How PQQ Protects Mitochondria and Prevents Cell Damage in Auditory Cells
|
|
Time to read 7 min
Note From Dr. Pendleton
This article is my attempt at a simplified summary of a scientific paper I found interesting. I’m passionate about sharing scientific knowledge in a way that’s accessible to everyone. However, it's important to remember that many scientific studies, including this one, may not directly apply to you, let alone all people. For example, some studies are conducted on animals or involve small sample sizes, which limits the generalizability of the results. My goal is to present the information responsibly and in layman’s terms, so please keep in mind that the findings should be interpreted with care.
Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on this website. The information in this article is based on a scientific review and should not be used as the sole basis for treatment decisions. Always consult with a healthcare professional before starting any new treatment or therapy.
Overview
This scientific summary is based on the research paper titled Pyrroloquinoline quinone (PQQ) protects mitochondrial function of HEI-OC1 cells under premature senescence by Ying Gao et al. The study investigates how PQQ, a potent antioxidant in various foods, can safeguard these cells from oxidative stress induced by hydrogen peroxide (H2O2). By examining the impact of PQQ on cell growth, metabolic activity, mitochondrial function, and the expression of senescence markers, the research aims to understand the mechanisms behind PQQ's ability to prevent premature aging and mitochondrial dysfunction. The findings suggest that PQQ enhances mitochondrial health through the SIRT1/PGC-1α signaling pathway, potentially offering new avenues for treating oxidative stress and cellular aging conditions.
Introduction
Pyrroloquinoline quinone (PQQ) is a powerful antioxidant that helps protect cells from damage. This study focuses on how PQQ protects auditory cells, specifically HEI-OC1 cells, from stress. Mitochondria are the powerhouses of our cells, and keeping them healthy is vital for overall cell function. This study explores the role of PQQ in maintaining mitochondrial health in these auditory cells.
Understanding Oxidative Stress
Oxidative stress occurs when there is an imbalance between free radicals and antioxidants in the body. Free radicals are unstable molecules that can damage cells. One common free radical is hydrogen peroxide (H2O2). Cells can get damaged when there are too many free radicals and insufficient antioxidants to neutralize them.
This damage can lead to premature aging and various health problems. When cells experience oxidative stress, they can enter premature senescence. In this state, cells stop dividing and don't function properly.
The study states, "H2O2 is widely utilized as an agent to induce premature cellular senescence in cell lines." Scientists often use hydrogen peroxide in experiments to create a model of aging cells.
In previous studies, short exposure to H2O2 caused a significant decrease in cell population and mitochondrial respiratory capacity, leading to an imbalance of mitochondrial fusion and fission.
The regulation of aging also relies on the function of reactive oxygen species (ROS) in redox signaling. Controlling oxidative stress is essential to preventing cell damage and aging.
PQQ: The Antioxidant Hero
Pyrroloquinoline quinone (PQQ) is a powerful antioxidant in foods such as kiwi, parsley, cocoa powder, and even human breast milk. Antioxidants like PQQ help neutralize harmful free radicals, protecting cells from damage. PQQ was first reported as a new coenzyme in glucose dehydrogenase in 1964. Its structure was determined by X-ray analysis in 1979.
PQQ is known for its ability to neutralize superoxide and hydroxyl radicals, which can cause mitochondrial dysfunction. The study mentions, "PQQ is especially effective in neutralizing superoxide and hydroxyl radicals, which cause mitochondrial dysfunction." This means PQQ can help protect the tiny powerhouses inside our cells, the mitochondria, from being damaged by these harmful molecules.
Previous research has shown that PQQ can protect cells from various types of damage. It has been reported to protect against glutamate-induced cell apoptosis in primary cultured hippocampal neurons and antagonize oxidative stress-induced cell damage, including chronic heart failure, ethanol-induced liver damage, and hyperoxia-induced cognitive deficits.
The Experiment
The experiment aimed to test the effects of PQQ on HEI-OC1 auditory cells exposed to oxidative stress. HEI-OC1 cells are a type of cell used in research to study the inner ear. Researchers wanted to see if PQQ could protect these cells from damage caused by oxidative stress.
To do this, they treated the cells with two different concentrations of PQQ (0.1 nM and 1.0 nM) for one day before exposing them to hydrogen peroxide (H2O2). Hydrogen peroxide created oxidative stress and induced premature senescence in the cells. The study states, "Cells were treated with PQQ for 1 day before H2O2 (100 μM) exposure."
After treating the cells with PQQ and H2O2, researchers examined various aspects of the cells' health. They looked at cell growth, metabolic activity, mitochondrial function, and the expression of certain proteins that are markers of cell aging.
They also used different assays to measure the mitochondrial membrane potential and the levels of senescence-associated β-galactosidase (SA-β-Gal) and dipeptidyl peptidase DPP4 (CD26) cell surface protein as biomarkers for cellular senescence.
The results showed that PQQ helped protect the cells from the damaging effects of oxidative stress. This suggests that PQQ could be a valuable tool in preventing and treating conditions related to oxidative stress and mitochondrial dysfunction.
Key Findings
Cell Growth and Metabolism
Cells treated with PQQ showed increased growth and metabolic activity. At 1.0 nM, PQQ significantly boosted cell growth. The study found that "The population doubling rate increased significantly compared to the control when the concentration of PQQ was 1.0 nM."
Mitochondrial Function
PQQ improved the mitochondrial respiratory capacity, helping cells produce more energy. It also promotes mitochondrial fusion and movement, which is essential for maintaining healthy cells. The research noted, "A decrease in mitochondrial potential, the promotion of mitochondrial fusion and the accelerated movement of mitochondria were all observed in PQQ-pretreated cells."
Senescence Markers
PQQ reduced the markers associated with cell aging, such as p21, p16, and p53. This indicates that PQQ helps protect cells from entering a state of premature senescence. The study reported, "While H2O2 exposure increased the expression of p21 and the activity of SA-β-Gal and CD26, the expression of p21, p16, and p53 were all alleviated by 0.1 nM PQQ pretreatment."
Mitochondrial Health and PQQ
Mitochondria are essential for energy production in cells. When they are damaged, cells can't function properly. PQQ helps protect mitochondria by enhancing their function and structure. This study found that PQQ boosts the expression of proteins like SIRT1 and PGC-1α, which are crucial for mitochondrial health.
The researchers noted, "PQQ pretreatment protects mitochondrial dynamics under H2O2 exposure in HEI-OC1 cells." The study further explains, "PQQ increased the expression of SIRT1 and PGC-1α, and decreased the acetylation of PGC-1α, suggesting enhanced mitochondrial biogenesis and function."
Implications of the Study
The findings suggest that PQQ could be beneficial in preventing age-related hearing loss by protecting auditory cells from oxidative stress. This could have broader implications for other oxidative stress and mitochondrial dysfunction conditions.
The study opens up new avenues for research into PQQ's potential as a protective agent for other types of cells. The study highlights, "Considering these findings, the protective effect of PQQ in mitochondrial biogenesis is also expected for inner ear cells."
PQQ as a Key to Cellular Health and Longevity
This study shows that PQQ has a protective effect on auditory cells exposed to oxidative stress. By improving mitochondrial function and reducing cell aging markers, PQQ helps maintain cell health. These findings highlight the importance of PQQ in supporting cellular health and preventing damage from oxidative stress.
The study concludes, "PQQ has a protective effect on the premature senescence model of HEI-OC1 auditory cells and is associated with the SIRT1/PGC-1α signaling pathway, mitochondrial structure, and mitochondrial respiratory capacity."
Meet the Author
Dr. James Pendleton
Dr. James Pendleton is a primary care physician specializing in a naturopathic approach to family medicine. He has nurtured a family practice in Seattle, directed a VIP medical center in Abu Dhabi, published several books and scientific articles, and designed innovative nutritional supplements for manufacturers worldwide.
REFERENCES
- Alkahtani, S., Alarifi, S., Alkahtane, A. A., Albasher, G., Al-Zharani, M., Alhoshani, N. M., Al-Johani, N. S., Aljarba, N. H., & Saquib Hasnain, M. (2021). Pyrroloquinoline quinone alleviates oxidative damage induced by high glucose in HepG2 cells. Saudi journal of biological sciences, 28(11), 6127–6132. https://doi.org/10.1016/j.sjbs.2021.06.063
- Gao, Y., Kamogashira, T., Fujimoto, C. et al. Pyrroloquinoline quinone (PQQ) protects mitochondrial function of HEI-OC1 cells under premature senescence. npj Aging 8 , 3 (2022). https://doi.org/10.1038/s41514-022-00083-0
- Jonscher, K. R., Chowanadisai, W., & Rucker, R. B. (2021). Pyrroloquinoline-Quinone Is More Than an Antioxidant: A Vitamin-like Accessory Factor Important in Health and Disease Prevention. Biomolecules, 11(10), 1441. https://doi.org/10.3390/biom11101441
- Lobo, V., Patil, A., Phatak, A., & Chandra, N. (2010). Free radicals, antioxidants and functional foods: Impact on human health. Pharmacognosy reviews, 4(8), 118–126. https://doi.org/10.4103/0973-7847.70902
- Meyer, J. N., Leuthner, T. C., & Luz, A. L. (2017). Mitochondrial fusion, fission, and mitochondrial toxicity. Toxicology, 391, 42–53. https://doi.org/10.1016/j.tox.2017.07.019
- Misra, H. S., Khairnar, N. P., Barik, A., Priyadarsini, K. I., Mohan, H., & Apte, S. K. (2004). Pyrroloquinoline-quinone: A reactive oxygen species scavenger in bacteria. FEBS Letters, 578(1–2), 26-30. https://doi.org/10.1016/j.febslet.2004.10.061
- Pizzino, G., Irrera, N., Cucinotta, M., Pallio, G., Mannino, F., Arcoraci, V., Squadrito, F., Altavilla, D., & Bitto, A. (2017). Oxidative Stress: Harms and Benefits for Human Health. Oxidative medicine and cellular longevity, 2017, 8416763. https://doi.org/10.1155/2017/8416763
- Schumacher, B., Pothof, J., Vijg, J., & Hoeijmakers, J. H. J. (2021). The central role of DNA damage in the ageing process. Nature, 592(7856), 695–703. https://doi.org/10.1038/s41586-021-03307-7
