scholarly journals Intracellular signaling pathway in dendritic cells and antigen transport pathway in vivo mediated by an OVA@DDAB/PLGA nano-vaccine

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shulan Han ◽  
Wenyan Ma ◽  
Dawei Jiang ◽  
Logan Sutherlin ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Signaling Pathway ◽  
Intracellular Signaling ◽  
Ammonium Bromide ◽  
Transport Pathway ◽  
Antigen Uptake ◽  
Intracellular Signaling Pathway ◽  
Antigen Transport

Abstract Background Poly(D, L-lactic-co-glycolic acid) (PLGA) nanoparticles have potential applications as a vaccine adjuvant and delivery system due to its unique advantages as biodegradability and biocompatibility. Experimental We fabricated cationic solid lipid nanoparticles using PLGA and dimethyl-dioctadecyl-ammonium bromide (DDAB), followed by loading of model antigen OVA (antigen ovalbumin, OVA257-264) to form an OVA@DDAB/PLGA nano-vaccine. And we investigated the intracellular signaling pathway in dendritic cells in vitro and antigen transport pathway and immune response in vivo mediated by an OVA@DDAB/PLGA nano-vaccine. Results In vitro experiments revealed that the antigen uptake of BMDCs after nanovaccine incubation was two times higher than pure OVA or OVA@Al at 12 h. The BMDCs were well activated by p38 MAPK signaling pathway. Furthermore, the nano-vaccine induced antigen escape from lysosome into cytoplasm with 10 times increased cross-presentation activity than those of OVA or OVA@Al. Regarding the transport of antigen into draining lymph nodes (LNs), the nano-vaccine could rapidly transfer antigen to LNs by passive lymphatic drainage and active DC transport. The antigen+ cells in inguinal/popliteal LNs for the nano-vaccine were increased over two folds comparing to OVA@Al and OVA at 12 h. Moreover, the antigen of nano-vaccine stayed in LNs for over 7 days, germinal center formation over two folds higher than those of OVA@Al and OVA. After immunization, the nano-vaccine induced a much higher ratio of IgG2c/IgG1 than OVA@Al. It also effectively activated CD4+ T, CD8+ T and B cells for immune memory with a strong cellular response. Conclusion These results indicated that DDAB/PLGA NP was a potent platform to improve vaccine immunogenicity by p38 signaling pathway in BMDCs, enhancing transport of antigens to LNs, and higher immunity response. Graphical Abstract

scholarly journals Mel1c Mediated Monochromatic Light-Stimulated IGF-I Synthesis through the Intracellular Gαq/PKC/ERK Signaling Pathway

2019 ◽  
Vol 20 (7) ◽  
pp. 1682
Author(s):  
Shujie Ning ◽  
Zixu Wang ◽  
Jing Cao ◽  
Yulan Dong ◽  
Yaoxing Chen
Keyword(s):  
Signaling Pathway ◽  
Intracellular Signaling ◽  
Monochromatic Light ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Erk Signaling ◽  
Sham Operation ◽  
Intracellular Signaling Pathway ◽  
Igf I

Previous studies have demonstrated that monochromatic light affects plasma melatonin (MEL) levels, which in turn regulates hepatic insulin-like growth factor I (IGF-I) secretion via the Mel1c receptor. However, the intracellular signaling pathway initiated by Mel1c remains unclear. In this study, newly hatched broilers, including intact, sham operation, and pinealectomy groups, were exposed to either white (WL), red (RL), green (GL), or blue (BL) light for 14 days. Experiments in vivo showed that GL significantly promoted plasma MEL formation, which was accompanied by an increase in the MEL receptor, Mel1c, as well as phosphorylated extracellular regulated protein kinases (p-ERK1/2), and IGF-I expression in the liver, compared to the other light-treated groups. In contrast, this GL stimulation was attenuated by pinealectomy. Exogenous MEL elevated the hepatocellular IGF-I level, which is consistent with increases in cyclic adenosine monophosphate (cAMP), Gαq, phosphorylated protein kinase C (p-PKC), and p-ERK1/2 expression. However, the Mel1c selective antagonist prazosin suppressed the MEL-induced expression of IGF-I, Gαq, p-PKC, and p-ERK1/2, while the cAMP concentration was barely affected. In addition, pretreatment with Ym254890 (a Gαq inhibitor), Go9863 (a PKC inhibitor), and PD98059 (an ERK1/2 inhibitor) markedly attenuated MEL-stimulated IGF-I expression and p-ERK1/2 activity. These results indicate that Mel1c mediates monochromatic GL-stimulated IGF-I synthesis through intracellular Gαq/PKC/ERK signaling.

scholarly journals Akt Inhibitor Akt-IV Blocks Virus Replication through an Akt-Independent Mechanism

2009 ◽  
Vol 83 (22) ◽  
pp. 11665-11672 ◽  
Author(s):  
Ewan F. Dunn ◽  
Rachel Fearns ◽  
John H. Connor
Keyword(s):  
Signaling Pathway ◽  
Virus Replication ◽  
Intracellular Signaling ◽  
Akt Pathway ◽  
Akt Inhibitor ◽  
Antiviral Compound ◽  
Intracellular Signaling Pathway ◽  
Cytopathic Effects ◽  
Syncytial Virus

ABSTRACT Many viruses activate the phosphatidylinositol 3′-kinase (PI3k)/Akt intracellular signaling pathway to promote viral replication. We have analyzed whether a rapidly replicating rhabdovirus, vesicular stomatitis virus (VSV), requires the PI3k/Akt signaling pathway for its replication. Through the use of chemical inhibitors of PI3k and Akt, we show that VSV replication and cytopathic effects do not require activation of these kinases. Inhibitors that block the activating phosphorylations of Akt at threonine 308 (Thr308) and serine 473 (Ser473) did not inhibit VSV protein expression or the induction of the cytopathic effects of VSV. One compound, Akt inhibitor Akt-IV, inhibited the replication of VSV, respiratory syncytial virus, and vaccinia virus but increased the phosphorylation of Akt at positions Thr308 and Ser473 and did not inhibit Akt kinase activity in vitro. Together, our data suggest that the PI3k/Akt pathway is of limited relevance to the replication of VSV but that Akt inhibitor Akt-IV is a novel broad-spectrum antiviral compound with a mechanism differing from that of its previously reported effect on the PI3k/Akt pathway. Identification of other targets for this compound may define a new approach for blocking virus replication.

Aldosterone inhibits apical NHE3 and HCO3− absorption via a nongenomic ERK-dependent pathway in medullary thick ascending limb

2006 ◽  
Vol 291 (5) ◽  
pp. F1005-F1013 ◽  
Author(s):  
Bruns A. Watts ◽  
Thampi George ◽  
David W. Good
Keyword(s):  
Signaling Pathway ◽  
Intracellular Signaling ◽  
Thick Ascending Limb ◽  
Erk Activation ◽  
Intracellular Signaling Pathway ◽  
Cellular Processes ◽  
Medullary Thick Ascending Limb ◽  
Erk Activity ◽  
Rapid Activation

Although aldosterone influences a variety of cellular processes through nongenomic mechanisms, the significance of nongenomic pathways for aldosterone-induced regulation of epithelial function is not understood. Recently, we demonstrated that aldosterone inhibits transepithelial HCO3− absorption in the medullary thick ascending limb (MTAL) through a nongenomic pathway. This inhibition is mediated through a direct cellular action of aldosterone to inhibit the apical membrane NHE3 Na+/H+ exchanger. The present study was designed to identify the intracellular signaling pathway(s) responsible for this aldosterone-induced transport regulation. In rat MTALs perfused in vitro, addition of 1 nM aldosterone to the bath decreased HCO3− absorption by 30%. This inhibition was not mediated by cAMP/PKA and was not prevented by inhibitors of PKC or PI3-K, pertussis toxin, or rapamycin. The inhibition of HCO3− absorption by aldosterone was largely eliminated by the MEK/ERK inhibitors U-0126 and PD-98059. Aldosterone increased ERK activity 1.8-fold in microdissected MTALs. This ERK activation is rapid (≤5 min) and is blocked by U-0126 or PD-98059 but is unaffected by spironolactone or actinomycin D. Pretreatment with U-0126 to block ERK activation prevented the effect of aldosterone to inhibit apical NHE3. These data demonstrate that aldosterone inhibits NHE3 and HCO3− absorption in the MTAL through rapid activation of the ERK signaling pathway. The results identify NHE3 as a target for nongenomic regulation by aldosterone and establish a role for ERK in the acute regulation of NHE3 and its epithelial absorptive functions.

Bacterial lipopolysaccharide directly induces angiogenesis through TRAF6-mediated activation of NF-κB and c-Jun N-terminal kinase

Blood ◽  
2003 ◽  
Vol 102 (5) ◽  
pp. 1740-1742 ◽  
Author(s):  
Ingrid Pollet ◽  
Christy J. Opina ◽  
Carla Zimmerman ◽  
Kevin G. Leong ◽  
Fred Wong ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Tumor Necrosis Factor Receptor ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Bacterial Lipopolysaccharide ◽  
Intracellular Signaling Pathway ◽  
Necrosis Factor

AbstractThe intracellular pathways by which inflammatory mediators transmit their angiogenic signals is not well studied. The effects of a potent inflammatory mediator, bacterial lipopolysaccharide (LPS), are transmitted through Toll-like receptors (TLRs). A major, although not exclusive, LPS/TLR intracellular signaling pathway is routed through TNF (tumor necrosis factor) receptor associated factor 6 (TRAF6). In this report we demonstrate that LPS directly stimulates endothelial sprouting in vitro. By blocking TRAF6 activity using retroviral expression of a dominant-negative TRAF6 in endothelial cells, we show that TRAF6 is absolutely required for the LPS-initiated angiogenic response in vitro and in vivo. Inhibition of either c-Jun N-terminal kinase (JNK) activity or nuclear factor κB (NF-κB) activity, downstream of TRAF6, is sufficient to inhibit LPS-induced endothelial sprouting. In contrast, only inhibition of NF-κB, but not JNK, activity blocks basic fibroblast growth factor (bFGF)–induced angiogenesis. Our findings thus demonstrate a direct endothelial-stimulatory role of LPS in initiating angiogenesis through activation of TRAF6-dependent signaling pathways.

scholarly journals Search of Allosteric Inhibitors and Associated Proteins of an AKT-like Kinase from Trypanosoma cruzi

2018 ◽  
Vol 19 (12) ◽  
pp. 3951 ◽  
Author(s):  
Rodrigo Ochoa ◽  
Cristian Rocha-Roa ◽  
Marcel Marín-Villa ◽  
Sara Robledo ◽  
Rubén Varela-M
Keyword(s):  
Trypanosoma Cruzi ◽  
Signaling Pathway ◽  
Intracellular Signaling ◽  
Rational Design ◽  
Interaction Network ◽  
Pleckstrin Homology Domain ◽  
Intracellular Signaling Pathway ◽  
Protein Protein Interaction ◽  
Associated Proteins

Proteins associated to the PI3K/AKT/mTOR signaling pathway are widely used targets for cancer treatment, and in recent years they have also been evaluated as putative targets in trypanosomatids parasites, such as Trypanosoma cruzi. Here, we performed a virtual screening approach to find candidates that can bind regions on or near the Pleckstrin homology domain of an AKT-like protein in T. cruzi. The compounds were also evaluated in vitro. The in silico and experimental results allowed us to identify a set of compounds that can potentially alter the intracellular signaling pathway through the AKT-like kinase of the parasite; among them, a derivative of the pyrazolopyridine nucleus with an IC50 of 14.25 ± 1.00 μM against amastigotes of T. cruzi. In addition, we built a protein–protein interaction network of T. cruzi to understand the role of the AKT-like protein in the parasite, and look for additional proteins that can be postulated as possible novel molecular targets for the rational design of compounds against T. cruzi.

ET-1 induces cortical spreading depression via activation of the ETA receptor/phospholipase C pathway in vivo

2004 ◽  
Vol 286 (4) ◽  
pp. H1339-H1346 ◽  
Author(s):  
Jörg Kleeberg ◽  
Gabor C. Petzold ◽  
Sebastian Major ◽  
Ulrich Dirnagl ◽  
Jens P. Dreier
Keyword(s):  
Receptor Antagonist ◽  
Phospholipase C ◽  
Intracellular Signaling ◽  
Neuronal Excitability ◽  
Calcium Waves ◽  
Direct Stimulation ◽  
Intracellular Signaling Pathway ◽  
Receptor Profile

Recently, it has been shown that brain topical superfusion of endothelin (ET)-1 at concentrations around 100 nM induces repetitive cortical spreading depressions (CSDs) in vivo. It has remained unclear whether this effect of ET-1 is related to a primary neuronal/astroglial effect, such as an increase in neuronal excitability or induction of interastroglial calcium waves, or a penumbra-like condition after vasoconstriction. In vitro, ET-1 regulates interastroglial communication via combined activation of ETA and ETB receptors, whereas it induces vasoconstriction via single activation of ETA receptors. We have determined the ET receptor profile and intracellular signaling pathway of ET-1-induced CSDs in vivo. In contrast to the ETB receptor antagonist BQ-788 and concentration dependently, the ETA receptor antagonist BQ-123 completely blocked the occurrence of ET-1-induced CSDs. The ETB receptor antagonist did not increase the efficacy of the ETA receptor antagonist. Direct stimulation of ETB receptors with the selective ETB agonist BQ-3020 did not trigger CSDs. The phospholipase C (PLC) antagonist U-73122 inhibited CSD occurrence in contrast to the protein kinase C inhibitor Gö-6983. Our findings indicate that ET-1 induces CSDs through ETA receptor and PLC activation. We conclude that the induction of interastroglial calcium waves is unlikely the primary cause of ET-1-induced CSDs. On the basis of the receptor profile, likely primary targets of ET-1 mediating CSD are either neurons or vascular smooth muscle cells.

scholarly journals TNF-α-induced protein 8-like 2 negatively regulates the immune function of dendritic cells by suppressing autophagy via the TAK1/JNK pathway in septic mice

2021 ◽  
Vol 12 (11) ◽  
Author(s):  
Shuang-Qing Liu ◽  
Chao Ren ◽  
Ren-Qi Yao ◽  
Yao Wu ◽  
Ying-Yi Luan ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Function ◽  
Signaling Pathway ◽  
Transforming Growth Factor ◽  
Jnk Pathway ◽  
Septic Complications ◽  
Tnf Α ◽  
Autophagic Activity

AbstractTumor necrosis factor (TNF)-α-induced protein 8-like 2 (TIPE2) is a newly discovered negative immunoregulatory protein that is involved in various cellular immune responses to infections. However, the underlying mechanism by which TIPE2 affects the immune function of dendritic cells (DCs) is not yet understood. This study aimed to determine the correlations among DCs TIPE2 expression, autophagic activity and immune function in the context of sepsis. In addition, the signaling pathway by which TIPE2 regulates autophagy in DCs was investigated. We reported for the first time that TIPE2 overexpression (knock-in, KI) exerted an inhibitory effect on autophagy in DCs and markedly suppressed the immune function of DCs upon septic challenge both in vitro and in vivo. In addition, TIPE2 knockout (KO) in DCs significantly enhanced autophagy and improved the immune response of DCs in sepsis. Of note, we found that the transforming growth factor-β (TGF-β)-activated kinase-1 (TAK1)/c-Jun N-terminal kinase (JNK) pathway was inhibited by TIPE2 in DCs, resulting in downregulated autophagic activity. Collectively, these results suggest that TIPE2 can suppress the autophagic activity of DCs by inhibiting the TAK1/JNK signaling pathway and further negatively regulate the immune function of DCs in the development of septic complications.

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