News di Alcologia

Da una ricerca condotta negli Stati Uniti e pubblicata sulla rivista Alcoholism: Clinical and Experimental Research, è emerso

che le alterazioni di coscienza derivanti dal consumo di alcol dipendono da un gene CYP2E1, che influenza la velocità con cui

il nostro cervello metabolizza l'alcol.
La scoperta, frutto dello studio di Kirk Wilhelmsen della University of North Carolina, potrebbe suggerire nuove terapie

contro l'alcol-dipendenza.
La ricerca.
Gli esperti hanno confrontato il Dna di 200 coppie di fratelli e sorelle e poi chiesto loro di bere degli alcolici e di dire

dopo quante bevute sentissero uno stato di alterazione.
I ricercatori hanno identificato due diverse versioni del gene CYP2E1, sul cromosoma 10, che produce un enzima che

metabolizza l'alcol che va a finire nel cervello.
Le due forme di questo gene producono due versioni differenti dell'enzima, di cui una molto veloce a digerire l'alcol. È

emerso infatti che all'interno del campione, le persone che hanno questa seconda versione di CYP2E1, percepiscono uno stato

di alterazione entro tempi brevi, perché l'alcol appena arriva nel cervello viene metabolizzato da CYP2E1.

Testo dell'articolo originale

CYP2E1 gene found to be associated with alcohol response in the brain

A new gene, CYP2E1, has been found to be linked to an individual's sensitivity to alcohol
•The gene CYP2E1, which is located on the terminal region of chromosome 10, plays a major role in the metabolic processing of

alcohol
•New findings show that this gene is linked with a low sensitivity to alcohol and increased risk for alcoholism
•CYP2E1 could therefore be used as a predictor for those who are at risk for alcoholism
The research into how alcohol reacts with the brain is a complex one, and has been relentlessly studied for many years. But a

new study has shown, through linkage and association analysis on various family groups, that a gene originally thought to be

primarily associated with ethanol metabolism, may be significantly involved in dictating an individual's alcohol sensitivity.
The results will be published in the January 2011 issue of Alcoholism: Clinical & Experimental Research and are currently

available at Early View.
According to Kirk Wilhelmsen, one of the author's of the study and Professor at the University of North Carolina at Chapel

Hill's Department of Genetics and Neurology, the researchers were led to the CYP2E1 gene because it was at the terminal end

of chromosome 10, which was the region in which linkage was detected.
"Linkage asks the question, in this case for the whole genome, whether siblings that have similar (or different) phenotypes

have inherited the same (or different) chromosomes from their parents," says Wilhelmsen. "What is important about these

studies is the strength of association is very strong compared to the vast majority of associations between DNA variations

and behavioral traits."
Wilhelmsen added that due to CYP2E1's terminal position on the chromosome, and the tendency regions of other chromosomes to

swap small sections of DNA (in a process called crossing over), there are three distinct haplotypes of the gene. "We can make

predictions about the level of response to alcohol an individual will have based on determining which haplotypes an

individual has," he said. "Figuring out which specific variations are important would be icing on the cake. It is likely that

a combination of variations is what is important."
The data was collected from 237 college student siblings that had one alcohol-dependent parent, but were not dependent

themselves. This allowed the researchers to explore an area of little research, which is the relationship between the

genetics of an individual and their alcoholic behavior.
"Alcoholism is a genetically influenced behavior, but gene discovery for behavior diseases are difficult for many reasons,"

said David Goldman, the Chief of the Lab of Neurogenetics at the National Institute on Alcohol Abuse and Alcoholism. "Even if

one gene is important, as now appears to be the case for this metabolic gene CYP2E1, there may be multiple functional

variants in the gene. We probably don't even know the identities of the players."
Goldman also added that this discovery while important in establishing a possible genetic predictor for alcoholism, there are

still many questions left unanswered that can only be solved by more research into the area.
Wilhelmsen agreed. "[But] what is much more important than knowing this piece of information is that this suggests how our

brains sense alcohol. The identification of CYP2E1 suggests three mechanisms."
"Two of these mechanisms are paradigm changers," he said. "The most exciting possibility is that this result indicates that

alcohol induces production of more free radicals in the brain in people that are more sensitive to alcohol."

Kirk Wilhelmsen
Alcoholism: Clinical & Experimental Research
http://www.eurekalert.org/pub_releases/2010-10/ace-cgf101210.php