I-κBα depletion by transglutaminase 2 and μ-calpain occurs in parallel with the ubiquitin-proteasome pathway

Transglutaminase 2 (TGase2) is a calcium-dependent, cross-linking enzyme that catalyzes iso-peptide bond formation between peptide-bound lysine and glutamine residues. TGase 2 can activate NF-κB through the polymerization-mediated depletion of I-κBα without IKK activation. This NF-κB activation mechanism is associated with drug resistance in cancer cells. However, the polymers cannot be detected in cells, while TGase 2 over-expression depletes free I-κBα, which raises the question of how the polymerized I-κBα can be metabolized in cells. Among proteasome, lysosome and calpain systems, calpain inhibition was found to effectively increase the accumulation of I-κBα polymers in MCF7 cells transfected with TGase 2, and induced high levels of I-κBα polymers as well in MDA-MB-231 breast cancer cells that naturally express a high level of TGase 2. Inhibition of calpain also boosted the level of I-κBα polymers in HEK-293 cells in case of TGase 2 transfection either with I-κBα or I-κBα mutant (S32A, S36A). Interestingly, the combined inhibition of calpain and the proteasome resulted in an increased accumulation of both I-κBα polymers and I-κBα, concurrent with an inhibition of NF-κB activity in MDA-MB-231 cells. This suggests that μ-calpain proteasome-dependent I-κBα polymer degradation may contribute to cancer progression through constitutive NF-κB activation.     

THE UTILITY OF PROTEOMICS IN ALGAL TAXONOMY: BOSTRYCHIA RADICANS/B. MORITZIANA (RHODOMELACEAE,RHODOPHYTA) AS A MODEL STUDY1

A comparison of the proteome of eight genetically well‐characterized isolates of the Bostrychia radicans (Mont.) Mont./B. moritziana (Sond. ex Kütz.) J. Agardh species complex was undertaken to establish if genetic relationships among them can be determined using proteome data. Genetic distances were calculated on the basis of common and distinct spots in two‐dimensional gel electrophoresis (2‐DE). Proteomes of the male and female plants of each population were compared to analyze the range of genetic difference within an isolate. Haploid male and female plants of the same species had 3.7%–7.1% sex‐specific proteins. The degree of similarity of the proteome was consistent with previous DNA sequence data and sexual compatibility studies between the isolates. Two sexually compatible isolates from Venezuela showed a pair‐wise distance ranging from 0.14 to 0.21. The isolates from Mexico and Venezuela, which were partially compatible, showed a maximum pair‐wise distance of 0.26. A high level of genetic difference was found among isolates that were sexually incompatible. The isolate from Brazil was reproductively isolated from the Mexico and Venezuela isolates and showed a maximum pair‐wise distance of 0.65 and 0.58, respectively. Comparative proteomics may be helpful for studying genetic distances among algal samples, if intraisolate variation (gene expression) can be minimized or tested.     

CGS 10746B: an atypical antipsychotic candidate that selectively decreases dopamine release at behaviorally effective doses

CGS 10746B, a benzothiadiazepine, has a behavioral profile in mice and monkeys similar to the atypical antipsychotic clozapine. Unlike clozapine, CGS 10746B suppresses dopamine neuron firing rates and, when administered at behaviorally effective doses by the oral or intraperitoneal route, decreases neostriatal dopamine release without changing dopamine metabolism or occupying D2 receptors. CGS 10746B is the first atypical antipsychotic candidate that selectively decreases dopamine release.     

Combination stem cell therapy using dental pulp stem cells and human umbilical vein endothelial cells for critical hindlimb ischemia

Narrowing of arteries supplying blood to the limbs provokes critical hindlimb ischemia (CLI). Although CLI results in irreversible sequelae, such as amputation, few therapeutic options induce the formation of new functional blood vessels. Based on the proangiogenic potentials of stem cells, in this study, it was examined whether a combination of dental pulp stem cells (DPSCs) and human umbilical vein endothelial cells (HUVECs) could result in enhanced therapeutic effects of stem cells for CLI compared with those of DPSCs or HUVECs alone. The DPSCs+ HUVECs combination therapy resulted in significantly higher blood flow and lower ischemia damage than DPSCs or HUVECs alone. The improved therapeutic effects in the DPSCs+ HUVECs group were accompanied by a significantly higher number of microvessels in the ischemic tissue than in the other groups. In vitro proliferation and tube formation assay showed that VEGF in the conditioned media of DPSCs induced proliferation and vessel-like tube formation of HUVECs. Altogether, our results demonstrated that the combination of DPSCs and HUVECs had significantly better therapeutic effects on CLI via VEGF-mediated crosstalk. This combinational strategy could be used to develop novel clinical protocols for CLI proangiogenic regenerative treatments.     

Cloning, expression, and characterization of a cDNA encoding snake venom metalloprotease

A cDNA clone, MT-c, encoding metalloprotease was isolated from snake (Agkistrodon halys brevicadus) venom gland cDNA library. Deduced amino acid sequence indicated that MT-c is composed of a signal sequence, amino-terminal propeptide, a central metalloprotease domain, and a Lys-Gly-Asp (KGD) disintegrin domain. The partial cDNA encoding metalloprotease and disintegrin domain was subcloned and expressed in E. coli. The expressed MT-c protein was purified and successfully refolded into functional form retaining the enzyme activity. Analyses of the purified recombinant protease activity revealed that the enzyme hydrolyzes extracellular matrix proteins including type I gelatin, type IV and type V collagen, while type I, II, III collagens and fibronectin were insensitive to the proteolytic digestion. The recombinant enzyme was also able to degrade fibrinogen by specifically cleaving A alpha chain of the protein.     

Detection of gene mutations related with drug resistance in Mycobacterium leprae from leprosy patients using Touch-Down (TD) PCR

The lack of methods to identify Mycobacterium leprae with the resistance against multi-drugs quickly and specifically has hindered effective chemotherapy against M. leprae infection. To screen M. leprae with resistance against multi-drugs, the Touch-Down (TD)-PCR has been used in this study. Sequences of the folP, rpoA, B, and gyrA, B genes were analyzed for isolates of M. leprae from leprosy patients in Korea. We amplified designated region of several genes in M. leprae involved in drug resistance and could obtain the PCR products of each gene. The mutations in the particular region of folP, rpoB, and gyrB gene were certified by TD-PCR single-stranded conformational polymorphism and DNA sequencing, respectively.     

A novel pathway responsible for lipopolysaccharide-induced translational regulation of TNF-α and IL-6 expression involves protein kinase C and fascin

Fascin, as a substrate of protein kinase C (PKC), is a well-known cytoskeletal regulatory protein required for cell migration, invasion, and adhesion in normal and cancer cells. In an effort to identify the role of fascin in PKC-mediated cellular signaling, its expression was suppressed by stable transfection of specific short hairpin RNAs (shRNAs) in mouse monocytic leukemia RAW264.7 cells. Suppression of fascin expression resulted in impaired cellular migration and invasion through extracellular matrix proteins. Unexpectedly, the specific shRNA transfectants exhibited a marked reduction in LPS-induced expression of TNF-α and IL-6 by blocking the translation of their mRNAs. Transient transfection assay using a luciferase expression construct containing the 3' untranslated region of TNF-α or IL-6 mRNA revealed a significant reduction in both LPS- and PMA- (the direct activator of PKC) induced reporter activity in cells transfected with fascin-specific shRNA, indicating that fascin-mediated translational regulation targeted 3' untranslated region. Furthermore, LPS-induced translational activation of reporter expression was blocked by a pharmacological inhibitor of PKC, and the dominant-negative form of PKCα attenuated LPS-induced translational activation. The same type of regulation was also observed in the human monocytic leukemia cell line THP-1 and in mouse peritoneal macrophages. These data demonstrate the involvement of fascin in the PKC-mediated translational regulation of TNF-α and IL-6 expression during the LPS response.     

Modulation of immunogenicity of poly(sarcosine) displayed on various nanoparticle surfaces due to different physical properties

Poly(sarcosine) displayed on polymeric micelle is reported to trigger a T cell‐independent type2 reaction with B1a cells in the mice to produce IgM and IgG3 antibodies. In addition to polymeric micelle, three kinds of vesicles displaying poly(sarcosine) on surface were prepared here to evaluate the amounts and avidities of IgM and IgG3, which were produced in mice, to correlate them with physical properties of the molecular assemblies. The largest amount of IgM was produced after twice administrations of a polymeric micelle of 35 nm diameter ( G1 ). On the other hand, the production amount of IgG3 became the largest after twice administrations of G3 (vesicle of 229 nm diameter) or G4 (vesicle of 85 nm diameter). The augmented avidity of IgG3 after the twice administrations compared with that at the single administration was the highest with G3 . These differences in immune responses are discussed in terms of surface density of poly(sarcosine) chains, nanoparticle size, hydrophobic component of poly(L‐lactic acid) or (Leu‐ or Val‐Aib)_n, and membrane elasticity of the nanoparticles. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.     

Host diversity and behavior determine patterns of interspecies transmission and geographic diffusion of avian influenza A subtypes among North American wild reservoir species

Wild birds can carry avian influenza viruses (AIV), including those with pandemic or panzootic potential, long distances. Even though AIV has a broad host range, few studies account for host diversity when estimating AIV spread. We analyzed AIV genomic sequences from North American wild birds, including 303 newly sequenced isolates, to estimate interspecies and geographic viral transition patterns among multiple co-circulating subtypes. Our results show high transition rates within Anseriformes and Charadriiformes, but limited transitions between these orders. Patterns of transition between species were positively associated with breeding habitat range overlap, and negatively associated with host genetic distance. Distance between regions (negative correlation) and summer temperature at origin (positive correlation) were strong predictors of transition between locations. Taken together, this study demonstrates that host diversity and ecology can determine evolutionary processes that underlie AIV natural history and spread. Understanding these processes can provide important insights for effective control of AIV.