Biology subjects

Park, G.-S.

Publications and source records attributed to Park, G.-S..

5 recordsLinked to original sources

bioRxiv2023

Anti-muscle Atrophy Effects of Lactobacillus reuteri ATG-F4 and Its Impact on Intestinal Microbiota and Metabolites: Implications for Prophylaxis and Therapy

Lactobacillus reuteri ATG-F4, human gut-derived bacteria, was orally administrated in a model of hindlimb immobilization and confirmed the muscular performance, muscle mass and mechanism on anti-atrophy study. Concomitantly, the changes in the intestinal flora, the metabolites and cytokines were investigated. In the stapled immobilization mice model, ATG- F4 treated group had significantly increased muscle mass, myofiber size, running time to be exhausted and grip strength. The cytokine levels in serum and muscle tissues were reduced by ATG-F4 treatment. Furthermore, the phosphorylation of proteins involved in muscle synthesis such as mTOR, p70S6K, rpS6 and 4E-BP1 increased and MuRF1 related to muscle atrophy factor reduced in the TA and GA muscles. ATG-F4 treatment changed the ratio of main intestinal microflora by increasing the family Muribaculaceae (phylum Bacteroidetes) and decreasing the family Lachnospiraceae (phylum Firmicutes) and Lactobacillaceae (phylum Firmicutes). Also, the level of short chain fatty acids (SCFAs) including butyric acid and acetic acid in the serum of ATG-F4 group were increased. These results suggest that L. reuteri ATG- F4 can inhibit muscle atrophy and it is associated with the microbiota and its metabolites with the anti-inflammation effect. ATG-F4 may be a potential prophylactic or therapeutic composition for muscle atrophy.

physiology↗

bioRxiv2022

Development and Evaluation of RT-LAMP Assays to Identify Variants of SARS-CoV-2

Emergence of new variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) during current pandemic of Coronavirus Disease 2019 (COVID-19) and several waves of infections by some of variants emphasized the importance of continuous surveillance. While genomic surveillance through whole genome sequencing is performed as a standard method, identification of known variants through mutation-targeting molecular diagnosis such as qRT-PCR is also useful for timely investigation. However, there are limited studies regarding the concurrent detection and identification of SARS-CoV-2 variants through a LAMP-based method. In this study, we developed and evaluated RT-LAMP assays to detect characteristic deletions of SARS-CoV-2 variants. In addition, we evaluated a fluorescent probe mediated method for identification of single nucleotide substitution by RT-LAMP. Finally, we discussed restrictions and perspectives regarding pathogen screening and surveillance of variants by RT-LAMP based on our observations.

microbiology↗

bioRxiv2020

Robust and sensitive detection of SARS-CoV-2 using PCR based methods

The World Health Organization (WHO) has declared the Coronavirus disease 2019 (COVID-19) as an international health emergency. Current diagnostic tests are based on the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method, the gold standard test that involves the amplification of viral RNA. However, the RT-qPCR assay has limitations in terms of sensitivity and quantification. In this study, we tested both qPCR and droplet digital PCR (ddPCR) to detect low amounts of viral RNA. The cycle threshold (CT) of viral RNA by RT-PCR significantly varied according to the sequence of primer and probe sets with in vitro transcript (IVT) RNA or viral RNA as templates, whereas the copy number of viral RNA by ddPCR was effectively quantified with IVT RNA, cultured viral RNA, and RNA from clinical samples. Furthermore, the clinical samples were assayed via both methods, and the sensitivity of the ddPCR was determined to be significantly higher than RT-qPCR. These findings suggest that ddPCR could be used as a highly sensitive and compatible diagnostic method for viral RNA detection.

microbiology↗

bioRxiv2020

Development of Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) Assays Targeting SARS-CoV-2

Epidemics of Coronavirus Disease 2019 (COVID-19) now have more than 100,000 confirmed cases worldwide. Diagnosis of COVID-19 is currently performed by RT-qPCR methods, but the capacity of RT-qPCR methods is limited by its requirement of high-level facilities and instruments. Here, we developed and evaluated RT-LAMP assays to detect genomic RNA of SARS-CoV-2, the causative virus of COVID-19. RT-LAMP assays in this study can detect as low as 100 copies of SARS-CoV-2 RNA. Cross-reactivity of RT-LAMP assays to other human Coronaviruses was not observed. We also adapted a colorimetric detection method for our RT-LAMP assay so that the tests potentially performed in higher throughput.

microbiology↗

bioRxiv2020

Comparative analysis of primer-probe sets for the laboratory confirmation of SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is newly emerging human infectious diseases, which is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, also previously known as 2019-nCoV). Within two months of the outbreak, more than 80,000 cases of COVID-19 have been confirmed worldwide. Since the human to human transmission occurred easily and the human infection is rapidly increasing, the sensitive and early diagnosis is essential to prevent the global outbreak. Recently, World Health Organization (WHO) announced various primer and probe sets for SARS-CoV-2 previously developed in China, Germany, Hong Kong, Japan, Thailand, and USA. In this study, we compared the ability to detect SARS-CoV-2 RNA among the seven primer-probe sets for N gene and the three primer-probe sets for Orf1 gene. The result of the comparative analysis represented that the 2019-nCoV_N2, N3 of USA and the ORF1ab of China are the most sensitive primer-probe sets for N and Orf1 genes, respectively. Therefore, the appropriate combination from ORF1ab (China), 2019-nCoV_N2, N3 (USA), and NIID_2019-nCOV_N (Japan) sets should be selected for the sensitive and reliable laboratory confirmation of SARS-CoV-2.

microbiology↗