Reprogramming cell fate with a genome-scale library of artificial transcription factors.

Artificial transcription factors (ATFs) are precision-tailored molecules designed to bind DNA and regulate transcription in a preprogrammed manner. Libraries of ATFs enable the high-throughput screening of gene networks that trigger cell fate decisions or phenotypic changes. We developed a genome-scale library of ATFs that display an engineered interaction domain (ID) to enable cooperative assembly and synergistic gene expression at targeted sites. We used this ATF library to screen for key regulators of the pluripotency network and discovered three combinations of ATFs capable of inducing pluripotency without exogenous expression of Oct4 (POU domain, class 5, TF 1). Cognate site identification, global transcriptional profiling, and identification of ATF binding sites reveal that the ATFs do not directly target Oct4; instead, they target distinct nodes that converge to stimulate the endogenous pluripotency network. This forward genetic approach enables cell type conversions without a priori knowledge of potential key regulators and reveals unanticipated gene network dynamics that drive cell fate choices.

Experiences of LGBTQ+ Residents in US General Surgery Training Programs.

Importance: Previous studies have shown high rates of mistreatment among US general surgery residents, leading to poor well-being. Lesbian, gay, bisexual, transgender, queer, and other sexual and gender minority (LGBTQ+) residents represent a high-risk group for mistreatment; however, their experience in general surgery programs is largely unexplored. Objective: To determine the national prevalence of mistreatment and poor well-being for LGBTQ+ surgery residents compared with their non-LGBTQ+ peers. Design, Setting, and Participants: A voluntary, anonymous survey adapting validated survey instruments was administered to all clinically active general surgery residents training in Accreditation Council for Graduate Medical Education-accredited general surgery programs following the 2019 American Board of Surgery In-Training Examination. Main Outcomes and Measures: Self-reported mistreatment, sources of mistreatment, perceptions of learning environment, career satisfaction, burnout, thoughts of attrition, and suicidality. The associations between LGBTQ+ status and (1) mistreatment, (2) burnout, (3) thoughts of attrition, and (4) suicidality were examined using multivariable regression models, accounting for interactions between gender and LGBTQ+ identity. Results: A total of 6956 clinically active residents completed the survey (85.6% response rate). Of 6381 respondents included in this analysis, 305 respondents (4.8%) identified as LGBTQ+ and 6076 (95.2%) as non-LGBTQ+. Discrimination was reported among 161 LGBTQ+ respondents (59.2%) vs 2187 non-LGBTQ+ respondents (42.3%; P < .001); sexual harassment, 131 (47.5%) vs 1551 (29.3%; P < .001); and bullying, 220 (74.8%) vs 3730 (66.9%; P = .005); attending surgeons were the most common overall source. Compared with non-LGBTQ+ men, LGBTQ+ residents were more likely to report discrimination (men: odds ratio [OR], 2.57; 95% CI, 1.78-3.72; women: OR, 25.30; 95% CI, 16.51-38.79), sexual harassment (men: OR, 2.04; 95% CI, 1.39-2.99; women: OR, 5.72; 95% CI, 4.09-8.01), and bullying (men: OR, 1.51; 95% CI, 1.07-2.12; women: OR, 2.00; 95% CI, 1.37-2.91). LGBTQ+ residents reported similar perceptions of the learning environment, career satisfaction, and burnout (OR, 1.22; 95% CI, 0.97-1.52) but had more frequent considerations of leaving their program (OR, 2.04; 95% CI, 1.52-2.74) and suicide (OR, 1.95; 95% CI, 1.26-3.04). This increased risk of suicidality was eliminated after adjusting for mistreatment (OR, 1.47; 95% CI, 0.90-2.39). Conclusions and Relevance: Mistreatment is a common experience for LGBTQ+ surgery residents, with attending surgeons being the most common overall source. Increased suicidality among LGBTQ+ surgery residents is associated with this mistreatment. Multifaceted interventions are necessary to develop safer and more inclusive learning environments.

Reprogramming cell fate with artificial transcription factors.

Transcription factors (TFs) reprogram cell states by exerting control over gene regulatory networks and the epigenetic landscape of a cell. Artificial transcription factors (ATFs) are designer regulatory proteins comprised of modular units that can be customized to overcome challenges faced by natural TFs in establishing and maintaining desired cell states. Decades of research on DNA-binding proteins and synthetic molecules has provided a molecular toolkit for ATF design and the construction of genome-scale libraries of ATFs capable of phenotypic manipulation and reprogramming of cell states. Here, we compare the unique strengths and limitations of different ATF platforms, highlight the advantages of cooperative assembly, and present the potential of ATF libraries in revealing gene regulatory networks that govern cell fate choices.