New study reveals protein's role in middle age weight gainScientists uncover key link between aging and middle age obesity. Credit: scitechdaily.com

A team of scientists from Nagoya University and other institutions in Japan have made a groundbreaking discovery about the causes of middle age obesity.

Their study found that changes in the structure of neurons in the hypothalamus, the part of the brain that controls metabolism and appetite, are responsible for the weight gain seen in middle-aged individuals.

The study focused on a protein called melanocortin-4 receptor (MC4R), which plays a crucial role in regulating metabolism and controlling food intake.

The researchers discovered that MC4Rs are concentrated in primary cilia, which are antenna-like structures that extend from certain groups of neurons in the hypothalamus.

As we age, these primary cilia become shorter, leading to a decrease in MC4Rs and ultimately resulting in weight gain.

According to Professor Kazuhiro Nakamura, lead author of the study, this mechanism is likely present in humans as well. He hopes that this finding will pave the way for new and effective treatments for obesity.

Obesity is a growing problem in today's society, and it becomes more prevalent as we age.

People who are overweight or obese are at a higher risk for chronic diseases such as diabetes and hyperlipidemia.

Previous studies have suggested that middle-aged weight gain is caused by a decline in overall metabolism due to aging, but the specific mechanism has remained unclear.

  1. To gain a better understanding of this process, the research team focused on the role of MC4Rs.

    These receptors are responsible for detecting overnutrition and triggering the body's metabolism and appetite regulation processes.

    The team found that MC4Rs are exclusively present in primary cilia of specific groups of neurons in the hypothalamus.

    To further investigate this phenomenon, the researchers compared the length of primary cilia in young and middle-aged rats.

    They found that primary cilia with MC4Rs were significantly shorter in middle-aged rats, leading to a decrease in metabolism and fat-burning capacity compared to young rats.

    The team also studied the effects of different dietary conditions on MC4R+ cilia.

    They found that rats on a normal diet experienced a gradual shortening of these cilia as they aged.

    However, rats on a high-fat diet had a much faster decrease in the length of their MC4R+ cilia, while those on a restricted diet had a slower decrease.

    One interesting finding was that rats on a restricted diet for two months showed a regeneration of MC4R+ cilia that had disappeared with age.

    The team also conducted experiments where they artificially shortened MC4R+ cilia in young rats, which resulted in increased food intake, decreased metabolism, and weight gain.

    In addition, the team administered a hormone called leptin, which is known to reduce food intake, to rats with artificially shortened MC4R+ cilia.

    Surprisingly, the rats showed no decrease in appetite, indicating a resistance to the effects of leptin.

    Dr. Manami Oya, the first author of the study, explained that this phenomenon, known as leptin resistance, is often seen in obese individuals.

    This resistance could be a result of the age-related shortening of MC4R+ cilia, which leads to a malfunction in the body's anti-obesity system.

    The study concluded that the age-related shortening of MC4R+ cilia is a major factor in middle-age obesity and could also lead to leptin resistance.

    The researchers suggest that dietary restriction may be an effective method to prevent and treat obesity.

    By maintaining a moderate eating habit, individuals may be able to keep MC4R+ cilia long enough to keep their anti-obesity system functioning properly as they age.

    Ann Castro
    Ann Castro Author
    Ann Castro carries a total of 7 years experience in the healthcare domain. She owns a Master’s of Medicine Degree. She bagged numerous awards by contributing in the medical field with her ground-breaking notions. Ann has developed her own style of working and known for accuracy in her work. She loves trekking. She visits new places whenever she gets free time.