1.
Transcriptome analyses unravel CYP1A1 and CYP1B1 as novel biomarkers for disinfection by-products (DBPs) derived from chlorinated algal organic matter.
Wu, B, Hong, H, Xia, Z, Liu, H, Chen, X, Chen, J, Yan, B, Liang, Y
Journal of hazardous materials. 2020;:121685
Abstract
Disinfection by-products (DBPs) are generated during chlorination of drinking water. Previous studies demonstrate that DBPs are cytotoxic, genotoxic and associated with an increased risk of human cancer. However, the molecular basis of DBPs-induced toxic effects remains unclear. Here, we chlorinated samples of algal-derived organic matter (AOM) and sediment organic matter (SOM) from a local drinking water reservoir. Chemical properties, toxicities and transcriptomic profiles of human Caco-2 cell exposed to AOM and SOM were compared before and after chlorination. We analyzed chlorination-caused distinct gene expression patterns between AOM and SOM, and identified a set of 22 differentially expressed genes under chlorination of AOM that are different from chlorinated SOM. Consequent network analysis indicates that differential CYP1A1, CYP1B1, ID1 and ID2 are common targets of the upstream regulators predicted in the AOM group, but not the SOM group. Through experimental validation and data integration from previous reports related to DBPs or environmental stressors, we found that CYP1A1 and CYP1B1 are specifically up-regulated after chlorinating AOM. Our study demonstrates that the two CYP1 genes likely act as novel biomarkers of AOM derived DBPs, and this would be helpful for testing drinking water DBPs toxicity and further monitoring drinking water safety.
2.
Antiretroviral therapy with the integrase inhibitor raltegravir alters decay kinetics of HIV, significantly reducing the second phase.
Murray, JM, Emery, S, Kelleher, AD, Law, M, Chen, J, Hazuda, DJ, Nguyen, BY, Teppler, H, Cooper, DA
AIDS (London, England). 2007;(17):2315-21
Abstract
OBJECTIVE Raltegravir (MK-0518) belongs to the new class of HIV integrase inhibitors. To date, there have been no reports investigating the potential for differential effects on viral dynamics with integrase inhibitors relative to current antiretroviral drugs. METHODS Patients in this phase II study (P004) were antiretroviral treatment naive. Part 1 of this study compared monotherapy with raltegravir (100 mg, 200 mg, 400 mg, or 600 mg twice daily) with placebo over 10 days. In part 2, patients were enrolled for 48 weeks of combination therapy, with randomization to one of the four dosages of raltegravir or to efavirenz, in addition to tenofovir and lamivudine. Mathematical models were used to investigate processes underlying viral dynamics. RESULTS From day 15 through to day 57, individuals in the raltegravir arm were significantly more likely to have HIV RNA < 50 copies/ml (P < or = 0.047). Plasma viral loads were 70% lower at initiation of second-phase decay for individuals taking raltegravir than for those taking efavirenz (P < 0.0001). This challenges the current hypothesis that second-phase virus originates from infected long-lived cells, as an integrase inhibitor should not impact on viral production from this cell population. Mathematical modeling supported two hypotheses as consistent with these observations: (i) that second-phase virus arises from cells newly infected by long-lived infected cells and (2) that it arises from activation of latently infected cells with full-length unintegrated HIV DNA. CONCLUSIONS These observations challenge the current understanding of HIV-1 turnover and compartmentalization. They also indicate the promise of this new integrase inhibitor raltegravir.