scholarly journals Stimulation of hepatocarcinogenesis by activated cholangiocytes via Il17a/f1 pathway in kras transgenic zebrafish model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamed Helal ◽  
Chuan Yan ◽  
Zhiuyan Gong
Keyword(s):  
Tumor Cells ◽  
Proliferative Response ◽  
Gene Expression Analysis ◽  
Transgenic Zebrafish ◽  
Zebrafish Model ◽  
Secreted Factors ◽  
Sphingosine 1 Phosphate ◽  
Dependent Pathway ◽  
Stimulation Of

AbstractIt has been well known that tumor progression is dependent on secreted factors not only from tumor cells but also from other surrounding non-tumor cells. In the current study, we investigated the role of cholangiocytes during hepatocarcinogenesis following induction of oncogenic krasV12 expression in hepatocytes using an inducible transgenic zebrafish model. Upon induction of carcinogenesis in hepatocytes, a progressive cell proliferation in cholangiocytes was observed. The proliferative response in cholangiocytes was induced by enhanced lipogenesis and bile acids secretion from hepatocytes through activation of Sphingosine 1 phosphate receptor 2 (S1pr2), a known cholangiocyte receptor involving in cholangiocyte proliferation. Enhancement and inhibition of S1pr2 could accelerate or inhibit cholangiocyte proliferation and hepatocarcinogenesis respectively. Gene expression analysis of hepatocytes and cholangiocytes showed that cholangiocytes stimulated carcinogenesis in hepatocytes via an inflammatory cytokine, Il17a/f1, which activated its receptor (Il17ra1a) on hepatocytes and enhanced hepatocarcinogenesis via an ERK dependent pathway. Thus, the enhancing effect of cholangiocytes on hepatocarcinogenesis is likely via an inflammatory loop.

scholarly journals Author Correction: Stimulation of hepatocarcinogenesis by activated cholangiocytes via Il17a/f1 pathway in kras transgenic zebrafish model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamed Helal ◽  
Chuan Yan ◽  
Zhiyuan Gong
Keyword(s):  
Transgenic Zebrafish ◽  
Zebrafish Model ◽  
Stimulation Of

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Stimulation of calcium influx by platelet activating factor in Dictyostelium

1995 ◽  
Vol 108 (4) ◽  
pp. 1597-1603
Author(s):  
R. Schaloske ◽  
C. Sordano ◽  
S. Bozzaro ◽  
D. Malchow
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Dictyostelium Discoideum ◽  
Calcium Influx ◽  
Platelet Activating Factor ◽  
Inactive Compound ◽  
Time Period ◽  
Dependent Pathway ◽  
Stimulation Of

Platelet activating factor (PAF) induces Ca2+ influx in Dictyostelium discoideum. In this investigation we used this activity to analyze the mechanism of PAF action. We found that PAF activity was confined to the period of spike-shaped oscillations and suggest that the role of PAF is to augment cAMP relay. PAF seems to act only a few times during this time period of two hours, since Ca2+ entry adapted to a subsequent stimulus for about 30 minutes. PAF showed a reduced response in the G protein beta- strain LW14 and was unable to induce Ca2+ influx in the G alpha 2- strains HC85 and JM1. The latter expresses the cAMP receptors cAR1 constitutively, and exhibits cAMP-induced Ca2+ influx, albeit at a reduced level. In order to decide whether the inability of PAF to elicit a Ca2+ response in JM1 cells was due to the lack of differentiation and/or the lack of G alpha 2, we inhibited the IP3-dependent pathway with compound U73122 and found that Ca2+ entry was blocked, whereas a closely related inactive compound, U73343, did not alter the response. In agreement with this, NBD-Cl, an inhibitor of Ca2+ uptake into the IP3-sensitive store in Dictyostelium, also abolished PAF activity. The latter was not inhibited by the plasma membrane antagonists BN-52021 or WEB 2170. Therefore PAF seems to operate intracellularly via the IP3-signalling pathway at or upstream of the IP3-sensitive store.

Involvement of phospholipase C in endothelin 1–induced stimulation of Ca++ channels and basilar artery contraction in rabbits

2006 ◽  
Vol 105 (2) ◽  
pp. 288-293 ◽  
Author(s):  
Yoshifumi Kawanabe ◽  
Tomoh Masaki ◽  
Nobuo Hashimoto
Keyword(s):  
Phospholipase C ◽  
Essential Role ◽  
Ca Channels ◽  
Endothelin 1 ◽  
Nonselective Cation Channels ◽  
Basilar Arteries ◽  
Independent Cascade ◽  
Dependent Pathway ◽  
Stimulation Of

Object Endothelin 1 (ET-1) is a major cause of cerebral vasospasm after subarachnoid hemorrhage (SAH), and extracellular Ca++ influx plays an essential role in ET-1–induced vasospasm. The authors recently demonstrated that ET-1 activates two types of Ca++-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and a store-operated Ca++ channel (SOCC) in vascular smooth-muscle cells located in the basilar arteries (BAs) of rabbits. In the present study, they investigate the effects of phospholipase C (PLC) on ET-1–induced activation of these Ca++ channels and BA contraction by using the PLC inhibitor U73122. Methods To determine which Ca++ channels are activated via a PLC-dependent pathway, these investigators monitored the intracellular free Ca++ concentration ([Ca++]i). The role of PLC in ET-1–induced vascular contraction was examined by performing a tension study of rabbit BA rings. The U73122 inhibited the ET-1–induced transient increase in [Ca++]i, which resulted from mobilization of Ca++; from the intracellular store. Phospholipase C also inhibited ET-1–induced extracellular Ca++ influx through the SOCC and NSCC-2, but not through the NSCC-1. The U73122 inhibited the ET-1–induced contraction of the rabbit BA rings, which depended on extracellular Ca++ influx through the SOCC and NSCC-2. Conclusions These results indicate the following. 1) The SOCC and NSCC-2 are stimulated by ET-1 via a PLC-dependent cascade whereas NSCC-1 is stimulated via a PLC-independent cascade. 2) The PLC is involved in the ET-1–induced contraction of rabbit BA rings, which depends on extracellular Ca++ influx through the SOCC and NSCC-2.

scholarly journals Establishment of a stable zg6pdM118-144 transgenic zebrafish model of glucose-6-phosphate dehydrogenase deficiency

2020 ◽  
Author(s):  
Hai-Xiong Xia ◽  
Yan-Hua Zhou ◽  
Yuan-Yuan Tuo ◽  
Ping-Ping Ren ◽  
Jin Song ◽  
...  
Keyword(s):  
G6pd Deficiency ◽  
Genetic Defect ◽  
Clinical Manifestations ◽  
Wide Distribution ◽  
Health Concern ◽  
Transgenic Zebrafish ◽  
Zebrafish Model ◽  
Malaria Therapy ◽  
Glucose 6 Phosphate Dehydrogenase

AbstractGlucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common genetic defect and enzymopathy with a wide distribution and increased public health concern, predisposes subjects succumb to oxidative stress. G6PD deficiency has been associated with hemolysis. Clinically, G6PD deficiency is asymptomatic and the clinical manifestations occur with the exposure to certain agents. Due to the lack of suitable animal models that can predict the clinical hemolytic potential of drugs, it needs an appropriate research model to fully recapitulate the manifestations of G6PD deficiency in clinic, to optimize the malaria therapy and promote anti-malarias development. The present study has displayed a stable transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish model with G6PD deficiency which mimics the clinical features of G6PD deficiency phenotypically and functionally. The findings showed that there was an inadequate level of reduced GSH in the transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish line in the presence or absence of α-naphthol, compared to the wildtype zebrafish, indicating an attenuation of g6pd activity in the transgenic zebrafish line. In addition, the observations show that there is a less abundance of g6pd in the transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish line. On the other hand, there is no morphological abnormality in the transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish line. Taken together, our work has delivered a novel stable transgenic zebrafish model of G6PD deficiency that will facilitate the mechanistic and functional elucidation for the role of G6PD in erythrocytic pathophysiology. This model will promote the translational research for the drug development, in particular, for anti-malarias development.

scholarly journals Nephroprotective Role of Zhibai Dihuang Wan in Aristolochic Acid-Intoxicated Zebrafish

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Ping-Hsun Lu ◽  
Hsun-Yao Lee ◽  
Yan-Liang Liou ◽  
Sheng-Fen Tung ◽  
Ko-Li Kuo ◽  
...  
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Aristolochic Acid ◽  
Transgenic Zebrafish ◽  
Herbal Formula ◽  
Zebrafish Model ◽  
Green Fluorescent ◽  
Nephroprotective Effect ◽  
Kidney Malformations

Zhibai Dihuang Wan (ZDW) is an eight-herbal formula of traditional Chinese medicine. Clinically, it regulated immune activity and was used to treat diabetes and renal disease. In this study, we aimed to explore the nephroprotective effect of ZDW in an aristolochic acid- (AA-) intoxicated zebrafish model. We used a green fluorescent kidney transgenic zebrafish to evaluate the nephroprotective effects of ZDW by recording subtle changes in the kidney. Our results demonstrated that ZDW treatment can attenuate AA-induced kidney malformations (60% for AA-treated, 47% for pretreatment with ZDW, and 17% for cotreatment ZDW with AA, n = 50 ). Furthermore, we found that the expression levels of tnfα and mpo were decreased either in pretreatment or cotreatment groups. In conclusion, our findings revealed that AA-induced nephrotoxicities can be attenuated by ZDW. Therefore, we believe that zebrafish represent an efficient model for screening AA-protective Chinese medicine.

scholarly journals A2B Adenosine Receptors and Sphingosine 1-Phophate Signaling Cross-Talk in Oligodendrogliogenesis

2021 ◽  
Vol 15 ◽  
Author(s):  
Elisabetta Coppi ◽  
Francesca Cencetti ◽  
Federica Cherchi ◽  
Martina Venturini ◽  
Chiara Donati ◽  
...  
Keyword(s):  
Adenosine Receptors ◽  
Adult Life ◽  
Oligodendrocyte Progenitor Cells ◽  
Voltage Dependent ◽  
Sphingosine 1 Phosphate ◽  
Demyelinating Disorders ◽  
S1p Lyase ◽  
Stimulation Of

Oligodendrocyte-formed myelin sheaths allow fast synaptic transmission in the brain. Impairments in the process of myelination, or demyelinating insults, might cause chronic diseases such as multiple sclerosis (MS). Under physiological conditions, remyelination is an ongoing process throughout adult life consisting in the differentiation of oligodendrocyte progenitor cells (OPCs) into mature oligodendrocytes (OLs). During pathological events, this process fails due to unfavorable environment. Adenosine and sphingosine kinase/sphingosine 1-phosphate signaling axes (SphK/S1P) play important roles in remyelination processes. Remarkably, fingolimod (FTY720), a sphingosine analog recently approved for MS treatment, plays important roles in OPC maturation. We recently demonstrated that the selective stimulation of A2B adenosine receptors (A2BRs) inhibit OPC differentiation in vitro and reduce voltage-dependent outward K+ currents (IK) necessary to OPC maturation, whereas specific SphK1 or SphK2 inhibition exerts the opposite effect. During OPC differentiation A2BR expression increases, this effect being prevented by SphK1/2 blockade. Furthermore, selective silencing of A2BR in OPC cultures prompts maturation and, intriguingly, enhances the expression of S1P lyase, the enzyme responsible for irreversible S1P catabolism. Finally, the existence of an interplay between SphK1/S1P pathway and A2BRs in OPCs was confirmed since acute stimulation of A2BRs activates SphK1 by increasing its phosphorylation. Here the role of A2BR and SphK/S1P signaling during oligodendrogenesis is reviewed in detail, with the purpose to shed new light on the interaction between A2BRs and S1P signaling, as eventual innovative targets for the treatment of demyelinating disorders.

scholarly journals In vitro sensitization of thymocytes. Role of H-21 I region determinants and cell-free mixed leukocyte culture supernates in generation of cytotoxic responses.

1978 ◽  
Vol 148 (4) ◽  
pp. 953-962 ◽  
Author(s):  
M Sopori ◽  
A Bernstein ◽  
F H Bach
Keyword(s):  
Proliferative Response ◽  
Spleen Cells ◽  
Leukocyte Culture ◽  
Soluble Cell ◽  
Cytotoxic Responses ◽  
Stimulation Of

Stimulation of thymocytes in vitro by spleen cells differing for the entire H-2 complex leads to a significant proliferative response without a significant cell-mediated lympholysis (CML) response. Addition of soluble cell-free supernates (SF), (taken from a 7-day mixed leukocyte culture) enables these cultures to develop CML response. For optimal CML response, the SF has to be added within 48 h of onset of cultures. Although with spleen cells as responding cells, SF could quantitatively replace I-region different stimulating cells for generation of CML responses, with thymocytes as responding cells, stimulation with I-region cells appeared obligatory for the generation of CML responses. The implications of these findings are discussed.

hDectin-1 Is Involved in the Uptake of Apoptotic and Infected Cells and Mediates Cross-Presentation of Engulfed Antigens.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3086-3086
Author(s):  
Markus M. Weck ◽  
Frank Grünebach ◽  
Daniela Werth ◽  
Lothar Kanz ◽  
Christian Sinzger ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Mammalian Cells ◽  
Specific Binding ◽  
Human Tumor ◽  
Extracellular Domain ◽  
Poly I:C ◽  
Cross Presentation ◽  
Infected Cells ◽  
Stimulation Of

Abstract Dectin-1 is a member of the c-type-lectin-like receptor family that was shown to be the major receptor for fungal beta-glucans and to play an important role in the cellular responses mediated by these carbohydrates. In the present study we identified the hDectin-1b splice variant as the major isoform expressed in in vitro generated mDC using a quantitative RT-PCR and western blot analysis. Interestingly, stimulation of immature DC with the toll like receptor ligands Poly I:C (TLR3) or LPS (TLR4) but not with TLR ligands 2 and 7 or TNF-a led to a dramatic down regulation of hDectin-1 protein expression. To further analyze the possible involvement of Dectin-1 in the phagocytosis of cellular material we recombinantly expressed the extracellular domain (ECD) of hDectin-1b and used it to stain tumor cells. The recombinant ECD showed a specific binding to several human tumor cell lines that could be increased by induction of apoptosis in malignant cells and inhibited by incubation of the extracellular domain with zymosan, a crude cell wall extract of saccharomyces cerevisiae. Furthermore, uptake of tumor cells by immature mDC was reduced by zymosan or the presence of the recombinant Dectin-1 in phagocytosis assays suggesting that Dectin-1 is involved in the engulfement of tumor cells by DC. In line with the expression analysis of hDectin-1, we found that phagocytosis of apoptotic cells was dramatically reduced upon stimulation of DCs with Poly I:C or LPS as compared to immature DC or DC activated with TLR2 or 7 ligands. We next analysed the role of Dectin-1 in the cross-presentation of cell derived antigens and used DC that were incubated with CMV infected fibroblasts and an autologous CTL line specific for the HLA-A2 binding pp65 peptide. Stimulation of CMV peptide specific CTL in ELIspot assays by DC that were incubated with CMV infected fibroblasts efficiently stimulated IFN-gamma secretion that could be inhibited by zymosan and the extracellular domain of Dectin-1. In line with the results from phagocytosis assays stimulation of CMV specific CTL was reduced by stimulation of DC with TLR2 and 4 ligands. Our results identify hDectin-1 as a new receptor for endogenous ligands on mammalian cells and indicate an important role of this molecule in the clearing of apoptotic and infected cells and cross-presentation of cell derived antigens..

scholarly journals Mast cell-mediated tumor-cell cytotoxicity. Role of the peroxidase system.

1981 ◽  
Vol 153 (3) ◽  
pp. 520-533 ◽  
Author(s):  
W R Henderson ◽  
E Y Chi ◽  
E C Jong ◽  
S J Klebanoff
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Tumor Cells ◽  
Mast Cell Degranulation ◽  
Cell Secretion ◽  
51Cr Release ◽  
Tumoricidal Activity ◽  
Endogenous Peroxidase ◽  
Stimulation Of

Mast cells, when supplemented with H2O2 and iodide, are cytotoxic to mammalian tumor cells as determined by 51Cr release, and transmission and scanning electron microscopy. H2O2 at the concentration employed (10(-4) M) initiates mast cell degranulation, and mast cell granules (MCG), which contain a small amount of endogenous peroxidase activity, are toxic to tumor cells when combined with H2O2 and iodide. This toxicity is greatly increased by binding eosinophil peroxidase (EPO) to the MCG surface. Each component of the mast cell, MCG, or MCG-EPO system was required and toxicity was inhibited by the addition of the hemeprotein inhibitors azide or aminotriazole, which is compatible with a requirement for peroxidase in the cytotoxic reaction. A sequence of reactions is proposed in which mast cells, stimulated to release their granules by H2O2 generated by adjacent phagocytes, react with H2O2 and a halide to damage tumor cells. EPO release from eosinophils may contribute to this sequence of reactions, both by stimulation of H2O2-induced mast cell secretion and by combination with MCG to form a complex with augmented tumoricidal activity. These rections may play a role in the host defense against neoplasms.

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