555 research outputs found
The Flavonoid Luteolin Worsens Chemical-Induced Colitis in NF-κBEGFP Transgenic Mice through Blockade of NF-κB-Dependent Protective Molecules
BackgroundThe flavonoid luteolin has anti-inflammatory properties both in vivo and in vitro. However, the impact of luteolin on experimental models of colitis is unknown.Methodology/Principal FindingsTo address the therapeutic impact of luteolin, NF-κBEGFP transgenic mice were fed a chow diet containing 2% luteolin- or isoflavone-free control chow (AIN-76), and acute colitis was induced using 3% dextran sodium sulfate (DSS). Additionally, development of spontaneous colitis was evaluated in IL-10−/−;NF-κBEGFP transgenic mice fed 2% luteolin chow diet or control chow diet. Interestingly, NF-κBEGFP transgenic mice exposed to luteolin showed worse DSS-induced colitis (weight loss, histological scores) compared to control-fed mice, whereas spontaneous colitis in IL-10−/−;NF-κBEGFP mice was significantly attenuated. Macroscopic imaging of live resected colon showed enhanced EGFP expression (NF-κB activity) in luteolin-fed mice as compared to control-fed animals after DSS exposure, while cecal EGFP expression was attenuated in luteolin-fed IL-10−/− mice. Interestingly, confocal microscopy showed that EGFP positive cells were mostly located in the lamina propria and not in the epithelium. Caspase 3 activation was significantly enhanced whereas COX-2 gene expression was reduced in luteolin-fed, DSS-exposed NF-κBEGFP transgenic mice as assessed by Western blot and immunohistochemical analysis. In vitro, luteolin sensitized colonic epithelial HT29 cells to TNFα-induced apoptosis, caspase 3 activation, DNA fragmentation and reduced TNFα-induced C-IAP1, C-IAP2 and COX-2 gene expression.Conclusions/SignificanceWe conclude that while luteolin shows beneficial effects on spontaneous colitis, it aggravates DSS-induced experimental colitis by blocking NF-κB-dependent protective molecules in enterocytes
Epidermal-specific deletion of TC-PTP promotes UVB-induced epidermal cell survival through the regulation of Flk-1/JNK signaling
UVB exposure can contribute to the development of skin cancer by modulating protein tyrosine kinase (PTK) signaling. It has been suggested that UVB radiation increases the ligand-dependent activation of PTKs and induces PTP inactivation. Our recent studies have shown that T-cell protein tyrosine phosphatase (TC-PTP) attenuates skin carcinogenesis induced by chemical regimens, which indicates its critical role in the prevention of skin cancer. In the current work, we report that TC-PTP increases keratinocyte susceptibility to UVB-induced apoptosis via the downregulation of Flk-1/JNK signaling. We showed that loss of TC-PTP led to resistance to UVB-induced apoptosis in vivo epidermis. We established immortalized primary keratinocytes (IPKs) from epidermal-specific TC-PTP-deficient (K14Cre.Ptpn2fl/fl) mice. Immortalized TC-PTP-deficient keratinocytes (TC-PTP/KO IPKs) showed increased cell survival against UVB-induced apoptosis which was concomitant with a UVB-mediated increase in Flk-1 phosphorylation, especially on tyrosine residue 1173. Inhibition of Flk-1 by either its specific inhibitors or siRNA in TC-PTP/KO IPKs reversed this effect and significantly increased cell death after UVB irradiation in comparison with untreated TC-PTP/KO IPKs. Immunoprecipitation analysis using the TC-PTP substrate-trapping mutant TCPTP-D182A indicated that TC-PTP directly interacts with Flk-1 to dephosphorylate it and their interaction was stimulated by UVB. Following UVBmediated Flk-1 activation, the level of JNK phosphorylation was also significantly increased in TC-PTP/KO IPKs compared to control IPKs. Similar to our results with Flk-1, treatment of TC-PTP/KO IPKs with the JNK inhibitor SP600125 significantly increased apoptosis after UVB irradiation, confirming that the effect of TC-PTP on UVB-mediated apoptosis is regulated by Flk-1/JNK signaling. Western blot analysis showed that both phosphorylated Flk-1 and phosphorylated JNK were significantly increased in the epidermis of TC-PTP-deficient mice compared to control mice following UVB. Our results suggest that TC-PTP plays a protective role against UVB-induced keratinocyte cell damage by promoting apoptosis via negative regulation of Flk-1/JNK survival signaling
Preoperative and Postoperative Evaluation of Multiple Giant Coronary Aneurysms by the Use of Coronary CT Angiography with 64-MDCT: A Case of Multiple Giant Coronary Aneurysms Treated with Aneurysmectomy and Coronary Artery Bypass Surgery
A coronary artery aneurysm is an uncommon disorder and is seen as a characteristic dilatation of a localized portion of the coronary artery. Clinical manifestation of a coronary artery aneurysm varies from an asymptomatic presentation to sudden death of a patient. Although coronary aneurysms are typically diagnosed by the use of coronary angiography, a new generation of coronary 64-slice multidetector computed tomography (64-MDCT) scanners have successfully been used for evaluating this abnormality in a noninvasive manner. In the present case, we performed coronary 64-MDCT scanning preoperatively and postoperatively on a patient with multiple giant coronary aneurysms. The use of coronary 64-MDCT may provide an evaluation technique not only for diagnosis but also for follow-up after surgery for this condition
Cordycepin induces apoptosis of human ovarian cancer cells by inhibiting CCL5-mediated Akt/NF-κB signaling pathway
The chemokine, CCL5, is a key mediator for the recruitment of immune cells into tumors and tissues. Akt/NF-κB signaling is significantly activated by CCL5. However, the role of NF-κB inactivation in apoptosis induced by negative regulation of CCL5 remains unclear. Here, we analyzed the effect of cordycepin on NF-κB activity in SKOV-3 cells and found that cordycepin-mediated inhibition of NF-κB signaling induced apoptosis in SKOV-3 cells via the serial activation of caspases. In addition, immune-blotting analysis showed that CCL5 is highly expressed in SKOV-3 cells. In addition to activating caspases, we show that, cordycepin prevents TNF-α-induced increase in CCL5, Akt, NF-κB, and c-FLIPL activation and that CCL5 siRNA could inhibit Akt/NF-κB signaling. Moreover, cordycepin negatively regulated the TNF-α-mediated IκB/NF-κB pathway and c-FLIPL activation to promote JNK phosphorylation, resulting in caspase-3 activation and apoptosis. Also, we show that c-FLIPL is rapidly lost in NF-κB activation-deficient. siRNA mediated c-FLIP inhibition increased JNK. SP600125, a selective JNK inhibitor, downregulated p-JNK expression in cordycepin-treated SKOV-3 cells, leading to suppression of cordycepin-induced apoptosis. Thus, these results indicate that cordycepin inhibits CCL5-mediated Akt/NF-κB signaling, which upregulates caspase-3 activation in SKOV-3 cells, supporting the potential of cordycepin as a therapeutic agent for ovarian cancer
Mesenteric Pseudocyst of the Small Bowel in Gastric Cancer Patient: A Case Report
Mesenteric pseudocyst is rare. This term is used to describe the abdominal cystic mass, without the origin of abdominal organ. We presented a case of mesenteric pseudocyst of the small bowel in a 70-year-old man. Esophago-gastro-duodenoscopy showed a 3.5 cm sized excavated lesion on the posterior wall of angle. Endocopic biopsy confirmed a histologic diagnosis of the poorly differentiated adenocarcinoma, which includes the signet ring cell component. Abdominal computed tomography scan showed a focal mucosal enhancement in the posterior wall of angle of the stomach, a 2.4 cm sized enhancing mass on the distal small bowel loop, without distant metastases or ascites in rectal shelf, and multiple gallbladder stones. The patient underwent subtotal gastrectomy with gastroduodenostomy, segmental resection of the small bowel, and cholecystectomy. The final pathological diagnosis was mesenteric pseudocyst. This is the first case report describing incidentally detected mesenteric pseudocyst of the small bowel in gastric cancer patients
TLR2-induced astrocyte MMP9 activation compromises the blood brain barrier and exacerbates intracerebral hemorrhage in animal models
Background: The innate immune response plays an important role in the pathogenesis of intracerebral hemorrhage (ICH). Recent studies have shown that Toll-like receptor 2 (TLR2) is involved in the innate immune response in various neurological diseases, yet neither its role in ICH nor the mechanisms by which it functions have yet been elucidated. We examined these in this study using a collagenase-induced mouse ICH model with TLR2 knock-out (KO) mice. Results: TLR2 expression was upregulated in the ipsilateral hemorrhagic tissues of the collagenase-injected mice. Brain injury volume and neurological deficits following ICH were reduced in TLR2 KO mice compared to wild-type (WT) control mice. Heterologous blood-transfer experiments show that TLR2 signaling in brain-resident cells, but not leukocytes, contributes to the injury. In our study to elucidate underlying mechanisms, we found that damage to blood-brain barrier (BBB) integrity following ICH was attenuated in TLR2 KO mice compared to WT mice, which may be due to reduced matrix metalloproteinase-9 (MMP9) activation in astrocytes. The reduced BBB damage accompanies decreased neutrophil infiltration and proinflammatory gene expression in the injured brain parenchyma, which may account for the attenuated brain damage in TLR2 KO mice after ICH. Conclusions: TLR2 plays a detrimental role in ICH-induced brain damage by activating MMP9 in astrocytes, compromising BBB, and enhancing neutrophils infiltration and proinflammatory gene expression. © 2015 Min et al.; licensee BioMed Central.1
A Rare Case of Aortic Valve Myxoma: Easy to Confuse With Papillary Fibroelastoma
Myxoma of the aortic valve is an exceedingly uncommon condition. In this article, we report the case of a 72-year-old man with myxoma arising from the aortic valve. We extirpated the mass and repaired the aortic valve with the patient under cardiopulmonary bypass. The postoperative course was uneventful. Histological examination confirmed that the mass was a myxoma
Surgical Management of Left Ventricular Outflow Tract Obstruction after Biventricular Repair of Double Outlet Right Ventricle
Regardless of the preoperative morphology and the type of operation, left ventricular outflow tract obstruction (LVOTO) after biventricular repair of double outlet right ventricle (DORV) may develop. This report presents our 10-yr experience with surgical management of LVOTO after biventricular repair of DORV. Between 1996 and 2006, 15 patients underwent reoperation for subaortic stenosis after biventricular repair of DORV. The mean age at biventricular repair was 23.3±18.3 months (1.1-64.2). Biventricular repairs included tunnel constructions from the left ventricle to the aorta in 14 cases and an arterial switch operation in one. The mean left ventricle-to-aorta peak pressure gradient was 54.0±37.7 mmHg (15-140) after a mean follow-up of 9.5±6.3 yr. We performed extended septoplasty in nine patients and fibromuscular resection in six. There were no early or late mortality. There was one heart block and one aortic valve injury after an extended septoplasty, and two and one after a fibromuscular resection. No patient required reoperation for recurrent subaortic stenosis. The mean pressure gradient was 11.2±11.4 mmHg (0-34) after a mean follow-up of 5.6±2.7 yr. Extended septoplasty is a safe and effective method for the treatment of subaortic stenosis, especially in cases with a long-tunnel shaped LVOTO
Clinical Characteristics of Microscopic Colitis in Korea: Prospective Multicenter Study by KASID
Background/Aims: Microscopic colitis (MC) encompasses collagenous and lymphocytic colitis and is characterized by chronic diarrhea. In cases of MC, colonic mucosae are macroscopically normal, and diagnostic histopathological features are observed only upon microscopic examination. We designed a prospective multicenter study to determine the clinical features, pathological distribution in the colon and prevalence of MC in Korea. Methods: We prospectively enrolled patients having watery diarrhea no more than 3 times a day between March 2008 and February 2009. We obtained patient histories and performed colonoscopies with random biopsies at each colon segment. Results: A total of 100 patients with chronic diarrhea were enrolled for a normal colonoscopy and stool exam. MC was observed in 22 patients (22%) (M:F 1.2:1; mean age, 47.5 years). Of those 22 patients, 18 had lymphocytic colitis and 4 had collagenous colitis. The entire colon was affected in only 3 cases (13.6%), the ascending colon in 6 cases (27.2%), the transverse colon in 3 cases (13.6%), and the left colon in 3 cases (13.6%). More than 2 segments were affected in 7 cases (31.8%). Nonsteroidal anti-inflammatory drug-associated MCs were observed in 4 cases (18.2%), 3 of which showed improved diarrhea symptoms following discontinuation of the medication. Frequently associated symptoms were abdominal pain and weight loss. Autoimmune diseases were observed in 4 cases (18.2%). Half of the 22 patients with MC improved with conservative care by loperamide or probiotics. Conclusions: In a prospective multicenter study of Korean patients with chronic diarrhea, the frequency of MC was found to be approximately 20%, similar to the percentage observed in Western countries. Therefore, the identification of MC is important for the adequate management of Korean patients with chronic diarrhea. (Gut Liver 20115:181-186
Nonimmunity against hepatitis B virus infection in patients newly diagnosed with inflammatory bowel disease
Background/AimsThis study aimed to elucidate the prevalence of hepatitis B virus (HBV) serologic markers in Korean patients newly diagnosed with, but not yet treated for inflammatory bowel disease (IBD).MethodsWe prospectively enrolled 210 patients newly diagnosed with IBD (109 with ulcerative colitis and 101 with Crohn's disease). Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were measured and compared with those of 1,100 sex- and age-matched controls.ResultsThe prevalence of chronic HBV infection (positive HBsAg, positive anti-HBc, and negative anti-HBs results) and past infection (negative HBsAg, positive anti-HBc, and positive or negative anti-HBs results) were not significantly different between the patients and controls (chronic HBV infection: IBD, 3.8% vs. control, 4.9%, P=0.596; past infection: IBD, 26.2% vs. control, 28.8%, P=0.625). The patients with IBD aged <20 years were at a higher susceptibility risk (nonimmune) for HBV infection than the controls (IBD, 41.5% vs. control, 22.4%; P=0.018). In the multivariate analysis, an age of <20 years (P=0.024) and symptom duration of ≥12 months before diagnosis (P=0.027) were identified as independent risk factors for nonimmunity against HBV infection.ConclusionsThe patients newly diagnosed with IBD were susceptible to HBV infection. The frequency of nonimmunity was high, especially in the patients aged <20 years and those with a longer duration of symptoms before diagnosis. Therefore, it is necessary to screen for HBV serologic markers and generate a detailed vaccination plan for patients newly diagnosed with IBD
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