RESUMO
This study assessed the influence of Christian beliefs on attitudes toward people with mental illness. Participants (N=204) provided demographic information and completed the Christian Orthodoxy Scale, the Religious Fundamentalism Scale, and the Attitudes to Mental Illness Questionnaire. Participants read vignettes of a person with a mental illness (schizophrenia), a general medical illness (diabetes), and a control condition (practicing Christian) and rated them on five criteria representing stigmatizing attitudes. The data were analyzed by sequential multiple regression. Religious fundamentalism, but not Christian orthodoxy, was a significant predictor of stigmatizing attitudes toward a person with mental illness. Consistent with past research, neither religious fundamentalism nor Christian orthodoxy were significant predictors of stigmatizing attitudes toward a general medical illness. As predicted, both religious fundamentalism and Christian orthodoxy were significant predictors of positive attitudes toward a practicing Christian. Sensitivity and discourse regarding stigmatization and deeply held fundamental religious beliefs are needed among mental health professionals, religious leaders, and laypersons.
Assuntos
Atitude , Cristianismo/psicologia , Pessoas Mentalmente Doentes , Estereotipagem , Inquéritos e Questionários , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estigma Social , Adulto JovemRESUMO
Obtustatin and viperistatin represent the shortest known snake venom monomeric disintegrins. In the present study, we have produced recombinant full-length wild-type and site-directed mutants of obtustatin to assess the role of the K(21)TS(23) tripeptide and C-terminal residues for specific inhibition of the alpha(1)beta(1) integrin. Thr(22) appeared to be the most critical residue for disintegrin activity, whereas substitution of the flanking lysine or serine residues for alanine resulted in a less pronounced decrease in the anti-alpha(1)beta(1) integrin activity of the disintegrin. The triple mutant A(21)AA(23) was devoid of blocking activity towards alpha(1)beta(1) integrin-mediated cell adhesion. The potency of recombinant KTS-disintegrins also depended on the residue C-terminally adjacent to the active motif. Substitution of Leu(24) of wild-type obtustatin for an alanine residue slightly decreased the inhibitory activity of the mutant, whereas an arginine residue in this position enhanced the potency of the mutant over wild-type obtustatin by 6-fold. In addition, the replacements L38V and P40Q may account for a further 25-fold increase in alpha(1)beta(1) inhibitory potency of viperistatin over KTSR-obtustatin.
Assuntos
Motivos de Aminoácidos , Desintegrinas/farmacologia , Integrina alfa1beta1/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Colágeno Tipo IV/metabolismo , Simulação por Computador , Desintegrinas/química , Desintegrinas/genética , Ensaio de Imunoadsorção Enzimática , Humanos , Integrina alfa1beta1/metabolismo , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Ligação Proteica/efeitos dos fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Homologia de Sequência de Aminoácidos , Venenos de Serpentes/química , Venenos de Serpentes/metabolismo , Venenos de Serpentes/farmacologia , Relação Estrutura-Atividade , Venenos de Víboras/química , Venenos de Víboras/genética , Venenos de Víboras/farmacologiaRESUMO
The presented results show the effect of targeting of collagen receptor, alpha1beta1 integrin expressed on the endothelial cells on the development of experimental melanoma and pathological angiogenesis. Obtustatin, a snake venom KTS-disintegrin, was applied as a specific inhibitor of this integrin. This low molecular weight peptide revealed a potent therapeutic effect on melanoma progression in 2 animal systems, mouse and quail. Its oncostatic effect was related to the inhibition of angiogenesis. Obtustatin inhibited the neovascularization ratio on the CAM embryo of quail, which was pathologically induced by the developing tumor. The i.v. administration of obtustatin completely blocked cancer growth of MV3 human melanoma in nude mice. In B16F10 syngeneic mouse model treatment with the disintegrin revealed a lower effect, although the development of the tumor was significantly reduced for both dosages. The mechanism of obtustatin action is related to the blocking of microvascular endothelial cell proliferation, which undergoes apoptosis in caspase-dependent manner. Summarizing, we present studies of low molecular weight disintegrin, obtustatin as a potential therapeutic compound for treatment of melanoma that contain a high level of vascularization.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Integrina alfa1beta1/antagonistas & inibidores , Melanoma Experimental/tratamento farmacológico , Venenos de Víboras/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Membrana Corioalantoide/efeitos dos fármacos , Coturnix , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Humanos , Melanoma Experimental/irrigação sanguínea , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Venenos de Víboras/farmacologiaRESUMO
In the present study we described the role of alpha9beta1 integrin in glioblastoma progression following its interaction with nerve growth factor (NGF). The level of expression of alpha9beta1 on astrocytomas is correlated with increased grade of this brain tumor and is highest on glioblastoma, whereas normal astrocytes do not express this integrin. Two glioblastoma cell lines, LN229 and LN18, that are alpha9beta1 integrin positive and negative, respectively, were used for alpha9beta1 integrin-dependent NGF-induced tumor progression. NGF was a significant promoter of promigratory and pro-proliferative activities of glioblastoma cells through direct interaction with alpha9beta1 integrin and activation of MAPK Erk1/2 pathway. The level of NGF increases approximately threefold in the most malignant glioma tissue when compared with normal brain. This increase is related to secretion of NGF by tumor cells. Specific inhibitors of alpha9beta1 integrin or gene silencing inhibited NGF-induced proliferation of LN229 cell line to the level shown by LN18 cells. VLO5 promoted alpha9beta1-dependent programmed cell death by induction of intrinsic apoptosis pathway in cancer cells. LN229 cells were rescued from proapoptotic effect of VLO5 by the presence of NGF. This disintegrin significantly inhibited tumor growth induced by implantation of LN229 cells to the chorioallantoic membrane (CAM) of quail embryonic model, and this inhibitory effect was significantly abolished by the presence of NGF. alpha9beta1 integrin appears to be an interesting target for blocking the progression of malignant gliomas, especially in light of the stimulatory effect of NGF on the development of these tumors and its ability to transfer proapoptotic signals in cancer cells.
Assuntos
Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Integrinas/metabolismo , Fator de Crescimento Neural/metabolismo , Animais , Apoptose , Western Blotting , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Glioblastoma/patologia , Humanos , Imuno-Histoquímica , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The integrin alpha9beta1 is a multifunctional receptor that interacts with a variety of ligands including vascular cell adhesion molecule 1, tenascin C and osteopontin. We found that this integrin is a receptor for nerve growth factor (NGF) and two other neurotrophins, brain-derived neurotrophic factor and NT3, using a cell adhesion assay with the alpha9SW480 cell line. Interaction of alpha9beta1 with NGF was confirmed in an ELISA assay by direct binding to purified integrin. alpha9beta1 integrin binds to neurotrophins in a manner similar to another common neurotrophin receptor, p75(NTR) (NGFR), although alpha9beta1 activity is correlated with induction of pro-survival and pro-proliferative signaling cascades. This property of alpha9beta1 resembles the interaction of NGF with a high affinity receptor, TrkA, however, this integrin shows a low affinity for NGF. NGF induces chemotaxis of cells expressing alpha9beta1 and their proliferation. Moreover, alpha9beta1 integrin is a signaling receptor for NGF, which activates the MAPK (Erk1/2) pathway. The alpha9beta1-dependent chemotactic ability of NGF appears to result from the activation of paxillin.
Assuntos
Integrinas/metabolismo , Fator de Crescimento Neural/farmacologia , Fatores de Crescimento Neural/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Humanos , Ligação Proteica , Ratos , Receptor de Fator de Crescimento Neural/genética , Receptor de Fator de Crescimento Neural/metabolismo , Receptor trkA/genética , Receptor trkA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Therapeutic angiogenesis is one of the major approaches in designing new therapies for cardiovascular diseases. vpVEGF was purified from Vipera palestinae venom using two steps of reverse-phase HPLC. Structurally, vpVEGF belongs to the VEGF-F1 family of snake venom proteins, and potently stimulated dHMVEC proliferation in a VEGFR-2 dependent manner. This growth factor appeared to be a chemoattractant for migration of these cells and stimulated their radial migration in a collagen gel. The stimulatory effect on dHMVEC was correlated with activation of the MAPK Erk1/2 signaling pathway. In vivo vpVEGF induced angiogenesis in a Japanese quail assay and in a Matrigel plug assay in mice. Although in the quail assay vpVEGF showed lower activity than hrVEGF-A165 in mammalian-related systems there were no significant differences. The experiments with dHMVEC, as well as angiogenesis in vivo suggest that the pro-angiogenic effect of vpVEGF is related to its interaction with VEGFR-2 (flk-1).