479 Effects of extracellular matrix on pacemaking cardiomyocyte function

Objectives/Goals: The extracellular matrix (ECM) of the sinoatrial node (SAN) is critical for maintaining automaticity in hiPSC-derived pacemaking cardiomyocytes (PCMs) under cyclic strain. We aim to determine the ECM ligands responsible for cell-ECM mediated mechanotransduction and the resulting ph...

Full description

Saved in:
Bibliographic Details
Main Authors: Brian Howard, Regan Smithers, Kaitlin Van Brusselen, Hillary K.J. Kao, Deborah K. Lieu
Format: Article
Language:English
Published: Cambridge University Press 2025-04-01
Series:Journal of Clinical and Translational Science
Online Access:https://www.cambridge.org/core/product/identifier/S2059866124010707/type/journal_article
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849393744058515456
author Brian Howard
Regan Smithers
Kaitlin Van Brusselen
Hillary K.J. Kao
Deborah K. Lieu
author_facet Brian Howard
Regan Smithers
Kaitlin Van Brusselen
Hillary K.J. Kao
Deborah K. Lieu
author_sort Brian Howard
collection DOAJ
description Objectives/Goals: The extracellular matrix (ECM) of the sinoatrial node (SAN) is critical for maintaining automaticity in hiPSC-derived pacemaking cardiomyocytes (PCMs) under cyclic strain. We aim to determine the ECM ligands responsible for cell-ECM mediated mechanotransduction and the resulting phenotype in PCMs. Methods/Study Population: HiPSCs are differentiated to PCM and replated on substrate with 5 or 15 kPa PDMS that are coated with 5 or 25 ug/cm of either collagen I or fibronectin at sub-confluent density to restrict junction engagement to only costameres. Then, PCM are subjected to 10% cyclic mechanical strain at 1 Hz for 48 hours, with static culture as control. PCMs from all conditions are subsequently fixed and stained for cardiomyocyte-specific troponin T (TnT), pacemaking HCN4 channel, and pro-pacemaking transcription factors (Shox2, Isl1, Tbx3, Tbx18). Additionally, PCM cell size will also be assessed. Results/Anticipated Results: Considering the amount of hypertrophy and myofilament in CMs correlates with mechanical strain, we expect a reduced degree of mechanotransduction in hiPSC-PCM on collagen I with a stiffness 15 kPa to induce smaller cell size with fewer myofilament and an upregulation of HCN4 and pro-pacemaking transcription factors than those on 5 kPa and those on fibronectin of either 5 or 15 kPa after cyclic strain. This is because COL1 is reported to have a lower signaling threshold but a limited sensitivity to force which contributes to the diminished mechanotransduction signaling. Discussion/Significance of Impact: Effects of the microenvironment on hiPSC-PCMs via costamere mechanotransduction may provide insights for engineering biopacemakers with a suitable ECM, to potentially preserve automaticity in hiPSC-PCMs and sustain long-term pacemaking function, making biopacemakers a step closer to reality.
format Article
id doaj-art-43e2727a2eee40e78dd75fd48aaa3038
institution Kabale University
issn 2059-8661
language English
publishDate 2025-04-01
publisher Cambridge University Press
record_format Article
series Journal of Clinical and Translational Science
spelling doaj-art-43e2727a2eee40e78dd75fd48aaa30382025-08-20T03:40:18ZengCambridge University PressJournal of Clinical and Translational Science2059-86612025-04-01914114210.1017/cts.2024.1070479 Effects of extracellular matrix on pacemaking cardiomyocyte functionBrian Howard0Regan Smithers1Kaitlin Van Brusselen2Hillary K.J. Kao3Deborah K. Lieu4University of California, Davis Department of Internal Medicine, Division of Cardiovascular Medicine and Institute for Regenerative CuresUniversity of California, Davis Department of Internal Medicine, Division of Cardiovascular Medicine and Institute for Regenerative CuresUniversity of California, Davis Department of Internal Medicine, Division of Cardiovascular Medicine and Institute for Regenerative CuresUniversity of California, Davis Department of Internal Medicine, Division of Cardiovascular Medicine and Institute for Regenerative CuresUniversity of California, Davis Department of Internal Medicine, Division of Cardiovascular Medicine and Institute for Regenerative CuresObjectives/Goals: The extracellular matrix (ECM) of the sinoatrial node (SAN) is critical for maintaining automaticity in hiPSC-derived pacemaking cardiomyocytes (PCMs) under cyclic strain. We aim to determine the ECM ligands responsible for cell-ECM mediated mechanotransduction and the resulting phenotype in PCMs. Methods/Study Population: HiPSCs are differentiated to PCM and replated on substrate with 5 or 15 kPa PDMS that are coated with 5 or 25 ug/cm of either collagen I or fibronectin at sub-confluent density to restrict junction engagement to only costameres. Then, PCM are subjected to 10% cyclic mechanical strain at 1 Hz for 48 hours, with static culture as control. PCMs from all conditions are subsequently fixed and stained for cardiomyocyte-specific troponin T (TnT), pacemaking HCN4 channel, and pro-pacemaking transcription factors (Shox2, Isl1, Tbx3, Tbx18). Additionally, PCM cell size will also be assessed. Results/Anticipated Results: Considering the amount of hypertrophy and myofilament in CMs correlates with mechanical strain, we expect a reduced degree of mechanotransduction in hiPSC-PCM on collagen I with a stiffness 15 kPa to induce smaller cell size with fewer myofilament and an upregulation of HCN4 and pro-pacemaking transcription factors than those on 5 kPa and those on fibronectin of either 5 or 15 kPa after cyclic strain. This is because COL1 is reported to have a lower signaling threshold but a limited sensitivity to force which contributes to the diminished mechanotransduction signaling. Discussion/Significance of Impact: Effects of the microenvironment on hiPSC-PCMs via costamere mechanotransduction may provide insights for engineering biopacemakers with a suitable ECM, to potentially preserve automaticity in hiPSC-PCMs and sustain long-term pacemaking function, making biopacemakers a step closer to reality.https://www.cambridge.org/core/product/identifier/S2059866124010707/type/journal_article
spellingShingle Brian Howard
Regan Smithers
Kaitlin Van Brusselen
Hillary K.J. Kao
Deborah K. Lieu
479 Effects of extracellular matrix on pacemaking cardiomyocyte function
Journal of Clinical and Translational Science
title 479 Effects of extracellular matrix on pacemaking cardiomyocyte function
title_full 479 Effects of extracellular matrix on pacemaking cardiomyocyte function
title_fullStr 479 Effects of extracellular matrix on pacemaking cardiomyocyte function
title_full_unstemmed 479 Effects of extracellular matrix on pacemaking cardiomyocyte function
title_short 479 Effects of extracellular matrix on pacemaking cardiomyocyte function
title_sort 479 effects of extracellular matrix on pacemaking cardiomyocyte function
url https://www.cambridge.org/core/product/identifier/S2059866124010707/type/journal_article
work_keys_str_mv AT brianhoward 479effectsofextracellularmatrixonpacemakingcardiomyocytefunction
AT regansmithers 479effectsofextracellularmatrixonpacemakingcardiomyocytefunction
AT kaitlinvanbrusselen 479effectsofextracellularmatrixonpacemakingcardiomyocytefunction
AT hillarykjkao 479effectsofextracellularmatrixonpacemakingcardiomyocytefunction
AT deborahklieu 479effectsofextracellularmatrixonpacemakingcardiomyocytefunction