RESUMEN
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.
Asunto(s)
Apoptosis , Inflamación/patología , Queratinocitos/metabolismo , Queratinocitos/patología , Proteínas del Tejido Nervioso/metabolismo , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Piel/patología , Animales , Apoptosis/efectos de los fármacos , Epidermis/metabolismo , Epidermis/patología , Proteína de Dominio de Muerte Asociada a Fas/metabolismo , Células HEK293 , Humanos , Queratinocitos/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas del Tejido Nervioso/deficiencia , Fenotipo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/deficiencia , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Receptores Tipo I de Factores de Necrosis Tumoral/deficiencia , Transducción de Señal/efectos de los fármacos , Proteína de Dominio de Muerte Asociada a Receptor de TNF/metabolismo , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
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.
Asunto(s)
Envejecimiento/metabolismo , Insuficiencia Cardíaca/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Miocardio/metabolismo , Transducción de Señal , Sirtuina 1/genética , Envejecimiento/genética , Envejecimiento/patología , Animales , Animales Recién Nacidos , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Factor I del Crecimiento Similar a la Insulina/genética , Ratones , Ratones Transgénicos , Proteína Quinasa 8 Activada por Mitógenos/genética , Proteína Quinasa 8 Activada por Mitógenos/metabolismo , Miocardio/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Estrés Oxidativo , Paraquat/farmacología , Cultivo Primario de Células , ARN Interferente Pequeño/genética , Ratas , Sirtuina 1/deficiencia , TransfecciónRESUMEN
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.