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1.
Biochem Biophys Res Commun ; 686: 149163, 2023 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-37924667

RESUMO

The expression of brain-derived neurotrophic factor (BDNF) is observed not only in the brain, but also in peripheral tissues including white adipose tissues (WATs). Here, we showed that the mRNA expression of Bdnf in inguinal WAT (iWAT) and epididymal WAT (eWAT) increased within 2 weeks of feeding mice with a high-fat diet (HFD). In mice on a 2-week HFD, the induction of Bdnf expression in WATs was significantly correlated with increases in body weight, suggesting that Bdnf expression may increase at an early stage of obesity. The mRNA expression of hypoxia-inducible factor 1α and platelet-derived growth factor, which are involved in neovascularization and the subsequent expansion of adipose tissues, increased in the iWAT of mice on the 2-week HFD. We also found that the expression of macrophage marker F4/80 in iWAT increased under the HFD. Interestingly, HFD-induced Bdnf expression in iWAT was not observed when macrophages were removed by the administration of clodronate liposomes. Accordingly, mice receiving clodronate liposomes also exhibited a significant reduction in the HFD-induced increase in body weight. In conclusion, increased body weight in HFD-induced obese model mice was accompanied by the induction of Bdnf expression in iWAT and was probably mediated by macrophages. Our findings imply a novel function for BDNF in iWAT at an early stage of obesity.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Dieta Hiperlipídica , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ácido Clodrônico , Lipossomos/metabolismo , Tecido Adiposo Branco/metabolismo , Tecido Adiposo/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Peso Corporal , Macrófagos/metabolismo , RNA Mensageiro/metabolismo , Camundongos Endogâmicos C57BL
2.
Dis Esophagus ; 35(11)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35178563

RESUMO

Anastomotic stricture (AS) is one of the major complications after esophagectomy for esophageal cancer. We have previously reported that severe mucosal degeneration (MD) of the anastomotic site was associated with the incidence of AS. Meanwhile, there are few reports to correlate anastomotic internal circumference (AIC) with computed tomography (CT) with the incidence of AS. Therefore, this study was conducted to clarify the correlation of early postoperative endoscopic and CT findings with the incidence of AS. We assessed 205 patients who underwent esophagectomy. We then divided them into the non-AS group (n = 164) and the AS group (n = 41) and compared their background data and intraoperative and postoperative outcomes. We also evaluated the risk factors for AS using logistic regression model. Multivariate analysis revealed small AIC (P = 0.003; OR = 4.400; 95% CI = 1.650-11.700) and severe MD (P < 0.001; OR = 7.200; 95% CI = 2.650-19.600) as the independent risk factors for AS development. We also stratified the patients into the following four groups according to the incidence of AS: low-risk (normal AIC and intact or mild MD, 6.2%), intermediate-risk (small AIC and intact or mild MD, 29.4%), high-risk (normal AIC and severe MD, 42.9%), and very high-risk (small AIC and severe MD, 61.1%). Early postoperative endoscopic and CT findings were useful in predicting the development of AS after esophagectomy.


Assuntos
Neoplasias Esofágicas , Esofagectomia , Humanos , Esofagectomia/efeitos adversos , Esofagectomia/métodos , Constrição Patológica/etiologia , Neoplasias Esofágicas/complicações , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Medição de Risco , Tomografia Computadorizada por Raios X , Tomografia/efeitos adversos , Fístula Anastomótica/etiologia , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos
5.
Jpn J Radiol ; 42(2): 174-181, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37815695

RESUMO

OBJECTIVE: This study aims to retrospectively evaluate the outcomes of uterine artery embolization (UAE) for uterine fibroids (UFs), specifically submucosal UFs, according to the International Federation of Gynecology and Obstetrics (FIGO) classification of UFs. MATERIALS AND METHODS: Forty-two patients with symptomatic UFs underwent UAE with Embosphere® between July 2016 and November 2021. MRI was performed before, at 3 and 6 months after the UAE. At each examination, the volume of UF was measured, and the percentage volume reduction rate (VRR) was calculated. The technical success rate (TSR), symptom improvement rate (SIR), regrowth rate (RR) after 6 months, and adverse events (AEs) were examined; VRR was compared between patients with submucosal UFs (FIGO types 0-2, group A), those with submucosal contacts (FIGO type 3, group B), and those without submucosal UFs (FIGO types 4-7, group C). Statistical analysis was performed on the difference in VRR between groups A, B, and C at 3 and 6 months after UAE. The relationship with hormone levels before UAE and VRR was evaluated. RESULTS: Thirty-seven of the 42 patients were evaluated. Overall, VRR was 37.0% at 3 months and 52.1% at 6 months; TSR, SIR, and RR were 100%, 95.2%, and 5.4%, respectively; VRR at 6 months was 80.7% for group A (n = 7), 57.8% for group B (n = 13), and 37.1% for group C (n = 17). Significant differences were found between A and C (p < 0.001) and B and C (p = 0.023). Hormone levels before UAE had no effect on VRR. There was no significant AEs other than grade 3 pulmonary embolism in one patient. CONCLUSION: UAE was effective for submucosal FIGO types 0-3. UAE was especially useful as an option for FIGO type 3 with a low protrusion rate that is difficult to treat with transcervical resection.


Assuntos
Leiomioma , Embolização da Artéria Uterina , Neoplasias Uterinas , Gravidez , Feminino , Humanos , Neoplasias Uterinas/terapia , Estudos Retrospectivos , Resultado do Tratamento , Leiomioma/diagnóstico por imagem , Leiomioma/terapia , Hormônios
6.
Anticancer Res ; 43(5): 2211-2217, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37097660

RESUMO

BACKGROUND/AIM: The effectiveness of transanal total mesorectal excision (Ta-TME) in extended surgery (ES) has been discussed. This study examined the short-term outcomes of the first 31 patients who underwent Ta-TME after its introduction and verified the safety of Ta-TME in ES in the early stage following its introduction. PATIENTS AND METHODS: Thirty-one consecutive patients who underwent Ta-TME between December 2021 and January 2023 at our institution were included. The indications for Ta-TME were rectal tumors that could be palpated during rectal examination and bulky tumors that were deemed unresectable without Ta-TME. Short-term outcomes were retrospectively compared between patients who underwent normal Ta-TME, (n=27, TME group) and patients who underwent ES beyond TME (n=4, ES group). The data are shown as the median and interquartile range. Statistical analysis was performed with the Mann-Whitney U-test and Fisher's exact test. RESULTS: Total pelvic exenteration (TPE) was performed in the 4th and 8th patients; the 9th patient underwent a combined resection of the right adnexa and urinary bladder wall. The 31st patient underwent a combined resection of the uterus and the right adnexa. The operative time was 353 [285-471] vs. 569 [411-746] min for the TME and ES groups (p=0.039). Blood loss was 8 [5-40] vs. 45 [23-248] ml (p=0.065); postoperative hospital stay was 15 [10-19] vs. 11 [9-15] days (p=0.201); postoperative complications (higher than grade III) were 5 (19%) vs. 0 (p=1.000). Negative CRM was achieved in all cases. CONCLUSION: Ta-TME in ES was as safe as normal Ta-TME in the early stage after its introduction.


Assuntos
Laparoscopia , Protectomia , Neoplasias Retais , Feminino , Humanos , Estudos Retrospectivos , Resultado do Tratamento , Laparoscopia/efeitos adversos , Protectomia/efeitos adversos , Neoplasias Retais/patologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Reto/cirurgia , Reto/patologia
7.
Pediatr Int ; 54(4): 471-5, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22449275

RESUMO

BACKGROUND: The aim of the present study was to evaluate the role of interleukin (IL)-6-634 polymorphism in neonatal disorders such as bronchopulmonary dysplasia (BPD) and periventricular leukomalacia (PVL) in very low-birthweight (VLBW) infants. METHODS: This prospective cohort study included 202 infants (gestational age at birth, 23-34 weeks; birthweight, 500-1499 g). Genotypic analysis (polymerase chain reaction-restriction fragment length polymorphism) was performed with DNA extracted from whole-blood samples. RESULTS: Genotype distribution (66.8% CC, 28.2% CG, 5.0% GG) was similar to that in the adult Japanese population. BPD occurred in 85 infants (42.1%) among 202 VLBW infants. The duration of O(2) therapy in infants with CG/GG genotypes was significantly longer than that in infants with the CC genotype (CG/GG vs CC: 40.3 ± 52.2 days vs 28.4 ± 32.6 days, P < 0.05), but the prevalence of BPD was not associated with the CG/GG genotype (CG/GG, 40.0%; CC, 46.3%, P= 0.24). Infants with CG/GG genotypes were more likely to have received postnatal corticosteroid therapy for BPD than those with the CC genotype (CG/GG vs CC: 20.9% vs 11.1%, P = 0.05). PVL occurred in six infants (3.0%). There was no significant difference in the prevalence of PVL among IL-6-634 polymorphisms (CG/GG, 3.0%; CC, 3.0%, P = 0.65). CONCLUSIONS: IL-6-634 polymorphism is associated with duration of oxygen therapy in VLBW infants. This suggests that the IL-6-634 polymorphism G allele is an aggravating factor of BPD. IL-6-634 polymorphism is not associated with PVL.


Assuntos
Displasia Broncopulmonar/genética , Interleucina-6/genética , Leucomalácia Periventricular/genética , Polimorfismo de Nucleotídeo Único , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Masculino , Estudos Prospectivos
8.
No To Hattatsu ; 44(5): 392-6, 2012 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-23012869

RESUMO

We experienced a case of DiGeorge syndrome with left internal carotid artery absence probably causing one-and-a-half syndrome. MR angiogram demonstrated the apparent absence of the left internal carotid artery and consequently abnormal blood supply to the left middle cerebral artery, which was derived from the basilar artery via the left posterior communicating artery. The patient alsoshowed both an extremely narrow carotid canal on the left side and a very fine vessel extending to the terminal of the left internal carotid artery. Therefore, we regarded this abnormality as severe hypoplasia of left internal carotid artery and supposed that this hypoplasia had originated in maldevelopment of the third aortic arch based on the coexisting lower bifurcation of the right common carotid artery. Since the lesion of one-and-a-half syndrome is restricted to the pontine tegmentum, we speculated that it had resulted from ischemia of the basilar artery area during the embryonic period associated with the absence of the internal carotid artery. To our knowledge, DiGeorge syndrome has never been reported as a complication of internal carotid artery absence. The patient did not demonstrate either chromosome 22q11.2 deletion or TBX1 gene mutation, which is considered the gene responsible for 22q11.2 deletion syndrome. Therefore, the etiology of DiGeorge syndrome in this case remains unclear.


Assuntos
Artéria Carótida Interna/anormalidades , Síndrome de DiGeorge/complicações , Transtornos da Motilidade Ocular/complicações , Criança , Humanos , Masculino
9.
World J Clin Cases ; 10(32): 12015-12021, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36405265

RESUMO

BACKGROUND: The ascending pharyngeal artery (APhA) comprises the pharyngeal trunk (PT) and neuromeningeal trunk. The PT feeds the nasopharynx and adjacent tissue, which potentially connects with the sphenopalatine artery (SPA), branched from the internal maxillary artery (IMA). Due to its location deep inside the body, the PT is rarely injured by trauma. Here, we present two cases that underwent transcatheter arterial embolization (TAE) of the PT of the APhA due to trauma and iatrogenic procedure. CASE SUMMARY: Case 1 is a 49-year-old Japanese woman who underwent transoral endoscopy under sedation for a medical check-up. The nasal airway was inserted as glossoptosis occurred during sedation. Bleeding from the nasopharynx was observed during the endoscopic procedure. As the bleeding continued, the patient was referred to our hospital for further treatment. Contrast-enhanced computed tomography (CT) demonstrated extravasation in the nasopharynx originating from the right Rosenmuller fossa. TAE was performed and the extravasation disappeared after embolization. Case 2 is a 28-year-old Japanese woman who fell from the sixth floor of a building and was transported to our hospital. Contrast-enhanced CT demonstrated a complex facial fracture accompanying extravasation in the left pterygopalatine fossa to the nasopharynx. Angiography demonstrated an irregular third portion of the IMA. As angiography after TAE of the IMA demonstrated extravasation from the PT of the APhA, additional TAE to the artery was performed. The bleeding stopped after the procedure. CONCLUSION: Radiologists should be aware that the PT of the APhA can be a bleeding source, which has a potential connection with the SPA.

10.
J Hum Genet ; 56(1): 77-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20944642

RESUMO

Trichothiodystrophy (TTD) is a rare autosomal recessive disorder characterized by sulfur-deficient brittle hair complicated with ichthyosis, physical and mental retardation, and proneness to infections. Approximately half of TTD patients exhibit cutaneous photosensitivity because of the defect of nucleotide excision repair. Three genes, XPB, XPD and TTDA, have been identified as causative genes of photosensitive TTD. These three genes are components of basal transcription factor IIH. Most TTD cases have been reported in Europe and North America. We report a severely affected Japanese TTD patient with XPD mutations. Interestingly, his father has ichthyotic skin. The alteration in the paternal allele was a nucleotide substitution leading to Arg-722 to Trp (R722W), as previously reported in TTD patients. The other alteration in the maternal allele was a novel 3-bp deletion at nucleotides 67-69, resulting in the deletion of Ser-23, which is located upstream of helicase motif I and is the closest to the N-terminal end of XPD in reported mutations. The expression study showed that the two alterations were causative mutations for TTD. In Asia, it is likely that there are TTD patients who have not been diagnosed.


Assuntos
Povo Asiático/genética , Proteína Grupo D do Xeroderma Pigmentoso/genética , Sequência de Bases , Pré-Escolar , Análise Mutacional de DNA , Humanos , Masculino , Síndromes de Tricotiodistrofia/genética
11.
J Biol Chem ; 284(51): 35872-84, 2009 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-19858219

RESUMO

Human diseases caused by mutations in extracellular matrix genes are often associated with an increased risk of cataract and lens capsular rupture. However, the underlying mechanisms of cataract pathogenesis in these conditions are still unknown. Using two different mouse models, we show that the accumulation of collagen chains in the secretory pathway activates the stress signaling pathway termed unfolded protein response (UPR). Transgenic mice expressing ectopic Col4a3 and Col4a4 genes in the lens exhibited activation of IRE1, ATF6, and PERK associated with expansion of the endoplasmic reticulum and attenuation of general protein translation. The expression of the transgenes had adverse effects on lens fiber cell differentiation and eventually induced cell death in a group of transgenic fiber cells. In Col4a1(+/Deltaex40) mutant mice, the accumulation of mutant chains also caused low levels of UPR activation. However, cell death was not induced in mutant lenses, suggesting that low levels of UPR activation are not proapoptotic. Collectively, the results provide in vivo evidence for a role of UPR in cataract formation in response to accumulation of terminally unfolded proteins in the endoplasmic reticulum.


Assuntos
Autoantígenos/biossíntese , Catarata/metabolismo , Colágeno Tipo IV/biossíntese , Retículo Endoplasmático/metabolismo , Cristalino/metabolismo , Transdução de Sinais , Resposta a Proteínas não Dobradas , Fator 6 Ativador da Transcrição/genética , Fator 6 Ativador da Transcrição/metabolismo , Animais , Autoantígenos/genética , Catarata/genética , Catarata/patologia , Morte Celular/genética , Colágeno Tipo IV/genética , Modelos Animais de Doenças , Retículo Endoplasmático/genética , Retículo Endoplasmático/patologia , Humanos , Cristalino/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transgenes/genética , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo
12.
Pediatr Nephrol ; 25(6): 1169-72, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20130921

RESUMO

Alport syndrome (AS) is caused by mutations in type IV collagen alpha3, alpha4, and alpha5 chains. The three chains form a heterotrimer. We have previously shown that all 15 types of recombinant alpha5(IV) chains with mutations, corresponding to AS mutations, in the noncollagenous (NC1) domain are defective in terms of heterotrimer formation and/or secretion of the heterotrimer from cells. A relatively large family with Cys1638Tyr in the NC1 domain of the alpha5(IV) chain has been found to have mild AS phenotypes without hearing loss or ocular abnormalities. Renal biopsies of different family members also revealed the presence of the alpha3(IV), alpha4(IV), and alpha5(IV) chains in the glomerular basement membrane. In our study, we introduced the mutation corresponding to Cys1638Tyr into the alpha5(IV) chain and characterized the mutant chain. In cells containing the mutant-type alpha5(IV) chain, heterotrimer formation in the cells and secretion of the alpha5(IV) chain in the monomeric form from the cells were markedly decreased compared with cells containing the wild-type chain. However, the heterotrimer that was formed from the mutant chain was still able to be secreted from the cells. The residual ability of the mutant chain may have led to the unique phenotypes found in the AS family with the Cys1638Tyr mutation.


Assuntos
Colágeno Tipo IV/química , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Nefrite Hereditária/genética , Nefrite Hereditária/metabolismo , Animais , Humanos , Camundongos , Mutação
13.
Int J Infect Dis ; 100: 283-285, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829044

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak is rising globally. However, clinically effective antiviral treatments are not established. Favipiravir may prevent pneumonia and acute respiratory distress syndrome aggravation. We describe SARS-CoV-2-positive patients, two of whom were in a critical condition and one of whom was in a severe condition, who were administered favipiravir for their deteriorating conditions and cured.


Assuntos
Amidas/uso terapêutico , Antivirais/uso terapêutico , Pirazinas/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Resultado do Tratamento
14.
Biochem Biophys Res Commun ; 366(1): 60-5, 2008 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18083113

RESUMO

Alport syndrome (AS) is caused by mutations in type IV collagen alpha3, alpha4, and alpha5 chains. The three chains form a heterotrimer. In this study, we introduced 12 kinds of missense and three kinds of nonsense mutations, corresponding to AS mutations, into the NC1 domain of alpha5(IV) and characterized the mutant chains. Nine alpha5(IV) chains with amino acid substitutions and all three truncated alpha5(IV) chains did not form a heterotrimer and were not secreted from cells. Three alpha5(IV) chains with amino acid substitutions did, however, form heterotrimers in cells, but these were not secreted from cells. These findings indicate that a defect in heterotrimer formation is the main molecular mechanism underlying the pathogenesis of AS caused by mutation in the NC1 domain. We also showed that even a single amino acid deletion in the carboxyl-terminal region markedly affected the heterotrimerization, indicating that the carboxyl-terminal end is indispensable for heterotrimer formation.


Assuntos
Colágeno Tipo IV/química , Colágeno Tipo IV/metabolismo , Rim/metabolismo , Substituição de Aminoácidos , Sítios de Ligação , Linhagem Celular , Dimerização , Humanos , Mutagênese Sítio-Dirigida , Ligação Proteica
16.
Am J Med Genet ; 110(3): 248-52, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12116233

RESUMO

Xeroderma pigmentosum (XP) is a sun-sensitive and cancer-prone genetic disorder consisting of seven genetically distinct complementation groups (groups A-G). XP group D (XP-D) is a heterogeneous group. Mutations in the XPD gene (XPD) can exhibit three distinct clinical phenotypes: XP, trichothiodystrophy (TTD), or XP combined with Cockayne syndrome. XPD protein is required for both nucleotide excision repair (NER) and basal transcription. Therefore, different mutations in XPD may affect NER and transcription activities to various degrees and result in such diverse phenotypes. In this study, we identified six causative mutations, two of which have not been described, in five XP-D cell strains tested. The cell strains were all compound heterozygotes with different mutations. In all cell strains, one allele was thought to be functionally null and the other was a less severe allele with R683W, R683Q, and R666W substitutions. The second allele in each strain was specific to the XP phenotype. The findings are consistent with the hypothesis that the site of mutation of the XPD gene determines the clinical phenotype, XP or TTD.


Assuntos
DNA Helicases , Proteínas de Ligação a DNA , Proteínas/genética , Fatores de Transcrição , Xeroderma Pigmentoso/genética , Adulto , Idoso , Sequência de Bases , Células Cultivadas , Criança , Análise Mutacional de DNA , DNA Complementar/química , DNA Complementar/genética , Feminino , Genótipo , Humanos , Masculino , Mutação , Mutação de Sentido Incorreto , Fenótipo , Deleção de Sequência , Xeroderma Pigmentoso/patologia , Proteína Grupo D do Xeroderma Pigmentoso
17.
Leuk Lymphoma ; 45(11): 2303-6, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15512821

RESUMO

To clarify the mechanism of progression and acquired drug resistance of leukemia, we searched for an overexpressed gene in drug-resistant leukemia cells and identified an approximately 5-kb transcript by using the subtraction method. The nucleotide sequence of the gene was highly homologous to those of human endogenous retrovirus (HERV) transcripts. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that the gene was overexpressed in cells from 6 childhood acute lymphoblastic leukemia patients (60%) but not in bone marrow cells at remission. Peripheral blood mononuclear cells from normal controls (n=11) and bone marrow cells from non-leukemia patients (n=13) did not express the gene. These findings indicate that the gene may play a role in leukemogenesis and may be a novel leukemia marker. Further studies on the functional role of the gene are needed.


Assuntos
Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/virologia , Adolescente , Biomarcadores Tumorais , Northern Blotting , Células da Medula Óssea/metabolismo , Linhagem Celular Tumoral , Criança , Pré-Escolar , Clonagem Molecular , DNA Complementar/metabolismo , Progressão da Doença , Humanos , Lactente , Leucócitos Mononucleares/metabolismo , Reação em Cadeia da Polimerase , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , RNA Mensageiro/metabolismo , Indução de Remissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
18.
Biomed Res ; 31(6): 371-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21187648

RESUMO

We previously established stable transformants of the human embryonic kidney 293 (HEK293) cell line that express type IV collagen α3, α4 and wild-type or mutant-type α5 chains. Using these cell lines, we confirmed that these three chains form a heterotrimer and that α5 chains containing mutations seen in Alport syndrome are defective in heterotrimerization. In these studies, the amount of heterotrimer that formed was much less than expected relative to the amount of α(IV) chains expressed. The aim of the present study was to determine the effect of the collagen-specific molecular chaperone heat shock protein 47 (HSP47), whose expression is low in HEK293 cells, on the heterotrimerization of α3(IV), α4(IV) and α5(IV) chains. Reduction of HSP47 levels by siRNA resulted in defects of heterotrimerization among the three chains, indicating that HSP47 plays a critical role in the heterotrimerization. On the other hand, overexpression of HSP47 did not influence heterotrimerization. Since many enzymes and molecular chaperons assist correct folding and trimerization of collagens, one or more enzymes and/or molecular chaperones, other than HSP47, might be deficient in HEK293 cells. Overexpression of HSP47 decreased the secretion of heterotrimers containing the mutant α5(IV) chain, suggesting that HSP47 overexpression might enhance the quality control mechanisms of collagen synthesis by inhibiting the secretion of incorrectly structured heterotrimers.


Assuntos
Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Proteínas de Choque Térmico HSP47/genética , Mutação , Multimerização Proteica , Células HEK293 , Proteínas de Choque Térmico HSP47/metabolismo , Humanos , Glomérulos Renais/metabolismo , Nefrite Hereditária/genética , Nefrite Hereditária/metabolismo
19.
Nihon Rinsho ; 62 Suppl 5: 87-92, 2004 May.
Artigo em Japonês | MEDLINE | ID: mdl-15197893
20.
Kidney Int ; 64(6): 1986-96, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14633121

RESUMO

BACKGROUND: Alport syndrome is caused by mutations in type IV collagen alpha3, alpha4, and alpha5 genes. Immunohistochemical analyses of kidney sections from normal individuals and Alport syndrome patients have suggested that the alpha3(IV), alpha4(IV), and alpha5(IV) chains form a heterotrimer in the glomerular basement membrane (GBM) and that a defect in any one of the chains disrupts the assembly of the three chains, resulting in Alport syndrome. METHODS: We established stable transformants of HEK293 cells that expressed mouse alpha3(IV) and/or alpha4(IV) and/or alpha5(IV) chains. Using cell extracts and culture media of these cells, experiments were performed to determine whether or not the alpha3(IV) and alpha4(IV) chains were coimmunoprecipitated with the alpha5(IV) chain. Moreover, we examined complex formation of mutant alpha5(IV) chain containing either a deletion or substitution mutation with the alpha3(IV) and alpha4(IV) chains. RESULTS: The established cell strains were named according to their transfected alpha(IV) chains. The alpha3(IV) and alpha4(IV) chains were coimmunoprecipitated with the alpha5(IV) chain in alpha345 cells but not in alpha35 and alpha45 cells. These chains were not coimmunoprecipitated with the alpha5(IV) chain, which lacked either a collagenous domain or NC1 domain. The ability of the alpha5(IV) chain with either a G1182R or C1573R substitution, corresponding to previously reported mutations in Alport syndrome patients, to form a complex with alpha3(IV) and alpha4(IV) chains was diminished. CONCLUSION: The findings indicate that alpha3(IV), alpha4(IV), and alpha5(IV) chains form a complex, which is a heterotrimer, and that a defect in complex formation might be one of the molecular mechanisms underlying the pathogenesis of Alport syndrome.


Assuntos
Autoantígenos/genética , Colágeno Tipo IV/genética , Processamento de Proteína Pós-Traducional , Substituição de Aminoácidos , Animais , Arginina/genética , Linhagem Celular , Cisteína/genética , Deleção de Genes , Glicina/genética , Humanos , Camundongos , Nefrite Hereditária/genética , Proteínas Recombinantes/genética , Transfecção
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