Biology subjects

Miyashita, K.

Publications and source records attributed to Miyashita, K..

3 recordsLinked to original sources

bioRxiv2022

Plap-1/Aspn lineage tracing and single-cell transcriptomics reveals cellular dynamics in the periodontal ligament

Periodontal tissue supports teeth in the alveolar bone socket via fibrous attachment of the periodontal ligament (PDL). The PDL contains periodontal fibroblasts and stem/progenitor cells, collectively known as PDL cells (PDLCs), on top of osteoblasts and cementoblasts on the surface of alveolar bone and cementum, respectively. However, the characteristics and lineage hierarchy of each cell type remain poorly defined. This study identified periodontal ligament associated Protein-1 (Plap-1/Aspn) as a PDL-specific extracellular matrix. We generated knock-in mice expressing CreERT2 and GFP specifically in Plap-1-positive PDLCs. Genetic lineage tracing confirmed the long-standing hypothesis that PDLCs differentiated into osteoblasts and cementoblasts. A PDL single-cell atlas defined cementoblasts and osteoblasts as Plap-1-Ibsp+Sparcl1+ and Plap-1-Ibsp+Col11a2+, respectively. Other populations such as Nes+ mural cells, S100B+ Schwann cells, and other non-stromal cells were also identified. RNA velocity analysis suggested that Plap-1highLy6a+ cell population was the source of PDLCs. Lineage tracing of Plap-1+ PDLCs during the periodontal injury model showed periodontal tissue regeneration by PDLCs. Our study defines diverse cell populations in PDL and clarifies the role of PDLCs in periodontal tissue homeostasis and repair.

developmental biology↗

bioRxiv2021

Biomechanical characteristics of scapula and glenohumeral movements during pitching motion in injury-prone college baseball pitchers

Coordination of glenohumeral and scapular movements plays an important role in the injury prevention of baseball pitchers. However, there is no objective data establishing the direct relationship between pitching injuries and associated glenohumeral and scapular movements. Therefore, the objectives of the present study were to demonstrate biomechanical differences in scapular and glenohumeral movements during pitching between injury-prone pitchers and healthy college baseball pitchers. Thirty collegiate baseball pitchers were classified into two groups according to their injury status: injury-prone group (N=15, 20.7{+/-}1.4 years, 180.1{+/-}6.5 cm, 78.9{+/-}5.4 kg) and control group (N=15, 20.9{+/-}1.1 years, 177.1{+/-}6.6 cm, 72.3{+/-}6.7 kg). We obtained the pitching motion data using the three-dimensional motion analysis technique with four high-speed cameras. The horizontal abduction angles of the glenohumeral joint during cocking and acceleration phases were significantly greater in injury-prone pitchers [19.0{degrees} (95% CI: 14.4-23.6) at foot contact, -4.0{degrees} (95% CI: -7.7 to -0.2) at maximum external rotation (MER), and -0.3{degrees} (95% CI: -4.8 to -4.2) at ball release] than in healthy controls [11.7 {degrees}(95%CI:7.1 to 16.3) at foot contact, -10.0{degrees}(95%CI: -13.7 to -6.3) at MER, and -6.9{degrees}(95%CI: -11.4 to -2.4)](p<0.01). In addition, the external rotation angle (ER) of the scapula at MER was significantly greater in the injury-prone group [-0.1{degrees} (95% CI: -5.0 to 4.8)] than in the control group [-12.3{degrees} (95% CI: -17.2 to -7.4)] (p<0.01), but there was no difference in the scapular ER during foot contact between the two groups. These results suggests that injury-prone pitchers have less internal rotation of the scapula and more horizontal abduction of the glenohumeral joint during cocking and acceleration phases. Therefore, sports medicine practitioners may need to pay more attention to coordination of scapular and glenohumeral movements during the cocking and acceleration phases of pitching for prevention of shoulder injuries.

physiology↗

bioRxiv2018

Estimating fish population abundance by integrating quantitative data on environmental DNA and hydrodynamic modelling

We propose a general framework of abundance estimation based on spatially replicated quantitative measurements of environmental DNA in which production, transport, and degradation of DNA are explicitly accounted for. Application to a Japanese jack mackerel (Trachurus japonicus) population in Maizuru Bay revealed that the method gives an estimate of population abundance comparable to that of a quantitative echo sounder method. These findings indicate the ability of environmental DNA to reliably reflect population abundance of aquatic macroorganisms and may o[ff]er a new avenue for population monitoring based on the fast, cost-e[ff]ective, and non-invasive sampling of genetic information.

ecology↗