RESUMO
Mutations in CFTR lead to dysfunction of tubular organs, which is currently attributed to impairment of its conductive properties. We now show that CFTR regulates tight junction assembly and epithelial cell differentiation through modulation of the ZO-1-ZONAB pathway. CFTR colocalizes with ZO-1 at the tight junctions of trachea and epididymis, and is expressed before ZO-1 in Wolffian ducts. CFTR interacts with ZO-1 through the CTFR PDZ-binding domain. In a three-dimensional (3D) epithelial cell culture model, CFTR regulates tight junction assembly and is required for tubulogenesis. CFTR inhibition or knockdown reduces ZO-1 expression and induces the translocation of the transcription factor ZONAB (also known as YBX3) from tight junctions to the nucleus, followed by upregulation of the transcription of CCND1 and downregulation of ErbB2 transcription. The epididymal tubules of cftr(-/-) and cftr(ΔF508) mice have reduced ZO-1 levels, increased ZONAB nuclear expression, and decreased epithelial cell differentiation, illustrated by the reduced expression of apical AQP9 and V-ATPase. This study provides a new paradigm for the etiology of diseases associated with CFTR mutations, including cystic fibrosis.
Assuntos
Núcleo Celular/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Fibrose Cística/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/fisiologia , Junções Íntimas/fisiologia , Fatores de Transcrição/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo , Animais , Diferenciação Celular/genética , Células Cultivadas , Ciclina D1/genética , Ciclina D1/metabolismo , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Organogênese/genética , Ligação Proteica , Transporte Proteico/genética , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genética , Proteína da Zônula de Oclusão-1/genéticaRESUMO
Cystic fibrosis (CF) is the most common life-limiting recessive genetic disease among Caucasians caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) with over 95% male patients infertile. However, whether CFTR mutations could affect spermatogenesis and result in azoospermia remains an open question. Here we report compromised spermatogenesis, with significantly reduced testicular weight and sperm count, and decreased cAMP-responsive element binding protein (CREB) expression in the testes of CFTR knockout mice. The involvement of CFTR in HCO(3) (-) transport and the expression of the HCO(3) (-) sensor, soluble adenylyl cyclase (sAC), are demonstrated for the first time in the primary culture of rat Sertoli cells. Inhibition of CFTR or depletion of HCO(3) (-) could reduce FSH-stimulated, sAC-dependent cAMP production and phosphorylation of CREB, the key transcription factor in spermatogenesis. Decreased CFTR and CREB expression are also observed in human testes with azoospermia. The present study reveals a previously undefined role of CFTR and sAC in regulating the cAMP-CREB signaling pathway in Sertoli cells, defect of which may result in impaired spermatogenesis and azoospermia. Altered CFTR-sAC-cAMP-CREB functional loop may also underline the pathogenesis of various CF-related diseases.
Assuntos
Azoospermia/etiologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/fisiologia , Fibrose Cística/patologia , Espermatogênese/fisiologia , Adenilil Ciclases/metabolismo , Adulto , Animais , Azoospermia/metabolismo , Azoospermia/patologia , Bicarbonatos/metabolismo , Western Blotting , AMP Cíclico/metabolismo , Fibrose Cística/metabolismo , Modelos Animais de Doenças , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Fosforilação , Ratos , Ratos Sprague-Dawley , Células de Sertoli/metabolismo , Células de Sertoli/patologia , Adulto JovemRESUMO
AIM: To explore the biological effect of (60)Cogamma ray on alveolar type II cells and interstitial cells of alveoliar septum. METHODS: Alveolar type II cells(AT-II) and interstitial cells including interstitial macrophages and fibroblasts were irradiated by 0, 3, 5, 7 Gy of gamma ray respectively. The effect of irradiation on AT-II proliferation was observed by argentation against nucleus. The activity of MMP-2, -9 in supernatants from AT-II and interstitial cells after irradiation was determined by zymography. The levels of TGF-beta1 and collagen type IV in supernatant from interstitial cells after irradiation were measured by ELISA. RESULTS: The nucleolus number of AT-II was increased with the increase of irradiation dose and group 7 Gy reached the highest level. The activity of MMP-2, -9 in supernatant from AT-II after irradiation increased at first and then decreased gradually. The activity of MMP-2, -9 and the content of TGF-beta1 in interstitial cells increased step by step, but collagen type IV decreased at first and then increased. CONCLUSION: AT-II, macrophages and fibroblasts are all involved in pulmonary invalid remodeling course in early radiation pulmonary injury, which is related to the initiation of pulmonary fibrosis in late period.
