It is well recognized that mothers who smoke during pregnancy increase the risk that babies are born prematurely and have a low birth weight. More recent research has found that fetal exposure to tobacco smoke increases the risk of pediatric obesity and adult chicken, but the mechanisms responsible for this are not understood.
Studies conducted by a team led by the University of Kentucky now suggest that maternal smoking increases at protein levels called chemerin – which is related to obesity in adults – in their newborns. The findings, reported by Kevin Pearson, Ph.D., and colleagues in Experimental physiology, suggests that smoking during pregnancy may have an impact on the epigenetic control of chemerin in the fetus and in the newborn, which subsequently increases the risk of obesity later in life. Describing the studies in a paper titled "Smoking during pregnancy increases the expression of chemerin in neonatal tissue," the researchers concluded: "Our data provides a potential new mechanism behind the increased risk of subsequent obesity in babies born to mothers who smoke during pregnancy ".
In the UK, 26% of adults and 20% of children are obese, which costs the company about 27 billion pounds a year, according to UK government figures cited by the Physiological Society. Obesity rates also continue to increase, suggesting that environmental factors other than exercise and genetics can contribute. In the U.S., nearly 35% of adults and 20% of children aged 6-19 are obese, which costs the US medical system. about $ 200 billion annually, the authors added. Although multiple factors play a role in the development of obesity and metabolic disorders, a potential contribution is in the womb environment during pregnancy. "
Chemerin is an adipoxin that regulates the differentiation of fat cells. Chemokine levels are high in people with obesity and those exposed to smoke, but if chemerin levels are changed in newborn babies exposed to cigarette smoke in the womb has not been investigated, the authors wrote. They examined the chemerin gene expression, taken from the feces of pregnant women, from circumcised babies of mothers who smoked during pregnancy, compared to neonates from non-smoking mothers. Foreskin is easy to collect and the team has previously shown that it has similar properties to tissues like fats that they could not have collected from newborns.
Tissue analyzes showed that chemerin expression was significantly higher in the predisposing tissues of children who had been exposed to cigarette smoke in the womb, compared to controls. Cells that were collected from infants born to smokers showed increased chemerin mRNA expression compared to isolated cells in non-smoker children, "they wrote. Chemerin levels were also elevated in primary dermal fibroblasts derived from smoking, which were grown in culture and were stimulated using an adipogenic cocktail.
Interestingly, further analyzes have shown that chemerin DNA methylation was lower in all tissues of newborns born to mothers who smoke, suggesting that epigenetic mechanisms may be involved in smoke-induced changes in chemerin gene expression. "Current data support a potential mechanism in which children or adults are exposed in the womb to cigarette smoke could show more obesity rates later in life, the team concluded. "Others have shown that although newborns have been exposed in the womb to cigarette smoke tend to be smaller, have higher rates of obesity later in life suggesting change in development programming … "
The team admitted that their study has limitations, not least because the results can not be extrapolated to female offspring. Moreover, the researchers write: "… we make these measures in epidermal / dermal samples and we anticipate that adipose tissue would respond in a similar fashion, which may not be the case. Due to the limited availability of tissues, we were only able to evaluate the expression of chelate DNA and chemerin mRNA expression, rather than the expression of the protein in our samples, so that it should be investigated in the future. "However, they commented," Despite the current limitations, new evidence for a link between maternal smoking during pregnancy and increased expression of chemerin mRNA. "
The team aims to assess the effects of other maternal behaviors on the health of the offspring. "Our long-term plan is to study the impact of exercise during pregnancy and its ability to improve health outcomes in chickens," said Dr. Pearson. However, as we began to turn our work from lab animals to humans, it quickly became quite a fact that a fairly large proportion of the pregnant population delivered to our hospital continued to smoke cigarettes during pregnancy. Thus, we intend to investigate the mechanisms for which babies born to smokers are at risk of further illness. In the future, we would like to work on ways to improve smoking cessation programs or ways to increase the level of physical exercise in smokers as a way to combat the negative outcomes of children, but we really really start scratching surface in this area. "