• Journal of Life Science
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• v.17 no.3 s.83
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• pp.350-355
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• 2007

The rat RBL-2H3 mast cells contain various Src-family kinases. Previous reports with this cell line indicated that Lyn activation is an important initial signaling for the activation of the cells. However, the role and location of other Src-family kinase isoforms which are expressed in the cells are not clear. In this study, we now show that isoforms of Src-family kinases, Lyn, fyn, Fgr, c-Src, and Yes are differentially expressed and located differently in the cells as indicated by RT-PCR, immunoblotting analysis, and confocal microscopy. Lyn and Fgr were located on plasma membrane but on the other hand c-Src and Yes were located on intracellular organelle. All of Src-family kinases were cloned and overexpressed for investigating the roles of the isoforms. Overexpression of Fyn and Fgr, not Lyn and c-Src, stimulated Ag-induced degranulation in the cells. Our findings strongly suggest for the first time that each of Src-family kinase isoform can regulate differentially $Fc{\varepsilon}RI$-mediated signaling in RBL-2H3 mast cells.

• YAKHAK HOEJI
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• v.52 no.5
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• pp.370-375
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• 2008

In this study, the anti-allergic activity and mechanim of Salviae radix (SR) were investigated. The ethanol extract of SR showed significant inhibitory effect on degranulation from antigen-stimulated mast cells and it also inhibited the expression and secretion of TNF-${\alpha}$ and IL-4 in antigen-stimulated RBL-2H3 cells. In the mast cell-mediated local animal allergy model, it suppressed the passive cutaneous anaphylaxis in a dose-dependent manner. As its mechanism of action, SR inhibited the activating phosphorylation of Syk, a downstream signaling molecule of Src-family kinase, for the activation of mast cells. The results of the study indicate that the anti-allergic activity of SR is mediated by the inhibition of Src-family kinase in mast cells.

• Parasites, Hosts and Diseases
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• v.48 no.4
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• pp.285-290
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• 2010

Tyrosine kinases are one of the most important regulators for intracellular signal transduction related to inflammatory responses. However, there are no reports describing the effects of tyrosine kinases on neutrophil apoptosis induced by Entamoeba histolytica, In this study, isolated human neutrophils from peripheral blood were incubated with live trophozoites in the presence or absence of tyrosine kinase inhibitors. Entamoeba-induced receptor shedding of CD16 and PS externalization in neutrophils were inhibited by pre-incubation of neutrophils with the broad-spectrum tyrosine kinase inhibitor genistein or the Src family kinase inhibitor PP2. Entamoeba-induced ROS production was also inhibited by genistein or PP2, Moreover, genistein and PP2 blocked the phosphorylation of ERK and p38 MAPK in neutrophils induced by E. histolytica. These results suggest that Src tyrosine kinases may participate in the signaling event for ROS-dependent activation of MAPKs during neutrophil apoptosis induced by E. histolytica.

• Molecules and Cells
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• v.26 no.4
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• pp.329-337
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• 2008

Src-family kinases are critically involved in the control of cytoskeleton organization and in the generation of integrin-dependent signaling responses, inducing tyrosine phosphorylation of many signaling and cytoskeletal proteins. Activity of the Src family of tyrosine kinases is tightly controlled by inhibitory phosphorylation of a carboxy-terminal tyrosine residue, inducing an inactive conformation through binding with its SH2 domain. Dephosphorylation of C-ter tyrosine, as well as its deletion of substitution with phenylalanine in oncogenic Src kinases, leads to autophosphorylation at a tyrosine in the activation loop, thereby leading to enhanced Src activity. Beside this phophorylation/dephosphorylation circuitry, cysteine oxidation has been recently reported as a further mechanism of enzyme activation. Mounting evidence describes Src activation via its redox regulation as a key outcome in several circumstances, including growth factor and cytokines signaling, integrin-mediated cell adhesion and motility, membrane receptor cross-talk as well in cell transformation and tumor progression. Among the plethora of data involving Src kinase in physiological and pathophysiological processes, this review will give emphasis to the redox component of the regulation of this master kinase.

• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.41-51
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• 2021

Src family kinases (SFKs), an important group of non-receptor tyrosine kinases, are suggested to be excessively activated during various types of tissue fibrosis. The present study investigated the effect of KF-1607, an orally active and a newly synthesized Src kinase inhibitor (SKI) with proposed low toxicity, in preventing the progression of renal interstitial fibrosis. Unilateral ureteral obstruction (UUO) surgery was performed in 6-week-old male C57BL/6 mice to induce renal interstitial fibrosis. Either KF-1607 (30 mg/kg, oral gavage) or PP2 (2 mg/kg, intraperitoneal injection), a common experimental SKI, was administered to mice for seven days, started one day prior to surgery. UUO injury-induced SFK expression, including Src, Fyn, and Lyn kinase. SFK inhibition by KF-1607 prevented the progression of tubular injury in UUO mice, as indicated by decreases in albuminuria, urinary KIM-1 excretion, and kidney NGAL protein expression. Renal tubulointerstitial fibrosis was attenuated in response to KF-1607, as shown by decreases in α-SMA, collagen I and IV protein expression, along with reduced Masson's trichrome and collagen-I staining in kidneys. KF-1607 also inhibited inflammation in the UUO kidney, as exhibited by reductions in F4/80 positive-staining and protein expression of p-NFκB and ICAM. Importantly, the observed effects of KF-1607 were similar to those of PP2. A new pan Src kinase inhibitor, KF-1607, is a potential pharmaceutical agent to prevent the progression of renal interstitial fibrosis.

• Animal cells and systems
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• v.13 no.4
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• pp.391-397
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• 2009

The house dust mite (Dermatophagoides pteronissinus) is an important factor in triggering allergic diseases. The function of eosinophils, particularly in the production of cytokine or chemokine, is critical in understanding the pathogenesis of inflammatory diseases. In this study, we examined whether D. pteronissinus extract (DpE) induces the expression of monocyte chemotactic protein 1 (MCP-1)/CCL2, IL-8/CXCL8, and IL-6 that mediate in the infiltration and activation of immune cells and in its signaling mechanism in the human eosinophilic cell line, EoL-1. DpE increased the mRNA and protein expression of MCP-1, IL-8, and IL-6 in a time- and dose-dependent course in EoL-1 cells. In our experiments using signal-specific inhibitors, we found that the increased expression of MCP-1, IL-8, and IL-6 due to DpE is associated with Src family tyrosine kinase and protein kinase C $\delta$ (PKC $\delta$). In addition, the activation of extracellular signal-regulated kinase (ERK) is required for MCP-1 and IL-8 expression while p38 mitogen-activated protein kinase (MAPK) is involved in IL-6 expression. DpE induced the phosphorylation of ERK and p38 MAPK. PP2, an inhibitor of Src family tyrosine kinase, and rottlerin, an inhibitor of PKC $\delta$, blocked the activation of ERK and p38 MAPK. DpE induces the activation of ERK and p38 MAPK via Src family tyrosine kinase and PKC $\delta$ for MCP-1, IL-8, or IL-6 production. Increased cytokine release due to the house dust mite and the characterization of its signal transduction may be valuable in understanding the eosinophil-related pathogenic mechanism of inflammatory diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2235-2240
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• 2012

c-Src is one member of non-receptor tyrosine kinase protein family that has over expression and activation in many human cancer cells. It has been shown that c-Src is implicated in various downstream signaling pathways associated with EGFR-dependent signaling such as MAPK and STAT5 pathways. Transactivation of EGFR by c-Src is more effective than EGFR ligands. To inhibit the c-Src expression, we used c-Src antisense oligonucleotide complexed with PAMAM Denderimes. The effect of c-Src antisense oligonucleotide on HT29 cell proliferation was determined by MTT assay. Then, the expression of c-Src, EGFR and the genes related to EGFR-depended signaling with P53 was applied by real time PCR. We used western blot analysis to elucidate the effect of antisense on the level of c-Src protein expression. The results showed, c-Src antisense complexed with PAMAM denderimers has an effective role in decrease of c-Src expression and EGFR-dependent downstream genes.

• BMB Reports
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• v.42 no.1
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• pp.35-40
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• 2009

Protein kinase D2 (PKD2) is a member of the PKD serine/threonine protein kinase family that has been implicated in the regulation of a variety of cellular processes including proliferation, survival, protein trafficking and immune response. In the present study, we report a novel interaction between PKD2 and Lck, a member of the Src tyrosine protein kinase family that is predominantly expressed in T cells. This interaction involved the C-terminal kinase domains of both PKD2 and Lck. Moreover, co-expression of Lck enhanced the tyrosine phosphorylation of PKD2 and increased its kinase activity. Finally, we report that PKD2 enhanced T cell receptor (TCR)-induced nuclear factor of T cell (NFAT) activity in Jurkat T cells. These results suggested that Lck regulated the activity of PKD2 by tyrosine phosphorylation, which in turn may have modulated the physiological functions of PKD2 during TCR-induced T cell activation.

• International Journal of Oral Biology
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• v.39 no.3
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• pp.131-136
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• 2014

Porphyromonas gingivalis is one of the most important periodontal pathogens and has been to known to invade various types of cells, including endothelial cells. The present study investigated the mechanisms involved in the internalization of P. gingivalis in human umbilical vein endothelial cells (HUVEC). P. gingivalis internalization was reduced by clathrin and lipid raft inhibitors, as well as a siRNA knockdown of caveolin-1, a principal molecule of lipid raft-related caveolae. The internalization was also reduced by perturbation of actin rearrangement, while microtubule polymerization was not required. Furthermore, we found that Src kinases are critical for the internalization of P. gingivalis into HUVEC, while neither Rho family GTPases nor phosphatidylinositol 3-kinase are required. Taken together, this study indicated that P. gingivalis internalization into endothelial cells involves clathrin and lipid rafts and requires actin rearrangement associated with Src kinase activation.

• Korean Journal of Medicinal Crop Science
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• v.18 no.6
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• pp.398-404
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• 2010

Complementary and alternative medicines are considered as a promising research field to develop new therapies for various allergic diseases. In this study, we investigated the anti-allergic effect of Agrimonia pilosa Ledeb (AP) by using passive cutaneous anaphylaxis in mice and its mechanism of action in mast cells. The extract of AP reversibly inhibited degranulation in RBL-2H3 cells and bone marrow-derived mast cells (BMMCs). AP also suppressed the passive cutaneous anaphylaxis inducing by IgE and antigen (Ag) in a dose-dependent manner. In the study to find its mechanism of action, AP inhibited the phosphorylation of Syk kinase, a pivotal protein which is regulated by Src-family kinase for activation of mast cells. In addition, AP also suppressed activation of Akt and Erk1/2 that are critical for the production of cytokines in mast cells. The results strongly suggest that AP exerts anti-allergic activity in vitro and in vivo through the inhibition of activation of Syk in mast cells.