These days the whole world has been extremely concerned about a novel, but very contagious coronavirus, called the severe acute respiratory coronavirus 2 (SARS-CoV-2), first discovered in Wuhan, Hubei – the central province of China. SARS-CoV-2 causes coronavirus disease 2019 (COVID-19), manifesting with flu-like symptoms which may finally develop into a serious pneumonia.

Coronavirus SARS-CoV-2 belongs to the big group of corona-viruses, typically surrounded with a special envelop built of proteins the virus utilizes to anchor to the surface of the cells it wants to infect (the name corona-virus is related to the crown-like spikes on its surface, called “S” proteins) (1).

Interestingly, viruses cannot even be called living organisms as they don’t have the means to survive on their own. Viruses rely solely on their human cell hosts to multiply, and use their molecular machinery to survive.

Genetic material carrying the information about all the genes the virus needs to propagate and build up other viral particles is composed of ribonucleic acid (RNA), which is different than the commonly known deoxyribonucleic acid (DNA), which encodes genetic information in our cells.

It is well known that different coronaviruses reside in animals, such as bats or pangolins, causing no harm to these species. However, viruses rely on finding a host enabling their easy multiplication and fast spread. When in contact with humans, viruses can adapt to infecting human cells and start jumping from one person to another (2). This scenario seems very likely with SARS-CoV-2 as well as the previous SARS-CoV-1 and MERS-CoV, which led to outbreaks and severe human respiratory system infections in 2003 and 2012, respectively.

 

The novel coronavirus is an RNA virus. It uses a spike protein to attach to and infect live cells.

 

Fast spreading of the novel (SARS-CoV-2) coronavirus throughout many regions of the globe forced the World Health Organization to announce a pandemic. As a result, not only have our everyday, personal and professional activities drastically changed, but also scientific progress in the next few weeks is a big question mark for the whole research community. Incredibly enough, before the COVID-19 pandemic became an unwanted fact, scientific laboratories all over the world had wasted no time producing a number of papers being a milestone in our understanding of SARS-CoV-2 biology and planning on its neutralization strategy. The latter is strongly dependent on an efficient anti-SARS-CoV-2 vaccine and drugs.

These recent reports on SARS-CoV-2 mostly enabled us to understand its cell entry mechanism. SARS-CoV-2 uses similar mechanisms  of infection as the previously known SARS-CoV-1, dependent on two proteins called TMPRSS2 (Transmembrane Serine Protease 2) and ACE2 (Angiotensin Converting Enzyme 2, also involved in the blood pressure rising) (3). SARS-CoV-2, similarly to SARS-CoV-1 affects mostly the respiratory system. This is because many cell types in the lung, including pneumocytes (main respiratory tract cells) and macrophages (immune cells) have high levels of ACE2 (4,5).

 

Young woman is measuring blood sugar level and using mobile phone. Credit: AzmanL
If you have diabetes, get your blood sugar under control. Credit: AzmanL.

 

But why should that be relevant to you, if you are diabetic? First of all, your immune system may not work as efficiently as in healthy people – so you may be more susceptible to infections (6). If you’re diabetic, you need to take all the precautions not to expose yourself to the novel virus. The most important thing is controlling your glucose levels.

High blood glucose causes inflammation which may lead to desensitization of your constantly alerted immune system, which means your immune system’s reaction might not be as strong if it encounters the virus. Secondly, reports published by Chinese clinicians and researchers (7-10) seem to indicate that SARS-CoV-2 infection is particularly dangerous when accompanying hypertension or a combination of both diabetes (either type 1 or 2) and hypertension.

According to this research, the most serious COVID-19 cases in Wuhan, China were observed in the group of patients who had been taking blood pressure drugs, including ACE2 type-I receptor blockers (ARBs). Taking  the ACE2 inhibitors by diabetic patients with high blood pressure seems to result in an increased production of endogenous ACE2 (11,12). This may possibly be explained by the need to keep a balance in the amount of ACE2 present on the surface of our cells.

If we think about the mechanism coronaviruses use to enter our cells, particularly the pneumocytes, where ACE2 is the main entry site, increasing ACE2 levels may enable the novel SARS-CoV-2 to infect cells more easily and to cause more severe disease. This is yet to be fully confirmed and it is worth emphasizing that the results of these studies are questioned by the most current reports showing the opposite – protection of patients with increased ACE2 production. However, if you are hypertensive and/or diabetic and you are not sure which types of drugs you were prescribed, it is always good to talk to your doctor and make sure everything is under control.

Make a good plan on your own on what you need to do to protect yourself against COVID-19 in the upcoming weeks. First and foremost, control your blood glucose to enhance your immune system sensitivity to SARS-CoV-2 with proper diet, sleep and exercise. Follow these 5 tips to help you boost your immune system naturally to reduce your risk of becoming infected. Since the novel coronavirus can survive on different surfaces and in the air for long hours, remember to wear a mask and gloves in public spaces – this is how I approach our current enemy as well!

 

References:

  1. Kandeel M, Ibrahim A, Fayez M, Al-Nazawi M.From SARS and MERS CoVs to SARS-CoV-2: Moving toward more biased codon usage in viral structural and nonstructural genes J Med Virol. 2020. doi: 10.1002/jmv.25754. [Epub ahead of print].
  2. https://www.cdc.gov/coronavirus/types.html
  3. Hoffmann M, Kleine-Weber H, Schroeder S, Krüger N, Herrler T, Erichsen S, Schiergens TS, Herrler G, Wu NH, Nitsche A, Müller MA, Drosten C, Pöhlmann S. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell. 2020. pii: S0092-8674(20)30229-4. doi:10.1016/j.cell.2020.02.052. [Epub ahead of print] PubMed PMID: 32142651.
  4. Shieh WJ, Hsiao CH, Paddock CD, Guarner J, Goldsmith CS, Tatti K, Packard M, Mueller L, Wu MZ, Rollin P, Su IJ, Zaki SR. Immunohistochemical, in situ hybridization, and ultrastructural localization of SARS-associated coronavirus in lung of a fatal case of severe acute respiratory syndrome in Taiwan. Hum Pathol. 2005 ;36(3):303-9.
  5. Zhou, P., Yang, X.L., Wang, X.G., Hu, B., Zhang, L., Zhang, W., Si, H.R., Zhu, Y., Li, B., Huang, C.L., et al.. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature 2020. https://doi.org/10.1038/s41586-020-2012-7.
  6. Berbudi A, Rahmadika N, Cahyadi AI, Ruslami RType 2 Diabetes and its Impact on the Immune System. Curr Diabetes Rev. 2019 Oct 23. doi: 10.2174/1573399815666191024085838. [Epub ahead of print]
  7. Yang X, Yu Y, Xu J, et al. Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-centered, retrospective, observational study. Lancet Respir Med 2020; published online Feb 24. https://doi.org/10.1016/S2213-2600(20)30079-5.
  8. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med 2020; published online Feb 28. DOI:10.1056/NEJMoa2002032.
  9. Zhang JJ, Dong X, Cao YY, et al. Clinical characteristics of 140 patients infected by SARS-CoV-2 in Wuhan, China. Allergy 2020; published online Feb 19. DOI:10.1111/all.14238.
  10. Wan Y, Shang J, Graham R, Baric RS, Li F. Receptor recognition by novel coronavirus from Wuhan: An analysis based on decade-long structural studies of SARS. J Virology 2020; published online Jan 29. DOI:10.1128/ JVI.00127-20.
  11. Fang L, Karakiulakis G, Roth M. Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? Lancet Respir Med. 2020. pii: S2213-2600(20)30116-8. doi: 10.1016/S2213-2600(20)30116-8. [Epub ahead of print]
  12. Li XC, Zhang J, Zhuo JL. The vasoprotectiveaxes of the renin-angiotensin system: physiological relevance and therapeutic implications in cardiovascular, hypertensive and kidney diseases. Pharmacol Res 2017; 125: 21–38.