Aims: Multiple phosphodiesterases (PDEs) hydrolyze cAMP in cardiomyocytes, but the functional significance of this diversity is not well understood. Our goal here was to characterize the involvement of three different PDEs (PDE2-4) in cardiac excitation-contraction coupling (ECC).
Methods And Results: Sarcomere shortening and Ca(2+) transients were recorded simultaneously in adult rat ventricular myocytes and ECC protein phosphorylation by PKA was determined by western blot analysis.
The sympathetic nervous system and pro-inflammatory cytokines play key roles in numerous cardiovascular disorders. Chronic beta-adrenergic receptor (beta-AR) stimulation in myocardium induces expression of pro-inflammatory cytokines, such as interleukin-1 (IL-1) and interleukin-6 (IL-6), which contribute to cardiac hypertrophy and failure. To evaluate the relationship between beta-AR stimulation and pro-inflammatory cytokines, we studied the effects of the beta-AR agonist isoprenaline (ISO) on IL-1-induced IL-6 production in adult rat ventricular myocytes (ARVMs).
View Article and Find Full Text PDFInterleukin-6 (IL-6) is a multifunctional cytokine involved in autoimmune thyroid diseases such as Hashimoto's thyroiditis and Graves' disease. IL-6 is produced by infiltrating immune cells and by thyrocytes. In the latter cell type, secretion of IL-6 is stimulated notably by interleukin-1 (IL-1), thyroid-stimulating hormone (TSH) or forskolin (Fk), a cAMP elevating agent.
View Article and Find Full Text PDFInteractions of environmental pollutants with the thyroid endocrine axis have received much attention especially because thyroid hormones (THs) play a major role in mammalian brain development. In order to screen for compounds that act on the triiodothyronine (T3) signaling pathway, we developed a new reporter gene assay expressing luciferase under the control of the TH receptor (TR). PC12 cells expressing the alpha1-isoform of TR of avian origin were stably transfected with a luciferase gene controlled by the SV40 promoter, and enhanced by a four-spaced direct repeat (DR4) thyroid response element (TRE).
View Article and Find Full Text PDFThe p38 family of MAP kinases (p38-MAPKs) is involved in regulating the proliferation, survival, and migration of various cancer cells. The present study has investigated the expression, subcellular localization, phosphorylation, and activity of p38-MAPKs in normal and tumoural human thyroid tissues and in thyroid cell lines. The expression and nucleo-cytosolic compartmentalization of the alpha-isoform of p38-MAPKs (p38alpha-MAPK) were studied by western blotting in the WRO and B-CPAP cell lines, which are derived from human follicular and papillary thyroid carcinomas, respectively, and in the non-transformed rat thyroid cell lines FRTL-5 and PCCL3.
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