Obesity is described as an abnormal or excessive accumulation of fat that is a health problem. This condition has grown to become widespread in the United States. According to statistics collected by the Centers for Disease Control and Prevention (CDC) in 2017-2018, over 42% of US adults and 19% of young people in the US are obese.
Unfortunately, obesity rates in adults and children continue to rise. From 1975 to 2016, the global prevalence of overweight or obese children and adolescents between the ages of 5 and 19 increased more than fourfold, from 4% to 18%. Obesity is generally thought to be caused by eating too much and exercising too little, however recent studies suggest that other factors may be at play.
A Clemson University research team is taking steps to understand the link between certain naturally occurring enzymes in the body and their role in managing obesity and controlling liver disease.
Three Clemson researchers and colleagues at Emory University School of Medicine looked at male mice lacking the Cyp2b enzyme and how the absence of the enzyme affected the metabolism of mice.
According to William Baldwin, a professor and program supervisor at Clemson’s Department of Biological Sciences, the study was based in part on a simple observation: male mice without the Cyp2b enzyme were gaining weight. Cyp2b-null mice did not show the same effect.
“We noticed that our Cyp2b-null mice were heavier,” said Baldwin, a professor in the biological sciences department. “They are more prone to obesity - at least diet-induced obesity - especially in men than wild-type mice, and we’ve been trying to figure out why this is happening.”
While the observation that informed the researchers was quite simple, it turned out that understanding the interactions behind weight gain would be much more complex.
“It would be nice if there was a nice, simple answer,” Baldwin said, “but there probably isn’t a nice, simple answer.”
Variety of roles
Baldwin noted the complexity of several chemical processes involving the enzyme CYP, which is part of a superfamily of enzymes that performs a number of functions in humans. According to him, Cyp2b enzymes help to metabolize certain toxins and drugs to eliminate them from the body.
But the same CYP enzymes have other jobs. “They metabolize bile acids; metabolizes steroid hormones; they metabolize the polyunsaturated fats in our diet, ”Baldwin said. “It simply came to our notice then. If you have a high-fat diet, it may inhibit your metabolism. Of course … drugs could inhibit fat metabolism, it could affect steroid metabolism and so on. ”
The researchers also looked at the association between “disturbed lipid profiles” and disease.
Susceptibility to disease and general health are severely affected by changes in lipidoma, the researchers noted. High-fat diets, such as the Western diet, cause obesity and drastically alter liver lipidoma, and disturbed lipid profiles are associated with specific liver diseases, such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH).
The impact of age and diet
Baldwin has previously conducted research examining the link between diet and environmental toxins. The latest study looked at how aging and diet affect these metabolic processes.
“What makes us a poor diet?” What makes us old? That’s about it, “Baldwin said of the latest research. “We look at these enzymes; what could happen over time to our profiles in this mouse model compared to just a wild mouse. What could happen over time to a high-fat diet, what could happen as you get older, and how does this mouse model, which does not have these enzymes, differ from one that has these enzymes? ”
Baldwin simply said, “One of the things I’ve seen, and it’s not surprising, is that aging is bad. It is more difficult for mice to adjust body weight. He’s getting fat. Their weight is more white adipose tissue [connective tissue mainly comprising fat cells]. … And some of these things were a little worse for mice that lacked Cyp2b enzymes. They were a little heavier. They had a little more fat than their counterparts. Their livers were a little bigger and a little less healthy. So they had a lot of those things that we associate with age. “
The diet also had an impact on the health of the mice.
“Of course, the diet didn’t help either,” Baldwin said. “It’s the same thing: a bad diet caused weight gain and it was a little worse. [Cyp2b-null] mice, probably due to poor metabolism. ”
He said the exact mechanism by which the Cyp2b enzyme works is not fully understood.
“It removes an enzyme that helps metabolize them, but I don’t think it’s really important to help get rid of fat, but to inform the body that fat is there. It probably produces signaling molecules that say, “Hey, we have to decide what to do with this fat; we need to distribute this fat. That kind of information. That’s the decent thing to do, and it should end there. “
Differences in people
Baldwin said his current research takes a closer look at the mechanisms at play and how they differ in a human model from mouse studies.
He said the research, which will be part of an unpublished paper, indicates that mice and human enzymes probably do not work the same way. “The human enzyme seems to cause us to keep some of the fat in the liver, and the mouse enzyme seems to lead to white adipose tissue. There are indications here in this paper that this is the case, “Baldwin said.
A grant from the National Institutes of Health supported the research.
Reference: “Age and diet-dependent changes in hepatic lipidomic profiles of phospholipids in male mice: accelerating age in Cyp2b-Null mice” by Melissa M. Heintz, Ramiya Kumar, Kristal M. Maner-Smith, Eric A. Ortlund and William S Baldwin, March 29, 2022, The diary of lipids.
DOI: 10.1155 / 2022/7122738