Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Zhonghua Yi Xue Za Zhi ; 100(22): 1699-1703, 2020 Jun 09.
Artigo em Chinês | MEDLINE | ID: mdl-32536088

RESUMO

Objective: To investigate the novel genetic cause associated with hypospadias and the strategy for preventing offspring genetic defects in these patients. Methods: In March 2019, a patient with gonadal dysplasia (hypospadias associated with cryptorchidism) was referred to Shanghai General Hospital. His secondary sex characters, level of sex hormones and the development of male reproductive system was assessed through physical examination, sex hormone examination, male reproductive system B-ultrasound and computed tomography (CT). Whole-exome sequencing (WES) was preformed to investigate the pathogenic genetic variations associated with hypospadias and cryptorchidism. Also, Sanger sequencing was conducted to verify the WES results in the pedigree. Semen analysis was used to assess the fertility of the proband and the SRD5A2 gene analysis of his spouse was performed to assess the risk of genetic defects in the offspring. Results: The patient suffered from gonadal dysplasia (hypospadias associated with cryptorchidism). Physical examination showed an inverted triangular distribution of pubic hair, small penis and the volume of the testis was 8 ml. Sex hormone examination revealed the level of FSH, LH, Pituitary prolactin (PRL), estrogen (E(2)), testosterone (T), and sex hormone-binding globulin (SHBG) was 25.81 U/L, 10.84 U/L, 21.09 µg/L, 153 pmol/L, 16.95 nmol/L, and 36.15 nmol/L respectively. B-ultrasound and computed tomography (CT) showed left inguinal testis. Also, semen analysis illustrated that the volume was 0.05 ml and sperm concentration<2×10(6)/ml, suggesting oligospermia in this case. WES sequencing and Sanger sequencing showed compound heterozygous LoF mutations in SRD5A2 [NM_000348.3:C.679C>T(p.Arg227Ter) and NM_000348.3:C.16C>T(p.Gln6Ter)] in this patient. And there were no pathogenic genetic variations of SRD5A2 in the spouse. Conclusion: Novel compound heterozygous LoF mutations in SRD5A2[NM_000348.3:C.679C>T(p.Arg227Ter) and NM_000348.3:C.16C>T(p.Gln6Ter)] may be the primary cause of disorders of sex development.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Criptorquidismo , Transtornos do Desenvolvimento Sexual , Proteínas de Membrana/genética , China , Transtornos do Desenvolvimento Sexual/genética , Humanos , Masculino , Mutação , Globulina de Ligação a Hormônio Sexual , Testosterona
2.
Int J Oral Maxillofac Surg ; 48(12): 1533-1541, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31235392

RESUMO

Jaw deviation is frequently seen in Class III patients. The aim of the study was to investigate asymmetric features of skeletal, dental and soft tissues in three types of jaw asymmetry based on our previously reported classification system. The cone-beam computed tomography (CBCT) images of 70 Class III patients were analysed. Group 1 patients showed large shift of menton and synchronous but smaller ramus deviation. The maxillomandibular complex had roll and yaw rotations to the menton-deviation side. Maxillary and dental asymmetry was obvious in transverse and vertical dimensions. Cant of occlusal plane and lip line was apparent. Group 2 patients also exhibited menton and ramus deviation to the same side but the discrepancy in ramus width was larger than menton shift. Asymmetry in Group 2 resulted from a bodily side shift of the maxillomandibular complex without obvious rotation. Group 3 patients had menton and ramus deviated in opposite directions which seemed secondary to a yaw rotation. Double-jaw surgery is generally required for Groups 1 and 3 while Group 2 patients may be successfully treated by mandibular surgery only provided that arch width discrepancy can be managed by orthodontic measures.


Assuntos
Assimetria Facial , Má Oclusão Classe III de Angle , Cefalometria , Tomografia Computadorizada de Feixe Cônico , Humanos , Imageamento Tridimensional , Mandíbula , Maxila
3.
Vox Sang ; 112(7): 671-677, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28836328

RESUMO

BACKGROUND: The band 3 macrocomplex (also known as the ankyrin-associated complex) on the red cell membrane comprises two interacting subcomplexes: a band 3/glycophorin A subcomplex, and a Rh/RhAG subcomplex. Glycophorin B (GPB) is a component of the Rh/RhAG subcomplex that is also structurally associated with glycophorin A (GPA). Expression of glycophorin B-A-B hybrid GP.Mur enhances band 3 expression and is associated with lower levels of Rh-associated glycoprotein (RhAG) and Rh polypeptides. The goal of this study was to determine whether GP.Mur influenced erythroid Rh/RhAG expression at the transcript level. MATERIALS AND METHODS: GP.Mur was serologically determined in healthy participants from Taitung County, Taiwan. RNA was extracted from the reticulocyte-enriched fraction of peripheral blood, followed by reverse transcription and quantitative PCR for RhAG, RhD and RhCcEe. RESULTS: Quantification by real-time PCR revealed significantly fewer RhAG and RhCcEe transcripts in the reticulocytes from subjects with homozygous GYP*Mur. Independent from GYP.Mur, both RhAG and RhD transcript levels were threefold or higher than that of RhCcEe. Also, in GYP.Mur and the control samples alike, direct quantitative associations were observed between the transcript levels of RhAG and RhD, but not between that of RhAG and RhCcEe. CONCLUSION: Erythroid RhD and RhCcEe were differentially expressed at the transcript levels, which could be related to their different degrees of interaction or sensitivity to RhAG. Further, the reduction or absence of glycophorin B in GYP.Mur erythroid cells affected transcript expressions of RhAG and RhCcEe. Thus, GPB and GP.Mur differentially influenced Rh/RhAG expressions prior to protein translation.


Assuntos
Células Eritroides/metabolismo , Glicoforinas/genética , Sistema do Grupo Sanguíneo Rh-Hr/genética , Glicoforinas/sangue , Glicoforinas/metabolismo , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sistema do Grupo Sanguíneo Rh-Hr/sangue , Sistema do Grupo Sanguíneo Rh-Hr/metabolismo , Taiwan
4.
Zhonghua Yi Xue Za Zhi ; 97(16): 1244-1247, 2017 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-28441854

RESUMO

Objective: To analyze the correlation between anatomy of spermatic vessels and varicocele, providing reference for the preoperative assessment and treatment of varicocele. Methods: A total of 156 patients who underwent microsurgical left subinguinal varicocelectomy at Shanghai General Hospital between May 2015 and July 2016 were included in this study. The severity of varicocele and number of spermatic vessels detected in operations were recorded. According to the number of internal spermatic arteries (ISAs), the patients were divided into three groups: single-ISA group (55 cases), double-ISAs group (63 cases) and multi-ISAs group (38 cases), to analyze the correlation among spermatic vessels and to compare varicocele grade, the volume of testes, the parameter of semen analysis, serum reproductive hormone, surgery time, and hospital stay among the three groups. Results: The number of ISAs was positively correlated with the ipsilateral internal spermatic veins (ISVs) (r=0.210; P=0.008)and lymphatic vessels (r=0.224; P=0.005); the number of lymphatic vessels was positively correlated with the ipsilateral gubernacular veins (r=0.172; P=0.032)and ISVs (r=0.296; P=0.000) . The number of ISVs in the multi-ISAs group (10.58±4.28) was significantly larger than that in the single-ISA group (8.22±3.10, P=0.003). The number of lymphatic vessels in the multi-ISAs group(4.11±1.90)was also significantly larger than that in the double-ISA group(3.76±1.40, P=0.020) and the single-ISA group(3.13±1.52, P=0.007). The number of ISVs in grade 2 varicocele patients (9.74±3.90) was significantly higher than that in grade 3 varicocele patients (8.33±3.10, P=0.013). No significant differences in varicocele grade, change of pre- and post-operative semen analysis, serum reproductive hormone, the volume of ipsilateral testes, surgery time, and hospital stay were observed among the three groups. Conclusions: There is a correlation among various kinds of spermatic vessels. Patients with grade 2 varicocele, especially who have multiple ISAs, are likely to have more ISVs and lymphatic vessels. For these patients, surgeons should pay more attention to protect spermatic arteries and lymphatics carefully while ligating varicose veins completely to prevent recurrence and complications.


Assuntos
Cordão Espermático/patologia , Varicocele/patologia , China , Humanos , Masculino , Microcirurgia , Cordão Espermático/irrigação sanguínea , Veias
6.
J Laparoendosc Adv Surg Tech A ; 11(1): 47-51, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11444325

RESUMO

Spilled gallstones left in the abdominal cavity or trapped at trocar sites may cause considerable morbidity. We saw a patient with an abdominal wall abscess 2 years after laparoscopic cholecystectomy secondary to spilled stones. After we reviewed the operative procedure in addition to the accumulated experience in laparoscopic surgery, we believe that retrieval of specimens and their contents is of paramount importance, especially when the gallbladder is infected, contains several stones, or may harbor malignancy. Therefore, we made use of a simple surgical glove with a long pursestring suture surrounding the opening to collect the specimen. This method proved to be simple and quite convenient, with the needed materials readily available. It can collect the spilled stones within the abdominal cavity as well as the gallbladder and can transport these stones out of the abdominal cavity with ease and safety. It also protects the specimen in contact with the wound and cuts short the operating time. The technique and advantages are described.


Assuntos
Abscesso Abdominal/etiologia , Colelitíase/complicações , Abscesso Abdominal/prevenção & controle , Colecistectomia Laparoscópica/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade
7.
Arch Biochem Biophys ; 385(1): 108-16, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11361006

RESUMO

The laminin-binding alpha7beta1 integrin receptor is highly expressed by skeletal and cardiac muscles, and has been suggested to be a crucial molecule during myogenic cell migration and differentiation. Absence of integrin alpha7 subunit contributes to a form of muscular dystrophy in integrin alpha7 null mice, whereas specific mutations in the alpha7 gene are associated in humans with congenital myopathy. To examine in more detail the potential role of integrin alpha7 in human-related muscular disorders, we cloned alpha7 cDNA by RT-PCR from human skeletal muscle mRNA and then expressed the full-length human integrin alpha7 cDNA by transfection in several cell lines including MCF-7, COS-7, and NIH3T3 cells. The isolated cDNA corresponds to the human alpha7X2B alternative splice form. Expression of human alpha7 was further confirmed by transfection of chimeric human/mouse alpha7 cDNA constructs. To demonstrate the functionality of expressed human alpha7, adhesion experiments with transfected MCF-7 cells have confirmed the specific binding of human alpha7 to laminin. In addition, mouse polyclonal and monoclonal antibodies were generated against the extracellular domain of human alpha7 and used to analyze by flow cytometry MCF-7 and NIH3T3 cells transfected with the full-length of human alpha7 cDNA. These results show for the first time the exogenous expression of functional full-length human alpha7 cDNA, as well as the development of monoclonal antibodies against the human alpha7 extracellular domain. Antibodies developed will be useful for further analysis of human disorders involving alpha7 dysfunction and facilitate isolation of muscle stem cells (satellite cells) and thereby expand the opportunities for genetically modified transplantation treatment of human disease.


Assuntos
Antígenos CD/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Cadeias alfa de Integrinas , Laminina/metabolismo , Células 3T3 , Processamento Alternativo , Animais , Anticorpos Monoclonais/metabolismo , Antígenos CD/metabolismo , Biotina/metabolismo , Western Blotting , Células COS , Adesão Celular , Linhagem Celular , Separação Celular , Clonagem Molecular , DNA Complementar/metabolismo , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Camundongos , Dados de Sequência Molecular , Músculo Esquelético/metabolismo , Testes de Precipitina , Estrutura Terciária de Proteína , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Células Tumorais Cultivadas
8.
Exp Cell Res ; 265(2): 212-20, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11302686

RESUMO

Fundamental insights have come from the study of myogenesis. Primary myoblasts isolated directly from muscle tissue more closely approximate myogenesis than established cell lines. However, contamination of primary muscle cultures with nonmyogenic cells can complicate the results. To overcome this problem, we previously described a method for myoblast purification based on novel culture conditions (T. A. Rando and H. M. Blau, 1994, J. Cell Biol. 125, 1275--1287). Here we report a refinement of this method that leads directly to an enriched population of mouse primary myoblasts, within significantly fewer population doublings. The method described here avoids using adhesion as a criterion for selection. This advance capitalizes on the ability of the antibody CA5.5 to recognize alpha 7 integrin, a muscle-specific cell surface antigen. Enrichment of myoblasts to greater than 95% of the cell population can be achieved by a single round of flow cytometry or magnetic bead separation. This is the first description of a mouse myoblast purification method based on a cell-type-specific antigen. The ease of this procedure for isolating primary myoblasts should expand the opportunities for (1) using these cells in cell transplantation studies in animal models of human disease, (2) isolating and characterizing mutant myoblasts from transgenic animals, and (3) allowing in vitro studies of molecules that regulate muscle cell growth, differentiation, and neoplasia.


Assuntos
Anticorpos Monoclonais/metabolismo , Antígenos CD/metabolismo , Separação Celular/métodos , Cadeias alfa de Integrinas , Músculo Esquelético/citologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos CD/imunologia , Células Cultivadas , Fibroblastos/metabolismo , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos C3H , Microscopia de Fluorescência , Especificidade da Espécie
9.
Exp Cell Res ; 262(2): 180-96, 2001 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11139342

RESUMO

During tissue morphogenesis and tumor invasion, epithelial cells must undergo intercellular rearrangement in which cells are repositioned with respect to one another and the surrounding mesenchymal extracellular matrix. Using three-dimensional aggregates of squamous epithelial cells, we show that such intercellular rearrangements can be triggered by activation of beta1 integrins after their ligation with extracellular matrices. On nonadherent substrates, multicellular aggregates (MCAs) formed rapidly via E-cadherin junctional complexes and over time became compacted spheroids exhibiting a more epithelial phenotype. After MCAs were replated on culture substrates, the spheroids collapsed to yield tightly arranged cell monolayers. Cell-cell contact induced rapid elevation in E-cadherin levels, which was due to an increase in the metabolic stability of junctional receptors. During MCA remodeling of cell-cell adhesions, and monolayer formation, their E-cadherin levels fell rapidly. Similar behavior was obtained regardless of which ECM ligand-collagen type I, fibronectin, or laminin 1-MCAs were seeded on. In contrast, when seeded onto a matrix elaborated by squamous epithelial cells, cells in the MCA attached, spread, lost cell-cell junctions, and dispersed. Analysis identified laminin 5 as the active ECM ligand in this matrix, and MCA dispersion required functional beta1 integrin and specifically alpha3beta1. Furthermore, substrate-immobilized anti-integrin antibody effectively reproduced the epithelial-mesenchymal-like transition induced by the laminin 5 matrix. During the early stages of aggregate rearrangement and collapse, cells on laminin 5 substrates, but not those on collagen I substrates, exhibited intense cortical arrays of F-actin, microspikes, and fascin accumulation at their peripheral surfaces. These results suggest that engagement of specific integrin-ligand pairs regulates cadherin junctional adhesions during events common to epithelial morphogenesis and tumor invasion.


Assuntos
Células Epiteliais/metabolismo , Matriz Extracelular/metabolismo , Integrinas/metabolismo , Anticorpos Monoclonais/farmacologia , Caderinas/genética , Caderinas/metabolismo , Proteínas de Transporte/metabolismo , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular/farmacologia , Agregação Celular/fisiologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colágeno/metabolismo , Colágeno/farmacologia , Meios de Cultivo Condicionados/farmacologia , Proteínas do Citoesqueleto/metabolismo , Densitometria , Células Epiteliais/citologia , Fibronectinas/metabolismo , Fibronectinas/farmacologia , Humanos , Citometria por Imagem , Integrina alfa3beta1 , Junções Intercelulares/metabolismo , Laminina/metabolismo , Laminina/farmacologia , Ligantes , Proteínas dos Microfilamentos/metabolismo , Fenótipo , Pseudópodes/metabolismo , RNA Mensageiro/metabolismo , Calinina
10.
Surg Endosc ; 15(2): 217, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12200662

RESUMO

The long-term effect of spilled clips within the abdominal cavity after laparoscopic cholecystectomy is unknown. However, most surgeons agree that the migration of clips has limited clinical consequences. A few cases have been reported of clips that have migrated into the common bile duct, causing stone formation and/or obstructions. We present a case of gallstone pancreatitis treated with laparoscopic cholecystectomy that was complicated by bile leakage from the cystic duct stump 1 day after the procedure. Although the leaking stump sealed itself spontaneously after the placement of a biliary stent, a clip had migrated directly to the superior wall of the first portion of the duodenum. Herein the details of the patient's history are presented. We also discuss the possible mechanisms of clip migration and describe some preventive measures.


Assuntos
Colecistectomia Laparoscópica/instrumentação , Duodeno/lesões , Migração de Corpo Estranho/complicações , Mucosa Intestinal/lesões , Instrumentos Cirúrgicos/efeitos adversos , Bile/fisiologia , Colecistectomia Laparoscópica/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Úlcera/etiologia
11.
Surg Laparosc Endosc Percutan Tech ; 10(4): 243-5, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10961755

RESUMO

Large gastric bezoars are difficult to remove endoscopically. A 78-year-old man presenting with abdominal pain and loss of appetite for 4 months was admitted and evaluated. Gastroscopy disclosed two large phytobezoars within the stomach. Laparoscopic removal was undertaken. The bezoars were removed via a gastrotomy using the three-trocar technique. They were successfully retrieved from the abdominal cavity using an improvised "endobag" made from a simple surgical glove. Such an endobag presents several advantages; they are easy to make, sterile, economical, readily available, disposable, there is ample space to manipulate the specimen within, and there is minimal risk of contamination throughout the procedure. The authors recommend this approach for the treatment of patients with large gastric bezoars in whom laparotomy is indicated.


Assuntos
Bezoares/cirurgia , Laparoscopia , Estômago , Dor Abdominal/etiologia , Idoso , Transtornos da Alimentação e da Ingestão de Alimentos/etiologia , Humanos , Masculino
12.
Surg Laparosc Endosc Percutan Tech ; 10(4): 261-3, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10961760

RESUMO

Laparoscopic surgery has been gaining wide acceptance in recent years. Tissue removal from the abdominal cavity becomes a paramount issue, especially when the specimen is infected, contains several fragments, or potentially contains a malignancy. Several sophisticated instruments and devices have been designed for this purpose. However, most of these are expensive, difficult to handle, and come in a fixed size. Condoms, glove fingers, and zipper-type plastic bags have been tried also, but with limited success. The authors report use of a simple bag made from a surgical glove to collect specimens; a long purse-string suture surrounds the opening or the base of the glove finger to secure material during retrieval. This method has been found to be simple and convenient, and necessary construction material is readily available. The bag not only protects the specimen from contact with the wound but also cuts short the operating time. The technique and advantages are described.


Assuntos
Luvas Cirúrgicas , Laparoscopia , Manejo de Espécimes , Humanos
13.
Surg Laparosc Endosc Percutan Tech ; 9(4): 271-3, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10871175

RESUMO

We conducted a retrospective analysis to assess the feasibility of laparoscopic appendectomy in cases of ruptured appendicitis. Between August 1993 and April 1998, a total of 328 laparoscopic appendectomies were performed in Min-Shen General Hospital. There were 34 cases of pathology-proven ruptured appendicitis. Patients were divided into three groups according to the operative findings: group 1 (10 cases) consisted of patients with a perforated appendix with local peritonitis, group 2 (15 cases) consisted of patients with perforated appendix with diffused peritonitis, and group 3 (9 cases) consisted of patients with abscess formation around the perforated appendix. Three cases in group 3 were converted to laparotomy and were excluded from this study. Mean age (+/- SD) was 30 +/- 15 years in group 1, 39 +/- 23 years in group 2, and 37 +/- 13 years in group 3. Duration of symptoms was longer in group 3 (4.2 +/-1.2 days) than in group 1 (1.8 +/- 1.3 days) and group 2 (2.3 +/- 1.2 days). There was no difference in operation time among groups 1 (52 +/- 10 min), 2 (64 +/- 13 min), and 3 (67 +/- 16 min). The time of flatus passage after operation was similar in the three groups (group 1, 17 +/- 11 hours; group 2, 21 +/- 12 hours; group 3, 24 +/- 8 hours). Hospital stay was significantly shorter in group 1 (3.0 +/- 1.1 days) than in group 2 (5.1 +/- 2.2 days) and group 3 (4.2 +/- 1.2 days). There were no complications and no readmissions. Our results indicate that the laparoscopic approach is feasible for ruptured appendicitis with local or diffuse peritonitis and in selected cases with abscess formation. However, prospective randomized controlled trials are needed to determine which procedure is to be recommended.


Assuntos
Apendicectomia/métodos , Apendicite/cirurgia , Laparoscopia/métodos , Adolescente , Adulto , Idoso , Análise de Variância , Apendicite/diagnóstico , Distribuição de Qui-Quadrado , Feminino , Seguimentos , Humanos , Laparoscopia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Ruptura Espontânea/diagnóstico , Ruptura Espontânea/cirurgia , Resultado do Tratamento
14.
Surg Laparosc Endosc Percutan Tech ; 9(5): 372-4, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10803403

RESUMO

Omental cysts are the least-common variety of all types of intra-abdominal cystic lesions. In the past, transabdominal laparotomy with excision of the cyst was the treatment of choice. With the advent of laparoscopic surgery, it has become possible to resect the cyst without the need for a large incision in the abdomen. We report a case of a 15-year-old girl who underwent diagnostic laparoscopy for recurring abdominal pain of 2 years' duration. The procedure revealed a huge cyst lying above the omentum with its pedicle rising from the greater curvature of the stomach. The pedicle was noted to have twisted eight times in a clockwise direction. The cyst was resected by laparoscopic means using three trocars. The postoperative course was uneventful. As presented in this case, we believe that a laparoscopic approach is an attractive alternative for the management of omental cystic lesions.


Assuntos
Cistos/cirurgia , Omento , Doenças Peritoneais/cirurgia , Dor Abdominal/etiologia , Adolescente , Cistos/complicações , Feminino , Humanos , Laparoscopia , Doenças Peritoneais/complicações , Anormalidade Torcional
15.
J Cell Sci ; 110 ( Pt 13): 1477-87, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9224765

RESUMO

Expression of the alpha7 integrin is developmentally regulated and is thought to be tissue-specific for both skeletal and cardiac muscles. We now report that alpha7 is also strongly and ubiquitously expressed by various types of smooth muscle, including vascular, gastrointestinal and genitourinary smooth muscles. In addition, alpha7 was surface-expressed by a number of smooth muscle cell lines that maintained their differentiated phenotype following adaptation to culture. Studies with the mouse 9E11G smooth muscle cell line showed that the alpha7 integrin mediated both adhesion and motility of these cells on laminin 1 substrates. Alpha7 expression appears to correlate with the smooth-muscle-differentiated phenotype. The multipotential P19 mouse embryonic stem cell line lacks alpha7 but uses the alpha6 integrin to adhere to laminin 1. Following retinoic acid-induced P19 differentiation predominantly to the smooth muscle cell lineage, high expression of alpha7 was detected along with partial dependence on alpha7 for binding to laminin. The expression of alpha7 paralleled the induction of smooth-muscle-specific alpha-actin, as revealed by dual-labeling flow cytometry. In contrast, alpha7, which initially was highly expressed on the surface of vascular smooth muscle cell explants, was rapidly downregulated in smooth muscle cell outgrowths as they dedifferentiated into their synthetic phenotype. The results indicate that the expression of alpha7 integrin in smooth muscle cells is associated with their differentiated phenotype and mediates their interaction with laminins.


Assuntos
Antígenos CD/metabolismo , Cadeias alfa de Integrinas , Músculo Liso/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos , Antígenos CD/genética , Antígenos CD/imunologia , Adesão Celular , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular , Imuno-Histoquímica , Laminina/metabolismo , Camundongos , Dados de Sequência Molecular , Músculo Liso/citologia , Músculo Liso/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Peptídeos/genética , Peptídeos/imunologia , Fenótipo , Ratos , Receptores de Laminina/metabolismo , Tretinoína/farmacologia
16.
J Biol Chem ; 271(41): 25598-603, 1996 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-8810334

RESUMO

The laminin-binding alpha7beta1 integrin receptor is expressed at high levels by skeletal and cardiac muscles and by certain melanocytic cells. We have assessed the potential role of the alpha7A/B integrin isoforms in mediating cell adhesion and motility and determined the laminin isoform specificity of this integrin. When MCF-7 breast carcinoma cells, normally nonadherent to laminin 1, were stably transfected with cDNA for mouse alpha7, they adhered with high efficiency and migrated on laminin 1 substrates. Function-perturbing monoclonal antibodies generated to mouse alpha7 subunit blocked both adhesion and migration of alpha7 transfectants on laminin 1 substrates. Additional studies with MCF-7 transfectants revealed that alpha7beta1 binds well to laminin 1 and to a mixture of laminin 2 and 4 but not to laminin 5. Importantly, alpha7beta1 was capable of promoting motility on both laminin 1 and laminin 2/4 substrates. However, MCF-7 cells transfected with cDNA for either alpha7A or alpha7B showed no significant differences in cell adhesion or motility on laminin 1 substrates. Although the role for the alternatively spliced cytoplasmic variants of alpha7 remains unknown, the results establish that alpha7beta1 mediates cell adhesive activities on a restricted number of laminin isoforms.


Assuntos
Antígenos CD/fisiologia , Adesão Celular , Cadeias alfa de Integrinas , Laminina , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/farmacologia , Antígenos CD/biossíntese , Antígenos CD/química , Sequência de Bases , Neoplasias da Mama , Linhagem Celular , Movimento Celular , Primers do DNA , Feminino , Humanos , Integrinas/fisiologia , Cinética , Camundongos , Dados de Sequência Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Transfecção
17.
Cancer Metastasis Rev ; 14(3): 205-17, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8548869

RESUMO

Cell motility, a primary component of tumor cell invasion, is a continuum of sequential events in which the cell extends pseudopodia, forms nascent attachments, assembles and contracts the cytoskeleton, and finally, as it translocates forward, disengages distal adhesions. What triggers cells to move? Substratum contact mediated by integrin adhesion receptors is important, but other signals such as chemokinetic factors appear to be required for continued crawling. It is now apparent that integrins do not simply bind cells to matrix in a Velcro-like fashion, but also are potent signaling molecules. Initial engagement of integrins induces their condensation into focal contacts, forming anchors to the extracellular matrix and discrete signal-transducing complexes on the cytoplasmic surface. A number of growth factors, through either autocrine or paracrine pathways, can activate the cellular machinery that mobilizes the cell. Thus, these two classes of receptors--the integrin receptors that bind specific extracellular adhesion molecules, and growth factor receptors that bind their respective ligands--can regulate cell locomotion. Not surprisingly, there is 'cross-talk' between integrin and growth factor receptors that occurs through their common intracellular signaling pathways. In this way, each receptor type can either amplify or attenuate the other's signal and downstream response. An example of growth factor-induced motility is the epithelial-mesenchymal transition induced by hepatocyte growth factor/scatter factor (HGF/SF). When bound to its receptor, the c-met proto-oncogene product, HGF/SF induces a phenotypic conversion that appears to be an important aspect of tumor progression in malignant carcinomas. The motogenic response produced by HGF/SF in carcinoma cells occurs in discrete steps in which integrins and focal adhesion kinase (p125FAK) are first recruited to focal contacts. This is rapidly followed by cell spreading, disruption of focal adhesions and cell-cell contacts, and, finally, cell crawling. The precise mechanism by which growth factors such as HGF/SF and its receptor induce this motogenic response and modulate integrin function has not been clearly defined but appears to involve several signaling pathways. Understanding the process by which growth factor and integrin receptors interact and regulate motility may suggest novel targets for therapeutic intervention.


Assuntos
Movimento Celular/fisiologia , Substâncias de Crescimento/fisiologia , Integrinas/fisiologia , Animais , Matriz Extracelular/fisiologia , Humanos , Invasividade Neoplásica , Proto-Oncogene Mas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA