RESUMEN
Released mitochondrial DNA (mtDNA) in cells activates cGAS-STING pathway, which induces expression of interferon-stimulated genes (ISGs) and thereby promotes inflammation, as frequently seen in asthmatic airways. However, whether the genetic determinant, Gasdermin B (GSDMB), the most replicated asthma risk gene, regulates this pathway remains unknown. We set out to determine whether and how GSDMB regulates mtDNA-activated cGAS-STING pathway and subsequent ISGs induction in human airway epithelial cells. Using qPCR, ELISA, native polyacrylamide gel electrophoresis, co-immunoprecipitation and immunofluorescence assays, we evaluated the regulation of GSDMB on cGAS-STING pathway in both BEAS-2B cells and primary normal human bronchial epithelial cells (nHBEs). mtDNA was extracted in plasma samples from human asthmatics and the correlation between mtDNA levels and eosinophil counts was analyzed. GSDMB is significantly associated with RANTES expression in asthmatic nasal epithelial brushing samples from the Genes-environments and Admixture in Latino Americans (GALA) II study. Over-expression of GSDMB promotes DNA-induced IFN and ISGs expression in bronchial epithelial BEAS-2B cells and nHBEs. Conversely, knockout of GSDMB led to weakened induction of interferon (IFNs) and ISGs in BEAS-2B cells. Mechanistically, GSDMB interacts with the C-terminus of STING, promoting the translocation of STING to Golgi, leading to the phosphorylation of IRF3 and induction of IFNs and ISGs. mtDNA copy number in serum from asthmatics was significantly correlated with blood eosinophil counts especially in male subjects. GSDMB promotes the activation of mtDNA and poly (dA:dT)-induced activation of cGAS-STING pathway in airway epithelial cells, leading to enhanced induction of ISGs.
RESUMEN
RESUMEN Los bifosfonatos se utilizan para el manejo de enfermedades con incremento de la resorción ósea como la osteoporosis, la enfermedad metastásica ósea y la hipercalcemia maligna, entre otras patologías. En los últimos años se ha reportado que el uso de bifosfonatos intravenosos como el zoledronato y el pamidronato pueden generar efectos adversos oculares, ocasionados por una reacción de fase aguda mediada por la interleucina-6 (IL-6) y factor de necrosis tumoral alfa (TNF-a). Se reportan 2 casos (una mujer de 71 años y un hombre de 67 años) que entre las 24 a 72 h después de recibir terapia con zoledronato presentaron una uveítis anterior.
ABSTRACT Bisphosphonates are used in the management of diseases characterized by an increase in bone resorption such as osteoporosis, metatasic bone disease, malignant hypercalcemia among others. It has been reported that the use of IV bisphosphonates as zoledronate and pamidronate generate ocular adverse effects by an acute phase reaction mediated by an increase of interleukin 6 (IL-6) and tumoral necrosis factor (TNF-a). We present 2 cases, a woman 71 years old and a 67 years old man that received therapy with bisphosphonates and 24 to 72hours later they presented an anterior uveitis.
