Oroxylin A induces dissociation of hexokinase II from the mitochondria and inhibits glycolysis by SIRT3-mediated deacetylation of cyclophilin D in breast carcinoma

Oroxylin A is a major active component of the Chinese traditional medicinal plant Scutellaria baicalensis Georgi, which has been reported as a potential anticancer drug. We demonstrated that, Oroxylin A inhibited the glycolysis and the binding of hexokinase II (HK II) with mitochondria in human breast carcinoma cell lines, which was dependent on sirtuin-3 (SIRT3). The level of SIRT3 in mitochondria was increased by Oroxylin A. Then SIRT3 deacetylated cyclophilin D, diminished its peptidyl-prolyl cis-trans isomerase activity and induced its dissociation from the adenine nucleotide translocator. Finally, SIRT3-induced inactivation of cyclophilin D resulted in the detachment of mitochondrial HK II and the inhibition of glycolysis. These results have important implications for the metabolism reprogramming effect and the susceptibility to Oroxylin A-induced mitochondrial cytotoxicity through the regulation of SIRT3 in breast carcinoma.

Citalopram enhances neurovascular regeneration and sensorimotor functional recovery after ischemic stroke in mice

Recent clinical trials have demonstrated that treatment with selective serotonin reuptake inhibitors after stroke enhances motor functional recovery; however, the underlying mechanisms remain to be further elucidated. We hypothesized that daily administration of the clinical drug citalopram would produce these functional benefits via enhancing neurovascular repair in the ischemic peri-infarct region. To test this hypothesis, focal ischemic stroke was induced in male C57/B6 mice by permanent ligation of distal branches of the middle cerebral artery to the barrel cortex and 7-min occlusion of the bilateral common carotid arteries. Citalopram (10mg/kg, i.p.) was injected 24h after stroke and daily thereafter. To label proliferating cells, bromo-deoxyuridine was injected daily beginning 3 days after stroke. Immunohistochemical and functional assays were performed to elucidate citalopram-mediated cellular and sensorimotor changes after stroke. Citalopram treatment had no significant effect on infarct formation or edema 3 days after stroke; however, citalopram-treated mice had better functional recovery than saline-treated controls 3 and 14 days after stroke in the adhesive removal test. Increased expression of brain-derived neurotrophic factor was detected in the peri-infarct region 7 days after stroke in citalopram-treated animals. The number of proliferating neural progenitor cells and the distance of neuroblast migration from the sub-ventricular zone toward the ischemic cortex were significantly greater in citalopram-treated mice at 7 days after stroke. Immunohistochemical staining and co-localization analysis showed that citalopram-treated animals generated more new neurons and microvessels in the peri-infarct region 21 and 28 days after stroke. Taken together, these results suggest that citalopram promotes post-stroke sensorimotor recovery likely via enhancing neurogenesis, neural cell migration and the microvessel support in the peri-infarct region of the ischemic brain.

The regulatory role of NF-κB in autophagy-like cell death after focal cerebral ischemia in mice

Autophagy may contribute to ischemia-induced cell death in the brain, but the regulation of autophagic cell death is largely unknown. Nuclear factor kappa B (NF-κB) is a regulator of apoptosis in cerebral ischemia. We examined the hypothesis that autophagy-like cell death could contribute to ischemia-induced brain damage and the process was regulated by NF-κB. In adult wild-type (WT) and NF-κB p50 knockout (p50(-/-)) mice, focal ischemia in the barrel cortex was induced by ligation of distal branches of the middle cerebral artery. Twelve to 24h later, autophagic activity increased as indicated by enhanced expression of Beclin-1 and LC3 in the ischemic core and/or penumbra regions. This increased autophagy contributed to cell injury, evidenced by terminal deoxynucleotidyltransferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) co-staining and a protective effect achieved by the autophagy inhibitor 3-methyladenine. The number of Beclin-1/TUNEL-positive cells was significantly more in p50(-/-) mice than in WT mice. Neuronal and vascular cell death, as determined by TUNEL-positive cells co-staining with NeuN or Collagen IV, was more abundant in p50(-/-) mice. Immunostaining of the endothelial cell tight junction marker occludin revealed more damage to the blood-brain barrier in p50(-/-) mice. Western blotting of the peri-infarct tissue showed a reduction of Akt-the mammalian target of rapamycin (mTOR) signaling in p50(-/-) mice after ischemia. These findings provide the first evidence that cerebral ischemia induced autophagy-like injury is regulated by the NF-κB pathway, which may suggest potential treatments for ischemic stroke.

Association of suppressor of cytokine signalling 3 polymorphisms with insulin resistance in patients with chronic hepatitis C

Suppressor of cytokine signalling 3 is thought to be associated with insulin resistance in patients with chronic hepatitis C. We evaluated the role of suppressor of cytokine signalling 3 polymorphisms in determining insulin resistance in patients with chronic hepatitis C. Two hundred and ninety untreated hepatitis C virus-infected patients without diabetes and cirrhosis were genotyped for the SNPs rs4969168, rs4969170 and rs12952093 of suppressor of cytokine signalling 3 using the TaqMan Genotyping Assay. We found that the rs4969170 AA genotype and rs4969170 A allele frequency were significantly more common in the insulin-resistant group than the non-insulin-resistant group (89.5% vs 76.1%, OR = 2.693, 95% CI: 1.221-5.939, P = 0.012 and 94.8% vs 88.0%, OR = 2.463, 95% CI: 1.151-5.271, P = 0.017, respectively). Haplotype G-C was likely associated with non-insulin resistance (adjusted P = 0.011). Multiple logistic regression analysis indicates that the independent risk factors for insulin resistance are the SNP rs4969170 AA genotype (OR = 3.005, 95% CI: 1.194-7.560, P = 0.019), HCV genotype 1 (OR = 2.524, 95% CI: 1.099-5.794, P = 0.029) and BMI (OR = 0.514, 95% CI: 0.265-0.999, P = 0.05).

Aldo-keto reductase 1C3 may be a new radioresistance marker in non-small-cell lung cancer

Human aldo-keto reductase 1C3, type 2 3α-hydroxysteroid dehydrogenase (HSD)/type 5 17β-HSD (AKR1C3) is known to be involved in steroid, prostaglandin and lipid aldehyde metabolism. The role of AKR1C3 in the radiosensitivity to X-rays of human non-small-cell lung cancer (NSCLC) cells was explored. In this study, a specific small interfering RNA (siRNA) to target the AKR1C3 gene was used. A suite of readouts including cell survival were determined using a colony formation assay; apoptosis evaluated by Annexin V expression levels, irradiation-induced cytotoxicity established using a MTT cell viability assay and cell cycle distribution measured by flow cytometry were used in characterizing the role of the AKR1C3 gene. Although AKR1C3 was significantly overexpressed in both our radioresistant subclone cells and NSCLC tissues, a specific AKR1C3 siRNA significantly enhanced cell radiosensitivity and was concomitant with decreased expression of this gene. Furthermore, reduced interleukin-6 (IL-6)-mediated radioresistance was observed when siRNA was used to knock down AKR1C3 activity. This AKR1C3-mediated radioresistance was correlated with an arrest in the G2/M cell cycle and a decreased induction of apoptosis. AKR1C3 may present a potential therapeutic target in addressing radioresistance of NSCLC, and in particular in IL-6-mediated radioresistance.

Severity of portal hypertension and prediction of postoperative liver failure after liver resection in patients with Child–Pugh grade A cirrhosis

Background

Patients with Child–Pugh grade A cirrhosis and clinical evidence of portal hypertension are likely to develop posthepatectomy liver failure (PHLF). Whether such patients are suitable candidates for partial hepatectomy is controversial. This study explored the impact of portal venous pressure (PVP) on PHLF and the possibility of stratifying patients with Child–Pugh grade A cirrhosis for risk of PHLF using clinical data alone.

Methods

Between April 2009 and May 2011, consecutive patients who underwent partial hepatectomy for hepatocellular carcinoma and intraoperative measurement of PVP were included in this prospective study. Using signs of clinically significant portal hypertension (CSPH), patients with Child–Pugh grade A cirrhosis were subclassified into three groups: no, mild and severe CSPH. Risk factors for PHLF were subjected to univariable and multivariable analysis, and receiver operating characteristic (ROC) curve analysis.

Results

Sixty-seven (35·3 per cent) of 190 patients developed PHLF, which was persistent in 12 patients (6·3 per cent). Four patients (2·1 per cent) died from PHLF within 3 months of surgery. Multivariable analysis showed both PVP and CSPH to be independent predictors of PHLF (P < 0·001). PVP values, incidence of PHLF and persistent PHLF were significantly higher in the severe CSPH group than in the other two groups (P < 0·001). Severe CSPH (odds ratio 27·68, P = 0·005) and a preoperative neutrophil : lymphocyte ratio (NLR) of 2·8 or above (odds ratio 49·75, P = 0·002) were independent factors affecting the incidence of persistent PHLF.

Conclusion

The severity of CSPH, corresponding to different PVP levels, could be used to stratify patients with Child-Pugh grade A cirrhosis and to predict the incidence of PHLF. Patients with severe CSPH or a NLR of 2·8 or above were more likely to develop persistent PHLF after partial hepatectomy.

Prevalence of periodontitis in adults in the United States: 2009 and 2010

This study estimated the prevalence, severity, and extent of periodontitis in the adult U.S. population, with data from the 2009 and 2010 National Health and Nutrition Examination Survey (NHANES) cycle. Estimates were derived from a sample of 3,742 adults aged 30 years and older, of the civilian non-institutionalized population, having 1 or more natural teeth. Attachment loss (AL) and probing depth (PD) were measured at 6 sites per tooth on all teeth (except the third molars). Over 47% of the sample, representing 64.7 million adults, had periodontitis, distributed as 8.7%, 30.0%, and 8.5% with mild, moderate, and severe periodontitis, respectively. For adults aged 65 years and older, 64% had either moderate or severe periodontitis. Eighty-six and 40.9% had 1 or more teeth with AL ≥ 3 mm and PD ≥ 4 mm, respectively. With respect to extent of disease, 56% and 18% of the adult population had 5% or more periodontal sites with ≥ 3 mm AL and ≥ 4 mm PD, respectively. Periodontitis was highest in men, Mexican Americans, adults with less than a high school education, adults below 100% Federal Poverty Levels (FPL), and current smokers. This survey has provided direct evidence for a high burden of periodontitis in the adult U.S. population.

Sci-Fri AM: Imaging - 09: Serial estimation of cross-talk for correction in dual-isotope imaging with dynamic tracers

The recent radioisotope shortage has led to interest in non-Tc99m-based tracers. We have developed a novel I-123-labelled myocardial perfusion imaging tracer. We compare the I123-tracer to the clinical standard of Tc99m tetrofosmin in vivo in a rat model using a small-animal SPECT/CT camera. SPECT distinguishes different isotopes based on the different energies of the emitted gamma rays and thus allows simultaneous comparison of two tracer distributions in the same animal. Dual-isotope imaging is complicated by cross-talk between the energy windows of the isotopes. Standard energy-window-based correction methods are difficult to employ because of the proximity in energy of Tc99m (140keV) and I123 (159keV). Imaging the second tracer's energy window prior to its injection provides an estimate of the cross-talk. However, this estimate is only accurate if the tracer distribution is static. We use serial imaging prior to the introduction of the second tracer to estimate the dynamics of the first tracer and interpolate the cross-talk images to provide a more accurate correction. We used rat models of myocardial disease (n=3). I123 tracer was injected and imaged for one hour at 20min intervals. The Tc99m tetrofosmin was then injected and 30min later, a dual-isotope image was obtained. The impact of this approach is assessed by comparing the differences in the Tc99m-tetrofosmin image using this method with correction by simple correction for physical decay. The interpolative approach improves the accuracy of the correction by 2%-5% and thereby enhances the comparison of the two tracers.

Effectiveness of statins in chronic kidney disease

BACKGROUND

Previous studies show that statins reduce total cholesterol (TC) concentration by both 21% in primary prevention (PP) and secondary prevention (SP) in clinical trials and by ∼24% in the general population. There are few data about the efficacy of statins on TC concentration and cardiovascular (CV) outcome in patients with chronic kidney disease (CKD). We evaluated the reduction of TC concentration and subsequent risk of CV morbidity and mortality with statins in CKD patients.

METHODS

A population-based cohort study using a record-linkage database in Tayside, Scotland. A total of 2369 patients who had a primary diagnosis of CKD from Scottish Morbidity Record data or biochemistry database (serum creatinine of 220 μmol/l or higher) and who had at least two separate TC measurements between 1993 and 2007 were studied. Patients were categorized into statin-exposed and statin-unexposed groups according to statin use status during the follow-up. They were also classified into PP (n = 1325) and SP (n = 1044) cohorts at the entry date. The main outcomes were TC concentration change from baseline, CV events [Antiplatelet Trialist's Collaboration (APTC)] and all-cause mortality during the follow-up. Cox regression models, in which statin use was a time-dependent variable, were employed to assess the risk of outcome and adjusted for other known confounders.

RESULTS

Statin-associated TC concentrations decreased by 0.59 mmol/l (12%) in PP cohort and 0.56 mmol/l (13%) in SP cohort from 4.77 and 4.48 mmol/l at baselines, respectively. Statin use was associated with a reduced risk of APTC events, CV mortality or all-cause mortality in PP {adjusted hazard ratio (HR), 0.65 [95% confidence interval (CI) 0.48-0.88]; 0.73 (95% CI 0.52-0.98); 0.59 (95% CI 0.48-0.73)} and SP [adjusted HR, 0.66 (95% CI 0.52-0.84); 0.60 (95% CI 0.47-0.77); 0.56 (95% CI 0.47-0.68)], respectively.

CONCLUSION

Statin use reduced TC concentrations by ∼13% in patients with CKD. Statins were protective of APTC events, CV mortality and all-cause mortality in patients with or without established CV disease.

Differential expression of microRNAs during allograft rejection

MicrorRNA are small noncoding RNA molecules that regulate the posttranscriptional expression of target genes. In addition to being involved in many biologic processes, microRNAs are important regulators in innate and adaptive immune responses. Distinct sets of expressed microRNAs are found in different cell types and tissues and aberrant expression of microRNAs is associated with many disease states. MicroRNA expression was examined in a model of heterotopic heart transplantation by microarray analyses and a unique profile was detected in rejecting allogeneic transplants (BALB/c → C57BL/6) as compared to syngeneic transplants (C57BL/6 → C57BL/6). The microRNA miR-182 was significantly increased in rejecting cardiac allografts and in mononuclear cells that infiltrate the grafts. Forkhead box (FOX) proteins are a family of important transcription factors and FOXO1 is a target of miR-182. As miR-182 increases after transplant, there is a concomitant posttranscriptional decrease in FOXO1 expression in heart allografts that is localized to both the cardiomyocytes and CD3(+) T cells. The microRNA miR-182 is significantly increased in both peripheral blood mononuclear cells and plasma during graft rejection suggesting potential as a biomarker of graft status. Our results identify microRNAs that may regulate alloimmune responses and graft outcomes.

IL28B genetic variants and gender are associated with spontaneous clearance of hepatitis C virus infection

Single nucleotide polymorphisms (SNPs) near the IL28B gene have been shown to be associated with response to treatment for chronic hepatitis C and also with spontaneous clearance of hepatitis C virus (HCV) infection. We analysed the association between IL28B genetic variants and spontaneous clearance of HCV infection in 376 HCV-infected Chinese paid plasma donors. Genotyping of eight SNPs near the IL28B region was performed by the iPLEX system (MassARRAY(®) SNP Genotyping; Sequenom) in all donors, and sequencing was performed on all 80 donors who cleared HCV and on 160 of 296 donors who did not clear HCV to validate the genotypes. Eighty (21.3%) donors spontaneously cleared HCV. Four SNPs were significantly associated with spontaneous HCV clearance: rs8099917 TT (vs GT), rs8105790 TT (vs CT), rs12980275 AA (vs AG) and rs10853728 CC (vs CG or GG) with OR (95% CI) 15.27 (2.07-112.50), 14.88 (2.02-109.72), 7.92 (1.88-33.32) and 2.32 (1.22-4.42) respectively. No association between the other four IL28B SNPs including rs12979860 and spontaneous HCV clearance was found. Women had a higher rate of spontaneous HCV clearance than men [56/213 (26.3%) vs 24/163 (14.6%), P = 0.007], and this was true even after stratification for IL28B genotypes with OR of 1.9-2.2 among those with favourable genotypes. Our results confirmed that IL28B polymorphism is associated with spontaneous clearance of HCV in Chinese subjects, but the SNPs that predict HCV clearance in Chinese subjects were different from those reported in Caucasians. Women were more likely to clear HCV infection regardless of IL28B genotypes.

Characterization of nine novel microsatellite loci for the Venus clam (Cyclina sinensis)

The Venus clam, Cyclina sinensis, is one of the most important bivalves in China marine aquaculture. Using (CA)(15)-enriched genomic libraries of this species, nine novel polymorphic microsatellite loci were isolated and characterized. The mean number of observed alleles per locus was 16 (range 8-24). The observed and expected heterozygosity ranged from 0.119 to 0.872 and from 0.626 to 0.931, respectively. Three loci had significant departure from Hardy-Weinberg equilibrium and non-significant linkage disequilibrium was found among all nine loci. These highly informative microsatellite markers should be useful for population genetic analyses of C. sinensis.