Variation in the TEK gene is not associated with asthma but with allergic conjunctivitis

Targeting the Angiopoietin/Tie Pathway: Prospects for Treatment of Retinal and Respiratory Disorders

Anti-angiogenic approaches have significantly advanced the treatment of vascular-related pathologies. The ephemeral outcome and known side effects of the current vascular endothelial growth factor (VEGF)-based anti-angiogenic treatments have intensified research on other growth factors. The angiopoietin/Tie (Ang/Tie) family has an established role in vascular physiology and regulates angiogenesis, vascular permeability, and inflammatory responses. The Ang/Tie family consists of angiopoietins 1-4, their receptors, tie1 and 2 and the vascular endothelial-protein tyrosine phosphatase (VE-PTP). Modulation of Tie2 activation has provided a promising outcome in preclinical models and has led to clinical trials of Ang/Tie-targeting drug candidates for retinal disorders. Although less is known about the role of Ang/Tie in pulmonary disorders, several studies have revealed great potential of the Ang/Tie family members as drug targets for pulmonary vascular disorders as well. In this review, we summarize the functions of the Ang/Tie pathway in retinal and pulmonary vascular physiology and relevant disorders and highlight promising drug candidates targeting this pathway currently being or expected to be under clinical evaluation for retinal and pulmonary vascular disorders.

Distribution of serum specific IgE in children with allergic conjunctivitis and analysis of its concomitant allergic diseases

BACKGROUND

Allergic conjunctivitis (AC) is predominantly caused by serum specific-IgE (sIgE)-mediated type I allergy. This study aims to analyze the distribution of sIgE in children with AC, and the concomitant allergic diseases.

METHODS

The clinical data from 310 children, diagnosed with AC and admitted to our hospital from January 2017 to January 2019 were retrospectively collected. The children were divided into three groups: infant group (2 months to 1 year old, 91 cases), child group (1 to 3 years old, 112 cases), and preschool group (3 to 6 years old, 107 cases). Children in every group were analyzed for positive rates, the number of positive sIgE types, the distribution of positive inhaling and ingesting allergens and concomitant allergic diseases.

RESULTS

The sIgE positive rate of infant was significantly lower than that of the other two groups, and the number of 18.75% sIgE positive species was 1. The number of sIgE positive species in the child group and preschool group was more than 2 (78.30%, 71.15%). The positive rate of sIgE to dust mites, house dust, animal dander, eggs, beef, mutton and mango in the preschool group was significantly higher than the other groups (P<0.05). The positive rate of sIgE to milk in infant group was significantly higher than the other two groups (P<0.05). Children in the preschool group showed the highest incidence of AC, AC + allergic rhinitis, AC + allergic rhinitis + wheezing, while those in the infant group displayed the lowest incidence (P<0.05). AC + gastrointestinal allergy, AC + atopic dermatitis, AC + gastrointestinal allergy + atopic dermatitis in infant group was significantly higher than the other two groups (P<0.05). Patients in the child group displayed a significantly higher incidence of AC + infant wheezing than the other two groups (P<0.05).

CONCLUSIONS

We correlated children's age with the positive rate and gradual increase in types of AC allergens. Concomitant allergic diseases of children with AC at different ages conform to the natural course of allergic diseases. In clinic, improving the diagnostic efficiency of AC in children, and early interventional treatment will positively contribute to their prognosis, and reduce the risk of other allergic diseases.

Identification of TIE2 as a susceptibility gene for neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

PURPOSE

The endothelial and cell-specific angiopoietin-Tie pathway plays an important regulatory role in angiogenesis. In this study, we investigated the associations of the TIE2 (tyrosine kinase, endothelial, TEK) gene with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV), using haplotype-tagging single-nucleotide polymorphisms (SNPs) analysis.

METHODS

This study involved totally 2343 subjects, including a Hong Kong Chinese cohort (214 nAMD patients, 236 PCV patients and 433 control subjects), a Shantou Chinese cohort (189 nAMD patients, 187 PCV patients and 531 control subjects) and an Osaka Japanese cohort (192 nAMD patients, 204 PCV patients and 157 control subjects). Thirty haplotype-tagging SNPs in TIE2 were genotyped in the Hong Kong cohort using TaqMan technology. Two SNPs (rs625767 and rs2273717) showing association in the Hong Kong cohort were genotyped in the Shantou and Osaka cohorts. The SNP-disease association of individual and pooled cohorts were analysed.

RESULTS

Two SNPs (rs625767 and rs2273717) showed suggestive association with both nAMD and PCV in the Hong Kong cohort. In the meta-analysis involving all the three cohorts, rs625767 showed significant associations with nAMD (p=0.01; OR=0.82, 95% CI 0.70 to 0.96; I²=0%), PCV (p=0.02; OR=0.83, 95% CI 0.71 to 0.97; I²=27%) and pooled nAMD and PCV (p=0.002; OR=0.82, 95% CI 0.72 to 0.93; I²=0%), with low inter-cohort heterogeneities.

CONCLUSION

This study revealed TIE2 as a novel susceptibility gene for nAMD and PCV in Japanese and Chinese. Further studies in other populations are warranted to confirm its role.

Investigation of the Possible Role of Tie2 Pathway and TEK Gene in Asthma and Allergic Conjunctivitis

Tie2, coded by the TEK gene, is a tyrosine kinase receptor and plays a central role in vascular stability. It was suggested that variations in the TEK gene might influence the susceptibility to asthma and allergic conjunctivitis. The aim of this study was to further investigate these suggestions, involving different populations and to study the Tie2 related pathway on a mouse model of asthma. The discovery, stage I cohort involved 306 patients with moderate and severe allergic rhinitis, the stage II study consisted of four cohorts, namely, adult and pediatric asthmatics and corresponding controls. Altogether, there were 1,258 unrelated individuals in these cohorts, out of which 63.9% were children and 36.1% were adults. In stage I, 112 SNPs were screened in the TEK gene of the patients in order to search for associations with asthma and allergic conjunctivitis. The top associated SNPs were selected for association studies on the replication cohorts. The rs3824410 SNP was nominally associated with a reduced risk of asthma in the stage I cohort and with severe asthma within the asthmatic population (p=0.009; OR=0.48) in the replication cohort. In the stage I study, 5 SNPs were selected in conjunctivitis. Due to the low number of adult patients with conjunctivitis, only children were involved in stage II. Within the asthmatic children, the rs622232 SNP was associated with conjunctivitis in boys in the dominant model (p=0.004; OR=4.76), while the rs7034505 showed association to conjunctivitis in girls (p=0.012; OR=2.42). In the lung of a mouse model of asthma, expression changes of 10 Tie2 pathway-related genes were evaluated at three points in time. Eighty percent of the selected genes showed significant changes in their expressions at least at one time point during the process, leading from sensitization to allergic airway inflammation. The expressions of both the Tek gene and its ligands showed a reduced level at all time points. In conclusion, our results provide additional proof that the Tie2 pathway, the TEK gene and its variations might have a role in asthma and allergic conjunctivitis. The gene and its associated pathways can be potential therapeutic targets in both diseases.