Clostridium sordellii lethal toxin (TcsL) belongs to the family of clostridial glucosylating toxins. TcsL exhibits glucosyltransferase activity to inactivate Rho and Ras proteins. On cultured cells, TcsL causes actin reorganization ("cytopathic effect") and apoptotic cell death ("cytotoxic effect"). This study is based on the concept that the cytotoxic effects of TcsL depend on the glucosylation of critical substrate proteins rather than on the glucosyltransferase activity per se. The cytotoxic effects of TcsL depend on the glucosyltransferase activity of TcsL, as neither chemically inactivated TcsL nor a glucosyltransferase-deficient mutant version of TcsL caused it. The TcsL homologous toxin B from Clostridium difficile serotype F strain 1470 (TcdBF) also failed to cause cytotoxic effects. Correlation of the toxins' respective protein substrate specificities highlighted (H/K/N)Ras as critical substrate proteins for the cytotoxic effects. (H/K/N)Ras are critical upstream regulators of phosphatidylinositide 3'-OH kinase (PI3K)/Akt survival signaling. Tauroursodeoxycholic acid (TUDCA) classified to activate PI3K/Akt signaling downstream of apoptosis-inducing stimuli prevented the cytotoxic effects of TcsL. In conclusion, (H/K/N)Ras glucosylation and subsequent inhibition of PI3K/Akt signaling are critical for the cytotoxic effects of TcsL.
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Sci Rep
December 2024
School of Medicine, Yichun University, Yichun, 336000, China.
Iron oxide nanoparticles (IONPs) have the potential to be utilized in a multitude of fields, including biomedicine. Consequently, the potential health risks associated with their use must be carefully considered. Most biosafety evaluations of IONPs have focused on examining the impact of the material's distinctive physicochemical attributes.
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December 2024
Department of Biochemistry, Faculty of Science, Mahidol University, 272 Rama VI Road, Thung Phayathai, Ratchathewi, Bangkok, 10400, Thailand.
Wnt signaling is a critical pathway implicated in cancer development, with Frizzled proteins, particularly FZD10, playing key roles in tumorigenesis and recurrence. This study focuses on the potential of repurposed FDA-approved drugs targeting FZD10 as a therapeutic strategy for nasopharyngeal carcinoma (NPC). The tertiary structure of human FZD10 was constructed using homology modeling, validated by Ramachandran plot and ProQ analysis.
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December 2024
Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
Despite decades of improvements in cytotoxic therapy, the current standard of care for locally advanced pancreatic cancer (LAPC) provides, on average, only a few months of survival benefit. Stereotactic Body Radiation Therapy (SBRT), a technique that accurately delivers high doses of radiation to tumors in fewer fractions, has emerged as a promising therapy to improve local control of LAPC; however, its effects on the tumor microenvironment and hypoxia remain poorly understood. To explore how SBRT affects pancreatic tumors, we combined an orthotopic mouse model of pancreatic cancer with an intravital microscopy platform to visualize changes to the in vivo tumor microenvironment in real-time.
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December 2024
Department of Urology, Urological Science Institute, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-gu, Seoul, 03722, South Korea.
Carbon dots (CDs) are versatile nanomaterials that are considered ideal for application in bioimaging, drug delivery, sensing, and optoelectronics owing to their excellent photoluminescence, biocompatibility, and chemical stability features. Nitrogen doping enhances the fluorescence of CDs, alters their electronic properties, and improves their functional versatility. N-doped CDs can be synthesized via solvothermal treatment of carbon sources with nitrogen-rich precursors; however, systematic investigations of their synthesis mechanisms have been rarely reported.
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December 2024
Immunobiology for Aquaculture Group, Department of Cell Biology and Histology, Faculty of Biology, Campus of International Excellence, Campus Mare Nostrum, University of Murcia, Murcia, Spain.
The aim of the study was to investigate the potential preventive use of short-chain fatty acids (SCFAs) to modulate inflammatory responses in gilthead seabream (Sparus aurata) skin. Initially, in vitro experiments were conducted to evaluate the effects of various concentrations of butyric acid, acetic acid and propionic acid, as well as their combination, on the cytotoxicity and cell viability of three different cell lines. The results determined the safe concentration of SCFAs, which was then used for an in vivo study.
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