Besides the well-recognized role of CD45 as a major player in TCR signaling, we and others have demonstrated that cross-linking of CD45 with mAbs can induce cell death in T lymphocytes. To investigate the role of CD45 phosphatase activity in apoptosis induction, we expressed either wild-type or phosphatase-dead CD45 molecules in a CD45-deficient BW5147 T cell line. We show here that the phosphatase activity of CD45 was not required for apoptosis triggering after cross-linking of the molecule. It is noteworthy that a revertant of the CD45-negative BW5147 cell line, expressing a truncated form of CD45 lacking most of the cytoplasmic domain, was also susceptible to CD45-mediated death. Moreover, we also demonstrate that leukocyte phosphatase-associated phosphoprotein expression is totally dispensable for CD45-mediated apoptosis to occur. Taken together, these results strongly suggest a role for the extracellular and/or the transmembrane portion of CD45 in apoptosis signaling, which contrasts with the previously reported functions for CD45 in T lymphocytes.
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http://dx.doi.org/10.4049/jimmunol.168.12.6084 | DOI Listing |
Ann Biomed Eng
January 2025
Department of Biomedical Engineering, Yildiz Technical University, Esenler, 34220, Istanbul, Türkiye.
Titanium (Ti)-based materials are favored for hard tissue applications, yet their bioinertness limits their success. This study hypothesizes that functionalizing Ti materials with chitosan nano/microspheres and calcitriol (VD) will enhance their bioactivity by improving cellular activities and mineralization. To test this, chitosan particles were applied uniformly onto Ti surfaces using electrophoretic deposition (EPD) at 20 V for 3 minutes.
View Article and Find Full Text PDFPlanta Med
January 2025
Instituto de Química, Departamento de Productos Naturales, Universidad Nacional Autónoma de México, Mexico City, Mexico.
An approach combining enzymatic inhibition and untargeted metabolomics through molecular networking was employed to search for human recombinant full-length protein tyrosine phosphatase 1B (PTP1 B) inhibitors from a collection of 66 mangrove-associated fungal taxa. This strategy prioritized two strains (IQ-1612, section , and IQ-1620, section ) for further studies. Chemical investigation of strain IQ-1612 resulted in the isolation of a new nonanolide derivative, roseoglobuloside A (1: ), along with two known metabolites (2: and 3: ), whereas strain IQ-1620 led to the isolation of four known naphtho-γ-pyrones and one known diketopiperazine (4: -8: ).
View Article and Find Full Text PDFJ Clin Invest
January 2025
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, United States of America.
Dysregulated eIF4E-dependent translation is a central driver of tumorigenesis and therapy resistance. eIF4E binding proteins (4E-BP1/2/3) are major negative regulators of eIF4E-dependent translation that are inactivated in tumors through inhibitory phosphorylation or downregulation. Previous studies have linked PP2A phosphatase(s) to activation of 4E-BP1.
View Article and Find Full Text PDFEndocrinol Diabetes Metab Case Rep
January 2025
Summary: Hypophosphatasia (HPP) is a genetic disorder due to pathological variants in ALPL, the gene encoding tissue-nonspecific alkaline phosphatase (ALP). HPP is typically associated with bone-related symptoms, such as bone deformity, fractures and bone pain in children, but can appear in adults with symptoms resembling arthritis. A 22-year-old male experienced repeated and severe sudden attacks of joint pain in the elbows and knees.
View Article and Find Full Text PDFUnlabelled: Asymmetric cell division is used by stem cells to create diverse cell types while self-renewing the stem cell population. Biased segregation of molecularly distinct centrosomes could provide a mechanism to maintain stem cell fate, induce cell differentiation or both. However, the molecular mechanisms generating molecular and functional asymmetric centrosomes remain incompletely understood.
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