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1.
Pediatr Surg Int ; 39(1): 286, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37919436

RESUMO

BACKGROUND/PURPOSE: Whether Roux-en-Y hepatic jejunectomy (HJ) or duct-to-duct biliary reconstruction (DD) is more useful in pediatric living donor liver transplantation has not yet been fully investigated. Therefore, to assess the feasibility and safety of DD, we compared the surgical outcomes of DD to HJ. METHODS: We divided 45 patients, excluding those with biliary atresia, into the DD group (n = 20) and the HJ group (n = 25), according to the type of biliary reconstruction they received. RESULTS: The 5-year survival rates (DD vs. HJ = 79.7% vs. 83.6%, p = 0.70) and the incidence of biliary complications, including bile leakage and stricture (DD vs. HJ = 1 [5.0%] vs. 1 [4.0%], p = 0.87) were not significantly different between the groups. However, intestinal complications, including bowel perforation or ileus, were significantly common in the HJ group (9/25 [36.0%]) than in the DD group (1/20 [5.0%]; p = 0.01). The three patients in the HJ group with intestinal perforation all suffered perforation at the anastomosed site in the Roux-en-Y procedure. The subgroup analysis showed the non-inferiority of DD to HJ for biliary or intestinal complications in patients weighting < 10 kg. CONCLUSION: With a proper selection of cases, DD should be a safe method for biliary reconstruction in pediatric recipients with little risk of biliary complications equivalent to HJ and a reduced risk of intestinal complications.


Assuntos
Doenças Biliares , Procedimentos Cirúrgicos do Sistema Biliar , Transplante de Fígado , Humanos , Criança , Transplante de Fígado/métodos , Doadores Vivos , Fígado/cirurgia , Anastomose em-Y de Roux/métodos , Doenças Biliares/cirurgia , Ductos Biliares/cirurgia , Procedimentos Cirúrgicos do Sistema Biliar/métodos , Anastomose Cirúrgica , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos
2.
Surg Today ; 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37668735

RESUMO

Hirschsprung disease (HSCR) and its associated disorders (AD-HSCR) often result in severe hypoperistalsis caused by enteric neuropathy, mesenchymopathy, and myopathy. Notably, HSCR involving the small intestine, isolated hypoganglionosis, chronic idiopathic intestinal pseudo-obstruction, and megacystis-microcolon-intestinal hypoperistalsis syndrome carry a poor prognosis. Ultimately, small-bowel transplantation (SBTx) is necessary for refractory cases, but it is highly invasive and outcomes are less than optimal, despite advances in surgical techniques and management. Thus, regenerative therapy has come to light as a potential form of treatment involving regeneration of the enteric nervous system, mesenchyme, and smooth muscle in affected areas. We review the cutting-edge regenerative therapeutic approaches for managing HSCR and AD-HSCR, including the use of enteric nervous system progenitor cells, embryonic stem cells, induced pluripotent stem cells, and mesenchymal stem cells as cell sources, the recipient intestine's microenvironment, and transplantation methods. Perspectives on the future of these treatments are also discussed.

3.
J Pediatr Surg ; 58(7): 1246-1251, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36914460

RESUMO

PURPOSE: The aim of this study was to clarify the appropriate management after birth for congenital biliary dilatation (CBD, choledochal cyst) patients with a prenatal diagnosis. METHOD: Thirteen patients with a prenatal diagnosis of CBD who underwent liver biopsy during excision surgery were divided into two groups and retrospectively analyzed: group A, with liver fibrosis above F1 and group B, without liver fibrosis. RESULTS: Excision surgery was performed earlier in group A (F1-F2), at a median of 106 days old (p = 0.04). There were significant differences between the two groups in the presence symptoms and sludge, the cyst size, and the level of serum bilirubin and gamma glutamyl transpeptidase (GGT) before excision surgery (p < 0.05). Especially, in group A, prolonged serum GGT elevation and larger cysts were consistently observed from birth. The cut-off values of predictions for the presence of liver fibrosis in serum GGT and cyst size were 319 U/l and 45 mm. No significant differences were observed in the postoperative liver function or complications during the follow-up period. CONCLUSION: In patients with prenatally diagnosed CBD, the postnatal serial changes of serum GGT values and cyst size, in addition to symptoms, could help to prevent progressive liver fibrosis. LEVEL OF EVIDENCE: Ⅲ. TYPE OF STUDY: Treatment Study.


Assuntos
Cisto do Colédoco , Gravidez , Feminino , Humanos , Cisto do Colédoco/diagnóstico , Cisto do Colédoco/cirurgia , Estudos Retrospectivos , Diagnóstico Pré-Natal , Biópsia , gama-Glutamiltransferase , Cirrose Hepática
4.
J Org Chem ; 87(12): 8118-8125, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35657258

RESUMO

N-Methyl-2-methoxymethylanilines 1 bearing various 5-substituted-pyrimidin-2-yl groups were prepared, and their rotational behaviors were explored in detail. It was revealed that the rotational barriers around two N-Ar bonds increase in proportion to the electron-withdrawing ability of substituents X at the 5-position.

5.
J Pediatr Surg ; 57(7): 1269-1273, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35393117

RESUMO

BACKGROUND: Immaturity of ganglia (IG), an allied disorder of Hirschsprung disease (AD-HSCR), develops as neonatal ileus, but the dysmotility spontaneously resolves after several months. The diagnosis of IG using HE staining is often difficult. We herein report a new pathological finding of IG called the 'palisading-like pattern', which may be helpful for improving the diagnostic accuracy. METHODS: Cases of IG that were managed over the past 28 years were retrospectively reviewed. We investigated the clinical course and pathological findings for Hematoxylin-Eosin (HE) staining. The conventional diagnostic criteria for IG were (1) a normal or slightly increased number of ganglion cells and (2) ganglion cells with small nuclei. RESULTS: Among the 155 cases, 28 were diagnosed with IG, and 10 were retrospectively confirmed by HE staining. A palisading-like pattern was confirmed at the time of the initial ileostomy (median age, 2.5 days), and the palisading-like pattern had completely disappeared by the time of stoma closure (median age, 215 days) in all 10 cases. A palisading-like pattern is not present in other diseases. CONCLUSIONS: Even if immunostaining data are not available for a further analysis, the detection of a palisading-like pattern on HE staining makes an accurate diagnosis possible. LEVEL OF EVIDENCE: LEVEL IV.


Assuntos
Doença de Hirschsprung , Obstrução Intestinal , Pré-Escolar , Gânglios/patologia , Doença de Hirschsprung/diagnóstico , Doença de Hirschsprung/patologia , Humanos , Ileostomia , Recém-Nascido , Obstrução Intestinal/patologia , Plexo Mientérico/patologia , Estudos Retrospectivos
6.
Surg Case Rep ; 6(1): 321, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33315167

RESUMO

BACKGROUND: Biliary atresia in very low birth weight (VLBW) and extremely low birth weight (ELBW) infants is rarely reported, and the optimal timing of Kasai portoenterostomy (KPE) in these cases remains unclear. CASE PRESENTATION: We report a case of biliary atresia in a preterm female infant of 24 weeks of gestation who weighed 824 g. She underwent exploratory laparotomy and intraoperative cholangiography at 58 days of age (weight, 1336 g). Despite the diagnosis of biliary atresia with a type I cyst, we could only perform gallbladder drainage at that time due to the unstable intraoperative condition. While we waited for her body weight to increase, KPE was performed at 122 days of age (corrected age: 16 days), when the patient weighed 2296 g. Although she initially became jaundice-free, her liver function deteriorated due to cholangitis, and she developed decompensated cholestatic liver cirrhosis. Living donor liver transplantation was successfully performed at 117 days after KPE, and the postoperative course was uneventful. The timing of KPE is difficult to determine and a review of the relevant literature revealed that a poor prognosis in VLBW and ELBW infants with BA. CONCLUSIONS: Early KPE and careful postoperative follow-up, including liver transplantation is important for the improvement of outcomes.

7.
Urology ; 145: 236-242, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32739309

RESUMO

OBJECTIVE: To evaluate the effect of laparoscopic percutaneous extraperitoneal closure (LPEC) of the internal inguinal ring for the treatment in pediatric abdominoscrotal hydrocele (ASH) and to assess the feasibility and safety of the procedures. PATIENTS AND METHODS: Data were collected from the charts of patients with ASH who underwent surgery in Kokura Medical Center from April 2014 to December 2019. The patients' characteristics, preoperative diagnosis, forms of abdominal components, presence of patent processus vaginalis (PPV), associated pathologies, and postoperative results were evaluated. RESULTS: The study population included 10 patients (4.3% of all 230 hydroceles). The mean age of 10 patients was 3.5 years (range, 7 months to 7 years). A preoperative diagnosis of ASH was made in 3 patients. In the other 7 patients, ASH was detected during laparoscopic repair of the scrotal hydrocele. The abdominal forms of hydrocele were monolocular cysts (n = 6) and multilocular cysts (n = 4). PPV was detected by laparoscopy in all cases. Six patients had contralateral pathologies, including PPV (n = 4), inguinal hernia (n = 1), and scrotal hydrocele (n = 1). One patient had ipsilateral undescended testis. Preoperative ultrasonography showed some degree of testicular dysmorphism on the affected side in 4 cases. In all cases, treatment was accomplished by closing the PPV at the internal inguinal ring by LPEC procedures. No patients had postoperative complications, including recurrent ASH or hydrocele after ASH repair (mean follow-up, 2.6 years). CONCLUSION: LPEC may be an adequate and minimally invasive method for the treatment of the pediatric ASH.


Assuntos
Laparoscopia , Hidrocele Testicular/cirurgia , Criança , Pré-Escolar , Estudos de Viabilidade , Humanos , Lactente , Laparoscopia/efeitos adversos , Masculino , Procedimentos Cirúrgicos Urológicos Masculinos/efeitos adversos , Procedimentos Cirúrgicos Urológicos Masculinos/métodos
8.
J Org Chem ; 85(7): 5109-5113, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32138515

RESUMO

The addition of methanesulfonic acid to N-(2,6-dimethylpyridin-4-yl)-N-methyl-2-iso-propylaniline led to the selective protonation of the pyridine nitrogen atom, resulting in a significant deceleration of the rotation rates around both N-pyridyl and N-(i-Pr)phenyl bonds through a relayed brake mechanism.

9.
Surg Today ; 50(7): 783-786, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31720827

RESUMO

Laparoscopic gastrostomy tube placement has been increasingly adopted by pediatric surgeons. We herein report our experience with the performance of a laparoscopic-assisted Stamm-operation inside the minimal trocar site without the extension of the trocar site incision or mini-laparotomy. We present some technical modifications that facilitate suturing inside the minimal trocar site. METHODS: A retrospective chart review was conducted of cases involving patients who underwent laparoscopic-assisted gastrostomy, using a simple extracorporeal method inside the trocar site from April 1998 to March 2018. RESULTS: One hundred five gastrostomy tubes were placed in a laparoscopic-assisted operation. All but two of the cases involved patients with neurological impairment. The mean age was 12.5 years; 28 cases were > 16 years of age. Seventy-five cases underwent gastrostomy during laparoscopic fundoplication. All gastrostomy procedures were completed without intraoperative difficulties; however, 8 cases, which involved a thick abdominal wall, required extension of the trocar site. No cases required conversion to open gastrostomy. No major complications were observed. Two patients developed continuous peristomal cellulitis after surgery, due to the mismatch of the site position and an unsuitable button device size. CONCLUSION: We demonstrated that laparoscopic gastrostomy with fully extracorporeal suturing within the trocar site is feasible and beneficial, especially for the most neurologically impaired pediatric cases. Technical modification, changing the order of the process, and suturing technique in the minimal space, made it easier to perform the procedures inside the minimal trocar hole.


Assuntos
Gastrostomia/métodos , Laparoscopia/métodos , Técnicas de Sutura , Suturas , Adolescente , Criança , Estudos de Viabilidade , Feminino , Fundoplicatura/métodos , Humanos , Masculino , Estudos Retrospectivos , Instrumentos Cirúrgicos
10.
Surg Case Rep ; 5(1): 111, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292778

RESUMO

BACKGROUND: Although uncommon and seldom experienced, intestinal perforation is a well-known complication of Hirschsprung's disease (HD). A literature review revealed that the cecum, including the appendiceal base, is a site of perforation. The cecum is not suitable for making an ordinary loop colostomy, and the optimal operative strategy remains to be established. CASE PRESENTATION: We present a combination technique composed of tangential cecostomy at the perforated portion and postoperative care with a transanal indwelling tube, which was used in the treatment of a 3-day-old boy with cecal perforation with long-segment Hirschsprung's disease. A temporary simple blowhole stoma and continuous decompression with daily irrigation via a transanal indwelling tube in the distal colon achieved a secure recovery and was followed by a definitive operation in the early period. The combination of tangential cecostomy and transanal indwelling catheter management led to the preservation of the ileocecal valve. CONCLUSIONS: We review the Japanese literature and emphasize the usefulness of this combination technique by blowhole tangential cecostomy and transanal tube insertion for neonatal cecal perforation in patients with HD in today's early definitive operation era.

11.
J Pediatr Surg ; 52(10): 1621-1624, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28410789

RESUMO

PURPOSE: We examined the clinical significance of duodenogastric regurgitation (DGR) as a late complication in the long-term follow-up after hepaticoduodenostomy (HD) as a reconstruction surgery for congenital biliary dilatation (CBD). METHODS: Seventeen patients with CBD were retrospectively analyzed for late complications (mean follow-up, 16.8 years). All patients had undergone total resection of the extrahepatic bile duct followed by HD. DGR was identified using endoscopic examination, intraluminal bile monitoring, and liver scanning. RESULTS: DGR was found in all 17 patients by endoscopic examination and intraluminal bile monitoring. Fourteen of the 17 (82.4%) patients with DGR had experienced abdominal symptoms since a mean of 6.9 years postoperatively. Liver scanning also revealed apparent DGR in all 14 symptomatic patients. We converted 7 of the 14 patients to hepaticojejunostomy reconstruction at a mean of 13.0 years after the initial excisional surgery. Their symptoms were completely relieved postoperatively. CONCLUSIONS: DGR is an important complication after HD. Examination of patients for the development of DGR is an essential part of long-term follow-up in patients with CBD who have undergone HD as a reconstruction surgery. Conversion surgery is recommended in patients with DGR accompanied by long-term abdominal symptoms. LEVELS OF EVIDENCE: Level IV.


Assuntos
Anastomose Cirúrgica/efeitos adversos , Procedimentos Cirúrgicos do Sistema Biliar/efeitos adversos , Cisto do Colédoco/cirurgia , Refluxo Duodenogástrico/etiologia , Adolescente , Sistema Biliar , Procedimentos Cirúrgicos do Sistema Biliar/métodos , Criança , Dilatação Patológica/cirurgia , Feminino , Humanos , Lactente , Masculino , Adulto Jovem
12.
Yakugaku Zasshi ; 129(8): 949-55, 2009 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-19652501

RESUMO

The control of delayed emesis is very important in order to continue ambulatory chemotherapy. We performed retrospective study that examined the efficacy of preventive treatment (granisetron+dexamethasone+domperidone) for delayed emesis induced by FOLFOX4 chemotherapy for advanced and recurrent colorectal cancer. The subjects were 92 patients who underwent FOLFOX4 chemotherapy at the Cancer Institute Hospital of JFCR (group with preventive treatment: 50, group without preventive treatment: 42), and the observation period was set as the 1st-9th cycle. The complete nausea inhibition rate was 50.0% in the group with and 21.5% in the group without preventive treatment, showing a significantly higher inhibition rate in the former (p=0.0047). The complete vomiting inhibition rates were 86.0% and 66.7%, respectively, again showing a significantly higher inhibition rate in the former (p=0.015). On multivariate analysis (multiple logistic analysis), the development of nausea/vomiting and preventive treatment for delayed emesis were significantly associated, showing that the treatment was an independent preventive factor. All adverse reactions induced by preventive treatment were mild, suggesting no safety-related problem. These findings suggested the usefulness of preventive treatment with granisetron, dexamethasone, and domperidone for FOLFOX4 chemotherapy-induced delayed emesis.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Dexametasona/uso terapêutico , Domperidona/uso terapêutico , Granisetron/uso terapêutico , Vômito/induzido quimicamente , Vômito/prevenção & controle , Adulto , Idoso , Neoplasias Colorretais/tratamento farmacológico , Quimioterapia Combinada , Feminino , Fluoruracila/efeitos adversos , Humanos , Leucovorina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Compostos Organoplatínicos/efeitos adversos , Estudos Retrospectivos
13.
Anal Bioanal Chem ; 391(4): 1263-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18157663

RESUMO

A bioelectronic sensor for triethylamine (TEA) was developed with a flavin-containing monooxygenase type 3 (FMO-3). The TEA biosensor consisted of a Clark-type dissolved-oxygen electrode and an FMO-3 immobilized membrane. The FMO-3 solution was mixed with a poly(vinyl alcohol) containing stilbazolium groups (PVA-SbQ), coated on to the dialysis membrane, and the membrane was irradiated with a fluorescent light to immobilize the enzyme. In order to amplify the biosensor output, a substrate regeneration cycle, obtained by coupling the monooxygenase with L-ascorbic acid (AsA) as reducing reagent system, was applied. The effect of pH on the determination of TEA was studied. The maximum response was achieved at pH >9.0. A drop of the phosphate buffer solution with the AsA was put on the sensing area of the oxygen electrode, and the FMO-3 immobilized membrane was placed on the oxygen electrode and covered with a supporting Nylon mesh net which was secured with a silicone O-ring. A measurement system for TEA solution was constructed using the FMO-3 biosensor, a personal computer, a computer-controlled potentiostat, and an A/D converter. The FMO-3 biosensor was used to measure TEA solution from 0.5 to 4.0 mmol L(-1) with 10.0 mmol L(-1) AsA. The biosensor also had good reproducibility, for example a 6.31% coefficient of variation for five measurements, and the output current was maintained over a few hours. In order to improve the selectivity of the TEA biosensor, three type of biosensor with FMO isomer types 1, 3, and 5 were constructed and used to measure nitrogen and sulfur compounds. The outputs of the isomer biosensors indicated individual patterns for each sample solution. The selectivity of TEA biosensor would be improved, and determination of sulfur and nitrogen compounds would be possible, by using the different output of biosensors prepared from different FMO isomers.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Etilaminas/química , Oxigenases/química , Oxigenases/metabolismo , Calibragem , Eletroquímica , Concentração de Íons de Hidrogênio , Isoenzimas/química , Isoenzimas/metabolismo , Reprodutibilidade dos Testes , Soluções
14.
Nihon Hinyokika Gakkai Zasshi ; 96(6): 623-31, 2005 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-16218405

RESUMO

OBJECTIVE: To assess the significance and current status of the benign prostatic hyperplasia (BPH) impact index (BII) in the evaluation of subjective symptoms of impaired urination in so-called QOL disease, BPH. PATIENTS AND METHODS: Over the past 2 year-period, in 159 patients with the diagnosis of BPH were asked to reply to each of the international prostate symptom score (I-PSS), QOL index and BII questionnaires. The subjective symptom scores (a total of 246 points) were evaluated from the viewpoint of clinical statistics in the search for any these and to find which questions cover the BII, most. RESULTS: 1) Statistically significant but moderate correlations were observed among I-PSS total score, QOL index and BII. The correlations among Qmax, BII and QOL were very weak. 2) Out of the 11 domains in both IPSS and BII, 2 questions of BII ("bothersomeness caused by urinary problems" and "degree of worry about well-being") and 4 questions of IPSS ("residual sense," " pollakisuria," "weak urinary stream" and "nocturia") were shared as QOL indices. Patient satisfaction was affected also by the questions in the BII. 3) Of the 7 BPH symptoms assessed in IPSS, 4 symptoms ("residual sense," "pollakisuria," "weak urinary stream" and "nocturia") affected the QOL index, and 4 symptoms ("urgency on micturition," "residual sense," "nocturia" and "strain at urination") affected BII. 4) Of the 7 symptoms assessed by IPSS, different symptoms affected each of the 4 BII questions. CONCLUSION: It is needed to assess BPH symptoms not only by the IPSS and QOL index but also based on BII to provide the detailed therapeutic instructions and thorough patients consultation.


Assuntos
Hiperplasia Prostática/fisiopatologia , Qualidade de Vida , Transtornos Urinários/fisiopatologia , Idoso , Ansiedade , Humanos , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/psicologia , Perfil de Impacto da Doença , Transtornos Urinários/psicologia
15.
J Neurochem ; 87(5): 1145-51, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14622094

RESUMO

In glutamate-mediated excitatory neuronal cell death, immunosuppressants (FK506, Cys-A) are powerful agents that protect neurons from apoptosis. Immunosuppressants inhibit two types of enzyme, calcium/calmodulin-dependent protein phosphatase (calcineurin: CaN), and peptidyl-prolyl cis-trans-isomerase (PPIase) activity such as the FKBP family. In this study, we used a protein transduction approach to determine the functional role of CaN and to produce a potential therapeutic agent for glutamate-mediated neuronal cell death. We created a novel cell-permeable CaN autoinhibitory peptide using the 11 arginine protein transduction domain. This peptide was highly efficient at transducing into primary culture neurons, potently inhibited CaN phosphatase activities, and inhibited glutamate-mediated neuronal cell death. These results showed that CaN plays an important role in excitatory neuronal cell death and cell-permeable CaN autoinhibitory peptide could be a new drug to protect neurons from excitatory neuronal death.


Assuntos
Apoptose/efeitos dos fármacos , Inibidores de Calcineurina , Inibidores Enzimáticos/farmacologia , Neurônios/efeitos dos fármacos , Proteínas Nucleares , Peptídeos/farmacologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Apoptose/fisiologia , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Membrana Celular/metabolismo , Células Cultivadas , Proteínas de Ligação a DNA/genética , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacocinética , Genes Reporter , Ácido Glutâmico/toxicidade , Proteínas de Fluorescência Verde , Hipocampo/citologia , Proteínas Luminescentes/genética , Fatores de Transcrição NFATC , Neurônios/citologia , Neurônios/metabolismo , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacocinética , Fármacos Neuroprotetores/farmacologia , Peptídeos/metabolismo , Peptídeos/farmacocinética , Regiões Promotoras Genéticas/efeitos dos fármacos , Estrutura Terciária de Proteína/genética , Estrutura Terciária de Proteína/fisiologia , Ratos , Ratos Wistar , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genética
16.
J Biochem ; 132(2): 279-89, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12153727

RESUMO

Hic-5, a member of the paxillin family of adaptor molecules, is localized at focal adhesion and implicated in integrin-mediated signaling. Hic-5 and paxillin exhibit structural homology and share interacting factors, however, diverse functions are suggested for them. In this study, we carried out yeast two-hybrid screening to identify Hic-5 interacting factors using its LD3-4 region, which includes the Hic-5-specific amino acid sequence, as a bait. Through the screening, we identified GIT1, an Arf GTPase-activating protein, as a Hic-5 binding protein. The interaction of these two proteins was mediated by the LD3 motif of Hic-5 and the C-terminal region, which includes a paxillin-binding subdomain, of GIT1. Although GIT1 is known as a paxillin-binding protein, we only observed weak association of paxillin with GIT1 in the overexpression system. In contrast, Hic-5 firmly bound to GIT1 under the same conditions. In addition, the paxillin/GIT1 complex contained PIX, a guanine nucleotide exchange factor, whereas the Hic-5/GIT1 complex contained a smaller amount of PIX. These results suggested that paxillin and Hic-5 associate with GIT1 with different binding modes, and that the Hic-5 complex possesses static features compared with the paxillin complex, which contains both positive and negative regulators of GTPases involved in actin dynamics. Moreover, Hic-5-mediated inhibition of cell spreading was restored by co-expression of the C-terminal fragment of GIT1, which perturbs the interaction of Hic-5 with endogenous GIT1. Thus, it was demonstrated that Hic-5 and GIT1 interact functionally in addition to showing a physical association.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Fosfoproteínas/metabolismo , Células 3T3 , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas de Ciclo Celular/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas com Domínio LIM , Camundongos , Dados de Sequência Molecular , Paxilina , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Troca de Nucleotídeo Guanina Rho , Alinhamento de Sequência , Transdução de Sinais/fisiologia , Técnicas do Sistema de Duplo-Híbrido
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