Serologic Response to SARS-CoV-2 in COVID-19 Patients with Different Severity.

The immense patient number caused by coronavirus disease 2019 (COVID-19) global pandemic brings the urge for more knowledge about its immunological features, including the profile of basic immune parameters. In this study, eighty-eight reported COVID-19 patients in Wuhan were recruited from January to February, 2020, including 32 severe/critical cases and 56 mild/moderate cases. Their mean age was 56.43 years (range 17-83) and gender ratio (male/female) was 43:45. We tested SARS-CoV-2 RNA with commercial kits, investigated the level of serologic IgM and IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using magnetic particle chemiluminescence immunoassays, and compared the results of serologic tests and nucleic acid test (NAT). Among 88 patients, 95.45% were confirmed as positive by the combination of NAT and antibody test, which was significantly higher (P < 0.001) than by single nucleic acid test (73.86%) or serologic test (65.91%). Then the correlation between temporal profile and the level of antibody response was analyzed. It showed that seroconversion started on day 5 after disease onset and IgG level was rose earlier than IgM. Comparison between patients with different disease severity suggested early seroconversion and high antibody titer were linked with less severe clinical symptoms. These results supported the combination of serologic testing and NAT in routine COVID-19 diagnosis and provided evidence on the temporal profile of antibody response in patients with different disease severity.

Upregulation of microRNA-210 regulates renal angiogenesis mediated by activation of VEGF signaling pathway under ischemia/perfusion injury in vivo and in vitro.

BACKGROUND: MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs that regulate gene expression and function, but little is known about regulation of miRNAs in the kidneys under normal or pathologic conditions. Here, we sought to investigate the potential involvement of miRNAs in renal ischemia/reperfusion (I/R) injury and angiogenesis and to define some of the miRNAs possibly associated with renal angiogenesis. METHODS AND RESULTS: Male Balb/c mice were subjected to a standard renal I/R. CD31 immunostaining indicated a significant increase of microvessels in the ischemic region. VEGF and VEGFR2 expression were increased in renal I/R at both the mRNA and protein levels which were detected by qRT-PCR and Western blot, respectively. More importantly, 76 microRNAs exhibited more than 2-fold changes using Agilent microRNA microarray, which contains downregulation of 40 miRNAs and upregulation of 36 miRNAs. Upregulation of miR-210 was confirmed by qRT-PCR with prominent changes at 4 and 24 h after reperfusion. Furthermore, overexpression of miR-210 in HUVEC-12 cells enhances VEGF and VEGFR2 expression and promotes angiogenesis on Matrigel in vitro. CONCLUSION: These findings suggest miR-210 may be involved in targeting the VEGF signaling pathway to regulate angiogenesis after renal I/R injury, which provides novel insights into the angiogenesis mechanism of renal I/R injury.

[Change in expression of vascular endothelial growth factor in serum and wound tissue of rats with electrical burns].

OBJECTIVE: To observe the change in expression of vascular endothelial growth factor (VEGF) in serum and wound tissue of rats with electrical burn (EB), and to explore its regulation mechanism in the pathological changes of EB. METHODS: Sixty-four SD rats were divided into normal control group (n = 8) and EB group (n = 56) according to the random number table. Eight rats in EB group were sacrificed at post injury hour (PIH) 6 and on post injury day (PID) 1, 3, 7, 14, 21, and 28, to collect wound muscle tissue and serum samples. Histopathological changes in wound tissue were observed with HE staining. The serum content of VEGF was determined with double-antibody sandwich enzyme-linked immunosorbent assay. The expression level of VEGF in wound tissue was determined with Western blotting. VEGF expression intensity in wound tissue was observed with immunohistochemical staining. The microvessel density (MVD) was calculated. The correlation between VEGF expression intensity and MVD was analyzed. Muscle tissue of calf and serum of the rats in normal control group without any treatment were collected for above-mentioned observations and determinations. Data were processed with one-way analysis of variance and Spearman hierarchy correlation analysis, and LSD-t test was applied for paired comparison. RESULTS: (1) In EB group, breakage of muscle fiber, heavy infiltration of inflammatory cells, and obvious tissue edema were observed at PIH 6 and on PID 1; new vessels were observed on PID 3; amount of granulation tissue and number of new vessels were found to be increased on PID 7. (2) In EB group, the serum level of VEGF was (43 ± 11) pg/mL at PIH 6, (44 ± 11) pg/mL on PID 1, and (74 ± 27) pg/mL on PID 14, which were all significantly higher than that in normal control group [(15 ± 9) pg/mL, with t values from 4.001 to 5.724, P values all below 0.01]. (3) The protein expression level of VEGF of wound tissue in EB group was higher than that in normal control group (0.21 ± 0.09) at each time point. The protein expression level of VEGF in EB group peaked on PID 7 (0.63 ± 0.13, t = 4.965, P < 0.05). (4) In EB group, strongly positive expression of VEGF was observed in inflammatory cells at early stage and in new vascular endothelial cells at late stage. (5) The expression intensity of VEGF was positively correlated with MVD in wound tissue on PID 3, 7, 14, 21, and 28 in EB group (r(s) = 0.834, P < 0.01). CONCLUSIONS: Different expression levels of VEGF were observed in serum and wound tissue of rats at various stages after EB, and they were closely correlated with different stages of fluid exudation and wound healing process after EB.