Clinical and immunological features of convalescent pediatric patients infected with the SARS-CoV-2 Omicron variant in Tianjin, China.

COVID-19 has spread surprisingly fast worldwide, and new variants continue to emerge. Recently, the World Health Organization acknowledged a new mutant strain "Omicron", with children were accounting for a growing share of COVID-19 cases compared with other mutant strains. However, the clinical and immunological characteristics of convalescent pediatric patients after Omicron infection were lacking. In this study, we comparatively analyzed the clinical data from pediatric patients with adult patients or healthy children and the effects of SARS-CoV-2 vaccine on the clinical and immune characteristics in convalescent pediatric patients. Our results indicated that convalescent pediatric patients had unique clinical and immune characteristics different from those of adult patients or healthy children, and SARS-CoV-2 vaccination significantly affected on the clinical and immune characteristics and the prevention of nucleic acid re-detectable positive (RP) in convalescent patients. Our study further deepens the understanding of the impact of Omicron on the long-term health of pediatric patients and provides a valuable reference for the prevention and treatment of children infected with Omicron.

Identification of milRNAs and their target genes in Ganoderma lucidum by high-throughput sequencing and degradome analysis.

MicroRNAs (miRNAs in animals and plants or milRNAs in fungi) are endogenous noncoding RNAs that can regulate gene expression. However, little information is known about milRNAs and their target genes in Ganoderma lucidum. Here, we systematically predicted and characterised the milRNAs and their target genes across the three developmental stages of G. lucidum. A total of 168 unique milRNAs were predicted using a small RNA sequencing method. For them, 1612 target sequences corresponding to 1311 unique genes were predicted by degradome sequencing. We selected 42 predicted milRNAs and performed RT-PCR amplification and Sanger sequencing of the products. Five products were found to have sequences similar to those predicted, confirming the presence of milRNAs in G. lucidum, and demonstrating the difficulty in their validation. Among the 168 milRNAs, 111 were found to be significantly differentially expressed across the three developmental stages (q ≤ 0.05). The expression levels of 12 milRNAs were measured by stem-loop quantitative real-time polymerase chain reaction. Eight of them were in line with the sequencing results (r ≥ 0.9, p ≤ 0.05). These 12 milRNAs and their target genes form 16 milRNA-target gene pairs. The expression profiles of 8 of these 16 miRNA-target pairs were negatively correlated, according to real-time quantitative analysis, whereas the other eight pairs were positively correlated. Furthermore, the results of functional enrichment analysis showed that the target genes of milRNAs mapped to the Gene Ontology terms 'GTP binding' and 'FAD binding' were enriched in specific developmental stages. These target genes were related to the biosynthesis of triterpenes and polysaccharides and lignin degradation pathway in G. lucidum. In summary, this study indicates that milRNAs may play crucial regulatory roles in various biological processes of G. lucidum and open up new avenues for research on milRNAs' biosyntheses and functions in basidiomycetes.

MicroRNA-146a inhibits NF-κB activation and pro-inflammatory cytokine production by regulating IRAK1 expression in THP-1 cells.

MicroRNA (miR)-146a levels are reduced in peripheral blood mononuclear cells of patients with systemic lupus erythematosus (SLE); however, its function is not well understood. The present study investigated the role of miR-146a in the regulation of lipopolysaccharide (LPS)-induced inflammation in THP-1 cells. A miR-146a mimic and an inhibitor were used to overexpress and downregulate miR-146a expression, respectively. Reverse transcription-quantitative PCR and western blot analyses were performed to evaluate interleukin (IL)-1 receptor-associated kinase 1 (IRAK1) expression, and western blot analysis was applied to assess nuclear factor-κB activation by analyzing p65 subunit levels in the nucleus. To investigate the effects of miR-146a on LPS-induced inflammation, IL-6 and tumor necrosis factor-α (TNF-α) levels were also measured using ELISA. The results of the present study revealed thatmiR-146a overexpression significantly reduced IRAK1 expression, reduced p65 levels in the nucleus and reduced IL-6 and TNF-α levels in the supernatant of the cell culture medium of THP-1 cells following LPS treatment. Luciferase assays confirmed IRAK1 to be a direct target of miR-146a in THP-1 cells. In conclusion, miR-146a may regulate IRAK1 expression and inhibit the activation of inflammatory signals and secretion of pro-inflammatory cytokines. The present study revealed, at least in part, the mechanisms by which miR-146a regulate the inflammatory response in SLE.