Browsing by Subject "Receptor"
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- PublicationOpen AccessEnhancement of anion recognition exhibited by a zinc-imidazole-based ion-pair receptor composed of C–H hydrogen- and halogen-bond donor groups(Royal Society of Chemistry, ) Zapata Fernández, Fabiola; Sabater, Paula; López, Bernardo; Fernández, Israel; Caballero, Antonio; Molina, Pedro; Química OrgánicaA 2-haloimidazole-tetraphenylethylene ion-pair receptor 1 is shown to recognise only HSO4− anions in the presence of a cobound Zn2+ cation guest species, which induced a remarkable increase with conco- mitant blue shift of the emission band of the complex [1·2Zn]4+ whereas no affinity of the free receptor 1 by the anions is observed. In addition, the downfield shifts observed by 1H NMR of the Ha, Hb and Hc protons of the complex [1·2Zn]4+ upon the addition of HSO4− anions indicate their participation in the recognition event. According to DFT studies, upon chelating a Zn2+ cation with two imidazole nitrogen atoms, receptor 1 adopts a conformation ideally fitted to recognise HSO4− through a combination of C(sp2)–H⋯O and C(sp3)–H⋯O hydrogen bondings, C+(sp2)–Br⋯O halogen bonding and C(sp2)⋯O tetrel bonding."
- PublicationOpen AccessExtracellular ATP activates the NLRP3 inflammasome and is an early danger signal of skin allograft rejection(Elsevier, 2017-12-19) Amores Iniesta, Joaquín; Barberá Cremades, María; Parrilla, Pascual; Baroja Mazo, Alberto; Martínez Cáceres, Carlos Manuel; Pelegrín Vivancos, Pablo; Anatomía y Anatomía Patológica ComparadasImmune cells are equipped with a number of receptors that recognize sterile injury and pathogens. We find that host immune cells release ATP as an inflammatory signal in response to allogeneic transplantation. ATP then acts via a feedback mechanism on the P2X7 channel to activate the NLRP3 inflammasome and subsequently process and release interleukin (IL)-18. This process is a necessary stage in the deleterious Th1 response against allotransplantation via interferon-γ production. Lack of IL-18 resulted in a decrease in graft-infiltrating CD8 cells but an increase in regulatory T cells. In human liver transplant patients undergoing progressive immunosuppressive drug withdrawal, we found that patients experiencing acute rejection had higher levels of the P2X7 receptor in circulating inflammatory monocytes compared to tolerant patients. These data suggest that the pharmacological inhibition of the P2X7 receptor or the NLRP3 inflammasome will aid in inducing transplant tolerance without complete immunoparalysis.
- PublicationOpen AccessLocalization of advanced glycation end-products and their receptor in tendinopathic lesions(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Asomugha, Eva; Cho, Young; Paudel, Sharada; Guo, Yi; Schon, Lew; Zhang, ZijunThis study was designed to investigate the accumulation of advanced glycation end-products (AGEs) and the expression of the receptor of AGEs (RAGE) in tendinopathic tissues. In this study, tendinopathic posterior tibial tendons (PTT) were collected from patients (n=6). Redundant autografts of flexor digitorum longus tendon (FDL; n=3) were used for controls. The control and tendinopathic tendon tissues were used for extraction of proteins for western blot and sectioned for histology and immunohisto-chemistry. Tendinopathy of the PTT was confirmed histologically by the presentation of disorderly collagen fibers, high cellularity and increased vascularity. By immunohistochemistry, heterogeneous accumulation of AGEs was detected on the PTT sections and concentrated in areas, where collagen fibers were disorderly and tangled. In the PTT, roundish tenocytes were also AGEs-positive. In contrast, AGEs were diffuse, lightly stained in the FDL. A greater number of tenocytes within the tendinopathic lesions in the PTT were RAGE positive, compared to the tenocytes in the FDL. Western blot confirmed the presence of AGEs and RAGE in both tendinopathic PTT and control FDL but their band densities were not significantly different. The spatial relation of the accumulated AGEs and RAGE- positive tenocytes within the tendinopathic lesions indicates their involvement in the molecular pathology of tendinopathy.
- PublicationOpen AccessRespiratory syncytial virus receptor expression in the mouse and viral tropism(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Shakeri, Aria; Mastrangelo, Peter; Griffin, Jennifer K.; Moraes, Theo J.; Hegele, Richard G.Human respiratory syncytial virus (RSV) infects airway epithelium and can cause serious illnesses such as bronchiolitis and pneumonia. With the discovery of cell-surface nucleolin as a fusion receptor for RSV, the question arose as to whether nucleolin could explain RSV tropism in vivo. Here, we report the distribution of cell-surface nucleolin expression in tissues of normal mice and how this distribution of expression relates to what is known about RSV tropism and its clinical manifestations. Our results show evidence of cellsurface nucleolin expression in the respiratory tract. In addition, cell-surface nucleolin is expressed in tissues outside of the respiratory tract, many of which correspond to previous reports of tissue-specific RSV infection, and others that may allude to additional potential sites for RSV infection in vivo. Furthermore, our work provides a foundation for the investigation of nucleolin’s physiological function in various healthy mammalian tissues.
- PublicationOpen AccessRole of discoidin domain receptor 2 in wound healing(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2014) Márquez, Joana; Olaso, ElviraUntil recently, collagen interactions with cells had been ascribed to integrins. The identification of the Discoidin Domain Receptor (DDR) family as collagen receptors represents a new paradigm in the regulation of collagen-cell interactions. How DDR signaling is biochemically linked to specific cell regulatory functions remains largely unknown. Moreover, the characteristic slow and substained phosphorylation of DDRs and the elevated expression of DDR2 in the myofibroblasts of healing wounds suggest a role for DDR2 in physiological and pathological wound healing. In fact, DDR2 signaling regulates cell proliferation and extracellular matrix synthesis, which are key aspects of fibroblast contribution to tissue healing. In this review we summarize evidence in favor of this concept.
- PublicationOpen AccessThe pivotal role of PDGF and its receptor isoforms in adipose-derived stem cells(Universidad de Murcia. Servicio de publicaciones, 2015) Kim, Won-Serk; Park, Hyoung-Sook; Sung, Jong-HyukPlatelet-derived growth factor (PDGF) is one of the growth factors that reportedly regulates cell growth and division of mesenchymal cells. Although PDGF isoforms and their receptors reportedly play a pivotal role in mesenchymal stem cell regulation, there is a paucity of literature reviewing the role of PDGF in adipose-derived stem cells (ASCs). Therefore, we summarized previous reports on the expression and functional roles of PDGF and its receptor isoforms in this review. In addition, we examined findings pertaining to underlying molecular mechanisms and signaling pathways with special focus on PDGF-D/PDGFRβ. ASCs only express PDGF-A, -C, -D, PDGFRα, and PDGFRβ. PDGFRα expression decreases with adipocyte lineage, while PDGFRβ inhibits white adipocyte differentiation. In addition, PDGFRβ induces proliferation, migration, and angiogenesis and upregulates the expression of paracrine factors in ASCs. Although PDGF-B and -D mediate their functions mainly by PDGFRβ and ROS generation, there are many differences between them in terms of regulating ASCs. PDGF-D is endogenous, generates ROS via the mitochondrial electron transport system, and regulates the autocrine loop of ASCs in vivo. Furthermore, PDGFD has stronger mitogenic effects than PDGF-B.