Efectos del sistema endocannabinoide en el sistema respiratorio. Papel de los receptores TRPV1 en la fibrogénesis pulmonar / Endocannabinoid system effects on the respiratory system. The role of TRPV1 receptors in pulmonary fibrosis

Objetivos: establecer un modelo murino de fibrosis pulmonar inducida por bleomicina, investigando el posible papel protector del sistema endocannabinoide (SE) frente a la fibrosis. Métodos: se emplearon ratones salvajes (C5BL/6 y Balb/c) así como la cepa TRPV1-/-. Tras una única dosis intratraqueal de bleomicina, se analizó la respuesta fibrótica mediante un análisis histológico, la determinación de la expresión de marcadores del proceso profibrótico, el estudio de la actividad mieloperoxidasa y del contenido en hidroxiprolina del pulmón, así como el análisis de la expresión génica de VIP, PACAP, IL-1β, IL-6, TNF-α e IL-11, y el estado de activación de las rutas MAPKs (fosfo-JNK, fosfo-ERK) de la ruta de NF-κB (p-IκBα), la ruta de β-catenina y del TGFβ (GSK-3B), la activación de SMAD (pSMAD2) y pSTAT3, a nivel proteico. Resultados: la fibrosis pulmonar inducida por bleomicina en los ratones de la cepa TRPV- /- fue más severa que en la cepa salvaje C5BL/6. El contenido en hidroxiprolina y la actividad mieloperoxidasa fue mayor en los ratones TRPV1-/-. Se detectó un incremento significativo en la expresión génica de citoquinas proinflamatorias (TNF-a, IL-1b, IL11 e IL-6), pero no de VIP o PACAP, en la cepa TRPV1-/-. A nivel proteico, la expresión de pIKBα, pSTAT3, pSMAD2 y pJNK, pero no la de pERK, se vio incrementada en los ratones TRPV1-/-. Conclusiones: el modelo murino de fibrosis pulmonar inducida por bleomicina sigue siendo clave para continuar profundizando los conocimientos acerca de la patogénesis de la FPI. La modulación del SE podría tener un papel protector frente a la fibrosis pulmonar

Objectives: to establish a murine model of bleomycin-induced pulmonary fibrosis, analysing the possible protective role of the Endocannabinoid System (ES) against fibrosis. Methods: wild C5BL/6 and Balb/c mice, as well as the genetically modified strain TRPV1- /- were used. After a single dose of intratracheal bleomycin, the fibrotic response was analysed though histologic studies, the assessment of proinflammatory markers, myeloperoxidase activity, hydroxyproline content, genetic expression of VIP, PACAP, IL-1 β, IL-6, TNF-α and IL-11, as well as MAPK route (phospho-JNK, phospho-ERK), NF-κB (p-IκBα), β-cathenin, TGF-β (GSK-3B), SMAD (p-SMAD2) and pSTAT3, at a protein level. Results: pulmonary fibrosis was more severe in TRPV1-/- mice compared to C5BL/6 mice. A significant increase in proinflammatory markers such as TNF-α, IL-1β, IL11 and IL-6, but not VIP or PACAP, was observed. pIKBα, pSTAT3, pSMAD2 and pJNK, but not pERK, were increased at a protein level in TRPV-/- mice. Conclusions: the murine model of bleomycin-induced lung fibrosis remains a keystone to pioneer current investigation in lung fibrosis. Modulation of the ES might have a protective role

Silica induced early fibrogenic reaction in lung of mice ameliorated by Nyctanthes arbortristis extract.

OBJECTIVE: To investigate the pharmacological effect of Nyctanthes arbortristis (NAT) leaf extract in the prevention of lung injury induced by silica particles. METHOD: Lung injury was induced in Swiss mice through inhalation exposure to silica particles (< 5 mu) using a Flow Past Nose Only Inhalation Chamber at the rate of -10 mg/m3 respirable mass for 5 h. Lung bronchoalveolar lavage (BAL) fluid collected between 48 and 72 h was subjected to protein profiling by electrophoresis and cytokine evaluation by solid phase sandwich ELISA. Lung histopathology was performed to evaluate lung injury. RESULTS: Inhalation of silica increased the level of tumor necrosis factor-alpha (TNF-alpha), and of the 66 and 63 kDa peptides in the BAL fluid in comparison to sham-treated control. Pre-treatment of silica exposed mice with NAT leaf extract significantly prevented the accumulation of TNF-alpha in the BAL fluid, but the 66 and 63 kDa peptides remained unchanged. The extract was also effective in the prevention of silica-induced early fibrogenic reactions like congestion, edema and infiltration of nucleated cells in the interstitial alveolar spaces, and thickening of alveolar septa in mouse lung. CONCLUSION: NAT leaf extract helps in bypassing silica induced initial lung injury in mice.