Estrogenic Regulation of Lysyl Oxidase in Cardiac Fibroblasts
Publication Date
July 2019
Location
LSU Health Medical Education Building
Document Type
Abstract
Start Date
26-7-2019 9:00 AM
End Date
26-7-2019 12:00 PM
Description
According to the American Heart Association’s 2019 update, heart disease remains the number one cause of death in the United States, accounting for approximately 363,452 deaths in 2016 and costing 218.7 billion dollars annually. Although cardiac disease is the leading cause of death in both men and women, women develop heart disease ten years later than men. Yet, after menopause, the incidence of heart disease in women is similar to men, suggesting that estrogen may play a part in premenopausal cardioprotection. Previously, the Gardner lab found that ovariectomized rats lost the cardioprotective effects demonstrated by intact females. Further, adverse cardiac remodeling was associated with high lysyl oxidase (LOX) expression and activity in male rats, with mortality rates of 24.5% in male rates to 2.5% in females after 8 weeks of volume overload stress. It is not known if estrogen regulates cardiac LOX and if this regulation plays a role in premenopausal cardioprotection. We hypothesize that estrogen regulates LOX activity and expression through the TGFβ pathway. To assess how estrogen regulates LOX, cardiac fibroblasts were isolated from 10- week-old, adult, female rats and treated with estrogen (10μM), TGFβ (10μM), estrogen + TGFβ (10μM), estrogen +TGFβ antagonist (SB-505124, 10μM), DPN (estrogen receptor β agonist, 10 μM), PPT (estrogen receptor α agonist, 10 μM) and vehicle (DMSO). After the cells were plated, and expanded, they were exposed to the above treatments for up to 24 hours. LOX activity in conditioned media was assessed via commercially available fluorescent assay (AAT Bioquest, Sunnyvale, CA). LOX expression was assessed using qRT-PCR of fibroblast mRNA. Findings in LOX activity assay showed an arbitrary fluoresce per minute of 17210 ± 587.9 in DMSO, 23703 ± 1044 in estrogen, 18460 ± 769.5 in DPN (β agonist), and 22238 ± 1068 In PPT (α agonist). Estrogen significantly increased LOX activity (38% versus vehicle DMSO; p<0.05). The effects of TGFβ and additional measures of LOX mRNA via qPCR are underway.
Recommended Citation
Foley, Tierra A., "Estrogenic Regulation of Lysyl Oxidase in Cardiac Fibroblasts" (2019). Summer Research Internship Program. 12.
https://digitalscholar.lsuhsc.edu/srip/2019/undergrad/12
Estrogenic Regulation of Lysyl Oxidase in Cardiac Fibroblasts
LSU Health Medical Education Building
According to the American Heart Association’s 2019 update, heart disease remains the number one cause of death in the United States, accounting for approximately 363,452 deaths in 2016 and costing 218.7 billion dollars annually. Although cardiac disease is the leading cause of death in both men and women, women develop heart disease ten years later than men. Yet, after menopause, the incidence of heart disease in women is similar to men, suggesting that estrogen may play a part in premenopausal cardioprotection. Previously, the Gardner lab found that ovariectomized rats lost the cardioprotective effects demonstrated by intact females. Further, adverse cardiac remodeling was associated with high lysyl oxidase (LOX) expression and activity in male rats, with mortality rates of 24.5% in male rates to 2.5% in females after 8 weeks of volume overload stress. It is not known if estrogen regulates cardiac LOX and if this regulation plays a role in premenopausal cardioprotection. We hypothesize that estrogen regulates LOX activity and expression through the TGFβ pathway. To assess how estrogen regulates LOX, cardiac fibroblasts were isolated from 10- week-old, adult, female rats and treated with estrogen (10μM), TGFβ (10μM), estrogen + TGFβ (10μM), estrogen +TGFβ antagonist (SB-505124, 10μM), DPN (estrogen receptor β agonist, 10 μM), PPT (estrogen receptor α agonist, 10 μM) and vehicle (DMSO). After the cells were plated, and expanded, they were exposed to the above treatments for up to 24 hours. LOX activity in conditioned media was assessed via commercially available fluorescent assay (AAT Bioquest, Sunnyvale, CA). LOX expression was assessed using qRT-PCR of fibroblast mRNA. Findings in LOX activity assay showed an arbitrary fluoresce per minute of 17210 ± 587.9 in DMSO, 23703 ± 1044 in estrogen, 18460 ± 769.5 in DPN (β agonist), and 22238 ± 1068 In PPT (α agonist). Estrogen significantly increased LOX activity (38% versus vehicle DMSO; p<0.05). The effects of TGFβ and additional measures of LOX mRNA via qPCR are underway.
Comments
Mentor: Dr. Jason Gardner, Department of Physiology