👤 Midori Ikezaki

Cerebral deposition of fibrillar amyloid-β (Aβ) is a pathological hallmark of Alzheimer's disease. Although Aβ is present in human placentas and accumulates in preeclamptic placentas characterized by poor placentation, the production and role of Aβ in the human placenta remain unclear. Because hypoxia in mid-to-late pregnancy is a risk for preeclampsia, we found that levels of hypoxia-inducible factor 1-α and β-secretase (BACE-1) increased concurrently with placental Aβ deposition in late-stage preeclamptic placentas. We also found that a human cytotrophoblast (CTB) model, BeWo cells, actually produced Aβ species and that hypoxia increased Aβ production and BACE-1 protein levels. Aβ42 fibrils inhibited CTB syncytialization, a critical step in maintaining pregnancy, by inducing loss of membrane localization of cell-cell adhesion molecules. Primary human CTBs confirmed these observations. Taken together, our results suggest that increased Aβ production in CTBs by hypoxia may lead to the formation of Aβ fibrils, which inhibit syncytiotrophoblast formation and are detrimental to pregnancy. Thus, our results reveal the novel role of Aβ fibrils in the pathogenesis of preeclampsia. Show less

Environmental and genetic factors are suggested to exhibit factor-based association with HDL-cholesterol (HDL-C) levels. However, the population-based effects of environmental and genetic factors have not been compared clearly. We conducted a cross-sectional study using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study to evaluate the population-based impact of smoking, drinking, and genetic factors on low HDL-C. Data from 11,498 men and women aged 35-69 years were collected for a genome-wide association study (GWAS). Sixty-five HDL-C-related SNPs with genome-wide significance (P < 5 × 10 We found that smoking, drinking, daily activity, habitual exercise, egg intake, BMI, age, sex, and the SNPs CETP rs3764261, APOA5 rs662799, LIPC rs1800588, LPL rs328, ABCA1 rs2575876, LIPG rs3786247, and APOE rs429358 were associated with HDL-C levels. The gene-environmental interactions on smoking and drinking were not statistically significant. The PAF for low HDL-C was the highest in men (63.2%) and in rs3764261 (31.5%) of the genetic factors, and the PAFs of smoking and drinking were 23.1% and 41.8%, respectively. The present study showed that the population-based impact of genomic factor CETP rs3764261 for low HDL-C was higher than that of smoking and lower than that of drinking. Show less