Alcohol Dehydrogenase Accentuates Ethanol-Induced Myocardial Dysfunction and Mitochondrial Damage in Mice: Role of Mitochondrial Death Pathway

Objectives

Binge drinking and alcohol toxicity are often associated with myocardial dysfunction possibly due to accumulation of the ethanol metabolite acetaldehyde although the underlying mechanism is unknown. This study was designed to examine the impact of accelerated ethanol metabolism on myocardial contractility, mitochondrial function and apoptosis using a murine model of cardiac-specific overexpression of alcohol dehydrogenase (ADH).

Methods

ADH and wild-type FVB mice were acutely challenged with ethanol (3 g/kg/d, i.p.) for 3 days. Myocardial contractility, mitochondrial damage and apoptosis (death receptor and mitochondrial pathways) were examined.

Results

Ethanol led to reduced cardiac contractility, enlarged cardiomyocyte, mitochondrial damage and apoptosis, the effects of which were exaggerated by ADH transgene. In particular, ADH exacerbated mitochondrial dysfunction manifested as decreased mitochondrial membrane potential and accumulation of mitochondrial O₂^•−. Myocardium from ethanol-treated mice displayed enhanced Bax, Caspase-3 and decreased Bcl-2 expression, the effect of which with the exception of Caspase-3 was augmented by ADH. ADH accentuated ethanol-induced increase in the mitochondrial death domain components pro-caspase-9 and cytochrome C in the cytoplasm. Neither ethanol nor ADH affected the expression of ANP, total pro-caspase-9, cytosolic and total pro-caspase-8, TNF-α, Fas receptor, Fas L and cytosolic AIF.

Conclusions

Taken together, these data suggest that enhanced acetaldehyde production through ADH overexpression following acute ethanol exposure exacerbated ethanol-induced myocardial contractile dysfunction, cardiomyocyte enlargement, mitochondrial damage and apoptosis, indicating a pivotal role of ADH in ethanol-induced cardiac dysfunction possibly through mitochondrial death pathway of apoptosis.     

Middle and Early Upper Devonian Miospore Zonations in Eastern Yunnan and the Significance of Their Stratigraphy

The Devonian marine and non marine deposits were widely distributed in East Yunnan, where rich marine faunas and floras were present. The Middle and early Upper Devonian miospores of Eastern Yunnan were also abundant and usually well- preserved. The present paper provides both analysis of qualitative and quantitative composition development of Middle and early Upper Devonian spore assemblage in Eastern Yunnan, and a palynological zonatlon containing four successive assemblage zones: 1.Zone of Calyptosporites velatus-Rhabdosporites langii (VL); 2. Zone of Archaeozonotriletes variabilis-Calyptosporites proteus (VP); 3. Zone of Geminospora lemurata-Cristatisporites triangulatus (LT); 4. Zone of Archaeoperisaccus ovalis-Lagenicula bullosum (OB). The Middle and early Upper Devonian spore assemblages of Eastern Yunnan may be compared with those in South China and West Qinling. The spore zonation possesses stratigraphical dating of the Devonian megafloras of the region, particularly those from the Middle and Upper Devonian. The proposed spore zonation is closely compared with that erected for the Middle and early Upper Devonian of Old Sandstone Continent and adjacent Region. Based on palynological data, the reconstruction of Paleogeography and Paleoecology are discussed.     

A Novel Targeted Multi-Functional Fusion Protein Possesses Inhibitory Activities Against Bacteria, Thrombin and Platelet Aggregation

In the present study, we designed a novel targeted multi-functional fusion protein LHAD composed of LL-37, FXa recognition peptide, hirudin-12-residue, AAP, and RGD peptide. It was expressed in the Pichia pastoris GS115 strain and purified by affinity chromatography. The in vitro studies suggested that the novel designed protein exhibited antibacterial activity, anti-platelet aggregation and anti-thrombin activities. Moreover, the capability of anti-thrombin was significantly increased compared to that of natural hirudin. Our study may provide a potential approach to design multi-functional drugs for the prevention and management of thrombosis.     

Promising effects of the 4HPR-BSO combination in neuroblastoma monolayers and spheroids

To enhance the efficacy of fenretinide (4HPR)-induced reactive oxygen species (ROS) in neuroblastoma, 4HPR was combined with buthionine sulfoximine (BSO), an inhibitor of glutathione (GSH) synthesis, in neuroblastoma cell lines and spheroids, the latter being a three-dimensional tumor model. 4HPR exposure (2.5-10 μM, 24 h) resulted in ROS induction (114-633%) and increased GSH levels (68-120%). A GSH depletion of 80% of basal levels was observed in the presence of BSO (25-100 μM, 24 h). The 4HPR-BSO combination resulted in slightly increased ROS levels (1.1- to 1.3-fold) accompanied by an increase in cytotoxicity (110-150%) compared to 4HPR treatment alone. A correlation was observed between the ROS-inducing capacity of each cell line and the increase in cytotoxicity induced by 4HPR-BSO compared to 4HPR. No significant correlation between baseline antioxidant levels and sensitivity to 4HPR or BSO was observed. In spheroids, 4HPR-BSO induced a strong synergistic growth retardation and induction of apoptosis. Our data show that BSO increased the cytotoxic effects of 4HPR in neuroblastoma monolayers and spheroids in ROS-producing cell lines. This indicates that the 4HPR-BSO combination might be a promising new strategy in the treatment of neuroblastoma.     

Immunomodulatory dendritic cells inhibit Th1 responses and arthritis via different mechanisms

Dendritic cells (DCs) are professional APCs which have the unique ability to present both foreign and self-Ags to T cells and steer the outcome of immune responses. Because of these characteristics, DCs are attractive vehicles for the delivery of therapeutic vaccines. Fully matured DCs are relatively well-defined and even used in clinical trials in cancer. DCs also have the potential to influence the outcome of autoimmunity by modulating the underlying autoimmune response. To gain a better appreciation of the abilities and mechanisms by which immunomodulatory DCs influence the outcome of T cell responses, we studied several immunomodulatory DCs (TNF-, IL-10-, or dexamethasone-stimulated bone marrow-derived DCs) side by side for their ability to modulate T cell responses and autoimmune diseases. Our data show that these differentially modulated DCs display a different composition of molecules involved in T cell activation. Although, all DC subsets analyzed were able to inhibit the induction of collagen-induced arthritis, the modulation of the underlying immune response was different. Vaccination with TNF- or IL-10-modulated DCs altered the Th1/Th2 balance as evidenced by the induction of IL-5- and IL-10-secreting T cells and the concomitant reduction of the IgG2a-IgG1 ratio against the immunizing Ag. In contrast, DCs modulated with dexamethasone did not affect the ratio of IL-5-producing vs IFN-gamma-producing T cells and tended to affect the Ab response in a nonspecific manner. These data indicate that distinct mechanisms can be used by distinct DC subsets to change the outcome of autoimmunity.     

S-decyl-glutathione nonspecifically stimulates the ATPase activity of the nucleotide-binding domains of the human multidrug resistance-associated protein, MRP1 (ABCC1).

The human multidrug resistance-associated protein(MRP1) is an ATP-dependent efflux pump that transports anionic conjugates, and hydrophobic compounds in a glutathione dependent manner. Similar to the other, well-characterized multidrug transporter P-gp, MRP1 comprises two nucleotide-binding domains (NBDs) in addition to transmembrane domains. However, whereas the NBDs of P-gp have been shown to be functionally equivalent, those of MRP1 differ significantly. The isolated NBDs of MRP1 have been characterized in Escherichia coli as fusions with either the glutathione-S-transferase (GST) or the maltose-binding domain (MBP). The nonfused NBD1 was obtained by cleavage of the fusion protein with thrombin. The GST-fused forms of NBD1 and NBD2 hydrolyzed ATP with an apparent K(m) of 340 microm and a V(max) of 6.0 nmol P(I) x mg-1 x min-1, and a K(m) of 910 microm ATP and a V(max) of 7.5 nmol P(I) x mg-1 x min-1, respectively. Remarkably, S-decyl-glutathione, a conjugate specifically transported by MRP1 and MRP2, was able to stimulate the ATPase activities of the isolated NBDs more than 2-fold in a concentration-dependent manner. However,the stimulation of the ATPase activity was found to coincide with the formation of micelles by S-decyl-glutathione. Equivalent stimulation of ATPase activity could be obtained by surfactants with similar critical micelle concentrations.     

基于栖息地斑块尺度的青弋江河源溪流鱼类群落的时空格局

确定鱼类的栖息地利用格局是研究物种与环境关系的基础, 也是鱼类多样性保护和管理的必要前提。目前, 有关溪流鱼类群落的栖息地斑块利用格局尚存在争议。基于2012年9月至2013年8月对青弋江河源溪流的逐月调查数据, 初步研究了鱼类群落的栖息地斑块利用格局, 着重在栖息地斑块尺度上解析了鱼类群落的时空变化规律。主要研究结果显示, 深潭和急滩2类斑块间的底质、流速、水深、溶氧栖息地因子显著差异, 且深潭斑块的环境稳定性高于急滩。研究共采集鱼类15种, 其中鲤科鱼类8种, 占采集物种数50%以上。基于鱼类物种存在与否的不连续变量的分析结果显示, 鱼类物种组成的斑块间和月份间变化均不具显著性。但是, 基于鱼类物种多度的连续变量的分析结果显示, 鱼类群落结构存在有显著的斑块间变化和时间动态; 就斑块间变化而言, 原缨口鳅(Vanmanenia stenosoma)在急滩斑块中的多度更高, 而宽鳍 (Zacco platypus)、光唇鱼(Acrossocheilus fasciatus)和尖头 (Phoxinus oxycephalus)等其他关键物种则在深潭中具有更高多度。深潭斑块的鱼类物种数显著高于急滩, 但2类斑块间的个体数无显著差异。深潭斑块的鱼类物种数较稳定, 而个体数月变化显著, 可能与鱼类繁殖和群体补充以及越冬死亡等有关; 急滩鱼类物种数和个体数的月变化均显著, 除了与鱼类群体补充和越冬死亡有关以外, 还可能受越冬时栖息地斑块选择变化的影响。上述结果表明, 在栖息地斑块空间尺度上, 由于研究区域内大多数物种在栖息地斑块选择上无明显的特化性, 深潭和急滩斑块间鱼类的物种组成分布不符合前人所报道的生境-共位群格局, 但区域内常见种多度的变化可引起鱼类群落结构的斑块间差异和季节动态。       

RETRACTED ARTICLE: Mast cells are the main interleukin 17-positive cells in anticitrullinated protein antibody-positive and -negative rheumatoid arthritis and osteoarthritis synovium

Introduction  

Mast cells have been implicated to play a functional role in arthritis, especially in autoantibody-positive disease. Among the cytokines involved in rheumatoid arthritis (RA), IL-17 is an important inflammatory mediator. Recent data suggest that the synovial mast cell is a main producer of IL-17, although T cells have also been implicated as prominent IL-17 producers as well. We aimed to identify IL-17 expression by mast cells and T cells in synovium of arthritis patients.