Effects of Early Life Trauma on Risks for Adult Opioid Use Disorder Are Mediated by Stress and Occur Independent of Depression and Anxiety.

OBJECTIVES: Adverse childhood experiences, or early life trauma (ELT), may be a potential risk factor for opioid use disorders (OUDs) that could be further influenced by depression, anxiety, and stress. The prevalence and strength of these associations are largely unknown. METHODS: This study examined the association between current OUD severity and lifetime history of ELT, and the degree to which current depression, anxiety, and stress influenced this association, in persons (n = 310) with at least 1 lifetime exposure to opioids using an online survey. RESULTS: Ninety-three percent of respondents experienced at least 1 trauma in their lifetime, and 65% met the criteria for OUD. Early life trauma was largely unassociated with demographics but demonstrated an almost "dose-dependent" association among all forms of ELT (total, general, physical, emotional, sexual), whereby more ELT was associated with more severe current OUD. A multivariate mediation model found perceived stress to be a robust mediator of this association. Current psychiatric functioning did not significantly moderate the relationship between ELT and OUD, suggesting that ELT may impact OUD severity at varying levels of psychiatric functioning. CONCLUSIONS: These data support existing evidence that greater ELT may influence adult OUD severity and identify perceived stress as a potential mechanistic contributor to this association. Results are preliminary in nature but support continued research into mechanisms underlying the association between ELT and OUD, particularly conformational changes in the stress system resultant from ELT, and interventions to mitigate the impact of ELT on OUD development and/or develop trauma-informed OUD treatment approaches.

Far-red light allophycocyanin subunits play a role in chlorophyll d accumulation in far-red light.

Some terrestrial cyanobacteria acclimate to and utilize far-red light (FRL; λ = 700-800 nm) for oxygenic photosynthesis, a process known as far-red light photoacclimation (FaRLiP). A conserved, 20-gene FaRLiP cluster encodes core subunits of Photosystem I (PSI) and Photosystem II (PSII), five phycobiliprotein subunits of FRL-bicylindrical cores, and enzymes for synthesis of chlorophyll (Chl) f and possibly Chl d. Deletion mutants for each of the five apc genes of the FaRLiP cluster were constructed in Synechococcus sp. PCC 7335, and all had similar phenotypes. When the mutants were grown in white (WL) or red (RL) light, the cells closely resembled the wild-type (WT) strain grown under the same conditions. However, the WT and mutant strains were very different when grown under FRL. Mutants grown in FRL were unable to assemble FRL-bicylindrical cores, were essentially devoid of FRL-specific phycobiliproteins, but retained RL-type phycobilisomes and WL-PSII. The transcript levels for genes of the FaRLiP cluster in the mutants were similar to those in WT. Surprisingly, the Chl d contents of the mutant strains were greatly reduced (~ 60-99%) compared to WT and so were the levels of FRL-PSII. We infer that Chl d may be essential for the assembly of FRL-PSII, which does not accumulate to normal levels in the mutants. We further infer that the cysteine-rich subunits of FRL allophycocyanin may either directly participate in the synthesis of Chl d or that FRL bicylindrical cores stabilize FRL-PSII to prevent loss of Chl d.