Search results for "Autocrine signalling"
showing 8 items of 68 documents
Inhibition of ovarian steroidogenesis by cyclic-GMP in a fly
2003
1479-6805 0022-0795; Previous investigations in the female blowfly Phormia regina have shown that 3-isobutyl-1-methylxanthine (IBMX), a broad spectrum inhibitor of phosphodiesterases (PDEs), fails to mimic the steroidogenic effects of cAMP on ovaries, although it efficiently increases the concentrations of this second messenger. In this study, experiments carried out to clear up this contradiction demonstrated that IBMX, besides its effect on cAMP, also increased cGMP concentrations in blowfly ovary and that these two cyclic nucleotides controlled ovarian steroidogenesis antagonistically. In particular, a selective inhibitor of cGMP-specific PDEs, unlike IBMX, had a very strong negative eff…
The role of insulin-like growth factor II in the malignant transformation of rat liver oval cells
1997
Oval cells are small nonparenchymal epithelial cells that first appear in the periportal areas of the liver and thereafter invade the whole parenchyma when mice or rats are exposed to a variety of chemical carcinogens. In the present study we have analyzed the expression of insulin-like growth factor II (IGF II) in the recently established oval cell line OC/CDE 22 and its malignantly transformed counterpart (the M22 cells) and the biological consequences of the constitutive expression of IGF II in oval cells. OC/CDE 22 cells do not express the above-mentioned growth factor, whereas the M22 cells do and addition of a neutralizing anti-IGF II antibody to M22 cells resulted in an almost comple…
Neuromuscular electrical stimulation: a new therapeutic option for chronic diseases based on contraction-induced myokine secretion
2019
Myokines are peptides known to modulate brain neuroplasticity, adipocyte metabolism, bone mineralization, endothelium repair and cell growth arrest in colon and breast cancer, among other processes. Repeated skeletal muscle contraction induces the production and secretion of myokines, which have a wide range of functions in different tissues and organs. This new role of skeletal muscle as a secretory organ means skeletal muscle contraction could be a key player in the prevention and/or management of chronic disease. However, some individuals are not capable of optimal physical exercise in terms of adequate duration, intensity or muscles involved, and therefore they may be virtually deprived…
Cigarette smoke alters non-neuronal cholinergic system components inducing MUC5AC production in the H292 cell line.
2013
Abstract Cigarette smoke extract (CSE) affects the expression of Choline Acetyl-Transferase (ChAT), muscarinic acetylcholine receptors, and mucin production in bronchial epithelial cells. Mucin 5AC (MUC5AC), muscarinic acetylcholine receptor M3, ChAT expression, acetylcholine levels and acetylcholine binding were measured in a human pulmonary mucoepidermoid carcinoma cell line (H292) stimulated with CSE. We performed ChAT/RNA interference experiments in H292 cells stimulated with CSE to study the role of ChAT/acetylcholine in MUC5AC production. The effects of Hemicholinium-3 (HCh-3) (50 μM) (a potent and selective choline uptake blocker) and Tiotropium bromide (Spiriva ® ) (100 nM), alone o…
BDNF is essentially required for the early postnatal survival of nociceptors
2010
AbstractNeurotrophins promote the survival of specific types of neurons during development and ensure proper maintenance and function of mature responsive neurons. Significant effects of BDNF (Brain-Derived Neurotrophic Factor) on pain physiology have been reported but the contribution of this neurotrophin to the development of nociceptors has not been investigated. We present evidence that BDNF is required for the survival of a significant fraction of peptidergic and non-peptidergic nociceptors in dorsal root ganglia (DRG) postnatally. Bdnf homozygous mutant mice lose approximately half of all nociceptive neurons during the first 2 weeks of life and adult heterozygotes exhibit hypoalgesia …
Chick embryo retina development in vitro: the effect of insulin.
1995
In this paper we study the development of chick embryo retina cultured in vitro and the effects exerted by insulin. Retinas were removed from 7-day embryos and cultured in serum- and hormone-free medium for 7 additional days. Under these conditions retinal cells survived and underwent cholinergic differentiation, as previously ascertained by Hausman et al. (Dev. Brain Res., 1991, 59: 31-37). However, a great retardation of development was noted compared to uncultured control, 14-day retina. In fact both wet weight and DNA and protein content increased much slower than in ovo and the tubulin content decreased below even the starting value. In addition, although after 7 days in culture retina…
Role of insulin-like growth factors in autocrine growth of human retinoblastoma Y79 cells.
1996
In this study, we have demonstrated that human retinoblastoma Y79 cells produce insulin-like growth factors (IGFs) type I and type II and release them into the medium. We have also ascertained, by means of competitive studies and cross-linking procedure, that Y79 cells contain the type-I IGF receptor (IGF-IR). Furthermore, surface-bound IGF-I is internalised by the receptor, then degraded to amino acids. Insulin, IGF-I and IGF-II caused down-regulation of IGF-IR; the effect is concentration and time dependant. Scatchard analysis demonstrated that incubation with insulin markedly decreased the binding capacity measured for IGF-I while the apparent Kd value calculated for IGF-I binding was no…
Efficient Killing of Human Colon Cancer Stem Cells by γδ T Lymphocytes
2009
Abstract Colon cancer comprises a small population of cancer stem cells (CSC) that is responsible for tumor maintenance and resistant to cancer therapies, possibly allowing for tumor recapitulation once treatment stops. We previously demonstrated that such chemoresistance is mediated by autocrine production of IL-4 through the up-regulation of antiapoptotic proteins. Several innate and adaptive immune effector cells allow for the recognition and destruction of cancer precursors before they constitute the tumor mass. However, cellular immune-based therapies have not been experimented yet in the population of CSCs. Here, we show that the bisphosphonate zoledronate sensitizes colon CSCs to Vγ9…