Search results for "Ascidian"

Tributyltin chloride-induced effects on protein tyrosine phosphorylation and on extracellular-signal-regulated kinase (ERK) phosphorilation in Ascidi…

2011

Ascidians represent an intriguing candidate experimental system for studying the effects of environmental stress. We studied TBT effects and probable related pathways were investigated on ascidian embryos by using Western immunoblotting. Among the various signal transduction pathways involved in response to environmental stress, both tyrosine kinase signalling and MAPKs have been played a significant role. To better understand molecular mechanisms after exposure to TBT we studied the two signal transduction pathways above mentioned. Attempting to unravel the molecular effects of TBT-induced on ascidians embryogenesis, TBT treatments carried out in Phallusia mammillata embryos at gastrula st…

Effects of tributyltin chloride in ascidian embryos: modulation of kinase-mediated signalling pathways

2009

We studied the effects of various TBT concentrations by assaying the activity of ERK 1/2 (p44/42) and phospho-ERK1/2 (phospho-p44/42), proteins with a key role in ascidian development, and tyrosine kinase-dependent pathway. The effects of this xenobiotic and the role of some signalling mechanisms on ascidian embryos were examined by using Western immunoblotting. The tyrosine phosphorylation pattern in the ascidians Ciona intestinalis and Phallusia mammillata development was examined and different levels of protein phosphorylation were found as a response to TBT at μM range. To determine whether another key signalling pathway was activated, the effects of TBT on the phosphorylation state of …

Inflammatory Response of the Ascidian Ciona intestinalis

2016

Abstract The Ciona intestinalis inflammatory response to several irritants appears to be composed of a complex reaction set. The cellular reactions in the tunic involve hemocyte infiltration, hemocyte and epidermis activities, vacuolization, and cell disruption, while cell products can contribute to form capsule components and/or cause a tunic wound. In this response, the involvement of the pharynx, as the main immune-competent organ, has been disclosed by a lipopolysaccharide challenge that upregulates innate immunity genes and transcription activation genes. The pharynx responds through hemocyte recruitment into the pharynx vessels, enhancement of galectin-like lectins in the serum hemoly…

A preliminary study on antimicrobial peptides in the naturally damaged tunic of Ciona intestinalis (Tunicata)

2011

Phenoloxidases of different sizes are modulated by LPS inoculation into ciona intestinalis tunic and pharynx

2015

In the present study, to further characterize the pro-phenoloxidase (proPO) and active phenoloxidase (PO) involved in the Ciona intestinalis inflammatory response, tunic and pharynx homogenate supernatants were separated on high pressure liquid chromatography and fractions were assayed for the PO activity before and after LPS inoculation, as well as before and after trypsin treatment which activates proPO. The LPS inoculation per se did not significantly change the basal PO activity of the tunic homogenate supernatant (THS) and pharynx homogenate supernatant (PHS) restricted in two confluent peaks, whereas a significant enhancement was observable after the trypsin treatment. This trypsin ef…

Routes in Innate Immunity Evolution: Galectins and Rhamnose-binding Lectins in Ascidians

2013

Identification of CPE and GAIT elements in 3’UTR of macrophage migration inhibitory factor (MIF) involved in inflammatory response induced by LPS in …

2018

Innate immune responses face infectious microorganisms by inducing inflammatory responses. Multiple genes within distinct functional categories are coordinately and temporally regulated by transcriptional 'on' and 'off' switches that account for the specificity of gene expression in response to external stimuli. Mechanisms that control transcriptional and post-transcriptional regulation are important in coordinating the initiation and resolution of inflammation. Macrophage migration inhibitory factor (MIF) is an important cytokine that, in Ciona robusta, is related to inflammatory response. It is well known that in C. robusta, formerly known as Ciona intestinalis, the pharynx is involved in…

Upregulated transcription of phenoloxidase genes in the pharynx and endostyle of Ciona intestinalis in response to LPS

2015

We investigated the role of phenoloxidases (POs) in ascidians inflammatory reaction, a components of a copper-containing protein family involved in invertebrate immune system. In Ciona intestinalis two phenoloxidases (CinPO-1, CinPO-2) have been sequenced. In the present study, real time PCR analysis showed that both CinPO-1 and CinPO-2 genes were modulated by LPS inoculation suggesting that they are inducible and highly expressed in the inflamed pharynx. In situ hybridization disclosed CinPO-1 and CinPO-2 transcripts in pharynx hemocytes (granulocytes) and, mainly, in unilocular refractile granulocytes (URG) which mainly populated the inflamed tunic matrix. Interestingly, the genes are als…

Ciona intestinalis interleukin 17-like genes expression is upregulated by LPS challenge

2015

In humans, IL-17 is a proinflammatory cytokine that plays a key role in the clearance of extracellular bacteria promoting cell infiltration and production of several cytokines and chemokines. Here, we report on three Ciona intestinalis IL-17 homologues (CiIL17-1, CiIL17-2, CiIL17-3). The gene organisation, phylogenetic tree and modelling supported the close relationship with the mammalian IL-17A and IL-17F suggesting that the C. intestinalis IL-17 genes share a common ancestor in the chordate lineages. Real time PCR analysis showed a prompt expression induced by LPS inoculation suggesting that they are involved in the first phase of inflammatory response. In situ hybridization assays disclo…

Inducible lectins with galectin properties and human IL1alpha epitopes opsonize yeast during the inflammatory response of the ascidian Ciona intestin…

2007

Studies on inducible ascidian lectins may shed light on the evolutionary emergence of cytokine functions. Here, we show that the levels of opsonins, with IL1alpha-epitopes, increase in Ciona intestinalis hemolymph as a response to an inflammatory stimulus and, in particular, to intratunic injection of lipopolysaccharide (LPS). The inflammatory agent promptly (within 4 h) enhances Ca(2+)-independent serum hemagglutinating and opsonizing activities, which are both inhibited by D-galactose and D-galactosides (alpha-lactose, N-acetyl-D-lactosamine, thio-digalactoside), suggesting that anti-rabbit erythrocyte lectins with galectin properties are involved as opsonins. Inducible galectin molecules…