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1.
Nihon Shokakibyo Gakkai Zasshi ; 121(8): 695-706, 2024.
Article in Japanese | MEDLINE | ID: mdl-39135230

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 vaccine has contributed to infection control and the prevention of complications due to coronavirus disease 2019 (COVID-19). Conversely, the COVID-19 vaccine has been associated with adverse effects due to liver injury caused by autoimmunity or drugs. To date, Japanese journals have only published five reports of autoimmune liver damage associated with the COVID-19 vaccination. Although the pathogenic mechanism has not yet been fully elucidated, corticosteroids or azathioprine have shown effectiveness in certain patients. However, there have been cases of liver injury resulting in deaths. Here, we encountered three patients who developed autoimmune hepatitis (AIH) within 10 days following vaccination. All three patients were treated with prednisolone (PSL) and achieved remission. However, the serum alanine aminotransferase levels in all cases were observed to either increase or cease to improve during the therapeutic course before PSL administration. It is therefore imperative to closely monitor liver injury after the COVID-19 vaccination. In cases where AIH is suspected and a recurrence of liver dysfunction occurs, PSL may be administered. Future considerations should not only encompass the underlying mechanism by which autoimmunity contributes to the development of liver injury following COVID-19 vaccination but also the optimal treatment period for PSL and the long-term prognosis of AIH after COVID-19 vaccination.


Subject(s)
COVID-19 Vaccines , Hepatitis, Autoimmune , Prednisolone , Recurrence , Humans , Hepatitis, Autoimmune/etiology , COVID-19 Vaccines/adverse effects , Female , Male , Prednisolone/administration & dosage , Prednisolone/therapeutic use , Middle Aged , Aged , COVID-19/prevention & control , Vaccination/adverse effects
2.
Intern Med ; 62(21): 3151-3156, 2023 Nov 01.
Article in English | MEDLINE | ID: mdl-36927965

ABSTRACT

A woman in her 70s presented with gallbladder carcinoma with liver metastases and peritoneal dissemination. After standard chemotherapy failed, a liver biopsy was performed. A FoundationOne CDx analysis showed that the tumor mutational burden (TMB) was high (34 mutations/megabase). Treatment with pembrolizumab, which is an immune checkpoint inhibitor (ICI), resulted in a partial response, and there were no significant immune-related adverse events. According to recently published reports, the frequency of TMB-high biliary tract cancer (BTC) is 3.4-4%, which makes it extremely rare. In conclusion, ICIs may be effective in patients with TMB-high BTC.


Subject(s)
Carcinoma , Gallbladder Neoplasms , Lung Neoplasms , Female , Humans , Gallbladder Neoplasms/drug therapy , Gallbladder Neoplasms/genetics , Mutation/genetics , Antibodies, Monoclonal, Humanized/therapeutic use , Lung Neoplasms/drug therapy , Biomarkers, Tumor
3.
Oncology ; 99(4): 203-214, 2021.
Article in English | MEDLINE | ID: mdl-33279908

ABSTRACT

AIM: The aim of this retrospective study was to investigate the efficacy and safety of ramucirumab treatment under real-world conditions and to clarify the role of albumin-bilirubin (ALBI) score in predicting outcomes. METHODS: Between June 2019 and May 2020, a total of 16 patients with advanced hepatocellular carcinoma (HCC) treated with ramucirumab in Gunma Saiseikai Maebashi Hospital and its affiliated hospitals was included. RESULTS: The median age was 71 (interquartile range [IQR] 65-74) years old, and 12 patients (75.0%) were male. The modified ALBI (mALBI) grade was 1, 2a, and 2b at baseline in 4 (25.0%), 3 (18.8%), and 9 patients (56.3%), respectively. The Barcelona Clinic Liver Cancer stage was intermediate and advanced stage in 1 (6.3%) and 15 patients (93.8%), respectively. The serum α-fetoprotein at baseline was 4,911 (IQR 2,091-17,377) ng/mL. The disease control rate in patients with mALBI grade1 + 2a was significantly higher than in those with mALBI grade 2b (100 vs. 28.6%, p = 0.028). The patients with mALBI grade 1 + 2a had a significantly better overall survival (OS) and longer progression-free survival (PFS) than those with mALBI grade 2b (median OS 6.7 vs. 3.0 months; p = 0.036, median PFS 7.5 vs. 1.4 months; p = 0.002). The number of cycles of ramucirumab treatment was significantly correlated with the ALBI score (r = -0.452, p = 0.030). The patients with mALBI grade 1 + 2a showed a low incidence of adverse events (AEs) and discontinuation due to AEs. CONCLUSIONS: Advanced HCC patients with mALBI grade 1 + 2a may be a good indication for ramucirumab treatment.


Subject(s)
Antibodies, Monoclonal, Humanized/adverse effects , Antineoplastic Agents/adverse effects , Bilirubin/blood , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Serum Albumin, Human/analysis , Aged , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/epidemiology , Carcinoma, Hepatocellular/pathology , Female , Humans , Japan/epidemiology , Liver Function Tests , Liver Neoplasms/blood , Liver Neoplasms/epidemiology , Liver Neoplasms/pathology , Male , Middle Aged , Neoplasm Staging , Prognosis , Progression-Free Survival , Retrospective Studies , alpha-Fetoproteins/analysis , Ramucirumab
4.
Intern Med ; 58(13): 1835-1844, 2019 Jul 01.
Article in English | MEDLINE | ID: mdl-30918170

ABSTRACT

Objective The purpose of this multicenter retrospective study was to investigate the impact of the prognostic nutritional index (PNI) on the survival of Japanese patients with hepatocellular carcinoma (HCC) treated with sorafenib. Methods A total of 178 HCC patients from May 2009 to December 2015 at our affiliated hospitals was included in this study. The PNI was calculated as follows: 10×serum albumin (g/dL) +0.005×total lymphocyte count (per mm3). The patients were divided into two groups according to the cut-off value of the PNI and as calculated by a receiver operating characteristic curve analysis. Results The optimum cut-off value of the PNI was set at 46.8. We defined the 33 patients with a PNI≥46.8 as the PNI-high group and the 145 patients with a PNI<46.8 as the PNI-low group. The response rate was 20.0% in the PNI-high group and 8.1% in the PNI-low group, without any statistically significance (p=0.09). The duration of sorafenib therapy and the overall survival in the PNI-high group were significantly better than those in the PNI-low group. The PNI-high group was thus found to be a predictive factor associated with the duration of sorafenib therapy [hazard ratio (HR) 0.58; 95% confidence interval (CI) 0.39-0.87, p=0.008] and overall survival (HR 0.62; 95% CI 0.39-0.99, p=0.046) in a multivariate analysis. Conclusion The PNI is a simple and useful marker for predicting the survival of patients with HCC treated with sorafenib.


Subject(s)
Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/mortality , Liver Neoplasms/drug therapy , Liver Neoplasms/mortality , Lymphocyte Count , Serum Albumin/analysis , Sorafenib/therapeutic use , Aged , Female , Humans , Japan , Male , Middle Aged , Multivariate Analysis , Nutrition Assessment , Nutritional Status , Predictive Value of Tests , Prognosis , Proportional Hazards Models , Retrospective Studies
7.
Nihon Shokakibyo Gakkai Zasshi ; 112(5): 863-70, 2015 May.
Article in Japanese | MEDLINE | ID: mdl-25947022

ABSTRACT

A 63-year-old woman with abdominal pain was referred to our hospital. Her pancreatic enzymes were elevated, and an abdominal computed tomography (CT) scan showed an enlarged pancreas, consistent with pancreatitis, and gas collection containing an impacted stone adjacent to Vater's papilla. This finding raised the suspicion of a duodenal diverticulum. A subsequent ERCP showed a juxtapapillary duodenal diverticulum (JPDD) filled with calculi and pus. The pancreatitis improved with 2 weeks of conservative treatment. Subsequently, the patient underwent resection of the uterus and bilateral adnexa to remove a large ovarian cyst that was also identified on the admission CT scan. On the third postoperative day, she developed abdominal pain and vomiting. CT revealed small bowel obstruction caused by an enterolith expelled from JPDD. Enterotomy was performed to remove the stone. To our knowledge, only three similar cases have been previously reported in Japan.


Subject(s)
Abdominal Pain/etiology , Diverticulum/complications , Ileus/complications , Jejunal Diseases/complications , Pancreatitis/complications , Diverticulum/diagnostic imaging , Diverticulum/therapy , Female , Humans , Ileus/diagnostic imaging , Ileus/therapy , Jejunal Diseases/diagnostic imaging , Jejunal Diseases/therapy , Middle Aged , Pancreatitis/diagnostic imaging , Tomography, X-Ray Computed
8.
Intern Med ; 53(22): 2601-4, 2014.
Article in English | MEDLINE | ID: mdl-25400182

ABSTRACT

A 13-year-old boy was brought to our hospital after recovering from ventricular fibrillation that occurred after an episode of chest pain during training with his soccer team. Subsequent 64-slice multidetector computed tomography revealed the left coronary artery arising from the right sinus of Valsalva, which coursed between the ascending aorta and root of the main pulmonary artery. Surgical correction including unroofing of the left coronary ostium and pulmonary artery translocation was performed successfully. One year later, he remained asymptomatic and was back on his soccer team.


Subject(s)
Coronary Vessel Anomalies/diagnosis , Coronary Vessel Anomalies/surgery , Death, Sudden, Cardiac/etiology , Sinus of Valsalva/abnormalities , Adolescent , Aorta , Cardiac Surgical Procedures , Chest Pain/diagnostic imaging , Coronary Vessel Anomalies/diagnostic imaging , Humans , Male , Multidetector Computed Tomography , Pulmonary Artery/diagnostic imaging , Soccer
9.
J Gastrointestin Liver Dis ; 20(4): 435-8, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22187712

ABSTRACT

Endoscopic hemostasis is a useful treatment modality for gastric ulcer bleeding. However, it is sometimes difficult to achieve hemostasis in cases with arterial bleeding, especially those complicated with vascular abnormalities. We describe a case with gastric ulcer bleeding from a variant left gastric artery accompanied by congenital absence of the splenic artery. A 50-year-old female was admitted to our hospital with dizziness and tarry stools. Upper gastrointestinal endoscopy revealed bleeding from a gastric ulcer, and endoscopic hemostasis by endoscopic clipping was carried out. Computed tomography and abdominal angiography revealed the variant left gastric artery running below the gastric ulcer. In spite of endoscopic hemostasis and medication, re-bleeding from the gastric ulcer occurred. A transcatheter coil embolization for the variant left gastric artery was performed and successfully achieved hemostasis. This case was accompanied by congenital absence of the splenic artery, which is an extremely rare condition. We herein describe this rare case and review previously reported cases.


Subject(s)
Embolization, Therapeutic , Peptic Ulcer Hemorrhage/therapy , Splenic Artery/abnormalities , Stomach Ulcer/complications , Stomach/blood supply , Vascular Malformations/complications , Endoscopy, Gastrointestinal , Female , Hemostasis, Endoscopic , Humans , Middle Aged , Peptic Ulcer Hemorrhage/diagnosis , Peptic Ulcer Hemorrhage/etiology , Recurrence , Splenic Artery/diagnostic imaging , Stomach Ulcer/diagnosis , Tomography, X-Ray Computed , Treatment Outcome , Vascular Malformations/diagnosis
10.
Fukushima J Med Sci ; 52(2): 87-102, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17427760

ABSTRACT

Ventricular fibrillation (VF) is most frequent in the very early phase in acute coronary occlusion, and is triggered by the re-entrant mechanism in this phase. An inhomogeneous conduction in the ischemic myocardium would be substrates for re-entry. The aim of this study was to examine the relationship between the severity of irregularities of the QRS complex and VF. Eleven pigs were analyzed, and the heart was fixed in the pericardial cradle. Ag-AgCl bipolar electrodes were fixed on the epicardium in ischemic and non-ischemic regions. The proximal portion of the left anterior descending coronary artery was occluded for one hour. Electrocardiograms (ECGs) were continuously recorded on a magnetic tape, and wavelet analysis was performed on signal-averaged ECG (25 beats) every 60 sec after the experiment. The number of local maxima (N) and the duration between the first and the last local maximum (D) were automatically measured. N and D significantly increased in the ischemic area, but not in the non-ischemic area. N and D increased approximately twofold just before the occurrence of VF in 8 fibrillated pigs (p<0.01, each). There were significant positive linear relationships between the rate of increase in N and D to VF and basal heart rate before coronary occlusion (r=0.90, p <0.01 in N, r=0.84, p <0.01 in D at 160 Hz). These results suggest that there would be a threshold inhomogeneous conduction for the occurrence of VF and an increase in heart rate would accelerate the inhomogeneous conduction in acute myocardial ischemia.


Subject(s)
Electrocardiography , Heart Conduction System/physiopathology , Myocardial Ischemia/physiopathology , Ventricular Fibrillation/etiology , Animals , Female , Heart Rate , Male , Swine , Ventricular Fibrillation/physiopathology
11.
Arterioscler Thromb Vasc Biol ; 25(12): 2548-53, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16195476

ABSTRACT

BACKGROUND: Flow-induced regulation of endothelial NO synthase (eNOS) depends on integrin signaling and tyrosine kinase activation. Integrins cluster in focal adhesion complexes, where the extracellular matrix is connected to the cytoskeleton and where focal adhesion kinase (FAK) is located. FAK plays a central role in integrin signaling and Src activation. Accordingly, we hypothesized that FAK plays an important role in flow-induced dilation (FID). METHODS AND RESULTS: To inactivate FAK-dependent signaling, anti-FAK, phosphospecific (Tyr397) antibody (FAKab), which binds against the FAK autophosphorylation site, was incorporated into endothelium of rat coronary arterioles using liposomal transfection. The responses to flow, acetylcholine (Ach), or the NO donor MAHAMANONOate (NOC-9) were observed before and after FAKab. In control and vehicles (denatured antibody or transfecting reagent alone), flow produced progressive dilation to a maximal value of 35% increase in diameter, which was inhibited by Nomega-nitro-L-arginine methyl ester (L-NAME). However, FAKab prevented FID (P<0.01 versus control). Combined treatment with FAKab and L-NAME did not produce inhibition greater than FAKab alone. FAKab did not blunt Ach- or NOC-9-induced dilation. Western analysis demonstrated that FAKab prevented flow-induced phosphorylation of FAK (pY397-FAK), Akt (pS473-Akt), and eNOS (pS1179-eNOS). CONCLUSIONS: Our study demonstrates the pivotal role of FAK in NO-mediated FID. Inhibition of FAK signaling with FAKab impaired FID and phosphorylation of Akt and eNOS. Our data suggest that the activation of FAK is central to the mechanotransduction of FID via regulation of activation of Akt and eNOS.


Subject(s)
Coronary Circulation/physiology , Coronary Vessels/enzymology , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Vasodilation/physiology , Animals , Arterioles/enzymology , Enzyme Inhibitors/pharmacology , Focal Adhesion Protein-Tyrosine Kinases/antagonists & inhibitors , In Vitro Techniques , Male , Nitric Oxide/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type III/metabolism , Phosphorylation , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Wistar , Signal Transduction/physiology
12.
Arterioscler Thromb Vasc Biol ; 25(9): 1831-6, 2005 Sep.
Article in English | MEDLINE | ID: mdl-15994438

ABSTRACT

BACKGROUND: Rho and its effector Rho-kinase/ROCK mediate cytoskeletal reorganization as well as smooth muscle contraction. Recent studies indicate that Rho and ROCK are critically involved in vascular remodeling. Here, we tested the hypothesis that Rho/ROCK are critically involved in angiotensin II (Ang II)-induced migration of vascular smooth muscle cells (VSMCs) by mediating a specific signal cross-talk. METHODS AND RESULTS: Immunoblotting demonstrated that Ang II stimulated phosphorylation of a ROCK substrate, regulatory myosin phosphatase targeting subunit (MYPT)-1. Phosphorylation of MYPT-1 as well as migration of VSMCs induced by Ang II was inhibited by dominant-negative Rho (dnRho) or ROCK inhibitor, Y27632. Ang II-induced c-Jun NH2-terminal kinase (JNK) activation, but extracellular signal-regulated kinase (ERK) activation was not mediated through Rho/ROCK. Thus, infection of adenovirus encoding dnJNK inhibited VSMC migration by Ang II. We have further demonstrated that the Rho/ROCK activation by Ang II requires protein kinase C-delta (PKCdelta) and proline-rich tyrosine kinase 2 (PYK2) activation, but not epidermal growth factor receptor transactivation. Also, VSMCs express PDZ-Rho guanine nucleotide exchange factor (GEF) and Ang II stimulated PYK2 association with tyrosine phosphorylated PDZ-RhoGEF. CONCLUSIONS: PKCdelta/PYK2-dependent Rho/ROCK activation through PDZ-RhoGEF mediates Ang II-induced VSMC migration via JNK activation in VSMCs, providing a novel mechanistic role of the Rho/ROCK cascade that is involved in vascular remodeling.


Subject(s)
Cell Movement/physiology , JNK Mitogen-Activated Protein Kinases/metabolism , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/metabolism , Protein Serine-Threonine Kinases/metabolism , rho GTP-Binding Proteins/metabolism , Adenoviridae/genetics , Angiotensin II/pharmacology , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/pathology , Cell Movement/drug effects , Cells, Cultured , Focal Adhesion Kinase 2/genetics , Focal Adhesion Kinase 2/metabolism , Gene Expression , Guanine Nucleotide Exchange Factors/metabolism , Intracellular Signaling Peptides and Proteins , Muscle, Smooth, Vascular/drug effects , Protein Kinase C-delta/metabolism , Receptor Cross-Talk/physiology , Rho Guanine Nucleotide Exchange Factors , Vasoconstrictor Agents/pharmacology , rho GTP-Binding Proteins/genetics , rho-Associated Kinases
13.
Am J Physiol Heart Circ Physiol ; 288(5): H2088-92, 2005 May.
Article in English | MEDLINE | ID: mdl-15637126

ABSTRACT

Alpha-adrenergic vasoconstriction in the coronary circulation is mediated through alpha-adrenoceptors on cardiac myocytes and subsequent release of endothelin, a very potent, long-lasting vasoconstrictor. Recent studies found that adult cardiac myocytes do not express the preproendothelin gene. Thus we hypothesized that alpha-adrenoceptor stimulation on the cardiac myocytes results in the production of an endothelin-releasing factor, which stimulates the coronary vasculature to produce endothelin. We tested this hypothesis by using an in vitro model in which isolated adult rat cardiac myocytes can be stimulated with an alpha-adrenoceptor agonist (phenylephrine). Their bathing fluid is then transferred to isolated coronary arterioles, and vasoactive responses are measured. To identify the source of endothelin, the endothelin-converting enzyme inhibitor phosphoramidon was added to either the myocytes or the isolated arterioles. Phenylephrine enhanced the vasoconstrictor properties of the myocyte bathing fluid. Administration of phosphoramidon (in either the presence or the absence of phenylephrine) to the myocytes had no effect on the vasoactive properties of the bathing fluid. In contrast, administration of phosphoramidon to the isolated arteriole before administration of the bathing fluid converted vasoconstriction to vasodilation, similar to the effect of the endothelin A receptor antagonist JKC-301, indicating that the endothelin is indeed produced by the coronary vasculature. Administration of the angiotensin type 1 receptor antagonist losartan to the vessel bath enhanced vasodilation to the bathing fluid of the phenylephrine-treated but not control myocytes. In conclusion, during alpha-adrenergic activation cardiac myocytes release a factor, probably angiotensin II, that stimulates the vascular production of endothelin. Although the physiological implications of this mechanism are not obvious, this may represent a protective mechanism that integrates neuronal vasoconstrictor mechanisms with myocardial metabolism, which minimizes periods of both coronary underperfusion and overperfusion.


Subject(s)
Coronary Circulation/physiology , Coronary Vessels/physiology , Endothelin-1/metabolism , Myocytes, Cardiac/metabolism , Vasoconstriction/physiology , Adrenergic alpha-Agonists/pharmacology , Animals , Arterioles/physiology , Male , Microcirculation/physiology , Myocytes, Cardiac/drug effects , Phenylephrine/pharmacology , Rats , Rats, Wistar
14.
Pathol Int ; 53(6): 361-70, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12787310

ABSTRACT

We investigated the diagnostic and prognostic value of p53 expression and proliferative activity, as indicated by the Ki-67, in endoscopic biopsy specimens. Specimens were immunologically stained with p53 and MIB-1 (Ki-67), and the MIB-1/Ki-67 labeling index (LI) was calculated. Classification of adenomas was based on findings of H&E-stained preparations into those with low- or high-grade atypia. Well-differentiated tubular and papillary adenocarcinomas were classified as carcinomas with low- or high-grade atypia. There were significant differences among the control and adenoma patients in MIB-1/Ki-67 LI (P < 0.05). No significant difference was identified between adenomas with high grade atypia and carcinomas with low grade atypia. The p53 expression was negative in all adenomas, but it was positive in 68.2% of carcinomas. The current study demonstrated that p53 protein expression in endoscopic biopsy specimens was of preoperative diagnostic value for carcinoma of the ampulla of Vater. The p53 protein positive tumors had a relatively higher malignant potential than p53 protein negative ones. The MIB-1/Ki-67 LI was useful in differentiating non-tumorous lesions from adenomas and adenomas with low- or high-grade atypia. The MIB-1/Ki-67 LI had a prognostic value because clinicopathological factors of carcinoma of ampulla of Vater correlated with MIB-1/Ki-67 LI.


Subject(s)
Adenocarcinoma/pathology , Adenoma/pathology , Ampulla of Vater/pathology , Common Bile Duct Neoplasms/pathology , Ki-67 Antigen/metabolism , Tumor Suppressor Protein p53/metabolism , Adenocarcinoma/metabolism , Adenocarcinoma/surgery , Adenoma/metabolism , Adenoma/surgery , Aged , Biomarkers, Tumor/metabolism , Biopsy , Common Bile Duct Neoplasms/metabolism , Common Bile Duct Neoplasms/surgery , Endoscopy, Gastrointestinal , Female , Humans , Immunoenzyme Techniques , Male , Neoplasm Recurrence, Local , Neoplasm Staging , Prognosis
16.
J Biol Chem ; 277(47): 44695-700, 2002 Nov 22.
Article in English | MEDLINE | ID: mdl-12226102

ABSTRACT

Reactive oxygen species are involved in the mitogenic signal transduction cascades initiated by several growth factors and play a critical role in mediating cardiovascular diseases. Interestingly, H(2)O(2) induces tyrosine phosphorylation and trans-activation of the platelet-derived growth factor receptor and the epidermal growth factor receptor in many cell lines including vascular smooth muscle cells. To investigate the molecular mechanism by which reactive oxygen species contribute to vascular diseases, we have examined a signal transduction cascade involved in H(2)O(2)-induced platelet-derived growth factor receptor activation in vascular smooth muscle cells. We found that H(2)O(2) induced a ligand-independent phosphorylation of the platelet-derived growth factor-beta receptor at Tyr(1021), a phospholipase C-gamma binding site, involving the requirement of protein kinase C-delta and c-Src that is distinct from a ligand-dependent autophosphorylation. Also, H(2)O(2) induced the association of protein kinase C-delta with the platelet-derived growth factor-beta receptor and c-Src in vascular smooth muscle cells. These findings will provide new mechanistic insights by which enhanced reactive oxygen species production in vascular smooth muscle cells induces unique alleys of signal transduction distinct from those induced by endogenous ligands leading to an abnormal vascular remodeling process.


Subject(s)
Isoenzymes/metabolism , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , Reactive Oxygen Species/metabolism , Receptor, Platelet-Derived Growth Factor beta/metabolism , Transcriptional Activation , Acetophenones/pharmacology , Angiogenesis Inducing Agents/pharmacology , Animals , Becaplermin , Benzopyrans/pharmacology , CSK Tyrosine-Protein Kinase , Cells, Cultured , Enzyme Inhibitors/pharmacology , Humans , Hydrogen Peroxide/pharmacology , Isoenzymes/antagonists & inhibitors , Ligands , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/metabolism , Oxidants/pharmacology , Oxidation-Reduction , Phosphorylation , Platelet-Derived Growth Factor/antagonists & inhibitors , Platelet-Derived Growth Factor/pharmacology , Protein Kinase C/antagonists & inhibitors , Protein Kinase C-delta , Protein-Tyrosine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins c-sis , Pyrimidines/pharmacology , Rats , Rats, Sprague-Dawley , Tyrosine/metabolism , Tyrphostins/pharmacology , src-Family Kinases
17.
Biochem Biophys Res Commun ; 294(5): 1023-9, 2002 Jun 28.
Article in English | MEDLINE | ID: mdl-12074579

ABSTRACT

In vascular smooth muscle cells (VSMCs), angiotensin II (AngII) induces transactivation of the EGF receptor (EGFR) which involves a metalloprotease that stimulates processing of heparin-binding EGF from its precursor. However, the identity and pharmacological sensitivity of the metalloprotease remain unclear. Here, we screened the effects of several metalloprotease inhibitors on AngII-induced EGFR transactivation in VSMCs. We found that an N-phenylsulfonyl-hydroxamic acid derivative [2R-[(4-biphenylsulfonyl)amino]-N-hydroxy-3-phenylpropinamide] (BiPS), previously known as matrix metalloprotease (MMP)-2/9 inhibitor, markedly inhibited AngII-induced EGFR transactivation, whereas the MMP-2 or -9 inhibition by other MMP inhibitors failed to block the transactivation. BiPS markedly inhibited AngII-induced ERK activation and protein synthesis without affecting AngII-induced intracellular Ca2+ elevation. VSMC migration induced by AngII was also inhibited not only by an EGFR inhibitor but also by BiPS. Thus, BiPS is a specific candidate to block AngII-induced EGFR transactivation and subsequent growth and migration of VSMCs, suggesting its potency to prevent vascular remodeling.


Subject(s)
Angiotensin II/antagonists & inhibitors , ErbB Receptors/metabolism , Hydroxamic Acids/pharmacology , Matrix Metalloproteinase Inhibitors , Muscle, Smooth, Vascular/drug effects , Protease Inhibitors/pharmacology , Animals , Cell Division/drug effects , Cell Movement/drug effects , Cells, Cultured , Hydroxamic Acids/chemistry , Male , Mitogen-Activated Protein Kinases/metabolism , Muscle, Smooth, Vascular/enzymology , Muscle, Smooth, Vascular/physiology , Protease Inhibitors/chemistry , Rats , Rats, Sprague-Dawley
18.
Eur J Pharmacol ; 443(1-3): 47-50, 2002 May 17.
Article in English | MEDLINE | ID: mdl-12044791

ABSTRACT

Angiotensin II activates three major mitogen-activated protein kinases (MAPK) in vascular smooth muscle cells. Although other angiotensin II-induced MAPKs activation require transactivation of a growth factor receptor, the detailed mechanism by which angiotensin II activates c-Jun NH(2)-terminal kinase (JNK) remains unclear. Here, an immunosuppressant, cyclosporin A but not FK506, selectively inhibited angiotensin II-induced JNK activation in vascular smooth muscle cells. However, cyclosporin A had no inhibitory effect on angiotensin II-induced protein synthesis. Thus, angiotensin II-induced JNK activation but not protein synthesis is mediated by a mechanism sensitive to cyclosporin A, which is independent from calcineurin in vascular smooth muscle cells.


Subject(s)
Angiotensin II/pharmacology , Cyclosporine/pharmacology , Immunosuppressive Agents/pharmacology , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Muscle, Smooth, Vascular/drug effects , Protein Biosynthesis , Angiotensin II/metabolism , Animals , Anisomycin/pharmacology , Aorta, Thoracic , Cells, Cultured , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , JNK Mitogen-Activated Protein Kinases , Leucine/metabolism , Mitogen-Activated Protein Kinases/metabolism , Muscle, Smooth, Vascular/metabolism , Phosphorylation , Protein Synthesis Inhibitors/pharmacology , Rats , Rats, Sprague-Dawley , Sulfonamides/pharmacology , Tacrolimus/pharmacology , p38 Mitogen-Activated Protein Kinases
19.
Mol Endocrinol ; 16(2): 367-77, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11818507

ABSTRACT

In vascular smooth muscle cells, angiotensin II (AngII) stimulates association of its G protein-coupled AngII type 1 (AT(1)) receptor with Janus kinase 2 (JAK2), resulting in the activation of signal transducer and activator of transcription proteins. Although the association and activation of subsequent signal transducer and activator of transcription proteins appear to prerequire JAK2 activation, the signaling mechanism by which the AT(1) receptor activates JAK2 remains uncertain. Here, we have examined the signaling mechanism required for JAK2 activation by AngII in vascular smooth muscle cells. We found that AngII, through the AT(1) receptor, rapidly stimulated JAK2 phosphorylation at Tyr(1007/1008), the critical sites for the kinase activation. By using selective agonists and inhibitors, we demonstrated that PLC and its derived signaling molecules, phosphatidylinositol triphosphate/Ca(2+) and diacylglycerol/PKC, were essential for AngII-induced JAK2 phosphorylation. The PKC isoform required for JAK2 activation appears to be PKCdelta since a selective PKCdelta but not PKCalpha/beta inhibitor and dominant-negative PKCdelta overexpression inhibited JAK2 activation. We further examined a link between JAK2 and a Ca(2+)/PKC-sensitive tyrosine kinase, PYK2. We found that PYK2 activation by AngII requires PKCdelta, and that PYK2 associates with JAK2 constitutively. Moreover, transfection of two distinct PYK2 dominant-negative mutants markedly inhibited AngII-induced JAK2 activation. From these data we conclude that AT(1)-derived signaling molecules, specifically Ca(2+) and PKCdelta, participate in AngII-induced JAK2 activation through PYK2. These data provide a new mechanistic insight by which the hormone AngII exerts its cytokine-like actions in mediating vascular remodeling.


Subject(s)
Angiotensin II/pharmacology , Calcium/pharmacology , Isoenzymes/metabolism , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins , Animals , Cells, Cultured , Enzyme Activation/drug effects , Focal Adhesion Kinase 2 , Immunohistochemistry , Isoenzymes/antagonists & inhibitors , Janus Kinase 2 , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/enzymology , Muscle, Smooth, Vascular/metabolism , Phospholipid Ethers/pharmacology , Phosphorylation/drug effects , Phosphotyrosine/metabolism , Protein Kinase C/antagonists & inhibitors , Protein Kinase C-delta , Protein Transport/drug effects , Rats , Rats, Sprague-Dawley , Receptor, Angiotensin, Type 1 , Receptors, Angiotensin/metabolism , Signal Transduction/drug effects , Transfection , Type C Phospholipases/antagonists & inhibitors , Type C Phospholipases/metabolism
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