ARTICLE | doi:10.20944/preprints202103.0374.v1
Subject: Life Sciences, Biochemistry Keywords: cfDNA; next generation sequencing; full marathon; exercise; physiology
Online: 15 March 2021 (11:52:33 CET)
Plasma cell-free DNA (cfDNA) is frequently analyzed using liquid biopsy to investigate cancer markers. Accordingly, we hypothesized this concept could be applied to the field of exercise physiology. Here, we aimed to identify specific cfDNA (spcfDNA) sequences in the plasma of non-treated human participants using next generation sequencing (NGS) and to clearly define the dynamics regarding the amounts of spcfDNA-fragments upon extreme exercise, such as running a full marathon. NGS analysis was performed using cfDNA of pooled plasma collected from non-treated participants. We confirmed the TaqMan-qPCR assay had a high sensitivity and found the spcfDNA sequence abundance was 16,600-fold higher than a normal genomic region. We then used the TaqMan-qPCR assay to investigate the dynamics of the levels of spcfDNA-fragments upon running a full marathon. Quantities of the spcfDNA fragments were significantly increased post marathon. Furthermore, the amounts of spcfDNA fragments strongly correlated with the numbers of white blood cells and plasma myoglobin concentrations. These results suggest the spcfDNA fragments identified in this study were highly sensitive response markers to extreme physical stress. The findings of this study may provide new insights into exercise physiology and genome biology on the human.
ARTICLE | doi:10.20944/preprints202002.0106.v1
Subject: Life Sciences, Biophysics Keywords: osteoarthritis; synovitis; articular cartilage; microfocus X-ray CT; 3D analysis
Online: 9 February 2020 (15:49:10 CET)
The aim of this study was to clarify degradation characteristics in each tissue of the knee complex of a medial meniscectomy (MMx)-induced knee osteoarthritis (KOA) animal model using classical methods and a new comprehensive evaluation method called contrast-enhanced X-ray micro-computed tomography (CEX-μCT), which was developed in the study. Surgical MMx was performed in the right knee joints of five male Wistar rats to induce KOA. At 4 wk post-surgery, the synovitis was evaluated using qPCR. Degradations of the articular cartilage of the tibial plateau were evaluated using classical methods and CEX-μCT. Evaluation of the synovitis demonstrated significantly increased expression levels of inflammation-associated marker genes in MMx-treated knees compared to that in sham-treated knees. Evaluation of the articular cartilage using classical methods showed that MMx fully induced degradation of the cartilage. Evaluation using CEX-μCT showed that local areas of the medial cartilage of the tibial plateau were significantly reduced in MMx-treated knees compared to that in sham-treated knees. On the other hand, total cartilage volumes were significantly increased in MMx-treated knees. Based on the findings of this study, the researchers in KOA research could be helped to select an optimal KOA model to discover new drugs.
ARTICLE | doi:10.20944/preprints202005.0366.v1
Subject: Life Sciences, Genetics Keywords: gene doping; gene therapy; in vivo transfection; in vivo imaging
Online: 23 May 2020 (10:11:31 CEST)
The World Anti-Doping Agency has prohibited gene doping in the context of progress in gene therapy. There is a risk that the artificial regulation of genes using plasmids could be applied for gene doping. However, no gold standard method to detect this has been established. Here, we aimed to develop a method to detect multiple transgene fragments as proof of gene doping. First, gene delivery model mice as a mimic of gene doping were created by injecting firefly luciferase plasmid with polyethylenimine (PEI) into the abdominal cavity. The results confirmed successful establishment of the model, with sufficient luminescence upon in vivo imaging. Next, multiple transgene fragments in the model were detected in plasma cell-free (cf)DNA, blood-cell-fraction DNA, and stool DNA using the TaqMan-qPCR assay, with the highest levels in plasma cfDNA. Using just a single drop of whole blood from the model, we also attempted long-term detection. The results showed that multiple transgene fragments were detected until 11 days. These findings indicate that the combination of plasma cfDNA or just one drop of whole blood with TaqMan-qPCR assay is feasible to detect plasmid-PEI-based gene doping. Our findings could accelerate the development of methods for detecting gene doping in humans.