Retinal vessels as a window on amyotrophic lateral sclerosis pathophysiology: A systematic review.

Amyotrophic lateral sclerosis (ALS) is a rare fatal motor neuron disease. Although many potential mechanisms have been proposed, the pathophysiology of the disease remains unknown. Currently available treatments can only delay the progression of the disease and prolong life expectancy by a few months. There is still no definitive cure for ALS, and the development of new treatments is limited by a lack of understanding of the underlying biological processes that trigger and promote neurodegeneration. Several scientific results suggest a neurovascular impairment in ALS providing perspectives for the development of new biomarkers and treatments. In this article, we performed a systematic review using PRISMA guidelines including PubMed, EmBase, GoogleScholar, and Web of Science Core Collection to analyze the scientific literature published between 2000 and 2021 discussing the neurocardiovascular involvement and ophthalmologic abnormalities in ALS. In total, 122 articles were included to establish this systematic review. Indeed, microvascular pathology seems to be involved in ALS, affecting all the neurovascular unit components. Retinal changes have also been recently highlighted without significant alteration of the visual pathways. Despite the peripheral location of the retina, it is considered as an extension of the central nervous system (CNS) as it displays similarities to the brain, the inner blood-retinal barrier, and the blood-brain barrier. This suggests that the eye could be considered as a 'window' into the brain in many CNS disorders. Thus, studying ocular manifestations of brain pathologies seems very promising in understanding neurodegenerative disorders, mainly ALS. Optical coherence tomography angiography (OCT-A) could therefore be a powerful approach for exploration of retinal microvascularization allowing to obtain new diagnostic and prognostic biomarkers of ALS.

DNA methylome-wide alterations associated with estrogen receptor-dependent effects of bisphenols in breast cancer.

BACKGROUND: Bisphenol A (BPA), an estrogen-like endocrine disruptor used in plastics, has been associated with development and promotion of breast cancer, so plastic manufacturers shifted towards less-studied analogs, BPF and BPS. Studying the associated DNA methylome-wide mechanisms of these derivatives is timely, particularly in comparison with BPA. METHODS: We assessed proliferation, cell cycle, and migration of breast cancer cells (estrogen receptor (ER)-positive: MCF-7 and ER-negative: MDA-MB-231) treated with BPF and BPS ± estrogen receptor inhibitor (ERI) in comparison to BPA ± ERI. RNA expression and activity of DNA (de)methylation enzymes and LINE-1 methylation were quantified. DNA methylome-wide analysis was evaluated in bisphenol-exposed cells and compared to clinical breast cancer data. RESULTS: The three bisphenols caused ER-dependent increased proliferation and migration of MCF-7 but not MDA-MB-231 cells, with BPS being 10 times less potent than BPA and BPF. Although they have similar chemical structures, the three bisphenols induced differential DNA methylation alterations at several genomic clusters of or single CpG sites, with the majority of these being ER-dependent. At equipotent doses, BPA had the strongest effect on the methylome, followed by BPS then BPF. No pathways were enriched for BPF while BPA- and BPS-induced methylome alterations were enriched in focal adhesion, cGMP-PKG, and cancer pathways, which were also dysregulated in methylome-wide alterations comparing ER-positive breast cancer samples to adjacent normal tissues. CONCLUSIONS: The three bisphenols have important epigenetic effects in breast cell lines, with those of BPA and BPS overlapping with cancer-related pathways in clinical breast cancer models. Hence, further investigation of their safety is warranted.

BPA exposure is associated with non-monotonic alteration in ESR1 promoter methylation in peripheral blood of men and shorter relative telomere length in peripheral blood of women.

The aim of this study was to evaluate the potential association of urinary Bisphenol A (BPA) levels with estrogen receptor alpha (ESR1) promoter % methylation and relative telomere length in a sample of 482 participants. Urinary BPA concentration was measured using organic phase extraction followed by high performance liquid chromatography mass spectroscopy. Peripheral blood ESR1 promoter % methylation and relative telomere length were measured using direct bisulfite sequencing and real-time polymerase chain reaction, respectively. The mean ± SD urinary BPA concentration adjusted for urinary creatinine was 2.90 ± 4.81 (µg/g creatinine) with a median of 1.86 µg/g creatinine (min-max:

CYP2R1 polymorphisms are important modulators of circulating 25-hydroxyvitamin D levels in elderly females with vitamin insufficiency, but not of the response to vitamin D supplementation.

We studied the association between CYP2R1 genetic polymorphisms and circulating 25-hydroxyvitamin D [25(OH)D] before and after supplementation with vitamin D3 in 218 elderly. We found differences between 3 and 8 ng/ml in circulating levels at baseline in women but not in the response after 1 year of supplementation. INTRODUCTION: This study evaluated the association between polymorphisms in four single nucleotide polymorphisms (SNPs) of the CYP2R1 gene and 25(OH)D levels before and 1 year after supplementation with two different doses of vitamin D3 (600 IU daily or a dose equivalent to 3750 IU daily), in a cohort of 218 (96 men and 122 women) Lebanese elderly overweight subjects. METHODS: Genotyping was performed for rs12794714, rs10741657, rs1562902, and rs10766197 SNPs using real-time PCR. The 25(OH)D levels were measured by liquid chromatography tandem mass spectrometry. RESULTS: At baseline, the mean ± SD age was 71.0 ± 4.7 years, BMI 30.3 ± 4.6 kg/m2, and 25(OH)D level was 20.5 ± 7.6 ng/ml. There were significant differences in mean 25(OH)D levels between genotypes in women, but not in men. After adjustment for age, season, and BMI, the homozygous for the low frequency gene variant (HLV) of rs1562902 and rs10741657 SNPs had the highest mean 25(OH)D levels with difference of 7.6 ng/ml for rs1562902 SNP (p < 0.01) and of 5.9 ng/ml for rs10741657 (p = 0.05) compared to the homozygous for the major polymorphisms (HMPs). Conversely, for rs10766197 and rs12794714 SNPs, HMP had the highest mean 25(OH)D levels with difference of 6 ng/ml for rs10766197 (p = 0.003) and of 4.8 ng/ml (p = 0.02) for rs12794714, compared to the HLV. CYP2R1 genetic polymorphisms explained 4.8 to 9.8 % of variability in 25(OH)D in women. After 1 year, there was no difference in the response to vitamin D3 supplementation between genotypes in either gender. CONCLUSION: This study showed a difference in 25(OH)D levels between CYP2R1 genotypes that equates a daily supplementation of 400-800 IU vitamin D, depending on genotype. It underscores possible important genetic contributions for the high prevalence of hypovitaminosis D in the Middle East.