International Journal of Biological Sciences http://www.biolsci.org International Journal of Biological Sciences RSS feed -- Volume 8 en-us Tue, 24 Jan 2012 04:00:00 GMT Tue, 24 Jan 2012 04:00:00 GMT http://www.biolsci.org/v08p0289.htm Activated β-catenin Forces N2A Cell-derived Neurons Back to Tumor-like Neuroblasts and Positively Correlates with a Risk for Human Neuroblastoma http://www.biolsci.org/v08p0289.htm Neuroblastoma is an embryonic malignancy arising from neuroblasts. The mechanisms that regulate the origination of neuroblastoma are still not very clear. In this study, we revealed that 6-bromoindirubin 3'-oxime (BIO), a specific GSK-3β inhibitor, promoted N2A cells-derived neurons to become tumor-like neuroblasts. Moreover, constitutively activated β-catenin (S33Y) also promoted this process, whereas, silencing endogenous expression of β-catenin abolished BIO-induced effects. These results implicated the potential relationship between the Wnt/β-catenin signaling and neuroblastoma formation. Indeed, we found that the amount of β-catenin in nucleus, which indicated the activation of Wnt/β-catnin signaling, was accumulated in human neuroblastoma specimens and positively correlated with clinical risk of neuroblastoma. These results give us a new sight into the neuroblastoma initiation and progression, and provide a potential drug target for neuroblastoma treatment.

]]> Feng Zhi, Guangming Gong, Yan Xu, Yan Zhu, Die Hu, Yilin Yang, Yiqiao Hu Ivyspring International Publisher 8 2 289 297 2012-1-23 Short Research Communication http://www.biolsci.org/v08p0272.htm TGF-β and BMP Signaling in Osteoblast Differentiation and Bone Formation http://www.biolsci.org/v08p0272.htm Transforming growth factor-beta (TGF-β)/bone morphogenic protein (BMP) signaling is involved in a vast majority of cellular processes and is fundamentally important throughout life. TGF-β/BMPs have widely recognized roles in bone formation during mammalian development and exhibit versatile regulatory functions in the body. Signaling transduction by TGF-β/BMPs is specifically through both canonical Smad-dependent pathways (TGF-β/BMP ligands, receptors and Smads) and non-canonical Smad-independent signaling pathway (e.g. p38 mitogen-activated protein kinase pathway, MAPK). Following TGF-β/BMP induction, both the Smad and p38 MAPK pathways converge at the Runx2 gene to control mesenchymal precursor cell differentiation. The coordinated activity of Runx2 and TGF-β/BMP-activated Smads is critical for formation of the skeleton. Recent advances in molecular and genetic studies using gene targeting in mice enable a better understanding of TGF-β/BMP signaling in bone and in the signaling networks underlying osteoblast differentiation and bone formation. This review summarizes the recent advances in our understanding of TGF-β/BMP signaling in bone from studies of genetic mouse models and human diseases caused by the disruption of TGF-β/BMP signaling. This review also highlights the different modes of cross-talk between TGF-β/BMP signaling and the signaling pathways of MAPK, Wnt, Hedgehog, Notch, and FGF in osteoblast differentiation and bone formation.

]]> Guiqian Chen, Chuxia Deng, Yi-Ping Li Ivyspring International Publisher 8 2 272 288 2012-1-21 Review http://www.biolsci.org/v08p0265.htm Measurement of Hepatic Protein Fractional Synthetic Rate with Stable Isotope Labeling Technique in Thapsigargin Stressed HepG2 Cells http://www.biolsci.org/v08p0265.htm Severe burn-induced liver damage and dysfunction is associated with endoplasmic reticulum (ER) stress. ER stress has been shown to regulate global protein synthesis. In the current study, we induced ER stress in vitro and estimated the effect of ER stress on hepatic protein synthesis. The aim was two-fold: (1) to establish an in vitro model to isotopically measure hepatic protein synthesis and (2) to evaluate protein fractional synthetic rate (FSR) in response to ER stress. Human hepatocellular carcinoma cells (HepG2) were cultured in medium supplemented with stable isotopes 1,2-13C2-glycine and L-[ring-13C6]phenylalanine. ER stress was induced by exposing the cells to 100 nM of thapsigargin (TG). Cell content was collected from day 0 to 14. Alterations in cytosolic calcium were measured by calcium imaging and ER stress markers were confirmed by Western blotting. The precursor and product enrichments were detected by GC-MS analysis for FSR calculation. We found that the hepatic protein FSR were 0.97±0.02 and 0.99±0.05%/hr calculated from 1,2-13C2-glycine and L-[ring-13C6]phenylalanine, respectively. TG depleted ER calcium stores and induced ER stress by upregulating p-IRE-1 and Bip. FSR dramatically decreased to 0.68±0.03 and 0.60±0.06%/hr in the TG treatment group (p<0.05, vs. control). TG-induced ER stress inhibited hepatic protein synthesis. The stable isotope tracer incorporation technique is a useful method for studying the effects of ER stress on hepatic protein synthesis.

]]> Juquan Song, Xiao-jun Zhang, Darren Boehning, Natasha C. Brooks, David N. Herndon, Marc G. Jeschke Ivyspring International Publisher 8 2 265 271 2012-1-20 Research Paper http://www.biolsci.org/v08p0258.htm An Updated Nomenclature for Keratin-Associated Proteins (KAPs) http://www.biolsci.org/v08p0258.htm Most protein in hair and wool is of two broad types: keratin intermediate filament-forming proteins (commonly known as keratins) and keratin-associated proteins (KAPs). Keratin nomenclature was reviewed in 2006, but the KAP nomenclature has not been revised since 1993. Recently there has been an increase in the number of KAP genes (KRTAPs) identified in humans and other species, and increasingly reports of variation in these genes. We therefore propose that an updated naming system is needed to accommodate the complexity of the KAPs. It is proposed that the system is founded in the previous nomenclature, but with the abbreviation sp-KAPm-nL*x for KAP proteins and sp-KRTAPm-n(p/L)*x for KAP genes. In this system “sp” is a unique letter-based code for different species as described by the protein knowledge-based UniProt. “m” is a number identifying the gene or protein family, “n” is a constituent member of that family, “p” signifies a pseudogene if present, “L” if present signifies “like” and refers to a temporary “place-holder” until the family is confirmed and “x” signifies a genetic variant or allele. We support the use of non-italicised text for the proteins and italicised text for the genes.

This nomenclature is not that different to the existing system, but it includes species information and also describes genetic variation if identified, and hence is more informative. For example, GenBank sequence JN091630 would historically have been named KRTAP7-1 for the gene and KAP7-1 for the protein, but with the proposed nomenclature would be SHEEP-KRTAP7-1*A and SHEEP-KAP7-1*A for the gene and protein respectively. This nomenclature will facilitate more efficient storage and retrieval of data and define a common language for the KAP proteins and genes from all mammalian species.

]]> Hua Gong, Huitong Zhou, Grant W. McKenzie, Zhidong Yu, Stefan Clerens, Jolon M. Dyer, Jeffrey E. Plowman, Mathew W. Wright, Reena Arora, C. Simon Bawden, Yulin Chen, Jinquan Li, Jonathan G. H. Hickford Ivyspring International Publisher 8 2 258 264 2012-1-12 Mini-review http://www.biolsci.org/v08p0249.htm Interleukin-22 Ameliorates Cerulein-Induced Pancreatitis in Mice by Inhibiting the Autophagic Pathway http://www.biolsci.org/v08p0249.htm Pancreatitis occurs when digestive enzymes are activated in the pancreas. Severe pancreatitis has a 10-30% mortality rate. No specific treatments for pancreatitis exist now. Here, we discovered that interleukin-22 (IL-22) may have therapeutic potential in treating acute and chronic pancreatitis. Wild-type and IL-22 knockout mice were equally susceptible to cerulein-induced acute and chronic pancreatitis, whereas liver-specific IL-22 transgenic mice were completely resistant to cerulein-induced elevation of serum digestive enzymes, pancreatic necrosis and apoptosis, and inflammatory cell infiltration. Treatment of wild-type mice with recombinant IL-22 or adenovirus IL-22 markedly attenuated the severity of cerulein-induced acute and chronic pancreatitis. Mechanistically, we show that the protective effect of IL-22 on pancreatitis was mediated via the induction of Bcl-2 and Bcl-XL, which bind to Beclin-1 and subsequently inhibit autophagosome formation to ameliorate pancreatitis. In conclusion, IL-22 ameliorates cerulein-induced pancreatitis by inhibiting the autophagic pathway. IL-22 could be a promising therapeutic drug to treat pancreatitis.

]]> Dechun Feng, Ogyi Park, Svetlana Radaeva, Hua Wang, Shi Yin, Xiaoni Kong, Mingquan Zheng, Sam Zakhari, Jay K. Kolls, Bin Gao Ivyspring International Publisher 8 2 249 257 2012-1-6 Research Paper http://www.biolsci.org/v08p0236.htm Simvastatin Modulates Remodeling of Kv4.3 Expression in Rat Hypertrophied Cardiomyocytes http://www.biolsci.org/v08p0236.htm Objectives: Hypertrophy has been shown to be associated with arrhythmias which can be caused by abnormal remodeling of the Kv4-family of transient potassium channels. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) have recently been shown to exert pleiotropic protective effects in cardiovascular diseases, including anti-arrhythmias. It is hypothesized that remodeling of Kv4.3 occurs in rat hypertrophied cardiomyocytes and is regulated by simvastatin.

Methods: Male Sprague-Dawley rats and neonatal rat ventricular myocytes (NRVMs) underwent abdominal aortic banding (AAB) for 7 weeks and angiotensin II (AngII) treatment, respectively, to induce cardiac hypertrophy. Kv4.3 expression by NRVMs and myocardium (subepicardial and subendocardial) in the left ventricle was measured. The transient outward potassium current (Ito) of NRVMs was recorded using a whole-cell patch-clamp method.

Results: Expression of the Kv4.3 transcript and protein was significantly reduced in myocardium (subepicardial and subendocardial) in the left ventricle and in NRVMs. Simvastatin partially prevented the reduction of Kv4.3 expression in NRVMs and subepicardial myocardium but not in the subendocardial myocardium. Hypertrophied NRVMs exhibited a significant reduction in the Ito current and this effect was partially reversed by simvastatin.

Conclusions: Simvastatin alleviated the reduction of Kv4.3 expression, Ito currents in hypertrophied NRVMs and alleviated the reduced Kv4.3 expression in subepicardial myocardium from the hypertrophied left ventricle. It can be speculated that among the pleiotropic effects of simvastatin, the anti-arrhythmia effect is partly mediated by its effect on Kv4.3.

]]> Feifei Su, Miaoqian Shi, Zhiqiang Yan, Dongbo Ou, Juntang Li, Zifan Lu, Qiangsun Zheng Ivyspring International Publisher 8 2 236 248 2012-1-6 Research Paper http://www.biolsci.org/v08p0228.htm The Pro-inflammatory Role of TGFβ1: A Paradox? http://www.biolsci.org/v08p0228.htm TGFβ1 was initially identified as a potent chemotactic cytokine to initiate inflammation, but the autoimmune phenotype seen in TGFβ1 knockout mice reversed the dogma of TGFβ1 being a pro-inflammatory cytokine to predominantly an immune suppressor. The discovery of the role of TGFβ1 in Th17 cell activation once again revealed the pro-inflammatory effect of TGFβ1. We developed K5.TGFβ1 mice with latent human TGFβ1 overexpression targeted to epidermal keratinocytes by keratin 5. These transgenic mice developed significant skin inflammation. Further studies revealed that inflammation severity correlated with switching TGFβ1 transgene expression on and off, and genome wide expression profiling revealed striking similarities between K5.TGFβ1 skin and human psoriasis, a Th1/Th17-associated inflammatory skin disease. Our recent study reveals that treatments alleviating inflammatory skin phenotypes in this mouse model reduced Th17 cells, and antibodies against IL-17 also lessen the inflammatory phenotype. Examination of inflammatory cytokines/chemokines affected by TGFβ1 revealed predominantly Th1-, Th17-related cytokines in K5.TGFβ1 skin. However, the finding that K5.TGFβ1 mice also express Th2-associated inflammatory cytokines under certain pathological conditions raises the possibility that deregulated TGFβ signaling is involved in more than one inflammatory disease. Furthermore, activation of both Th1/Th17 cells and regulatory T cells (Tregs) by TGFβ1 reversely regulated by IL-6 highlights the dual role of TGFβ1 in regulating inflammation, a dynamic, context and organ specific process. This review focuses on the role of TGFβ1 in inflammatory skin diseases.

]]> Gangwen Han, Fulun Li, Tej Pratap Singh, Peter Wolf, Xiao-Jing Wang Ivyspring International Publisher 8 2 228 235 2012-1-1 Review http://www.biolsci.org/v08p0214.htm Contrasting Cellularity and Fatty Acid Composition in Fat Depots from Alentejana and Barrosã Bovine Breeds Fed High and Low Forage Diets http://www.biolsci.org/v08p0214.htm During the finishing phase of bovines, large amounts of subcutaneous and visceral fats are deposited leading to production inefficiencies with major impact on meat quality. A better understanding of the cellularity features of the main fat depots could provide strategies for adipose tissue manipulation. This study assessed the effect of feeding diets with distinct forage to concentrate ratios on the cellularity of two fat depots of beef cattle and their implications on the fatty acid profile. Thus, two phylogenetically distant Portuguese bovine breeds, Alentejana and Barrosã, were selected. The results did not show differences in subcutaneous fat deposition nor in visceral fat depots partitioning. Plasma adipokines concentration failed to show a consistent relationship with fatness, as leptin remained constant in all experimental groups, whereas interleukin-6 was influenced by breed. Fat depot seems to determine the area and number of adipocytes, with larger adipocytes and a lower number of cells in subcutaneous fat than in mesenteric fat. Neither breed nor diet influenced adipocytes area and number. The contents of total fatty acids, partial sums of fatty acids and conjugated linoleic acid isomeric profile were affected by breed and fat depot. The incorporation of saturated fatty acids (SFA), trans fatty acids, polyunsaturated fatty acids (PUFA) and branched chain fatty acids (BCFA) was higher in mesenteric fat depot, whereas subcutaneous fat depot had greater percentages of monounsaturated fatty acids (MUFA). In addition, SFA and MUFA proportions seem to be breed-related. In spite of the less relevant role of diet, the percentages of PUFA and BCFA were influenced by this factor. Under these experimental conditions, the effect of fat depot on cellularity and fatty acid composition prevails over breed or diet, as reinforced by the principal component analysis.

]]> Ana S.H. Costa, Paula A. Lopes, Marta Estevão, Susana V. Martins, Susana P. Alves, Rui M.A. Pinto, Hugo Pissarra, Jorge J. Correia, Mário Pinho, Carlos M.G.A. Fontes, José A.M. Prates Ivyspring International Publisher 8 2 214 227 2012-1-1 Research Paper http://www.biolsci.org/v08p0195.htm TGFβ Signaling and Cardiovascular Diseases http://www.biolsci.org/v08p0195.htm Transforming growth factor β (TGFβ) family members are involved in a wide range of diverse functions and play key roles in embryogenesis, development and tissue homeostasis. Perturbation of TGFβ signaling may lead to vascular and other diseases. In vitro studies have provided evidence that TGFβ family members have a wide range of diverse effects on vascular cells, which are highly dependent on cellular context. Consistent with these observations genetic studies in mice and humans showed that TGFβ family members have ambiguous effects on the function of the cardiovascular system. In this review we discuss the recent advances on TGFβ signaling in (cardio)vascular diseases, and describe the value of TGFβ signaling as both a disease marker and therapeutic target for (cardio)vascular diseases.

]]> Evangelia Pardali, Peter ten Dijke Ivyspring International Publisher 8 2 195 213 2012-1-1 Review http://www.biolsci.org/v08p0187.htm The Adhesion Modulating Properties of Tenascin-W http://www.biolsci.org/v08p0187.htm Tenascins are extracellular matrix glycoproteins associated with cell motility, proliferation and differentiation. Tenascin-C inhibits cell spreading by binding to fibronectin; tenascin-R and tenascin-X also have anti-adhesive properties in vitro. Here we have studied the adhesion modulating properties of the most recently characterized tenascin, tenascin-W. C2C12 cells, a murine myoblast cell line, will form broad lamellipodia with stress fibers and focal adhesion complexes after culture on fibronectin. In contrast, C2C12 cells cultured on tenascin-W fail to spread and form stress fibers or focal adhesion complexes, and instead acquire a multipolar shape with short, actin-tipped pseudopodia. The same stellate morphology is observed when C2C12 cells are cultured on a mixture of fibronectin and tenascin-W, or on fibronectin in the presence of soluble tenascin-W. Tenascin-W combined with fibronectin also inhibits the spreading of mouse embryo fibroblasts when compared with cells cultured on fibronectin alone. The similarity between the adhesion modulating effects of tenascin-W and tenascin-C in vitro led us to study the possibility of tenascin-W compensating for tenascin-C in tenascin-C knockout mice, especially during epidermal wound healing. Dermal fibroblasts harvested from a tenascin-C knockout mouse express tenascin-W, but dermal fibroblasts taken from a wild type mouse do not. However, there is no upregulation of tenascin-W in the dermis of tenascin-C knockout mice, or in the granulation tissue of skin wounds in tenascin-C knockout animals. Similarly, tenascin-X is not upregulated in early wound granulation tissue in the tenascin-C knockout mice. Thus, tenascin-W is able to inhibit cell spreading in vitro and it is upregulated in dermal fibroblasts taken from the tenascin-C knockout mouse, but neither it nor tenascin-X are likely to compensate for missing tenascin-C during wound healing.

]]> Florence Brellier, Enrico Martina, Matthias Chiquet, Jacqueline Ferralli, Michael van der Heyden, Gertraud Orend, Johannes C. Schittny, Ruth Chiquet-Ehrismann, Richard P. Tucker Ivyspring International Publisher 8 2 187 194 2011-12-20 Short Research Communication http://www.biolsci.org/v08p0171.htm The Murine Caecal MicroRNA Signature Depends on the Presence of the Endogenous Microbiota http://www.biolsci.org/v08p0171.htm The intestinal messenger RNA expression signature is affected by the presence and composition of the endogenous microbiota, with effects on host physiology. The intestine is also characterized by a distinctive micronome. However, it is not known if microbes also impact intestinal gene expression epigenetically. We investigated if the murine caecal microRNA expression signature depends on the presence of the microbiota, and the potential implications of this interaction on intestinal barrier function. Three hundred and thirty four microRNAs were detectable in the caecum of germ-free and conventional male mice and 16 were differentially expressed, with samples from the two groups clustering separately based on their expression patterns. Through a combination of computational and gene expression analyses, including the use of our curated list of 527 genes involved in intestinal barrier regulation, 2,755 putative targets of modulated microRNAs were identified, including 34 intestinal barrier-related genes encoding for junctional and mucus layer proteins and involved in immune regulation. This study shows that the endogenous microbiota influences the caecal microRNA expression signature, suggesting that microRNA modulation is another mechanism through which commensal bacteria impact the regulation of the barrier function and intestinal homeostasis. Through microRNAs, the gut microbiota may impinge a much larger number of genes than expected, particularly in diseases where its composition is altered. In this perspective, abnormally expressed microRNAs could be considered as novel therapeutic targets.

]]> Natasha Singh, Elize A. Shirdel, Levi Waldron, Regan-Heng Zhang, Igor Jurisica, Elena M. Comelli Ivyspring International Publisher 8 2 171 186 2011-12-19 Research Paper http://www.biolsci.org/v08p0159.htm The Olfactory Co-receptor Orco from the Migratory Locust (Locusta migratoria) and the Desert Locust (Schistocerca gregaria): Identification and Expression pattern http://www.biolsci.org/v08p0159.htm In locusts, olfaction plays a crucial role for initiating and controlling behaviours, including food seeking and aggregation with conspecifics, which underlie the agricultural pest capacity of the animals. In this context, the molecular basis of olfaction in these insects is of particular interest. Here, we have identified genes of two orthopteran species, Locusta migratoria and Schistocera gregaria, which encode the olfactory receptor co-receptor (Orco). It was found that the sequences of LmigOrco and SgreOrco share a high degree of identity to each other and also to Orco proteins from different insect orders. The Orco-expressing cells in the antenna of S. gregaria and L. migratoria were visualized by in situ hybridization. Orco expression could be assigned to clusters of cells in sensilla basiconica and few cells in sensilla trichodea, most likely representing olfactory sensory neurons. No Orco-positive cells were detected in sensilla coeloconica and sensilla chaetica. Orco expression was found already in all nymphal stages and was verified in some other tissues which are equipped with chemosensory hairs (mouthparts, tarsi, wings). Together, the results support the notion for a decisive role of Orco in locust olfaction.

]]> Ying Yang, Jürgen Krieger, Long Zhang, Heinz Breer Ivyspring International Publisher 8 2 159 170 2011-12-13 Research Paper http://www.biolsci.org/v08p0150.htm Matrine Inhibits Pacing Induced Atrial Fibrillation by Modulating IKM3 and ICa-L http://www.biolsci.org/v08p0150.htm Aim: To elucidate the protective effects of Matrine on atrial fibrillation (AF) induced by electric pacing in mice and underlying molecular and ion channel mechanisms.

Methods: AF was introduced by electric pacing in mice and the incidence and duration of AF were evaluated. Functional expression of M3 receptor (M3-R) and Cav1.2 were explored by western and Real-time PCR, action potential (AP) and the density of (IKM3) L-type calcium channel (ICa-L) were both recorded using whole-cell patch in isolated atrial cardiomyocytes.

Results: In control group, incidence and duration of AF induced by electric pacing were 50 ± 17% and 3.68 ± 1.84 s, respectively; after application of carbachol 50 µg/kg both incidence and duration of AF were significantly increased to 86 ± 24% and 65.2 ± 29.0 s. Compared with control group, pretreatment of Matrine for 15 days significantly reduced AF incidence and duration in dose-dependent manner. Atrial membrane-protein expression of M3-R was decreased and membrane Cav1.2 expression was up-regulated. In single Matrine-treated atrial cardiomyocyte the density of IKM3 was significantly decreased by 39% as well compared with control group, P < 0.05, whereas, ICa-L density of atrium was increased by 40%.

Conclusion: These data demonstrated at the first time that the anti-AF effects of Matrine may due, at least in part, to down-regulation of IKM3 density and M3-R expression and up-regulation of ICa-L density and α1C/Cav1.2 expression.

]]> Yuhong Zhou, Wei Xu, Ruyi Han, Jiaying Zhou, Zhenwei Pan, Huo Rong, Junnan Li, Changqing Xu, Guofen Qiao, Yanjie Lu Ivyspring International Publisher 8 1 150 158 2011-12-9 Research Paper http://www.biolsci.org/v08p0139.htm Altered Antioxidant Status and Increased Lipid Per-Oxidation in Seminal Plasma of Tunisian Infertile Men http://www.biolsci.org/v08p0139.htm Human seminal plasma is a natural reservoir of antioxidants that protect spermatozoa from oxidative damages. There is evidence in literature supports the fact that impairments in seminal antioxidant and lipid per-oxidation status play important roles in the physiopathology of male infertility. Our present study forms the first one which was carried out in Tunisia. We evaluated the antioxidant status in the seminal plasma of 120 infertile men programmed to In Vitro Fertilization (IVF) for the first tentative. Patients were characterized by an idiopathic infertility. They were divided into three groups: normozoospermics who were considered as controls (n=40), asthenozoospermics (Astheno; n=45) and oligoasthenoteratozoospermics (OAT; n=35). Seminal activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) and the levels of glutathione (GSH), zinc (Zn) and malondialdehyde (MDA) were measured. With the significant increase of the seminal activities of SOD and GPX in normozoospermics group, there were positive correlations observed between this enzymes and sperm quality. Also, significant elevated rates of seminal zinc and GSH were observed in control group, but there was contradictory associations reflecting the effects of these antioxidants on semen parameters. However, we noted significant increase of MDA levels in groups with abnormal seminogram. We showed negative associations between this per-oxidative marker and sperm parameters. These results obviously suggested that impairment on seminal antioxidants is an important risk factor for low sperm quality associated to idiopathic infertility and as a result can lead to poor IVF outcome.

]]> Fatma Atig, Monia Raffa, Habib Ben Ali, Kerkeni Abdelhamid, Ali Saad, Mounir Ajina Ivyspring International Publisher 8 1 139 149 2011-12-8 Research Paper http://www.biolsci.org/v08p0125.htm Molecular Cloning and Characterization of Ecdysone oxidase and 3-dehydroecdysone-3α-reductase Involved in the Ecdysone Inactivation Pathway of Silkworm, Bombyx mori http://www.biolsci.org/v08p0125.htm Molting hormone (ecdysteroid) is one of the most important hormones in insects. The synthesis and inactivation of the ecdysteroid regulate the developmental process of insects. A major pathway of ecdysone inactivation is that ecdysone is converted to 3-dehydroecdysone, and then further to 3-epiecdysone in insects. Two enzymes (ecdysone oxidase: EO and 3DE-3α-reductase) participate in this pathway. In this study, based on the previously characterized cDNAs in Spodoptera littoralis, we cloned and characterized EO and 3DE-3α-reductase genes in the silkworm, Bombyx mori. The heterologously expressed proteins of the two genes in yeast showed the ecdysone oxidase and 3DE-3α-reductase activities, respectively. Expression of BmEO was only detected in the midgut at transcriptional and translational levels. We also localized EO within the midgut goblet cell cavities. For Bm3DE-3α-reductase gene, RT-PCR and western blot showed that it was expressed in the midgut and the Malpighian tubules. Moreover, we localized 3DE-3α-reductase within the midgut goblet cell cavities and the cytosol of principal cells of the Malpighian tubules. These two genes have similar expression profiles during different developmental stages. Both genes were highly expressed at the beginning of the 5th instar, and remained a relative low level during the feeding stage, and then were highly expressed at the wandering stage. All these results showed that the profiles of the two genes were well correlated with the ecdysteroid titer. The functional characterization of the enzymes participating in ecdysone inactivation in the silkworm provides hints for the artificial regulation of the silkworm development and biological control of pests.

]]> Wei Sun, Yi-Hong Shen, Deng-Wei Qi, Zhong-Huai Xiang, Ze Zhang Ivyspring International Publisher 8 1 125 138 2011-12-8 Research Paper http://www.biolsci.org/v08p0124.htm Correction: Molecular Characterization of Transcriptome-wide Interactions between Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and Porcine Alveolar Macrophages in vivo http://www.biolsci.org/v08p0124.htm Ping Zhou, Shanli Zhai, Xiang Zhou, Ping Lin, Tengfei Jiang, Xueying Hu, Yunbo Jiang, Bin Wu, Qingde Zhang, Xuewen Xu, Jin-ping Li, Bang Liu Ivyspring International Publisher 8 1 124 124 2011-12-1 Erratum http://www.biolsci.org/v08p0118.htm Immune-related MicroRNAs are Abundant in Breast Milk Exosomes http://www.biolsci.org/v08p0118.htm Breast milk is a complex liquid rich in immunological components that affect the development of the infant's immune system. Exosomes are membranous vesicles of endocytic origin that are found in various body fluids and that can mediate intercellular communication. MicroRNAs (miRNAs), a well-defined group of non-coding small RNAs, are packaged inside exosomes in human breast milk. Here, we identified 602 unique miRNAs originating from 452 miRNA precursors (pre-miRNAs) in human breast milk exosomes using deep sequencing technology. We found that, out of 87 well-characterized immune-related pre-miRNAs, 59 (67.82%) are presented and enriched in breast milk exosomes (P < 10-16, χ2 test). In addition, compared with exogenous synthetic miRNAs, these endogenous immune-related miRNAs are more resistant to relatively harsh conditions. It is, therefore, tempting to speculate that these exosomal miRNAs are transferred from the mother's milk to the infant via the digestive tract, and that they play a critical role in the development of the infant immune system.

]]> Qi Zhou, Mingzhou Li, Xiaoyan Wang, Qingzhi Li, Tao Wang, Qi Zhu, Xiaochuan Zhou, Xin Wang, Xiaolian Gao, Xuewei Li Ivyspring International Publisher 8 1 118 123 2011-11-29 Research Paper http://www.biolsci.org/v08p0108.htm Identification of Ghrelin Receptor Blocker, D-[Lys3] GHRP-6 as a CXCR4 Receptor Antagonist http://www.biolsci.org/v08p0108.htm [D-Lys3]-Growth Hormone Releasing Peptide-6 (DLS) is widely utilized in vivo and in vitro as a selective ghrelin receptor (GHS-R) antagonist. Unexpectedly, we identified that DLS also has the ability to block CXCL12 binding and activity through CXCR4 on T cells and peripheral blood mononuclear cells (PBMCs). Moreover, as CXCR4 has been shown to act as a major co-receptor for HIV-1 entry into CD4 positive host cells, we have also found that DLS partially blocks CXCR4-mediated HIV-1 entry and propagation in activated human PBMCs. These data demonstrate that DLS is not the specific and selective antagonist as thought for GHS-R1a and appears to have additional effects on the CXCR4 chemokine receptor. Our findings also suggest that structural analogues that mimic DLS binding properties may also have properties of blocking HIV infectivity, CXCR4 dependent cancer cell migration and attenuating chemokine-mediated immune cell trafficking in inflammatory disorders.

]]> Kalpesh Patel, Vishwa Deep Dixit, Jun Ho Lee, Jie Wan Kim, Eric M. Schaffer, Dzung Nguyen, Dennis D. Taub Ivyspring International Publisher 8 1 108 117 2011-11-26 Research Paper http://www.biolsci.org/v08p0093.htm The Complete Mitochondrial Genome of the Damsel Bug Alloeorhynchus bakeri (Hemiptera: Nabidae) http://www.biolsci.org/v08p0093.htm The complete sequence of the mitochondrial DNA (mtDNA) of the damsel bug, Alloeorhynchus bakeri, has been completed and annotated in this study. It represents the first sequenced mitochondrial genome of heteropteran family Nabidae. The circular genome is 15, 851 bp in length with an A+T content of 73.5%, contains the typical 37 genes that are arranged in the same order as that of the putative ancestor of hexapods. Nucleotide composition and codon usage are similar to other known heteropteran mitochondrial genomes. All protein-coding genes (PCGs) use standard initiation codons (methionine and isoleucine), except COI, which started with TTG. Canonical TAA and TAG termination codons are found in eight protein-coding genes, the remaining five (COI, COII, COIII, ND5, ND1) have incomplete termination codons (T or TA). PCGs of two strands present opposite CG skew which is also reflected by the nucleotide composition and codon usage. All tRNAs have the typical clover-leaf structure, except the dihydrouridine (DHU) arm of tRNASer (AGN) which forms a simple loop as known in many other metazoa. Secondary structure models of the ribosomal RNA genes of A. bakeri are presented, similar to those proposed for other insect orders. There are six domains and 45 helices and three domains and 27 helices in the secondary structures of rrnL and rrnS, respectively. The major non-coding region (also called control region) between the small ribosomal subunit and the tRNAIle gene includes two special regions. The first region includes four 133 bp tandem repeat units plus a partial copy of the repeat (28 bp of the beginning), and the second region at the end of control region contains 4 potential stem-loop structures. Finally, PCGs sequences were used to perform a phylogenetic study. Both maximum likelihood and Bayesian inference analyses highly support Nabidae as the sister group to Anthocoridae and Miridae.

]]> Hu Li, Haiyu Liu, Liangming Cao, Aimin Shi, Hailin Yang, Wanzhi Cai Ivyspring International Publisher 8 1 93 107 2011-11-24 Research Paper http://www.biolsci.org/v08p0079.htm The Putative Metal Coordination Motif in the Endonuclease Domain of Human Parvovirus B19 NS1 Is Critical for NS1 Induced S Phase Arrest and DNA Damage http://www.biolsci.org/v08p0079.htm The non-structural proteins (NS) of the parvovirus family are highly conserved multi-functional molecules that have been extensively characterized and shown to be integral to viral replication. Along with NTP-dependent helicase activity, these proteins carry within their sequences domains that allow them to bind DNA and act as nucleases in order to resolve the concatameric intermediates developed during viral replication. The parvovirus B19 NS1 protein contains sequence domains highly similar to those previously implicated in the above-described functions of NS proteins from adeno-associated virus (AAV), minute virus of mice (MVM) and other non-human parvoviruses. Previous studies have shown that transient transfection of B19 NS1 into human liver carcinoma (HepG2) cells initiates the intrinsic apoptotic cascade, ultimately resulting in cell death. In an effort to elucidate the mechanism of mammalian cell demise in the presence of B19 NS1, we undertook a mutagenesis analysis of the protein's endonuclease domain. Our studies have shown that, unlike wild-type NS1, which induces an accumulation of DNA damage, S phase arrest and apoptosis in HepG2 cells, disruptions in the metal coordination motif of the B19 NS1 protein reduce its ability to induce DNA damage and to trigger S phase arrest and subsequent apoptosis. These studies support our hypothesis that, in the absence of replicating B19 genomes, NS1-induced host cell DNA damage is responsible for apoptotic cell death observed in parvoviral infection of non-permissive mammalian cells.

]]> Violetta Kivovich, Leona Gilbert, Matti Vuento, Stanley J. Naides Ivyspring International Publisher 8 1 79 92 2011-11-24 Research Paper http://www.biolsci.org/v08p0066.htm Proteomic Analysis on Acetate Metabolism in Citrobacter sp. BL-4 http://www.biolsci.org/v08p0066.htm Mass production of glucosamine (GlcN) using microbial cells is a worthy approach to increase added values and keep safety problems in GlcN production process. Prior to set up a microbial cellular platform, this study was to assess acetate metabolism in Citrobacter sp. BL-4 (BL-4) which has produced a polyglucosamine PGB-2. The LC-MS analysis was conducted after protein separation on the 1D-PAGE to accomplish the purpose of this study. 280 proteins were totally identified and 188 proteins were separated as acetate-related proteins in BL-4. Acetate was converted to acetyl-CoA by acetyl-CoA synthetase up-regulated in the acetate medium. The glyoxylate bypass in the acetate medium was up-regulated with over-expression of isocitrate lyases and 2D-PAGE confirmed this differential expression. Using 1H-NMR analysis, the product of isocitrate lyases, succinate, increased about 15 times in the acetate medium. During acetate metabolism proteins involved in the lipid metabolism and hexosamine biosynthesis were over-expressed in the acetate medium, while proteins involved in TCA cycle, pentose phosphate cycle and purine metabolism were down-regulated. Taken together, the results from the proteomic analysis can be applied to improve GlcN production and to develop metabolic engineering in BL-4.

]]> Young-Man Kim, Sung-Eun Lee, Byeoung-Soo Park, Mi-Kyung Son, Young-Mi Jung, Seung-Ok Yang, Hyung-Kyoon Choi, Sung-Ho Hur, Jong Hwa Yum Ivyspring International Publisher 8 1 66 78 2011-11-23 Research Paper http://www.biolsci.org/v08p0059.htm EZH2 Methyltransferase and H3K27 Methylation in Breast Cancer http://www.biolsci.org/v08p0059.htm Histone modifications are thought to control the regulation of genetic programs in normal physiology and cancer. Methylation (mono-, di-, and tri-methylation) on histone H3 lysine (K) 27 induces transcriptional repression, and thereby participates in controlling gene expression patterns. Enhancer of zeste (EZH) 2, a methyltransferase and component of the polycomb repressive complex 2 (PRC2), plays an essential role in the epigenetic maintenance of the H3K27me3 repressive chromatin mark. Abnormal EZH2 expression has been associated with various cancers including breast cancer. Here, we discuss the contribution of EZH2 and the PRC2 complex in controlling the H3K27 methylation status and subsequent consequences on genomic instability and the cell cycle in breast cancer cells. We also discuss distinct molecular mechanisms used by EZH2 to suppress BRCA1 functions.

]]> Kyung Hyun Yoo, Lothar Hennighausen Ivyspring International Publisher 8 1 59 65 2011-11-18 Review http://www.biolsci.org/v08p0049.htm Localization, Expression Change in PRRSV Infection and Association Analysis of the Porcine TAP1 Gene http://www.biolsci.org/v08p0049.htm The transporter associated with antigen processing (TAP) translocates antigenic peptides from the cytosol into the lumen of the endoplasmic reticular and plays a critical role in the major histocompatibility complex (MHC) class I molecule-mediated antigenic presentation pathway. In this study, the porcine TAP1 gene was mapped to the pig chromosome 7 (SSC7) and was closely linked to the marker SSC2B02 (retention fraction=43%, LOD=15.18). Subcellular localization of TAP1 by transient transfection of PK15 cells indicated that the TAP1 protein might be located in the endoplasmic reticulum (ER) in pig kidney epithelial cells (PK-15). Gene expression analysis by semi-quantitative RT-PCR revealed that TAP1 was selectively expressed in some immune and immune-related tissues. Quantitative real-time PCR (qRT-PCR) analysis revealed that this gene was up-regulated after treatments that mimic viral and bacterial infection (polyriboinosinic-polyribocytidylic acid (poly(I:C)) and lipopolysaccharide (LPS), respectively). In addition, elevated TAP1 expression was detected after porcine reproductive and respiratory syndrome virus (PRRSV) infection in porcine white blood cells (WBCs). One single nucleotide polymorphism (SNP) in exon 3 of TAP1 was detected in a Landrace pig population by Bsp143I restriction enzyme digestion. Different genotypes of this SNP had significant associations (P<0.05) with the red blood cell distribution width (RDW) of 1-day-old (1 d) pigs (P=0.0168), the PRRSV antibody level (PRRSV Ab) (P=0.0445) and the absolute lymphocyte count (LYM#) (P=0.024) of 17 d pigs. Our results showed that the TAP1 gene might have important roles in swine immune responses, and these results provide useful information for further functional studies.

]]> Nunu Sun, Dewu Liu, Hongbo Chen, Xiangdong Liu, Fanming Meng, Xianwei Zhang, Huiyong Chen, Shengsong Xie, Xinyun Li, Zhenfang Wu Ivyspring International Publisher 8 1 49 58 2011-11-17 Research Paper http://www.biolsci.org/v08p0039.htm Two Closely Related Human Members of Chitinase-like Family, CHI3L1 and CHI3L2, Activate ERK1/2 in 293 and U373 Cells but Have the Different Influence on Cell Proliferation http://www.biolsci.org/v08p0039.htm The activation of extracellular signal-regulated kinases (ERK1/2) has been associated with specific outcomes. Sustained activation of ERK1/2 by nerve growth factor (NGF) is associated with translocation of ERKs to the nucleus of PC12 cells and precedes their differentiation into sympathetic-like neurons whereas transient activation by epidermal growth factor (EGF) leads to cell proliferation. It was demonstrated that different growth factors initiating the same cellular signaling pathways may lead to the different cell destiny, either to proliferation or to the inhibition of mitogenesis and apoptosis. Thus, further investigation on kinetic differences in activation of certain signal cascades in different cell types by biologically different agents are necessary for understanding the mechanisms as to how cells make a choice between proliferation and differentiation.

It was reported that chitinase 3-like 1 (CHI3L1) protein promotes the growth of human synovial cells as well as skin and fetal lung fibroblasts similarly to insulin-like growth factor 1 (IGF1). Both are involved in mediating the mitogenic response through the signal-regulated kinases ERK1/2. In addition, CHI3L1 which is highly expressed in different tumors including glioblastomas possesses oncogenic properties. As we found earlier, chitinase 3-like 2 (CHI3L2) most closely related to human CHI3L1 also showed increased expression in glial tumors at both the RNA and protein levels and stimulated the activation of the MAPK pathway through phosphorylation of ERK1/2 in 293 and U87 MG cells. The work described here demonstrates the influence of CHI3L2 and CHI3L1 on the duration of MAPK cellular signaling and phosphorylated ERK1/2 translocation to the nucleus. In contrast to the activation of ERK1/2 phosphorylation by CHI3L1 that leads to a proliferative signal (similar to the EGF effect in PC12 cells), activation of ERK1/2 phosphorylation by CHI3L2 (similar to NGF) inhibits cell mitogenesis and proliferation.

]]> Pavlo O. Areshkov, Stanislav S. Avdieiev, Olena V. Balynska, Derek LeRoith, Vadym M. Kavsan Ivyspring International Publisher 8 1 39 48 2011-11-16 Research Paper http://www.biolsci.org/v08p0030.htm Serum Bone Alkaline Phosphatase in Assessing Illness Severity of Infected Neonates in the Neonatal Intensive Care Unit http://www.biolsci.org/v08p0030.htm Background: Infections can influence bone metabolism of neonates, which may lead to changes in some bone metabolism biomarkers. The purpose of this study was to determine whether serum bone alkaline phosphatase (BALP), osteocalcin (OC) and beta carboxy-terminal peptide of type I collagen (CTX), as specific biomarkers of bone metabolism, can be used to assess the severity of neonatal infections.

Methods: Sixty-three neonates in the NICU were enrolled in this study. The neonates were divided into infected group (n=33) and non-infected group (n=30). The scores for neonatal acute physiology-perinatal extension II (SNAPPE-II) were calculated and interleukin-6 (IL-6), procalcitonin (PCT), BALP, OC and CTX were measured among the neonates with or without infections, and among the infected neonates before and after treatment.

Results: The serum BALP levels were lower in the infected group than that in the non-infected group (p<0.01). The serum BALP levels increased markedly in the infected neonates after treatment (p<0.01). The serum BALP levels were also inversely correlated with SNAPPE-II of infected neonates before and after treatment (r=-0.56, p<0.05; r=-0.37, p<0.05, respectively). In infected neonates, the differences between serum BALP levels before and after treatment were inversely correlated with those of IL-6 levels (p<0.05). There were no significant changes in the OC, CTX and PCT levels in the infected or non-infected group before and after treatment.

Conclusion: Our data suggest that serum BALP level might be used as a marker for assessing the severity of illness in infected neonates.

]]> Yaozong Zhang, Chenguang Xue, Tian Zhu, Xiaolan Du, Nan Su, Huabing Qi, Jing Yang, Yuan Shi, Lin Chen Ivyspring International Publisher 8 1 30 38 2011-11-9 Research Paper http://www.biolsci.org/v08p0015.htm Influence of Five Potential Anticancer Drugs on Wnt Pathway and Cell Survival in Human Biliary Tract Cancer Cells http://www.biolsci.org/v08p0015.htm Background: The role of Wnt signalling in carcinogenesis suggests compounds targeting this pathway as potential anti-cancer drugs. Several studies report activation of Wnt signalling in biliary tract cancer (BTC) thus rendering Wnt inhibitory drugs as potential candidates for targeted therapy of this highly chemoresistant disease.

Methods: In this study we analysed five compounds with suggested inhibitory effects on Wnt signalling (DMAT, FH535, myricetin, quercetin, and TBB) for their cytotoxic efficiency, mode of cell death, time- and cell line-dependent characteristics as well as their effects on Wnt pathway activity in nine different BTC cell lines.

Results: Exposure of cancer cells to different concentrations of the compounds results in a clear dose-dependent reduction of viability for all drugs in the order FH535 > DMAT > TBB > myricetin > quercetin. The first three substances show high cytotoxicity in all tested cell lines, cause a direct cytotoxic effect by induction of apoptosis and inhibit pathway-specific signal transduction in a Wnt transcription factor reporter activity assay. Selected target genes such as growth-promoting cyclin D1 and the cell cycle progression inhibitor p27 are down- and up-regulated after treatment, respectively.

Conclusions: Taken together, these data demonstrate that the small molecular weight inhibitors DMAT, F535 and TBB have a considerable cytotoxic and possibly Wnt-specific effect on BTC cell lines in vitro. Further in vivo investigation of these drugs as well as of new Wnt inhibitors may provide a promising approach for targeted therapy of this difficult-to-treat tumour.

]]> Julia WACHTER, Daniel NEUREITER, Beate ALINGER, Martin PICHLER, Julia FUEREDER, Christian OBERDANNER, Pietro Di FAZIO, Matthias OCKER, Frieder BERR, Tobias KIESSLICH Ivyspring International Publisher 8 1 15 29 2011-11-7 Research Paper http://www.biolsci.org/v08p0001.htm Enhanced Antitumor Efficacy of Gemcitabine by Evodiamine on Pancreatic Cancer via Regulating PI3K/Akt Pathway http://www.biolsci.org/v08p0001.htm Evodiamine has therapeutic potential against cancers. This study was designed to investigate whether combination therapy with gemcitabine and evodiamine enhanced antitumor efficacy in pancreatic cancer. In vitro application of the combination therapy triggered significantly higher frequency of pancreatic cancer cells apoptosis, inhibited the activities of PI3K, Akt, PKA, mTOR and PTEN, and decreased the activation of NF-κB and expression of NF-κB-regulated products. In vivo application of the combination therapy induced significant enhancement of tumor cell apoptosis, reductions in tumor volume, and inhibited activation of mTOR and PTEN. In conclusion, evodiamine can augment the therapeutic effect of gemcitabine in pancreatic cancer through direct or indirect negative regulation of the PI3K/Akt pathway.

]]> Wei-Tian Wei, Hui Chen, Zhao-Hong Wang, Zhong-Lin Ni, Hai-Bin Liu, Hong-Fei Tong, Hong-Chun Guo, Dian-Lei Liu, Sheng-Zhang Lin Ivyspring International Publisher 8 1 1 14 2011-11-5 Research Paper