Serum extracellular vesicular miR-21-5p is a predictor of the prognosis in idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis. Although the median survival is 3 years, the clinical course varies to a large extent among IPF patients. To date, there has been no definitive prognostic marker. Extracellular vesicles (EVs) are known to hold nucleic acid, including microRNAs, and to regulate gene expression in the recipient cells. Moreover, EVs have been shown to express distinct surface proteins or enveloped microRNAs depending on the parent cell or pathological condition. We aimed to identify serum EV microRNAs that would be prognostic for IPF. METHODS: To determine target microRNAs in IPF, we measured serum EV microRNA expression profiles using microRNA PCR arrays in a bleomycin mouse model and validated the microRNAs in additional mice using RT-PCR. Secondly, we enrolled 41 IPF patients and conducted a 30-month prospective cohort study. Expression of serum EV miR-21-5p was normalized by dividing by the EV amount. The relative amount of EVs was measured using the ExoScreen method. We calculated the correlations between baseline serum EV miR-21-5p expression and other clinical variables. Furthermore, we determined if serum EV miR-21-5p can predict mortality during 30 months using the Cox hazard model. According to the median level, we divided the IPF patients into two groups. Then we compared the survival rate during 30 months between the two groups using the Kaplan-Meier method. RESULTS: Serum EV miR-21-5p was elevated in both the acute inflammatory phase (day 7) and the chronic fibrotic phase (day 28) in the mouse model. In the clinical setting, serum EV miR-21-5p was significantly higher in IPF patients than in healthy control subjects. The baseline serum EV miR-21-5p was correlated with the rate of decline in vital capacity over 6 months. Furthermore, serum EV miR-21-5p was independently associated with mortality during the following 30 months, even after adjustment for other variables. In the survival analysis, IPF patients whose baseline serum EV miR-21-5p was high had a significantly poorer prognosis over 30 months. CONCLUSIONS: Our results suggest that serum EV miR-21-5p has potential as a prognostic biomarker for IPF.

Long-term use of corticosteroid eye drops delays the spontaneous remission of pulmonary sarcoidosis.

Topical corticosteroid eye drops are commonly used for ocular sarcoidosis. That systemic absorption of corticosteroids by eye drops may influence the clinical course of sarcoidosis may be speculated because it has been reported that the serum concentration of corticosteroids after drop administration was dose-related. To evaluate the effects of corticosteroid eye drops on the clinical course of patients with stage I pulmonary sarcoidosis, we compared the serum levels of angiotensin converting enzyme (ACE) and bilateral hilar lymphadenopathy (BHL) on chest radiographs of group CS, which is consisted of patients who received topical therapy of betamethasone in the form of eye drops for anterior uveitis, and group CN, which is consisted of patients who did not receive any medications throughout the entire course of the disease. Although the serum ACE level was not significantly different between groups CS and CN at the time of the diagnosis of pulmonary sarcoidosis, the level of serum ACE in group CS was significantly higher than that in group CN 20 months after the topical corticosteroid treatment (24 IU/ml and 16 IU/ml, respectively). Further, the size of BHL on chest radiography in group CS was significantly larger than that in group CN 20 months after the topical treatment (82% and 37% of before control, respectively). These findings suggest the possibility that the topical corticosteroid therapy influenced the clinical course of pulmonary sarcoidosis, inducing some delay in the spontaneous remission in the longterm course.

Cyclic ADP-ribose, a putative Ca2+-mobilizing second messenger, operates in submucosal gland acinar cells.

Cyclic ADP-ribose (cADPR), a putative Ca(2+)-mobilizing second messenger, has been reported to operate in several mammalian cells. To investigate whether cADPR is involved in electrolyte secretion from airway glands, we used a patch-clamp technique, the measurement of microsomal Ca(2+) release, quantification of cellular cADPR, and RT-PCR for CD38 mRNA in human and feline tracheal glands. cADPR (>6 microM), infused into the cell via the patch pipette, caused ionic currents dependent on cellular Ca(2+). Infusions of lower concentrations (2-4 microM) of cADPR or inositol 1,4,5-trisphosphate (IP(3)) alone were without effect on the baseline current, but a combined application of cADPR and IP(3) mimicked the cellular response to low concentrations of acetylcholine (ACh). Microsomes derived from the isolated glands released Ca(2+) in response to both IP(3) and cADPR. cADPR released Ca(2+) from microsomes desensitized to IP(3) or those treated with heparin. The mRNA for CD38, an enzyme protein involved in cADPR metabolism, was detected in human tissues, including tracheal glands, and the cellular content of cADPR was increased with physiologically relevant concentrations of ACh. We conclude that cADPR, in concert with IP(3), operates in airway gland acinar cells to mobilize Ca(2+), resulting in Cl(-) secretion.

Effect of antisense oligonucleotides to nuclear factor-kappaB on the survival of LPS-induced ARDS in mouse.

Because nuclear factor (NF)-kappaB-regulated cytokines, including tumor necrosis factor-alpha (TNF-alpha), from monocytes and macrophages have been implicated in the pathogenesis and development of septic shock and acute respiratory distress syndrome (ARDS), the effect of the antisense oligonucleotide to the p65 subunit of NF-kappaB on the survival of lipopolysaccharide (LPS)-induced ARDS in BALB/c mice was examined. None and 70% of the animals died of diffuse hemorrhagic lung edema 1 to 2.5 days after intraperitoneal administration of 10 and 20 mg/kg LPS alone, respectively. Intravenously administered antisense oligonucleotide alone did not produce any significant changes in the behavior or lung histology. After intravenous administration of the anti-sense oligonucleotide, both peripheral blood monocytes and alveolar macrophages in bronchoalveolar lavage fluid were confirmed to contain sufficiently large amounts of intracellular antisense oligonucleotides for their function usingfluorescein isothiocyanate (FTCC)-labeled microscopy. The antisense oligonucleotide administered 6 hours before the intraperitoneal administration of LPS significantly decreased the survival rate with the progress of hemorrhagic edema in lung histology; 90% and 100% of animals treated with the antisense oligonuleotide died 0.5 to 1.5 days after the administration of 10 and 20 mg/kg LPS, respectively. These findings suggest that the suppression of cytokines and mediators in monocytes and alveolar macrophages by the antisense oligonucleotide to the p65 subunit of NF-kappaB worsens the survival of LPS-induced ARDS in mice with the progress of hemorrhagic lung edema.