Prostaglandin E(2) (PGE(2)) inhibits fibroblast proliferation and collagen production. Its synthesis by fibroblasts is induced by profibrotic mediators including transforming growth factor (TGF)-beta(1). However, in patients with pulmonary fibrosis, PGE(2) levels are decreased. In this study we examined the effect of TGF-beta(1) on PGE(2) synthesis, proliferation, collagen production, and cyclooxygenase (COX) mRNA levels in fibroblasts derived from fibrotic and nonfibrotic human lung. In addition, we examined the effect of bleomycin-induced pulmonary fibrosis in COX-2-deficient mice. We demonstrate that basal and TGF-beta(1)-induced PGE(2) synthesis is limited in fibroblasts from fibrotic lung. Functionally, this correlates with a loss of the anti-proliferative response to TGF-beta(1). This failure to induce PGE(2) synthesis is because of an inability to up-regulate COX-2 mRNA levels in these fibroblasts. Furthermore, mice deficient in COX-2 exhibit an enhanced response to bleomycin. We conclude that a decreased capacity to up-regulate COX-2 expression and COX-2-derived PGE(2) synthesis in the presence of increasing levels of profibrotic mediators such as TGF-beta(1) may lead to unopposed fibroblast proliferation and collagen synthesis and contribute to the pathogenesis of pulmonary fibrosis.

Mahjong is a novel Lethal giant larvae-binding protein that plays a vital role in cell competition in both flies and mammals.

Little is known about the pathogenesis of cough in idiopathic pulmonary fibrosis (IPF). We hypothesized that abnormalities of respiratory tract tachykinin-containing sensory nerves may be implicated. We studied cough response to capsaicin, substance P (SP), and bradykinin in 10 healthy control subjects and 10 patients with IPF. Six patients were tested before and after steroid therapy. Induced sputum cell counts and neurotrophic factor levels were also measured in 13 patients and 13 control subjects. The results show that cough sensitivity to capsaicin was greater in patients (p < 0.01). Neither SP nor bradykinin induced cough in normal subjects. SP and bradykinin induced cough in 7/10 patients (p < 0.002) and 2/10 patients (not significant) with IPF, respectively. Prednisolone caused a reduction in cough sensitivity to capsaicin (p < 0.05) and SP (p < 0.05) in all six patients treated. There were significantly more neutrophils (p = 0.001) and higher levels of nerve growth factor (p < 0.01) and brain-derived neurotrophic factor (p < 0.01) in patient's sputa. These findings suggest functional upregulation of lung sensory neurones in IPF. The cough response to inhaled SP in most patients may reflect disrupted respiratory epithelium. The response to corticosteroids demonstrates that the cough is amenable to therapy.

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic, fibrotic interstitial lung disease of unknown origin. It has a median survival of three years but a wide range in survival rate which is difficult to predict at the time of diagnosis. Specialist guidance promotes a patient centred approach emphasising regular assessment, information giving and supportive care coordinated by a multidisciplinary team (MDT). However understanding of patient and carer experience across the disease trajectory is limited and detailed guidance for MDTs on communication, assessment, and triggers for supportive and palliative interventions is lacking. This study addresses uncertainties relating to care needs of patients and carers at different stages of the IPF disease trajectory.MethodsFollowing ethical approval a multi-centre mixed-methods study recruited participants with IPF at four stages of the disease trajectory. Qualitative analysis was used to analyse 48 semi-structured interviews with patients (27) and paired carers (21).ResultsPatients and carers outlined key elements of MDT activity capable of having significant impact on the care experience. These were structured around:Focus of clinical encountersTimely identification of changes in health status and functional activityUnderstanding of symptoms and medical interventionsCoping strategies and carer roles.ConclusionsPatients diagnosed with IPF have a clear understanding of their prognosis but little understanding of how their disease will progress and how it will be managed. In depth analysis of the experiences of patients and carers offers guidance for refining IPF clinical pathways. This will support patients and carers at key transition points in line with National Institute for Health and Care Excellence (NICE) guidance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-015-0145-5) contains supplementary material, which is available to authorized users.