Background Chronic obstructive pulmonary disease (COPD) and hyperuricaemia are both characterised by systemic inflammation. Preventing chronic diseases among the population with common metabolic abnormality is an effective strategy. However, the association of hyperuricaemia with the higher incidence and risk of COPD remains controversial. Therefore, replicated researches in populations with distinct characteristics or demographics are compellingly warranted.Methods This cohort study adopted a design of ambispective hospital-based cohort. We used propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) to minimise the effects of potential confounding factors. A Cox regression model and restricted cubic spline (RCS) model were applied further to assess the effect of serum urate on the risk of developing COPD. Finally, we conducted a two-sample Mendelian randomisation (MR) analysis to explore evidence of causal association.Results There is a higher incidence in the population with hyperuricaemia compared with the population with normal serum urate (22.29/1000 person-years vs 8.89/1000 person-years, p=0.009). This result is robust after performing PSM (p=0.013) and IPTW (p<0.001). The Cox model confirms that hyperuricaemia is associated with higher risk of developing COPD (adjusted HR=3.35 and 95% CI=1.61 to 6.96). Moreover, RCS shows that the risk of developing COPD rapidly increases with the concentration of serum urate when it is higher than the reference (420 µmol/L). Finally, in MR analysis, the inverse variance weighted method evidences that a significant causal effect of serum urate on COPD (OR=1.153, 95% CI=1.034 to 1.289) is likely to be true. The finding of MR is robust in the repeated analysis using different methods and sensitivity analysis.Conclusions Our study provides convincing evidence suggesting a robust positive association between serum urate and the risk of developing COPD, and indicates that the population with hyperuricaemia is at high risk of COPD in the Chinese population who seek medical advice or treatment in the hospital.

Background: The occurrence and development of chronic obstructive pulmonary disease (COPD) are regulated by environmental and genetic factors. In hypoxia, Erythropoietin (EPO) satisfies the body's need for oxygen by promoting the production of red blood cells. Hypoxia was proven to be a common physiological condition in COPD progression and associated with many complications. Some studies have found that EPO is involved in the development of COPD. But the mechanism has not been fully proven. Methods: We conducted a case-control study enrolled 1095 COPD patients and 1144 healthy controls in Guangdong Province to evaluate the association between EPO polymorphisms (rs1617640 A>C, rs507392 A>G, rs564449 G>T) and COPD susceptibility. 872 participants from southern Gansu Province were recruited to verify the effect of EPO polymorphisms on lung function. Results: EPO rs1617640 C allele reduced COPD susceptibility in southern Chinese significantly (AC vs. AA: adjusted Odds ratio (OR) = 0.805, 95% CI = 0.669-0.969; AC+CC vs. AA: adjusted OR = 0.822, 95% CI = 0.689-0.980). However, there was no association between rs507392 A>G and rs564449 G>T polymorphisms and COPD susceptibility (p > 0.05). We further observed that the rs1617640 C allele was associated with higher FEV1 and FVC in Guangdong and Gansu populations significantly (both p < 0.05). In brief, the level of FEV1 and FVC increased with the C allele number. We modeled the relative risk for men and women, in which the population-attributable risks chances were 0.449 (0.258-0.641) and 0.262 (0.128-0.396) respectively. In this model, smoking status, coal as fuels, education level, and rs1617640 A>C were finally retained for males, while smoking status, biomass as fuels, and1617640 A>C were retained for females. In the end, using the method developed by Gail and Bruzzi, we fitted a 10-year absolute risk model for southern Chinese with different individual relative risks, which was presented as a table. Conclusions: In conclusion, this study found that EPO rs1617640 A>C polymorphism is associated with COPD susceptibility in southern Chinese, and the C allele was associated with better lung function. In addition, it could also be considered a genetic marker associated with environmental factors to predict the absolute 10-year risk of COPD in southern Chinese.

Objective: COPD is the most common chronic respiratory disease with complex environmental and genetic etiologies. It was reported that EPAS1 might participate in the occurrence and development of respiratory diseases. However, the association between EPAS1 and COPD was unclear.Methods: First, a case-control study enrolling 1130 COPD patients and 1115 healthy controls in Guangzhou was conducted to clarify the association between EPAS1 polymorphisms and COPD susceptibility. Secondly, a prevalence study recruited 882 participants in Gansu to verify the effect of positive polymorphisms on lung function. Finally, the 10-year absolute risk considering environmental factors and genetic variations was calculated by the method of Gail and Bruzzi. Results: EPAS1 rs13419896 AA genotype reduced COPD risk in southern Chinese (AA vs. GG: adjusted OR = 0.689, 95% CI = 0.498-0.955; AA vs. GG/GA: adjusted OR = 0.701, 95% CI = 0.511-0.962). Further, the rs13419896 A allele was significantly associated with higher preFEV1/pre-FVC in both the Guangzhou and Gansu populations (P < 0.05). Smoking status, coal as fuels, education level, and rs13419896 G > A were finally retained to develop a relative risk model for males. Smoking status, biomass as fuels, and rs13419896 G > A were retained in the female model. The population-attributable risk of the male or female model was 0.457 (0.283-0.632) and 0.421 (0.227-0.616), respectively.Conclusions: This study first revealed that EPAS1 rs13419896 G > A decreased COPD susceptibility and could be a genetic marker to predict the 10-year absolute risk for COPD.

Receptor-interacting protein kinase 3 (RIPK3) functions as a central regulator of necroptosis, mediating signaling transduction to activate pseudokinase mixed lineage kinase domain-like protein (MLKL) phosphorylation. Increasing evidences show that RIPK3 contributes to the pathologies of inflammatory diseases including multiple sclerosis, infection and colitis. Here, we identified a novel small molecular compound Salt-inducible Kinases (SIKs) inhibitor HG-9-91-01 inhibiting necroptosis by targeting RIPK3 kinase activity. We found that SIKs inhibitor HG-9-91-01 could block TNF- or Toll-like receptors (TLRs)-mediated necroptosis independent of SIKs. We revealed that HG-9-91-01 dramatically decreased cellular activation of RIPK3 and MLKL. Meanwhile, HG-9-91-01 inhibited the association of RIPK3 with MLKL and oligomerization of downstream MLKL. Interestingly, we found that HG-9-91-01 also trigger RIPK3-RIPK1-caspase 1-caspase 8-dependent apoptosis, which activated cleavage of GSDME leading to its dependent pyroptosis. Mechanistic studies revealed that SIKs inhibitor HG-9-91-01 directly inhibited RIPK3 kinase activity to block necroptosis and interacted with RIPK3 and recruited RIPK1 to activate caspases leading to cleave GSDME. Importantly, mice pretreated with HG-9-91-01 showed resistance to TNF-induced systemic inflammatory response syndrome. Consistently, HG-9-91-01 treatment protected mice against Staphylococcus aureus-mediated lung damage through targeting RIPK3 kinase activity. Overall, our results revealed that SIKs inhibitor HG-9-91-01 is a novel inhibitor of RIPK3 kinase and a potential therapeutic target for the treatment of necroptosis-mediated inflammatory diseases.