Regular graphs to induce even periodic Grover walks

The interest of this paper is a characterization of graphs that induce periodic Grover walks with given periods. In previous studies, Yoshie has shown that the only graphs that induce odd periodic Grover walks are cycle graphs. However, this problem is largely unsolved for even periods. In this study, we show that regular graphs that induce $2l$-periodic Grover walks are also cycle graphs in most cases, where $l$ is an odd integer. The proof uses Galois theory.Comment: 16 page

Effect of Angiotensin II on Chondrocyte Degeneration and Protection via Differential Usage of Angiotensin II Receptors

The renin-angiotensin system (RAS) controls not only systemic functions, such as blood pressure, but also local tissue-specific events. Previous studies have shown that angiotensin II receptor type 1 (AT(1)R) and type 2 (AT(2)R), two RAS components, are expressed in chondrocytes. However, the angiotensin II (ANG II) effects exerted through these receptors on chondrocyte metabolism are not fully understood. In this study, we investigated the effects of ANG II and AT(1)R blockade on chondrocyte proliferation and differentiation. Firstly, we observed that ANG II significantly suppressed cell proliferation and glycosaminoglycan content in rat chondrocytic RCS cells. Additionally, ANG II decreased CCN2, which is an anabolic factor for chondrocytes, via increased MMP9. In Agtr1a-deficient RCS cells generated by the CRISPR-Cas9 system, Ccn2 and Aggrecan (Acan) expression increased. Losartan, an AT(1)R antagonist, blocked the ANG II-induced decrease in CCN2 production and Acan expression in RCS cells. These findings suggest that AT(1)R blockade reduces ANG II-induced chondrocyte degeneration. Interestingly, AT(1)R-positive cells, which were localized on the surface of the articular cartilage of 7-month-old mice expanded throughout the articular cartilage with aging. These findings suggest that ANG II regulates age-related cartilage degeneration through the ANG II-AT(1)R axis

The critical balance between dopamine D2 receptor and RGS for the sensitive detection of a transient decay in dopamine signal

In behavioral learning, reward-related events are encoded into phasic dopamine (DA) signals in the brain. In particular, unexpected reward omission leads to a phasic decrease in DA (DA dip) in the striatum, which triggers long-term potentiation (LTP) in DA D2 receptor (D2R)-expressing spiny-projection neurons (D2 SPNs). While this LTP is required for reward discrimination, it is unclear how such a short DA-dip signal (0.5–2 s) is transferred through intracellular signaling to the coincidence detector, adenylate cyclase (AC). In the present study, we built a computational model of D2 signaling to determine conditions for the DA-dip detection. The DA dip can be detected only if the basal DA signal sufficiently inhibits AC, and the DA-dip signal sufficiently disinhibits AC. We found that those two requirements were simultaneously satisfied only if two key molecules, D2R and regulators of G protein signaling (RGS) were balanced within a certain range; this balance has indeed been observed in experimental studies. We also found that high level of RGS was required for the detection of a 0.5-s short DA dip, and the analytical solutions for these requirements confirmed their universality. The imbalance between D2R and RGS is associated with schizophrenia and DYT1 dystonia, both of which are accompanied by abnormal striatal LTP. Our simulations suggest that D2 SPNs in patients with schizophrenia and DYT1 dystonia cannot detect short DA dips. We finally discussed that such psychiatric and movement disorders can be understood in terms of the imbalance between D2R and RGS

Treatment effects on neurometabolite levels in schizophrenia: A meta-analysis dataset of proton magnetic resonance spectroscopy

This article describes a dataset for a meta-analysis that aimed to investigate the effects of treatment on the neurometabolite status in patients with schizophrenia (DOI of original article: https://doi.org/10.1016/j.schres.2020.03.069 [1]). The data search was performed with MEDLINE, Embase, and PsycINFO. The neurometabolites investigated include glutamate, glutamine, glutamate + glutamine, gamma-aminobutyric acid, N-acetylaspartate, and myo-inositol, and the regions of interest (ROIs) include the frontal cortex, temporal cortex, parieto-occipital cortex, thalamus, basal ganglia, and hippocampus. The meta-analysis was conducted with a random-effects model, and the use of the standardized mean difference method between pre- and post-treatment of subjects for neurometabolites in each ROI of three patient groups or more. The dataset covers raw data of 39 patient groups (773 patients with schizophrenia at follow-up) with neurometabolite levels measured by magnetic resonance spectroscopy both before and after treatment. Furthermore, it contains details of clinical characteristics and treatment types for each group. Therefore, the data would be useful for a reinvestigation of treatment effects on the neurometabolite status from diverse points of view, as well as for the development of future treatment strategies for psychiatric diseases

Regulation of cellular communication network factor 2 (CCN2) in breast cancer cells via the cell-type dependent interplay between CCN2 and glycolysis

Objectives: Anti-osteoclastic treatments for breast cancer occasionally cause medication-related osteonecrosis of the jaw. Moreover, elevated glycolytic activity, which is known as the Warburg effect, is usually observed in these breast cancer cells. Previously, we found that cellular communication network factor 2 (CCN2) production and glycolysis enhanced each other in chondrocytes. Here, we evaluated the interplay between CCN2 and glycolysis in breast cancer cells, as we suspected a possible involvement of CCN2 in the Warburg effect in highly invasive breast cancer cells. Methods: Two human breast cancer cell lines with a distinct phenotype were used. Glycolysis was inhibited by using 2 distinct compounds, and gene silencing was performed using siRNA. Glycolysis and the expression of relevant genes were monitored via colorimetric assays and quantitative RT-PCR, respectively. Results: Although CCN2 expression was almost completely silenced when treating invasive breast cancer cells with a siRNA cocktail against CCN2, glycolytic activity was not affected. Notably, the expression of glycolytic enzyme genes, which was repressed by CCN2 deficiency in chondrocytes, tended to increase upon CCN2 silencing in breast cancer cells. Inhibition of glycolysis, which resulted in the repression of CCN2 expression in chondrocytic cells, did not alter or strongly enhanced CCN2 expression in the invasive and non-invasive breast cancer cells, respectively. Conclusions: High CCN2 expression levels play a critical role in the invasion and metastasis of breast cancer. Thus, a collapse in the intrinsic repressive machinery of CCN2 due to glycolysis may induce the acquisition of an invasive phenotype in breast cancer cells

Selective sorption of oxygen and nitrous oxide by an electron donor-incorporated flexible coordination network

Incorporating strong electron donor functionality into flexible coordination networks is intriguing for sorption applications due to a built-in mechanism for electron-withdrawing guests. Here we report a 2D flexible porous coordination network, [Ni₂(4, 4′-bipyridine)(VTTF)₂]n(1) (where H₂VTTF = 2, 2′-[1, 2-bis(4-benzoic acid)-1, 2ethanediylidene]bis-1, 3-benzodithiole), which exhibits large structural deformation from the as-synthesized or open phase (1α) into the closed phase (1β) after guest removal, as demonstrated by X-ray and electron diffraction. Interestingly, upon exposure to electron-withdrawing species, 1β reversibly undergoes guest accommodation transitions; 1α⊃O₂ (90 K) and 1α⊃N₂O (185 K). Moreover, the 1β phase showed exclusive O₂ sorption over other gases (N₂, Ar, and CO) at 120 K. The phase transformations between the 1α and 1β phases under these gases were carefully investigated by in-situ X-ray diffraction, in-situ spectroscopic studies, and DFT calculations, validating that the unusual sorption was attributed to the combination of flexible frameworks and VTTF (electron-donor) that induces strong interactions with electron-withdrawing species