I. ABSTRACT Heart disease remains the leading cause of death in the United States. Despite what we know about the risk factors associated with heart disease, the molecular mechanisms are still largely unknown. The healthy adult heart is unique from other tissues in that the rate of protein synthesis is dramatically lower than in most tissues and lower than the developing heart. However, during cardiac hypertrophy, translation rates increase. This suggests a tissue-specific mechanism for regulating translation rates in the mammalian heart. Our lab has identified a mechanism by which total protein synthesis in cardiomyocytes is decreased during development through shortening of poly(A) tails, leading to a decrease in polysome formation through the closed-loop model of translation. This regulation is reversed during both physiologic and pathologic hypertrophy when the translation needs of cardiomyocytes are increased. Also, we have discovered that the nuclear poly(A) binding protein (PABPN1) is post-transcriptionally silenced in mammalian adult cardiac and skeletal muscle but it becomes re-expressed in pathologic cardiac hypertrophy. PABPN1 is a regulator of alternative polyadenylation (APA) and poly(A) tail length, both of which can influence the translation of transcripts. Our central hypothesis is that PABPN1 is dynamically regulated in cardiac myocytes to tune translation rates and suite growth needs through a polyadenylation dependent mechanism. The objective of this proposal is to elucidate the exact function(s) of PABPN1 in cardiac development and growth and identify how PABPN1 is regulated during these conditions.
Aims 1 and 2 will use conditional PABPN1-knockout and overexpressing mice to determine the physiologic roles of PABPN1 in cardiac development and hypertrophy while defining the molecular basis of PABPN1 activity and its role in determining cardiac-specific gene expression programs.
In Aim 3, we will use super-resolution microscopy, CRISPR-Cas9 mediated genome editing, and RNA antisense-oligo pulldown approaches to identify the regulatory mechanism(s) and factors that post-transcriptionally silence PABPN1 during cardiac development.

Public Health Relevance

The proposed studies will provide a deep understanding of the genetic programs that regulate normal cardiac growth during development; and reactivate fetal gene expression in adult heart under disease conditions. This project will also dissect the functional role of a nuclear poly (A) binding protein in stimulation of cardiac hypertrophy, a condition that often accompanies the response to myocardial infarction and heart failure. Completion of the proposed aims will provide unprecedented insight into how the cardiac transcriptome is shaped into the cardiac translatome and potentially uncover new regulatory pathways to target with therapeutics.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL126845-06
Application #
10051934
Study Section
Cardiovascular Differentiation and Development Study Section (CDD)
Program Officer
Schwartz, Lisa
Project Start
2015-04-01
Project End
2024-06-30
Budget Start
2020-08-01
Budget End
2021-06-30
Support Year
6
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Illinois Urbana-Champaign
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820
Bangru, Sushant; Arif, Waqar; Seimetz, Joseph et al. (2018) Alternative splicing rewires Hippo signaling pathway in hepatocytes to promote liver regeneration. Nat Struct Mol Biol 25:928-939
Misra, Chaitali; Lin, Feikai; Kalsotra, Auinash (2018) Deregulation of RNA Metabolism in Microsatellite Expansion Diseases. Adv Neurobiol 20:213-238
Seimetz, Joseph; Arif, Waqar; Bangru, Sushant et al. (2018) Cell-type specific polysome profiling from mammalian tissues. Methods :
Aguero, Tristan; Jin, Zhigang; Chorghade, Sandip et al. (2017) Maternal Dead-end 1 promotes translation of nanos1 by binding the eIF3 complex. Development 144:3755-3765
Lewis, Cole J T; Pan, Tao; Kalsotra, Auinash (2017) RNA modifications and structures cooperate to guide RNA-protein interactions. Nat Rev Mol Cell Biol 18:202-210
Liu, Dai-Chi; Seimetz, Joseph; Lee, Kwan Young et al. (2017) Mdm2 mediates FMRP- and Gp1 mGluR-dependent protein translation and neural network activity. Hum Mol Genet 26:3895-3908
Yum, Kevin; Wang, Eric T; Kalsotra, Auinash (2017) Myotonic dystrophy: disease repeat range, penetrance, age of onset, and relationship between repeat size and phenotypes. Curr Opin Genet Dev 44:30-37
Chorghade, Sandip; Seimetz, Joseph; Emmons, Russell et al. (2017) Poly(A) tail length regulates PABPC1 expression to tune translation in the heart. Elife 6:
Arif, Waqar; Datar, Gandhar; Kalsotra, Auinash (2017) Intersections of post-transcriptional gene regulatory mechanisms with intermediary metabolism. Biochim Biophys Acta Gene Regul Mech 1860:349-362
Skariah, Geena; Seimetz, Joseph; Norsworthy, Miles et al. (2017) Mov10 suppresses retroelements and regulates neuronal development and function in the developing brain. BMC Biol 15:54

Showing the most recent 10 out of 14 publications