RESUMO
Transcription factor NF-κB is persistently activated in many chronic inflammatory diseases and cancers. The short term regulation of NF-κB is well understood, but little is known about the mechanisms of its long term activation. We studied the effect of a single application of TNF-α on NF-κB activity for up to 48 h in intestinal epithelial cells. Results show that NF-κB remained persistently activated up to 48 h after TNF-α and that the long term activation of NF-κB was accompanied by a biphasic degradation of IκBα. The first phase of IκBα degradation was proteasome-dependent, but the second was not. Further investigation showed that TNF-α stimulated formation of autophagosomes in intestinal epithelial cells and that IκBα co-localized with autophagosomal vesicles. Pharmacological or genetic blockade of autophagosome formation or the inhibition of lysosomal proteases decreased TNF-α-induced degradation of IκBα and lowered NF-κB target gene expression. Together, these findings indicate a role of autophagy in the control of long term NF-κB activity. Because abnormalities in autophagy have been linked to ineffective innate immunity, we propose that alterations in NF-κB may mediate this effect.
Assuntos
Autofagia/fisiologia , Proteínas I-kappa B/metabolismo , NF-kappa B/metabolismo , Fagossomos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Humanos , Proteínas I-kappa B/genética , Proteínas I-kappa B/imunologia , Imunidade Inata/fisiologia , Camundongos , Camundongos Knockout , Inibidor de NF-kappaB alfa , NF-kappa B/genética , NF-kappa B/imunologia , Células NIH 3T3 , Fagossomos/genética , Fagossomos/imunologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Background: It is estimated that 225 million women worldwide have an unmet need for family planning, and more than half live in low- and middle-income countries. Increasing the choice of contraceptive methods available can reduce this unmet need. Microneedle drug delivery systems represent a new technology for minimally invasive self-administration of contraceptives. We explored stakeholders' views on different aspects of a proposed microneedle-based hormonal contraceptive delivery system. The feedback was used to iteratively develop this delivery system. Methods: Focus group discussions and semi-structured interviews were conducted with potential stakeholders (women and trans males of childbearing age, their partners, and health professionals and organisations that provide family planning advice and contraception services) in Uganda, The Gambia, Malawi, and the UK, exploring concept acceptability and gathering feedback on different aspects of design and usability of the proposed delivery system. Results: Participants viewed the concept of a new, microneedle-based contraceptive favourably. In Uganda, participants were presented with 7 different prototype applicators and identified desirable features of a preferred delivery device; their input reducing the number of prototypes that were subsequently evaluated by stakeholders in The Gambia and the UK. Participants in these countries helped to identify and/or confirm the most desirable characteristics of the applicator, resulting in design consolidation into a refined concept applicator. The final, optimised applicator prototype was validated during user research in Malawi. This human-centred design approach was also used to iteratively develop an information leaflet for the device. During these user studies, other preferred aspects of a contraceptive delivery system were also evaluated, such as anatomical site of application, duration of action, and return to fertility. Conclusions: A new microneedle-based contraceptive delivery system was iteratively developed using a human-centred design approach and was favourably received by potential stakeholders. The product is now being refined for testing in pre-clinical studies.
RESUMO
Intestinal epithelial cells play critical roles in regulating mucosal immunity. Since epigenetic factors such as DNA methylation and histone modifications are implicated in aging, carcinogenesis, and immunity, we set out to assess any role for epigenetic factors in the regulation of intestinal epithelial cell immune responses. Experiments were conducted using the HCT116 cell line, and a subclone was genetically engineered to lack DNA methyltransferases (DNMT). The induction of the chemokine interleukin-8 and the antiapoptotic protein cFLIP by tumor necrosis factor-alpha were markedly less in HCT116 cells lacking DNMT than in parental cells. These effects were accompanied by lower monocyte chemotaxis and higher caspase signaling in HCT116 cells lacking DNMT than parental cells. Tumor necrosis factor-alpha-induced NF-kappaB activation was blocked and IkappaBalpha expression was higher in HCT116 cells lacking DNMT than in parental cells. A CpG island in the IkappaBalpha gene promoter region was found to contain variable levels of methylation in parental HCT116 cells. Chromatin immunoprecipitation analysis of histone proteins bound to the IkappaBalpha gene promoter revealed that higher levels of IkappaBalpha expression in HCT116 cells lacking DNMT compared with parental cells were accompanied by more chromatin marks permissive to gene transcription. These findings show that epigenetic factors influence the NF-kappaB system in intestinal epithelial cells, resulting in a previously unrecognized mechanism of innate immune regulation.
Assuntos
Metilação de DNA , Epigênese Genética , Células Epiteliais/imunologia , Quinase I-kappa B/metabolismo , Imunidade nas Mucosas/genética , Mucosa Intestinal/imunologia , NF-kappa B/metabolismo , Sítios de Ligação , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Caspase 3/metabolismo , Quimiotaxia de Leucócito , Montagem e Desmontagem da Cromatina , Ilhas de CpG , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Células HCT116 , Histonas/metabolismo , Humanos , Quinase I-kappa B/genética , Interleucina-8/metabolismo , Monócitos/imunologia , Regiões Promotoras Genéticas , Fatores de Tempo , Ativação Transcricional , Fator de Necrose Tumoral alfa/metabolismoAssuntos
Acessibilidade aos Serviços de Saúde/organização & administração , Serviços de Saúde Materna/organização & administração , Mortalidade Materna , Bem-Estar Materno/estatística & dados numéricos , Complicações na Gravidez/prevenção & controle , Prevenção Primária/organização & administração , Chade , Feminino , Humanos , Recém-Nascido , Centros de Saúde Materno-Infantil/organização & administração , Cuidado Pós-Natal/organização & administração , Gravidez , Complicações na Gravidez/epidemiologia , Saúde da MulherRESUMO
Empirically supported treatments (EST) hold much promise in relieving psychological distress and dysfunction. However, various obstacles to effective training and clinical practice have truncated dissemination efforts. One such obstacle is the perceived applicability of EST procedures to raw world clinical practice. This article proposes a rubric for supervision that emphasizes case conceptualization, the use of immediacy in session, tolerating negative affect, harvesting open attitudes, cultural responsiveness, and technical proficiency. Several specific training strategies and supervisory processes are recommended.