ABSTRACT
Recent genome-wide association studies have established that most complex disease-associated loci are found in noncoding regions where defining their function is nontrivial. In this study, we leverage a modular massively parallel reporter assay (MPRA) to uncover sequence features linked to context-specific regulatory activity. We screened enhancer activity across a panel of 198-bp fragments spanning over 10k type 2 diabetes- and metabolic trait-associated variants in the 832/13 rat insulinoma cell line, a relevant model of pancreatic beta cells. We explored these fragments' context sensitivity by comparing their activities when placed up-or downstream of a reporter gene, and in combination with either a synthetic housekeeping promoter (SCP1) or a more biologically relevant promoter corresponding to the human insulin gene ( INS ). We identified clear effects of MPRA construct design on measured fragment enhancer activity. Specifically, a subset of fragments (n = 702/11,656) displayed positional bias, evenly distributed across up- and downstream preference. A separate set of fragments exhibited promoter bias (n = 698/11,656), mostly towards the cell-specific INS promoter (73.4%). To identify sequence features associated with promoter preference, we used Lasso regression with 562 genomic annotations and discovered that fragments with INS promoter-biased activity are enriched for HNF1 motifs. HNF1 family transcription factors are key regulators of glucose metabolism disrupted in maturity onset diabetes of the young (MODY), suggesting genetic convergence between rare coding variants that cause MODY and common T2D-associated regulatory variants. We designed a follow-up MPRA containing HNF1 motif-enriched fragments and observed several instances where deletion or mutation of HNF1 motifs disrupted the INS promoter-biased enhancer activity, specifically in the beta cell model but not in a skeletal muscle cell line, another diabetes-relevant cell type. Together, our study suggests that cell-specific regulatory activity is partially influenced by enhancer-promoter compatibility and indicates that careful attention should be paid when designing MPRA libraries to capture context-specific regulatory processes at disease-associated genetic signals.
ABSTRACT
BACKGROUND: Individual disposition of goal orientation and situational factors of the working context, both generate and modulate motives to seek feedback. AIM: We looked for correlations between feedback-seeking and individual goal orientation, motives or concerns of feedback-seeking, working context of medical residents. We focussed on how promotion of feedback-seeking by supervisors and educational environment influenced motives and behaviours of feedback-seeking in residents. METHODS: Web-based administration of a Likert-type composite questionnaire to residents of a tertiary care teaching hospital in Switzerland and mini-interviews. RESULTS: Fifty-six (45%) of 125 residents completed the questionnaire. After multiple regression analysis promotion of feedback-seeking through supervisors remained the sole predictor correlating with feedback-seeking through inquiry (R(2) = 16) and the motive of self-improvement (R(2) = 0.30). This predictor was also associated with reduced concerns of ego-protection (R(2) = 0.14) and impression-defence (R(2) = 0.18). Performance-avoid goal orientation was associated with concerns of impression-defence (R(2) = 0.36) and ego-protection (R(2) = 0.48). Women had significantly more concerns of ego-protection, residents with more than three years of experience more concerns of impression-defence. Disillusion that PG-training would ever improve, seemed the main reason to refuse participation CONCLUSIONS: Promotion of feedback-seeking through supervisors combined with delivery of high quality feedback may guide residents towards seeking feedback for professional self-improvement.
