Reactive oxygen species and nitric oxide effect on the steroid hormone binding with serum albumin

Sublethal perfluorooctanoic acid and perfluorooctanesulfonic acid delay C. elegans larval development and population growth but do not alter egg hatching

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are polyfluoroalkyl substances (PFAS) used as surface coatings in manufacturing. Exposure to PFAS was shown to be correlated with infertility, low birth weight, and delayed aspects of pubertal development in mammals. Despite many correlational studies, there have been few direct investigations examining the link between PFAS exposure and early animal development. The aim of this study was to (1) examine the effects of PFOA on development and reproduction using the roundworm Caenorhabditis elegans, a model with a high predictive value for human reproductive toxicity and (2) compare observations to exposure to PFOS. PFAS exposure did not markedly alter egg hatching but delayed population growth, in part due to slower larval development. PFAS-exposed worms took longer to progress through larval stages to reach reproductive maturity, and this was not attributed to PFOA-induced toxicity to their food. Our results provide a robust benchmark for testing developmental and reproductive toxicity for other PFAS and PFAS-alternatives which continue to be used in manufacturing and released into the environment.

The Landscape of Interactions between Hypoxia-Inducible Factors and Reactive Oxygen Species in the Gastrointestinal Tract

The gastrointestinal tract (GT) is the major organ involved in digestion, absorption, and immunity, which is prone to oxidative destruction by high levels of reactive oxygen species (ROS) from luminal oxidants, such as food, drugs, and pathogens. Excessive ROS will lead to oxidative stresses and disrupt essential biomolecules, which also act as cellular signaling molecules in response to growth factors, hormones, and oxygen tension changes. Hypoxia-inducible factors (HIFs) are critical regulators mediating responses to cellular oxygen tension changes, which are also involved in energy metabolism, immunity, renewal, and microbial homeostasis in the GT. This review discusses interactions between HIF (mainly HIF-1α) and ROS and relevant diseases in the GT combined with our lab's work. It might help to develop new therapies for gastrointestinal diseases associated with ROS and HIF-1α.

Evaluation of albumin structural modifications through cobalt-albumin binding (CAB) assay

Human serum albumin (HSA) is the most abundant protein in the human body. HSA injections prepared by fractionating human blood have mainly covered the demand for albumin to treat hypoalbuminemia, the state of low concentration of albumin in blood. HSA in solution may exist in various forms such as monomers, oligomers, polymers, or as mixtures, and its conformational change and/or aggregation may occur easily. Considering these characteristics, there is a great chance of modification and polymer formation during the preparation processes of albumin products, especially injections. The albumin cobalt binding (ACB) test reported by Bar-Or et al. was originally designed to detect ischemia modified albumin (IMA), which contains the modified HSA N-terminal sequence by cleavage of the last two amino acids. In this study, we developed a cobalt albumin binding (CAB) assay to correct the flaws of the ACB test with improving the sensitivity and precision. The newly developed CAB assay easily detects albumin configuration alterations and may be able to be used in developing a quality control method for albumin and its pharmaceutical formulations including albumin injections.

Host APOL1 genotype is independently associated with proteinuria in HIV infection

Proteinuria is associated with adverse clinical outcomes in HIV infection. Here we evaluated whether APOL1 risk alleles, previously associated with advanced kidney disease, are independently associated with proteinuria in HIV infection in a cross-sectional study of HIV-infected women in the Women's Interagency HIV Study. We estimated the percent difference in urine protein excretion and odds of proteinuria (≥200 mg/g) associated with two versus one or no APOL1 risk allele using linear and logistic regression, respectively. Of 1285 women successfully genotyped, 379 carried one and 80 carried two risk alleles. Proteinuria was present in 124 women, 78 of whom had proteinuria confirmed on a second sample. In women without prior AIDS, two risk alleles were independently associated with a 69% higher urine protein excretion (95% confidence interval (CI): 36, 108) and five-fold higher odds of proteinuria (95% CI: 2.45, 10.37) as compared with one or no risk allele. No association was found in women with prior AIDS. Analyses in which women with impaired kidney function were excluded and proteinuria was confirmed by a second urine sample yielded similar estimates. Thus, APOL1 risk alleles are associated with significant proteinuria in HIV-infected persons without prior clinical AIDS, independent of clinical factors traditionally associated with proteinuria. Trials are needed to determine whether APOL1 genotyping identifies individuals who could benefit from earlier intervention to prevent overt renal disease.

Reactive oxygen species regulate FSH-induced expression of vascular endothelial growth factor via Nrf2 and HIF1α signaling in human epithelial ovarian cancer

Follicle-stimulating hormone (FSH) and the FSH receptor contribute to tumor angiogenesis and are acknowledged risk factors for ovarian epithelial cancer (OEC). Accumulating evidence suggests that FSH can induce vascular endothelial growth factor (VEGF) and hypoxia inducible factor 1α (HIF1α) expression. We previously demonstrated that FSH induces reactive oxygen species (ROS) production and activates Nrf2 signaling. This study was performed to investigate whether FSH induces VEGF expression via a ROS-mediated Nrf2 signaling pathway. In the current study, OET cells were treated with FSH; dichlorofluorescein staining was used to determine ROS generation, western blotting was used to quantify Nrf2 expression and VEGF expression was measured using an ELISA. Nrf2 and HIF1α were knocked down using siRNAs to investigate the role of the Nrf2 and HIF1α signaling pathways in FSH-induced VEGF expression. The chromatin immunoprecipitation assay (ChIP) was used to determine HIF1α binding to the VEGF promoter. Finally, it was found that FSH induced ROS production and activated Nrf2 signaling; elimination of ROS or knockdown of Nrf2 blocked FSH-induced VEGF expression. Knockdown of Nrf2 impaired HIF1α signaling activation. Blockage of the FSH-ROS-Nrf2-HIF1α signaling pathway attenuated FSH-induced binding of HIF1α to the VEGF promoter. Collectively, this study indicates that ROS and aberrant expression of Nrf2 play an important role in FSH-induced angiogenesis in OEC, and provides insight into the mechanisms of FSH-induced VEGF expression. Elimination of ROS or inhibition of Nrf2 may represent potential therapeutic targets for the treatment of ovarian cancer.