2 "facts": 1 true and 1 false about COVID-19

During COVID-19 outbreaks, divisive debates ensue regarding the role of public health in enforcing policies to close schools. While mental health detriments to children and their families are well documented (Christie, Hope, et al. 2020), some facts surrounding the extent of children’s viral loads and infection susceptibility remain unclear.

Research in 2022 by Seery et al. suggests that “although children and youth are less severely affected by SARS-CoV-2 infection in most cases, they develop a strong and more sustained antibody immune response in comparison with adults. Importantly, the ability to mount a more vigorous antibody response is clearly expressed in the development of a higher antibody response against the Omicron variant following infections by pre-Omicron variants.” In other words, not only do children suffer milder symptoms of COVID-19 when exposed, but they also sustain a stronger and more prolonged immunological response, even against future variants after their infection.

This fact is quite interesting and may have an impact on future public policy when it comes to school closures or vaccine mandates for children. My personal experience as a mother to two young children confirms this finding of less infection in children as compared to adults. When my children and I got COVID-19, I suffered a moderate case. My son’s knee ached for 30 seconds (as opposed to ongoing severe pain in my hips) and my 2-year-old had zero symptoms. I have heard similar reports from other parents and read related findings in other articles.

The second “fact” I will discuss is the idea that the COVID-19 vaccine is increasing population infection rate and virulency. This is a common idea in some circles and perpetuated by many public figures, including Dr. Tyna, a board-certified Chiropractic and Naturopathic doctor. In one of her latest blogs, she states: “our constant boosting campaign may very well be driving these increasingly more infectious and potentially more virulent strains” (Moore 2022). However, the research does not support this broad statement for the most part, for various reasons:

1. If this were true, COVID-19 infections and death would have increased after vaccinations were initiated in 2020. In fact, the opposite is the case with a decrease in infection of 54-62% in people aged 65 and older, and a decrease in hospitalizations and death by 63.5% (Moghadas et al. 2020).

2. There is still debate about whether COVID-19 has or can mutate to become more virulent. Between increased immunity due to natural infection and vaccination, it does seem that there are fewer deaths, even if there are more infections. It seems that there is nothing conclusive that states that new variants are more virulent. In a 2022 study, Wolter, Nicole et al. stated: “Newly emerged Omicron lineages BA.4/BA.5 showed similar severity to the BA.1 lineage and continued to show reduced clinical severity compared to the Delta variant”. That is to say, the Delta variant had more severe disease outcomes than the later Omicron variants of BA.1 and BA.4/BA.5.” This supports the statement that variants are not becoming more clinically dangerous. While we don’t have all the answers yet, Dr. Tyna’s statement that the virus is becoming more virulent is not conclusively found.

3. I was going to look for research that discounted Dr. Tyna’s claim that vaccines are driving mutations. However, I was shocked to discover this is being shown in some recent research: “Our results implied that the widely extended use of COVID-19 vaccines and immune pressures in vaccinated individuals could be one of the explanations for driving the genetic mutation and evolution of S gene of SARS-CoV-2. Moreover, S protein is the major protein used as a target in COVID-19 vaccines, and the interaction between the receptor binding region (RBD) of the S gene and host receptor cells Links to an external site.could accelerate the genetic mutation of the S gene of SARS-CoV-2 virus under vaccine pressures” (Yang et al. 2022). In other words, vaccine use has driven some specific vaccine-targeted proteins in the virus to mutate faster, in countries where there was wide vaccine intake. Thus, Dr. Tyna has a point that vaccines may be causing more rapid mutations. However, it has yet to be proven that the new viruses are more virulent. This is certainly possible, but there is not enough research to confirm this.

Doing this project confirmed how difficult it is to separate fact from falsity. It does seem clear that children are better protected against COVID-19. However, I assumed Dr. Tyna was completely wrong in everything she said in the quoted statement but upon deeper research, I found there to be contradictory evidence. After doing this research, I personally think that vaccines may indeed drive more mutations, however, it does seem to have protected most of us from severe diseases. Perhaps we need to increase focus on pharmaceutical treatments in the case that COVID-19 does mutate beyond the scope of the vaccine.

This was a humbling experience and I look forward to the continuing findings on this fascinating and ever-evolving subject, and the strategies to fight COVID-19.  

REFERENCES

Christie, Hope, et al. "Examining Harmful Impacts of the COVID‐19 Pandemic and School Closures on Parents and Carers in the United Kingdom: A Rapid Review." JCPP Advances, vol. 2, no. 3, 2022, pp. n/a.  https://acamh-onlinelibrary-wiley-com.ezproxy.lib.ryerson.ca/doi/full/10.1002/jcv2.12095Links to an external site.

Seery, Vanesa, et al. “Antibody Response against SARS-CoV-2 Variants of Concern in Children Infected with Pre-Omicron Variants: An Observational Cohort Study.” EBioMedicine, vol. 83, no. 104230, 2022, p. 104230, doi:10.1016/j.ebiom.2022.104230.  https://www.sciencedirect.com/science/article/pii/S2352396422004121Links to an external site.

Moore, Tyna. “The Plan Is NOT Working so Well.” Dr. Tyna Show Podcast & Censorship-Free Blog, 30 Sept. 2022, https://drtyna.substack.com/p/the-plan-is-not-working-so-wellLinks to an external site.

Moghadas, Seyed M., et al. “The Impact of Vaccination on COVID-19 Outbreaks in the United States.” MedRxiv : The Preprint Server for Health Sciences, 2021, doi:10.1101/2020.11.27.20240051.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7709178/Links to an external site.

Wolter, Nicole et al. “Clinical severity of SARS-CoV-2 Omicron BA.4 and BA.5 lineages compared to BA.1 and Delta in South Africa.” Nature communications vol. 13,1 5860. 4 Oct. 2022, doi:10.1038/s41467-022-33614-0 https://pubmed.ncbi.nlm.nih.gov/36195617/Links to an external site.

Yang, Jing, et al. “Relatively Rapid Evolution Rates of SARS-CoV-2 Spike Gene at the Primary Stage of Massive Vaccination.” Biosafety and Health, vol. 4, no. 4, 2022, pp. 228–233, doi:10.1016/j.bsheal.2022.07.001. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9277989/Links to an external site.

Beta-galactosidase as indicator of senescent and cancer cells

Yesterday I was listening to a news segment on CBC Links to an external site.about cervical cancer screening results that currently have 6-month delays in parts of Canada due to post-pandemic backup and staff shortages. Coincidently, while researching beta-galactosidase, I discovered that this enzyme is an important biomarker for certain cancers, including ovarian cancer (Fan et al., 2021) and, most recently, has been found to be over-expressed in gastric cancer as well (Kubo et al., 2021). 

Human beta-galactosidase is highly expressed in senescent cells, which are cells that stop dividing but continue to exist and metabolize. Accumulation of senescent cells is an indicator of aging in general, and the presence of these cells is associated with a risk for many diseases including cancer, osteoarthritis, atherosclerosis (arterial plaque build-up), Alzheimer’s, diabetes, and more (Childs et al., 2017) (Chen et al., 2022). Interestingly, cellular senescence seems to be one of the body’s defenses against tumor growth, in that it’s a way for the body to stop the division of cells that have shortened telomeres and may have mutations (Campisi, 2001). Yet, secretions by senescent cells also cause disease (Childs et al., 2017) and even a small number of senescent cell secretions such as cytokines can have a significant impact on cells throughout the entire body and cause or increase disease (Burton, 2009).  And so, the presence of an accumulation of human beta-galactosidase in tissues indicates aging and the onset or development of disease.  

Early cancer detection greatly affects survival rates. Moreover, distinguishing the exact type of cancer aids in treatment decisions. Finding biomarkers that indicate early cancer growth and specify the type of cancer is key to increasing survivorship. Beta-galactosidase is shown to be present in ovarian cancer and most recently associated with gastric cancer (Kubo et al., 2021). Detection of beta-galactosidase has been historically done by a technology called X-gal but has certain disadvantages including that it can only be done in cells that are non-living and the staining takes a long time and is difficult to visualize. However, a new technology called Cellular Senescence Detection Kit - SPiDER-βGal is more sensitive, easier to see, and can be done on live cells (in vivo) (Cellular Senescence Detection Kit - SPiDER-βGal, n.d.).

The image shows beta-galactosidase cells illuminated with the application of SPiDER-βGal technology. Source: (Cellular Senescence Detection Kit - SPiDER-βGal, n.d.).

Research has shown that beta-galactosidase fluorescent illumination is a reliable indicator for gastric cancer, liver, and other cancers. B-galactosidase is found in higher concentrations in tumor tissues compared to healthy cells. The presence of beta-galactosidase can be seen visually, with a stronger fluorescence indicating higher concentrations.  Furthermore, the detection is fast and can be seen only 10 minutes after application. This technology could thus be used during surgery, to help surgeons see cancer cells during surgery, namely fluorescence-guided surgery (Ogawa et al., 2021). Also, it can shine for hours, is non-toxic, and will illuminate even at low concentrations. Detecting and removing even small amounts of cancer cells can greatly decrease reoccurrences or metastasis. 

I became curious to learn exactly how the probe lights up beta-galactosidase and it took hours of research to find some semblance of an explanation. I finally came upon J. Zhang et al., the researchers who originally developed the technology and published their findings, in 2017. The probe is a substrate for Beta-galactosidase and ‘turns on’ in a solution with H2O. It can detect even a small concentration of 0.1 nM and has a very high bonding affinity. The probe can distinguish between endogenous Beta-galactosidase cells and non-endogenous. It has a hemicyanine structure (meaning dyes with two aromatic groups) with a D-galactose residue using a glycosidic bond and s fluorescent intensity at 703nm (J. Zhang et al., 2017). 

I will admit I am still not satisfied with this information and want to really understand how this probe lights up the specific substrate groups. Here is an image that I partially understand. I can see that Gal-Pro is the probe. It meets with Beta-galactosidase. The top sugar (chair-shaped) comes off and binds to beta-galactosidase. I have many remaining questions, such as why it bonds and how it illuminates. I am sure I am limited in my understanding as my organic chemistry knowledge is not comprehensive. Perhaps someone can comment and explain what happens on a substrate level and what causes the fluorescence. 

Image from Qiu et al., 2020.

In summary, beta-galactosidase is present in high concentrations in senescent cells and is an indicator of ovarian and gastric cancer. SPiDER-βGal probe is a powerful new technology that can be used for fluorescence-guided surgery to find and remove cancer cells. It can also be used as a fast biomarker in vivo for the presence of gastric and ovarian cancer, even in small concentrations.

REFERENCES

Kubo, H., Murayama, Y., Ogawa, S., Matsumoto, T., Yubakami, M., Ohashi, T., Kubota, T., Okamoto, K., Kamiya, M., Urano, Y., & Otsuji, E. (2021). β-Galactosidase is a target enzyme for detecting peritoneal metastasis of gastric cancer. Scientific Reports, 11(1), 10664. https://doi.org/10.1038/s41598-021-88982-2Links to an external site.

Fan, F., Zhang, L., Zhou, X., Mu, F., & Shi, G. (2021). A sensitive fluorescent probe for β-galactosidase activity detection and application in ovarian tumor imaging. Journal of Materials Chemistry. B, Materials for Biology and Medicine, 9(1), 170–175. https://doi.org/10.1039/d0tb02269aLinks to an external site.

Childs, B. G., Gluscevic, M., Baker, D. J., Laberge, R.-M., Marquess, D., Dananberg, J., & van Deursen, J. M. (2017). Senescent cells: an merging target for diseases of ageing. Nature Reviews. Drug Discovery, 16(10), 718–735. https://doi.org/10.1038/nrd.2017.116Links to an external site.

Chen, Y.-H., Zhang, X., Ko, K.-Y., Hsueh, M.-F., & Kraus, V. B. (2022). CBX4 regulates replicative senescence of WI-38 fibroblasts. Oxidative Medicine and Cellular Longevity, 2022, 5503575. https://doi.org/10.1155/2022/5503575

Childs, B. G., Gluscevic, M., Baker, D. J., Laberge, R.-M., Marquess, D., Dananberg, J., & van Deursen, J. M. (2017). Senescent cells: an emerging target for diseases of ageing. Nature Reviews. Drug Discovery, 16(10), 718–735. https://doi.org/10.1038/nrd.2017.116Links to an external site.

Campisi, J. (2001). Cellular senescence as a tumor-suppressor mechanism. Trends in Cell Biology, 11(11), S27-31. https://doi.org/10.1016/s0962-8924(01)02151-1

Burton, D. G. A. (2009). Cellular senescence, ageing and disease. Age (Dordrecht, Netherlands), 31(1), 1–9. https://doi.org/10.1007/s11357-008-9075-y

Cellular Senescence Detection Kit - SPiDER-βGal. (n.d.). Dojindo.eu.com. Retrieved December 8, 2022, from https://www.dojindo.eu.com/store/p/895-Cellular-Senescence-Detection-Kit-SPiDER-Gal.aspx

Ogawa, S., Kubo, H., Murayama, Y., Kubota, T., Yubakami, M., Matsumoto, T., Yamamoto, Y., Morimura, R., Ikoma, H., Okamoto, K., Kamiya, M., Urano, Y., & Otsuji, E. (2021). Rapid fluorescence imaging of human hepatocellular carcinoma using the β-galactosidase-activatable fluorescence probe SPiDER-βGal. Scientific Reports, 11(1), 17946. https://doi.org/10.1038/s41598-021-97073-1

Zhang, J., Li, C., Dutta, C., Fang, M., Zhang, S., Tiwari, A., Werner, T., Luo, F.-T., & Liu, H. (2017). A novel near-infrared fluorescent probe for sensitive detection of β-galactosidase in living cells. Analytica Chimica Acta, 968, 97–104. https://doi.org/10.1016/j.aca.2017.02.039

Qiu, W., Li, X., Shi, D., Li, X., Gao, Y., Li, J., Mao, F., Guo, Y., & Li, J. (2020). A rapid-response near-infrared fluorescent probe with a large Stokes shift for senescence-associated β-galactosidase activity detection and imaging of senescent cells. Dyes and Pigments: An International Journal, 182(108657), 108657. https://doi.org/10.1016/j.dyepig.2020.108657

Where does the fat go when you lose weight? Out your mouth? Really??

This is my response to a biochemistry assignment, in which our professor asked us to read and respond to the following article: https://www.medicalnewstoday.com/articles/287046

This is wild because just two days ago I bought a Lumen, which is a device that you breathe into throughout the day that claims to track your respiration exchange rate (RER), which is your CO2 to O2, exhalation/inhalation ratio. Lumen claims their device can train your metabolism by providing personalized advice on exercise and diet in response to your RER. This week’s assignment is a perfect opportunity to dig a little deeper into the relationship between RER and weight loss and see if this was a smart purchase.

Image from https://www.lumen.me/metabolic-flexibilityLinks to an external site.

The specific statement I would like to focus on from the article “Majority of weight loss occurs ‘via breathing’” is:

The results suggest that the lungs are the main excretory organ for weight loss, with the H20 produced by oxidation departing the body in urine, feces, breath and other bodily fluids.

This statement is derived from the works of Brown and Meerman, as published in their peer-reviewed article in the Britsh Medical Journal. The authors deduce that the equation for the oxidation of a single triglyceride is:

C55H104O6+78O2→55CO2+52H2O+energy

Triglyceride breakdown equation from Meerman and Brown, 2014.

Using stoichiometry, Brown and Meerman explain that 10 kg of fat requires 29 kg of oxygen which results in 11kg of H20 and 28 kg of CO2. Building on the 1949 research of Lifson et. al., which found that the synthesis of carbonic acid powers the exchange between oxygen in H20 and gaseous CO2, Meerman and Brown traced oxygen’s path and found that for every 4 O2's exhaled, 2 bind with hydrogens to form water. Therefore, according to Brown and Meerman, exhalation is indeed the main exit pathway for oxygens broken up by triglycerides, with the remainder exiting as H20, in a 2:1 ratio (Meerman & Brown, 2014).

These findings are reinforced by another peer-reviewed article that is essentially a lab directive for students to calculate oxygen and food intake against carbon dioxide output after exercise (Merritt, 2022). I found an interesting peer-reviewed paper on bats that found that the exhalation ratio in bats reflects the food type (protein, carbohydrates, fat) their muscles are currently burning (Youngsteadt, 2011). There are many articles that measure metabolic adaptation by way of carbon dioxide exhalation monitoring, such as the 2018 study by Moll et al., which found CO2 exhalation to be a reliable way to observe aerobic and anaerobic pathways in athletes, in addition to blood lactate concentration testing.

After my research, I am convinced that carbon dioxide exhalation is the exit pathway for catabolized triglycerides. However, I would like to see more articles that directly test this hypothesis.

Many questions remain. Can the Lumen breath analyzer show reliable readings that accurately reflect what the metabolism is burning? While metabolic flexibility (the ability to shift between fat burning to carbohydrate burning, for example) is affirmed by research (Goodpaster & Sparks, 2017), the Lumen itself is not proven to be a trustworthy measurement device (Hall, 2021).

Luckily, the Lumen has a money-back guarantee. I will test it out for myself and let you know my anecdotal experience!

REFERENCES

Meerman, R., & Brown, A. J. (2014, January 1). When somebody loses weight, where does the fat go? The BMJ. Retrieved November 22, 2022, from https://www.bmj.com/content/349/bmj.g7257Links to an external site.

Lifson, Nathan, et al. "The fate of utilized molecular oxygen and the source of the oxygen of respiratory carbon dioxide, studied with the aid of heavy oxygen." J Biol Chem 180.2 (1949): 803-11. https://web.archive.org/web/20171023163139id_/http://www.jbc.org/content/180/2/803.full.pdfLinks to an external site.

Merritt, Edward K. "Why is it so Hard to Lose Fat? because it has to Get Out through Your Nose! an Exercise Physiology Laboratory on Oxygen Consumption, Metabolism, and Weight Loss." Advances in Physiology Education, vol. 45, no. 3, 2021, pp. 599-606. https://go.exlibris.link/4sb7LsvF Links to an external site. 

Youngsteadt, Elsa. "Bats Gorge during Exercise."American Scientist, vol. 99, no. 2, 2011, pp. 124. https://go.exlibris.link/W60561rX Links to an external site. 

Moll, Kevin, et al. "Comparison of Metabolic Adaptations between Endurance‐ and sprint‐trained Athletes After an Exhaustive Exercise in Two Different Calf Muscles using a multi‐slice 31P‐MR Spectroscopic Sequence."NMR in Biomedicine, vol. 31, no. 4, 2018, pp. n/a. https://pubmed.ncbi.nlm.nih.gov/29393546/ Links to an external site. 

Goodpaster, B. H., & Sparks, L. M. (2017, May 2). Metabolic Flexibility in Health and Disease. Cell Metabolism. Retrieved November 23, 2022, from https://www.cell.com/cell-metabolism/abstract/S1550-4131(17)30220-6Links to an external site.

Hall, H. (2021, July 27). Lumen’s Information Is Not So Illuminating. Science-Based Medicine. Retrieved November 23, 2022, from https://sciencebasedmedicine.org/lumens-information-is-not-so-illuminating/ Links to an external site. 

Phosphoglucose Isomerase or The Future of Early Cancer Detection

I chose phosphoglucose isomerase (GPI) because I like its bilateral symmetry, which reminds me of the shape of the human heart. GPI is the second enzyme in the glycolysis pathway. It is an isomerase, which means no atoms are added or removed. Rather, it changes the shape of glucose 6-phosphate to fructose 6-phosphate and vice versa, based on the cellular needs at the time. The small yellow part in David Goodsell’s image represents fructose-6-phosphate, thus in his drawing, it has just changed a glucose-6-phosphate into a fructose-6-phosphate ("PDB101: Molecule of the Month: Glycolytic Enzymes"). As described in this week’s lecture, this is done by shifting a 6-membered ring into a 5-membered ring. In addition to Goodsell's image, I also included an image from Wikipedia of a rabbit GPI as it has a nice depiction of the alpha-helixes. 

Image 1: Drawing by David Goodsell from Molecule of the Month: https://pdb101.rcsb.org/motm/50 Links to an external site. 

Image 2: Wikipedia.” Glucose-6-phosphate Isomerase - Wikipedia, en.wikipedia.org/wiki/Glucose-6-phosphate_isomerase 

What is fascinating about GPI (also called glucose-6-phosphate isomerase, phosphoglucoisomerase and phospohexose isomerase) is that scientists have recently discovered that this enzyme has numerous other functions, in addition to its activity in the cytosol during glycolysis. Outside the cell, GPI functions as a neurotrophic factor, promoting the growth of motor and sensory nerve cells. In this role, GPI is also sometimes referred to as a neuroleukin. Other important functions of this versatile enzyme include its role as a lymphokine that promotes antibody secretion and as AMF (autocrine motility factor), which gathers at tumor sites and functions as a cytokine (Ahmad et al. 2022).

Although I chose this enzyme randomly, or simply because I liked its shape, an eerie coincidence emerged. Just a few days ago, during a routine check-up, I asked my doctor if there was a blood test that could detect cancer in its early stages. My mother has stage 4 cancer, and it’s tragic that this recurrence of cancer, which she has had three times now, wasn’t caught earlier this time, and had already significantly metastasized. It would save countless lives if there existed a simple blood test to detect early-stage cancer, that people could include as part of routine check-ups. My doctor informed me that such a test does not yet exist, but that scientists are working on it.

How does this relate to GPI, the second enzyme in glycolysis? When GPI is found outside the cell as an AMF, it has been secreted by a tumor and is found in higher concentrations at that site. AMF is structurally identical to GPI but named differently due to its distinct location, function, origin, and role. AMF contributes to metastasis by enabling the movement of tumor cells by decreasing the tumor’s adhesion and fostering its motility, migration, survival, and proliferation (Funasaka et al., 2007).

What is very exciting in cancer research, is that scientists have recently created a biosensor that detects excess phosphoglucose isomerase (or AMF) in human plasma using an enzyme inhibitor that selectively interacts with AMF. The technology can identify excess AMF in 10 minutes. Developing cancer biomarker equipment that is fast, manageable in size, and readily available to the public is revolutionary for the early detection of cancer. And the use of inhibitors as identifiers will be applicable in the early detection of other diseases as well (Ahmad, Lama, et al. 2022). While I initially imagined this post to be an in-depth exploration of one enzyme in one step of glycolysis, I never imagined it would unpack what seems to be a revolutionary technology that may serve as a significant factor in the detection of early cancer.

REFERENCES

“PDB101: Molecule of the Month: Glycolytic Enzymes.” RCSB: PDB-101, pdb101.rcsb.org/motm/50. Accessed 18 Nov. 2022.

“Glucose-6-phosphate Isomerase - Wikipedia.” Glucose-6-phosphate Isomerase - Wikipedia, en.wikipedia.org/wiki/Glucose-6-phosphate_isomerase. Accessed 18 Nov. 2022.

Funasaka, Tatsuyoshi, and Avraham Raz. “The role of autocrine motility factor in tumor and tumor microenvironment.” Cancer metastasis reviews vol. 26,3-4 (2007): 725-35. doi:10.1007/s10555-007-9086-7

Ahmad, Lama, et al. “Electrochemical Detection of the Human Cancer Biomarker ‘Autocrine Motility Factor-Phosphoglucose Isomerase’ Based on a Biosensor Formed with a Monosaccharidic Inhibitor.” Sensors and Actuators. B, Chemical, vol. 299, 2019, p. 126933., https://doi.org/10.1016/j.snb.2019.126933. Accessed 19 Nov. 2022.