2021-10-31

A new study found that sars-cov-2 virus can infect the inner ear

By yqqlm yqqlm

Visit: Alibaba cloud 11.11 shangyun Carnival activity hall 2021 tmall double 11 red envelope Jingdong double 11 “top Beijing Post” collection entrance

b427e9dc145138c - A new study found that sars-cov-2 virus can infect the inner ear

the researchers also found that, The infection pattern seen in human inner ear tissue is consistent with the symptoms seen in the study of 10 covid-19 patients who reported various ear related symptoms

the researchers used the new cell model of human inner ear developed by them and the difficult to obtain adult human inner ear tissue. The limited availability of this organization has hampered previous research on covid-19 and other viruses that can cause hearing loss

Lee Gehrke, Professor Hermann L.f. von Helmholtz of MIT Institute of medical engineering and science, said: “having a model is the first step. This work opens the way not only for dealing with sars-cov-2, but also for dealing with other viruses affecting hearing.”

konstantina Stankovic is a former associate professor at Harvard Medical School and former director of otology and neurology in Massachusetts Department of Ophthalmology and otology, She is now a professor at the bertarelli foundation and director of the Department of Otolaryngology Head and neck surgery at Stanford University School of medicine. She co led the study. Minjin Jeong, a former postdoctoral of Stankovic laboratory and now of Stanford University School of medicine, is the first author of the paper. The paper was published in Communicaitons Meddicine on October 29, 2021

before the covid-19 pandemic began, Gehrke and Stankovic began a project to develop a cell model to study human inner ear infection. Cytomegalovirus, mumps virus and hepatitis virus can cause deafness, but how they do it is not well understood

in early 2020, after the emergence of sars-cov-2 virus, researchers changed their plans. At the Massachusetts Department of Ophthalmology and otology, Stankovic began to see patients with hearing loss, tinnitus and dizziness who tested positive for covid-19. “It was very unclear whether it was causal or coincidental because hearing loss and tinnitus were so common,” she recalled

she and Gehrke decided to use the model system they were studying to study the infection of sars-cov-2. They created their cell model by taking human skin cells and transforming them into induced pluripotent stem cells. They then stimulated these cells to differentiate into several types of cells in the inner ear: hair cells, Sertoli cells, nerve fibers, and Schwann cells that isolate neurons

these cells can grow in flat two-dimensional layers or organize into three-dimensional organs. In addition, researchers can obtain difficult to obtain inner ear tissue samples from patients undergoing surgery who have diseases that lead to severe vertigo attacks or tumors that lead to hearing loss and vertigo

in human inner ear samples and stem cell-derived cell models, researchers found that some types of cells — hair cells and Schwann cells — express the proteins required for sars-cov-2 virus to enter cells. These proteins include the ACE2 receptor found on the cell surface and two enzymes called Flynn protease and transmembrane protease serine 2, which help the virus fuse with the host cell

the researchers then showed that the virus can actually infect the inner ear, especially hair cells — and to a lesser extent Schwann cells. They found that other cell types in their model were not sensitive to sars-cov-2 infection

the human hair cells studied by the researchers are vestibular hair cells, which are involved in sensing head movement and maintaining balance. Cochlear hair cells involved in hearing are more difficult to obtain or generate in cell model. However, the researchers pointed out that mouse cochlear hair cells also have proteins that allow sars-cov-2 to enter

the infection pattern found by the researchers in their tissue samples seems to be consistent with the symptoms observed in a group of 10 covid-19 patients who reported ear related symptoms after infection. Nine of these patients had tinnitus, six experienced vertigo, and all experienced mild to deep hearing loss

the damage of cochlear hair cells may lead to hearing loss, which can usually be evaluated by measuring otoacoustic emission – the sound made by sensory hair cells in response to auditory stimuli. Of the six covid-19 patients who underwent this test in this study, all had decreased or disappeared otoacoustic emissions

although this study strongly suggests that covid-19 can cause hearing and balance problems, the overall proportion of ear related problems in covid-19 patients is unclear

“initially, this is because patients diagnosed with covid are not easy to carry out routine tests. In addition, when patients have more life-threatening complications, they do not pay much attention to whether they have hearing loss or tinnitus,” Stankovic said, “We still don’t know the incidence rate, but our findings do need to strengthen the attention to hearing vestibular symptoms in people who are exposed to COVID.”

possible ways for the virus to enter the ear include the eustachian tube, which connects the nose and middle ear. Stankovic said that the virus may also escape from the nose through a small opening around the olfactory nerve. This will enable it to enter the brain space and infect the cranial nerve, including the nerve connecting the inner ear.

professor of Otolaryngology Head and neck surgery, Johns Hopkins University School of medicine, did not participate Yuri Agrawal of the study noted: “This article provides very convincing evidence that sars-cov-2 infects the inner ear and may have a causal relationship with the hearing and balance symptoms of some covid-19 infected patients. Another exciting development in our field is the observation of sars-cov-2 infection in the inner ear using two-dimensional and three-dimensional extracorporeal organs. This provides a powerful platform to study other diseases The researchers now hope to use their human cell model to test possible treatments for inner ear infections caused by sars-cov-2 and other viruses