Tumor Suppressors-HTRA Proteases and Interleukin-12-in Pediatric Asthma and Allergic Rhinitis Patients

Lentivirus-Mediated Missense Mutation in HtrA1 Leads to Activation of the TGF-β/Smads Pathway and Increased Apoptosis of Mouse Brain Microvascular Endothelial Cells via the Oxidative Stress Pathway

BACKGROUND

The aim of this study was to investigate the possible molecular mechanisms underlying cerebral small vessel disease caused by a missense mutation in the high-temperature serine peptidase A1 gene, HtrA1 (NM_002775.4, Exon4, c.905G>A, p.Arg302Gln). Stable strain models were constructed using wild-type and mutant HtrA1 overexpression lentiviral vectors to infect mouse brain microvascular endothelial cells (bEnd.3 cells).

METHODS

HtrA1 mRNA and protein expression were analyzed by Western blot and quantitative real-time polymerase chain reaction. Western blot technique was also used to evaluate the expression of transforming growth factor (TGF)-β/Smads-related signaling pathway proteins and the oxidative stress pathway protein nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). The level of reactive oxygen species (ROS) was evaluated using dichloro-dihydro-fluorescein diacetate (DCFH-DA) fluorescent probes.

RESULTS

HtrA1 mRNA and protein expression levels were found to be decreased in mutant cells, whereas the levels of ROS, the TGF-β/Smads proteins, and the caspase3 and cleaved-caspase3 apoptotic proteins were increased.

CONCLUSIONS

Lentivirus-mediated missense mutation in HtrA1 leads to activation of the TGF-β/Smads pathway and to increased apoptosis of mouse brain microvascular endothelial cells via the oxidative stress pathway. Further in vivo studies are required to explore the connections between different signaling pathways in animals, and to identify potential molecular targets for clinical therapy.

Exploring the Role of HtrA Family Genes in Cancer: A Systematic Review

PURPOSE

HtrA1, HtrA2, HtrA3 and HtrA4 appear to be involved in the development of pathologies such as cancer. This systematic review reports the results of a literature search performed to compare the expression of HtrA family genes and proteins in cancer versus non-cancer tissues and cell lines, assess relationships between HtrA expression and cancer clinical features in cancer, and analyse the molecular mechanism, by which HtrA family affects cancer.

METHODS

The literature search was conducted according to the PRISMA statement among four databases (PubMed, Web of Science, Embase and Scopus).

RESULTS

A total of 38 articles met the inclusion criteria and involved the expression of HtrA family members and concerned the effect of HtrA expression on cancer and metastasis development or on the factor that influences it. Additionally, 31 reports were retrieved manually. Most articles highlighted that HtrA1 and HtrA3 exhibited tumour suppressor activity, while HtrA2 was associated with tumour growth and metastasis. There were too few studies to clearly define the role of the HtrA4 protease in tumours.

CONCLUSION

Although the expression of serine proteases of the HtrA family was dependent on tumour type, stage and the presence of metastases, most articles indicated that HtrA1 and HtrA3 expression in tumours was downregulated compared with healthy tissue or cell lines. The expression of HtrA2 was completely study dependent. The limited number of studies on HtrA4 expression made it impossible to draw conclusions about differences in expression between healthy and tumour tissue. The conclusions drawn from the study suggest that HtrA1 and HtrA3 act as tumour suppressors.

Air pollution exposure is associated with rhinitis in older US adults via specific immune mechanisms

BACKGROUND

Pathophysiology of rhinitis in older adults is largely unknown. We tested whether air pollution is associated with this condition and how immune mechanisms may play a role in this relationship.

METHODS

We analyzed cross-sectional data from the National Social Life, Health, and Aging Project, a nationally representative study of older adults born between 1920 and 1947. Particulate matter ≤2.5 μm (PM2.5 ) air pollution exposure estimates were generated using validated spatiotemporal models. Presence of rhinitis was defined based on medication use (≥1: intranasal medications: steroids, antihistamines, lubricants, and/or decongestants, and/or oral medications: antihistamines and/or decongestants). K-means cluster analysis (Jaccard method) was used to group 13 peripheral blood cytokines into 3 clusters to facilitate functional determination. We fitted multivariate logistic regressions to correlate PM2.5 exposure with presence of rhinitis, controlling for confounders, and then determined the role of cytokines in this relationship.

RESULTS

Long- (but not short-) term exposure to PM2.5 was associated with presence of rhinitis: 3-year exposure window, odds ratio (OR) = 1.32, 95% confidence interval (CI): 0.98, 1.80, per 1 standard deviation (SD) PM2.5 increase. Inclusion of cytokine cluster in the model led to a modestly stronger effect of PM2.5 exposure on rhinitis (OR = 1.37; 95% CI: 1.00, 1.87; 3-year exposure window). The particular immune profile responsible for this result was composed of elevated IL-3, IL-12, and IFN-γ (OR = 4.86, 95% CI: 1.10, 21.58, immune profile-PM2.5 exposure interaction term).

CONCLUSION

We show for the first time that IL-3, IL-12, and IFN-γ explain in part the relationship between PM2.5 exposure and rhinitis in older US adults. If confirmed, these immune pathways may be used as therapeutic targets.