# Nicotine and alcoholic liver disease

> **NIH NIH R01** · MARSHALL UNIVERSITY · 2020 · $358,050

## Abstract

ABSTRACT
Alcohol abuse is a significant global health problem. Chronic alcohol drinking can induce alcoholic liver disease,
which ranges from steatosis (fatty liver) to steatohepatitis, fibrosis and cirrhosis. About 90% of heavy alcohol
drinkers develop alcoholic fatty livers (AFL), an onset of alcoholic liver disease. Recently, we found that
CYP2A5 (CYP2A6 in humans) is induced by chronic ethanol feeding and CYP2A6 is elevated in alcoholic
patients. CYP2A5/6 is a major nicotine metabolic enzyme. Alcohol and tobacco are frequently co-abused and
tobacco smoke can increase AFL. We found that nicotine, a major addictive forming alkaline in tobacco smoke,
can enhance AFL and hypertriglyceridemia (HTG), which was observed in WT mice but not in cyp2a5-/- mice.
PPARα-regulated FGF21 is a novel metabolic regulator highly expressed in liver. We observed a constitutive
elevation of hepatic PPARα-FGF21 in cyp2a5-/- mice. Ethanol-induced HTG observed in pparα-/- mice with an
extremely low serum FGF21 can be blocked by the treatment of rFGF21. Ethanol/nicotine-induced AFL was
more pronounced in liver-specific FGF21 KO mice. These results suggest that FGF21 may play an important
role in FGF21 modulates cellular activity through FGF receptor 1 (FR1), which is mainly expressed in adipose
tissues and to a much lesser extent in liver. We didn’t observe any difference in AFL and HTG between liver-
specific FR1 KO mice and their WT control mice, suggesting that in our model the more important might be
adipose FR1 but not liver FR1. Liver FGF21 can be released into blood to act in an endocrine manner. FGF21
can stimulate adipocytes to secret adiponectin, which in turn acts on the liver to ameliorate AFL. In AIM 1, we
will reintroduce CYP2A5 back to cyp2a5-/- mice via AAV8 to validate the essential role of CYP2A5 in the
nicotine-enhanced AFL and HTG and apply cotinine and antioxidant to examine the role of CYP2A5-produced
nicotine metabolites and oxidative stress in the nicotine-enhanced AFL and HTG. In AIM 2, we will examine the
role of a PPARα-FGF21 axis in the nicotine-enhanced AFL and HTG by applying pparα-/-/cyp2a5-/- mice, liver-
specific FGF21 knockout mice and PPARα specific agonist WY-14,643. In AIM 3, cell-cell interaction in cell co-
culture system of adipocytes and hepatocytes will be examined to reflect organ-organ interaction between
adipose tissue and liver. Adiponectin knockout mice will be treated with rFGF21 to evaluate if liver FGF21
exerts its action in adipose tissue through adiponectin i.e. the PPARα-FGF21-adiponectin to regulate nicotine-
enhanced AFL and HTG. At last, adiponectin and CYP2A5 double knockout mice will be applied to investigate
the role of adiponectin in the observation that nicotine-enhanced AFL and HTG was observed in WT mice but
not in cyp2a5-/- mice.

## Key facts

- **NIH application ID:** 9967908
- **Project number:** 5R01AA024723-07
- **Recipient organization:** MARSHALL UNIVERSITY
- **Principal Investigator:** Yongke Lu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $358,050
- **Award type:** 5
- **Project period:** 2016-07-15 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9967908

## Citation

> US National Institutes of Health, RePORTER application 9967908, Nicotine and alcoholic liver disease (5R01AA024723-07). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9967908. Licensed CC0.

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