RESUMO
Activation of fibroblasts is essential for physiological tissue repair. Uncontrolled activation of fibroblasts, however, may lead to tissue fibrosis with organ dysfunction. Although several pathways capable of promoting fibroblast activation and tissue repair have been identified, their interplay in the context of chronic fibrotic diseases remains incompletely understood. Here, we provide evidence that transforming growth factor-ß (TGFß) activates autophagy by an epigenetic mechanism to amplify its profibrotic effects. TGFß induces autophagy in fibrotic diseases by SMAD3-dependent downregulation of the H4K16 histone acetyltransferase MYST1, which regulates the expression of core components of the autophagy machinery such as ATG7 and BECLIN1. Activation of autophagy in fibroblasts promotes collagen release and is both, sufficient and required, to induce tissue fibrosis. Forced expression of MYST1 abrogates the stimulatory effects of TGFß on autophagy and re-establishes the epigenetic control of autophagy in fibrotic conditions. Interference with the aberrant activation of autophagy inhibits TGFß-induced fibroblast activation and ameliorates experimental dermal and pulmonary fibrosis. These findings link uncontrolled TGFß signaling to aberrant autophagy and deregulated epigenetics in fibrotic diseases and may contribute to the development of therapeutic interventions in fibrotic diseases.
Assuntos
Autofagia/genética , Epigênese Genética , Histona Acetiltransferases/metabolismo , Escleroderma Sistêmico/patologia , Fator de Crescimento Transformador beta/metabolismo , Adulto , Idoso , Animais , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Biópsia , Estudos de Casos e Controles , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Fibroblastos , Fibrose , Técnicas de Inativação de Genes , Voluntários Saudáveis , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Células NIH 3T3 , Cultura Primária de Células , Receptores de Fatores de Crescimento Transformadores beta , Transdução de Sinais/genética , Pele/citologia , Pele/patologia , Proteína Smad3/metabolismo , Adulto JovemRESUMO
Cordyceps militaris (C. militaris) is a fungus with a long history of widespread use in folk medicine, and its biological and medicinal functions are well studied. A crucial pharmacological effect of C. militaris is immunomodulation. In this review, we catalog the immunomodulatory effects of different extracts of C. militaris, namely total extracts, polysaccharides and cordycepin. Total extracts obtained using water or 50% ethyl alcohol and polysaccharides from C. militaris were discovered to tend to promote type 1 immunity, whereas total extracts obtained using 70-80% ethyl alcohol and cordycepin from C. militaris were more likely to promote type 2 immunity. This article is the first to classify the immunomodulatory effects of different extracts of C. militaris. In addition, we discovered a relationship between different segments or extracts and differing types of immunity. This review can provide the readers a comprehensive understanding on the immunomodulatory effects of the precious folk medicine and guidance on its use for both health people and those with an immunodeficiency.
RESUMO
Human haptoglobin (Hp) is classified as three phenotypes: Hp 1-1, 2-1, and 2-2. Previously, we had isolated this protein by affinity columns using either hemoglobin or monoclonal antibody (mAb) prepared against Hp beta-chain (clone 8B1-3A). The isolated Hp from both methods, however, contaminates plasma apolipoprotein A-I (apoA-I). In the present report, we have developed a novel affinity column procedure using an mAb prepared against alpha-chain of Hp (clone 3H8) for Hp purification. Plasma was first chromatographed onto the column followed by a normal wash with a buffer containing 0.12 M NaCl and 0.02 M phosphate, pH 7.4 (PBS). The bound proteins were then prewashed with a 0.04% sodium dodecyl sulfate (SDS)-PBS, pH 7.4, to remove the low-affinity bound apoA-I from Hp. Finally, the bound Hp was eluted with a 0.1% SDS-PBS, pH 11, and collected in tubes containing 1 M Tris-HCl, pH 6.8. As a result, the isolated Hp was devoid of apoA-I and was able to retain the biological function by forming an Hp-hemoglobin complex. The homogeneity of each isolated Hp 1-1, 2-1, or 2-2 was greater than 95% with an yield greater than 50%. The procedure described here is significantly improved in time consumption, recovery, and purity. The rationale, design, and optimization for each step are described in detail.