Molecular Mechanisms of Alu and LINE-1 Interspersed Repetitive Sequences Reveal Diseases of Visual System Dysfunction

BACKGROUND

Short interspersed nuclear elements (SINEs) and long interspersed nuclear elements (LINE-1s) are the abundant and well-characterized repetitive elements in the human genome.

METHODS

For this review, all relevant original research studies were assessed by searching electronic databases, including PubMed, Google Scholar, and Web of Science, by using relevant keywords. Accumulating evidence indicates that the disorder of gene expression regulated by these repetitive sequences is one of the causes of the diseases of visual system dysfunction, including retinal degenerations, glaucoma, retinitis punctata albescens, retinitis pigmentosa, geographic atrophy, and age-related macular degeneration, suggesting that SINEs and LINE-1s may have great potential implications in ophthalmology.

RESULTS

Alu elements belonging to the SINEs are present in more than one million copies, comprising 10% of the human genome.

CONCLUSION

This study offers recent advances in Alu and LINE-1 mechanisms in the development of eye diseases. The current study could advance our knowledge of the roles of SINEs and LINE-1s in the developing process of eye diseases, suggesting new diagnostic biomarkers, therapeutic strategies, and significant points for future studies.

Metabolomic phenotyping of obesity for profiling cardiovascular and ocular diseases

BACKGROUND

We aimed to evaluate the impacts of metabolomic body mass index (metBMI) phenotypes on the risks of cardiovascular and ocular diseases outcomes.

METHODS

This study included cohorts in UK and Guangzhou, China. By leveraging the serum metabolome and BMI data from UK Biobank, this study developed and validated a metBMI prediction model using a ridge regression model among 89,830 participants based on 249 metabolites. Five obesity phenotypes were obtained by metBMI and actual BMI (actBMI): normal weight (NW, metBMI of 18.5-24.9 kg/m²), overweight (OW, metBMI of 25-29.9 kg/m²), obesity (OB, metBMI ≥ 30 kg/m²), overestimated (OE, metBMI-actBMI > 5 kg/m²), and underestimated (UE, metBMI-actBMI < - 5 kg/m²). Additional participants from the Guangzhou Diabetes Eye Study (GDES) were included for validating the hypothesis. Outcomes included all-cause and cardiovascular (CVD)-cause mortality, as well as incident CVD (coronary heart disease, heart failure, myocardial infarction [MI], and stroke) and age-related eye diseases (age-related macular degeneration [AMD], cataracts, glaucoma, and diabetic retinopathy [DR]).

RESULTS

In the UKB, although OE group had lower actBMI than NW group, the OE group had a significantly higher risk of all-cause mortality than those in NW prediction group (HR, 1.68; 95% CI 1.16-2.43). Similarly, the OE group had a 1.7-3.6-fold higher risk than their NW counterparts for cardiovascular mortality, heart failure, myocardial infarction, and coronary heart disease (all P < 0.05). In addition, risk of age-related macular denegation (HR, 1.96; 95% CI 1.02-3.77) was significantly higher in OE group. In the contrast, UE and OB groups showed similar risks of mortality and of cardiovascular and age-related eye diseases (all P > 0.05), though the UE group had significantly higher actBMI than OB group. In the GDES cohort, we further confirmed the potential of metabolic BMI (metBMI) fingerprints for risk stratification of cardiovascular diseases using a different metabolomic approach.

CONCLUSIONS

Gaps of metBMI and actBMI identified novel metabolic subtypes, which exhibit distinctive cardiovascular and ocular risk profiles. The groups carrying obesity-related metabolites were at higher risk of mortality and morbidity than those with normal health metabolites. Metabolomics allowed for leveraging the future of diagnosis and management of 'healthily obese' and 'unhealthily lean' individuals.

The Burden of and Factors Associated with Age-Related Eye Diseases in Arab American Adults

To estimate the age- and sex-adjusted proportions of cataract, diabetic retinopathy, glaucoma, and macular degeneration among the Arab American community, a notably understudied minority that is aggregated under whites. The Arab American Eye Study is a multicenter retrospective chart review involving 10 years of electronic medical records (1/1/2010 through 1/1/2020). The study sample included 1390 Arab Americans and 4950 whites 45 years of age and older, totaling 6340 subjects. Arab Americans were identified using an Arab American name algorithm. Subjects with race variables other than white or Arab American or those under age 45 were excluded from the study. Age- and sex-adjusted proportions of cataract, diabetic retinopathy, glaucoma, and macular degeneration were determined. Odds ratios with 95% confidence intervals were used to examine the association between race/ethnicity and eye diseases. Of the 6340 participants (4950 whites and 1390 Arab Americans), males comprised 46.3% and the median age group was 55-64 years. Arab Americans displayed higher age- and sex-adjusted proportions of cataracts (45.4% versus 40.7%), dry age-related macular degeneration (10% versus 8.9%), glaucoma (8% vs 6%), and diabetic retinopathy (11.7% versus 4.2%). Fully adjusted logistic regression revealed that Arab Americans were 19% more likely to have cataracts (OR 1.19; 95% CI 1.05, 1.35) and 272% more likely to have diabetic retinopathy (OR 2.72; 95% CI 2.17; 3.41). Results from the Arab American Eye Study suggest that the burden of cataract and diabetic retinopathy is significantly higher among Arab Americans in comparison to whites.