Andrographolide antagonizes cigarette smoke extract-induced inflammatory response and oxidative stress in human alveolar epithelial A549 cells through induction of microRNA-218.

Andrographolide is a major bioactive labdane diterpenoid isolated from Andrographis paniculata and has protective effects against cigarette smoke (CS)-induced lung injury. This study was done to determine whether such protective effects were mediated through modulation of microRNA (miR)-218 expression. Therefore, we exposed human alveolar epithelial A549 cells to cigarette smoke extract (CSE) with or without andrographolide pretreatment and measured the level of glutathione, nuclear factor-kappaB (NF-κB) activation, proinflammatory cytokine production, and miR-218 expression. We found that andrographolide pretreatment significantly restored the glutathione level in CSE-exposed A549 cells, coupled with reduced inhibitor κB (IκB)-α phosphorylation and p65 nuclear translocation and interleukin (IL)-8 and IL-6 secretion. The miR-218 expression was significantly upregulated by andrographolide pretreatment. To determine the biological role of miR-218, we overexpressed and downregulated its expression using miR-218 mimic and anti-miR-218 inhibitor, respectively. We observed that miR-218 overexpression led to a marked reduction in IκB-α phosphorylation, p65 nuclear accumulation, and NF-κB-dependent transcriptional activity in CSE-treated A549 cells. In contrast, miR-218 silencing enhanced IκB-α phosphorylation and p65 nuclear accumulation in cells with andrographolide pretreatment and reversed andrographolide-mediated reduction of IL-6 and IL-8 production. In addition, depletion of miR-218 significantly reversed the upregulation of glutathione levels in A549 cells by andrographolide. Taken together, our results demonstrate that andrographolide mitigates CSE-induced inflammatory response in A549 cells, largely through inhibition of NF-κB activation via upregulation of miR-218, and thus has preventive benefits in CS-induced inflammatory lung diseases.

[A study on the efficacy of glucocorticoid therapy for idiopathic nonspecific interstitial pneumonia].

OBJECTIVE: To investigate the efficacy of glucocorticoid therapy in idiopathic nonspecific interstitial pneumonia (INSIP). METHODS: Twenty-nine cases of INSIP confirmed by clinical- radiological-pathological (CRP) diagnosis were collected and classified into 2 groups according to the degree of fibrosis: INSIP-1 (including 9 cases of cellular type) and INSIP-2 (20 cases of mixed and fibrotic type). Thirty cases of usual interstitial pneumonia (UIP) confirmed by CRP diagnosis served as the control. Clinical and pathological features, therapeutic effects of glucocorticoids and the follow-up results were retrospectively analyzed and the survival curves were evaluated by Kaplan-Meier method. RESULTS: The mean age at onset of INSIP-1 group [(48 ± 5) years] was significantly younger than INSIP-2 group [(52 ± 11) years] and the UIP group [(57 ± 14) years]. The course of disease in INSIP-1 group [(60 ± 28) months] was longer than that in INSIP-2 group [(48 ± 33) months] and that in the UIP group [(44 ± 23) months], but the differences were not statistically significant (F = 1.22, all P > 0.05). The efficacy rate of glucocorticoid treatment in INSIP-1 group (9/9) was higher than that in INSIP-2 group (11/20) and that in the UIP group (2/30), the differences being statistically significant (all P < 0.05). The follow-up period for INSIP-1 group [(56 ± 27) months] was significantly longer than for INSIP-2 group [(23 ± 18) months] and for the UIP group [(25 ± 17) months], and the rate of significant improvement (6/9) was higher than that of the INSIP-2 group (9/20) and the UIP group (0/30), the differences being statistically significant (F = 9.224, all P < 0.05). The mortality of INSIP-1 group (0/9) was lower than that in INSIP-2 group (4/20) and the UIP group (16/30), the difference being statistically significant (exact probability value 0.000 - 0.005, P < 0.05). CONCLUSIONS: The degree of fibrosis of INSIP is closely correlated with the effect of glucocorticoid therapy and prognosis. The cellular type has a favorable reaction to glucocorticoid therapy and a better prognosis as compared to the fibrotic type.