Genomic Epidemiology of Imported Cases of COVID-19 in Guangdong Province, China, October 2020 - May 2021.

Objective: The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been engendering enormous hazards to the world. We obtained the complete genome sequences of SARS-CoV-2 from imported cases admitted to the Guangzhou Eighth People's Hospital, which was appointed by the Guangdong provincial government to treat coronavirus disease 2019 (COVID-19). The SARS-CoV-2 diversity was analyzed, and the mutation characteristics, time, and regional trend of variant emergence were evaluated. Methods: In total, 177 throat swab samples were obtained from COVID-19 patients (from October 2020 to May 2021). High-throughput sequencing technology was used to detect the viral sequences of patients infected with SARS-CoV-2. Phylogenetic and molecular evolutionary analyses were used to evaluate the mutation characteristics and the time and regional trends of variants. Results: We observed that the imported cases mainly occurred after January 2021, peaking in May 2021, with the highest proportion observed from cases originating from the United States. The main lineages were found in Europe, Africa, and North America, and B.1.1.7 and B.1.351 were the two major sublineages. Sublineage B.1.618 was the Asian lineage (Indian) found in this study, and B.1.1.228 was not included in the lineage list of the Pangolin web. A reasonably high homology was observed among all samples. The total frequency of mutations showed that the open reading frame 1a (ORF1a) protein had the highest mutation density at the nucleotide level, and the D614G mutation in the spike protein was the commonest at the amino acid level. Most importantly, we identified some amino acid mutations in positions S, ORF7b, and ORF9b, and they have neither been reported on the Global Initiative of Sharing All Influenza Data nor published in PubMed among all missense mutations. Conclusion: These results suggested the diversity of lineages and sublineages and the high homology at the amino acid level among imported cases infected with SARS-CoV-2 in Guangdong Province, China.

Krüppel-like factor 17 inhibits urokinase plasminogen activator gene expression to suppress cell invasion through the Src/p38/ MAPK signaling pathway in human lung adenocarcionma.

Krüppel-like factor 17 (KLF17) has been reported to be involved in invasion and metastasis suppression in lung cancer, but the molecular mechanisms underlying the anti-invasion and anti-metastasis roles of KLF17 in lung cancer are not fully illustrated. Here, we showed that KLF17 inhibited the invasion of A549 and H322 cells; the anti-invasion effect of KLF17 was associated with the suppression of urokinase plasminogen activator (uPA/PLAU) expression. KLF17 can bind with the promoter of uPA and inhibit its expression. Enforced expression of uPA abrogated the anti-invasion effect of KLF17 in A549 and H322 cells. In addition, immunohistochemistry staining showed that the protein expression of KLF17 was negatively correlated with that of uPA in archived samples from patients with lymph node metastasis of lung adenocarcinoma (rho = -0.62, P = 0.01). The mutually exclusive expression of KLF17 with uPA could predict lymph node metastasis for lung adenocarcinoma (AUC = 0.758, P = 0.005). Enforced expression of KLF17 inhibited the expression of phosphorylated Src and phosphorylated p38/MAPK in A549 and H322 cells. The invasiveness of the cells were suppressed by treating with sb203580 (p38/MAPK inhibitor) or HY-13805 (PP2, Src inhibitor). furthermore, p38/MAPK inhibition could block the KLF17-induced reduction of p-p38/MAPK and uPA, and Src inhibition enhanced the KLF17-induced suppression of p-Src and uPA in A549 and H322 cells. In conclusion, our study indicated that KLF17 suppressed the uPA-mediated invasion of lung adenocarcinoma. The Src and p38/MAPK signaling pathways were suggested as mediators of KLF17-induced uPA inhibition, thus providing evidence that KLF17 might be a potential anti-invasion candidate for lung adenocarcinoma.

Influence of chronic HBV infection on superimposed acute hepatitis E.

AIM: To investigate the influence of chronic hepatitis B virus (HBV) infection [based on the status of hepatitis B e antigen (HBeAg), HBV DNA, and cirrhosis] on superimposed acute hepatitis E. METHODS: A total of 294 patients were recruited from the Department of Infectious Diseases of the Third Affiliated Hospital, Sun Yat-sen University, from January 2003 to January 2012. The patients were classified into two groups: an HBV + hepatitis E virus (HEV) group (a group with chronic HBV infection that was superinfected with acute hepatitis E, n = 118) and an HEV group (a group with acute hepatitis E, n = 176). We retrospectively analyzed and compared the clinical features of the two groups. Statistical analyses were performed using the χ(2) test or Fisher's exact test for categorical variables and the Student's t test for continuous variables. A P value < 0.05 was considered statistically significant. RESULTS: The peak values of prothrombin time, serum total bilirubin, and Model for End-Stage Liver Disease scores were significantly higher in the HBV + HEV group. More patients in the HBV + HEV group had complications (39.8% vs 16.5%, P = 0.000) and developed liver failure (35.6% vs 8.5%, P = 0.000). Additionally, the mortality of the HBV + HEV group was significantly higher (20.3% vs 7.4%, P = 0.002). Further analysis of the HBV + HEV group showed that there were no significant differences in complication occurrence, liver failure incidence, or mortality between patients with different HBeAg and HBV DNA statuses. However, in patients with underlying cirrhosis, complication occurrence and liver failure incidence significantly increased. In total, 12.7% of the patients in the HBV + HEV group received anti-HBV treatment, but this therapy failed to reduce mortality in patients who developed liver failure. CONCLUSION: The presence of underlying cirrhosis in chronic HBV infection results in more severe clinical outcomes with superimposed acute hepatitis E. Anti-HBV treatment cannot improve the prognosis of liver failure caused by HBV-HEV superinfection.

[Interleukin-32 expression is induced by hepatitis B virus].

OBJECTIVE: To investigate whether hepatitis B virus (HBV) can induce the expression of the host-encoded cytokine interleukin-32 (IL-32) and its effects on host signaling mechanisms related to HBV pathogenesis. METHODS: A eukaryotic expression vector harboring an enhanced green fluorescent protein was constructed with HBV genomic sequences (pIRES2-HBV-EGFP) and transfected into HepG2 cells. In addition, the nuclear factor-kappa B (NF-kB) subunits, p50 and p65, were transfected respectively into HepG2 cells. In both cases, 48 hrs after transfection, IL-32 expression was determined at the mRNA and protein levels using real-time PCR and ELISA and western blot, respectively. The HepG2 cells transfected with pIRES2-HBV-EGFP were also treated with the NF-kB inhibitor SN50 at various concentrations, and the effects on IL-32 protein expression 48 hrs later were evaluated by western blot. Significance of between-group differences was assessed by the Student's t-test. RESULTS: Transfection with pIRES2-HBV-EGFP led to significantly higher IL-23 expression than transfection with empty vector (mRNA: 2.8-fold higher and protein: 4.5-fold higher; both P less than 0.05). Transfection of p50 and p65 proteins led to significantly higher IL-32 expression (both P less than 0.05), and NF-kB activation was found to be required for HBV-induced IL-32 expression. CONCLUSION: IL-32 expression is induced by HBV in HepG2 cells. This host-encoded cytokine, and its downstream activation of NF-kB, may be involved in the pathogenesis of HBV, especially in the subsequent liver inflammation that accompanies HBV infection.

[Comparative study on the clinical characteristics of HBV infection patients with different pathologic inflammation grade].

OBJECTIVE: The aim of this study was to compare the biochemical and virological characteristics among patients infected with hepatitis B virus (HBV) according to pathologic inflammation grade. METHODS: 428 patients with chronic HBV infection accept liver biopsy, liver function test, HBeAg detection and HBV DNA levels detection. They were studied and subdivided into four groups according to pathologic inflammation grade. The biochemical and virological characteristics were studied. Univariate analysis was performed with the SPSS 16.0. RESULTS: In different inflammation grading group, mean age and sex composition were no difference. Serum levels of ALT was highest in group G3 and lowet in group G0-1, there was statistically significant among groups (P = 0.005); AST and TBil were all highest in group G4 and lowest in group G0-1, statistically significant also found among groups (P = 0.000 & 0.004). Serum levels of ALB and PTA were all highest in group G0-1 and lowest in group G4, had statistically significant among groups (P = 0.000 & 0.000). There was no difference of HBV DNA level and percentage of HBeAg (+) among four groups (P = 0.565 & 0.065). CONCLUSIONS: The serum AST, TBil, ALB and PTA were different and can partly reflect the inflammation degree of liver damage in patients with HBV infection. ALT and PTA can reflect the inflammation degree of G0-1, G2 and G3; AST, TBil, ALB and PTA reflect the G3 and G4. HBV DNA level and HBeAg status can not indicate the inflammation degree in HBV infection patients.

[Determination of serum IL-23 and its significance in patients with severe chronic hepatitis B].

OBJECTIVE: To investigate the level of the serum IL-23 and its correlation with serum biochemical indices of liver function tests and HBV DNA load in patients with chronic severe hepatitis B. METHODS: Fifty patients with chronic severe hepatitis B (severe hepatitis group) and 18 healthy controls (control group) were enrolled in the study. The serum IL-23 expression level was detected by ELISA method. The correlation between IL-23 and ALT, AST, TBil, HBV DNA load was analyzed using Pearson's correlation analysis, respectively. RESULTS: Serum IL-23 expression level in severe hepatitis group was significantly higher than that of control group (P < 0.05). Serum IL-23 level was positively correlated with serum ALT, AST, respectively (P < 0.05), but was not correlated with TBil and HBV DNA load, respectively (P > 0.05). CONCLUSION: Serum IL-23 expression level was increased in patients with chronic severe hepatitis B and was associated with the severe of inflammation. We, therefore, believe that IL-23 might be involved in the pathogenesis of chronic severe hepatitis B.

[MicroRNA differential expression profiles in DC after the stimulation of HBsAg].

OBJECTIVE: To establish the differential expression profiles for exploring new immune mechanism of hepatitis B virus infection. METHODS: DCs were separated from the bone marrow of healthy mouse and cultured in vitro. Then DCs were stimulated with HBsAg, LPS, TNF-alpha, respectively. Twenty-four hours later, the total RNA of cell was extracted. cDNA microarray was used to compare the differential expression of RNA. The significant differential expression of miRNA after the stimulation of HBsAg was chosen. Subsequently, target genes of the significant differential miRNA were forecasted by using computer software. RESULTS: There were 30 miRNAs whose significant differential expressions were beyond two times after the stimulation of HBsAg. Among them, 16 miRNAs expressions were increased and 14 miRNAs expressions were decreased. There was significant difference in differential expression of miRNA among the 3 different stimulations. The selected target genes included relevant elements of signal pathway of DC. CONCLUSION: The alteration of expression profiles of miRNA was specific after DC was stimulated by HBsAg. The selected target genes further demonstrated that miRNA could play important roles in the immune mechanism of HBV infection.

[Interleukin-21 expression in serum of patients with acute-on-chronic liver failure and its significance].

OBJECTIVE: To investigate the level of the serum IL-21 and its correlation with serum biochemical indices of liver function test in patients with acute-on-chronic liver failure. METHODS: Sixty patients with acute-on-chronic liver failure (severe hepatitis group) and 18 normal cases (control group) were enrolled in the study. Peripheral blood lymphocytes were isolated and total RNA of lymphocytes was extracted by using Trizol. Real-time PCR was used to assay IL-21 mRNA level. The serum IL-21 expression level was detected by ELISA method. The correlation between IL-21 and ALT, AST, TBiL, ALB was analyzed using Pearson's correlation analysis, respectively. RESULTS: Serum IL-21 expression level in severe hepatitis group was higher than that of control group. Moreover, the difference between them was statistically significant (P < 0.05). Serum IL-21 level was positively correlated with serum ALT, AST, TBil, respectively (P < 0.05), but was negatively correlated with ALB, respectively (P < 0.05). CONCLUSION: Serum IL-21 expression level was increased in patients with acute-on-chronic liver failure and was associated with the severe of inflammation. We, therefore, believe that IL-21 might be involved in the pathogenesis of acute-on-chronic liver failure and might be an index of the severity of liver inflammation.

[Expression of fibroblast activation protein in HBV related hepatocellular carcinoma].

OBJECTIVE: To analyze the gene expression level of fibroblast activation protein in HBV related hepatocellular carcinoma patients and discuss its clinical significance. METHODS: FAP gene expression in 33 hepatocellular carcinoma patients cancer tissues, peficancerous tissues, distant relative normal liver tissues and 13 normal liver tissues were examined by reverse transcription PCR; and real-time fluorescent quantitative PCR (qRT-PCR) was used to quantify their expression. RESULTS: FAP were expressed in all the tissues,the relative expression values in cancer tissues, peficancerous tissues and distant relative normal liver tissues were 5.14 +/- 6.69, 1.58 +/- 0.96, 1.63 +/- 0.94, respectively, the differences were statistically significant (F = 4.401, P < 0.05); and in TNM stage I, II, IIII, they were 2.89 +/- 3.35, 4.15 +/- 4.69, 10.09 +/- 9.51 respectively; in well-differentiated, differentiated and poorly differentiated hepatocellular carcinoma were 1.62 +/- 1.74, 3.84 +/- 3.79, 1.26 +/- 13.34 respectively. The differences were all statistically significant (P < 0.05). CONCLUSION: FAP may play an important role in the occurrence and development of HBV related hepatocellular carcinoma.

[MiR-196a-2 gene polymorphism and the antiviral therapy of chronic hepatitis C].

OBJECTIVE: To investigate the relationship between the SNP rs11614913 on miR196a-2 gene and the treatment effects of Peg-IFN-a plus Ribavirin on chronic hepatitis C patients. METHODS: The total 139 patients of chronic hepatitis C infection who received the treatment of Peg-IFN-alpha-2a or Peg-IFN-alpha-2b plus Ribavirin were enrolled in this study. The patients were divided into two groups: sustained virological response (SVR) (n = 82) group and non virological response (NVR) or recurrence (n = 57) group. Blood samples were collected and chromosomal DNA was extracted. The miR-196a-2 polymorphism was determined with the method of polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). RESULTS: In our study, there was statistically association between miR-196a-2 polymorphism and the antiviral therapy efficacy of hepatitis C patients. There was statistically significance in the CT genotype and the TT genotype of miR-196a-2 between the two groups [P = 0.009, A = 2.924 (1.285 -6.652)]. There was statistically significance in the CC genotype and the TT genotype between the two groups [P = 0.036, A = 3.091(1.052 -9.078)]. There was statistically significance in the C allele and the T allele between the two groups [P = 0.036, A = 3.091 (1.052 - 9.078)]. CONCLUSION: These findings suggested that the rs11614913 SNP in miR - 196a-2 be associated with the antiviral therapy efficacy of hepatitis C patients, and the TT genotype or T alleles be associated with the SVR while the CC genotype or C allele could be related to the NVR or recurrence.

An anti-transferrin receptor antibody enhanced the growth inhibitory effects of chemotherapeutic drugs on human non-hematopoietic tumor cells.

Transferrin receptor (TfR) has been used as a target for antibody-based therapy of cancer. Combining anti-TfR antibodies with chemotherapeutic drugs shows potential as one of the strategies for cancer therapy. In this study, we investigated the effects of anti-TfR monoclonal antibody 7579 alone or in combination with chemotherapeutic drugs (5-fluorouracil or doxorubicin) on non-hematopoietic tumor cells (HepG2 and MCF-7) in vitro. We found that 7579 mAb alone could dramatically down-regulate surface TfR expression on tumor cells. Consequently, marked S phase arrest and apoptosis were observed in 7579 mAb-treated tumor cells. In combination with 5-fluorouracil or doxorubicin, 7579 mAb enhanced the growth inhibitory effects of chemotherapeutic drugs on tumor cells. Results of 7AAD/Annexin V staining demonstrated that 7579 mAb enhanced the cytotoxic effects of chemotherapeutic drugs on tumor cells by mainly promoting tumor cell necrosis. Using the median-effect/combination-index isobologram method, we further evaluated the nature of 7579 mAb/chemotherapeutic drug interactions. Synergistic interaction was observed for 7579 mAb combined with 5-fluorouracil whereas additive efficacy was observed for 7579 mAb plus doxorubicin. Our study provided the basis to further develop 7579 mAb-containing chemoimmunotherapy for non-hematopoietic malignancies.