What Is the Connection Between Obesity and Genetics?

The obesity gene refers to that the protein encoded by the gene is a component of an appetite and energy balance regulation pathway, and the imbalance of this pathway directly or indirectly causes the accumulation of body fat and weight gain.

Obesity gene

The obesity gene refers to that the protein encoded by the gene is a component of an appetite and energy balance regulation pathway, and the imbalance of this pathway directly or indirectly causes the accumulation of body fat and weight gain.

Chinese name

Obesity gene

Foreign name

Obesity genes

Introduction

The essential

This spring, when the first key hidden behind obesity

Five identified obese genes

Scientists have cloned five genes related to human appetite and weight regulation, namely OB gene, LEPR gene, PC1 gene, POMC gene and MC4R gene.

1. The human OB gene is located on the long arm of chromosome 7 (7q31.3). It is a single copy in the human genome, with a total length of about 20 kb, containing three exons, and a total length of 4240 bp. OB gene only

When body fat content increases, leptin synthesis and secretion increase; leptin binds to its receptor to produce leptin-Rb, which in the hypothalamus induces enhanced expression of POMC genes in neural cells; strong expression of POMC leads to the concentration of its breakdown product -MSH Increased; -MSH in turn binds to its receptor MC4R, producing a physiological effect of suppressing appetite. Inhibited appetite results in decreased body fat content and decreased leptin synthesis and secretion, resulting in reduced binding to LEPR

FTO gene

In 2007, British scientists discovered the FTO gene, which is closely related to obesity. People with more FTO genes in their bodies had an average weight of 3 kilograms more than others. In this study, for the first time, scientists discovered how "obesity genes" such as the FTO gene affect a person's weight and weight.

Research by scientists such as Ulrich Rueter of the University of Dusseldorf in Germany also found that the "FTO" gene is a gene associated with obesity, also known as the "obesity gene". Scientific research shows that FTO gene can inhibit metabolism, reduce energy consumption efficiency, and lead to obesity. Therefore, the research on FTO gene and its expressed protein has become a hot spot in the biomedical field in the world.

The discovery of FTO stems from a search for genes related to type 2 diabetes. The researchers conducted a sample analysis of approximately 39,000 people and concluded that people carrying two copies of an FTO variant gained about 3 kilograms in weight. This is about one The first clear example of a common obesity gene. Researchers found in laboratory mice that the brain's hypothalamus, which is used to help regulate the body's energy balance, has very high levels of FTO. Mice with a 60% reduction in FTO in the hypothalamus tended to refuse to eat compared to mice in the control group. This means that FTO may play an important role in controlling appetite.
Beijing Life Science Research Institute and Tianjin University researchers jointly analyzed the crystal structure of the FTO gene expression protein for the first time in the world, and further proved that the protein is a type of DNA demethylase (the The groundbreaking research results have been published in the well-known international academic journal Nature published on April 8, 2010). ^[1]

Obesity has genetics

In 2009, Nature Genetics published a research report that analyzed six newly discovered genes. These six newly discovered genes control obesity by affecting the nerve center. The research team analyzed 32,000 individuals through genome-wide association analysis, screened out a large number of obesity-related mutations, and obtained 6 new obesity genes. The six genes are: TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2, and NEGR1. Gene expression analysis found that all six genes were active in brain cells. The two genes FTO and MC4R discovered in previous studies also have similar characteristics.

In addition to the obesity genes listed above, the scientists also cloned five genes related to human appetite and weight regulation, namely the OB gene, the LEPR gene, the PC1 gene, the POMC gene, and the MC4R gene.

OB gene

The human OB gene is located on the long arm of chromosome 7 (7q31.3). It is a single copy in the human genome. OB gene is only expressed in adipose tissue, and its coding product

Obesity affects dopamine secretion

Dopamine is known as the "brain information transmitter". It is a neurotransmitter in the brain and is mainly responsible for the transmission of excitement and pleasure in the brain. Studies have shown that diet can temporarily stimulate dopamine secretion in the brain. Previous studies have found that obese people have fewer dopamine receptor genes in the body than lean people.

Exercise affects obesity genes

American researchers say strenuous physical activity helps maintain weight, even for obese gene carriers.

Researchers said that a study of a group of Amish people found that people who carry the obese gene but actively participate in physical exercise have the same weight as non-obese carriers.

"When we studied the Amish who was most active in physical training, it suddenly felt like the genes had no effect," said Sauron Snitek at the University of Maryland. The results will be published in the Archives of Internal Medicine Internal Medicine ).

The results show that physical exercise can overcome the effects of the obesity gene, and this finding may provide the basis for related debates, namely, whether to change the diet structure or physical exercise to control obesity most effectively.

Researchers focused on 704 old-style Amish people in Lancaster County. People in this religion do not usually drive cars and do not use electricity in their homes. Snitek said that these people are engaged in different levels of physical exercise. Some farmers still use horse-drawn ploughs, while others are more common, including working in factories.

Snytek and Evadny Lampesaud of the University of Miami hope to use the research to draw conclusions to see if physical activity can compensate for the effects of obesity in these people. More than half of people of European descent carry this gene.

Those who carry double copies of the obese gene FTO have an average body weight that is almost 7 pounds heavier than the average person. Compared with non-obese gene carriers, the probability of obesity is about 70% higher.

Volunteers carry accelerometer devices to track and record their movements throughout the week. The researchers then compared their body mass index BM I and found that people who exercise less and carry the FTO gene are more likely to be overweight or obese.

However, FTO genes have no effect on body weight among people who exercise actively.