Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alcohol increases hepatitis C virus in human cells

27.06.2003


Drinking may compromise treatment success



A team of NIH-supported researchers today report that alcohol increases replication of the hepatitis C virus (HCV) in human cells and, by so doing, may contribute to the rapid course of HCV infection. The researchers tested the actions of alcohol in HCV replicon--viral HCV-ribonucleic acid or HCV-RNAs that, when introduced into human liver cell lines, replicate to high levels. In separate laboratory experiments they showed that:

  • alcohol increases HCV replication at least in part by upregulating a key cellular regulator of immune pathways and function known as nuclear factor kappa B (NF-kappa B):

  • alcohol inhibits the anti-HCV effect of interferon-alpha (INF-alpha)therapy; and

  • treatment with the opioid antagonist naltrexone abolishes alcohol actions.


Wenzhe Ho, M.D., and Steven D. Douglas, M.D., Department of Pediatrics, University of Pennsylvania, and the Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, and colleagues in the Department of Psychiatry, University of Pennsylvania School of Medicine report their results in the July 2003 issue of Hepatology (Volume 38, Number 1, pages 57-65).

Speculating that alcohol somehow promotes HCV expression, the researchers relied on a recently available cellular system for studying the dynamics of virus replication (developed and provided to the investigators by Drs. C. M. Rice, The Rockefeller University, and Christoph Seeger, Fox Chase Cancer Center) to demonstrate for the first time that alcohol enhances HCV replicon expression at both the messenger RNA and protein levels. In the cell lines used for the study, the research team also showed that alcohol activation of NF-kappa B was responsible for increasing HCV expression. "Although the replicon system mimics only some aspects of HCV replication, we have identified at least a likely mechanism whereby alcohol increases viral load and thus may become an important cofactor in HCV severity," Dr. Douglas said.

"These findings are immediately useful to clinicians for counseling HCV-positive patients about alcohol use," said Ting-Kai Li, M.D., Director, National Institute on Alcohol Abuse and Alcoholism (NIAAA). "For clinical and basic scientists, they raise new research questions, many of which no doubt will be explored using the model and methods introduced today." NIAAA supported the experiments through a grant to Dr. Douglas, whose work also was supported by the National Institute of Mental Health and the National Institute on Drug Abuse (NIDA). The NIAAA and NIDA supported Dr. Ho’s work on the study.

HCV is an RNA virus of the flavivirus family that infects about 4 million U.S. residents and produces some 30,000 new infections each year. HCV typically escapes clearance by the immune system and leads to persistent, chronic infection in 70 to 85 percent of infected individuals, of whom fewer than 50 percent respond to IFN-alpha, the HCV therapy of choice. Over the long term, HCV infection can lead to cirrhosis, liver failure, and liver cancer. As a group, HCV-infected individuals are the major recipients of liver transplantation.

Clinicians have long observed a high incidence of HCV infection in heavy drinkers, including those without other risk factors such as intravenous drug abuse or history of blood transfusions. In addition, the virus is more likely to persist in heavy drinkers and to lead to such complications as cirrhosis and liver cancer. Suspected mechanisms for the latter effects include alcohol’s capacity to compromise immune function and enhance oxidative stress. The role of alcohol use in HCV acquisition has been more of a mystery.

During the 1990s, several studies reported higher blood levels of HCV in drinkers than abstainers and in habitual than infrequent drinkers. Further, drinking reduction was shown to diminish the number of virus particles in the blood. These observations led Dr. Douglas and his colleagues to pursue the role of alcohol in HCV replication.

Using the same replicon, Drs. Ho, Douglas and their colleagues also demonstrated that alcohol compromises IFN-alpha action against HCV and explored a plausible mechanism for alcohol’s role in HCV expression. Alcohol interferes with endogenous opiates, which have a key role in its addictive properties. The researchers found that the opiate receptor antagonist naltrexone, better known for its utility in helping alcoholism treatment patients to avoid relapse, not only blocked the promoting effect of alcohol on HCV expression but also diminished alcohol activation of NF-kappa B in these cells. "These data strongly suggest that activation of the endogenous opioid system is implicated in alcohol-induced HCV expression," the authors conclude.



For an interview with Dr. Douglas, please telephone 215-590-1978; for an interview with Dr. Ho, please telephone 215-590-4462. For an interview with NIAAA staff members, please contact the NIAAA Press Office. Publications and additional alcohol research information are available at http://www.niaaa.nih.gov.

The National Institute on Alcohol Abuse and Alcoholism, a component of the National Institutes of Health, U.S. Department of Health and Human Services, conducts and supports approximately 90 percent of U.S. research on the causes, consequences, prevention, and treatment of alcohol abuse, alcoholism, and alcohol problems and disseminates research findings to science, practitioner, policy making, and general audiences.

Ann Bradley | EurekAlert!
Further information:
http://www.niaaa.nih.gov/

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>