Neuroprotective effects of CysLT2R antagonist on Angiostrongylus cantonensis-induced edema and meningoencephalitis.

Cysteinyl leukotrienes (CysLTs) can induce a disruption of the blood-brain barrier (BBB), and this reaction is mediated by cysteinyl-leukotriene receptors. In this study, we used A. cantonensis-induced eosinophilic meningoencephalitis as a model to investigate whether the CysLT2 receptor involved in the pathogenesis of angiostrongyliasis meningoencephalitis. The present study provides evidence that the CysLT2 receptor antagonist HAMI3379 reduced the number of infiltrated eosinophils and brain edema in eosinophilic meningoencephalitis. Additionally, we found that HAMI3379 significantly decreased the protein levels of M1 polarisation markers (CD80, iNOS, IL-5 and TNF-α), increased the expression of M2 polarisation markers (CD206, IL-10 and TGF-ß) both in vivo and in vitro. Matrix metalloproteinase-9, S100B, GFAP, fibronectin, and claudin-5 were markedly lower after HAMI3379 treatment. Therefore, HAMI3379 reduced the BBB dysfunction in angiostrongyliasis meningoencephalitis. We have identified microRNA-155 as a BBB dysfunction marker in eosinophilic meningoencephalitis. The results showed that microRNA-155 was 15-fold upregulated in eosinophilic meningoencephalitis and 20-fold upregulated after HAMI3379 treatment. Our results suggest that CysLT2R may be involved in A. cantonensis-induced brain edema and eosinophilic meningoencephalitis and that down-regulation of CysLT2R could be a novel and potential therapeutic strategy for the treatment of angiostrongyliasis meningoencephalitis.

Heme oxygenase-1 modulates brain inflammation and apoptosis in mice with angiostrongyliasis.

The rat nematode lungworm Angiostrongylus cantonensis undergoes obligatory intracerebral migration in its hosts and causes eosinophilic meningitis or meningoencephalitis. Heme oxygenase 1 (HO-1) has several cytoprotective properties such as anti-oxidative, anti-inflammatory, and anti-apoptotic effects. HO-1 in brain tissues was induced in A. cantonensis-infected group and showed positive modulation in cobalt protoporphyrin (CoPP)-treated groups. Assay methods for the therapeutic effect include western blot analysis, enzyme-linked immunosorbent assay, gelatin zymography, blood-brain barrier permeability evaluation and eosinophil count in cerebrospinal fluid. The combination of albendazole (ABZ) and CoPP significantly decreased pro-inflammatory cytokines, tumor necrosis factor-α, interleukin (IL)-1ß, IL-5, and IL-33 but significantly increased anti-inflammatory cytokines IL-10 and transforming growth factor-ß. In addition, worm recovery, matrix metalloproteinase-9, BBB permeability, and eosinophil counts were decreased in the ABZ and CoPP co-treated groups. Induction of HO-1 with CoPP strongly inhibited the protein levels of caspase-3 and increased the induction of annexin-V and B-cell leukemia 2. Thus, co-treatment with ABZ and CoPP prevented A. cantonensis-induced eosinophilic meningoencephalitis and its anti-apoptotic effect by promoting HO-1 signaling prior to BBB dysfunction. HO-1 induction might be a therapeutic modality for eosinophilic meningoencephalitis.

Hepatitis C virus E2 protein involve in insulin resistance through an impairment of Akt/PKB and GSK3ß signaling in hepatocytes.

BACKGROUND: Hepatitis C virus (HCV) infection may cause liver diseases of various severities ranging from primary acute infection to life-threatening diseases, such as cirrhosis or hepatocellular carcinoma with poor prognosis. According to clinical findings, HCV infection may also lead to some extra-hepatic symptoms, including type 2 diabetes mellitus (DM). Since insulin resistance is the major etiology for type 2 DM and numerous evidences showed that HCV infection associated with insulin resistance, the involvement of E2 in the pathogenesis of type 2 DM and underlying mechanisms were investigated in this study. METHODS: Reverse transcription and real-time PCR, Western blot assay, Immunoprecipitation, Glucose uptake assay and analysis of cellular glycogen content. RESULTS: Results showed that E2 influenced on protein levels of insulin receptor substrate-1 (IRS-1) and impaired insulin-induced Ser308 phosphorylation of Akt/PKB and Ser9 phosphorylation of GSK3ß in Huh7 cells, leading to an inhibition of glucose uptake and glycogen synthesis, respectively, and eventually insulin resistance. CONCLUSIONS: Therefore, HCV E2 protein indeed involved in the pathogenesis of type 2 DM by inducing insulin resistance.

Simvastatin inhibits glucose-stimulated vascular smooth muscle cell migration involving increased expression of RhoB and a block of Ras/Akt signal.

BACKGROUND: Diabetic patients are at high risk to develop atherosclerotic cardiovascular disease and have a higher restenotic rate after percutaneous coronary intervention (PCI). Statins improve cardiovascular outcome and reduce restenosis after PCI by inhibiting proliferation and migration of vascular smooth muscle cells (VSMCs). But the effect of statins on diabetes without dyslipidemia was still not fully understood. Our previous study has demonstrated that simvastatin inhibits VSMC proliferation in high glucose status without dyslipidemia, inducing a G0/G1 phase cell cycle growth arrest by acting on multiple steps upstream of pRb, including inhibition of CDK2/4 expression and upregulation of p53, p21, p16, and p27. METHOD: Following our previous study, we investigated the mechanism of simvastatin inhibition of VSMC migration in a diabetes-like model (A7r5 cells under high glucose conditions without dyslipidemia). RESULTS: Under high glucose conditions, simvastatin dose-dependently inhibited VSMC migration, decreased PI3K/Akt pathway activity, reduced c-Raf and Ras expression, increased RhoB but not RhoA, Rac1, and Cdc2 expression, dose-dependently inhibited MMP-2, but not MMP-9, activity, and dose-dependently inhibited NF-κB activity. CONCLUSION: The inhibition of VSMC migration under high glucose conditions was via two different pathways. The first pathway is mevalonate-related but not RhoA protein-related and involves suppression of Ras and PI3K/Akt signals. The second pathway is not mevalonate-related and involves increasing RhoB expression directly.

Anti-inflammatory effects of Cynanchum taiwanianum rhizome aqueous extract in IL-1ß-induced NRK-52E cells.

CONTEXT: Cynanchum taiwanianum T. Yamaza (Asclepiadaceae) is a medicinal herb used in folk medicine for the treatment of several inflammation-related diseases such as hepatitis and dermatitis in Taiwan. OBJECTIVE: In the present study, we investigated the anti-inflammatory effect of C. taiwanianum T. Yamaza rhizome aqueous extract (CTAE). MATERIALS AND METHODS: The present study investigated the anti-inflammatory effect of CTAE using IL-1ß-induced NRK-52E cells. Production of NO and PGE(2) by ELISA, the mRNA and protein expression of iNOS and COX-2, phosphorylation of IκBα, and activation of NF-κB by RT-PCR and western blotting were determined. RESULTS: The CTAE significantly (P < 0.05) inhibited NO and PGE(2) production (decreased by 46.1% and 51%, respectively), and also significantly (P < 0.05) attenuated protein and mRNA expression of iNOS and COX-2 (decreased by 90% and 55% for iNOS and by 72% and 74%% for COX-2, respectively) in IL-1ß-induced NRK-52E cells, in a dose-dependent manner, without obvious cytotoxic effects. Furthermore, the CTAE suppressed the NF-κB nuclear translocation, in terms of inhibition of IκBα phosphorylation. DISCUSSION AND CONCLUSION: Our results provided evidence for its folkloric uses and suggest that the anti-inflammatory activities of CTAE may result from the inhibition of inflammatory mediators, such as NO and PGE(2), and an upstream suppression of a NF-κB-dependent mechanism, might be involved.

Solanum nigrum L. polyphenolic extract inhibits hepatocarcinoma cell growth by inducing G2/M phase arrest and apoptosis.

BACKGROUND: Hepatocellular carcinoma (HCC) is a rapidly progressive cancer with poor prognosis. However, there have been no significant new developments in treating liver cancer. To search for an effective agent against HCC progression, we prepared a polyphenolic extract of Solanum nigrum L. (SNPE), a herbal plant indigenous to Southeast Asia and commonly used in oriental medicine, to evaluate its inhibitive effect on hepatocarcinoma cell growth. The growth inhibition of HepG2 cells in vitro and in vivo was determined in the presence of SNPE. RESULTS: We found 1 µg mL(-1) SNPE-fed mice showed decreased tumor weight and tumor volume by 90%. Notably, 2 µg mL(-1) SNPE resulted in almost complete inhibition of tumor weight as well as tumor volume. In line with this notion, SNPE reduced the viability of HepG(2) cells in a dose-dependent manner. HepG(2) cells were arrested in the G(2)/M phase of the cell cycle; meanwhile, the protein levels of cell CDC25A, CDC25B, and CDC25C were clearly reduced. Moreover, sub-G(1) phase accumulation and caspases-3, 8, and 9 cleavages were induced by SNPE. CONCLUSION: This study shows that SNPE is a potent agent for HCC treatment through targeting G(2)/M arrest and apoptosis induction, achieving cell growth inhibition.

Polyphenol-rich extract from mulberry leaf inhibits vascular smooth muscle cell proliferation involving upregulation of p53 and inhibition of cyclin-dependent kinase.

This study was carried out to investigate the impact of polyphenol-rich extract from mulberry leaf on the proliferation of vascular smooth muscle cell (VSMC) and verify its mechanism in vitro. VSMC proliferation is an important pathophysiological process in the development of atherosclerosis, which is the major cause of coronary artery disease (CAD). Polyphenol-rich foods, such as mulberry leaf, have been reported to reduce the risk of CAD. The effect of mulberry leaf extract (MLE) on cell growth was measured by a growth curve assay, on distribution of cells in the cell cycle by flow cytometry, and on cyclin-dependent kinase (CDK) activity and cell-cycle regulatory proteins by Western blot, immunoblotting, and immunoprecipitation analyses. The results showed that MLE induced phosphorylation of p53, promoted expression of p21 and p27, decreased CDK2/4 activity, inhibited phosphorylation of Rb, and thereby blocked the G1 to S transition in the cell cycle.

Angiostrongylus cantonensis: induction of urokinase-type PA and degradation of type IV collagen in rat lung granulomatous fibrosis.

Granuloma formation and subsequent fibrosis around Angiostrongylus cantonensis larvae in the lungs were induced experimentally in Sprague-Dawley strain rats. Casein zymogram analysis demonstrated that urokinase-type plasminogen activator (uPA) activity was increased during lung inflammation and fibrosis. Granulomatous fibrosis, type IV collagen degradation and activation of uPA occur simultaneously. Furthermore, the present study demonstrated that collagen avidly binds uPA. Immunohistochemical observations showed localization of uPA within the infiltrating leucocytes. We propose that uPA may participate in A. cantonensis-induced granulomatous fibrosis.