Categories
Neuroscience

Mouse Study: Follicle-Stimulating Hormone Is a Key Instigator of Alzheimer’s Disease

A study published in Nature reports that Follicle-Stimulating Hormone (FSH) may be a key instigator of Alzheimer’s disease (AD). Treatment including gene therapy and anti-FSH antibodies reversed and prevented AD-related pathologies in mice.

Background

Alzheimer’s disease (AD) is the 7th leading annual cause of death in the United States and is typically caused by an abnormal buildup of two proteins: amyloid and tau. Amyloid proteins help with neuron growth and repair but can destroy nerve cells later in life due to abnormal buildups referred to as plaques. Tau is intended to stabilize neurons by providing them with a  neurofibrillary structure. When unregulated, tau proteins can dysfunctionally aggregate into neurofibrillary tangles (NFTs), causing AD.

Elevated follicle-stimulating hormone (FSH) levels are often associated with menopause and, when regulated, the hormone’s intended purpose in the human body is to stimulate egg and sperm development. Both low and high levels of FSH are associated with infertility and sexual defects.

Scientists have long suspected that menopause plays a role in the pathogenesis of AD. During menopause, females have elevated levels of FSH, which—among other hormones—can lead to bone decay, weight gain, tiredness, and cognitive defects like those observed in AD patients. Women have a three-times higher rate of disease progression.

Method & Results

To determine if FSH is linked to the development of AD, researchers from Emory University and Icahn School of Medicine conducted an experiment in which they manipulated FSH levels in mice and then examined cognitive function and plaque formation.

In mice injected with extra FSH for three months, researchers already observed amyloid plaques and and tau NFTs, as well as inflammation and destruction of neurons—all symptoms of AD. Specifically, the damage, plaques, and NFTs occurred largely in hippocampal and cortical neurons. Further, these mice showed impaired spatial memory as demonstrated by comparatively poor performance in a water maze test. These changes were observed in both male and female mice.

The researchers then administered an antibody drug that lowers FSH levels. After treatment, they identified that the same AD symptoms identified in the FSH-supplemented mice had nearly disappeared. Their anti-FSH antibody (FSH-Ab) inhibited amyloid plaque and NFT formation while also reversing cognitive decline. As FSH-Ab inhibits all functions of FSH, the mice would also experience increased bone mass, decreased body fat, and increased energy expenditure.

The researchers believe excess FSH causes an increase in the expression of a gene that regulates an enzyme called arginine endopeptidase. This enzyme ultimately keeps amyloid and tau proteins in check, but once overproduced, clumping and tangling can begin. Experimentation revealed that either the deletion of this gene via gene therapy or FSH-Ab treatment successfully reduced amyloid plaques and tau NFTs and improved water maze performance.

While increased FSH levels in menopausal women is implied in the pathogenesis of AD, the researchers tested how male mice would respond to FSH-Ab. They found that the antibody “at the very least” prevented amyloid accumulation in the male mice.

Discussion

The researchers concluded that extremely high FSH levels can impact protein regulation pathways, eventually leading to AD-related pathologies in mice. Also, antibody therapy targeting FSH can reverse and prevent formation of amyloid plaques and NFTs. Mice had recovered performance in cognitive tests following FSH-Ab treatment.

These findings have serious implications if the findings translate to humans. FSH concentrations could be used as an assay in patients to determine pathology and treatment. Antibody and gene therapies that proved to reverse and prevent AD symptoms in mice could also be used in humans with FSH-induced AD.

References
  • Abbott, A. (2022, March 9). Could drugs prevent Alzheimer’s? These trials aim to find out. Nature. https://www.nature.com/articles/d41586-022-00651-0
  • Murphy, S. L., et al. (2021, December). https://www.cdc.gov/nchs/data/databriefs/db427.pdf. National Center for Health Statistics. https://www.cdc.gov/nchs/data/databriefs/db427.pdf
  • Orlowski, M., & Sarao, M. S. (2021, May 9). Physiology, follicle stimulating hormone. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK535442/#NBK535442_pubdet
  • Xiong, J., Kang, S., et al. (2022, March 2). FSH blockade improves cognition in mice with Alzheimer’s disease. Nature. https://www.nature.com/articles/s41586-022-04463-0
Categories
Immunotherapy Public Health

How Bacteriophages Could Save Humanity from Antibiotic Resistance

“Thanks to penicillin… he will come home!” pronounced a Life magazine advertisement published in 1944. At this time, penicillin, the first true antibiotic drug, had just been discovered and made commercially available.

Antibiotics are drugs that prevent or treat bacterial infections. Before the advent of penicillin, the leading causes for death were bacterial infections resulting in pneumonia, tuberculosis, diarrhea, and enteritis, causing one third of all deaths in the United States. Since then, the idea of deaths by bacterial infection have largely faded into the past—until the evolution of antibiotic-resistant bacteria has now threatened this status quo.

In antibiotic or antimicrobial resistance, antibiotics are no longer effective against bacteria that have evolved to survive it, particularly using beta-lactamase enzymes. This resistance is further accelerated by excessive, unnecessary use of antibiotics, mainly in industrial livestock production and over-prescription. This increased use contributes to the evolutionary pressure on microbes to develop resistance to antibiotics.

Alexander Fleming, who discovered penicillin, was receiving the Nobel Prize in medicine and physiology when he ominously predicted antibiotic resistance: “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them.” Fleming himself was hesitant of widespread antibiotic use, recognizing its resistant capabilities from the year they were released. In 2019, the CDC reported more than 2.8 million antibiotic-resistant infections in the US.

Antibiotics have very specific mechanisms of action to target bacteria. For example, penicillin binds to an enzyme on the bacteria and removes it, which breaks an important barrier in the cell. If one certain bacteria has a mutated enzyme, the antibiotic will be rendered ineffective, and that mutation will become prevalent in that bacterial species.

A key difference between bacteria and most other organisms is their ability to transmit genes to nearby bacteria in a process called horizontal gene transfer. This is why bacterial resistance has quickly become an epidemic as it spreads quickly and efficiently. Unfortunately, it would take almost a decade to modify the antibiotics necessary to combat these “superbug” bacteria.

Bacteriophages, meaning “bacteria eaters,” are viruses that only infect bacteria. Most are lytic, meaning that when infecting a host, they inject their genes into the host, utilize the host to rapidly replicate, and destroy the cell walls by bursting through, essentially creating a “phage-producing factory” from a bacteria. A small number are lysogenic, which means they coexist with bacteria.

Consequently, bacteriophages have provoked the interest of researchers as a potential replacement for traditional antibiotics, which are obtained from fungi. While there are a little over 100 known traditional antibiotic drugs to fight the near-infinite supply of bacteria in the world, estimates show that there exist about 10 phages for each bacterium. This indicates that there may be many more potentially therapeutic bacteriophages than traditional antibiotics. Bacteriophages are the most abundant “organism” in the biosphere, either living harmoniously with bacteria in the lysogenic cycle or destroying about 40% of the ocean’s bacteria every day, amounting to 10²³ phage infections in only one second.

Though, phages have drawbacks as potential antibiotic therapies. For one, they are extremely specific. While a single traditional antibiotic can target a multitude of bacteria, bacteriophages target one bacteria. A working solution for this is the use of “phage cocktails,” which combine multiple natural and synthetic bacteriophages to more effectively treat patients.

Also, phages are not entirely shielded from bacterial resistance. Bacteria can fight back with certain immune responses, specifically CRISPR Cas  systems. However, unlike antibiotics, phages are continually adapting and responding to such defensive systems. This continual mutation of phages poses a risk for FDA approval, but some researchers are working on machine learning  systems to predict these changes.

Still, bacteriophages show promise as an alternative therapy to traditional antibiotics. Scientists hope that phages will become an alternative defense against bacteria that could help ease antimicrobial resistance.

References
Categories
Pharmacology

Clascoterone, First Novel Acne Therapy in 38 Years, Treats Acne By Blocking Facial Androgen Receptors

In 1982, the FDA approved isotretinoin (Accutane), a Vitamin A derivative, for use in patients with acne. No new methods of acne medication had been approved from 1982 until the approval of topical clascoterone in August 2020, almost 40 years later.

Topical clascoterone is a cream that is applied directly to the skin of areas affected by acne. Clascoterone is an antiandrogen, which is a class of drug that blocks androgen receptors. The drug is the first antiandrogen to be approved by the FDA for acne medication, earning it the title of first-in-class medication. Androgens, which are male sex hormones present in males and lower levels in females, play an important role in the pathogenesis of acne.

During puberty, both males and females have increased levels of androgens like testosterone or dihydrotestosterone (DHT). Higher levels of testosterone can cause increased production of sebum, an oily substance secreted by sebaceous glands under the skin. Excessive amounts of sebum in a skin pore can cause a blockage (known as a comedo, blackhead, or whitehead) that may become infected.

Clascoterone was shown in vitro to have higher affinity for androgen receptors than DHT. This blockage of local androgen receptors by clascoterone was then shown by clinical trials to reduce the acne-causing effects of androgens.

The Investigator’s Global Assessment Scale (IGA) is a scale of acne severity that goes from 0 (clear) up to 4 (severe). Two clinical trials found that at least 18% of patients achieved a drop of at least 2 points on the IGA scale (resulting in a score of 0 or 1) at 12 weeks into treatment with topical clascoterone. One trial showed that patients, on average, saw a 39% decrease in total lesion count after 12 weeks of treatment.

The FDA listed the most common side effects of topical clascoterone as reddening, itching, and scaling or dryness of treated skin. The FDA-approved brand of topical clascoterone is Winlevi.

References
  • Piszczatoski, C. (2021, October 2). Topical Clascoterone: The First Novel Agent for Acne Vulgaris in 40 Years. https://doi.org/10.1016/j.clinthera.2021.08.007
  • U.S. Food and Drug Administration. (2020, September 3). Drug trial snapshot: Winlevi. https://www.fda.gov/drugs/drug-approvals-and-databases/drug-trial-snapshot-winlevi
Categories
Neuroscience

Transparent Zebrafish Study Reveals How Sleep Repairs Damaged Neuronal DNA

Using transparent zebrafish, Israeli researchers were able to confirm neuronal DNA repair as a function of sleep, also identifying a protein that triggers both DNA repair and sleep.

Background

The functions of sleep, though widely researched, have largely remained a mystery. It is known that sleep influences cognition, benefitting learning and memory, but proposed physiological functions have had little strong evidence. Proposed functions of sleep include removing toxic byproducts in the brain caused by wakefulness, replenishing energy and supplies for cells, and remediating neural damage and cellular stress.

Prior research showed that wakefulness and neuronal activity causes DNA double-strand breaks. These lesions are accumulated during wakefulness, contributing to homeostatic sleep drive (the pressure to sleep that builds up as time awake increases). Sleep has been demonstrated to decrease this DNA damage.

Researchers from Israel’s Bar-Ilan University and Tel Aviv University used zebrafish to study neuronal DNA repair as a potential novel function of sleep. The zebrafish is a tiny freshwater fish that has been widely used as a model organism due to their 70% genetic homology (similarity) to humans. Among other parallel physiologies, zebrafish exhibit a diurnal sleep cycle with states closely resembling mammalian slow-wave sleep (SWS) and rapid eye movement (REM) sleep. A mutated type of zebrafish is transparent, enabling researchers to observe the previously unobservable.

Confocal microscopy image showing the developing face of a 6 day old zebrafish larva. / Oscar Ruiz and George Eisenhoffer, University of Texas MD Anderson Cancer Center

By inducing neuronal DNA damage in zebrafish, they were able to determine its relation to sleep as well as causal proteins.

Results

First, the researchers confirmed a significant positive correlation between levels of neuronal DNA damage and total sleep time (R = 0.76). During wakefulness, zebrafish larvae were treated with pentylenetetrazol, which stimulated their neuronal activity. Consequently, the larvae had increased neuronal DNA damage and a 5-fold increase in total sleep time.

Because neuronal DNA damage is not only caused by cell activity, the researchers then exposed the larvae to UV radiation, which damaged their DNA without increasing their neuronal activity. Their subsequent increased sleep further confirmed that DNA damage was the cause.

By testing the rates at which genes involved in the DNA damage response (DDR) were expressed during sleep, they found that the RAD52 and Ku80 proteins were responsible for repairing double-strand breaks during sleep.

Further analysis uncovered that the PARP1 protein, a DNA damage detector that organizes the DDR, was immediately recruited and activated upon neuronal DNA damage.

When the researchers provoked greater expression of PARP1, total sleep time and depth increased—demonstrating that the protein is what connects the DNA damage response to homeostatic sleep drive. PARP1 was also shown to promote sleep regardless of damage.

Discussion

The study confirms in multiple experiments that neuronal DNA repair is a function of sleep regulated by the PARP1 enzyme and carried out by the DNA repair proteins RAD52 and Ku80.

Triggering neuronal DNA damage via cellular excitation and UV light both caused the expected result of increased sleep, with PARP1 as the protein responsible for detecting the damage, provoking a repair response, and causing increased sleep drive.

The study authors noted their intrigue that FDA-approved PARP1 inhibitors used as antitumor agents all caused fatigue as the prominent side effect, suggesting that inhibiting PARP1 masks its sleep-promoting signals. The use of PARP1 inhibitors was also found to cause increased DNA damage. These results, separate from their study, align with their findings regarding the functions of PARP1 as observed in zebrafish.

References
  • Frank, M. G. (2006, August 1). The mystery of sleep function: Current perspectives and future directions. De Gruyter. https://doi.org/10.1515/revneuro.2006.17.4.375
  • Yourgenome. (2021, July 21). Why use the zebrafish in research? https://www.yourgenome.org/facts/why-use-the-zebrafish-in-research
  • Zada, D., et al. (2021, December 16). Parp1 promotes sleep, which enhances DNA repair in neurons. Molecular Cell. https://doi.org/10.1016/j.molcel.2021.10.026
Categories
Neuroscience

New Stem Cell Mechanism Behind Down Syndrome Discovered, Paves Way for Treatment

A team of researchers from MIT’s Alana Down Syndrome Center published results in Cell Stem Cell that pointed to a mechanistic link between Down syndrome (DS) and genome-wide transcriptional disruption. The team, led by Hiruy Meharena, revealed that senescence (the state when cells stop dividing) may play an important role in the progression of down syndrome and could lead to novel therapeutic approaches for treating individuals with DS.

Down syndrome, also known as trisomy 21 (T21), is a congenital disorder that is caused by the triplication of  the 21st chromosome. Previous studies have linked the cognitive deficits of the disorder to a lack of dysfunctional neural progenitor cells (NPCs). These are the stem cells that differentiate into glial and neuronal cells which make up the central nervous system. Neurogenesis, the process in which new neurons are formed in the brain, was found to be significantly reduced in the brains of mice with DS because the lack of NPCs ultimately led to a decrease in cortical matter.

Another study linked T21 to transcriptional disruption in human-derived induced pluripotent stem cells (or iPSCs). His research team found that the disruption to those cells was also consistent with other papers that examined related aneuploidies. Nonetheless, while both studies did reveal a connection between T21 and the cells, they did not delve into the factors that caused this relationship.

As a result, Meharena’s study explores a potential mechanism that may explain how this transcriptional disruption may take place. His team examined T21’s effect on DS-related iPSCs and NPCs at the genetic, epigenetic and mRNA levels. Their finding revealed that although the iPSC were not significantly affected, the NPCs that were derived from these iPSCs revealed significant chromosomal introversion and disrupted lamina-associated domains. This made it so that the squished chromosomes would have increased genetic interactions within itself but decreased interactions with the other chromosomes. Additionally, they found decreased NPC’s chromatin accessibility to the A-compartment, which is associated with transcriptional downregulation, and increased accessibility to the B-compartment, which is associated with transcriptional upregulation.

What was notable was that these changes of differentially expressed genes of NPCs shared many qualities with cells that became senescent via oxidative stress conditions. Furthermore, senolytic pharmaceutical treatments of dasatinib and quercetin was found to ease some of the transcriptional disruption and deficiencies that arose from T21 affected NPCs. The use of these drugs not only improved gene accessibility and transcription but also helped with cellular migration and proliferation.

Although this treatment is not practical due to the neutropenic (neutrophil-decreasing) side effects of dasatinib, it stills elucidates a previously unknown avenue for research into potential treatments to be conducted. With Down syndrome being one the most common intellectual disabilities, having a stronger understanding of the mechanisms behind its progression may provide an opportunity to restore or prevent some of the dysfunctions of the disease. Although this research is only a small piece to the larger puzzle that is DS, it still provides a step to better understanding the condition, hopefully one day assisting individuals with the disorder and their families.

References
Categories
Cardiology Immunotherapy

CAR T Cells Produced by mRNA Injection Reduce Cardiac Fibrosis, Restore Function to Heart

Researchers at the University of Pennsylvania’s Perelman School of Medicine have published a method to treat cardiac fibrosis using an mRNA injection that enables an individual’s own CAR T cells to fight the disease.

Background

Cardiac fibrosis is a medical condition caused by many different types of heart disease that can lead to scarring and stiffening in the muscle wall of the heart. Normally, cells in the heart called cardiac fibroblasts help to develop the heart and maintain its homeostasis (that is, it helps the heart stay in a stable condition). However, in a patient with cardiac fibrosis, these cells no longer perform their normal function. Following a cardiac injury, fibrosis can progress from scarring to complete heart failure.

T cells are a type of white blood cell that play a key role in immune response, killing cells that they recognize to be infected with viruses, cancers, or certain other pathogens. Chimeric antigen receptor (CAR) T cells are T cells that have been engineered to recognize specific proteins as harmful. This enables them to target and kill cells that have proteins from diseases that they otherwise would not recognize as harmful.

Innovation

The Penn researchers developed a CAR T-cell therapy that works by engineering T cells to recognize and kill cells that express (create) the fibroblast activation protein (FAP), a protein key to the pathology of cardiac fibrosis. Killing FAP-expressing cells consequently treats cardiac fibrosis.

By encoding a messenger RNA (mRNA) strand that results in the creation of CAR T cells that target FAP, the researchers had the idea to deliver them to a patient’s cells through an injection containing the mRNA within a lipid nanoparticle.

Lipid nanoparticles (LNP) are a relatively new technology discovered in the 1990s. To deliver an mRNA strand into cells to provoke a protein-expressing response, the mRNA is inserted into a sphere made of lipids that is injected into a patient. This then allows cells to uptake the LNP through endocytosis (bringing material into the cell). The mRNA then exits the LNP, causing the cell to read the mRNA instructions to create the desired protein.

09908-feature1-nanoparticle.jpg
Structure of the LNP. / Genevant Sciences via ACS.org

Without the LNP, mRNA would be unable to enter cells. mRNA vaccines for COVID-19 are a prominent use of this technology, as the mRNA that gives cells instructions to create the spike protein is protected and brought into cells by LNP.

Results

In rodents with cardiac fibrosis, the Penn researchers revealed that their mRNA injection successfully resulted in the creation of FAP-targeting CAR T cells. Observing the hearts of rodents before and after treatment showed notable improvements in cardiac function. This means that as the CAR T cells killed cells that expressed FAP, fibrosis was reduced.

Video of rodent echocardiograph recorded two weeks after treatment with CAR T-cell therapy that was given after an injury that caused cardiac fibrosis. / Rurik et al., 2022

In rodents with injuries causing cardiac fibrosis, the CAR T-cell treatment halved the percentage of fibrosis in the ventricles.

Discussion

The implications of this new treatment are of great significance. Reduction of fibrosis and restoration of cardiac function in rodents with cardiac fibrosis reveals a promising new form of treatment for human patients with the potentially fatal disease.

According to the CDC, about 659,000 people in the United States die from heart disease each year, accounting for 1 in every 4 deaths–all costing the country hundreds of billions of dollars each year. Thus, biotechnological innovations in treatment of cardiac disease can have a great impact.

Earlier CAR T-cell therapies have required a patient’s T cells to be extracted from blood, sent to a lab, engineered to find and kill certain targets, then returned intravenously to the patient. This is an extremely time-consuming and cost-prohibitive process, potentially costing patients hundreds of thousands of dollars.

The innovation of using mRNA injections to create CAR T cells within a patient’s own body instead of a lab may greatly reduce the time and financial burdens associated with CAR T-cell therapies. Rather than extracting, modifying, and replacing T cells from each patient, mRNA shots that provoke the creation of CAR T cells can be mass-produced and given to any patient.

The scope of this innovation reaches far beyond cardiac fibrosis, as it can potentially be applied to CAR T-cell therapies for cancer and other diseases.

References
Categories
COVID-19 Immunology

As Antibodies Wane in Quantity and Efficacy, T Cells Remain Effective Against Omicron

Background

As the Omicron variant of COVID-19 becomes increasingly dominant among skyrocketing cases, including in vaccinated individuals, concerns of the variant’s immune escape abilities have grown.

Vaccines provoke important responses in the immune system to prevent disease, including creation of T cells and antibodies specific to the pathogen they introduce. In the case of mRNA vaccines for COVID-19, genetic code (mRNA) for the spike protein enters our cells, causing them to manufacture spike proteins. Our immune system then recognizes these proteins as foreign to our bodies, promptly destroying them while creating T cells and antibodies that can work against them in the future.

Antibodies and T cells play different roles in the event of an infection. Antibodies work by creating sites that bind to certain parts of a pathogen. As they pertain to mRNA COVID-19 vaccines, the antibodies will bind strongly to the spike protein. Since the spike protein is what enables SARS-CoV-2 to enter cells, binding antibodies to them will prevent infection.

On the other hand, T cells help fight infection by injecting poison into cells that are already infected, killing both the cell and the pathogen. mRNA vaccines help T cells recognize when a cell is infected with SARS-CoV-2. This means that antibodies are more useful for preventing infection via neutralization while T cells are better at stopping an infection that has already infected some cells.

These figures model T cell and antibody responses to viral infection. In an average SARS-CoV-2 infection, T cells have a greater response than antibodies, and this response effectively decreases viral load. In a severe infection, antibodies are far more prominent than T cells, and this response is ineffective at decreasing the viral load. T cells are more effective at managing instead of preventing an infection, so they would be more useful than antibodies in an already severe infection. (Sette, Crotty 2021)

Much of the focus surrounding COVID-19 vaccines and their efficacy has related to antibody quantity and binding affinity to the changed spike proteins of new variants in order to prevent infection instead of the role of T cells in managing infection. Researchers sought to quantify both antibody and T cell counts and efficacy in unvaccinated, twice vaccinated, and three-times vaccinated patients.

Results

A preprint study from Erasmus University Medical Center in the Netherlands detected high antibody levels against the original SARS-CoV-2 spike protein following receipt of the Pfizer or Moderna mRNA vaccines. Lower (but still significant) antibody levels were detected from the Johnson & Johnson viral vector vaccine. However, antibody levels from the mRNA vaccines decreased significantly within 6 months, while those from the viral vector vaccine did not. Though, even if neutralizing antibody levels remained high, researchers from Beijing’s Peking University found that Omicron escapes most SARS-CoV-2 neutralizing antibodies.

Studies from the Icahn School of Medicine at Mount Sinai in New York supported earlier reports that convalescent (unvaccinated, previously infected) and twice-vaccinated individuals had nonexistent protection against symptomatic infection from the Omicron variant. Boosted (three-times vaccinated) individuals had about 75% protection against symptomatic disease from Omicron, though it is unknown how long this protection will last.

Importantly, the Erasmus study found that unlike neutralizing antibodies, SARS-CoV-2-specific T cells were still detected in the blood 6 months after mRNA and viral vector vaccination as well as natural infection.

In contrast to findings that most neutralizing antibodies are largely ineffective against Omicron, data from Pfizer and BioNTech showed that 80% of spike-specific T cells in vaccinated individuals retained function. The Erasmus researchers corroborate this, finding that vaccinated individuals retain T cell immunity to the Omicron variant.

Discussion

Results from multiple studies now support a consensus that naturally infected and twice-vaccinated individuals have nonexistent protection against symptomatic infection due to depleted and ineffective neutralizing antibodies.

However, both populations can reattain significant protection against symptomatic infection by receiving initial vaccinations or a booster–though it is still unknown how long this protection will last.

These data indicate that convalescent individuals greatly benefit from vaccination, an observation that is of significant public health importance.

Carreño et al., 2021

Even though it has become significantly more difficult to prevent symptomatic infection due to the waning quantity and efficacy of neutralizing antibodies in convalescent and vaccinated individuals, T cells have been shown to remain active and are expected to still help prevent severe infection.

This is supported by new data that has shown that SARS-CoV-2-specific T cells remain present in the long-term and are still mostly effective against the Omicron variant in convalescent and vaccinated individuals.

Well-preserved T cell immunity to Omicron is likely to contribute to protection from severe COVID-19, supporting early clinical observations from South Africa.

Keeton et al., 2021
References
  • BioNTech. “Update – Omicron Variant (B.1.1.529).” BioNTech Investors & Media, 8 Dec. 2021, https://investors.biontech.de/static-files/47b4131a-0545-4a0b-a353-49b3a1d01789.
  • Cao, Yunlong, et al. “Omicron Escapes the Majority of Existing SARS-COV-2 Neutralizing Antibodies.” Nature, 23 Dec. 2021, https://doi.org/10.1038/d41586-021-03796-6.
  • Carreño, Juan Manuel, et al. “Activity of Convalescent and Vaccine Serum against SARS-COV-2 Omicron.” Nature, 31 Dec. 2021, https://doi.org/10.1038/d41586-021-03846-z.
  • Geurts van Kessel, Corine H., et al. “Divergent Sars Cov-2 Omicron-Specific T- and B-Cell Responses in COVID-19 Vaccine Recipients.” MedRxiv, 29 Dec. 2021, https://doi.org/10.1101/2021.12.27.21268416.
  • Keeton, Roanne, et al. “SARS-COV-2 Spike T Cell Responses Induced upon Vaccination or Infection Remain Robust against Omicron.” MedRxiv, 28 Dec. 2021, https://doi.org/10.1101/2021.12.26.21268380.
  • Sette, Alessandro, and Shane Crotty. “Adaptive Immunity to SARS-COV-2 and COVID-19.” Cell, 18 Feb. 2021, https://doi.org/10.1016/j.cell.2021.01.007.
  • Wu, Katherine J. “T Cells Might Be Our Bodies’ Best Shot against Omicron.” The Atlantic, 14 Dec. 2021, https://www.theatlantic.com/science/archive/2021/12/t-cells-omicron-vaccine-immunity/620995/.
Categories
COVID-19

Researchers Reveal Portable COVID Testing Method, Gives Results Within One Second

Researchers from the University of Florida, along with collaborators from the National Chiao Tung University, recently created the world’s fastest COVID detection test to date using a new method with antibody-infused test strips and a small circuit board.

Since the beginning of the COVID-19 pandemic, RT-PCR tests, commonly referred to as PCR, have been regarded as the gold standard for COVID-19 testing.

Reverse Transcription Polymerase Chain Reaction (RT-PCR) works by first converting RNA into DNA, followed by copying small segments of this DNA over and over, primarily using temperature to denature and bind DNA, along with “primers” to make new copies. The process takes about two hours and uses expensive machinery. Such amplification of DNA makes it easy for machines to detect the small amounts of viral particles present in infected patient samples, but difficult to apply to large populations during a pandemic.

One of the defining features of the coronavirus is the spike proteins, which enable the virus to penetrate host cells due to their geometry and location. Rather than having to convert RNA to DNA, copy the DNA, and read a signal as is done with RT-PCR tests, a new study described a system which uses the spike protein-antibody bond and circuitry for detection.

Antibodies are Y-shaped proteins our immune system produces to fight and prevent future infection. They work by creating sites to which infectious particles bind, effectively blocking those particles from infecting cells. These sites can include binding locations for viruses such as SARS-CoV-2, which researchers have found to be quite useful for detection.


As our need for fast, cheap, and portable detection grows, researchers have been searching for new methods. The researchers from the University of Florida ingeniously combined knowledge of antibodies and circuitry to detect presence of COVID in one second.

First, they modeled commercially available glucose testing strips commonly used for testing blood sugar levels in diabetic patients. If you were to dissect a glucose test strip, you would find several electrodes, coated and made of different materials.

Most commonly, glucose test strips are coated with an enzyme that reacts with glucose to steal its available electrons. These electrons are then transported to the electrode which can detect and quantify their presence, indicating how much glucose was in the blood sample.

In the study, researchers worked to transform the electrodes using different biological and chemical materials. One of the electrodes was plated with gold then “biofunctionalized” with coronavirus antibodies.  An electrode in the middle was connected to an electronic component called a metal-oxide-semiconductor field-effect transistor (MOSFET), which is used to control and amplify electrical signals.

When spike proteins from a sample interact with the surface, the antibody-antigen complex will spring up and down, causing an electrical signal to be sent to the gate of the MOSFET. The device’s circuit board can then quickly convert and read the signal. 

The MOSFET is especially important as it can convert electrical activity from the interaction of a very small amount of coronavirus with the antibodies into a very large signal, similar to how RT-PCR tests amplify the small amount of genetic material into a much larger and easier-to-detect sample.

The accuracy and acute sensitivity of this method are a direct result of combining electrical and biological tools of detection. Not only does this allow for the detection of extremely low quantities of virus particles, but it can be accomplished in merely 1 second. Furthermore, the device is inexpensive and portable, paving the way for fast, economical, and highly sensitive at-home diagnostic kits.

Notably, Minghan Xian, first author of the study, remarked that by simply altering the type of antibody used, this detection kit could be reapplied to a multitude of other infectious diseases. The electronic components can also be reused with new electrodes.

References
Categories
COVID-19 Public Health

Recovered Patients of Severe COVID-19 Infection 233% More Likely To Die Within Year Than Negative Counterparts

Research published by University of Florida scientists in Frontiers in Medicine reported that patients (aged 18-65) who recovered from severe COVID-19 infection were 233% more likely to die within 12 months than COVID-19-negative counterparts.

Methodology

The study analyzed 13,638 patients in the University of Florida Health system over a 12-month period, including positive (mild, severe) and negative cases. A severe case was defined as one requiring hospitalization within 30 days of a positive COVID-19 test. The 12-month risk of mortality was adjusted for age, sex, race, and comorbidities–meaning these factors did not affect the data.

Results

Survival curve showing probability of survival over time following mild, severe, and lack of COVID-19 illness. / Mainous 2021

Patients aged 18 to 65 who recovered from an initial episode of severe COVID-19 had a 233% increased incidence of mortality in a 12-month period compared to negative counterparts. Recovered patients aged over 65 also had increased mortality compared to negative counterparts, but to a lesser extent.

The difference in 12-month mortality between COVID-negative and mild COVID patients was not statistically significant.

Only 20% of the deaths in the 12-month period were attributed to cardiovascular or respiratory conditions.

Discussion

These results show that those who recover from severe COVID-19 infections are much more likely to die within 12 months of recovery compared to those with mild or no infection. This reveals that the increased risk of death from COVID-19 is not limited to the initial episode of infection, indicating that the biological and physiological insult from severe infection is significant. This is further demonstrated by the unexpectedly low portion of deaths caused by cardiovascular or respiratory conditions.

Arch G. Mainous III, Ph.D., first author of the study and University of Florida College of Medicine faculty member, said in a statement to the University of Florida Health Newsroom that “patients may feel that if they are hospitalized and recover from COVID-19 then they have beaten COVID-19. Unfortunately, having a substantially increased [risk] of death in the next year after recovery from a severe episode of COVID-19 shows that this is not the case. Preventing severe COVID-19 should be our primary focus.”

The study mentions that nearly all hospitalizations and severe infections are preventable. Pfizer and Moderna’s COVID-19 vaccines prevent severe infection in more than 95% of cases.

Mainous hopes that the data, which he described as devastating, will “make everyone rethink the impact of COVID-19.”

References
Categories
COVID-19 Pharmacology

Combining a Protein Found in Milk with Benadryl Reduces SARS-CoV-2 Replication in Lung Cells by 99%

Researchers looking for prevention and treatment strategies for COVID-19 that are not impacted by SARS-CoV-2 mutations published findings in Pathogens that showed that a combination of diphenhydramine (the active ingredient antihistamine in Benadryl) with lactoferrin (an immunologically active protein found in human and cow milk) reduced SARS-CoV-2 replication by 99% in human cells.

Background

The key to the researchers’ findings related to proteins called the sigma receptors. These receptor proteins are located in the endoplasmic reticulum (ER), an organelle responsible for protein folding and transportation. Sigma receptors have multiple functions, including regulation of the ER stress response.

The ER stress response occurs when the ER is overwhelmed with unfolded or misfolded proteins. This triggers the unfolded protein response (UPR), which seeks to return the cell to a normal state by increasing protein folding, autophagy (destruction of damaged proteins), and in the case of prolonged UPR, apoptosis (cell suicide).

ER stress usually occurs when the ER is overwhelmed with unfolded or misfolded proteins. Cells mitigate ER stress by provoking the unfolded protein response (UPR), which includes increased protein folding, autophagy (destruction of damaged proteins) and, in prolonged cases, apoptosis (cell suicide).

When the UPR causes autophagy, it does so by forming sites near the ER called autophagosomes. Coronaviruses (CoV) have been found to bind directly to the sigma-2 receptor to cause ER stress, enabling them to hijack autophagosomes for use as virus replication sites.

Implication

Researchers found that by binding a drug molecule to the sigma-2 receptor, SARS-CoV-2 would no longer be able to bind to it to cause ER stress (and ultimately virus replication). This is made even more effective by also binding to and activating the function of the sigma-1 receptor.

Results

The team identified a ligand called AZ66 as being able to bind to both sigma-1 and sigma-2 receptors. In experiments with human lung cells infected with SARS-CoV-2, AZ66 completely blocked virus production. However, the safety of AZ66 is unknown, as the drug candidate has not been tested in clinical trials.

Molecular docking model of human sigma-2 receptor (orange) bound to AZ66 (yellow).

Searching for common compounds with proven records of safety, the researchers analyzed electronic medical records to identify diphenhydramine (DPH), the active ingredient antihistamine in Benadryl, as being associated with higher survival rates for COVID-19 patients. This is due to DPH having effects on the sigma-1 receptor. DPH was found to reduce replication of SARS-CoV-2 in the infected human lung cells by about 30%.

Lactoferrin is an antimicrobial and immunostimulatory iron-sequestering protein found in human and cow milk that was brought to a researcher’s attention by the Global Virus Network’s COVID-19 task force due to its antiviral effects on SARS-CoV-2. When tested, it was also found to reduce virus replication by about 30%. The milk protein has a proven safety record as a supplement widely used to treat stomach ulcers.

When a diphenhydramine/lactoferrin combination was tested in human and monkey epithelial lung cells, they found that a synergistic effect occurred, reducing virus replication by 99%.

Commentary

The study’s first author, David A. Ostrov, Ph.D. of the University of Florida, hailed diphenhydramine and lactoferrin as “effective, economical,” and unlike AZ66, “[having] a long history of safety.” The combination could be used to prevent infection as well as decrease recovery time from COVID-19.

While the researchers await potential interest from pharmaceutical companies, Ostrov told the University of Florida Health Newsroom that he cautions against self-medicating with diphenhydramine or lactoferrin as a COVID-19 prevention or treatment. He said that any off-label use of medication should follow a consultation with a physician. Further, commercially available lactoferrin used for treatment of stomach ulcers is not exactly the same as the lactoferrin used in the study.


Lactovid™ is a combination of diphenhydramine and lactoferrin

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Warning against off-label self-medication

This article does not offer medical advice. University of Florida researcher, David A. Ostrov, Ph.D., said that any off-label use of medication should follow a consultation with a physician. Off-label use is when a medication is used for anything other than its approved purpose.

This article is based on the following sources

– Bennett, D. (2020, December 3). Existing antihistamine drugs show effectiveness against COVID-19 virus in cell testing. University of Florida Health Newsroom. https://ufhealth.org/news/2020/existing-antihistamine-drugs-show-effectiveness-against-covid-19-virus-cell-testing
– Bennett, D. (2021, November 22). Two common compounds show effectiveness against COVID-19 virus in early testing. University of Florida Health Newsroom. https://ufhealth.org/news/2021/two-common-compounds-show-effectiveness-against-covid-19-virus-early-testing
– Ostrov, D. A., Bluhm, A. P., Li, D., Norris, M. H., et al. (2021, November 20). Highly specific sigma receptor ligands exhibit anti-viral properties in SARS-Cov-2 infected cells. Pathogens. https://doi.org/10.3390/pathogens10111514
– Vela, J. M. (2020). Repurposing sigma-1 receptor ligands for COVID-19 therapy? Frontiers in Pharmacology. https://doi.org/10.3389/fphar.2020.582310