Endocrine Abstracts

Activation of the Ras/ERK pathway and stimulation of proliferation by integrins in thyroid cells requires CaMKII activation. To date, whether this role of CaMKII is a general mechanism or is restricted to integrin signalling is unknown. As oncogenic activation of the Ras/ERK pathway by mutated Ras, RET/PTC and Trk is frequent in papillary thyroid carcinoma (PTC), we investigated the expression and activation level of CaMKII in PTC primary culture and in stable cell lines.<...

Recent studies demonstrated that the calcium/calmodulin dependent kinase 2 (CaMKII) is involved in the regulation of proliferation and survival of epithelial cells, were it phosphorylates RAF-1 and modulates MAPK pathway. A endogenous CaMKII inhibitor (hCaKIINα) is expressed in some cell types. It is down-expressed in colon and in ovarian cancer where it inversely correlates with the disease extension.Aim of our study is to determine the possible ro...

The family of calcium/calmodulin-dependent protein kinases (CaMK) are major effectors of calcium binding proteins in virtually all systems. Recently, CaMKs have been implicated in regulating pituitary and hypothalamic gene transcription to control the expression of gonadotrophin hormones and adrenocorticotrophin in the pituitary, and as a pivotal protein in the satiety pathway. Despite these observations, the spatial and temporal expression of the CaMKs is poorly documented an...

Regulation of many pituitary-specific genes involves calcium signalling, yet the mechanisms and signalling molecules involved have yet to be established. CaMK's are expressed in a wide variety of tissues, and are known to modulate transcriptional regulators such as MAPK's and CREB. It is unclear as to which anterior pituitary cell types express CaMK's, or which isoforms are present. We have examined the presence and localisation of type II and IV CaMK's in alphaT3-1, LbetaT2 (...

Introduction: Interleukin (IL)-6 can activate signal transducer and activator of transcription (STAT)3-dependent signaling similar to leptin in neurons. Here we demonstrate that central application of IL-6 suppresses feeding and improves glucose tolerance in mice. Furthermore, we found that central IL-6 trans-signaling is enhanced in obese mice to improve anorexigenic and glucoregulatory effects of IL-6.Methods/design: Glucose tolerance and insulin sensi...

Brain ageing associates decreased neuronal plasticity, increased glucocorticoid and decreased retinoic acid (RA) signalling. We previously showed an interaction of these pathways on the regulation of a synaptic plasticity gene, BDNF. We thus investigated the effects of GC and RA on two BDNF-dependent genes: activity-regulated cytoskeleton protein (Arc) and Ca2+/calmodulin-dependent protein kinase II (CaMK). Dexamethasone (Dex, 10−6 M) and/or RA (10<...

The pulsatile release of GnRH regulates the synthesis and secretion of pituitary FSH and LH. Two transcription factors, the cAMP response element binding protein (CREB) and inducible cAMP early repressor (ICER), have been implicated in the regulation of rat FSHβ gene expression. We hypothesized that CREB and ICER are activated by distinct signaling pathways in response to pulsatile GnRH to modulate FSHβ gene expression, which is preferentially stimulated at low (ever...

GnRH is released from the hypothalamus in a pulsatile manner and binds to specific receptors (GnRHR) in the anterior pituitary gland to stimulate follicle-stimulating hormone (FSH) and luteinizing hormone (LH) subunit gene expression and subsequent FSHβ and LHsecretion. The FSH and LH subunits are preferentially stimulated by pulsatile GnRH at low and high pulse frequencies, respectively. The transcription factors, cAMP response element binding protein (CREB) and inducibl...