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Updated: Oct 14, 2025
Measurement of Chitinase Activity in Biological Samples
Published on: August 22, 2019
Chitinase 3-like-1 is a therapeutic target that mediates the effects of aging in COVID-19
Suchitra Kamle1, Bing Ma1, Chuan Hua He1
1Molecular Microbiology and Immunology.
Abstract:
COVID-19 is caused by SARS-CoV-2 (SC2) and is more prevalent and severe in elderly and patients with comorbid diseases (CM). Because chitinase 3-like-1 (CHI3L1) is induced during aging and CM, the relationships between CHI3L1 and SC2 were investigated. Here, we demonstrate that CHI3L1 is a potent stimulator of the SC2 receptor angiotensin converting enzyme 2 (ACE2) and viral spike protein priming proteases (SPP), that ACE2 and SPP are induced during aging, and that anti-CHI3L1, kasugamycin, and inhibitors of phosphorylation abrogate these ACE2- and SPP-inductive events. Human studies also demonstrate that the levels of circulating CHI3L1 are increased in the elderly and patients with CM, where they correlate with COVID-19 severity. These studies demonstrate that CHI3L1 is a potent stimulator of ACE2 and SPP, that this induction is a major mechanism contributing to the effects of aging during SC2 infection, and that CHI3L1 co-opts the CHI3L1 axis to augment SC2 infection. CHI3L1 plays a critical role in the pathogenesis of and is an attractive therapeutic target in COVID-19.
Insights
Chitinase 3-like-1 (CHI3L1) significantly increases SARS-CoV-2 (SC2) severity in older adults and those with comorbidities by stimulating the SC2 receptor ACE2 and proteases. Targeting CHI3L1 may offer a new COVID-19 therapeutic strategy.
Area of Science:
- Virology
- Immunology
- Gerontology
Background:
- COVID-19, caused by SARS-CoV-2 (SC2), presents higher prevalence and severity in elderly individuals and those with comorbid diseases (CM).
- Chitinase 3-like-1 (CHI3L1) levels are known to increase with aging and in the presence of CM.
Purpose of the Study:
- To investigate the relationship between CHI3L1 and SC2 infection.
- To determine the role of CHI3L1 in the heightened severity of COVID-19 in vulnerable populations.
Main Methods:
- Investigated CHI3L1's effect on SC2 receptor (ACE2) and spike protein priming proteases (SPP).
- Examined the induction of ACE2 and SPP during aging.
- Assessed the impact of anti-CHI3L1, kasugamycin, and phosphorylation inhibitors.
- Correlated circulating CHI3L1 levels with COVID-19 severity in human studies.
Main Results:
- CHI3L1 was identified as a potent stimulator of ACE2 and SPP.
- ACE2 and SPP were found to be induced during aging.
- Anti-CHI3L1, kasugamycin, and phosphorylation inhibitors effectively blocked ACE2 and SPP induction.
- Elevated CHI3L1 levels in elderly and comorbid patients correlated with increased COVID-19 severity.
Conclusions:
- CHI3L1 significantly contributes to the pathogenesis of SC2 infection, particularly in aging individuals.
- CHI3L1 enhances SC2 infection by stimulating ACE2 and SPP, representing a key mechanism in age-related COVID-19 severity.
- CHI3L1 emerges as a promising therapeutic target for COVID-19.
