RESUMEN
Objective:To study the effect of Long non-coding RNA(LncRNA)small nucleolar RNA host gene 12(SNHG12)regulating miR-138-5p/hypoxia inducible factor-1(HIF-1α)axis on improving the damage of hypoxia/reoxygenation(H/R)human vas-cular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were cultured in vitro and randomly divided into control group,H/R model group,H/R+LncRNA SNHG12 overexpression group,H/R+miR-138-5p mimics group,H/R+co-transfec-tion group and H/R+co-transfection negative control group,each transfection group was transfected separately,and except for control group,the remaining groups were given hypoxia for 5 hours and then reoxygenated for 1 hour to induce the cell models,and then the cell viability of each group was detected by CCK-8 experiment;the cell apoptosis in each group was detected by flow cytometry experi-ment,and the apoptosis rate of each group was compared;the levels of reactive oxygen species(ROS),lactate dehydrogenase(LDH)and inflammatory factors IL-6,IL-17 and IL-18 in each group were measured by the kit;the expressions of miR-138-5p and HIF-1α mRNA in cells of each group were measured by real-time quantitative PCR(qRT-PCR)experiment;the expressions of apoptotic pro-teins caspase-9,Bcl-2-associated X protein(Bax)and HIF-1α in each group were evaluated by Western blot.Results:Compared with control group,the apoptosis rate,cellular ROS,LDH,IL-6,IL-17 and IL-18 levels,cellular HIF-1α mRNA and protein levels,cellular caspase-9,Bax and HIF-1α protein levels were increased in H/R model group(P<0.05),the cell viability and miR-138-5p level were decreased(P<0.05).Compared with H/R model group and H/R+co-transfection group,the cell viability,cell HIF-1αmRNA and protein levels were increased in H/R+LncRNA SNHG12 overexpression group(P<0.05),the apoptosis rate,cellular ROS,LDH,IL-6,IL-17 and IL-18 levels,cellular caspase-9 and Bax protein levels,and miR-138-5p level were decreased(P<0.05);the cell viability,cellular HIF-1α mRNA and protein levels were decreased in H/R+miR-138-5p mimics group(P<0.05),the apoptosis rate,cellular ROS,LDH,IL-6,IL-17 and IL-18 levels,cellular caspase-9 and Bax protein levels were increased(P<0.05).Com-pared with H/R model group,there was no significant difference in cell index levels between the H/R+co-transfection negative control group and the H/R+co-transfection group(P>0.05).Conclusion:LncRNA SNHG12 can upregulate HIF-1α expression by downregulat-ing miR-138-5p expression,inhibit H/R-induced inflammation and oxidative stress in HUVECs,and reduce cell damage and apoptosis.
RESUMEN
In spite of the successful development of effective countermeasures against Covid-19, variants have and will continue to emerge that could compromise the efficacy of currently approved neutralizing antibodies and vaccines. Consequently, novel and more efficacious agents are urgently needed. We have developed a bispecific antibody, 2022, consisting of two antibodies, 2F8 and VHH18. 2F8 was isolated from our proprietary fully synthetic human IDEAL (Intelligently Designed and Engineered Antibody Library)-VH/VL library and VHH18 is a single domain antibody isolated from IDEAL-nanobody library. 2022 was constructed by attaching VHH18 to the C-terminal of Fc of 2F8. 2022 binds two non-overlapping epitopes simultaneously on the RBD of the SARS-CoV-2 spike protein and blocks the binding of RBD to human angiotensin-converting enzyme 2 (ACE2). 2022 potently neutralizes SARS-CoV-2 and all of the variants tested in both pseudovirus and live virus assays, including variants carrying mutations known to resist neutralizing antibodies approved under EUA and that reduce the protection efficiency of current effective vaccines. The half-maximum inhibitory concentration (IC50) of 2022 is 270 pM, 30 pM, 20 pM, and 1 pM, for wild-type, alpha, beta, and delta pseudovirus, respectively. In the live virus assay, 2022 has an IC50 of 26.4 pM, 13.3 pM, and 88.6 pM, for wild-type, beta, and delta live virus, respectively. In a mouse model of SARS-CoV-2, 2022 showed strong prophylactic and therapeutic effects. A single administration of 2022 intranasal (i.n.) or intraperitoneal (i.p.) 24 hours before virus challenge completely protected all mice from bodyweight loss, as compared with up to 20% loss of bodyweight in placebo treated mice. In addition, the lung viral titers were undetectable (FRNT assay) in all mice treated with 2022 either prophylactically or therapeutically, as compared with around 1x105 pfu/g lung tissue in placebo treated mice. In summary, bispecific antibody 2022 showed potent binding and neutralizing activity across a variety of SARS-CoV-2 variants and could be an attractive weapon to combat the ongoing waves of the COVID-19 pandemic propagated mainly by variants, especially, the much more contagious delta variant.