Isosteviol Protects H9c2 Cells Against Hypoxia-reoxygenation by Activating ERK1/2.

AIMS: In the present study, we have investigated the cardioprotective properties of Isosteviol (STV) under conditions of hypoxia-reoxygenation and elucidated the underlying mechanism. BACKGROUND: In our previous studies, we have determined that STV exhibits neuro- and cardio-protective properties. However, the mechanism underlying STV-induced cardioprotection has not yet been fully understood. METHODS: All experiments were performed on rat heart embryonic H9c2 cell line. To induce hypoxia- reoxygenation, cells were exposed to 1% oxygen (in no glucose and no sodium pyruvate DMEM) following by reoxygenation (using fully supplemented MEM). Cells viability was tested by MTT assay, and protein levels were compared by Western blotting. RESULTS: Treatment of heart embryonic H9c2 cells with STV (10 µM) significantly increased the survival of cells exposed to hypoxia-reoxygenation. STV (10 µM) activated ERK1/2 and DRP1 in hypoxia-reoxygenation, but did not have any effects on ERK1/2 or DRP1 in normoxia. STV (10 µM) did not regulate CAMKII, AKT or AMPK signaling pathways. CONCLUSION: Taken all together, our findings demonstrate that 1) STV protects H9c2 cells against hypoxia-reoxygenation and that 2) this effect is mediated via ERK1/2. The property of STV that selectively activates ERK1/2 in cells exposed to stress, but not in cells under non-stress conditions, makes this compound a promising candidate-drug for therapy against myocardial ischemia-reperfusion in clinical practice.

A locus on mouse chromosome 13 inversely regulates CD1d expression and the development of invariant natural killer T-cells.

Invariant natural killer T (iNKT)-cell development is controlled by many polymorphic genes present in commonly used mouse inbred strains. Development of type 1 diabetes (T1D) in NOD mice partly results from their production of fewer iNKT-cells compared with non-autoimmune-prone control strains, including ICR. We previously identified several iNKT-cell quantitative trait genetic loci co-localized with known mouse and human T1D regions in a (NOD × ICR)F2 cross. To further dissect the mechanisms underlying the impaired iNKT-cell compartment in NOD mice, we carried out a series of bone marrow transplantation as well as additional genetic mapping studies. We found that impaired iNKT-cell development in NOD mice was mainly due to the inability of their double-positive (DP) thymocytes to efficiently select this T-cell population. Interestingly, we observed higher levels of CD1d expression by NOD than by ICR DP thymocytes. The genetic control of the inverse relationship between the CD1d expression level on DP thymocytes and the frequency of thymic iNKT-cells was further mapped to a region on chromosome 13 between 60.12 and 70.59 Mb. The NOD allele was found to promote CD1d expression and suppress iNKT-cell development. Our results indicate that genetically controlled physiological variation of CD1d expression levels modulates iNKT-cell development.

Genetic control of murine invariant natural killer T cells maps to multiple type 1 diabetes regions.

Reduced frequency of invariant natural killer T (iNKT) cells has been indicated as a contributing factor to type 1 diabetes (T1D) development in NOD mice. To further understand the genetic basis of the defect, we generated (NOD × ICR)F2 mice to map genes that control iNKT-cell development. We determined frequencies of thymic and splenic iNKT cells, as well as the ratio of CD4-positive and -negative subsets in the spleens of 209 F2 males. Quantitative trait loci (QTL) analysis revealed five loci that exceed the significant threshold for the frequency of thymic and/or splenic iNKT cells on Chromosomes (Chr) 1, 5, 6, 12 and 17. Three significant loci on Chr 1, 4 and 5 were found for the ratio of CD4-positive and -negative splenic iNKT cells. Comparisons with previously known mouse T1D susceptibility (Idd) loci revealed two significant QTL peak locations, respectively, mapped to Idd regions on Chr 4 and 6. The peak marker location of the significant Chr 12 iNKT QTL maps to within 0.5 Mb of a syntenic human T1D locus. Collectively, our results reveal several novel loci controlling iNKT-cell development and provide additional information for future T1D genetic studies.

Adjuvant therapy for atrial fibrillation.

Atrial fibrillation (AF) is the most common heart rhythm disorder, with increasing prevalence in the aging US population and affecting more than 2.3 million people. Current approaches for managing AF are rate- or rhythm-control strategies, both using anti-thrombotic therapy to prevent thromboembolism. While great advances have been made in understanding the pathophysiology of AF, few new strategies have shown promise in prevention or treatment of AF. Recent data suggest that non-antiarrhythmic medication may be useful in modifying the substrate that allows AF precipitation and perpetuation. This article reviews the data on the role of these agents in the prevention and management of AF as an adjunct to standard therapy.

Incredibly late thromboses in first generation drug eluting stents: a case series.

BACKGROUND: The drug-eluting stents have decreased the incidence of instent restenosis compared to bare metal stents. But, the incidence of late and very late stent thrombosis has increased with the drug-eluting stents. CASE PRESENTATION: We are here, reporting three cases of incredibly late instent thrombosis, each one occurring after more than 50 months of drug-eluting stent placement. CONCLUSION: The occurrence of stent thrombosis as late as 5 years has been reported in literature. This highlights the importance that there may be no limit to the time duration to the occurrence of very late stent thrombosis and dual antiplatelet therapy with aspirin and clopidogrel may have to be continued indefinitely in patients with drug-eluting stents.

Antimicrobial activities of Eugenol and Cinnamaldehyde against the human gastric pathogen Helicobacter pylori.

BACKGROUND: Eradication of Helicobacter pylori is an important objective in overcoming gastric diseases. Many regimens are currently available but none of them could achieve 100% success in eradication. Eugenol and cinnamaldehyde that are commonly used in various food preparations are known to possess antimicrobial activity against a wide spectrum of bacteria. AIM: The present study was performed to assess the in vitro effects of eugenol and cinnamaldehyde against indigenous and standard H. pylori strains, their minimum inhibitory concentrations (MICs) and time course lethal effects at various pH. METHODS: A total of 31 strains (29 indigenous and one standard strain of H. pylori ATCC 26695, one strain of E. coli NCIM 2089) were screened. Agar dilution method was used for the determination of drug sensitivity patterns of isolates to the commonly used antibiotics and broth dilution method for the test compounds. RESULTS: Eugenol and cinnamaldehyde inhibited the growth of all the 30 H. pylori strains tested, at a concentration of 2 mug/ml, in the 9th and 12th hours of incubation respectively. At acidic pH, increased activity was observed for both the compounds. Furthermore, the organism did not develop any resistance towards these compounds even after 10 passages grown at sub-inhibitory concentrations. CONCLUSION: These results indicate that the two bioactive compounds we tested may prevent H. pylori growth in vitro, without acquiring any resistance.

Polymerase chain reaction based analysis of the cytotoxin associated gene pathogenicity island of Helicobacter pylori from saliva: an approach for rapid molecular genotyping in relation to disease status.

BACKGROUND AND AIMS: The genetic composition of the intricate cytotoxin associated gene pathogenicity island (cag PAI) of Helicobacter pylori is known to significantly influence the outcome of the disease. Hence, analysis of complete cag PAI of H. pylori isolated from saliva would be of immense importance in standardizing saliva as a reliable non-invasive diagnostic specimen and also to evaluate the type of H. pylori infection. The aim of the present study was to analyze the genes of cag PAI of H. pylori for their presence and correlating them with the disease status of the patients. METHODS: One hundred and twenty patients (55 duodenal ulcer [DU], 25 gastric ulcer and 40 non-ulcer dyspepsia [NUD]) were investigated for the present study. Eight pairs of oligonucleotide primers (cagA1, cagA2, cagAP1, cagAP2, cagE, cagT, LEC1 and LEC2) of five different loci; cagA, cagA promoter region, cagE which represents cagI region, cagT and LEC representing cagII were used to detect the presence of the cag PAI genes by polymerase chain reaction. RESULTS: The comprehensive analysis of the genes constituting cag PAI showed almost equivalent prevalence of all the genes between both the study groups (ulcer and NUD) included. Little significant difference was found in the percentage distribution in both the clinical groups. cagE and cagT were found in a larger proportion of the ulcer group (92.5% and 96.2%) compared with the NUD group (77.5% and 85%), respectively. CONCLUSION: Saliva could be efficiently used as a non-invasive source for H. pylori and cagT might be an important locus of the cag PAI, thus greatly influencing the disease condition of the subjects.