Gq/11-Mediated Signaling and Hypertrophy in Mice with Cardiac-Specific Transgenic Expression of Regulator of G-Protein Signaling 2

Cardiac hypertrophy is a well-established risk factor for cardiovascular morbidity and mortality. Activation of $G_{q/11}$-mediated signaling is required for pressure overload-induced cardiomyocyte (CM) hypertrophy to develop. We previously showed that among Regulators of G protein Signaling, RGS2 selectively inhibits $G_{q/11}$ signaling and its hypertrophic effects in isolated CM. In this study, we generated transgenic mice with CM-specific, conditional RGS2 expression (dTG) to investigate whether RGS2 overexpression can be used to attenuate $G_{q/11}$-mediated signaling and hypertrophy in vivo. Transverse aortic constriction (TAC) induced a comparable rise in ventricular mass and ANF expression and corresponding hemodynamic changes in dTG compared to wild types (WT), regardless of the TAC duration (1-8 wks) and timing of RGS2 expression (from birth or adulthood). Inhibition of endothelin-1-induced $G_{q/11}$-mediated phospholipase C β activity in ventricles and atrial appendages indicated functionality of transgenic RGS2. However, the inhibitory effect of transgenic RGS2 on $G_{q/11}$-mediated PLCβ activation differed between ventricles and atria: (i) in sham-operated dTG mice the magnitude of the inhibitory effect was less pronounced in ventricles than in atria, and (ii) after TAC, negative regulation of $G_{q/11}$ signaling was absent in ventricles but fully preserved in atria. Neither difference could be explained by differences in expression levels, including marked RGS2 downregulation after TAC in left ventricle and atrium. Counter-regulatory changes in other $G_{q/11}$-regulating RGS proteins (RGS4, RGS5, RGS6) and random insertion were also excluded as potential causes. Taken together, despite ample evidence for a role of RGS2 in negatively regulating $G_{q/11}$ signaling and hypertrophy in CM, CM-specific RGS2 overexpression in transgenic mice in vivo did not lead to attenuate ventricular $G_{q/11}$-mediated signaling and hypertrophy in response to pressure overload. Furthermore, our study suggests chamber-specific differences in the regulation of RGS2 functionality and potential future utility of the new transgenic model in mitigating $G_{q/11}$ signaling in the atria in vivo

Endoscopic submucosal dissection for early esophageal adenocarcinoma: low rates of metastases in mucosal cancers with poor differentiation

Background and aims Endoscopic resection (ER) is accepted as standard treatment for intramucosal esophageal adenocarcinoma (EAC) with well or moderate differentiation. Poor differentiation (PD) is judged as a risk factor for lymph node metastasis (LNM) and surgery is recommended. However, the evidence for this recommendation is weak. Study aim was to analyze the clinical course of patients after ER of EAC with PD. Patients and methods Patients undergoing endoscopic submucosal dissection for EAC were included from 16 German centers. Inclusion criteria were PD in the resection specimen, R0 resection and endoscopic follow-up. Primary outcome was the metastasis rate during follow-up. Analysis was performed retrospectively in a prospectively collected database. Results 25 patients with PD as single risk factor (group A) and 15 patients with PD and additional risk factors (submucosal invasion and/or lymphovascular invasion) were included. The metastasis rate was was 1/25 (4.0%; 95%CI 0.4-17.2) in group A and 3/15 (20.0%; 95%CI 6.0-44.4%) in group B, respectively (p=0.293). The rate of EAC-associated deaths was 1/25 (4%; 95%CI 0.4-17.2%) versus 3/15 (20%; 95%CI 6.0-44.4%) in group B (p=0.293) while the overall death rate was 7/25 (28.0%; 95%CI 13.5-47.3%) versus 3/15 (20%; 95%CI 6.0-44.4%) (p=0.715). Median follow-up was 30 months (IQR 15-53). Conclusions During long-term follow-up the risk of metastasis is low after ER of mucosal EAC with PD as single risk factor. A conservative approach seems justified in this small patient group. However, the treatment strategy has to be determined on an individualized basis until further prospective data are available

The genomic and transcriptional landscape of primary central nervous system lymphoma

Primary lymphomas of the central nervous system (PCNSL) are mainly diffuse large B-cell lymphomas (DLBCLs) confined to the central nervous system (CNS). Molecular drivers of PCNSL have not been fully elucidated. Here, we profile and compare the whole-genome and transcriptome landscape of 51 CNS lymphomas (CNSL) to 39 follicular lymphoma and 36 DLBCL cases outside the CNS. We find recurrent mutations in JAK-STAT, NFkB, and B-cell receptor signaling pathways, including hallmark mutations in MYD88 L265P (67%) and CD79B (63%), and CDKN2A deletions (83%). PCNSLs exhibit significantly more focal deletions of HLA-D (6p21) locus as a potential mechanism of immune evasion. Mutational signatures correlating with DNA replication and mitosis are significantly enriched in PCNSL. TERT gene expression is significantly higher in PCNSL compared to activated B-cell (ABC)-DLBCL. Transcriptome analysis clearly distinguishes PCNSL and systemic DLBCL into distinct molecular subtypes. Epstein-Barr virus (EBV)+ CNSL cases lack recurrent mutational hotspots apart from IG and HLA-DRB loci. We show that PCNSL can be clearly distinguished from DLBCL, having distinct expression profiles, IG expression and translocation patterns, as well as specific combinations of genetic alterations

127 Advance RI-K Scholar Career Development Program: A one-year intensive program for developing early career faculty in an IDeA state

OBJECTIVES/GOALS: We developed a state-wide program to support early career faculty in preparing mentored career development awards, and connect them to resources, mentorship, and career development opportunities. We aimed to build self-efficacy along multiple axes, including research design and grantsmanship, and to facilitate networking with mentors and peers. METHODS/STUDY POPULATION: The program recruited four cohorts of faculty over the course of four years, for a total of 32 faculty participants (63% physician scientists). Participants were selected by a Steering Committee, and represented a variety of specialties from 19 departments across Brown University, University of Rhode Island, and affiliated hospitals. Participation required an institutional commitment of 20% minimum protected time to engage in research and a year-long curriculum that included biweekly didactic sessions, project development support, individual consultations, feedback on drafts, and internal study section review. Participants completed pre-, interim-, and final-assessments, which collected measures of self-efficacy, professional development needs, program satisfaction, and formative feedback. RESULTS/ANTICIPATED RESULTS: Over the first 3 years, 21 participants completed the program, 43% have received NIH or VA K/CDA awards so far, and 48% received other federal or non-federal awards. Over 25 faculty from across institutions participated in leadership and didactics, with even greater participation on mentorship teams, panels, and grant review. All cohorts showed improvements in measures of self-efficacy in grantsmanship and research and reported high satisfaction with program activities. Participants found individualized proposal feedback and internal study sections to be most valuable, and frequently cited the value of peer-learning opportunities. Challenges for scholars include mentorship challenges, competing priorities/protected time, and various external factors that impacted individual research progress. DISCUSSION/SIGNIFICANCE: The program has successfully supported cohorts of junior clinical and translational faculty from across the state in launching their independent research careers. The program may serve as a model for IDeA state inter-institutional collaboration in developing diverse faculty cohorts in the early stages of preparing their career development award