Teens and young adults are increasingly using electronic cigarettes, but little is known about the long-term cardiopulmonary health effects of these nicotine-delivery devices. During this webinar, Jason Gardner, PhD, presents his latest findings using a mouse model of chronic, inhaled nicotine exposure. Post-exposure to nicotine caused mice to develop pulmonary hypertension (PH) and right ventricular (RV) remodeling, a phenomenon that is prevented using an angiotensin II type I receptor (AT1) blocker, losartan. Dr. Gardner discusses the details of this work and how the renin-angiotensin system plays a key role in PH and RV remodeling. In addition, he expands upon the current research with new, unpublished findings. For more information or to watch the webinar, visit https://bit.ly/3guetlr

1. Copyright 2022. All Rights Reserved. Contact Presenter for Permission
Cardiac Effects of Chronically
Inhaled Nicotine
Jason Gardner, PhD
Physiology
LSU Health Sciences Center – New Orleans
Professor

2. Jason D. Gardner, Ph.D.
Department of Physiology
Louisiana State University
Health Sciences Center
New Orleans
Cardiac Effects of
Chronically Inhaled Nicotine

3. Cigarette Smoking and Vaping Trends
• Cigarette smoking is an independent risk factor
for cardiovascular disease, including
hypertension, stroke, and atherosclerosis.
• Cigarette usage is on the decline, yet ~480K
deaths/year (CDC).
• Electronic Nicotine Delivery Systems (ENDS),
such as JUUL and e-Cigs, are thought to be a
safer alternative.
• ENDS use by youth & young adults is on the
rise. Age 19-22 ~22% vaped in past 30 days (CDC;
Cullen et al., MMWR, 2018; Dai & Leventhal, JAMA, 2019).

4. Next Generation Tobacco Products – Heat-not-Burn
Philip Morris IQOS HNB Device
• Promoted as a “smoking cessation” aid or “safe”
alternative to cigarettes.
• HNB devices heat tobacco to sub-combustion
temperatures, theoretically reducing toxicity. CV
effects are poorly characterized (Fried & Gardner,
AJP-Heart and Circ, 2020).
• 45% of Italian users are never smokers; 96% of
Korean users also smoke cigarettes (Liu et al., Tob
Control, 2019; Kim et al., Tob Control, 2018).
• 1.6% of US students are using HNB devices (Dai,
Drug Alcohol Depend, 2019).

5. Nicotine and Cardiovascular Disease
“A greater understanding of the impacts of nicotine on cardiovascular
health, and nicotine delivery products on children and youth, is necessary
to inform further treatment and regulatory approaches to nicotine”
JACC 2021

6. Nicotine and Cardiovascular System
• Acute inhalation and transdermal nicotine both lead to transient
increases in systolic and diastolic BP and HR (Cooke et al., 2015;
Tanus-Santos et al., 2001).
• Studies of chronic nicotine exposure primarily use injection or
minipump delivery.
• Few studies utilize chronic nicotine inhalation models.
Does chronic inhalation of nicotine cause hypertension,
cardiac dysfunction and remodeling?

7. La Jolla Alcohol Research, Inc.
• C57BL/6J mice; 8 wks age; male
• Nicotine free base (Sigma)
• Air bubbled through nicotine.
• Nicotine-air mixture is delivered to chamber.
• Daily 12h on/12h off
Chronic Nicotine Inhalation Delivery System
• Serum cotinine as an
indicator of exposure
Air Control Nicotine
0
200
400
600
800
1000 ***
Serum
Cotinine
(ng/ml)
***p<0.001

8. ± Nicotine exposure
Systemic BP and HR recording
-1 0 2 4 6 8 weeks
Sacrifice
❶ BP telemetry probe implantation (DSI)
❷ Ultrasound echocardiogram (LV and RV); Visualsonics VEVO 3100
❸ Millar catheter (SPR 1000) via jugular: Right ventricular systolic pressure (RVSP)
❶ ❷
❷ ❸
Experimental Design

9. Effects of Chronic Nicotine Inhalation on Systemic BP
Nicotine caused a significant increase in systemic BP by 1 wk that resolved by 4 wks.
Systolic BP for air, nicotine, and AngII-infused mice (Air, n=18; Nicotine, n=18; AngII (450 ng/kg/min, n=12).
WEEK
1
WEEK
2
WEEK
3
WEEK
4

10. Effects of Chronic Nicotine Inhalation on Left Heart
LV echocardiography of air- and nicotine-exposed mice (Air, n=22; Nicotine, n=23).

11. RV Ultrasound of air- and nicotine-exposed mice. Air, n=8; Nicotine, n=9. *p<0.05.
Effects of Chronic Nicotine Inhalation on Right Heart

12. Effects of Chronic Nicotine Inhalation on Right Heart
Air Nicotine
0
10
20
30
Fulton
Index
[RV/(LV+S)*100%]
*
Air Nicotine
0.0
0.5
1.0
1.5
2.0
2.5
PVR
(mmHgminmL
-1
)
*
*p<0.05
**p<0.01
PVR = (RVSP-LVEDP)/CO
Millar SPR-1000 pressure catheter

13. Chronic Nicotine Inhalation Activates Renin-Angiotensin System (RAS)
*p<0.05
**p<0.01
Air
Nicotine
RV LV

14. Chronic Nicotine Inhalation and Angiotensin Peptides
AngII in RV, p=0.064 AngII in Lungs, p=0.077
Liquid Chromatography–Mass Spectrometry

15. Role of the RAS in Cardiac Disease
• RAS dysregulation is associated with
many disease states, including cigarette
smoking-induced pulmonary
hypertension (Han et al., Toxicol Appl
Pharmacol, 2001; Yuan et al., J Renin Ang Aldo
Syst, 2015; Givertz, Circulation, 2001).
• AT1R antagonism and ACE inhibition
reduced mortality in a large
retrospective clinical study of pulmonary
hypertension patients (Lahm et al., Chest,
2020).

16. Can inhibition of angiotensin receptor signaling prevent the elevation of
RVSP and associated cardiac remodeling caused by chronically inhaled
nicotine?
Role of Angiotensin Signaling
Alzet osmotic minipump delivery of losartan
(SQ; 5.0 - 6.5 mg/kg/d; model 1004)
± Nicotine exposure
±Losartan AT1R Blocker
-1 0 2 4 6 8 weeks
❶ BP telemetry probe implantation (DSI)
❷ Ultrasound echocardiogram (LV and RV)
❸ Right heart catheterization (RVSP)
❶ ❷
❷ ❸
Systemic BP and HR recording
Sacrifice

17. Losartan Blocks Nicotine-induced Increases in RVSP
****p<0.0001

18. Losartan Ameliorates Nicotine-induced RV Remodeling
* p<0.05; p**** p<0.0001
B

19. Nicotine and Losartan did not alter LV Structure or Function

20. Nicotine and Losartan did not affect Systemic Blood Pressure

21. • Functional α7-nicotinic acetylcholine receptors (nAchRs) are expressed on
smooth muscle cells, fibroblasts, endothelial cells, and cardiomyocytes.
• α7-nAchRs regulate cancer cell proliferation and ACE2 expression (Paleari, Cell
Prolif, 2008; Leung, Eur Resp J, 2020).
• Evidence of cross-talk between AngII and α7-nAchR signaling pathways (Li, et
al. ATVB, 2016).
Are α7-nAchR KO mice resistant to the effects
of chronically inhaled nicotine?
o Acrα7- mice from Jackson Labs (global KO)
o Exposed to inhaled nicotine for 8 wks
Role of Nicotine Receptor Signaling

22. Nicotine Effects are α7-nAchR Dependent
WT 7-nAChR KO
0
10
20
30
40
50
RVSP
(mmHg)
***
*
WT 7-nAChR KO
20
25
30
35
Fulton
Index
[RV/(LV+S)*100%]
Air
Nicotine
*
*p<0.05
***p<0.001

23. Summary
• Mice exposed chronically to inhaled nicotine developed increased
RVSP indicative of pulmonary hypertension, associated with RV
remodeling.
• RV changes were associated with activation of the RAS in the RV,
including increased ACE expression.
• Effects of nicotine on RVSP and RV remodeling were prevented by
AT1R blockade using losartan.
• Pulmonary hypertension and RV response to nicotine were
mediated by the α7-nicotinic acetylcholine receptor.

24. Acknowledgments
LSUHSC Department of Physiology
Nicholas D. Fried (MD/PhD student)
Anna Whitehead (MD/PhD student)
Joshua M. Oakes, PhD (Postdoctoral Fellow)
Charlotte S. Pearson (Research Associate)
Thomas D. Lobell (Research Associate)
Kandasamy Neelamegam, PhD (Postdoctoral Fellow)
Xinping Yue, MD, PhD (Co-PI)
Nicholas W. Gilpin, PhD (Co-I)
LSUHSC Department of Pharmacology and Experimental Therapeutics
Tamara Morris (PhD student)
Jiaxi Xu, PhD (Postdoctoral Fellow)
Eric Lazartigues, PhD (Co-PI)
Funding
NHLBI 1R01HL135635
NHLBI 1R01HL135635-S1

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