Researchers from Kyushu University, located in Japan, have managed to identify an antioxidant compound with the potential to aid in maintaining the regenerative capacity of muscles as individuals age. The study focused on how a molecule called LASSS influences a crucial protein for muscle repair.
The investigation, published in Scientific Reports this July, examined the impact of the aging process on hepatocyte growth factor, known by the abbreviation HGF. It was observed that this protein undergoes chemical modifications over the years, which decreases its effectiveness in the muscle recovery process.
The scientists tested two sulfur-based compounds and found that LASSS not only prevented damage caused by nitration but also increased HGF's aptitude to bind to cells involved in tissue regeneration.
The premise of the work arose from the finding that the loss of muscle mass and strength associated with age does not necessarily result from the cessation of HGF production by the organism. The core of the problem lies in possible chemical alterations that the protein may undergo, compromising its function.
This alteration, known as nitration, impairs the signal transmitted by HGF to the cells responsible for muscle reconstruction. Thus, the Japanese team sought methods to protect this protein against this wear and tear, using antioxidants capable of interrupting deleterious chemical reactions.
The researchers selected two compounds containing three sequentially linked sulfur atoms: trithioglutathione, or GSSSG, and trithiolipoic acid, named LASSS. Both demonstrated the ability to reduce nitration at sensitive sites on HGF.
However, even after this initial result, merely blocking the chemical damage proved insufficient to completely restore the interaction between the protein and muscle repair cells. A notable difference emerged when the scientists increased the concentration of the analyzed compounds.
In this new scenario, LASSS exhibited a more pronounced effect. In addition to inhibiting the harmful modification of HGF, the compound doubled the protein's efficiency in connecting to the c-met receptor, a vital cellular structure for muscle regeneration processes.
The team suggests that this finding may indicate an action that transcends mere antioxidant protection. The hypothesis raised by the researchers is that LASSS may interact directly with HGF, inducing a structural change that makes the protein more robust and functional.
Subsequent tests were conducted on mouse models exhibiting muscle atrophy. These experiments revealed that the compound reduced nitration caused by muscle inactivity, although this effect requires confirmation in human tissues.
This discovery is seen as a future potential in combating sarcopenia, the term used to describe muscle loss associated with aging. This condition can begin to manifest from the age of 30 and tends to progress more rapidly after 60, increasing the risks of falls and hindering mobility.
More extensive studies will be necessary to evaluate the impacts of LASSS in elderly animals and subsequently verify its applicability in humans. The researchers also point out that this approach may be useful in other conditions of muscle loss, such as those related to chronic diseases.
