The Apoptotic Effects of Toosendanin Are Partially Mediated by Activation of Deoxycytidine Kinase in HL-60 Cells

Triterpenoid toosendanin (TSN) exhibits potent cytotoxic activity through inducing apoptosis in a variety of cancer cell lines. However, the target and mechanism of the apoptotic effects by TSN remain unknown. In this study, we captured a specific binding protein of TSN in HL-60 cells by serial affinity chromatography and further identified it as deoxycytidine kinase (dCK). Combination of direct activation of dCK and inhibition of TSN-induced apoptosis by a dCK inhibitor confirmed that dCK is a target for TSN partially responsible for the apoptosis in HL-60 cells. Moreover, the activation of dCK by TSN was a result of conformational change, rather than auto-phosphorylation. Our results further imply that, in addition to the dATP increase by dCK activation in tumor cells, dCK may also involve in the apoptotic regulation.     

Clinical Significance and Role of Lymphatic Vessel Invasion as a Major Prognostic Implication in Non-Small Cell Lung Cancer: A Meta-Analysis

Background

Lymphatic vessel invasion (LVI) exerts an important process in the progression and local spread of cancer cells. However, LVI as a prognostic factor for survival in non-small cell lung cancer (NSCLC) remains controversial.

Methodology/Principal Findings

A meta-analysis of published studies from PubMed and EMBASE electronic databases was performed to quantity the effects of LVI on both relapse-free survival and overall survival for patients with NSCLC. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to assess the strength of these effects. This meta-analysis included 18,442 NSCLC patients from 53 eligible studies. LVI appeared in 32.1% (median; range, 2.8% to 70.9%) of tumor samples. In all, patients with LVI were 2.48 times more likely to relapse by univariate analysis (95% CI: 1.92–3.22) and 1.73 times by multivariate analysis (95% CI: 1.24–2.41) compared with those without LVI. For the analyses of LVI and overall survival, the pooled HR estimate was 1.97 (95% CI: 1.75–2.21) by univariate analysis and 1.59 (95% CI: 1.41–1.79) by multivariate analysis. Multivariate analysis showed a risk was 91% higher for recurrence (HR  = 1.91, 95% CI: 1.14–2.91) and 70% higher for mortality (HR = 1.70, 95% CI: 1.38–2.10) in LVI-positive I stage patients compared with LVI-negative I stage patients. Subgroup analyses showed similar significant adjusted risks for recurrence and death in adenocarcinomas, and a significant adjusted risk for death in studies that utilized elastic staining with or without immunohistochemistry in defining LVI.

Conclusions/Significance

The present study indicates that LVI appears to be an independent poor prognosticator in surgically managed NSCLC. NSCLC patients with LVI would require a more aggressive treatment strategy after surgery. However, large, well-designed prospective studies with clinically relevant modeling and standard methodology to assess LVI are required to address some of these important issues.     

Small-RNA Deep Sequencing Reveals Arctium tomentosum as a Natural Host of Alstroemeria virus X and a New Putative Emaravirus

Background

Arctium species (Asteraceae) are distributed worldwide and are used as food and rich sources of secondary metabolites for the pharmaceutical industry, e.g., against avian influenza virus. RNA silencing is an antiviral defense mechanism that detects and destroys virus-derived double-stranded RNA, resulting in accumulation of virus-derived small RNAs (21–24 nucleotides) that can be used for generic detection of viruses by small-RNA deep sequencing (SRDS).

Methodology/Principal Findings

SRDS was used to detect viruses in the biennial wild plant species Arctium tomentosum (woolly burdock; family Asteraceae) displaying virus-like symptoms of vein yellowing and leaf mosaic in southern Finland. Assembly of the small-RNA reads resulted in contigs homologous to Alstroemeria virus X (AlsVX), a positive/single-stranded RNA virus of genus Potexvirus (family Alphaflexiviridae), or related to negative/single-stranded RNA viruses of the genus Emaravirus. The coat protein gene of AlsVX was 81% and 89% identical to the two AlsVX isolates from Japan and Norway, respectively. The deduced, partial nucleocapsid protein amino acid sequence of the emara-like virus was only 78% or less identical to reported emaraviruses and showed no variability among the virus isolates characterized. This virus—tentatively named as Woolly burdock yellow vein virus—was exclusively associated with yellow vein and leaf mosaic symptoms in woolly burdock, whereas AlsVX was detected in only one of the 52 plants tested.

Conclusions/Significance

These results provide novel information about natural virus infections in Acrtium species and reveal woolly burdock as the first natural host of AlsVX besides Alstroemeria (family Alstroemeriaceae). Results also revealed a new virus related to the recently emerged Emaravirus genus and demonstrated applicability of SRDS to detect negative-strand RNA viruses. SRDS potentiates virus surveys of wild plants, a research area underrepresented in plant virology, and helps reveal natural reservoirs of viruses that cause yield losses in cultivated plants.     

Progress in calcium regulation in myocardial and vascular ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) has been recognized as a serious problem for therapy of cardiovascular diseases. Calcium regulation appears to be an important issue in the study of IRI. This article reviews calcium regulation in myocardial and vascular IRI, including the calcium overload and calcium sensitivity in IRI. This review is focused on the key players in Ca(2+) handling in IRI, including membrane damage resulting in increase in Ca(2+) influx, reverse-mode of Na(+)-Ca(2+) exchangers leading to increased Ca(2+) entry, the decreased activity of sarcoplasmic reticulum (SR) Ca(2+)-ATPase causing SR Ca(2+) uptake dysfunction, and increased activity of Rho kinase. These key players in Ca(2+) homeostasis will provide promising strategies and potential targets for therapy of cardiovascular IRI.     

Association between the Pro12Ala polymorphism of PPAR-γ gene and the polycystic ovary syndrome: a meta-analysis of case-control studies

Several studies have been conducted to examine the association between PPAR-γ2 Pro12Ala polymorphism and polycystic ovary syndrome (PCOS), but the results remain inconsistent. To make a more precise estimation of the relationship, a meta-analysis was performed. In the current meta-analysis, a total of 17 case-control studies, including 2176 cases and 2373 controls, were selected. Odds ratios (ORs) and 95% confidence intervals (CIs) for Pro/Ala+Ala/Ala versus Pro/Pro genotype in all population and different nationality groups, and homeostasis model assessment-insulin resistance (HOMA-IR) of different genotype were evaluated. In the overall analysis, significant association between PPAR-γ2 Pro12Ala polymorphism and reduced risk of PCOS was observed (OR=0.75; 95%CI, 0.62-0.91; p=0.003). Stratified analysis showed that significantly strong association was presented only in Europeans (OR=0.74; 95%CI, 0.60-0.90; p=0.003), but not in Asians (OR=0.86; 95%CI, 0.51-1.43; p=0.56). Additionally, carrying the Ala12 allele was not associated with HOMA-IR in PCOS patients (OR=-0.29; 95%CI, -0.82-0.24; p=0.29). This meta-analysis supported that PPAR-γ2 Pro12Ala polymorphism was capable of reducing polycystic ovary syndrome risk in Europeans, but not in Asians.     

Protective effect of L-theanine on carbon tetrachloride-induced acute liver injury in mice

We studied effects of L-theanine, a unique amino acid in tea, on carbon tetrachloride (CCl(4))-induced liver injury in mice. The mice were pre-treated orally with L-theanine (50, 100 or 200 mg/kg) once daily for seven days before CCl(4) (10 ml/kg of 0.2% CCl(4) solution in olive oil) injection. L-theanine dose-dependently suppressed the increase of serum activity of ALT and AST and bilirubin level as well as liver histopathological changes induced by CCl(4) in mice. L-theanine significantly prevented CCl(4)-induced production of lipid peroxidation and decrease of hepatic GSH content and antioxidant enzymes activities. Our further studies demonstrated that L-theanine inhibited metabolic activation of CCl(4) through down-regulating cytochrome P450 2E1 (CYP2E1). As a consequence, L-theanine inhibited oxidative stress-mediated inflammatory response which included the increase of TNF-α and IL-1β in sera, and expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in livers. CCl(4)-induced activation of apoptotic related proteins including caspase-3 and PARP in mouse livers was also prevented by L-theanine treatment. In summary, L-theanine protects mice against CCl(4)-induced acute liver injury through inhibiting metabolic activation of CCl(4) and preventing CCl(4)-induced reduction of anti-oxidant capacity in mouse livers to relieve inflammatory response and hepatocyte apoptosis.     

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway

UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H(2)O(2)) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H(2)O(2)-induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H(2)O(2)-induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D's critical role in UVB/oxidative stress-induced skin cell death.