Establishing an internal quality control method for the stable extraction of nucleic acids of severe acute respiratory syndrome coronavirus 2 and RT-PCR-based detection

Secretory phosphoprotein 1 secreted by fibroblast-like synoviocytes promotes osteoclasts formation via PI3K/AKT signaling in collagen-induced arthritis

Synovial tissue hyperplasia is a major cause of bone damage in rheumatoid arthritis (RA). Over-proliferation and secretion of cytokines of fibroblast-like synoviocytes (FLSs) are key contributors to bone damage in the joint microenvironment. Therefore, inhibition of FLSs-mediated bone damage is of great significance in RA patients. The aim of this study was to investigate the molecular mechanisms by which FLSs-mediated bone damage in the joint microenvironment. The results of whole transcriptome sequencing showed that Spp1 gene expression was significantly upregulated in collagen-induced arthritis FLSs compared to Normal FLSs. KEGG enrichment analysis revealed up-regulated Spp1 gene expression, associated with PI3K/AKT signaling. Animal and cellular experiments were designed to validate and explore the results of sequencing. Briefly, the data demonstrated secretory phosphoprotein 1 (SPP1) (encoded by Spp1 gene) secreted by FLSs promotes osteoclasts differentiation in vivo and in vitro and exacerbates articular bone damage in collagen-induced arthritis mice. Interestingly, SPP1 secreted by FLSs does not affect its own proliferation and apoptosis. The results of co-culture of FLSs with bone marrow-derived monocytes indicated the level of SPP1 secreted by FLSs positively correlates with the frequency of p-PI3K⁺PI3K⁺ osteoclasts, whereas not with the frequency of p-AKT⁺AKT⁺ osteoclasts. This may suggest that SPP1 secreted by FLSs acts directly on PI3K while indirectly on AKT. Together, the results revealed SPP1 secreted by FLSs promotes osteoclasts formation via PI3K/AKT signaling in collagen-induced arthritis. Regulation of Spp1 gene expression in FLSs may be a potential approach to treat RA bone damage in the joint microenvironment.

Establishing an internal quality control method for the stable extraction of nucleic acids of severe acute respiratory syndrome coronavirus 2 and RT-PCR-based detection

Background

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the causative agent of the coronavirus disease 2019 (COVID‐19), is detected using real‐time RT‐PCR. However, there are limitations pertaining to quality control, particularly with respect to establishing quality control measures for extraction of viral nucleic acids. Here, we investigated the quality control measures for the various processes using an extrinsic quality control substance and quality control charts.

Methods

An extrinsic quality control substance was added to the sample, and then, real‐time RT‐PCR was performed. Samples with negative test results and the corresponding data were analyzed; a quality control chart was created and examined.

Results

Data analysis and the quality control charts indicated that SARS‐CoV‐2 could be reliably detected using real‐time RT‐PCR, even when different nucleic acid extraction methods were used or when different technicians were employed.

Conclusion

With the use of quality control substances, it is possible to achieve quality control throughout the process—from nucleic acid extraction to nucleic acid detection—even upon using varying extraction methods. Further, generating quality control charts would guarantee the stable detection of SARS‐CoV‐2.