Omicron subvariant BA.2 – which was dominant worldwide early this year, including in Hong Kong – replicates more swiftly than other strains and causes faster programmed cell death in human brains, a new study has found.
Scientists from the University of Hong Kong and Chinese University of Hong Kong exposed brain cells developed in laboratories to Omicron subvariants, as well as the original coronavirus strain from the Wuhan outbreak and the Delta strain for comparison, to assess their neurological impact.
The study findings were published in a letter in peer-reviewed science journal Nature on November 20.
It is not the first study into neurological problems – such as disturbed brain function, inflammation and dementia – caused by Covid-19.
But the Hong Kong researchers aimed to find out if, and how, Omicron subvariants behaved differently in terms of impact on brain cells compared to earlier strains.
To do this, the scientists developed cells in the laboratory that mimicked human brain cells and challenged them with the Omicron variants BA.1 and BA.2, as well as the earlier Delta variant and the original, or wild-type, strain detected in Wuhan at the start of the pandemic.
They found that BA.2 replicated much faster than other strains in experiments on in vitro forebrain and midbrain cells. BA.2 was also found to induce a lower level of interferon – a protein released by the human body as a defence mechanism against viral infections – than other strains.
While all variants induced programmed cell death upon infection of brain cells, BA.2 “triggered a substantially higher magnitude” of programmed cell death compared with other strains in the experiments, the scientists said.
They also included two new Omicron variants – BA.4.1 and BA.5.2 – to test their ability to replicate in human brain cells. They found that BA.5.2, a close relative of BA.5 which has been dominant in Europe in recent months, replicated much faster than BA.4.1 in human brain cells.
Both BA.4.1 and BA.5.2 are offshoots of BA.2.
BA.5 and BA.4 have overtaken BA.2 in recent months, but BQ.1 – a descendant of BA.5 – is now the dominant strain in the United States and some European countries.
The scientists described the findings as “alarming” and called for further research on the neurological impact of Omicron variants.
“While most patients survived the infection, post-Covid-19 sequelae, including neurological manifestations, are common,” they wrote.
“The increased efficiency of BA.2 to replicate and cause apoptosis [programmed cell death] in the brain organoids is alarming, indicating that the long-term consequence of BA.2 infection in the central nervous system (CNS) should be closely monitored.”
Previous studies have suggested that neurological complications can cause long-Covid symptoms such as loss of taste and smell, impaired concentration, fatigue, pain and sleep disorders.
News
Current Heart Health Guidelines Are Failing To Catch a Deadly Genetic Killer
New research reveals that standard screening misses most people with a common inherited cholesterol disorder. A Mayo Clinic study reports that current genetic screening guidelines overlook most people who have familial hypercholesterolemia, an inherited disorder that [...]
Scientists Identify the Evolutionary “Purpose” of Consciousness
Summary: Researchers at Ruhr University Bochum explore why consciousness evolved and why different species developed it in distinct ways. By comparing humans with birds, they show that complex awareness may arise through different neural architectures yet [...]
Novel mRNA therapy curbs antibiotic-resistant infections in preclinical lung models
Researchers at the Icahn School of Medicine at Mount Sinai and collaborators have reported early success with a novel mRNA-based therapy designed to combat antibiotic-resistant bacteria. The findings, published in Nature Biotechnology, show that in [...]
New skin-permeable polymer delivers insulin without needles
A breakthrough zwitterionic polymer slips through the skin’s toughest barriers, carrying insulin deep into tissue and normalizing blood sugar, offering patients a painless alternative to daily injections. A recent study published in the journal Nature examines [...]
Multifunctional Nanogels: A Breakthrough in Antibacterial Strategies
Antibiotic resistance is a growing concern - from human health to crop survival. A new study successfully uses nanogels to target and almost entirely inhibit the bacteria P. Aeruginosa. Recently published in Angewandte Chemie, the study [...]
Nanoflowers rejuvenate old and damaged human cells by replacing their mitochondria
Biomedical researchers at Texas A&M University may have discovered a way to stop or even reverse the decline of cellular energy production—a finding that could have revolutionary effects across medicine. Dr. Akhilesh K. Gaharwar [...]
The Stunning New Push to Protect the Invisible 99% of Life
Scientists worldwide have joined forces to build the first-ever roadmap for conserving Earth’s vast invisible majority—microbes. Their new IUCN Specialist Group reframes conservation by elevating microbial life to the same urgency as plants and [...]
Scientists Find a Way to Help the Brain Clear Alzheimer’s Plaques Naturally
Scientists have discovered that the brain may have a built-in way to fight Alzheimer’s. By activating a protein called Sox9, researchers were able to switch on star-shaped brain cells known as astrocytes and turn them into [...]
Vision can be rebooted in adults with amblyopia, study suggests
Temporarily anesthetizing the retina briefly reverts the activity of the visual system to that observed in early development and enables growth of responses to the amblyopic eye, new research shows. In the common vision [...]
Ultrasound-activated Nanoparticles Kill Liver Cancer and Activate Immune System
A new ultrasound-guided nanotherapy wipes out liver tumors while training the immune system to keep them from coming back. The study, published in Nano Today, introduces a biodegradable nanoparticle system that combines sonodynamic therapy and cell [...]
Magnetic nanoparticles that successfully navigate complex blood vessels may be ready for clinical trials
Every year, 12 million people worldwide suffer a stroke; many die or are permanently impaired. Currently, drugs are administered to dissolve the thrombus that blocks the blood vessel. These drugs spread throughout the entire [...]
Reviving Exhausted T Cells Sparks Powerful Cancer Tumor Elimination
Scientists have discovered how tumors secretly drain the energy from T cells—the immune system’s main cancer fighters—and how blocking that process can bring them back to life. The team found that cancer cells use [...]
Very low LDL-cholesterol correlates to fewer heart problems after stroke
Brigham and Women's Hospital's TIMI Study Group reports that in patients with prior ischemic stroke, very low achieved LDL-cholesterol correlated with fewer major adverse cardiovascular events and fewer recurrent strokes, without an apparent increase [...]
“Great Unified Microscope” Reveals Hidden Micro and Nano Worlds Inside Living Cells
University of Tokyo researchers have created a powerful new microscope that captures both forward- and back-scattered light at once, letting scientists see everything from large cell structures to tiny nanoscale particles in a single shot. Researchers [...]
Breakthrough Alzheimer’s Drug Has a Hidden Problem
Researchers in Japan found that although the Alzheimer’s drug lecanemab successfully removes amyloid plaques from the brain, it does not restore the brain’s waste-clearing system within the first few months of treatment. The study suggests that [...]
Concerning New Research Reveals Colon Cancer Is Skyrocketing in Adults Under 50
Colorectal cancer is striking younger adults at alarming rates, driven by lifestyle and genetic factors. Colorectal cancer (CRC) develops when abnormal cells grow uncontrollably in the colon or rectum, forming tumors that can eventually [...]
