RESUMO
Linear Ubiquitin chain Assembly Complex (LUBAC) is an E3 ligase complex that generates linear ubiquitin chains and is important for tumour necrosis factor (TNF) signaling activation. Mice lacking Sharpin, a critical subunit of LUBAC, spontaneously develop inflammatory lesions in the skin and other organs. Here we show that TNF receptor 1 (TNFR1)-associated death domain (TRADD)-dependent TNFR1 signaling in epidermal keratinocytes drives skin inflammation in Sharpin-deficient mice. Epidermis-restricted ablation of Fas-associated protein with death domain (FADD) combined with receptor-interacting protein kinase 3 (RIPK3) deficiency fully prevented skin inflammation, while single RIPK3 deficiency only delayed and partly ameliorated lesion development in Sharpin-deficient mice, showing that inflammation is primarily driven by TRADD- and FADD-dependent keratinocyte apoptosis while necroptosis plays a minor role. At the cellular level, Sharpin deficiency sensitized primary murine keratinocytes, human keratinocytes, and mouse embryonic fibroblasts to TNF-induced apoptosis. Depletion of FADD or TRADD in Sharpin-deficient HaCaT cells suppressed TNF-induced apoptosis, indicating the importance of FADD and TRADD in Sharpin-dependent anti-apoptosis signaling in keratinocytes.
Assuntos
Apoptose , Inflamação/patologia , Queratinócitos/metabolismo , Queratinócitos/patologia , Proteínas do Tecido Nervoso/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Pele/patologia , Animais , Apoptose/efeitos dos fármacos , Epiderme/metabolismo , Epiderme/patologia , Proteína de Domínio de Morte Associada a Fas/metabolismo , Células HEK293 , Humanos , Queratinócitos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/deficiência , Fenótipo , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Transdução de Sinais/efeitos dos fármacos , Proteína de Domínio de Morte Associada a Receptor de TNF/metabolismo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Oxidative stress contributes to the pathogenesis of aging-associated heart failure. Among various signaling pathways mediating oxidative stress, the NAD(+) -dependent protein deacetylase SirT1 has been implicated in the protection of heart muscle. Expression of a locally acting insulin-like growth factor-1 (IGF-1) propeptide (mIGF-1) helps the heart to recover from infarct and enhances SirT1 expression in cardiomyocytes (CM) in vitro, exerting protection from hypertrophic and oxidative stresses. To study the role of mIGF-1/SirT1 signaling in vivo, we generated cardiac-specific mIGF-1 transgenic mice in which SirT1 was depleted from adult CM in a tamoxifen-inducible and conditional fashion. Analysis of these mice confirmed that mIGF-1-induced SirT1 activity is necessary to protect the heart from paraquat (PQ)-induced oxidative stress and lethality. In cultured CM, mIGF-1 increases SirT1 expression through a c-Jun NH(2)-terminal protein kinase 1 (JNK1)-dependent signaling mechanism. Thus, mIGF-1 protects the heart from oxidative stress via SirT1/JNK1 activity, suggesting new avenues for cardiac therapy during aging and heart failure.
Assuntos
Envelhecimento/metabolismo , Insuficiência Cardíaca/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Miocárdio/metabolismo , Transdução de Sinais , Sirtuína 1/genética , Envelhecimento/genética , Envelhecimento/patologia , Animais , Animais Recém-Nascidos , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Fator de Crescimento Insulin-Like I/genética , Camundongos , Camundongos Transgênicos , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Estresse Oxidativo , Paraquat/farmacologia , Cultura Primária de Células , RNA Interferente Pequeno/genética , Ratos , Sirtuína 1/deficiência , TransfecçãoRESUMO
Progress in the somatosensory field has been restricted by the limited number of genetic tools available to study gene function in peripheral sensory neurons. Here we generated a Cre-driver mouse line that expresses Cre-recombinase from the locus of the sensory neuron specific gene Advillin. These mice displayed almost exclusive Cre-mediated recombination in all peripheral sensory neurons. As such, the Advillin-Cre-driver line will be a powerful tool for targeting peripheral neurons in future investigations.