Ageing -- the process of becoming older -- is basically an unavoidable biological process. Now scientists have made a breakthrough in developing anti-ageing drugs. The study, published in Science, shows that a compound called nicotinamide mononucleotide (NMN) has a dramatic rejuvenating effect on aging mice. The study is led by Dr David A. Sinclair from Department of Genetics, Paul F. Glenn Center for the Biology of Aging, Harvard Medical School. Dr Sinclair and the team looked at a molecule called NAD+, the oxidised form of the chemical nicotinamide adenine dinucleotide. NAD+ is present in every cell in the body. In previous work, the team discovered that the levels of NAD+ decline as people age regardless of their health. Moreover, increasing NAD+ levels in older mice made them look like younger mice. This work and many other studies highlighted the anti-ageing properties of NAD+, suggesting that NAD+ supplementation could be a treatment for aging. For the current study, the team continued exploring the working mechanism of NAD+ and found that NAD+ plays an important role in regulating protein interactions that control DNA repair. When the researchers treated younger mice and older mice with NMN, which is a booster of NAD+, the animals' cells became more capable of repairing DNA damage caused by radiation exposure or old age. "The cells of the old mice were indistinguishable from the young mice, after just one week of treatment," Dr Sinclair stated. The team plans to test NMN in clinical trials within six months. Accumulated DNA damage is a major cause of aging and cancer. DNA damage can occur when a cell divides. Both normal metabolic activities and environmental factors such as radiation, plant toxins, and viruses can cause damage to DNA. In most cases, DNA damage can be repaired because cells have a variety of repair strategies. One is an enzyme called PARP1, short for poly(adenosine diphosphate–ribose) polymerase 1. The researchers found that NAD+ seemed to boost the activity of PARP1. Thus, low NAD+ levels seen in old people could decrease PARP1's ability to repair damaged DNA. "NAD+directly regulates protein-protein interactions, the modulation of which may protect against cancer, radiation, and aging," the researchers concluded. In their paper, the researchers detailed how NAD+ works to impact PARP1 activity and keep cells young. Other researchers of the study included Jun Li, Michael Bonkowski, Sebastien Moniot, Dapeng Zhang, Basil Hubbard, Alvin Ling, Luis Rajman, Bo Qin, Zhenkun Lou, Vera Gorbunova, L. Aravind, and Clemens Steegborn. In addition, Cusabio offers PARP1 and NAD+ related products and Recombinant FGFR1.
