Reactive oxygen species (ros): signaling and oxidative stress

Reactive oxygen species (ROS) are chemically reactive chemical species containing oxygen. Examples include peroxides, superoxide, hydroxyl radical, and singlet oxygen.[1]

In a biological context, ROS are formed as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis.[2] However, during times of environmental stress (e.g., UV or heat exposure), ROS levels can increase dramatically.[2] This may result in significant damage to cell structures. Cumulatively, this is known as oxidative stress. ROS are also generated by exogenous sources such as ionizing radiation.[3]

Due to the dual role of ROS, both prooxidant and antioxidant-based anticancer agents have been developed. However, modulation of ROS signaling alone seems not to be an ideal approach due to adaptation of cancer cells to ROS stress, redundant pathways for supporting cancer growth and toxicity from ROS-generating anticancer drugs. Combinations of ROS-generating drugs with pharmaceuticals that can break the redox adaptation could be a better strategy for enhancing cancer cell cytotoxicity.[29]

James Watson[47] and others[48] have proposed that lack of intracellular ROS due to a lack of physical exercise may contribute to the malignant progression of cancer, because spikes of ROS are needed to correctly fold proteins in the endoplasmatic reticulum and low ROS levels may thus aspecifically hamper the formation of tumor suppressor proteins.[48] Since physical exercise induces temporary spikes of ROS, this may explain why physical exercise is beneficial for cancer patient prognosis.[49] Moreover, high inducers of ROS such as 2-deoxy-D-glucose and carbohydrate-based inducers of cellular stress induce cancer cell death more potently because they exploit cancer cell high avidity for sugars.[50]

Effects of ROS on cell metabolism are well documented in a variety of species. These include not only roles in apoptosis (programmed cell death) but also positive effects such as the induction of host defence[9][10]genes and mobilization of ion transport systems.[citation needed] This implicates them in control of cellular function. In particular, platelets involved in wound repair and blood homeostasis release ROS to recruit additional platelets to sites of injury. These also provide a link to the adaptive immune system via the recruitment of leukocytes.[citation needed]

Reactive oxygen species are implicated in cellular activity to a variety of inflammatory responses including cardiovascular disease. They may also be involved in hearing impairment via cochlear damage induced by elevated sound levels, in ototoxicity of drugs such as cisplatin, and in congenital deafness in both animals and humans.[citation needed] ROS are also implicated in mediation of apoptosis or programmed cell death and ischaemic injury. Specific examples include stroke and heart attack.[citation needed]

In general, harmful effects of reactive oxygen species on the cell are most often:[11]

damage of DNA or RNA
oxidations of polyunsaturated fatty acids in lipids (lipid peroxidation)
oxidations of amino acids in proteins
oxidative deactivation of specific enzymes by oxidation of co-factors
Singlet oxygen is highly reactive, especially with organic compounds that contain double bonds. The resulting damage caused by singlet oxygen reduces the photosynthetic efficiency of chloroplasts. In plants exposed to excess light, the increased production of singlet oxygen can result in cell death.[8] Various substances such as carotenoids, tocopherols and plastoquinones contained in chloroplasts quench singlet oxygen and protect against its toxic effects. In addition to direct toxicity, singlet oxygen acts a signaling molecule.[8] Oxidized products of β-carotene arising from the presence of singlet oxygen act as second messengers that can either protect against singlet oxygen induced toxicity or initiate programmed cell death. Levels of jasmonate play a key role in the decision between cell acclimation or cell death in response to elevated levels of this reactive oxygen species.[8]

[yuguotompkins]

Could you please site the graps and figures

[ramezsaied]

i honestly wish i had someone as enthusiastic as you as my professor, thank you for sharing

[melinaoliveira]

I am just watched your video right now and I understood everything! Thank you! Congratulations!

[Vice]

Has anyone here looked into The Perth Group's theory of Oxidative Stress and Cellular Redox hypothesis regarding HIV/AIDS?

[OIOnaut]

Thank You for this piece of valuable info.

I am trying to figure out what is the role of the microbiota in mothers birth channel regarding the baby's future ROS signaling capability. I understand that we inherit only half of our ROS signaling capability from the egg's mitochondria and the other half from carbon redox molecules made by microbiota living on the birth channel surfaces. Many with c-section history have autoimmune problems. Correlation, cause or effect?

I am a semiconductor engineer with deep biohacking interest in natural solar radiation, earth magnetism, structured deuterium depleated aka metabolic celluar water and circadian changes regarding to our mitochondrial health.

[ebrahimalqadasi]

man you are great .. i watched your immunology videos and am glad that i found your channel .. i hope you never stop and will be waiting for more of your great work 👍

[MOAB-UT]

Brilliant, thank you for sharing. So does exercising benefit us by increasing Mitochondrial output/ROS and Apoptosis so that they are in balance? My understanding is that too little ROS is bad as is too much.

[dragonslayer]

Have you ever had a glass of kangen water? It's water that has been run over a live electrical current, specifically a series of electrically charged, platinum coated titanium plates. The water provides antioxidants at a level that would take barrels and barrels of blueberries to match.

[thelastcipher]

Is the video description from wikipedia? I want to look for the sources. Thanks!

[samarpitadash]

sir how UCP2 protein is acting for ROS?

[yourfriendlyneighborhoodin]

You look at this complex system and pretend it's an accident.

😂

[tammyhall]

Please don’t say the Lord’s name in vain. We are here to learn not for theatrics.

[admirer]

Used "G-- damn" in the video to express how upset you were? Disappointing.