Dynamics of Wnt/β-catenin reporter activity throughout whole life in a naturally short-lived vertebrate

Ogamino S., Yamamichi M., Sato K., et al. Dynamics of Wnt/β-catenin reporter activity throughout whole life in a naturally short-lived vertebrate. npj Aging 10, 23 (2024); https://doi.org/10.1038/s41514-024-00149-1.Wnt/β-catenin signaling plays a major role in regulation of embryogenesis, organogenesis, and adult tissue homeostasis and regeneration. However, the roles played by Wnt/β-catenin and the spatiotemporal regulation of its activity throughout life, including during aging, are not fully understood. To address these issues, we introduced a Wnt/β-catenin signaling sensitive reporter into African turquoise killifish (Nothobranchius furzeri), a naturally ultra-short-lived fish that allows for the analysis of its whole life within a short period of time. Using this reporter killifish, we unraveled the previously unidentified dynamics of Wnt/β-catenin signaling during development and aging. Using the reporter strain, we detected Wnt/β-catenin activity in actively developing tissues as reported in previous reports, but also observed activation and attenuation of Wnt/β-catenin activity during embryonic reaggregation and diapause, respectively. During the aging process, the reporter was activated in the choroidal layer and liver, but its expression decreased in the kidneys. In addition, the reporter also revealed that aging disrupts the spatial regulation and intensity control of Wnt/β-catenin activity seen during fin regeneration, which interferes with precise regeneration. Thus, the employed reporter killifish is a highly useful model for investigating the dynamics of Wnt/β-catenin signaling during both the developmental and aging process

Pentosidine Accumulation in Human Oocytes and Their Correlation to Age-Related Apoptosis

Age-related atresia of ovarian follicles is characterized by apoptosis of the constituent cells. Recent studies have indicated that dysfunction of the proteasome and endoplasmic reticulum and subsequent apoptosis in the presence of oxidative stress have relevance to aging. The aim of this study was to assess the involvement of these processes in age-related follicular atresia. Formalin-fixed, paraffin-embedded sections of ovaries obtained at surgery from 74 women (age: 21–54 y) were examined with the terminal deoxynucleotidyl transferase-mediated, dUTP-biotin nick-end labeling (TUNEL) method and an immunohistochemical technique. Primary antibodies used in immunohistochemistry were against pentosidine, ubiquitin and caspase 12. Histological localization of these substances in oocytes was observed by light microscopy, and labeling indices of these cells were evaluated by regression analysis. Positive signals for pentosidine, ubiquitin, caspase 12, and TUNEL were detectable in oocytes of the primordial, primary and their atretic follicles. Regression analysis revealed an age-related increase in the labeling indices for pentosidine, ubiquitin, caspase 12, and TUNEL. These results suggest that pentosidine accumulation in human oocytes is related to apoptosis and increases with age. Further studies will be necessary to clarify the involvement of pentosidine accumulation, proteasome inhibition, and endoplasmic reticulum stress in age-related apoptosis of oocytes in human ovaries

Structural basis of Sec-independent membrane protein insertion by YidC

[プレスリリース]バイオサイエンス研究科膜分子複合機能学研究室の塚崎智也准教授らの研究グループが、タンパク質を細胞膜に組み込むメカニズムを解明しました（2014/04/17）Newly synthesized membrane proteins must be accurately inserted into the membrane, folded and assembled for proper functioning. The protein YidC inserts its substrates into the membrane, thereby facilitating membrane protein assembly in bacteria; the homologous proteins Oxa1 and Alb3 have the same function in mitochondria and chloroplasts, respectively1, 2. In the bacterial cytoplasmic membrane, YidC functions as an independent insertase and a membrane chaperone in cooperation with the translocon SecYEG3, 4, 5. Here we present the crystal structure of YidC from Bacillus halodurans, at 2.4 Å resolution. The structure reveals a novel fold, in which five conserved transmembrane helices form a positively charged hydrophilic groove that is open towards both the lipid bilayer and the cytoplasm but closed on the extracellular side. Structure-based in vivo analyses reveal that a conserved arginine residue in the groove is important for the insertion of membrane proteins by YidC. We propose an insertion mechanism for single-spanning membrane proteins, in which the hydrophilic environment generated by the groove recruits the extracellular regions of substrates into the low-dielectric environment of the membrane

Four microlensing giant planets detected through signals produced by minor-image perturbations

Funding: Work by C.H. was supported by the grants of National Research Foundation of Korea (2019R1A2C2085. This research was supported by the Korea Astronomy and Space Science Institute under the R&D program (Project No. 2023-1-832-03) supervised by the Ministry of Science and ICT. The MOA project is supported by JSPS KAKENHI Grant Number JP24253004, JP26247023, JP23340064, JP15H00781, JP16H06287, JP17H02871 and JP22H00153. J.C.Y., I.G.S., and S.J.C. acknowledge support from NSF Grant No. AST-2108414. Y.S. acknowledges support from NSF Grant No. 2020740. C.R. was supported by the Research fellowship of the Alexander von Humboldt Foundation. This work was authored by employees of Caltech/IPAC under Contract No. 80GSFC21R0032 with the National Aeronautics and Space Administration. V.B. is supported by PRIN 2022 CUP D53D23002590006. R.F.J. acknowledges support for this project provided by ANID’s Millennium Science Initiative through grant ICN12_009, awarded to the Millennium Institute of Astrophysics (MAS), and by ANID’s Basal project FB210003. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 101004719 (OPTICON - RadioNet Pilot). This work is supported by the Polish MNiSW grant DIR/WK/2018/12.Aims. We investigated the nature of the anomalies appearing in four microlensing events KMT-2020-BLG-0757, KMT-2022-BLG-0732, KMT-2022-BLG-1787, and KMT-2022-BLG-1852. The light curves of these events commonly exhibit initial bumps followed by subsequent troughs that extend across a substantial portion of the light curves. Methods. We performed thorough modeling of the anomalies to elucidate their characteristics. Despite their prolonged durations, which differ from the usual brief anomalies observed in typical planetary events, our analysis revealed that each anomaly in these events originated from a planetary companion located within the Einstein ring of the primary star. It was found that the initial bump arouse when the source star crossed one of the planetary caustics, while the subsequent trough feature occurred as the source traversed the region of minor image perturbations lying between the pair of planetary caustics. Results. The estimated masses of the host and planet, their mass ratios, and the distance to the discovered planetary systems are (Mhost/M⊙, Mplanet/MJ, q/10−3, DL/kpc) = (0.58−0.30+0.33, 10.71−5.61+6.17, 17.61 ± 2.25, 6.67−1.30+0.93) for KMT-2020-BLG-0757, (0.53−0.31+0.31, 1.12−0.65+0.65, 2.01 ± 0.07, 6.66−1.84+1.19) for KMT-2022-BLG-0732, (0.42−0.23+0.32, 6.64−3.64+4.98, 15.07 ± 0.86, 7.55−1.30+0.89) for KMT-2022-BLG-1787, and (0.32−0.19+0.34, 4.98−2.94+5.42, 8.74 ± 0.49, 6.27−1.15+0.90) for KMT-2022-BLG-1852. These parameters indicate that all the planets are giants with masses exceeding the mass of Jupiter in our solar system and the hosts are low-mass stars with masses substantially less massive than the Sun.Peer reviewe

Direct Measurement of Intramolecular Electron Transfer in a Series of Artificial Photosynthesis Processes

We have directly determined the intramolecular electron transfer rate and revealed its mechanism in supramolecular complexes during CO2 photoreduction by time-resolved infrared spectroscopic measurements over a wide temporal range