1. The relationship between skin aging and mitochondria
The skin, the largest organ in the human body, has a high turnover rate, with a constantly regenerating epidermis whose constant renewal depends on the rapid proliferation of its progenitor cells. Epidermal progenitor cells are highly proliferative and metabolically active, and are dependent on adenosine triphosphate (ATP) for energy requirements.
Adenosine triphosphate is a nucleotide that stores and transmits chemical energy as the "molecular currency" of intracellular energy transfer. The reason why it can provide energy is because its molecular structure can be written as A-P~P~P, where "~" represents a special chemical bond called a high-energy phosphate bond. When high-energy phosphate bonds are broken, a large amount of energy is released.
Mitochondria, as a double-membrane organelle, exist in the cytoplasm of almost all eukaryotic cells. While ATP is mainly produced by oxidative phosphorylation (OXPHOS) in mitochondria, the bioenergetic center of eukaryotic cells, this double-membrane-bound organelle is involved in energy production, fatty acid oxidation (FAO), heme and steroid biosynthesis, apoptosis Essential functions such as apoptosis and calcium signaling.
Natural byproducts of OXPHOS include reactive oxygen species (ROS), such as superoxide anion, singlet oxygen, and peroxides, which damage macromolecules and cellular structures. Oxidative damage caused by mitochondrial ROS production is an important molecular basis for various pathophysiological conditions, including aging and cancer.
2. The effect of photoaging on skin aging
In addition to the inevitable time-induced changes, skin is also prone to photoaging due to long-term exposure to the sun's UVA and UVB radiation.
Ultraviolet rays in sunlight can enhance the activity of tyrosinase, thereby increasing the synthesis of melanin and accelerating skin aging. Furthermore, since photoaging is a cumulative process, it is more pronounced in older adults who are regularly exposed to prolonged sunlight. Both intrinsic and environmental factors affect the epidermal and dermal layers of the skin. Histologically, chronological aging is characterized by marked epidermal thinning manifested by dryness and wrinkling.
In contrast, photoaged skin has a thick, leathery appearance with deeper wrinkles and uneven pigmentation. At the molecular level, aging skin is characterized by damaged mitochondria, loss of mtDNA, high ROS levels, and oxidative stress in the dermis and epidermis. Aging affects the skin's protection against physicochemical and biological aggression, as well as its thermoregulatory, sensory, immune and hormonal functions.
3. Physical sunscreen and chemical sunscreen
In general, sunscreens are divided into physical sunscreens and chemical sunscreens:
Physical sun protection
Avoid traveling when the sun is strongest, usually from 9:00 am to 2:00 pm, when the ultraviolet rays are relatively strong.
When going out, you can prepare a sun protection clothing, or prepare a parasol, or wear sunglasses, masks or something.
Chemical sunscreen
Chemical sunscreens are what we know as sunscreen. Sunscreen forms a film on the surface of our skin to protect against UV rays.
When choosing a sunscreen, it is best to choose one that protects against both UVA and UVB.
4. The relationship between mitochondria and skin diseases
In addition to skin aging and cancer, mitochondrial dysfunction has been associated with a variety of common and rare skin disorders, which can be broadly divided into three categories: skin manifestations of primary mitochondrial disorders, skin disorders caused by mitochondrial dysfunction, and genetic skin disorders Performance.
Clinically, these disorders can manifest as hair abnormalities, inflammation, rashes, hypopigmentation and hyperpigmentation, and cyanosis (ie, blue-eyed extremities). Most of the underlying molecular mechanisms have been identified, mainly involving dysfunctional OXPHOS and high ROS production, mtDNA mutations, imbalance between mitochondrial biogenesis and mitophagy, and aberrant expression levels of nuclear-encoded mitochondrial proteins. In addition, dysregulation of other mitochondrial metabolic pathways and structural proteins has also been implicated.
It can be seen that the relationship between mitochondria and skin is very close. It is not limited to the skin aging problem that we are most concerned about. In research, scientists are also more concerned about the relationship between mitochondria and skin diseases and cancer.
As the age increases, the number of mitochondria in the human body will gradually decrease, and the efficiency of mitochondrial energy supply will also be much lower than before. Then the solution is to improve the efficiency of mitochondrial work, or increase the number of mitochondria in the human body.
That said, promoting mitochondrial biogenesis is important, akin to the feeling of refurbishing an entire old workshop to produce a greater volume of new machinery.
5. NMN can slow down skin cell aging
Cell mitochondria can directly use NMN, NMN can significantly increase mitochondrial NAD+ level, and NAD+ level determines the aging speed of human cells and the strength of cell repair ability.
NAD+ acts as a coenzyme in the mitochondria to promote metabolic balance, NAD+ plays a particularly active role in metabolic processes such as glycolysis, TCA cycle (aka Krebs cycle or citric acid cycle) and electron transport chain, is How cells get energy. Aging and a high-calorie diet can reduce the level of NAD+ in the body. Taking NAD+ boosters also reduced diet- or age-related weight gain and improved exercise capacity in aged mice, the study showed. NAD+ binds to enzymes and transfers electrons between molecules. Electrons are the building blocks of cellular energy. NAD+ acts on cells like charging a battery. When the electrons are used up, the battery dies. In cells, NAD+ facilitates electron transfer, which provides energy to cells. In this way, NAD+ can decrease or increase enzyme activity, promoting gene expression and cell signaling.
NAD+ helps control DNA damage. As organisms age, some adverse environmental factors, such as radiation, pollution, and imprecise DNA replication, can damage DNA. This is one of the theories of aging. Almost all cells contain "molecular machinery" to repair this damage. This repair consumes NAD+ and energy, so excessive DNA damage depletes precious cellular resources. An important DNA repair protein, PARP, also depends on NAD+ to function. Normal aging leads to the accumulation of DNA damage in the body, increased RARP, and therefore lower NAD+ concentrations. Any step of mitochondrial DNA damage exacerbates this depletion.
We must admit that in terms of technology, NMN products can be described as completely superior to general "anti-aging" beauty products. Because NMN products play an anti-aging effect "from the inside out", from the perspective of repairing human DNA, solve the problem from the root.
