Biology subjects

Ueki, Y.

Publications and source records attributed to Ueki, Y..

4 recordsLinked to original sources

bioRxiv2023

The defects of the hippocampal ripples and theta rhythm in depression, and the effects of physical exercise on their amelioration.

Accumulated evidence demonstrate that environmental stress affects the hippocampus, functioning in cognition and sociality, and causes various depressive symptoms. In addition, recent findings showed that environmental stress influenced the hippocampal activity correlated with neuroinflammation, and impaired the hippocampal sharp wave ripples (SWRs), pattens of spike sequences, and the theta rhythms, a strong oscillation observed in the hippocampus. The involvement of the electrophysiological alterations in the etiology of depression has not been appreciated especially in the hippocampus. Furthermore, the pathological markers associated with such alterations have not been identified. In the present study, therefore, the impairment of the SWRs and the theta rhythms in the hippocampus of the restraint stress-induced depression model of mice was analyzed. In the model mice the hippocampal SWRs and theta rhythms were impaired in depression, while physical exercise significantly reverted them. As previously reported, chronic stress induced inflammation in the affected hippocampus in parallel with defects of adult neurogenesis, on the other hand physical exercise ameliorated those pathological conditions of the bran in depression. In conclusion, this study demonstrated the implications of impairment of the hippocampal SWRs and theta rhythms in the etiology of depression and their usefulness as diagnostic markers of depression.

neuroscience↗

bioRxiv2021

OC_Finder: A deep learning-based software for osteoclast segmentation, counting, and classification

Osteoclasts are multinucleated cells that exclusively resorb bone matrix proteins and minerals on the bone surface. They differentiate from monocyte/macrophage-lineage cells in the presence of osteoclastogenic cytokines such as the receptor activator of nuclear factor-{kappa}B ligand (RANKL) and are stained positive for tartrate-resistant acid phosphatase (TRAP). In vitro, osteoclast formation assays are commonly used to assess the capacity of osteoclast precursor cells for differentiating into osteoclasts wherein the number of TRAP-positive multinucleated cells are counted as osteoclasts. Osteoclasts are manually identified on cell culture dishes by human eyes, which is a labor-intensive process. Moreover, the manual procedure is not objective and result in lack of reproducibility. To accelerate the process and reduce the workload for counting the number of osteoclasts, we developed OC_Finder, a fully automated system for identifying osteoclasts in microscopic images. OC_Finder consists of segmentation and classification steps. OC_Finder detected osteoclasts differentiated from wild-type and Sh3bp2KI/+ precursor cells at a 99.4% accuracy for segmentation and at a 98.1% accuracy for classification. The number of osteoclasts classified by OC_Finder was at the same accuracy level with manual counting by a human expert. Together, successful development of OC_Finder suggests that deep learning is a useful tool to perform prompt and accurate unbiased classification and detection of specific cell types in microscopic images.

bioinformatics↗

bioRxiv2020

A highly conserved binding pocket on PP2A-B56 is required for shugoshin binding and cohesion protection

The shugoshin proteins are universal protectors of centromeric cohesin during mitosis and meiosis. The binding of human Sgo1 to the PP2A-B56 phosphatase through a coiled coil (CC) region is believed to mediate cohesion protection during mitosis. Here we undertook a structure function analysis of the PP2A-B56-Sgo1 complex, revealing unanticipated aspects of complex formation and function. We establish that a highly conserved pocket of the B56 regulatory subunit is required for Sgo1 binding and cohesion protection. Consistent with this, we show that Sgo1 blocks the binding of PP2A-B56 substrates containing a canonical B56 binding motif. Surprisingly, we identify B56 and Sgo1 mutants that prevent complex formation yet support cohesion protection and normal mitotic progression. This suggests that Sgo1 and PP2A-B56 have cohesion protection activity independently of complex formation. Collectively our work provides important insight into cohesion protection during mitosis.

cell biology↗

bioRxiv2020

Visuospatial n-back test for early detection of mild cognitive impairment in patients with Parkinsons Disease : an fMRI study

BackgroundCognitive impairment is a common symptom in the patients with Parkinsons disease (PD). In delineating a therapeutic plan, the early diagnosis of mild cognitive impairment in PD (PD-MCI) is important. Patients with PD-MCI have severe impairment in frontal executive function and/or visuospatial recognition. However, the clinical assessment of these functions is not routinely performed. MethodIn this study, we aimed to clarify the advantage of visuospatial version of the n-back test as a tool for the early detection of neuropsychological change in the patients with PD-MCI. The score of 0-back test reflects visuospatial recognition, and the scores of 1-back and 2-back reflect visuospatial working memory. PD-MCI was classified according to the criteria provided by the Movement Disorder Society Task Force for mild cognitive impairment in PD. We recruited 13 patients with PD-MCI, and 15 patients with cognitive normal PD. Using functional MRI (fMRI), we also aimed to clarify the specific brain regions associated with the impairment of visuospatial working memory. ResultWe demonstrated that the correct answer rate of patients with PD-MCI was lower in the 2-back test than patients with PD-CN. However, we did not find statistical difference in the 0-back test. These results indicate the preservation of visuospatial recognition and the impairment of visuospatial working memory in the patients with PD-MCI. We revealed the reduced activation within the middle frontal gyrus (MFG) and the inferior parietal lobule (IPL) during the 2-back test in the patients with PD-MCI. It may be associated with the severity of cortico-striatal dysfunction in the dopaminergic neural network which is associated with Lewy body pathology. ConclusionThe visuospatial n-back test has advantages for use in rapid and early detection of impaired visual recognition and working memory. The combination of functional neuroimaging and neuropsychological tests may provide markers for the increased risk of dementia before the development of an irreversible disease-specific pathology.

neuroscience↗