Abstract
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection can result in more severe syndromes and poorer outcomes in patients with diabetes and obesity.However,the precise mechanisms responsible for the combined impact of coronavirus disease 2019(COVID-19)and diabetes have not yet been elucidated,and effective treatment options for SARS-CoV-2-infected diabetic patients remain limited.To investigate the disease pathogenesis,K18-hACE2 transgenic(hACE2Tg)mice with a leptin receptor deficiency(hACE2-Lepr-/-)and high-fat diet(hACE2-HFD)background were generated.The two mouse models were intranasally infected with a 5x105 median tissue culture infectious dose(TCID50)of SARS-CoV-2,with serum and lung tissue samples collected at 3 days post-infection.The hACE2-Lepr-/-mice were then administered a combination of low-molecular-weight heparin(LMWH)(1 mg/kg or 5 mg/kg)and insulin via subcutaneous injection prior to intranasal infection with 1×104 TCID50 of SARS-CoV-2.Daily drug administration continued until the euthanasia of the mice.Analyses of viral RNA loads,histopathological changes in lung tissue,and inflammation factors were conducted.Results demonstrated similar SARS-CoV-2 susceptibility in hACE2Tg mice under both lean(chow diet)and obese(HFD)conditions.However,compared to the hACE2-Lepr+/+mice,hACE2-Lepr-/-mice exhibited more severe lung injury,enhanced expression of inflammatory cytokines and hypoxia-inducible factor-1a(HIF-1a),and increased apoptosis.Moreover,combined LMWH and insulin treatment effectively reduced disease progression and severity,attenuated lung pathological changes,and mitigated inflammatory responses.In conclusion,pre-existing diabetes can lead to more severe lung damage upon SARS-CoV-2 infection,and LMWH may be a valuable therapeutic approach for managing COVID-19 patients with diabetes.
基金项目
Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB29010102)
National Natural Science Foundation of China(NSFC)(91957124)
National Natural Science Foundation of China(NSFC)(82161148010)
National Natural Science Foundation of China(NSFC)(32041010)
Selfsupporting Program of Guangzhou Laboratory(SRPG22-001)
National Science and Technology Infrastructure of China(National Pathogen Resource Center)(NPRC-32)
China Health Promotion Foundation()
Youth Innovation Promotion Association of CAS(Y2021034)
Innovation Team and Talents Cultivation Program of the National Administration of Traditional Chinese Medicine(ZYYCXTD-D-202208)