Chinese scientists have discovered a new strategy for early control of novel coronavirus infections

2022-05-18 0 By

In the face of the novel Coronavirus virus, the traditional coronavirus response measures are somewhat inadequate.Are there simple, practical ways to combat the current COVID-19 pandemic?After in-depth research, The team of Prof. Bo Huang and Chuan Qin of the Chinese Academy of Medical Sciences found that targeting alveolar macrophages is an effective strategy for early control of novel coronavirus infection, and identified two clinically common old drugs in a MOUSE model of COVID-19.The relevant research results were published online in the international academic journal “Signal transduction and Targeted Therapy”.”This study can not only provide a safe and effective treatment for COVID-19, but also a bold attempt to ‘reapply old drugs’ and provide a new idea for the screening of novel coronavirus treatment drugs.”On April 7, Huang Bo stressed in an interview with science and Technology Daily.Alveoli, like balloons, are the basic structural units of the lungs.The inner surface of the alveoli, called the pulmonary surfactant layer, is made up of a thin layer of lipid and protein that keeps the alveoli stretched.At the same time, this lipid membrane can isolate the outside world from the inside of the body, and blood drug molecules, including antibodies, do not have the ability to cross the alveolar surface active layer.But how does the novel Coronavirus, which first invades the alveoli, break through the “isolation” of the body’s layers of defense?In response, huang bo explained that although the alveolar surface active layer isolates external and internal, but our immune systems have a full-time phagocytes, known as macrophages, the macrophages through the alveolar surface active layer, can eat inhaled air contained in particles and microorganisms, thereby maintaining alveolar clean.”Therefore, once the novel coronavirus enters the alveoli, the alveolar macrophages use the membrane on their surface to wrap the virus particles into the cytoplasm, and this virus-coated vesicle is called the endocytosome.”According to Huang, the endocytosome can deliver the virus particles to the lysosome, the intracytoplasmic waste disposal station, where the virus is broken down into amino acids, nucleotides and so on, which can be reused by cells.However, the Novel Coronavirus is able to use the specific state of alveolar macrophages to escape from the endocytosis and in turn use macrophages to reproduce themselves.Huang said the process depends on a proteolytic enzyme (CTSL) in the endocytic body and the pH of the endocytic sac.At acidic pH, CTSL is activated and hydrolyzes novel Coronavirus spike proteins, resulting in the release of viral genetic material RNA into the cytoplasm, initiating viral replication and amplification.Under normal physiological conditions, the pH value of alveolar macrophage endocytosis is alkaline, and the Novel coronavirus phagocytosis is sent to lysosome for degradation, so that the body shows no symptoms or mild symptoms.Based on this, huangbo’s team identified two novel Coronavirus drugs that block novel Coronavirus escape from the endocytosomes of alveolar macrophages in a COVID-19 mouse drug screening test.”Bisphosphonates such as Alendronate (ALN) are clinically used in the treatment of osteoporosis by targeting macrophages;Dexamethasone (Dex), a glucocorticoid, is commonly used as an anti-inflammatory.”We found that Dex and ALN can synergistically block virus escape from the endocytoid by targeting CTSL expression and endocytoid pH, respectively, Huang said.Huang said the effect of such a combination therapy is achieved through local administration of nasal spray, while systemic administration is difficult to produce results due to the obstruction of the alveolar surfactant layer.The combination also acts as a hormonal anti-inflammatory.This spray therapy is simple, safe, low-cost, and easy to popularize. It is a new strategy for the early control of Novel coronavirus infection that deserves further study.Source: Science and Technology Daily