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The effect of dietary substitution of silkworm ( Bombyx mori L) meal ( SM) for fishmeal ( FM) on the growth performance and non-specific immunity of sea cucumber ( Apostichopus japonicus) (initial weight: 12.8 ± 0.16 g) was determined. Four isonitrogenous and isocaloric diets were formulated: Diet 1, which served as the control diet, contained 5% FM; Diet 2 contained 3.75% FM and 1.25% SM; Diet 3 contained 2.5% FM and 2.5% SM; and Diet 4 contained 5% SM. Other ingredients in each of the four diets were kept in the same proportion. After 8 weeks of feeding, the results showed that sea cucumbers fed Diet 2 had 18.7% increases in weight over those fed the control diet, but no significant difference was observed. No obvious difference in body wall composition was detected among the sea cucumbers fed the four different diets. Immunity analysis indicated that phagocytosis and serum alkaline phosphatase activity were not significantly ( P > 0.05) affected when FM was partially or completely replaced with SM. Serum lysozyme activity of sea cucumbers fed Diet 4 showed a significant ( P < 0.05) growth increase compared with those fed control diet. The results revealed that SM could be an effective substitute for FM in sea cucumber diet. [ABSTRACT FROM AUTHOR]

Growing genetic and epidemiological evidence suggests a direct connection between the disruption of circadian rhythm and breast cancer. Moreover, the expression of several molecular components constituting the circadian clock machinery has been found to be modulated by estrogen-estrogen receptor α (E2-ERα) signaling in ERα-positive breast cancer cells. In this study, we investigated the regulation of CLOCK expression by ERα and its roles in cell proliferation. Immunohistochemical analysis of human breast tumor samples revealed high expression of CLOCK in ERα-positive breast tumor samples. Subsequent experiments using ERα-positive human breast cancer cell lines showed that both protein and mRNA levels of CLOCK were up-regulated by E2 and ERα. In these cells, E2 promoted the binding of ERα to the EREs (estrogen-response elements) of CLOCK promoter, thereby up-regulating the transcription of CLOCK. Knockdown of CLOCK attenuated cell proliferation in ERα-positive breast cancer cells. Taken together, these results demonstrated that CLOCK could be an important gene that mediates cell proliferation in breast cancer cells. [ABSTRACT FROM AUTHOR]

Vibrio vulnificus is a causative agent of serious food-borne diseases in humans related to the consumption of raw seafood. It secretes a metalloprotease that is associated with skin lesions and serious hemorrhagic complications. In this study, we purified and characterized an extracellular metalloprotease (designated as vEP) having prothrombin activation and fibrinolytic activities from V. vulnificus ATCC 29307. vEP could cleave various blood clotting-associated proteins such as prothrombin, plasminogen, fibrinogen, and factor Xa, and the cleavage could be stimulated by addition of 1 mM Mn2+ in the reaction. The cleavage of prothrombin produced active thrombin capable of converting fibrinogen to fibrin. The formation of active thrombin appeared to be transient, with further cleavage resulting in a loss of activity. The cleavage of plasminogen, however, did not produce an active plasmin. vEP could cleave all three major chains of fibrinogen without forming a clot. It could cleave fibrin polymer formed by thrombin as well as the cross-linked fibrin formed by factor XIIIa. In addition, vEP could also cleave plasma proteins such as bovine serum albumin and gamma globulin, and its broad specificity is reflected in the cleavage sites, which include Asp207-Phe208 and Thr272- Ala273 bonds in prothrombin and a Tyr80-Leu81 bond in plasminogen. Taken together, the data suggest that vEP is a broad-specificity protease that could function as a prothrombin activator and a fibrinolytic enzyme to interfere with blood homeostasis as part of the mechanism associated with the pathogenicity of V. vulnificus in humans and thereby facilitate the development of systemic infection. [ABSTRACT FROM AUTHOR]

Pyruvate decarboxylase (PDC, EC 4.1.1.1) is a thiamin diphosphate-dependent enzyme about which there is a large body of structural and functional information. The active site contains several absolutely conserved ionizable groups and all of these appear to be important, as judged by the fact that mutation diminishes or abolishes catalytic activity. Previously we have shown [Schenk, G., Leeper, F.J., England, R., Nixon, P.F. & Duggleby, R.G. (1997) Eur. J. Biochem. 248, 63–71] that the activity is pH-dependent due to changes in kcat/Km while kcat itself is unaffected by pH. The effect on kcat/Km is determined by a group with a pKa of 6.45; the identity of this group has not been determined, although H113 is a possible candidate. Here we mutate five crucial residues in the active site with ionizable side-chains (D27, E50, H113, H114 and E473) in turn, to residues that are nonionizable or should have a substantially altered pKa. Each protein was purified and characterized kinetically. Unexpectedly, the pH-dependence of kcat/Km is largely unaffected in all mutants, ruling out the possibility that any of these five residues is responsible for the observed pKa of 6.45. We conjecture that the kcat/Km profile reflects the protonation of an alcoholate anion intermediate of the catalytic cycle. [ABSTRACT FROM AUTHOR]

Examines the mutagenesis of pyruvate decarboxylase (PDC) from Zymomonas mobilis. Identification of acetaldehyde as a normal product of PDC; Ability of the enzyme to produce acetoin as a by-product from the hydroxyethyl-ThDP reaction; Reversibility of acetaldehyde formation in wild-type zymomonas mobilis.

Examines the role of the carboxyl terminus of Zymomonas mobilis pyruvate decarboxylase. Construction of 15 variants of the enzyme with serial deletions; Important roles of the side-chains R561 and the backbone atoms of S560; Importance of the carboxyl-terminal region to lock in the cofactors and proper closure of the active site.

Purpose: Abnormal acetylation modification is a common epigenetic change in tumorigenesis and is closely related to the progression of colorectal cancer (CRC). Our previous studies have suggested that black raspberry (BRB) anthocyanins have a significant chemopreventive effect against CRC. This study investigated whether protein acetylation plays an important role in BRB anthocyanins-mediated regulation of CRC progression. Methods: We used the AOM-induced CRC mouse model and the CRC cell lines SW480 and Caco-2 to explore the potential role of acetylation of histone H4 and NF-κB signaling pathway-related proteins (non-histone proteins) in the antitumor process mediated by BRB anthocyanins. The expression of related proteins was detected by western blot. ROS level was detected by immunofluorescence. Results: BRB anthocyanins affected the acetylation level by down-regulating the expression of Sirtuin1 (SIRT1) and up-regulating the expression of MOF and EP300. The acetylation level of lysine sites on histone H4 (H4K5, H4K12 and H4K16) was increased. Furthermore, following BRB anthocyanins treatment, the expression of ac-p65 was significantly up-regulated and the NF-κB signal pathway was activated, which in turn up-regulated Bax expression and inhibited Bcl-2, cyclin-D1, c-myc and NLRP3 expression to promote CRC cell cycle arrest, apoptosis and relieve inflammation. Conclusion: The findings suggested that protein acetylation could play a critical role in BRB anthocyanins-regulated CRC development. [ABSTRACT FROM AUTHOR]

Vibrio vulnificus, a marine bacterium capable of causing wound infection and septicemia, secretes a 45-kDa metalloprotease (vEP) with many biological activities. The precursor of vEP consists of four regions: a signal peptide, an N-terminal propeptide (nPP), a C-terminal propeptide, and the mature protease. Two forms of vEP--vEP-45, which contains the mature protease plus the C-terminal propeptide, and vEP-34, which contains only the mature protease--were expressed in Escherichia coli and purified. vEP-45 and vEP-34 had similar activities with azocasein as a substrate, but vEP-34 had reduced activity toward insoluble proteins. The nPP of vEP was expressed as a His tag fusion protein, and its effect on vEP activity was investigated. nPP inhibited the activities of both vEP-45 and vEP-34 but not that of thermolysin, a different but related zinc-dependent protease. The inhibition of vEP by nPP was further examined using vEP-34 as a representative enzyme. The inhibition could be completely reversed under conditions of low enzyme and propeptide concentrations and with prolonged incubation, which resulted from the degradation of nPP by vEP. However, even at high nPP and vEP concentrations, inhibition of vEP by nPP at high temperatures was not effective, resulting in the degradation of both nPP and vEP. These results demonstrate that the nPP of vEP could bind to vEP and inhibit its activity, resulting in the degradation of the propeptide. [ABSTRACT FROM AUTHOR]

The process of wound healing involves a complex and vast interplay of growth factors and cytokines that coordinate the recruitment and interaction of various cell types. A series of events involving inflammation, proliferation, and remodeling eventually leads to the restoration of the damaged tissue. Abrogation in the regulation of these events has been shown to result in excessive scarring or non-healing wounds. While the process of wound healing is not fully elucidated, it has been documented that the early events of wound healing play a key role in the outcome of the wound. Furthermore, high levels of inflammation have been shown to lead to scarring. The regulation of these events may result in scarless wound healing, especially in adults. The inhibition of transforming growth factor-β (TGF-β) and the administration of keratinocyte growth factors (KGF), KGF-1 and KGF-2, has in recent years yielded positive results in the acceleration of wound closure and reduced scarring. Here, we encapsulate recent knowledge on the roles of TGF-β, KGF1, and KGF2 in wound healing and scar formation and highlight the areas that need further investigation. We also discuss potential future directions for the use of growth factors in wound management. [Display omitted] The nature and characteristics of the scar are determined by events at the wound site. These events are regulated and driven by effector molecules of the growth factor signaling. • Wound healing is a complex process involving multiple molecules that regulate and determine its outcome. • Growth factors can facilitate wound closure and improve dermal architecture following healing. • The JAK/STAT signaling influences scar outcome by exacerbating inflammation and upregulating collagen. • Advanced drug delivery systems are critical for effective growth factor treatment and scarless healing. [ABSTRACT FROM AUTHOR]

Aryl hydrocarbon receptor (AhR) is a transcription factor that belongs to the basic helix-loop-helix (bHLH) Per-Arnt-Sim homology domain (PAS) family. AhR can be activated by 2, 3, 7, 8-tetrachlorodibenzo- p-dioxin (2, 3, 7, 8-TCDD) and once activated, it promotes the abnormal expression of cytochrome P450, leading to several diseases, including cancer. In this study, we showed that AhR is subjected to post-translational modification by SUMOylation and this modification could be reversed by SENP1. Two SUMOylation sites were identified, one in the bHLH domain (K63) and the other in the TAD domain (K510) of AhR. Substitution of either K63 or K510 with arginine resulted in reduced SUMOylation for AhR. Treatment of MCF-7 cells with TCDD led to a reduced level of SUMOylated AhR in a time-dependent manner, and this occurred mainly in the nucleus. SUMOylation of AhR enhanced its stability through inhibiting its ubiquitination. Moreover, SUMOylation also repressed the transactivation activity of AhR and this could be reversed by TCDD. These results suggested that SUMOylation of AhR might play an important role in the regulation of its function, and TCDD may activate the transcriptional activity of AhR through downregulating its SUMOylation. J. Cell. Physiol. 227: 3812-3819, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Yeast flocculation is an important trait in the brewing industry as well as in ethanol production, through which biomass can be recovered by cost-effective sedimentation. However, mass transfer limitation may affect yeast growth and ethanol fermentation if the flocculation occurs earlier before fermentation is completed. In this article, a novel type of cell-cell flocculation induced by trehalose-6-phosphate synthase 1 (TPS1) promoter was presented. The linear cassette HO–P TPS1–FLO1 SPSC01–KanMX4–HO was constructed to transform the non-flocculating industrial yeast S. cerevisiae 4126 by chromosome integration to obtain a new flocculating yeast strain, ZLH01, whose flocculation was induced by ethanol produced during fermentation. The experimental results illustrated that flocculation of ZLH01 was triggered by 3% (v/v) ethanol and enhanced as ethanol concentration increased till complete flocculation was achieved at ethanol concentration of 8% (v/v). Real time PCR analysis confirmed that the expression of FLO1 SPSC01 was dependent on ethanol concentration. The growth and ethanol fermentation of ZLH01 were improved significantly, compared with the constitutive flocculating yeast BHL01 engineered with the same FLO gene but directed by the constitutive 3-phosphoglycerate kinase promoter PGK1, particularly under high temperature conditions. These characteristics make the engineered yeast more suitable for ethanol production from industrial substrates under high gravity and temperature conditions. In addition, this strategy offers advantage in inducing differential expression of other genes for metabolic engineering applications of S. cerevisiae. [Copyright &y& Elsevier]

Abstract: Mitochondrial proteins of Plasmodium falciparum are considered as attractive targets for anti-malarial drugs, but the experimental identification of these proteins is a difficult and time-consuming task. Computational prediction of mitochondrial proteins offers an alternative approach. However, the commonly used subcellular location prediction methods are unsuited for P. falciparum mitochondrial proteins whereas the organism and organelle-specific methods were constructed on the basis of a rather small dataset. In this study, a novel dataset termed PfM233, which included 108 mitochondrial and 125 non-mitochondrial proteins with sequence similarity below 25%, was established and the methods for predicting mitochondrial proteins of P. falciparum were described. Both bi-profile Bayes and split amino acid composition were applied to extract the features from the N- and C-terminal sequences of these proteins, which were then used to construct two SVM based classifiers (PfMP-N25 and PfMP-30). Using PfM233 as the dataset, PfMP-N25 and PfMP-30 achieved accuracies (MCCs) of 90.13% (0.80) and 90.99% (0.82). When tested with the commonly used 40 mitochondrial proteins in PfM175 and the 108 mitochondrial proteins in PfM233, these two methods obviously outperformed the existing general, organelle-specific and organism and organelle-specific methods. [Copyright &y& Elsevier]

Abstract: Gram-negative bacteria-binding proteins (GNBPs) are important pattern recognition receptors (PRRs) in invertebrate innate immune systems. These immune proteins are capable of identifying and binding to specific targets on the surface of microorganisms, and thereby trigger a variety of defense reactions through the activation of protease cascades and intracellular immune signaling pathways. In this paper, a full-length cDNA of GNBP coding for a conserved β-glucan-binding domain was isolated from Artemia sinica. Bioinformatic analysis showed that it belonged to a new member of the GNBP family. The expression of GNBP was investigated at various stages during the embryonic development of A. sinica using real-time PCR and immunohistochemistry assay. The result showed that the highest expression level was on the 10th day of the embryo. The larvae showed a remarkable down-regulation of GNBP transcript after challenged with Gram-negative bacteria. In contrast, the level of GNBP transcript in the larvae increased gradually after challenged with Gram-positive bacteria. Immunohistochemistry assay showed that during embryonic development, GNBP protein was mainly expressed in the head, thorax, and on the alimentary canal surface. This new GNBP member showed a constitutive and regional expression during the early embryonic development of A. sinica, and may therefore play an important role at the adult stage, as well as during infection. [ABSTRACT FROM AUTHOR]

BACKGROUND: Increasing evidence has established neuroinflammation as the hallmark of neurodegenerative disorders such as Alzheimer's disease (AD). However, despite the underlying immunological mechanisms are far from being understood, the involvement of excessive activation of microglia is attracting more and more attention. OBJECTIVE: In the present study, we investigated the protective effect of black raspberry (BRB) anthocyanins on LPS-induced neuroinflammation in BV2 microglia. METHODS: LPS-induced mouse BV2 microglia were treated with black raspberry anthocyanins and the levels of NO, ROS, IL-1β and IL-18 produced by the cells were measured to determine the extent of oxidative stress and inflammatory response. RESULTS: The results showed that BRB anthocyanins reduced the production of ROS in LPS-induced BV2 microglia by down-regulating the level of NOX2 and its downstream factors, including thioredoxin-interacting protein (TXNIP) and NOD-like receptor protein 3 (NLRP3) inflammasome. Furthermore, BRB anthocyanins inhibited the secretion of Interleukin-18 (IL-18) and Interleukin-1β (IL-1β), eventually attenuating the LPS-induced inflammatory response of BV2 microglia. CONCLUSIONS: BRB anthocyanins might play an important neuroprotective role in inflammation-related neurodegenerative disease, potentially, by down-regulating the NOX2 /TXNIP/ NLRP3 signaling axis in brain microglia. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mangosteen is a good source of xanthones with antidiabetic effect. • Six xanthones with PTP1B inhibitory activity were identified in mangosteen extract. • Garcinone E was the most effective PTP1B inhibitor (IC50 of 0.43 μM). • Mangosteen might exert its antidiabetic effect via its PTP1B-inhibiting xanthones. • The distribution of xanthones in eleven tissues has certain differences. Garcinia mangostana L. (mangosteen) is a tropical fruit that is rich in xanthones and is thought to have an anti-diabetic effect. In this study, we screened for the xanthones in mangosteen that could inhibit the activity of protein tyrosine phosphatase 1B (PTP1B), an enzyme that is targeted by diabetic drugs. Mice were orally administered mangosteen extract and blood samples were screened for the presence of PTP1B-interacting xanthones. Six such compounds (1 – 6) were identified by UF-HPLC-QTOF-MS and their inhibition against PTP1B was confirmed by activity assay. Among them, garcinone E (5) was found to be the most effective PTP1B inhibitor (IC 50 = 0.43 μM). Tissue distribution analysis showed that the six compounds were distributed in eleven tissues, including the liver, muscle, fat, stomach, large intestine, small intestine, brain, kidney, heart, lung, and spleen. The results demonstrated that mangosteen might be a promising source of natural compounds with high PTP1B-inhibitory activity. [ABSTRACT FROM AUTHOR]

Protein disulfide isomerase (PDI) is an important molecular chaperone capable of facilitating protein folding in addition to catalyzing the formation of a disulfide bond. To better understand the distinct substrate-screening principles of Pichia pastoris PDI (Protein disulfide isomerase) and the protective role of PDI in amyloidogenic diseases, we investigated the expression abundance and intracellular retention levels of three archetypal amyloidogenic disulfide bond-free proteins (Aβ42, α-synuclein (α-Syn) and SAA1) in P. pastoris GS115 strain without and with the overexpression of PpPDI (P. pastoris PDI). Intriguingly, amyloidogenic Aβ42 and α-Syn were detected only as intracellular proteins whereas amyloidogenic SAA1 was detected both as intracellular and extracellular proteins when these proteins were expressed in the PpPDI-overexpressing GS115 strain. The binding between PpPDI and each of the three amyloidogenic proteins was investigated by molecular docking and simulations. Three different patterns of PpPDI-substrate complexes were observed, suggesting that multiple modes of binding might exist for the binding between PpPDI and its amyloidogenic protein substrates, and this could represent different specificities and affinities of PpPDI toward its substrates. Further analysis of the proteomics data and functional annotations indicated that PpPDI could eliminate the need for misfolded proteins to be partitioned in ER-associated compartments. [ABSTRACT FROM AUTHOR]

This communication describes the inhibitory effect of Morin on the fibrillation of Hen Egg White Lysozyme (HEWL), a generic amyloid-forming model protein. This effect was dose-dependent and stronger than other small molecules we have tested previously. Spectrofluorometric and computational studies support a model suggesting that Morin inhibits amyloid fibril formation of HEWL by binding to the aggregation prone cleft region of the β-domain of HEWL, thereby stabilizing the molecule in its native-like state. Interestingly, transmission electron microscopy observations suggest that, along with increases in Morin concentration, the observed amorphous aggregates became larger and morphologically different. We propose that following occupation of the binding cleft, excess Morin adheres and coats the HEWL protein surface, thereby minimizing the interaction between the protein surface and water molecules. [ABSTRACT FROM AUTHOR]

Background: The success of cuckoo parasitism is thought to depend largely on the extent of egg matching between cuckoo and host eggs, since poor-matching cuckoo egg would lead to more frequent egg rejection by the host. In this study, we investigated how egg-spot matching between the Common Cuckoo (Cuculus canorus) and its host, the Oriental Reed Warbler (Acrocephalus orientalis) is affected by the local parasitism rate, nest availability in breeding synchronization and egg rejection. Methods: We used the paired design of parasitized and their nearest non-parasitized nests where breeding occurred simultaneously to compare egg-spot matching. The image analysis was used to compare four eggshell pattern variables, namely spot size, density, coverage on the different areas of egg surface, and the distribution on the whole egg surface. Egg recognition experiments were conducted to test the effect of egg spots on egg rejection by the host. Results: Our results show that much better matching in almost all spot parameters tested on the side of the egg and the spot distribution on the whole egg occurred in parasitized nests than in non-parasitized nests. Matching of spot density between cuckoo and host eggs in parasitized nests increased with the synchronization between temporal availability of nests and the egg-laying period of female cuckoos. Egg recognition experiments in which the warbler eggs were deliberately painted with extra spots led to a significantly higher egg rejection rate (78.3%) than of unpainted eggs. Conclusion: Our data suggest that both the high temporal encounter rate between cuckoo and warbler nests as well as the high egg rejection ability of the host are important factors for egg-spot matching of the cuckoos. [ABSTRACT FROM AUTHOR]

3β-Hydroxysteroid-Δ24 reductase (DHCR24) is an endoplasmic reticulum (ER)-localized multifunctional enzyme that possesses anti-apoptotic and cholesterol-synthesizing activities. Accumulating evidence suggests that ER stress is involved in the pathogenesis of neurodegenerative disease. In this study, we investigated whether DHCR24 may function as a neuroprotective protein under ER stress. Neuroblastoma N2A cells were infected with adenovirus expressing myc-tagged DHCR24 (Ad-DHCR24) or lacZ (Ad-lacZ, serving as a control) and subjected to ER-stress, induced with Tunicamycin (TM). Cells infected with Ad-DHCR24-myc were resistant to TM-induced apoptosis, and showed weaker level of caspase-12 activity. These cells also exhibited lower levels of Bip and CHOP proteins than Ad-LacZ-infected cells. Moreover, a stronger and rapid activation of PERK, and a prolonged activation of JNK and p38 were observed in Ad-LacZ–infected cells. The generation of intracellular reactive oxygen species from ER stress was also diminished by the overexpression of DHCR24. Additionally, intracellular cholesterol level was also elevated in the Ad-DHCR24-infected cells, accompanied by a well-organized formation of caveolae (cholesterol-rich microdomain) on the plasma membrane, and improved colocalization of caveolin-1 and insulin-like growth factor 1 receptor. These results demonstrated for the first time that DHCR24 could protect neuronal cells from apoptosis induced by ER stress. [ABSTRACT FROM AUTHOR]

Epithelial Mesenchymal Transition (EMT) plays a major role in cancer metastasis. Several genes have been shown to play a role in EMT, and one of these is Amplified-in-breast cancer 1 (AIB1), which has oncogenic function and is known to be amplified in breast cancer. However, the role of AIB1 in EMT remains largely undefined at the molecular level. In this study, the effect of AIB1 overexpression on the EMT of the breast cancer cell line T47D was investigated. Overexpression of AIB1 disrupted the epithelial morphology of the cells. At the same time, the cells displayed a strong metastasis and reduced level of the epithelial marker E-cadherin. In contrast, knockdown of AIB1 in T47D cells increased cell-cell adhesion and produced weak metastasis, as well as a higher level of E-cadherin expression. We proposed that the regulation of EMT by AIB1 occurred through the action of the transcription factor SNAI1, and demonstrated that such interaction required the participation of ERα and the presence of ERα-binding site on SNAI1 promoter. The expression level of E-cadherin and the extent of cell migration and invasion in SNAI1-knocked down T47D cells that overexpressed AIB1 were similar to those of T47D cells that did not overexpress AIB1 and had no SNAI1 knockdown. Taken together, these results suggested that AIB1 exerted its effect on EMT through its interaction with ERα, which could directly bind to the ERα-binding site on the SNAI1 promoter, allowing the AIB1-ERα complex to promote the transcription of SNAI1 and eventually led to repression of E-cadherin expression, consistent with the loss of E-cadherin being a hallmark of EMT. [ABSTRACT FROM AUTHOR]

Background: Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a phosphatase having both protein and lipid phosphatase activities, and is known to antagonize the phosphoinositide 3-kinase/AKT (PI3K/ AKT) signaling pathway, resulting in tumor suppression. PTEN is also known to play a role in the regulation of numerous transcription factors. Amplified in breast cancer 1 (AIB1) is a transcriptional coactivator that mediates the transcriptional activities of nuclear receptors and other transcription factors. The present study investigated how PTEN may regulate AIB1, which is amplified and/or overexpressed in many human carcinomas, including breast cancers. Results: PTEN interacted with AIB1 via its phophatase domain and regulated the transcriptional activity of AIB1 by enhancing the ubiquitin-mediated degradation of AIB1. This process did not appear to require the phosphatase activity of PTEN, but instead, involved the interaction between PTEN and F-box and WD repeat domain-containing 7 alpha (Fbw7a), the E3 ubiquitin ligase involved in the ubiquitination of AIB1. PTEN interacted with Fbw7a via its C2 domain, thereby acting as a bridge between AIB1 and Fbw7a, and this led to enhanced degradation of AIB1, which eventually accounted for its decreased transcriptional activity. At the cell level, knockdown of PTEN in MCF-7 cells promoted cell proliferation. However when AIB1 was also knocked down, knockdown of PTEN had no effect on cell proliferation. Conclusions: PTEN might act as a negative regulator of AIB1 whereby the association of PTEN with both AIB1 and Fbw7a could lead to the downregulation of AIB1 transcriptional activity, with the consequence of regulating the oncogenic function of AIB1. [ABSTRACT FROM AUTHOR]

Background information Amplified in breast cancer 1 (AIB1) is a transcriptional coactivator of nuclear receptors and other transcription factors. It is required for animal growth and reproductive development, and has also been implicated in breast carcinogenesis. Although AIB1 is known to be covalently modified by SUMO-1, which serves to regulate its stability and transcriptional activity, the exact SUMO E3 ligase involved in its sumoylation has not been determined. In order to resolve this question, we investigated the interaction between AIB1 and different members of PIAS proteins (all are SUMO E3 ligases) through immunoprecipiation. Results Among the five different PIAS proteins, only PIAS1 co-immunoprecipitated with AIB1 in extract prepared from breast cancer cells (MCF-7). Over-expression of PIAS1 together with AIB1 in MCF-7 cells led to increased sumoylation of AIB1, resulting in repression of its transcriptional activity. In contrast, the PIAS1 mutant (C350S) lacking E3 ligase activity appeared to have no effect on the sumoylation of AIB1. Through sumoylation of AIB1, PIAS1 also promoted the stability of AIB1 and attenuated its interaction with estrogen receptor α (ERα), resulting in repression of the transactivation activity of ERα. In addition, MCF-7 cells co-transfected with wild-type PIAS1 and AIB1 showed about 40% reduction in cell growth, while cells co-transfected with wild-type PIAS1 and mutant AIB1 resistant to sumoylation showed about 34% increase in cell growth compared to cells transformed with wild-type AIB1 only. Conclusions Taken together, these results suggested that PIAS1 may play a crucial role in the regulation of AIB1 transcriptional activity through sumoylation. [ABSTRACT FROM AUTHOR]

[Display omitted] • NSAID selenocyanate derivatives were found to exhibit a neuroprotective effect. • 1-39 and 1A-38 could significantly suppress NOX2 expression and ROS production. • There appeared to be a link between the NLRP3 signaling pathway and the neuroprotective effect of 1-39 and 1A-38. • NSAID selenocyanate derivatives might be considered as potential therapeutic agents of neurodegenerative diseases. Neuro-inflammation is an immune response of the central nervous system (CNS) to pathogens, and it is associated with a variety of neurodegenerative diseases. Microglial cells are the main category of macrophages in the CNS parenchyma, and they represent one of the most important cellular drivers and regulators of neuroinflammation. In this study, nine new organoselenium compounds based on the hybridization of nonsteroidal anti-inflammatory drugs (NSAIDs) skeleton and organoselenium motif (-SeCN and -SeCF3) were synthesized and their potential anti-neuroinflammatory effects were evaluated using LPS-induced BV2 mouse microglia. The cells were first treated with the organoselenium compounds and the extent of oxidative stress and inflammatory response of the cells was determined by measuring the levels of NO, ROS, IL-1β, and IL-18. Among the nine compounds, 1-39 and 1A-38 exhibited the most significant effect on oxidative stress and inflammatory response. Subsequent studies carried out with 1-39 and 1A-38 showed that both compounds could reduce the production of ROS in the cells, probably through down-regulating NOX2 and its downstream targets, including TXNIP (thioredoxin-interacting protein) and NLRP3 (NOD-like receptor protein 3). In addition, 1-39 and 1A-38 also suppressed the ability of the cells to secret IL-18 and IL-1β, which greatly dampened the response of the cells to LPS-induced inflammation. Our finding demonstrated that organoselenium compounds derived from NSAID might play an important role in the protection of brain microglia against inflammation-related neurodegenerative disease by potentially down-regulating the NOX2/NLRP3 signaling axis. [ABSTRACT FROM AUTHOR]

Clam farming comprises an important part of China's economy. However, increasing pollution in the ocean caused by toxic metals has led to the bioaccumulation of toxic metals in marine animals, especially the bivalves such as clams, and the consequence of heavy metal-associated toxicity in these animals. Such toxicity can enhance the production of reactive oxygen species (ROS) within the tissues of the animals. In aquatic species, oxidative stress mechanisms have been studied by measuring the antioxidant and oxidative damage index in the tissues. The objectives of this study were to investigate the levels of different toxic metals and the extent of oxidative stress responses in the clam Sinonovacula constricta at different growth periods (from May to October) in an aquaculture farm in Wengyang, an important economic shellfish culture zone in Zhejiang Province, China. Water and sediment samples taken from the farm were subjected to Pb, Hg, Cd, Cr assays. Overall, the levels of these metals in the water and sediment could be considered as light pollution, though the levels of Hg in the water (0.266) and Cd in the sediment (0.813) could be considered as reaching moderate pollution. In addition, the levels of these metals, H 2 O 2 , MDA and GSH content, antioxidant enzyme (CAT, SOD, GPx) activities as well as the level of metallothioneins (MT) mRNA in the tissues of S. constricta were also analyzed. The levels of Pb, Hg, Cd, Cr increased with increasing culturing time, and a higher level of these metals was accumulated in the visceral mass than in the foot. The levels of MDA and GSH, as well as the level of SOD activity in the viscera and foot of S. constricta increased with increasing metal accumulation. However, CAT and GPX activities, H 2 O 2 level and the expression of MT initially increased and then decreased. This suggested that S. constricta might have the ability to control oxidative damage by triggering antioxidant defense in coordination with the metal sequestering response. The results also implied that toxic metal pollution should be taken into account when selecting the site to be used as an aquaculture farm. In addition, the visceral mass should be considered to be a good tissue for measuring the level of metal pollutants. • Pb, Hg, Cd and Cr levels in Wenyang aquafarm could be considered as light pollution. • Toxic metal pollution should be monitored in bivalve-culture aquafarms. • The visceral mass of Sinonovacula constricta should not be eaten as food. • MDA might be a biochemical marker for a Hg-contaminated aquatic environment. • MT and SOD may play a role in the response of S. constricta to toxic metal pollution. [ABSTRACT FROM AUTHOR]