Alterations of gut microbiome in eosinophilic chronic rhinosinusitis.

PURPOSE: A growing body of evidence has elucidated that the gut microbiota has a crucial impact on the pathophysiological process of atopic diseases. Eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP) is a local atopic disease of the systemic immune response. Alterations in the gut microbiome in eCRSwNP patients remain largely undefined. METHODS: 16S rRNA gene sequencing was performed in a cross-sectional study of 17 eCRSwNP patients, 9 noneCRSwNP patients and 13 healthy controls, and gut microbiota DNA sequencing between each pair of groups was compared using bioinformatic methods. RESULTS: Compared with that of healthy controls, the gut microbiomes of eCRSwNP patients were characterised by a distinct overall microbial composition. However, no significant differences were found in the alpha diversity of the gut microbiota between patients and healthy controls. The distinct differences in microbial composition were significantly correlated with the severity of disease. At the genus level, the abundance of Faecalibacterium positively correlated with Lund-Mackay CT scores. Similarly, the abundance of Turicibacter positively correlated with the percentage of tissue eosinophils. CONCLUSIONS: We found alterations in the gut microbiome in eCRSwNP patients, and the alterations in the gut microbiome were correlated with the severity of disease.

Inhalation of hydrogen gas protects against mitomycin-induced pulmonary veno-occlusive disease.

BACKGROUND: As a subtype of pulmonary hypertension (PH), pulmonary veno-occlusive disease (PVOD) is devastating and life-threatening disease without effective therapy. Hydrogen has been reported to exhibits antioxidant and anti-inflammatory effects in a rat model induced by monocrotaline of PH. In this study, we investigated the effects of inhaled hydrogen gas on the prevention and treatment of PVOD induced by mitomycin C (MMC) in rats. METHODS: PVOD was induced in female Sprague-Dawley rats through intraperitoneal injection of MMC at a concentration of 3 mg·kg- 1·wk- 1 for 2 weeks. Inhalation of hydrogen gas (H2) was administered through a designed rat cage concurrently or two weeks after MMC administration. The severity of PVOD was assessed by using hemodynamic measurements and histological analysis. The expression levels of general control nonderepressible 2 (GCN2), nuclear factor erythroid 2-related factor-2 (Nrf2), heme oxygenase-1 (HO-1) and endothelial-to-mesenchymal transition (EndoMT) related proteins in lung tissue were measured. Levels of lipid peroxidation pro-inflammatory cytokines in serum were determined. RESULTS: Inhaled H2 improved hemodynamics and right heart function, reversed right ventricular hypertrophy, and prevented pulmonary vessel reconstitution in both prevention and treatment approaches. It decreased malondialdehyde (MDA) levels in the serum and the expression of NADPH oxidase 1 (NOX-1) in lung tissue. It regulated Nrf2/HO-1 signaling pathway and anti-inflammatory factor GCN2 in lung tissue, accompanied by a decrease in macrophages and pro-inflammatory cytokines. Our data suggested that H2 inhalation effectively countered EndoMT induced by MMC, as evidenced by the detection of endothelial markers (e.g., VE-cadherin and CD31) and mesenchymal markers (e.g., vimentin and fibronectin). Further research revealed that H2 preserved p-Smad3 and induced p-Smad1/5/9. CONCLUSION: Inhalation of H2 effectively inhibits the pathogenesis of PVOD induced by MMC in rats. This inhibitory effect may be attributed to the antioxidant and anti-inflammatory properties of H2.

Nephrectomy and high-salt diet inducing pulmonary hypertension and kidney damage by increasing Ang II concentration in rats.

BACKGROUND: Chronic kidney disease (CKD) is a significant risk factor for pulmonary hypertension (PH), a complication that adversely affects patient prognosis. However, the mechanisms underlying this association remain poorly understood. A major obstacle to progress in this field is the lack of a reliable animal model replicating CKD-PH. METHODS: This study aimed to establish a stable rat model of CKD-PH. We employed a combined approach, inducing CKD through a 5/6 nephrectomy and concurrently exposing the rats to a high-salt diet. The model's hemodynamics were evaluated dynamically, alongside a comprehensive assessment of pathological changes in multiple organs. Lung tissues and serum samples were collected from the CKD-PH rats to analyze the expression of angiotensin-converting enzyme 2 (ACE2), evaluate the activity of key vascular components within the renin-angiotensin-aldosterone system (RAAS), and characterize alterations in the serum metabolic profile. RESULTS: At 14 weeks post-surgery, the CKD-PH rats displayed significant changes in hemodynamic parameters indicative of pulmonary arterial hypertension. Additionally, right ventricular hypertrophy was observed. Notably, no evidence of pulmonary vascular remodeling was found. Further analysis revealed RAAS dysregulation and downregulated ACE2 expression within the pulmonary vascular endothelium of CKD-PH rats. Moreover, the serum metabolic profile of these animals differed markedly from the sham surgery group. CONCLUSIONS: Our findings suggest that the development of pulmonary arterial hypertension in CKD-PH rats is likely a consequence of a combined effect: RAAS dysregulation, decreased ACE2 expression in pulmonary vascular endothelial cells, and metabolic disturbances.

Airway delivery of Streptococcus salivarius is sufficient to induce experimental pulmonary hypertension in rats.

BACKGROUND AND PURPOSE: The causal relationship between altered host microbiome composition, especially the respiratory tract microbiome, and the occurrence of pulmonary hypertension (PH) has not yet been studied. An increased abundance of airway streptococci is seen in patients with PH compared with healthy individuals. This study aimed to determine the causal link between elevated airway exposure to Streptococcus and PH. EXPERIMENTAL APPROACH: The dose-, time- and bacterium-specific effects of Streptococcus salivarius (S. salivarius), a selective streptococci, on PH pathogenesis were investigated in a rat model established by intratracheal instillation. KEY RESULTS: Exposure to S. salivarius successfully induced typical PH characteristics, such as elevated right ventricular systolic pressure (RVSP), right ventricular hypertrophy (Fulton's index) and pulmonary vascular remodelling, in a dose- and time-dependent manner. Moreover, the S. salivarius-induced characteristics were absent in either the inactivated S. salivarius (inactivated bacteria control) treatment group or the Bacillus subtilis (active bacteria control) treatment group. Notably, S. salivarius-induced PH is characterized by elevated inflammatory infiltration in the lungs, in a pattern different from the classic hypoxia-induced PH model. Moreover, in comparison with the SU5416/hypoxia-induced PH model (SuHx-PH), S. salivarius-induced PH causes similar histological changes (pulmonary vascular remodelling) but less severe haemodynamic changes (RVSP, Fulton's index). S. salivarius-induced PH is also associated with altered gut microbiome composition, suggesting potential communication of the lung-gut axis. CONCLUSION AND IMPLICATIONS: This study provides the first evidence that the delivery of S. salivarius in the respiratory tract could cause experimental PH in rats.

Respiratory Microbiome Profile of Pediatric Pulmonary Hypertension Patients Associated With Congenital Heart Disease.

BACKGROUND: Pulmonary hypertension (PH) associated with congenital heart disease (CHD) is the most common type of PH in pediatric patients. The airway microbiome profile in CHD-PH patients remains rarely studied. METHODS: A total of 158 children were recruited for collection of oropharyngeal swabs to sequence the 16S ribosomal RNA (16S rRNA) V3-V4 region of respiratory microbiome, to establish a correlation between these bacterial groups and echocardiography indicators in CHD-PH patients. RESULTS: Bacterial α- and ß-diversity of the airway microbiome indicated a significantly lower richness in the CHD-PH group and compositional differences associated with the specific taxa and their relative abundances in the upper respiratory tract. Principal coordinate analysis showed that the pharynx microbiota composition in the CHD-PH group varied from that in the CHD or control group. The linear discriminant analysis effect size also highlighted an increased presence of Streptococcus and Rothia in pediatric CHD-PH patients. Comparison of microbial composition between pediatric and adult PH patients showed significant differences and separation of microbiota. The correlation between bacterial abundance and transthoracic echocardiography indexes in CHD-associated PH indicated that different groups of microbiomes may be related to different PH grades. CONCLUSIONS: In summary, our study reported the systematic definition and divergent profile of the upper respiratory tract microbiota in pediatric PH patients, CHD and reference subjects, as well as between pediatric and adult PH patients.

Microbiome and metabolome dysbiosis of the gut-lung axis in pulmonary hypertension.

Previous studies have suggested that dysbiosis of the gut microbiota is associated with the development of pulmonary hypertension (PH). In this study, we established a left pulmonary artery ligation (LPAL)-induced PH rat model due to high flow and hemodynamic stress and investigated the association between gut microbiota composition and host metabolome signatures (in both gut and lung tissues) by using multiomics and correlation analysis. The results showed that LPAL successfully induced PH, characterized by increased right ventricular systolic pressure, right ventricular hypertrophy and pulmonary vascular remodelling. Moreover, gut pathological abnormalities were observed in association with dramatic alterations in the gut microbiome and metabolome as well as the lung metabolome. The increased bacterial genus Sporobacter and decreased genera Eubacterium, Eubacteriaceae, Deltaproteobacteria and Desulfovibrio featured the altered gut microbiome in LPAL-PH versus SHAM rats. Moreover, imbalanced abundance of protective metabolites (e.g., butyrate, propionate) and pathogenic metabolites (e.g., proinflammatory mediators) were seen in the gut metabolome of LPAL-PH versus SHAM rats. In addition, the altered gut microbiome strongly correlated with the altered metabolome patterns in both the gut and lung of LPAL-PH rats. In conclusion, this study revealed significant gut dysbiosis in LPAL-PH rats, characterized by altered gut microbiota composition, in association with specific changes in gut and lung metabolome profiles. These findings enriched our understanding of the unique signature of the gut microbiome and the close association of the "gut-lung axis" in LPAL-PH induced by long-term high flow, leading to novel therapeutic, diagnostic or management paradigms for this subtype of PH.

Upregulation of mechanosensitive channel Piezo1 involved in high shear stress-induced pulmonary hypertension.

INTRODUCTION: Piezo1 is an important mechanosensitive channel implicated in vascular remodeling. However, the role of Piezo1 in different types of vascular cells during the development of pulmonary hypertension (PH) induced by high shear stress is largely unknown. MATERIALS AND METHODS: We used a rat PH model established by left pulmonary artery ligation (LPAL, for 2-5 weeks), which mimics the high flow and hemodynamic stress, to study Piezo1 contribution to pulmonary vascular remodeling. RESULTS: Right ventricular systolic pressure (RVSP), a surrogate measure for pulmonary arterial systolic pressure, and right ventricular wall thickness, a measure for right ventricular hypertrophy, were significantly increased in LPAL rats compared with Sham-control (SHAM) rats. Rats in LPAL-5w groups developed remarkable pulmonary vascular remodeling, while phenylephrine-induced contraction and acetylcholine-induced relaxation were both significantly inhibited in these rats. Upregulation of Piezo1, in association with increase in cytosolic Ca2+ concentration ([Ca2+]cyt), was observed in pulmonary arterial smooth muscle cells (PASMCs) from LPAL-2w and LPAL-5w rats in comparison to the SHAM controls. Piezo1 upregulation in PASMCs from LPAL rats was directly related to Yes-associated protein (YAP)/ TEA domain transcription factor 4 (TEAD4). Piezo1 expression was also upregulated in the whole-lung tissue of LPAL rats. The endothelial upregulation of Piezo1 was related to transcriptional regulation by RELA (p65) and lung inflammation. CONCLUSION: The upregulation of Piezo1 in both PASMCs and ECs coordinates with each other via different cell signaling pathways to cause pulmonary vascular remodeling in LPAL-PH rats, providing novel insights into the cell-type specific pathogenic roles of Piezo1 in shear stress-associated experimental PH.

Visibility, wind speed, and dew point temperature are important factors in SARS-CoV-2 transmissibility.

The aim of this study is to provide evidence for the influencing factors of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) virus mutation by determining the impact of geographical and meteorological factors on SARS-CoV-2 transmission, and the different impacts of SARS-CoV-2 variant strains. From January 20 to March 10, 2020, we collected a number of daily confirmed new cases and meteorological factors in all cities and regions in China and Italy affected by the Alpha "variants of concern" (VOC). We also collected the daily confirmed cases of the Delta VOC infection in China and Italy from May 21 to November 30, 2021. The relationships between daily meteorological data and daily verified new cases of SARS-CoV-2 transmission were then investigated using a general additive model (GAM) with a log link function and Poisson family. The results revealed that latitude was substantially connected with daily confirmed new instances of the Alpha VOC, while there was no such correlation with Delta VOC transmission. When visibility is greater than 7 m, the propagation of the Alpha and Delta VOCs in Italy and China can be controlled. Furthermore, greater temperatures and increased wind speed reduce the transmission of the Alpha and Delta VOCs. In conclusion, geographical and meteorological factors play an important role in SARS-CoV-2 transmissibility and should be considered in virus mitigation strategies.

Sodium tanshinone IIA sulfonate enhances the BMP9-BMPR2-Smad1/5/9 signaling pathway in rat pulmonary microvascular endothelial cells and human embryonic stem cell-derived endothelial cells.

BACKGROUND: Recent studies have demonstrated the beneficial effects of STS in treating pulmonary hypertension by inhibiting the pulmonary vascular remodeling and suppressing the abnormally elevated proliferation and migration of PASMCs. However, the roles of STS on pulmonary vascular endothelium remain largely known. METHODS: In this study, we investigated the effects and mechanisms of STS on pulmonary vascular endothelial dysfunction by using a chronic hypoxia-induced pulmonary hypertension (HPH) rat model, as well as in primarily cultured rat PMVECs and human ESC-ECs cell models. RESULTS: Firstly, a 21-day treatment of STS significantly prevents the disease development of HPH by normalizing the right ventricular systolic pressure and right ventricular hypertrophy, improving the cardiac output. Then, STS treatment markedly inhibits the hypoxia-induced medial wall thickening of the distal intrapulmonary arteries. Notably, STS significantly inhibits the hypoxia-induced apoptosis in both the pulmonary endothelium of HPH rats and primarily cultured PMVECs, through the stabilization of BMPR2 protein and protection of the diminished BMP9-BMPR2-Smad1/5/9 signaling pathway. In mechanism, STS treatment retrieves the hypoxic downregulation of BMPR2 by stabilizing the BMPR2 protein, inhibiting the BMPR2 protein degradation via lysosome system, and promoting the plasma membrane localization of BMPR2, all of which together reinforcing the BMP9-induced signaling transduction in both PMVECs and human ESC-ECs. However, these effects are absent in hESC-ECs expressing heterozygous dysfunctional BMPR2 protein (BMPR2+/R899X). CONCLUSION: STS may exert anti-apoptotic roles, at least partially, via induction of the BMP9-BMPR2-Smad1/5/9 signaling transduction in pulmonary endothelium and PMVECs.

Scedosporium apiospermum invasive rhinosinusitis in an elderly patient: diagnosis and treatment.

Scedosporium apiospermum is a ubiquitous organism present in the environment and is rarely identified in rhinosinusitis. We report a case of invasive rhinosinusitis with Scedosporium apiospermum which made a definite diagnosis by metagenomic next-generation sequencing (mNGS) from a biopsy sample. The resection of the Scedosporium apiospermum pathological mass was performed with low-temperature plasma radiofrequency ablation. Six months of continuous oral voriconazole treatment was followed. The patient was asymptomatic with no signs of recurrence during the next 1-year follow-up.

Established pulmonary hypertension in rats was reversed by a combination of a HIF-2α antagonist and a p53 agonist.

BACKGROUND AND PURPOSE: Recent studies reported therapeutic effects of monotherapy with either tumour suppressor p53 (p53) agonist or hypoxia-inducible factor 2α (HIF-2α) antagonist for pulmonary hypertension (PH). This study investigated whether a combined treatment of p53 agonist, Nutlin3a, and HIF-2α antagonist, PT2385, would be more effective than monotherapy, based on the cell type-divergent regulation of p53 in pulmonary arterial smooth muscle cells (PASMC) and endothelial cells (PAEC) in patients and animals with PH. EXPERIMENTAL APPROACH: The SU5416/hypoxia-induced PH (SuHx-PH) rat model was used, along with cultured human PASMC and PAEC. Western blot, RT-PCR, siRNA and immunohistochemical methods were used along with echocardiography and studies with isolated pulmonary arteries. KEY RESULTS: Hypoxia-induced proliferation of PASMC is associated with decreased p53, whereas hypoxia-induced PAEC apoptosis is associated with increased p53, via a HIF-2α-dependent mechanism. Combined treatment with Nutlin3a and PT2385 is more effective by simultaneously inhibiting the hypoxia-induced PASMC proliferation and PAEC apoptosis, overcoming the side-effects of monotherapy. These are (i) Nutlin3a exacerbates hypoxia-induced PAEC apoptosis by inducing p53 in PAEC and (ii) PT2385 inhibits PAEC apoptosis because HIF-2α is predominantly expressed in PAEC but lacks direct effects on the hypoxia-induced PASMC proliferation. In rats, combination treatment is more effective than monotherapy in reversing established SuHx-PH, especially in protecting pulmonary arterial vasculature, by normalizing smooth muscle thickening, protecting against endothelial damage and improving function. CONCLUSION AND IMPLICATIONS: Combination treatment confers greater therapeutic efficacy against PH through a selective modulation of p53 and HIF-2α in PASMC and PAEC.

Upregulation of Piezo1 (Piezo Type Mechanosensitive Ion Channel Component 1) Enhances the Intracellular Free Calcium in Pulmonary Arterial Smooth Muscle Cells From Idiopathic Pulmonary Arterial Hypertension Patients.

[Figure: see text].

Dysregulation of BMP9/BMPR2/SMAD signalling pathway contributes to pulmonary fibrosis and pulmonary hypertension induced by bleomycin in rats.

BACKGROUND AND PURPOSE: Pulmonary hypertension related to pulmonary fibrosis is classed as WHO Group III, one of the most common groups which lacks effective treatment options. In this study, we aimed to uncover the underlying mechanisms, particularly the involvement of the BMP9/BMPR2/SMAD signalling pathway, in this subtype of pulmonary hypertension. EXPERIMENTAL APPROACH: Male Sprague Dawley rats were used to establish a model of pulmonary hypertension with pulmonary fibrosis, induced by bleomycin. Haemodynamic and lung functions were measured, along with histological and immunohistochemical examinations. Primary cultures of rat pulmonary microvascular endothelial cells (PMVECs) were analysed with western blots, apoptosis assays and immunohistochemistry. KEY RESULTS: Early (7 days) after bleomycin treatment of rats, pulmonary arterial thickening and severe loss of pulmonary arterial endothelium were observed, followed (14 days) by increased right ventricular systolic pressure and right ventricular hypertrophy. Marked down-regulation of the BMP9/BMPR2/SMAD signalling pathway was markedly down-regulated in lung tissues from bleomycin-treated rats (throughout the 7- to 35-day treatment period) and bleomycin-treated rat PMVECs, along with excessive cell apoptosis and loss of pulmonary arterial endothelium. Treatment with recombinant human bone morphogenetic protein 9 (rhBMP9) attenuated these aspects of bleomycin-induced pulmonary hypertension, by restoring disrupted BMP9/BMPR2/SMAD signalling. CONCLUSION AND IMPLICATIONS: In bleomycin-treated rats, early and persisting suppression of the BMP9/BMPR2/SMAD signalling pathway triggered severe loss of pulmonary arterial endothelium and subsequent pulmonary arterial vascular remodelling, contributing to the development of pulmonary hypertension. Therapeutic approaches reinforcing BMP9/BMPR2/SMAD signalling might be ideal strategies for this subtype of pulmonary hypertension. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Mitomycin C induces pulmonary vascular endothelial-to-mesenchymal transition and pulmonary veno-occlusive disease via Smad3-dependent pathway in rats.

BACKGROUND AND PURPOSE: Pulmonary veno-occlusive disease (PVOD) is a rare disease characterized by the obstruction of small pulmonary veins leading to pulmonary hypertension. However, the mechanisms underlying pulmonary vessel occlusion remain largely unclear. EXPERIMENTAL APPROACH: A mitomycin C (MMC)-induced PVOD rat model was used as in vivo animal model, and primarily cultured rat pulmonary microvascular endothelial cells (PMVECs) were used as in vitro cell model. KEY RESULTS: Our data suggested an endothelial-to-mesenchymal transition (EndoMT) may be present in the pulmonary microvessels isolated from either PVOD patients or MMC-induced PVOD rats. In comparison to the control vessels, vessels from both PVOD patients and PVOD rats had co-localized staining of specific endothelial marker von Willebrand factor (vWF) and mesenchymal marker α-smooth muscle actin (α-SMA), suggesting the presence of cells that co-express endothelial and mesenchymal markers. In both the lung tissues of MMC-induced PVOD rats and MMC-treated rat PMVECs there were decreased levels of endothelial markers (e.g. VE-cadherin and CD31) and increased mesenchymal markers (e.g. vimentin, fibronectin and α-SMA) were detected indicating EndoMT. Moreover, MMC-induced activation of the TGFß/Smad3/Snail axis, while blocking this pathway with either selective Smad3 inhibitor (SIS3) or small interfering RNA (siRNA) against Smad3, dramatically abolished the MMC-induced EndoMT. Notably, treatment with SIS3 remarkably prevented the pathogenesis of MMC-induced PVOD in rats. CONCLUSIONS AND IMPLICATIONS: Our data indicated that targeted inhibition of Smad3 leads to a potential, novel strategy for PVOD therapy, likely by inhibiting the EndoMT in pulmonary microvasculature.

Altered Airway Microbiota Composition in Patients With Pulmonary Hypertension.

Alteration in microbiota composition of respiratory tract has been reported in the progression of many chronic lung diseases, yet, the correlation and causal link between respiratory tract microbiota and the disease development of pulmonary hypertension (PH) remain largely unknown. This study aims to define and compare the respiratory microbiota composition in pharyngeal swab samples between patients with PH and reference subjects. A total of 118 patients with PH and 79 reference subjects were recruited, and the pharyngeal swab samples were collected to sequence the 16S ribosomal RNA (16S rRNA) V3-V4 region of respiratory microbiome. The relative abundances in patients with PH were profoundly different from reference subjects. The Ace and Sobs indexes indicated that the microbiota richness of pharynx value is significantly higher; while the community diversity value is markedly lower in patients with PH, comparing to those of the reference subjects. The microbiota on pharynx showed a different profile between the 2 groups by principal component analysis. The linear discriminant analysis effect size also revealed a significantly higher proportion of Streptococcus, Lautropia, and Ralstonia in patients with PH than reference subjects. The linear discriminant analysis effect size output, which represents the microbial gene functions, suggest genes related to bacterial invasion of epithelial cells, bacterial toxins were enhanced, while genes related to energy metabolism, protein digestion and absorption, and cell division pathways were attenuated in patients with PH versus reference subjects. In summary, our study reports the first systematic definition and divergent profile of the upper respiratory tract microbiota between patients with PH and reference subjects.

Catalytic pyrolysis of tire waste: Impacts of biochar catalyst on product evolution.

Tire scrap is a solid waste that can be potentially used as the feedstock for the production of liquid fuels via the thermochemical process such as catalytic pyrolysis. Nevertheless, it remains challenging to develop the efficient while cost-effective catalyst for the catalytic pyrolysis of tire. In this study, the pyrolysis of tire scrap at 500 °C with the biochar produced from the gasification of poplar wood at 850 °C were conducted. The biochar catalyst significantly affected the evolution of the volatiles and the char properties, while had a slight impact on the yields of the gas, tar and char products. The biochar catalyst catalyzes the cracking of limonene, a major liquid product in tar, to form significantly more propane in gases and alkanes or alkenes in the tar. In addition, the interaction between the biochar with the oxygen-containing organics promoted the re-condensation reaction, which increased the oxygen content in the char, but the biochar catalyst did not influence the evolution of the aromatics. Additionally, the catalytic pyrolysis also makes the biochar catalyst more oxygen-deficient and more resistant towards oxidation. Concluding all the results showed that biochar, which were produced from the gasification of poplar wood can be a potential catalyst for the pyrolysis of tire.

BRIP1 rs10744996C>A variant increases the risk of chronic obstructive pulmonary disease in the Mongolian population of northern China.

NEW FINDINGS: What is the central question of this study? What is the role of breast cancer type 1 interacting protein C-terminal helicase 1 (BRIP1) polymorphism in chronic obstructive pulmonary disease (COPD)? What is the main finding and its importance? Variant rs10744996C>A of BRIP1 increases the susceptibility of the Mongolian population to COPD. The expression of BRIP1 was significantly reduced in cigarette smoke extract-treated airway epithelial cells. ABSTRACT: Cigarette smoke is a major environmental pollutant that can induce DNA damage in humans. The development and progression of chronic obstructive pulmonary disease (COPD) are known to be related to the impairment of DNA repair. Breast cancer type 1 interacting protein C-terminal helicase 1 (BRIP1) plays an important role in DNA interstrand crosslink repair and double-strand break repair. However, the role of BRIP1 polymorphisms in COPD has not been previously described. In this study, whole genome sequencing was used to identify mutations, and single nucleotide polymorphism (SNP) genotyping was used to verify the selected SNPs. In addition the BRIP1 expression levels in 16HBE and A549 airway epithelial cells treated with or without cigarette smoke extract (CSE) were measured using western blotting and RT-qPCR. Rs10744996C>A in the 3'-untranslated region (3'UTR) of BRIP1 was then genotyped in 1296 COPD cases and 988 healthy control subjects from a Mongolian population in northern China. Significant differences in the distribution of rs10744996C>A variants between COPD and control groups (P = 0.001) were identified. Rs10744996C>A was found to be associated with significantly increased COPD risk (adjusted odds ratio = 1.60, 95% CI = 1.30-1.98, P < 0.0001). Additionally, rs10744996A genotype was found to interact with a family history of cancer and a history of x-ray exposure (P = 0.028 and 0.009, respectively). BRIP1 expression levels in 16HBE and A549 cells treated with CSE were significantly lower compared to the control treated cells. The rs10744996C>A variant of BRIP1 increased the COPD susceptibility of the Mongolian population cohort. BRIP1 mRNA and protein expression levels were significantly reduced in conjunction with CSE-induced DNA damage in 16HBE and A549 cells.