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1.
Skin Res Technol ; 22(2): 152-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26058484

RESUMO

BACKGROUND/PURPOSE: Facial skin must be linked to underlying structures to maintain facial morphology and prevent sagging, but the mechanism of facial skin retention is largely unknown. We aimed to elucidate this mechanism. METHODS: Twenty-two cheek skin specimens (age range: 10s-60s, both genders) were observed histologically. And 30 cheek of healthy Japanese volunteers (age range: 30s-50s, female) was photographed and the severity of sagging was graded. Dermal layer morphology was observed non-invasively with ultrasound. Skin-retaining force was measured with a Cutometer MPA 580(®) , and sagging severity was evaluated by grading criteria. RESULTS: Histological observation revealed characteristic convex structures at the bottom of the dermal layer. Non-invasive study showed that the depth of the convex structures, measured by ultrasonography, was significantly negatively related to the ratio of viscoelastic to elastic distention (Uv/Ue) and positively related to the ratio of elastic recovery to total deformation (Ur/Uf) at the cheek of female volunteers, measured by cutometer. It was also negatively related to sagging severity. Further, Ur/Uf was negatively and Uv/Ue was positively related to sagging severity. CONCLUSION: Characteristic convex structures at the bottom of the dermal layer serve as anchoring structures to maintain skin morphology.


Assuntos
Bochecha/patologia , Bochecha/fisiologia , Derme/patologia , Derme/fisiologia , Envelhecimento da Pele/patologia , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Criança , Derme/diagnóstico por imagem , Módulo de Elasticidade/fisiologia , Humanos , Pessoa de Meia-Idade , Propriedades de Superfície , Adulto Jovem
2.
Skin Res Technol ; 15(3): 299-305, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19624426

RESUMO

BACKGROUND/PURPOSE: Facial sagging is associated with aging, although the mechanism remains unclear. The aim of this study was to investigate the mechanism of facial sagging by examining the relationship of sagging severity to changes of skin elasticity, fat mass and facial muscle function at the cheek. METHODS: Faces of 108 healthy Japanese female volunteers, aged 20-60 years were photographed at an angle of 45 degrees . Standard scores of sagging severity were established by analyzing the photographs. We examined the correlations of scored sagging levels with skin elasticity measured with a Cutometer MPA 580, fat content estimated by bioelectrical impedance analysis and facial muscle function (lip sealing force and occlusal force) in middle-aged female volunteers (30-40 years) with a wide range of sagging scores. RESULTS: Because the upper, lower and lateral areas in the cheek may show severe sagging, a six-grade score of sagging severity was separately established for each area. Each score was significantly correlated positively with age (20-60 years). In middle-aged volunteers, the sagging scores in all three areas of the cheek were significantly and negatively associated with skin elasticity. Body fat percentage was significantly and positively correlated with the sagging scores in the lower and lateral areas, although the correlation was only weakly positive in the upper area. Mimetic muscle function, measured in terms of lip sealing pressure, was significantly and negatively correlated with the sagging score only at the upper area of the cheek, but masticatory muscle function, measured in terms of occlusal force pressure, was not associated with the sagging score. CONCLUSIONS: Sagging may be associated with the reduction of skin elasticity and mimetic muscle function and increase of fat mass, but the relationships are different in different areas of the cheek.


Assuntos
Tecido Adiposo/fisiologia , Envelhecimento/fisiologia , Bochecha/fisiologia , Músculo Esquelético/fisiologia , Envelhecimento da Pele/fisiologia , Adolescente , Adulto , Envelhecimento/patologia , Biomimética/métodos , Bochecha/anatomia & histologia , Módulo de Elasticidade/fisiologia , Feminino , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/anatomia & histologia , Tamanho do Órgão/fisiologia , Pele/anatomia & histologia , Adulto Jovem
3.
FEBS Lett ; 433(1-2): 41-3, 1998 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-9738929

RESUMO

The deduced amino acid sequences of 72-kDa beta-1,3-glucanase from Bacillus circulans WL-12 (GIcA) and 91-kDa enzyme from B. circulans IAM1165 (BglH) are highly homologous, except that the latter has an additional long C-terminal region composed of 192 amino acid residues. Two mutant enzymes (BgIH deprived of the C-terminal region and GIcA with the C-terminal region added) were constructed. The enzymes possessing the C-terminal region bound more abundantly to pachyman (insoluble beta-1,3-glucan) and A.spergillus oryzae cell wall than those not possessing the region. This indicates that the C-terminal region participated in binding of the enzymes to insoluble beta-1,3-glucan.


Assuntos
Bacillus/enzimologia , Glucanos/metabolismo , Fragmentos de Peptídeos/química , beta-Glucanas , beta-Glucosidase/química , beta-Glucosidase/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Escherichia coli/genética , Glucana 1,3-beta-Glucosidase , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Fragmentos de Peptídeos/metabolismo , Proteínas Recombinantes , Sequências Repetitivas de Ácido Nucleico , Homologia de Sequência , Solubilidade , Relação Estrutura-Atividade , Temperatura
4.
Biochem Pharmacol ; 62(3): 335-40, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11434906

RESUMO

The action and the effect of the newly synthesized compounds 4GBE43 [N-(1,2-diethyltetrahydro-1H-pyrazol-4-yl)-4-[(2E)-3,7-diethyl-2,6-octadienyl] oxybenzamide] and 2BBE43 [2-(benzyloxy)-N-(1,2-diethyltetrahydro-1H-pyrazol-4-yl)benzamide] against lipid peroxidation were studied. 4GBE43 and 2BBE43 quenched the ESR signal of diphenylpicrylhydrazyl (DPPH), suggesting that 4GBE43 and 2BBE43 act as scavengers of free radicals and that each compound quenched 6 free radical molecules. These compounds suppressed the oxidation of methyl linoleate emulsions and soybean phosphatidylcholine liposomes by a free radical initiator, suggesting that these compounds quench the lipid peroxyl radical. 4GBE43 and 2BBE43 also suppressed the spontaneous oxidation of rat brain homogenates. The inhibitory effect of 2BBE43 was of the same order of magnitude (IC50) as that of probucol. The IC50 of 4GBE43 was on the same order of magnitude as that of alpha-tocopherol. However, 4GBE43 at 10(-4)-10(-5) M completely inhibited peroxidation, showing it to be more effective than alpha-tocopherol. These results suggest that 4GBE43 and 2BBE43 act as antioxidants by quenching the lipid peroxyl radical.


Assuntos
Antioxidantes/farmacologia , Benzamidas/farmacologia , Encéfalo/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Pirazóis/farmacologia , Animais , Encéfalo/metabolismo , Técnicas In Vitro , Ácidos Linoleicos/metabolismo , Lipossomos/metabolismo , Oxirredução/efeitos dos fármacos , Ratos
5.
J Pharm Pharmacol ; 50(10): 1173-7, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9821666

RESUMO

The effects of simultaneous administration of some dyadic combinations of antioxidants or vitamins and related agents on cellular proliferation of mouse leukaemia L5178Y cells in-vitro have been examined experimentally. The data were analysed on the basis of the concept of independence for evaluation of interactions between biologically active agents. An approach for evaluation of the synergism or antagonism of the action of two agents is proposed in which the types and extents of interactions are described by response-surface diagrams. The combinations phytol with trans-retinol, abscisic acid with trans-retinol, and menadione with sodium L-ascorbate were synergistic, whereas menadione with trans-retinol, and plumbagin with trans-retinol were antagonistic in the dose-range tested. These results reveal that the interactions between two agents depend not only on the combinations of agents but also on the dose ranges or the ratios of agents under the experimental domain studied.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Leucemia L5178/genética , Leucemia L5178/metabolismo , Ácido Abscísico/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Camundongos , Tretinoína/farmacologia , Células Tumorais Cultivadas , Vitamina K/farmacologia
6.
J Pharm Pharmacol ; 52(2): 243-51, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10714957

RESUMO

Procaine has been used to stimulate plant growth and it has been noted that it also promotes growth of microorganisms. The effect of procaine hydrochloride concentration on the growth rates of several species of microalgae and cyanobacteria was studied under both photoautotropic and heterotrophic growth conditions. Procaine hydrochloride was added to cultures at concentrations over the range 0.01-1000 mg L(-1). A stimulating effect of procaine hydrochloride on photoautotrophic growth was observed for the cyanobacteria Anabaena cylindrica and Anabaena variabilis, and for the salt-tolerant green algae Dunaliella primolecta and Dunaliella parva. During active growth in batch culture an increase in growth rate (compared with control culture without procaine hydrochloride) of about 25% was observed at 0.1 mgL(-1) of procaine hydrochloride for A. cylindrica. However, procaine hydrochloride was toxic at concentrations of > 10 mgL(-1). Simultaneous administration of hydrolysis products of procaine, p-aminobenzoic acid and diethyl aminoethanol, in lieu of procaine hydrochloride, was as effective as procaine in stimulating growth of A. cylindrica. Heterotrophic growth of Chlorella ellipsoidea and Prototheca zopfii was not stimulated by procaine hydrochloride over the concentration range studied (0.1-10 mg L(-1)). The combined effects of procaine hydrochloride concentration and four other environmental factors (temperature, light intensity, CO2 concentration in the flushing gas and NaCl concentration) on growth rate of D. primolecta was modelled using both a neural network approach and a response surface method. These results indicate that procaine hydrochloride exerts different effects on the growth of microalgal and cyanobacterial cells as functions of dosage, species and culture conditions.


Assuntos
Anestésicos Locais/farmacologia , Cianobactérias/efeitos dos fármacos , Eucariotos/efeitos dos fármacos , Procaína/farmacologia , Cianobactérias/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Meio Ambiente , Eucariotos/crescimento & desenvolvimento , Modelos Teóricos
8.
Cytokine ; 12(6): 727-30, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10843753

RESUMO

The effect of IL-6 on the growth of mouse biliary epithelial cells (BEC), in vitro, was tested by comparing BEC obtained IL-6-deficient mice (IL-6(-/-)) to wild-type littermate controls (IL-6(+/+)), in two different media: simple serum-free media (S-SFM), and complete serum-free media (C-SFM) containing forskolin, which stimulates BEC IL-6 production. In S-SFM, neither IL-6(+/+)nor IL-6(-/-)BEC constitutively produced IL-6 mRNA or protein, and there was no difference between IL-6(+/+)and IL-6(-/-)BEC growth. In contrast, when the BEC were maintained in C-SFM, over 48 h, the growth of IL-6(+/+)BEC was 40% greater than IL-6(-/-)BEC (P<0.006). Enhanced IL-6(+/+)BEC growth in C-SFM was associated with induced expression of IL-6 mRNA and IL-6 protein secretion into the medium, upregulation of the IL-6Ralpha (gp80) and phosphorylation of the signal transducing molecule gp130. In C-SFM, anti-IL-6 neutralizing antibodies blocked enhanced IL-6(+/+)BEC growth, whereas exogenous rhIL-6 stimulated retarded growth of IL-6(-/-)BEC. Thus, under conditions that mimic an inflammatory or stressful microenvironment in vivo, BEC produce, secrete and respond to IL-6, via upregulation and activation of the IL-6Ralpha (gp80)/gp130 signaling system in an autocrine/paracrine manner.


Assuntos
Células Epiteliais/fisiologia , Vesícula Biliar/fisiologia , Interleucina-6/fisiologia , Transdução de Sinais/fisiologia , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Meios de Cultura , Meios de Cultura Livres de Soro , Células Epiteliais/citologia , Vesícula Biliar/citologia , Humanos , Interleucina-6/deficiência , Interleucina-6/genética , Interleucina-6/farmacologia , Camundongos , Camundongos Knockout , Fosforilação , Receptores de Interleucina-6/fisiologia , Proteínas Recombinantes/farmacologia , Transcrição Gênica
9.
Cytokine ; 9(1): 53-8, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9067096

RESUMO

In previous reports, the authors demonstrated that M-CSF was produced by primary-cultured non-parenchymal (NPLC) and parenchymal (PLC) liver cells. In order to clarify the biological role of M-CSF produced by the liver, macrophage colony-stimulating factor (M-CSF)-producing cells in vivo were investigated using reverse transcriptase polymerase chain reaction (RT-PCR), dot blot analysis, in situ hybridization and immunohistochemistry. M-CSF mRNA was constantly identified by RT-PCR in the liver, NPLC and PLC, before and after partial hepatectomy. Dot blot analysis showed that fluctuations of M-CSF mRNA level after partial hepatectomy were not statistically significant. In situ hybridization revealed that M-CSF mRNA was expressed mainly in NPLC and vascular endothelial cells (VEC). In addition, a small number of PLC also expressed M-CSF mRNA. Neither the distribution nor the frequency of M-CSF mRNA positive cells in regenerative livers differed significantly from normal livers. M-CSF immunoreactivity was present in NPLC and VEC at all the times before and after partial hepatectomy, while PLC exhibited M-CSF immunostaining 0.5 days after partial hepatectomy. As normal liver expressed M-CSF mRNA to the same degree as regenerative liver, hepatic M-CSF mRNA production in vivo may be related to the physiological function of the liver. However, transient expression of M-CSF protein in PLC at an early stage after partial hepatectomy may be associated with liver regeneration.


Assuntos
Fígado/metabolismo , Fator Estimulador de Colônias de Macrófagos/biossíntese , Animais , Feminino , Hepatectomia , Immunoblotting , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase/métodos , Transcrição Gênica
10.
Hepatology ; 32(2): 256-67, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10915732

RESUMO

Liver hematopoietic progenitor cells (LHPC) and liver epithelial progenitor cells (LEPC) share a remarkable number of growth and differentiation-controlling receptor-ligand signaling systems. These likely account for the ability of the liver to support hematopoiesis in fetal life, and possibly for suggestions that LHPC can differentiate into hepatocytes. In these experiments, the kinetics and magnitude of LHPC and LEPC activation and expansion were studied by using a concanavalin A (Con A) liver injury model followed by partial hepatectomy (PH). Studies were performed in interleukin 6-deficient (IL-6(-/-)) mice and wild-type (IL-6(+/+)) controls, which show equal susceptibility to Con A- induced injury, because IL-6/gp130 signaling has been implicated in both LHPC and LEPC expansion. Con A pretreatment primed LHPC and LEPC for a rapid and parallel expansion after PH in IL-6(+/+) mice, which was significantly blunted and delayed in the IL-6(-/-) mice. Exogenous IL-6 given immediately before PH after Con A, augmented both LHPC and LEPC expansion in the IL-6(-/-) mice. Thus, the proinflammatory cytokine IL-6, commonly produced in liver injury and inflammatory disease, is an important growth factor involved in the expansion of LHPC and LEPC. This observation has implications for both hepatic carcinogenesis and transplantation.


Assuntos
Concanavalina A/farmacologia , Hematopoese/efeitos dos fármacos , Regeneração Hepática/efeitos dos fármacos , Fígado/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Animais , Células Epiteliais/efeitos dos fármacos , Feminino , Hepatectomia , Interleucina-6/sangue , Interleucina-6/genética , Interleucina-6/fisiologia , Fígado/patologia , Camundongos , RNA Mensageiro/análise , Receptores de Interleucina-6/análise , Células-Tronco/fisiologia
11.
Am J Pathol ; 156(5): 1627-39, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10793074

RESUMO

In an effort to understand the role of IL-6/gp130 signaling in chronic liver injury, IL-6 deficient (IL-6(-/-)) and wild-type control (IL-6(+/+)) mice were subjected to bile duct ligation (BDL) for 12 weeks. This maneuver causes chronic biomechanical stress and liver injury, fueling sustained biliary epithelial and hepatocyte proliferation. By 12 weeks after BDL, IL-6(-/-) mice develop significantly higher total serum bilirubin levels (23.2 +/- 2.3 versus 14.9 +/- 2.1 mg/dl, P < 0.0001; delta bilirubin subfraction 16.7 +/- 4.0% versus 9.2 +/- 1.8%; P < 0.002), and the majority (15/18) show "black" gallbladder bile, compared to IL-6(+/+) mice (5/16; P < 0.003). The IL-6(-/-) mice also cannot sustain the compensatory liver mass increase commonly seen with chronic obstructive cholangiopathy, because of less hepatocyte proliferation, despite a rate of hepatocyte apoptosis similar to that of IL-6(+/+) mice. Moreover, IL-6(-/-) mice show a more advanced stage of biliary fibrosis and a higher mortality rate than the IL-6(+/+) controls (51% versus 23%; P < 0.02). These phenotypic changes in the IL-6(-/-) mice are associated with decreased expression and phosphorylation of gp130 and the transcription factor STAT3, compared to IL-6(+/+) mice. Daily treatment with exogenous recombinant IL-6 for 3-6 weeks starting at 6 weeks after BDL significantly lowers the serum total bilirubin in both groups. In the IL-6(-/-) mice, exogenous IL-6 treatment also increases the level of gp130 protein expression and completely reverses the loss of liver mass by increasing the hepatocyte proliferation. In conclusion, IL-6 appears to contribute to biliary tree integrity and maintenance of hepatocyte mass during chronic injury.


Assuntos
Interleucina-6/deficiência , Cirrose Hepática Biliar/patologia , Alanina Transaminase/sangue , Animais , Antígenos CD/efeitos dos fármacos , Antígenos CD/metabolismo , Apoptose , Bile/química , Ductos Biliares/cirurgia , Bilirrubina/sangue , Peso Corporal , Divisão Celular , Receptor gp130 de Citocina , Marcação In Situ das Extremidades Cortadas , Interleucina-6/genética , Interleucina-6/farmacologia , Ligadura/efeitos adversos , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Biliar/etiologia , Cirrose Hepática Biliar/mortalidade , Masculino , Glicoproteínas de Membrana/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Mutantes , Tamanho do Órgão , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida
12.
Liver ; 20(2): 114-24, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10847479

RESUMO

AIM: The hypothesis that interleukin-6-IL-6/gp130 signaling is involved in liver and biliary epithelial cell (BEC) biology and growth control was tested by subjecting homozygous IL-6 deficient mice (IL-6-/-) and wild type (IL-6+/+) littermate controls to bile duct ligation (BDL). MATERIALS AND METHODS: During the first week after BDL, the two groups were compared with respect to routine liver injury tests, liver histology, BEC and hepatocyte DNA synthesis, together with the expression of mRNA and protein of IL-6 as well as related growth factors, and their receptors. RESULTS: During the first week after BDL, there was marked upregulation of IL-6 mRNA and protein in the IL-6+/+ mice only in the vicinity of the biliary tree; whereas, biliary/peri-biliary IL-6R, HGF and met mRNA and protein increased in both groups. IL-6, HGF mRNA and protein localized to periductal inflammatory cells and stellate cells, while met and IL-6R protein were upregulated in the BEC and, to a lesser extent, in hepatocytes. This occurred during maximal proliferation of the BEC. Despite the absence of IL-6 in the IL-6-/- mice, there were only mildly phenotypic differences between the two groups, and no differences in mortality. Compared to IL-6+/+ controls, IL-6-/- mice showed slightly less BEC proliferation, a trend toward more liver injury, and significantly higher total serum bilirubin (TB) levels, suggestive of impaired biliary tree integrity. These changes were associated with slightly less HGF mRNA and protein expression in the IL-6-/- mice, but the differences were not significant. Leukemia inhibitory factor (LIF), another gp-130 ligand, also showed marked peri-biliary upregulation after BDL in both groups, and also induced BEC DNA synthesis, in vitro. CONCLUSIONS: The mild phenotypical differences between IL-6+/+ and IL-6-/- mice in the acute response to BDL is most likely attributable to the redundancy of the gp-130 signaling system. However, the long-term response to BDL results in a distinct phenotype in the IL-6-/- mice, marked by a relentless rise in serum total bilirubin and an inability to maintain compensatory increase in liver mass.


Assuntos
Colestase Extra-Hepática/metabolismo , Inibidores do Crescimento/metabolismo , Interleucina-6/deficiência , Linfocinas/metabolismo , Morfolinas/metabolismo , Doença Aguda , Alanina Transaminase/sangue , Animais , Ductos Biliares Intra-Hepáticos/citologia , Ductos Biliares Intra-Hepáticos/metabolismo , Bilirrubina/sangue , Células Cultivadas , Colestase Extra-Hepática/patologia , DNA/biossíntese , Primers do DNA/química , Replicação do DNA/fisiologia , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Inibidores do Crescimento/genética , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Técnicas Imunoenzimáticas , Interleucina-6/genética , Fator Inibidor de Leucemia , Fígado/citologia , Fígado/metabolismo , Linfocinas/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/metabolismo , Transdução de Sinais , Regulação para Cima
13.
Hepatology ; 32(1): 26-35, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10869285

RESUMO

A well characterized human cholangiocarcinoma (CC) cell line, SG231, was compared with primary cultures of normal human biliary epithelial cells (BECs) for alterations in interleukin 6 (IL-6) and hepatocyte growth factor (HGF)-mediated stimulation and transforming growth factor beta1 (TGF-beta1) and activin A-mediated inhibition of growth. Results were compared with immunolabeling of the original tumor and after injection of SG231 into the liver of BALB/cByJ-scid mice. In vitro, both BECs and CCs expressed met, gp80, and gp130 messenger RNA (mRNA) and protein, but the levels of expression were higher in the CCs than in the BECs. In both the CCs and BECs, exogenous HGF or IL-6 induced phosphorylation of met or gp130, respectively, and a concentration-dependent increase in DNA synthesis. However, the CCs but not BECs, continued to grow in basal serum-free medium (SFM) and spontaneously produced both IL-6 and HGF under these conditions, which resulted in auto-phosphorylation of gp130 and met, respectively; and neutralizing anti-HGF or anti-IL-6 alone inhibited CC growth, indicative of autocrine growth control circuits. Conversely, activin A inhibits the growth of both BECs and CCs, but does not significantly increase apoptosis. Activin-A-induced growth inhibition of both CCs and BECs can be reversed by 100 ng/mL exogenous IL-6, but not by 10 to 100 ng/mL HGF. TGF-beta1 inhibited the growth of BECs but had no mitoinhibitory or proapoptotic effects on CCs. Immunolabeling of the original tumor and after inoculation into scid mice showed positive staining for met, gp130, gp80, and IL-6. This study contributes to a further understanding of BEC growth control and derangements that can occur during cholangiocarcinogenesis.


Assuntos
Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos , Ductos Biliares/citologia , Colangiocarcinoma/patologia , Fator de Crescimento de Hepatócito/farmacologia , Inibinas/farmacologia , Interleucina-6/farmacologia , Ativinas , Animais , Divisão Celular/efeitos dos fármacos , Fator de Crescimento de Hepatócito/genética , Humanos , Interleucina-6/análise , Interleucina-6/genética , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas c-met/análise , RNA Mensageiro/análise , Fator de Crescimento Transformador beta/farmacologia , Células Tumorais Cultivadas
14.
Hepatology ; 28(5): 1260-8, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9794910

RESUMO

The interleukin-6 (IL-6)/gp-80 and hepatocyte growth factor (HGF)/met ligand/receptor systems have been shown to stimulate biliary epithelial cell (BEC) DNA synthesis in vitro. The mRNA and protein production of these two in vitro mitogens were mapped in vivo during the first week after bile duct ligation (BDL) when peak BEC DNA synthesis is seen. Changes around the biliary tree were compared with those seen in the peripheral liver using a combination of Northern blotting and a unique biliary tree isolation technique, in which the bile ducts and the surrounding portal stroma and inflammatory cells are separated from the hepatocytes by perfusion digestion. Further localization was performed with in situ hybridization and immunohistochemistry. In the normal liver, there is low-level expression of HGF mRNA by periportal stellate cells, and HGF protein localizes to these cells and to neutrophils; extracellular HGF protein is present in the bile. There is no detectable IL-6 mRNA by Northern analysis or IL-6 protein expression in the normal liver, but both met and IL-6 receptor (IL-6R) mRNA are detectable; met mRNA is expressed strongly in the biliary tree, and met protein is expressed weakly on hepatocytes and strongly on BEC. IL-6R mRNA is weakly expressed in the biliary tree, and IL-6R protein is detectable on hepatocytes, with a periportal-to-perivenular gradient, but not on BEC. During the first 3 days after BDL, HGF mRNA expression is increased in both the biliary tree and in the peripheral liver, and production is localized to stellate cells, periductal neutrophils, and stromal cells, which typically accompany the proliferating ductules. IL-6 mRNA and protein were detected only near the biliary tree after BDL, and not in the peripheral liver, and the production was localized to periductal hematolymphoid cells, which had the morphological appearance of macrophages and/or dendritic cells. There is also a distinct up-regulation of met and gp-80 mRNA and protein in the biliary tree, which is stronger than that seen in the peripheral liver. Met protein expression is increased, and IL-6R(gp-80) protein is induced on the proliferating BEC, consistent with the participation of both the HGF/met and IL-6/gp-80 systems in the early phases of type I ductular reactions. These observations show that periductal hematolymphoid and stromal cells are the source of BEC growth factors, and receptors for these factors are up-regulated on BEC during active ductular proliferation. Complex interactions between the inflammatory, stromal, and BEC results in a dysmorphogenic repair response that eventually leads to cirrhosis.


Assuntos
Ductos Biliares/metabolismo , Colangite/metabolismo , Fator de Crescimento de Hepatócito/metabolismo , Interleucina-6/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores de Interleucina-6/metabolismo , Animais , Ductos Biliares/patologia , Ductos Biliares/cirurgia , Divisão Celular , Colangite/patologia , DNA/biossíntese , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Expressão Gênica , Fator de Crescimento de Hepatócito/genética , Interleucina-6/genética , Ligadura , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Proteínas Proto-Oncogênicas c-met/genética , RNA Mensageiro/análise , Receptores de Interleucina-6/genética , Células Estromais/fisiologia
15.
Hepatology ; 29(2): 403-11, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9918916

RESUMO

Recently, it was shown that hepatocyte DNA synthesis after partial hepatectomy (PH) is impaired in interleukin-6-deficient (IL-6(-/-)) mice, which results in significantly delayed, but eventual, recovery of normal liver weight, compared with the IL-6(+/+) controls. Four possible compensatory mechanisms might explain this phenomenon: 1) hepatocyte hypertrophy; 2) activation of the oval cell compartment and subsequent maturation to hepatocytes; 3) non-oval biliary epithelial cell (BEC) proliferation; and/or 4) differential rates of apoptotic cell death in the regenerating liver. These hypotheses were tested by subjecting IL-6(-/-) and IL-6(+/+) mice to PH and determining sequential liver weight, histology, hepatocyte and BEC 5'-bromo-2'-deoxyuridine (BrdU) labeling, liver DNA content, alpha-fetoprotein (AFP) mRNA production, and apoptosis at several time points after PH. Consistent with previous studies, we show that the absence of IL-6 significantly impairs hepatocyte DNA synthesis and delays liver weight recovery after PH, but the defect observed in this study is less severe than that previously reported, and no excess mortality, massive necrosis on histology, nor differences in liver injury test are seen. Interestingly, the IL-6(-/-) mice show more hepatocyte BrdU pulse labeling than the IL-6(+/+) controls at 24 hours, but less at 36, 48, and 60 hours. Continuous BrdU infusion up to 60 hours after PH showed a cumulative hepatocyte labeling index of 79.5% in IL-6(+/+) mice and 70.8% in IL-6(-/-) mice, respectively (P <.03). However, despite a lower labeling index and significantly delayed weight recovery, hepatic mass was equally restored in the two groups by 96 hours. There was no evidence of oval cell proliferation in the IL-6(-/-) mice, as determined by routine histology and AFP mRNA analysis, and non-oval BEC proliferation was also slightly impaired in the IL-6(-/-) mice compared with the IL-6(+/+) mice. In addition, liver DNA content per gram of liver showed an increase compared with normal at 60 hours in both groups, but by 96 hours, there was no difference between the two groups. Thus, neither oval cell nor BEC proliferation, nor hepatocyte hypertrophy, could account for the eventual equivalent weight recovery. There was, however, a difference between the two groups in the rate of apoptosis. In normal livers of both IL-6(-/-) and IL-6(+/+) mice, apoptotic cells were uncommon, and even fewer such cells were detected at 24, 36, and 48 hours after PH. Between 60 and 96 hours after PH, a wave of apoptosis spread through the livers of both groups. The number of apoptotic cells was directly proportional to the magnitude of hepatocyte BrdU labeling and liver DNA content after PH, and the difference between the nadir of apoptosis at 24 hours and the peak at 96 hours was greater for the IL-6(+/+) mice. In addition, a direct comparison between the two groups at 96 hours showed that hepatocyte apoptosis was significantly lower in the IL-6(-/-) versus the IL-6(+/+) mice (P <. 02). Treatment of the IL-6(-/-) mice with rIL-6 completely reversed the hepatocyte proliferation defect and increased the subsequent level of total apoptotic bodies. The fine control of liver weight recovery during regeneration after PH is a complex process that involves both mitosis and apoptosis. IL-6 affects this process by recruiting, and possibly synchronizing, the entry of hepatocytes into cell cycling, which quickly restores liver mass. However, this robust response generates superfluous hepatocytes, which are eliminated via apoptosis, similar to many other processes involving organ growth.


Assuntos
Apoptose , Hepatectomia , Interleucina-6/deficiência , Fígado/citologia , Mitose , Animais , Ductos Biliares Intra-Hepáticos/citologia , Divisão Celular , DNA/biossíntese , Células Epiteliais/citologia , Feminino , Interleucina-6/sangue , Interleucina-6/farmacologia , Cinética , Regeneração Hepática , Camundongos , Camundongos Mutantes , Tamanho do Órgão , RNA Mensageiro/análise , alfa-Fetoproteínas/genética
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