Human Growth Hormone Shown to Activate Gene That Promotes Tissue Healing
It is said that some celebrities include human growth hormone (HGH) in their anti-aging or beauty regimen. Research out of the University of Illinois at Chicago (UIC) showed that one of the ways the substance may help fight the effect of aging is by activating a gene that plays a role in the healing of the damaged tissue.
The growth hormone, a substance produced by the pituitary gland in the head, is crucial for growth and development. Its benefits in adults include reduction of body fat, an increase in lean body mass, and improvement of bone density. Their levels will start to decrease as part of the aging process, bringing certain unwanted changes.
In the UIC study, researchers found that HGH activated a gene known as Foxm1b, which is believed to be involved in the repair and rejuvenation of tissues in the body.
“Growth hormone levels decline as we grow older; as a result, the Foxm1b gene stops working and our bodies are less capable of repairing the damage,” said Robert Costa, professor of biochemistry and molecular genetics at UIC.
The research, which seemed to give a hint on why aging occurs, was published in the journal Hepatology.
Studying HGH effects
Scientists set out to investigate the ability of growth hormone to promote cell proliferation. Previous research had shown that the substance promoted cell division, leading to benefits such as increased muscle mass and greater bone density.
To study HGH effects, the focus was placed on Foxm1b. This gene is involved in the division, multiplication, maturity, and death of mammalian cells. Its level of activity reaches its peak in young animals and then declines with age.
Researchers had shown in earlier studies that the human Fox1m gene helped to restore Foxm1b proteins when inserted in mice. The livers of the animals, which had been partially removed, grew back at a pace comparable to that seen in young mice.
Of all organs in the body, the liver is the only one capable of fully restoring itself from mature cells.
The scientists were interested in knowing more about the growth hormone’s mechanism of action at a molecular level.
Increased Foxm1b activity
Costa and his team studied the effects of HGH in aged mice (12 months old) and young mice (two months old). They partially removed the livers of the older mice, after which the animals were given growth hormone injections.
Following the treatment, Foxm1b gene activity improved considerably in the aged mice, going by results of the histological tests and other tests. The amounts of substances – enzymes and proteins – that promote cell division increased drastically, with cell proliferation peaking at two days.
It was also observed that the livers of the aged mice restored at a rate seen in younger counterparts and were completely regenerated within a week.
In contrast, it took at least a month for the livers of aged mice which did not get HGH injections to fully regenerate. The activity of the Foxm1b gene remained at a low level similar to what is seen in old age and cell proliferation was slow.
The researchers also tested growth hormone in mice that had been genetically engineered to have disabled Foxm1b gene. They found that the injections did not promote regeneration in the animals whose livers had been partially removed.
“These results clearly demonstrate that Foxm1b is essential for growth hormone to spur liver regeneration,” Costa said.
It is feared that long-term growth hormone use can bring about unpleasant side effects. Costa, however, said that short-term use could be helpful for accelerating recovery from surgery and injuries in the elderly.
- “Growth Hormone Activates Gene Involved In Healing Damaged Tissue.” University Of Illinois At Chicago