Transforming growth factor-beta (TGF-beta) activity is controlled at many levels including the conversion of the latent secreted form to its active state. TGF-beta is often released as part of an inactive tripartite complex consisting of TGF-beta, the TGF-beta propeptide, and a molecule of latent TGF-beta binding protein (LTBP). The interaction of TGF-beta and its cleaved propeptide renders the growth factor latent, and the liberation of TGF-beta from this state is crucial for signaling. To examine the contribution of LTBP to TGF-beta function, we generated mice in which the cysteines that link the propeptide to LTBP were mutated to serines, thereby blocking covalent association. Tgfb1(C33S/C33S) mice had multiorgan inflammation, lack of skin Langerhans cells (LC), and a shortened lifespan, consistent with decreased TGF-beta1 levels. However, the inflammatory response and decreased lifespan were not as severe as observed with Tgfb1(-/-) animals. Tgfb1(C33S/C33S) mice exhibited decreased levels of active TGF-beta1, decreased TGF-beta signaling, and tumors of the stomach, rectum, and anus. These data suggest that the association of LTBP with the latent TGF-beta complex is important for proper TGF-beta1 function and that Tgfb1(C33S/C33S) mice are hypomorphs for active TGF-beta1. Moreover, although mechanisms exist to activate latent TGF-beta1 in the absence of LTBP, these mechanisms are not as efficient as those that use the latent complex containing LTBP.
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http://dx.doi.org/10.1073/pnas.0805411105 | DOI Listing |
Tissue Cell
December 2024
Department of Neurosurgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China. Electronic address:
Glioblastoma is considered the most malignant central nervous system tumor. This study aimed to investigate effects of latent transforming growth factor-β binding protein-2 (LTBP2) on glioblastoma growth and associated mechanisms. LTBP2 gene transcription in glioblastoma was determined using RT-PCR.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Department of Hematology, Rheumatology and Infectious Disease, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy (HAM) after a long latent period in a fraction of infected individuals. These HTLV-1-infected cells typically have phenotypes similar to that of CD4+T cells, but the cell status is not well understood. To extract the inherent information of HTLV-1-infected CD4+ cells, we integratively analyzed the ATAC-seq and RNA-seq data of the infected cells.
View Article and Find Full Text PDFMedicine (Baltimore)
December 2024
Xuzhou Clinical College of Xuzhou Medical University, Xuzhou Central Hospital, Xuzhou, China.
Rationale: The aim of this study is to investigate the de novo mutation and clinical features of latent transforming growth factor-beta-binding protein 3 (LTBP3) gene-associated geleophysic dysplasia 3, and possible mechanisms of action.
Patient Concerns: A nonconsanguineous couple was recruited for this study due to the presence of intrauterine growth restriction. The pregnant woman and her elder daughter presented with skeletal abnormalities with diabetes.
Sci Transl Med
December 2024
Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
Excessive deposition of fibrillar collagen in the interstitial extracellular matrix (ECM) of human lung tissue causes fibrosis, which can ultimately lead to organ failure. Despite our understanding of the molecular mechanisms underlying the disease, no cure for pulmonary fibrosis has yet been found. We screened a drug library and found that dextromethorphan (DXM), a cough expectorant, reduced the amount of excess fibrillar collagen deposited in the ECM in cultured primary human lung fibroblasts, a bleomycin mouse model, and a cultured human precision-cut lung slice model of lung fibrosis.
View Article and Find Full Text PDFFront Immunol
December 2024
The R&D Department of Betta Biologic, Betta Pharmaceuticals Co. Ltd, Hangzhou, Zhejiang, China.
Background: In the tumor microenvironment (TME), the transforming growth factor-β (TGF-β) and programmed cell death receptor 1 (PD-1)/programmed death ligand 1 (PD-L1) signaling axes are complementary, nonredundant immunosuppressive signaling pathways. Studies have revealed that active TGF-β is mainly released from the glycoprotein A repetitions predominant (GARP)-TGF-β complex on the surface of activated regulatory T cells (Tregs), B cells, natural killer (NK) cells, and tumor cells. The currently available antibodies or fusion proteins that target TGF-β are limited in their abilities to simultaneously block TGF-β release and neutralize active TGF-β in the TME, thus limiting their antitumor effects.
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