DNA Repair with NMN
DNA repair is crucial for cell life and its survival. It also prevents cancer and the ability of the cells to repair damaged DNA decays with age for reasons not fully understood. The new researches suggest that why and how the ability of the body fixes the DNA decline with time. In DNA repair, NAD is a signalling molecule which is the key regulator of protein-to-protein interactions. If confirmed in further animal studies and in the human, the researches can help to find the ways to therapies that avert DNA damage linked with cancer treatment and ageing that involves some types of chemotherapy and radiation exposure which along with the tumours can cause the substantial DNA damage in the healthy cells of the human body.
How NMN help in DNA repair: Recent Research
The team of Harvard Medical School conducted a study that was published in the year in 2017 in Science. This study found that there is a link between NAD+, DBC1 and PARP1 with the help of the embryonic kidney cells of humans. This study confirmed that When NAD+ is prevalent; the PARP1-DBC1 complexes will be reduced. Now, the researchers have the goal to determine if this link could be induced to animals. They found that the levels of NAD+ were lower in the liver in the older mice as compared to the younger mice. In additions, researchers found that the older mice had lower levels of PARP1 activity and higher amount of PARP1 complexes and DBC1 bound.
When the mice drank the supplemented water of nicotinamide mononucleotide (NMN) for around one week, their NAD+ levels increased that in turns disrupted the DBC1-PARP1 in both young and old mice. In the older mice, NMN restored the PARP1 activity that enables it to perform the function properly as a protein for DNA-repair.
DNA also gets damaged by radiations from the UV sun exposure and cancer treatment as well. In an additional experiment, when gamma irradiation was exposed to older mice, it causes severe DNA damage and loses the RBC (red blood cells) and WBC (white blood cells). However, those mice who received NMN supplement had a reduction in the DNA damage. They were protected against the radiation-induced cell loss.
All these results show that NMN can protect radiation-induced cells, DNA damage that leads to DNA repair through the mechanism of reducing the capability of DBC1 to fix to PARP1 and boosting PARP1 and NAD+.
According to one study that was published in Nature in 2020 found the same results from cell culture experiments. The cell line was used by researchers that expressed XRCC1 (1 protein that is involved in damaged DNA repair). The activity of XRCC1 increases due to PARP1 when DNA damage occurs. When the cells are damaged due to laser micro-irradiation, nicotinamide riboside (NR) and NAD+ precursors NMN were introduced. Researchers found that the existence of NAD+ led to an upregulation XRCC1 and PARP1 to repair DNA. The findings of these studies have produced the hopeful results the research thus far has only been done with animals and cell culture.