Biliar , Criança , Fibrose Cística/complicações , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Feminino , Humanos , Hipertensão Portal/etiologia , Japão , Mutação
3.
Front Pediatr ; 9: 800095, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35047466

RESUMO

Cystic fibrosis (CF) is a rare disease in the Japanese. The most common CFTR variant in Japanese CF patients is a large heterozygous deletion that can easily avoid detection by standard gene sequencing methods. We herein report a novel large heterozygous deletion in the CFTR gene in Japanese siblings with CF. A genetic analysis was performed in two patients (9-year-old boy and 5-month-old girl) who were clinically diagnosed with CF because of the positive result for the rapid fecal pancreatic elastase antigen test and the elevation of the sweat chloride concentration. In addition to conventional polymerase chain reaction (PCR) and direct sequencing, multiplex ligation-dependent probe amplification (MLPA) was performed to check for a large deletion and duplication of the CFTR gene. Based on MLPA findings, the breakpoint of heterozygous deletion was identified by real-time quantitative PCR followed by the sequence of the amplified junction fragment. In MLPA, the numbers of the fragments corresponding to exons 1, 16, 17a, and 17b and 234 nt and 747 nt upstream from the translation initiation codon of exon 1 in the CFTR gene and exon 3 in the ASZ1 gene were reduced by almost half. The c.2908+1085_3367+260del7201 variant (exon 16-17b deletion) was identified in one allele. The other allele had a large 137,567-bp deletion from g.117,361,112 (ASZ1 3' flanking region) to g.117,498,678 (CFTR intron 1) on chromosome 7. Since the deletion variant lacked the entire promoter region of CFTR, CFTR mRNA would not be transcribed from the allele, indicating it to be a novel pathogenic variant causing CF. As large mutations are frequently detected in Japanese CF patients, MPLA can be useful when searching for variants.

4.
Am J Physiol Gastrointest Liver Physiol ; 309(4): G260-9, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26089335

RESUMO

Although cystic fibrosis is rare in Japanese, measurement of sweat Cl(-) has suggested mild dysfunction of cystic fibrosis transmembrane conductance regulator (CFTR) in some patients with chronic pancreatitis. In the present study, we have investigated the association of CFTR variants and chronic pancreatitis in Japanese and the functional characteristics of a Japanese- and pancreatitis-specific CFTR variant, L1156F. Seventy patients with alcoholic chronic pancreatitis, 18 patients with idiopathic chronic pancreatitis, and 180 normal subjects participated. All exons and their boundaries and promoter region of the CFTR gene were sequenced. Human embryonic kidney-293 cells were transfected with three CFTR variants (M470V, L1156F, and M470V+L1156F), and the protein expression was examined. Xenopus laevis oocytes were injected with the CFTR variants, and bicarbonate (HCO3 (-)) transport activity was examined. CFPAC-1 cells were transfected with the CFTR variants and Cl(-)/HCO3 (-) exchange activity was examined. Six variants (E217G, I556V, M470V, L1156F, Q1352H, and R1453W) were identified in the coding region of the CFTR gene. Cystic fibrosis-causing mutations were not found. The allele frequencies of L1156F and Q1352H in alcoholic chronic pancreatitis (5.0 and 7.9%) were significantly (P < 0.01) higher than those in normal subjects (0.6 and 1.9%). L1156F was linked with a worldwide CFTR variant, M470V. Combination of M470V and L1156F significantly reduced CFTR expression to ∼60%, impaired CFTR-mediated HCO3 (-)/Cl(-) transport activity to 50-60%, and impaired CFTR-coupled Cl(-)/HCO3 (-) exchange activity to 20-30%. The data suggest that the Japanese-specific CFTR variant L1156F causes mild dysfunction of CFTR and increases the risk of alcoholic chronic pancreatitis in Japanese.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Mutação de Sentido Incorreto , Pancreatite Alcoólica/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bicarbonatos/metabolismo , Estudos de Casos e Controles , Cloretos/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Éxons , Feminino , Frequência do Gene , Células HEK293 , Humanos , Transporte de Íons , Japão , Masculino , Pessoa de Meia-Idade , Xenopus
5.
Nagoya J Med Sci ; 74(3-4): 293-301, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23092102

RESUMO

BACKGROUND AND AIM: Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a chloride channel, cause cystic fibrosis. In order to investigate the polymorphic backgrounds of CFTR genes of healthy populations in different Chinese cities (Changchun and Nanjing), we analyzed 119 blood samples (Changchun 64, Nanjing 55) of randomly selected healthy individuals for poly T, TG-repeats and M470V polymorphisms. We analyzed the differences of CFTR polymorphic distributions between the two Chinese cities from the south and the north. Methods Genomic DNA was extracted from whole blood. DNA fragments of CFTR gene were amplified by polymerase chain reaction (PCR). Poly-T and TG repeats were directly sequenced by auto sequencer (ABI 310). M470V was detected by a HphI restriction enzyme. RESULTS: The T7 allele was the most common haplotype in Changchun (0.938) and Nanjing (0.927) populations. The T5 allele was present in only 7 Changchun and 3 Nanjing subjects. The TG11 and TG12 alleles were dominant haplotypes in Changchun (TG11 0.500, TG12 0.453) and Nanjing (TG11 0.345, TG12 0.609). The frequency of the V470 allele was 0.633 in Changchun, which was higher than that in Nanjing (0.500) (p < 0.05). There were three major haplotypes: T7-TG11-V470, T7-TG12-M470 and T7-TG12-V470. The T7-TG11-V470 was the most common haplotype in Changchun (0.514), while T7-TG12-M470 was the most common haplotype in Nanjing (0.500). CONCLUSION: Though Changchun and Nanjing are in the same country, their polymorphic backgrounds of CFTR gene are very different. Most of the two populations have genotypes that cause lower CFTR function.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Polimorfismo Genético/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , Criança , Cidades , Feminino , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Pancreas ; 41(8): 1292-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22647734

RESUMO

OBJECTIVES: Mutation in the Pkhd1 gene that encodes a ciliary protein, fibrocystin, causes multiple cysts in the kidneys and liver in the polycystic kidney (PCK) rat, a model for human autosomal recessive PCK disease. To clarify the role of primary cilia in the pancreatic duct, we examined the structure and function of the exocrine pancreas of PCK rats. METHODS: Pancreatic juice and bile were collected from anesthetized rats. Pancreatic ductal structure was analyzed by microdissection and immunohist0chemistry. RESULTS: Histologically pancreatic acini were apparently normal, and no cysts were detected in the pancreas. Larger pancreatic ducts were irregularly dilated with enhanced expression of AQP1 in epithelial cells. The pancreatic duct of PCK rats exhibited significantly (P < 0.05) higher distensibility than that of wild-type (WT) rat at a physiological luminal pressure (3 cm H2O). Pancreatic fluid secretion stimulated with a physiological dose of secretin (0.03 nmol/kg per hour) in PCK rats was significantly smaller than that in WT, but the differences were not significant at higher doses. The amylase responses to carbamylcholine were not different between PCK and WT rats. CONCLUSIONS: These findings suggest that fibrocystin/primary cilia-dependent mechanisms may play a role in the regulation of pancreatic ductal structure and fluid secretion.


Assuntos
Pâncreas Exócrino/fisiopatologia , Doenças Renais Policísticas/patologia , Amilases/metabolismo , Animais , Aquaporina 1/biossíntese , Bile/efeitos dos fármacos , Carbacol/administração & dosagem , Agonistas Colinérgicos/administração & dosagem , Modelos Animais de Doenças , Humanos , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Mutação , Pâncreas Exócrino/efeitos dos fármacos , Pâncreas Exócrino/patologia , Ductos Pancreáticos/patologia , Ductos Pancreáticos/fisiopatologia , Suco Pancreático/efeitos dos fármacos , Suco Pancreático/fisiologia , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Superfície Celular/genética , Secretina/administração & dosagem
7.
J Hum Genet ; 57(7): 427-33, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22572733

RESUMO

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in CFTR (CF transmembrane conductance regulator). Although CF is the most common hereditary disease in Caucasians, it is rare in Asian populations. Common disease-causing mutations of CFTR in Caucasians are rarely identified in Japanese patients with CF. In the present study, CFTR transcripts from nasal swab were analyzed in a Japanese boy, in addition to conventional PCR and direct sequence of all exons, their boundaries and promoter region of the CFTR gene. The boy was diagnosed with CF by chronic respiratory infection and the elevated sweat chloride level. None of the disease-causing mutations of CFTR was detected by the conventional analysis. Cloning and sequence of the CFTR transcripts revealed a heterozygous deletion spanning exons 16, 17a and 17b. The deletion was confirmed by multiplex ligation-dependent probe amplification and the direct sequence of the junction fragment obtained from the genomic DNA by primer walking, which revealed the mutation c.2908+1085_3367+260del7201. We also identified a splicing defect: deletion/skipping of exon 1 in the CFTR transcript from the other allele. The analysis of CFTR transcripts from nasal swab is recommended in the genetic analysis of CF in Japanese.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Fibrose Cística/genética , Heterozigoto , Splicing de RNA , Deleção de Sequência , Alelos , Povo Asiático , Sequência de Bases , Cloretos/análise , Cloretos/metabolismo , Clonagem Molecular , Fibrose Cística/diagnóstico , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Éxons , Testes Genéticos/métodos , Humanos , Lactente , Masculino , Mucosa Nasal/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Suor/metabolismo
8.
J Biomed Res ; 26(6): 410-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23554779

RESUMO

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene have been implicated in the onset of cystic fibrosis and other clinical respiratory disorders. In the present study, we investigated the role of CFTR variations, poly-T, TG-repeats, and M470V in susceptibility to bronchial asthma and chronic bronchitis in a Chinese population in Jiangsu province, China. A total of 72 bronchial asthma patients, 68 chronic bronchitis patients, and 117 healthy subjects were included in this study. The Tn-TGm haplotype was sequenced and the CFTR variant M470V was detected using restriction fragment length polymorphism (RFLP). We found that the frequency of T5-TG12-V470 in chronic bronchitis patients was 0.07%, which was notably higher than that in healthy subjects (0.01%) and bronchial asthma patients (0.04%). Thus, the presence of the T5-TG12 haplotype of the CFTR gene is likely to play a role in the development and progression of respiratory conditions, such as chronic bronchitis.

9.
World J Gastroenterol ; 16(38): 4865-70, 2010 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-20939117

RESUMO

AIM: To determine the effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on left gastric artery (LGA) flow and to unveil the structural or functional important sites that may be critical for discrimination of different receptor subtypes. METHODS: Peptides, including PACAP-27, PACAP-38, amino acid substituted PACAP-27 and C-terminus truncated analogues PACAP (27-38), were synthesized by a simultaneous multiple solid-phase peptide synthesizer. Flow probes of an ultrasound transit-time blood flowmeter were placed around the LGA of beagle dogs. When peptides were infused intravenously, the blood flow was measured. RESULTS: [Ala4, Val5]-PACAP-27 caused a concentration-dependent vasodepressor action which was similar to that caused by PACAP-27. The LGA blood flow response to [Ala4, Val5]-PACAP-27 was significantly higher than that to PACAP-27, which was similar to that to vasoactive intestinal polypeptide (VIP) at the same dose. [Ala6]-PACAP-27 did not increase the peak LGA flow. [Gly8]-PACAP-27 showed a similar activity to VIP. [Asn24, Ser25, Ile26]-PACAP-27 did not change the activity of peptides at all doses. CONCLUSION: NH2 terminus is more important to biological activity of peptides and specific receptor recognition than COOH-terminus.


Assuntos
Artérias/efeitos dos fármacos , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Estômago/irrigação sanguínea , Sequência de Aminoácidos , Animais , Cães , Hemodinâmica/efeitos dos fármacos , Dados de Sequência Molecular , Peptídeos/síntese química , Peptídeos/genética , Peptídeos/farmacologia , Peptídeo Intestinal Vasoativo/genética , Peptídeo Intestinal Vasoativo/farmacologia
11.
J Gastroenterol ; 45(6): 584-91, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20422433

RESUMO

In Japan, we are now using the clinical diagnostic criteria for chronic pancreatitis (CP) that were revised in 2001 to add the findings of magnetic resonance cholangiopancreatography to the criteria compiled by the Japan Pancreas Society (JPS) in 1995. Because the current criteria are set for diagnosing advanced CP, they are unlikely to improve patients' prognoses. In addition, they seem unsuitable for current clinical practice because exocrine pancreatic function tests, which have become obsolete in Japan, are included in the diagnostic factors. For these reasons, the Research Committee on Intractable Pancreatic Diseases supported by the Ministry of Health, Labour and Welfare of Japan, the JPS and the Japanese Society of Gastroenterology have revised the criteria. The revised criteria are unique in that they contain an introduction to the concept of early CP. It is a challenge aimed at improvement of the long-term prognosis of CP patients by early diagnosis and therapeutic intervention in this disease. We need to determine and clarify the clinico-pathological outcome of early CP by a prospective long-term follow-up of the patients in this category.


Assuntos
Colangiopancreatografia por Ressonância Magnética/métodos , Pancreatite Crônica/diagnóstico , Diagnóstico Precoce , Humanos , Japão , Testes de Função Pancreática/métodos , Pancreatite Crônica/patologia , Prognóstico , Sociedades Médicas , Fatores de Tempo
12.
Gastroenterology ; 138(5): 1988-96, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20080093

RESUMO

BACKGROUND & AIMS: Corticosteroids are now widely accepted as a treatment for autoimmune pancreatitis (AIP). However, the molecular mechanism by which steroid treatment improves AIP remains largely unknown. The aim of this study was to elucidate cellular mechanisms by which corticosteroids improve both pancreatic exocrine function and histopathology in AIP. METHODS: Pancreatic exocrine function was evaluated by the secretin-stimulated function test and pancreatic biopsy specimens were processed for histologic analysis at the time of diagnosis and 3 months after initiation of steroid treatment. Expression and localization of proteins was assayed by immunohistochemistry. Analysis of immunoglobulin (Ig)G4-positive plasma cells was used to verify inflammation in AIP. RESULTS: The number of IgG4-positive plasma cells in pancreatic sections was decreased by steroid treatment, indicating reduced inflammation. Fluid, bicarbonate (HCO(3)(-)), and digestive enzyme secretions all were impaired in most patients with AIP. Corticosteroids improved both HCO(3)(-) and digestive enzyme secretion. A large fraction of the cystic fibrosis transmembrane conductance regulator (CFTR), which plays a central role in pancreatic duct HCO(3)(-) secretion, was mislocalized to the cytoplasm of duct cells before treatment. Corticosteroids corrected the localization of CFTR to the apical membrane, accounting for the improved HCO(3)(-) secretion. Steroid treatment resulted in regeneration of acinar cells, accounting for restored digestive enzyme secretion. CONCLUSIONS: Corticosteroids reduce inflammation and restore both digestive enzyme and HCO(3)(-) secretion in patients with AIP by regenerating acinar cells and correcting CFTR localization in pancreatic duct cells. Mislocalization of CFTR may explain aberrant HCO(3)(-) secretion in other forms of pancreatitis.


Assuntos
Corticosteroides/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Pâncreas Exócrino/efeitos dos fármacos , Ductos Pancreáticos/efeitos dos fármacos , Pancreatite/tratamento farmacológico , Regeneração/efeitos dos fármacos , Antígeno AC133 , Adulto , Idoso , Antígenos CD/metabolismo , Aquaporina 1/metabolismo , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Bicarbonatos/metabolismo , Feminino , Fibrose , Glicoproteínas/metabolismo , Humanos , Imunoglobulina G/metabolismo , Masculino , Pessoa de Meia-Idade , Pâncreas Exócrino/imunologia , Pâncreas Exócrino/metabolismo , Ductos Pancreáticos/imunologia , Ductos Pancreáticos/metabolismo , Suco Pancreático/enzimologia , Pancreatite/imunologia , Pancreatite/metabolismo , Peptídeos/metabolismo , Plasmócitos/efeitos dos fármacos , Plasmócitos/imunologia , Transporte Proteico , Fatores de Tempo , Resultado do Tratamento
13.
Alcohol Clin Exp Res ; 34 Suppl 1: S34-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18986377

RESUMO

BACKGROUND: Excessive consumption of alcohol is involved in the onset of pancreatitis. However, most of heavy drinkers do not always develop chronic pancreatitis. Various genetic factors appear to be involved in these individual differences in onset of chronic alcoholic pancreatitis. Here we investigated a possible association of alcoholic pancreatitis with polymorphisms of the various genes belong to the phase II detoxification enzymes responsible for metabolism of the oxidative compounds, and the several genes that have relevance to inherited pancreatitis. METHODS: The subjects consisted of 53 patients with chronic alcoholic pancreatitis, 54 alcoholic patients without pancreatic dysfunction, and 42 healthy individuals. DNA was extracted from the peripheral nucleated blood cells of all subjects and genetic mutations and subtypes were analyzed by the PCR and RFLP methods. We examined the correlation between chronic alcoholic pancreatitis and variants of the phase II detoxification enzymes such as Glutathione S-transferase M1 (GSTM1), glutathione S-transferase theta 1 (GSTT1), NADPH-quinone oxidoreductase 1 (NQO1), and N-acetyl transferase (NAT2). In addition, genes of lipoprotein lipase (LPL), cationic trypsinogen (PRSS1), pancreatic secretory trypsin inhibitor (PSTI), and cystic fibrosis transmembrane conductance regulator (CFTR) were also analyzed. RESULTS: Frequencies of the gene deletion of GSTM1 and GSTT1 in addition to the C-allele frequency of NQO1 tended to be higher in the alcoholic patients with (AlCP) or without pancreatic dysfunction (Alc) than in the healthy controls although the difference was not significant. The NAT2 gene showed no relation with Alc and AlCP patients. PSTI, LPL, PRSS1, and CFTR genes presented no association with chronic alcoholic pancreatitis. CONCLUSIONS: All genes analyzed in the present study lacked association with chronic alcoholic pancreatitis. However, the gene deletion of GSTM1 and GSTT1, and the C-allele of NQO1 cannot be ruled out for association with alcoholism.


Assuntos
Pancreatite Alcoólica/genética , Polimorfismo Genético/genética , Adulto , Idoso , Arilamina N-Acetiltransferase/genética , Proteínas de Transporte/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Deleção de Genes , Frequência do Gene , Genótipo , Glutationa Transferase/genética , Humanos , Lipase Lipoproteica/genética , Pessoa de Meia-Idade , NAD(P)H Desidrogenase (Quinona)/genética , Tripsina/genética , Inibidor da Tripsina Pancreática de Kazal
14.
Pflugers Arch ; 459(1): 215-26, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19756716

RESUMO

Cellular mechanisms underlying the impairment of pancreatic fluid and electrolyte secretion in diabetes were examined using interlobular ducts isolated from rat pancreas. Fluid secretion was assessed by monitoring changes in luminal volume. HCO3(-) uptake across the basolateral membrane was estimated from the recovery of intracellular pH following an acid load. Exposure to high glucose concentrations inhibited fluid secretion and reduced the rate of basolateral HCO3(-) uptake in secretin-stimulated ducts isolated from normal rats. In ducts isolated from streptozotocin-treated diabetic rats, fluid secretion and basolateral HCO3(-) uptake were also severely impaired but could be largely reversed by incubation in normal-glucose solutions. Sodium-dependent glucose cotransporter 1 (SGLT1), glucose transporter (GLUT)1, GLUT2, and GLUT8 transcripts were detected by reverse transcriptase polymerase chain reaction in isolated ducts. Raising the luminal glucose concentration in microperfused ducts caused a depolarization of the membrane potential, consistent with the presence of SGLT1 at the apical membrane. Unstimulated ducts filled with high-glucose solutions lost luminal fluid by a phlorizin-sensitive mechanism, indicating that pancreatic ducts are capable of active glucose reabsorption from the lumen via SGLT1. In ducts exposed to high glucose concentrations, continuous glucose diffusion to the lumen and active reabsorption via SGLT1 would lead to elevation of intracellular Na+ concentration and sustained depolarization of the apical membrane. These two factors would tend to inhibit the basolateral uptake and apical efflux of Cl(-) and HCO3(-) and could therefore account for the impaired fluid and electrolyte secretion that is observed in diabetes.


Assuntos
Bicarbonatos/metabolismo , Diabetes Mellitus Experimental/metabolismo , Glucose/metabolismo , Ductos Pancreáticos/metabolismo , Animais , Diabetes Mellitus Experimental/fisiopatologia , Glucose/farmacologia , Masculino , Potenciais da Membrana , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Secretina/metabolismo , Secretina/farmacologia , Transportador 1 de Glucose-Sódio/metabolismo
15.
J Gen Physiol ; 133(3): 315-26, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19204187

RESUMO

Pancreatic duct epithelium secretes a HCO(3)(-)-rich fluid by a mechanism dependent on cystic fibrosis transmembrane conductance regulator (CFTR) in the apical membrane. However, the exact role of CFTR remains unclear. One possibility is that the HCO(3)(-) permeability of CFTR provides a pathway for apical HCO(3)(-) efflux during maximal secretion. We have therefore attempted to measure electrodiffusive fluxes of HCO(3)(-) induced by changes in membrane potential across the apical membrane of interlobular ducts isolated from the guinea pig pancreas. This was done by recording the changes in intracellular pH (pH(i)) that occurred in luminally perfused ducts when membrane potential was altered by manipulation of bath K(+) concentration. Apical HCO(3)(-) fluxes activated by cyclic AMP were independent of Cl(-) and luminal Na(+), and substantially inhibited by the CFTR blocker, CFTR(inh)-172. Furthermore, comparable HCO(3)(-) fluxes observed in ducts isolated from wild-type mice were absent in ducts from cystic fibrosis (Delta F) mice. To estimate the HCO(3)(-) permeability of the apical membrane under physiological conditions, guinea pig ducts were luminally perfused with a solution containing 125 mM HCO(3)(-) and 24 mM Cl(-) in the presence of 5% CO(2). From the changes in pH(i), membrane potential, and buffering capacity, the flux and electrochemical gradient of HCO(3)(-) across the apical membrane were determined and used to calculate the HCO(3)(-) permeability. Our estimate of approximately 0.1 microm sec(-1) for the apical HCO(3)(-) permeability of guinea pig duct cells under these conditions is close to the value required to account for observed rates of HCO(3)(-) secretion. This suggests that CFTR functions as a HCO(3)(-) channel in pancreatic duct cells, and that it provides a significant pathway for HCO(3)(-) transport across the apical membrane.


Assuntos
Proteínas de Transporte de Ânions/metabolismo , Bicarbonatos/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Ductos Pancreáticos/citologia , Animais , Transporte Biológico/fisiologia , Membrana Celular/metabolismo , Cloretos/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/química , Feminino , Cobaias , Camundongos , Camundongos Endogâmicos CFTR , Ductos Pancreáticos/metabolismo , Permeabilidade , Sódio/metabolismo
16.
J Med Invest ; 56 Suppl: 308-11, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20224212

RESUMO

Pancreatic duct cells express Na(+)-dependent glucose transporter, SGLT1 and Na(+)-independent glucose transporters, GLUT1, GLUT2, and GLUT8. We examined transepithelial glucose transport by pancreatic duct. Interlobular ducts were isolated from rat pancreas. During overnight culture both ends of the duct segments sealed spontaneously. The lumen of the sealed duct was micropunctured and the luminal fluid was replaced by HEPES-buffered solution containing 10.0 mM or 44.4 mM glucose. The bath was perfused with HEPES-buffered solution at 37 degrees C containing 10.0 or 44.4 mM glucose. Transepithelial differences in osmolality were balanced with mannitol. Glucose transport across ductal epithelium was measured by monitoring changes in luminal volume. When the lumen was filled with 44.4 mM glucose, with either 10.0 or 44.4 mM glucose in the bath, the luminal volume decreased to 65 approximately 70% of the initial volume in 15 min. Luminally-injected phlorizin, an inhibitor of SGLT1, abolished the decrease in luminal volume. With 10.0 mM glucose in the lumen and 44.4 mM glucose in the bath, the luminal volume did not change significantly. Luminal application of phlorizin under identical condition led to an increase in luminal volume. The data suggest that both active and passive transport mechanisms of glucose are present in pancreatic ductal epithelium.


Assuntos
Células Epiteliais/metabolismo , Glucose/metabolismo , Pâncreas/citologia , Pâncreas/metabolismo , Animais , Transporte Biológico/fisiologia , Diabetes Mellitus Experimental/metabolismo , Glucose/farmacocinética , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 2/metabolismo , Modelos Animais , Ratos , Transportador 1 de Glucose-Sódio/metabolismo , Estreptozocina
17.
J Med Invest ; 56 Suppl: 318-21, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20224214

RESUMO

Chronic pancreatitis with all kinds of etiologies is characterized by pancreatic exocrine dysfunction especially impaired fluid secretion from pancreatic ducts. However, the molecular mechanism of this impaired fluid secretion in chronic pancreatitis is largely unknown. Aquaporin water channels are intrinsic membrane proteins expressed most of the cell types which have high osmotic water permeability. Among them aquaporin 1 (AQP1) is a predominant water channel expressed in the plasma membranes of human pancreatic ducts. Exocrine function test revealed that fluid secretion was severely impaired in AIP. immunohistochemical analysis revealed that AQP1 is localized mainly in the apical and lateral membranes of small pancreatic ducts in control subjects. AQP1 expression was significantly increased in plasma membranes of pancreatic ducts in AIP. Upregulation of AQP1 expression seen in pancreatic ducts of patient with AIP may be caused by the reduced fluid secretion from the pancreas as compensation. Further study would be required to elucidate the precise molecular mechanism for the role of AQP1 in pancreatic fluid secretion from the pancreas in diseases characterized by the impaired ductal fluid secretion such as cystic fibrosis.


Assuntos
Aquaporina 1/metabolismo , Doenças Autoimunes/metabolismo , Membrana Celular/metabolismo , Ductos Pancreáticos/metabolismo , Pancreatite/metabolismo , Doenças Autoimunes/patologia , Digestão/fisiologia , Humanos , Ductos Pancreáticos/patologia , Pancreatite/patologia
18.
J Gastroenterol ; 43(6): 403-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18600383

RESUMO

In 2002, the Japan Pancreas Society (JPS) was the first in the world to propose diagnostic criteria for autoimmune pancreatitis (AIP). Since the concept of AIP has changed with the accumulation of AIP cases, the Research Committee of Intractable Pancreatic Diseases (RCIPD) provided by the Ministry of Health, Labour and Welfare of Japan and the JPS issued revised clinical diagnostic criteria of AIP in 2006. The Asan Medical Center of Korea also proposed diagnostic criteria for AIP in 2006. However, there are subtle but clinically challenging differences between the Japanese and Korean criteria. This inconsistency makes it difficult to compare data in studies from different centers and elucidate the characteristics of AIP. To reach a consensus on AIP, the RCIPD and the Korean Society of Pancreatobiliary Diseases established the following Asian criteria for the diagnosis of AIP: I-1. Imaging studies of pancreatic parenchyma show a diffuse/segmental/focally enlarged gland, occasionally with a mass and/or a hypoattenuation rim. I-2. Imaging studies of pancreaticobiliary ducts show diffuse/segmental/focal pancreatic ductal narrowing, often with stenosis of the bile duct. (Both I-1 and I-2 are required for diagnosis). II. Elevated level of serum IgG or IgG4, and detection of autoantibodies. III. Common lymphoplasmacytic infiltration and fibrosis, with abundant IgG4-positive cell infiltration. AIP should be diagnosed when criterion I and one of the other two criteria are satisfied, or when histology shows the presence of lymphoplasmacytic sclerosing pancreatitis in the resected pancreas. A diagnostic trial of steroid therapy can be applied carefully by expert pancreatologists only in patients fulfilling criterion I alone with negative diagnostic work-up results for pancreatobiliary cancer.


Assuntos
Doenças Autoimunes/diagnóstico , Pancreatite/diagnóstico , Doenças Autoimunes/tratamento farmacológico , Humanos , Pancreatite/tratamento farmacológico
19.
J Gastroenterol Hepatol ; 23 Suppl 1: S69-72, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18336668

RESUMO

Chronic and excessive consumption of alcohol is an important factor responsible for the onset of pancreatitis. However, the incidence of chronic pancreatitis in heavy drinkers differs in individuals, suggesting that these individual differences may involve various genetic and environmental factors. In the present study, we investigated an association of alcoholic pancreatitis with polymorphisms of the various genes related to metabolism of the oxidative compounds. We analyzed polymorphisms of NADPH-quinone oxidoreductase 2 (NQO2), multidrug resistance 1 (MDR1), alcohol dehydrogenase 1B (ADH1B) and lipoprotein lipase (LPL). The subjects consisted of 53 patients with chronic alcoholic pancreatitis (AlCP), 54 alcoholic patients without pancreatic dysfunction (Alc), and 42 healthy individuals. DNA samples were prepared from the peripheral blood of all subjects, and the genetic mutations were analyzed by polymerase chain reaction and restriction fragment length polymorphism methods. The ADH1B gene frequencies were significantly different between healthy controls and Alc patients (P < 0.001), and also between AlCP and Alc patients (P < 0.05). However, no significant difference was found between healthy controls and AlCP patients. The gene frequencies of MDR1 (3435C > T) and MDR1 (2677G > A/T) of patients with AlCP or Alc were different when compared with healthy controls, although the difference was not significant. The NQO2 and LPL genes showed no relation with Alc and AlCP patients. The ADH1B*1 gene frequency in AlCP was significantly lower compared with Alc. We speculate that the ADH1B*1 gene may function by reducing vulnerability to the onset of alcoholic pancreatitis. Other genes analyzed in the present study lacked association with AlCP.


Assuntos
Pancreatite Alcoólica/genética , Polimorfismo Genético , Humanos , Pessoa de Meia-Idade
20.
Auton Neurosci ; 138(1-2): 31-40, 2008 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-17936693

RESUMO

Long-term diabetic patients exhibit major clinical gastrointestinal problems, such as diarrhea and constipation. In recent years, water channel protein, aquaporin 1 (AQP1) has been identified in the enteric nervous system (ENS). We have examined the pathological changes in AQP1 immunoreactive (IR) neurons in streptozotocin-induced (STZ) diabetic rats. Eight-week-old Wistar rats were injected with streptozotocin, and artificial diabetes was induced. Sixteen-week-old STZ rats were then examined with double immunofluorescence staining and ABC immunohistochemical staining. AQP1-IR neurons in STZ rats were significantly increased compared with control rats (p<0.01). The ratio of AQP1 vs. HuC/D in STZ rats was also clearly increased as compared with control rats (p<0.05). It was apparent that thick AQP1-IR fibers were frequently observed in the secondary and tertiary myenteric plexus of STZ rats. The AQP1-IR fibers of STZ rats conspicuously showed many swollen varicosities. These swollen varicose fibers were also observed in the longitudinal and circular muscle layers. Streptozotocin-induced diabetic rats showed pathological changes in AQP1-IR neurons of the ENS. The alteration of AQP1-IR neurons may be possible contribute to diabetic gastrointestinal dysfunction in streptozotocin-induced diabetic rats.


Assuntos
Aquaporina 1/metabolismo , Complicações do Diabetes/patologia , Diabetes Mellitus Experimental/complicações , Sistema Nervoso Entérico/patologia , Gastroenteropatias/patologia , Neurônios/patologia , Animais , Axônios/metabolismo , Axônios/patologia , Contagem de Células , Complicações do Diabetes/metabolismo , Complicações do Diabetes/fisiopatologia , Sistema Nervoso Entérico/metabolismo , Sistema Nervoso Entérico/fisiopatologia , Imunofluorescência , Gastroenteropatias/metabolismo , Gastroenteropatias/fisiopatologia , Imuno-Histoquímica , Intestino Delgado/inervação , Intestino Delgado/fisiopatologia , Masculino , Músculo Liso/inervação , Plexo Mientérico/metabolismo , Plexo Mientérico/patologia , Plexo Mientérico/fisiopatologia , Neurônios/metabolismo , Ratos , Ratos Wistar , Regulação para Cima/fisiologia
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