Association of Surfactant-Associated Protein D Gene Polymorphisms with the Risk of COPD: a Meta-Analysis

Unraveling the enigma: The emerging significance of pulmonary surfactant proteins in predicting, diagnosing, and managing COVID-19

BACKGROUND

Severe cases of COVID-19 often lead to the development of acute respiratory syndrome, a critical condition believed to be caused by the harmful effects of SARS-CoV-2 on type II alveolar cells. These cells play a crucial role in producing pulmonary surfactants, which are essential for proper lung function. Specifically focusing on surfactant proteins, including Surfactant protein A (SP-A), Surfactant protein B, Surfactant protein C, and Surfactant protein D (SP-D), changes in the levels of pulmonary surfactants may be a significant factor in the pathological changes seen in COVID-19 infection.

OBJECTIVE

This study aims to gain insights into surfactants, particularly their impacts and changes during COVID-19 infection, through a comprehensive review of current literature. The study focuses on the function of surfactants as prognostic markers, diagnostic factors, and essential components in the management and treatment of COVID-19.

FINDING

In general, pulmonary surfactants serve to reduce the surface tension at the gas-liquid interface, thereby significantly contributing to the regulation of respiratory mechanics. Additionally, these surfactants play a crucial role in the innate immune system within the pulmonary microenvironment. Within the spectrum of COVID-19 infections, a compelling association is observed, characterized by elevated levels of SP-D and SP-A across a range of manifestations from mild to severe pneumonia. The sudden decline in respiratory function observed in COVID-19 patients may be attributed to the decreased synthesis of surfactants by type II alveolar cells.

CONCLUSION

Collectin proteins such as SP-A and SP-D show promise as biomarkers, offering potential avenues for predicting and monitoring pulmonary alveolar injury in the context of COVID-19. This clarification enhances our understanding of the molecular complexities contributing to respiratory complications in severe COVID-19 cases, providing a foundation for targeted therapeutic approaches using surfactants and refined clinical management strategies.

Association between interferon-gamma (IFN-γ) gene polymorphisms and tuberculosis susceptibility: a systematic review and meta-analysis

Interferon-gamma (IFN-γ) has been established to play a pivotal role in the pathogenesis of tuberculosis (TB). Existing evidence suggests a potential association between the genetic poly-morphisms of IFN-γ and the susceptibility to TB. However, this association remains a topic of controversy. To address this knowledge gap, a meta-analysis was conducted to provide more accurate results regarding their relationship. The pooled odds ratio along with its corresponding 95% confidence interval was calculated using four different gene models. This analytical approach served to evaluate the strength of the association between single nucleotide polymorphisms (SNPs) and TB susceptibility. Additionally, we determined whether a fixed effect model or a random effect model should be applied based on the extent of heterogeneity. Egger's test was used to evaluate publication bias. This study included a total of nine studies, involving 4509 patients with TB and 4378 healthy controls. In non-Asian populations, a C > T mutation at polymorphic variant rs2069705 and a T > C mutation at rs2069718 was associated with an increased risk of TB. Conversely, among Asians, the variants rs2069705, rs2069718, and rs1861494 were not significantly associated with the risk of TB. Importantly, our investigation did not reveal any significant publication bias in the pooled results of the four gene models. In conclusion, this meta-analysis suggests that two SNPs in IFN-γ may be associated with TB susceptibility in non-Asian populations. However, for Asians, there is no evidence to support a conclusive relationship between these SNPs and the risk of TB.

Association of Surfactant Protein D Single Nucleotide Polymorphisms rs721917, rs2243639, rs3088308 with Recurrent Aphthous Stomatitis in Pakistani Population

Recurrent aphthous stomatitis (RAS) is a benign ulcerative condition, defined by the recurrent formation of non-contagious mucosal ulcers. Surfactant protein D (SP-D) is secreted frequently at surfaces exposed directly to body fluids. This study aims to investigate the association of SP-D single nucleotide polymorphisms (SNPs) with the onset of RAS. Blood samples from 212 subjects (106 cases/controls each) were collected during 2019 and genotyped for SP-D SNPs (rs721917, rs2243639, rs3088308) by polymerase chain reaction and restriction fragment length polymorphism followed by 12% polyacrylamide gel electrophoresis. Minor aphthous (75.5%) was the commonly observed ulcer type as compared to herpetiform (21.7%) and major aphthous ulcers (2.8%). A family history of RAS was reported in 70% of cases. RAS was found significantly associated with rs3088308 genotypes T/A (95% (Cl): 1.57-5.03, p = 0.0005), A/A (95% (Cl): 1.8-6.7, p = 0.0002), T-allele (95% (Cl): 1.09-2.36, p = 0.01), A-allele (95% (Cl): 1.42-3.91, p = 0.01), rs721917 genotype T/T (95% (Cl): 1.15-25.35, p = 0.03), and T-allele (95% (Cl): 1.28-3.10, p = 0.002). Female gender and obese body mass index (BMI) were significantly associated with rs3088308 genotypes T/A (95% (CI): 1.89-15.7, p = 0.001), T/T (95% (Cl): 1.52-11.9, p = 0.005), A-allele (95% (Cl): 1.65-7.58, p < 0.001), and T-allele (95% (Cl): 1.4-10.1, p <0.001) and rs721917 genotype T/T (95% (CI) = 1.3-33, p = 0.02), respectively. This study describes the association of SP-D SNPs (rs721917, rs3088308) with RAS in the Pakistani population.

Novel Applications of Biomarkers in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an important health problem and an increasing cause of morbidity and mortality worldwide. Currently, COPD is considered a multisystem disease. Although it primarily affects the lungs, structural and functional changes occur in other organs due to systemic inflammation. It is stated that in patients with COPD, airway and systemic inflammatory markers are increased and that these markers are high are associated with a faster decline in lung functions. In recent years, numerous articles have been published on the discovery and evaluation of biomarkers in COPD. Many markers have also been studied to accurately assess COPD exacerbations and provide effective treatment. However, based on the evidence from published studies, a single molecule has not been adequately validated for broad clinical use.

Genetic Variants Associated with Chronic Obstructive Pulmonary Disease Risk: Cumulative Epidemiological Evidence from Meta-Analyses and Genome-Wide Association Studies

Background

Last two decades, many association studies on genetic variants and chronic obstructive pulmonary disease (COPD) risk have been published. But results from different studies are inconsistent. Therefore, we performed this article to systematically evaluate results from previous meta-analyses and genome-wide association studies (GWASs). Material and Methods. Firstly, we retrieved meta-analyses in PubMed, Embase, and China National Knowledge Infrastructure and GWASs in PubMed and GWAS catalog on or before April 7th, 2022. Then, data were extracted and screened. Finally, two main methods—Venice criteria and false-positive report probability test—were used to evaluate significant associations.

Results

As a result, eighty-eight meta-analyses and 5 GWASs were deemed eligible for inclusion. Fifty variants in 26 genes obtained from meta-analyses were significantly associated with COPD risk. Cumulative epidemiological evidence of an association was graded as strong for 10 variants in 8 genes (GSTM1, CHRNA, ADAM33, SP-D, TNF-α, VDBP, HMOX1, and HHIP), moderate for 6 variants in 5 genes (PI, GSTM1, ADAM33, TNF-α, and VDBP), and weak for 40 variants in 23 genes. Five variants in 4 genes showed convincing evidence of no association with COPD risk in meta-analyses. Additionally, 29 SNPs identified in GWASs were proved to be noteworthy based on the FPRP test.

Conclusion

In summary, more than half (52.38%) of genetic variants reported in previous meta-analyses showed no association with COPD risk. However, 13 variants in 9 genes had moderate to strong evidence for an association. This article can serve as a useful reference for further studies.

Association of Human Hedgehog Interacting Protein Gene Polymorphisms with the Risk of Chronic Obstructive Pulmonary Disease: a Meta-Analysis

OBJECTIVE

To date, some studies revealed that HHIP gene polymorphisms may be associated with the risk of chronic obstructive pulmonary disease (COPD). Therefore, this meta-analysis explored the association between single-nucleotide polymorphisms (SNPs) of the human hedgehog interacting protein (HHIP) gene and susceptibility to COPD.

METHODS

Seven Chinese and English electronic databases were searched for eligible studies up to May 30, 2020. After the inclusion criteria were strictly followed, the Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included studies. The pooled odds ratio (OR) of the 95% confidence interval (CI) under four different genetic models was calculated to evaluate the association strength between the SNPs and COPD. Egger's test was used to evaluate publication bias.

RESULTS

This meta-analysis was registered at PROSPERO (CRD42021235708). In total, 12 studies involving 6623 COPD patients and 11373 healthy controls were included. Regarding rs13118928 and rs1828591, an A>G mutation increased the risk of COPD in Asian and Caucasian individuals, and the rs13147758 A>G mutation and rs10519717 C>T mutation increased the risk of COPD only in Asian people. No significant publication bias was observed.

CONCLUSION

This meta-analysis provides a theoretical basis suggesting that HHIP gene polymorphisms may be associated with the risk of COPD.

Overexpression of RNF126 is associated with poor prognosis and contributes to the progression of lung adenocarcinoma

Aim: To document the expression and function of RNF126 in lung adenocarcinoma (LAD). Materials & methods: A total of 102 LAD patients were enrolled in this retrospective study. The mRNA and protein levels of RNF126 were tested via RT-qPCR and immunohistochemical staining, respectively. Univariate and multivariate analyses were conducted to exploring the clinical significance of RNF126 in the prognosis. Knockdown and overexpression strategies were used to validate the tumor-related roles of RNF126 both in vitro and in vivo. Results: RNF126 was highly expressed and was an independent predictor of a poor prognosis for LAD patients. We also revealed that RNF126 knockdown suppressed proliferation of LAD cells and xenografts. Conclusion: RNF126 is a potential survival predictor and therapeutic target for LAD.

Prognostic and Clinicopathological Value of ZWINT Expression Levels in Patients with Lung Adenocarcinoma: A Systematic Review and Meta-analysis

The current study found that high Zeste White 10 interactor (ZWINT) expression is related to the poor prognosis of patients with a variety of cancers. This study mainly explored the relationship between the expression level of ZWINT and the prognosis of patients with lung adenocarcinoma (LUAD). Briefly, four English databases and two high-throughput sequencing databases were searched and relevant data for meta-analysis were extracted. Pooled mean difference and 95% confidence interval (CI) were used to assess the relationships between clinical features and the expression of ZWINT. Pooled hazard ratio and 95% CI were also used to assess the relationships between clinical features and the expression level of ZWINT. This meta-analysis was registered in PROSPERO (CRD42021249475). A total of 16 high-quality datasets comprising 2,847 LUAD patients were included in this study. Higher ZWINT expression levels were found in patients younger than 65 years, males, and smokers, and were correlated with advanced TNM stages and poor prognosis. Notably, there was no publication bias in this meta-analysis. Overall, our findings indicate that ZWINT is a potential biomarker for poor prognosis and clinicopathological outcomes of patients with LUAD.