Search results for "Pathway"
showing 10 items of 1685 documents
The physiological basis for the computation of direction selectivity in theDrosophilaOFF pathway
2021
AbstractInDrosophila, direction-selective neurons implement a mechanism of motion computation similar to cortical neurons, using contrast-opponent receptive fields with ON and OFF subunits. It is not clear how the presynaptic circuitry of direction-selective neurons in the OFF pathway supports this computation, because all major inputs are OFF-rectified neurons. Here, we reveal the biological substrate for motion computation in the OFF pathway. Three interneurons, Tm2, Tm9 and CT1, also provide information about ON stimuli to the OFF direction-selective neuron T5 across its receptive field, supporting a contrast-opponent receptive field organization. Consistent with its prominent role in mo…
Putative p24 complexes in Arabidopsis contain members of the delta and beta subfamilies and cycle in the early secretory pathway
2013
p24 proteins are a family of type I membrane proteins localized to compartments of the early secretory pathway and to coat protein I (COPI)- and COPII-coated vesicles. They can be classified, by sequence homology, into four subfamilies, named p24α, p24β, p24γ, and p24δ. In contrast to animals and fungi, plants contain only members of the p24β and p24δ subfamilies, the latter probably including two different subclasses. It has previously been shown that transiently expressed red fluorescent protein (RFP)-p24δ5 (p24δ1 subclass) localizes to the endoplasmic reticulum (ER) at steady state as a consequence of highly efficient COPI-based recycling from the Golgi apparatus. It is now shown that tr…
Activin A and bone metastasis
2010
Activin A, is a multifunctional cytokine of the transforming growth factor-b superfamily of growth factors. This molecule has been shown to be implicated in the regulation of a broad range of important biological functions including bone remodelling. Therefore, a deregulation in the activin signalling pathway may result in disturbances of normal bone metabolism and, eventually, in the onset of severe pathological conditions associated with an altered bone resorption. These observations support the concept that Act A might also be implicated in the pathogenesis of bone metastasis. This review provides insight into the most recent advances in understanding the role of this growth factor in th…
Relations between basal ganglia and hippocampus: Action of substantia nigra and pallidum
1986
Several interrelationships exist between basal ganglia and hippocampus. The ventral striatum appears to be involved in the control of the dopaminergic nigro-striatal pathway. The caudate, in turn, seems to influence the hippocampal theta rhythm and to inhibit hippocampal spikes. In the present work the role played by globus pallidus pars interna and substantia nigra pars compacta on hippocampal bioelectrical activity is studied. Injection of sodium penicillin i.v. produces steady interictal spikes in the hippocampus. Substantia nigra stimulation induces regular theta rhythm and inhibits the spikes. Pallidal stimulation, on the contrary, appears to strongly enhance epileptiform activity, pro…
Coupled transport of Arabidopsis p24 proteins at the ER–Golgi interface
2012
p24 proteins are a family of type I membrane proteins localized to compartments of the early secretory pathway and to coat protein I (COPI)- and COPII-coated vesicles. They can be classified, by sequence homology, into four subfamilies, named p24α, p24β, p24γ, and p24δ. In contrast to animals and fungi, plants contain only members of the p24β and p24δ subfamilies. It has previously been shown that transiently expressed red fluorescent protein (RFP)–p24δ5 localizes to the endoplasmic reticulum (ER) as a consequence of highly efficient COPI-based recycling from the Golgi apparatus. Using specific antibodies, endogenous p24δ5 has now been localized to the ER and p24β2 to the Golgi apparatus in…
Evidence for extrinsic control of oesophageal primary peristalsis.
1985
AbstractThe role of both peripheral and central mechanism in the control of primary peristalsis was studied in pigeon cervical oesophagus.The results from the transection of oesophageal muscular wall and of extrinsic nerves suggest that :i) primary peristalsis is programmed centrally.ii) extrinsic motor input is carried in glossopharyngeal nerves and distributed separately at each oesophageal level through intramural neurons.iii) intramural neurons do not seem capable of propagating the peristaltic sequence irrespective of the central control.
The Synergistic Effect of SAHA and Parthenolide in MDA-MB231 Breast Cancer Cells
2015
The sesquiterpene lactone Parthenolide (PN) exerted a cytotoxic effect on MDA-MB231 cells, a triple-negative breast cancer (TNBC) cell line, but its effectiveness was scarce when employed at low doses. This represents an obstacle for a therapeutic utilization of PN. In order to overcome this difficulty we associated to PN the suberoylanilide hydroxamic acid (SAHA), an histone deacetylase inhibitor. Our results show that SAHA synergistically sensitized MDA-MB231 cells to the cytotoxic effect of PN. It is noteworthy that treatment with PN alone stimulated the survival pathway Akt/mTOR and the consequent nuclear translocation of Nrf2, while treatment with SAHA alone induced autophagic activity…
Plasmalogens in the retina: From occurrence in retinal cell membranes to potential involvement in pathophysiology of retinal diseases
2014
Plasmalogens (Pls) represent a specific subclass of glycerophospholipids characterized by the presence of a vinyl-ether bond at the sn-1 position of glycerol. Pls are quantitatively important in membranes of neuronal tissues, including the brain and the retina, where they can represent until almost two-third of ethanolamine glycerophospholipids. They are considered as reservoirs of polyunsaturated fatty acids as several studies have shown that arachidonic and docosahexaenoic acids are preferentially esterified on Pls when compared to other glycerophospholipids. Reduced levels of Pls were observed in a number of neurodegenerative disorders such as glaucoma, the second leading cause of blindn…
A critical role of plastidial glycolytic Glyceraldehyde-3-Phosphate Dehydrogenase in the control of plant metabolism and development
2009
3 páginas.
Expression of the Sonic Hedgehog Embryonic Signalling Pathway Components in Matched Pre-Treatment and Relapsed Small Cell Lung Cancer Biopsies
2021
Abstract Cancer stem cells may be responsible for tumour regrowth and acquisition of resistance in small cell lung cancer (SCLC). The Hedgehog pathway regulates survival and proliferation of tissue progenitor and stem cell populations, promoting the expression of stem cell related and proliferative genes. We evaluated the Sonic Hedgehog (Shh) embryonic signalling pathway in relapsed SCLC. Expression levels of Shh related genes GLI1, SMO, SUFU, PTCH1, HHIP, BCL2, BMI, ZEB1, ZEB2, N-MYC, Twist1 were analysed by qRT-PCR in matched pre-treatment and relapsed tumour fresh frozen biopsies of three SCLC patients. Expression of each gene was compared using the paired samples t-test, as well as comp…