Background: Exposure to air pollution is associated with chronic obstructive pulmonary disease (COPD). However, findings on the effects of air pollution on lung function and systemic inflammation in Chinese COPD patients are inconsistent and scarce. This study aims to evaluate the effects of ambient air pollution on lung function parameters and serum cytokine levels in a COPD cohort in Beijing, China. Methods: We enrolled COPD participants on a rolling basis from December 2015 to September 2017 in Beijing, China. Follow-ups were performed every 3 months for each participant. Serum levels of 20 cytokines were detected every 6 months. Hourly ambient pollutant levels over the same periods were obtained from 35 monitoring stations across Beijing. Geocoded residential addresses of the participants were used to estimate daily mean pollution exposures. A linear mixed-effect model was applied to explore the effects of air pollutants on health in the first-year of follow-up. Results: A total of 84 COPD patients were enrolled at baseline. Of those, 75 COPD patients completed the first-year of follow-up. We found adverse cumulative effects of particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and carbon monoxide (CO) on the forced vital capacity % predicted (FVC % pred) in patients with COPD. Further analyses illustrated that among COPD patients, air pollution exposure was associated with reduced levels of serum eotaxin, interleukin 4 (IL-4) and IL-13 and was correlated with increased serum IL-2, IL-12, IL-17A, interferon γ (IFNγ), monocyte displacing protein 1 (MCP-1) and soluble CD40 ligand (sCD40L). Conclusion: Acute exposures to PM_2.5, NO₂, SO₂ and CO were associated with a reduction in FVC % pred in COPD patients. Furthermore, short-term exposure to air pollutants increased systemic inflammation in COPD patients; this may be attributed to increased Th1 and Th17 cytokines and decreased Th2 cytokines.

The mammalian target of rapamycin (mTOR) signaling pathway in pulmonary fibrosis was investigated in cell and animal models. mTOR overactivation in alveolar epithelial cells (AECs) was achieved in the conditional and inducible Tsc1 knock-down mice SPC-rtTA/TetO-Cre/Tsc1^fx/+ (STT). Doxycycline caused Tsc1 knock-down and consequently mTOR activation in AECs for the STT mice. Mice treated with bleomycin exhibited increased mortality and pulmonary fibrosis compared with control mice. In wild-type C57BL/6J mice, pretreatment with rapamycin attenuated the bleomycin-mediated mortality and fibrosis. Rapamycin-mediated mouse survival benefit was inhibited by chloroquine, an autophagy inhibitor. Autophagosomes were decreased in the lungs after bleomycin exposure. Rapamycin induced the production of autophagosomes and diminished p62. We concluded that mTOR overactivation in AECs and compromised autophagy in the lungs are involved in the pathogenesis of pulmonary fibrosis. The suppression of mTOR and enhancement of autophagy may be used for treatment of pulmonary fibrosis.

This is a study on the role of tuberous sclerosis complex1 (TSC1) mutation and mTOR activation in endothelial cells during angiogenic and embryonic development. Past studies had shown that Tsc1/Tsc2 mutant genes lead to overactivation of mTOR in the regulating pathways in developing fetus. We used conditional Cre-loxp gene knockout approach to delete Tsc1 in mice's endothelial cells in our experimental models. Similarly, activation of mTOR signaling in endothelial cells of these embryos (Tie2-Cre/Tsc1^−/−) was found. Majority of Tie2-Cre/Tsc1^−/− embryos died at embryonic day 14.5 in utero. Cardiovascular defects, subcutaneous edema and hemorrhage were present among them. Whole-mount immunostaining in these embryos revealed a disorganized vascular network, defective sprouting of vessels in yolk sac and thickening of the labyrinth layer in the placenta. A thinner ventricular wall with disorganized trabeculae was present in the hearts of Tie2-Cre/Tsc1^−/− embryos. Endothelial cells in Tsc1-deficient mice showed defective mitochondrial and endoplasmic reticular morphology, but no significant change was observed in cell junctions. The mutant embryos displayed significantly reduced cell proliferation, increased apoptosis and disturbed expression of angiogenic factors. A cohort of mice was treated prenatally with mTOR inhibitor rapamycin. The offspring of these mutant mice survived up to 22 days after birth. It was concluded that physiological TSC1-mTOR signaling in endothelial cells is crucial for vascular development and embryogenesis. We postulated that disruption of normal angiogenic pathways through hyperactive mTOR signaling maybe the mechanism that lead to deranged vascular pathogenesis in the tuberous sclerosis complex.

Summary: Background: The novel coronavirus (CoV) severe acute respiratory syndrome (SARS)-CoV-2 outbreak started at the end of 2019 in Wuhan, China, and spread over 100 countries. SARS-CoV-2 uses the membrane protein Angiotensin I converting enzyme 2(ACE2) as a cell entry receptor. Indeed, it was reported that the balance of Renin-Angiotensin System (RAS), regulated by both ACE and ACE2, was altered in COVID-19 patients. It is controversial, however, whether commonly used anti-hypertensive drugs Angiotensin I converting enzyme inhibitor (ACEI) and Angiotensin II receptor blocker (ARB) shall be continued in the confirmed COVID-19 patients. This study was designed to investigate any difference in disease severity between COVID-19 patients with hypertension comorbidity. The included COVID-19 patients used ACEI, ARB, calcium channel blockers (CCB), beta blockers (BB), or thiazide to treat preexisting hypertension prior to the hospital were compared to patients who did not take any of those drugs. Methods: In this multicentre retrospective study, clinical data of 511 COVID-19 patients were analyzed. Patients were categorized into six sub-groups of hypertension comorbidity based on treatment using one of anti-hypertension drugs (ACEI, ARB, CCB, BB, thiazide), or none. A meta-analysis was performed to evaluate the use of ACEI and ARB associated with pneumonia using published studies. Findings: Among the elderly (age>65) COVID-19 patients with hypertension comorbidity, the risk of COVID-19-S (severe disease) was significantly decreased in patients who took ARB drugs prior to hospitalization compared to patients who took no drugs (OR=0·343, 95% CI 0·128-0·916, p=0·025). The meta-analysis showed that ARB use has positive effects associated with morbidity and mortality of pneumonia. Interpretation: Elderly (age>65) COVID-19 patients with hypertension comorbidity who are taking ARB anti-hypertension drugs may be less likely to develop severe lung disease compared to patients who take no anti-hypertension drugs. Funding: National Natural Science Foundation of China, Chinese Academy of Medical Sciences Research in context: Evidence before this study: We searched PubMed for articles published up to March 15, 2020 using keywords “2019-nCoV”, “SARS-CoV-2”, “novel coronavirus”, and COVID-19 AND “ARB”, and “angiotensin II receptor blocker” for papers published in both English and Chinese. We found three papers: one from our group, published in Science China Life Science that demonstrated an elevated Angiotensin II level in blood samples from COVID-19 patients; another a perspective article in Chinese recommending ACEI and ARBs as potential remedies for SARS-CoV-2 infections; the third a retrospective study in Chinese identifying no significant difference between ACEI/ARB associated with outcomes in 112 COVID-19 patients with CVD comorbidity. The International society of Hypertension stated on March 16 ^th , 2020: “there are no clinical data in human to show that ACE-inhibitors or ARBs either improve or worsen susceptibility to COVID-19 infection nor do they affect the outcomes of those infected”. Added value of this study: We retrospectively reviewed different types of anti-hypertensive drugs taken by COVID-19 patients with hypertension comorbidity prior to entering the hospital. We discovered that ARB hypertensive drugs were associated with a decreased risk of severe disease in elderly (age>65) COVID-19 patients (OR=0·343, 95% CI 0·128-0·916, p=0·025), the first evidence of ARBs association to COVID-19 infections in human. We conducted a meta-analysis in the literature and found that ARB has positive effects associated with morbidity and mortality of pneumonia. Implications of all the available evidence: ARB drugs are widely used in the population with hypertension. Treatments with ACEI and ARBs should be continuous according to medical guidelines. RCT trials of ARB associated with morbidity and mortality of SARS-CoV-2 infection are recommended in the future.

Hydrogen was proven to have anti-oxidative and anti-inflammation effects to various diseases. We wish to investigate the acute effects of inhaled hydrogen on airway inflammation in patients with asthma and chronic obstructive pulmonary disease (COPD). Prospective study. In total, 2.4% hydrogen containing steam mixed gas (XEN) was inhaled once for 45 min in 10 patients with asthma and 10 patients with COPD. The levels of granulocyte-macrophage colony stimulating factor, interferon-γ, interleukin-1β (IL-1β), IL-2, IL-4, IL-6 and so on in peripheral blood and exhaled breath condensate (EBC) before and after ‘XEN’ inhalation were measured. 45 minutes ‘XEN’ inhalation once decreased monocyte chemotactic protein 1 level in both COPD (564.70–451.51 pg/mL, P = 0.019) and asthma (386.39–332.76 pg/mL, P = 0.033) group, while decreased IL-8 level only in asthma group (5.25–4.49 pg/mL, P = 0.023). The level of EBC soluble cluster of differentiation-40 ligand in COPD group increased after inhalation (1.07–1.16 pg/mL, P = 0.031), while IL-4 and IL-6 levels in EBC were significantly lower after inhalation in the COPD (0.80–0.64 pg/mL, P = 0.025) and asthma (0.06–0.05 pg/mL, P = 0.007) group, respectively. A single inhalation of hydrogen for 45 min attenuated inflammatory status in airways in patients with asthma and COPD.