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The antiapoptotic BAG3 protein plays a crucial role in cellular proteostasis and it is involved in several signalling pathways governing cell proliferation and survival. Owing to its multimodular structure, it possesses an extensive interactome including the molecular chaperone HSP70 and other specific cellular partners, which make it an eminent factor in several pathologies, particularly in cancer. Despite its potential as a therapeutic target, very few BAG3 modulators have been disclosed so far. Here we describe the identification of a promising BAG3 modulator able to bind the BAG domain of the protein featuring an imidazopyridine scaffold and obtained through the application of the Groebke–Blackburn–Bienaymé chemical synthesis procedure. The disclosed compound 10 showed a relevant cytotoxic activity, and in line with the biological profile of BAG3 disruption, it induced the activation of caspase 3 and 9. [ABSTRACT FROM AUTHOR]

The antiapoptotic BAG3 protein plays a crucial role in cellular proteostasis and it is involved in several signalling pathways governing cell proliferation and survival. Owing to its multimodular structure, it possesses an extensive interactome including the molecular chaperone HSP70 and other specific cellular partners, which make it an eminent factor in several pathologies, particularly in cancer. Despite its potential as a therapeutic target, very few BAG3 modulators have been disclosed so far. Here we describe the identification of a promising BAG3 modulator able to bind the BAG domain of the protein featuring an imidazopyridine scaffold and obtained through the application of the Groebke–Blackburn–Bienaymé chemical synthesis procedure. The disclosed compound 10 showed a relevant cytotoxic activity, and in line with the biological profile of BAG3 disruption, it induced the activation of caspase 3 and 9.

Neuroinflammation mediated by microglia is an important pathophysiological mechanism in neurodegenerative diseases. However, there is a lack of effective drugs to treat neuroinflammation. N-acetyldopamine dimer (NADD) is a natural compound from the traditional Chinese medicine Isaria cicada. In our previous study, we found that NADD can attenuate DSS-induced ulcerative colitis by suppressing the NF-κB and MAPK pathways. Does NADD inhibit neuroinflammation, and what is the target of NADD? To answer this question, lipopolysaccharide (LPS)-stimulated BV-2 microglia was used as a cell model to investigate the effect of NADD on neuroinflammation. Nitric oxide (NO) detection, reactive oxygen species (ROS) detection and enzyme-linked immunosorbent assay (ELISA) results show that NADD attenuates inflammatory signals and proinflammatory cytokines in LPS-stimulated BV-2 microglia, including NO, ROS, tumor necrosis factor (TNF)-α, interleukin (IL)-1β and interleukin-6 (IL-6). Western blot analysis show that NADD inhibits the protein levels of Toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), ASC and cysteinyl aspartate specific proteinase (Caspase)-1, indicating that NADD may inhibit neuroinflammation through the TLR4/NF-κB and NLRP3/Caspase-1 signaling pathways. In addition, surface plasmon resonance assays and molecular docking demonstrate that NADD binds with TLR4 directly. Our study reveals a new role of NADD in inhibiting the TLR4/NF-κB and NLRP3/Caspase-1 pathways, and shows that TLR4-MD2 is the direct target of NADD, which may provide a potential therapeutic candidate for the treatment of neuroinflammation.

Abstract: Helicobacter pylori encodes a single iron-cofactored superoxide dismutase (SodB), which is regulated by the ferric uptake regulator (Fur). Ferrous ion (Fe2+) is necessary for the activation of SodB. The activity of SodB is an important determinant of the capability of H. pylori for long-term colonization of the stomach and of the development of metronidazole (Mtz) resistance of the bacterium. This study is conducted to characterize the Fe2+-supply mechanisms for the activation of SodB in H. pylori, which, as mentioned above, is associated with the host-colonization ability and Mtz resistance of H. pylori. In this study, we demonstrate that fecA1, a Fe3+-dicitrate transporter homolog, is an essential gene for SodB activation, but not for the biogenic activity of H. pylori. H. pylori with SodB inactivation by fecA1 deletion showed reduced resistance to H2O2, reduced gastric mucosal-colonization ability in Mongolian gerbils, and also reduced resistance to Mtz. Our experiment demonstrated that FecA1 is an important determinant of the host-colonization ability and Mtz resistance of H. pylori through Fe2+ supply to SodB, suggesting that FecA1 may be a possible target for the development of a novel bactericidal drug. [Copyright &y& Elsevier]

Abstract: Phase-solubility studies have been used to evaluate the solubilizing effects of cyclodextrins (CDs) on lipophilic, water-insoluble drugs. However, large amounts of CDs and drugs are required to measure solubility by phase-solubility studies. Thus, more efficient approaches to evaluate the interaction of CDs with drugs are needed. Herein we introduce a method that evaluates the interaction between immobilized β-cyclodextrin and psychotropic drugs by surface plasmon resonance assay with a Biacore® system. Association constants and stoichiometries observed were generally consistent with values calculated by traditional methods, such as phase-solubility and continuous variation methods. Results showed that the analytical method using Biacore® was suitable to evaluate CD–drug interactions. [ABSTRACT FROM AUTHOR]

Abstract: Background: The interaction between apolipoprotein (apo) E and β-amyloid (Aβ) is associated with the development of Alzheimer''s disease (AD); however, the details remain unknown. ApoE in cerebrospinal fluid is extensively sialylated, and sialylation of certain proteins are known to modulate biological function. We investigated the effects of a sialic acid moiety of apoE on the apoE–Aβ interaction. Methods: We prepared normal apoE3 and its mutant (Thr194 → Ala) and analyzed their interactions with Aβ1–42 by using the surface plasmon resonance (SPR) assay. In addition, we performed the SPR assay by using apoE-containing lipoproteins treated with neuraminidase. We also assessed the effect of the mutation on the interaction of apoE3 with liposomes. Results: The binding avidity of the mutant apoE3# was approximately 50% that of normal apoE3 (p <0.0001). The binding avidity of the apoE-containing lipoproteins for Aβ1–42 reduced after neuraminidase treatment. Conclusions: We suggest that AD development is controlled not only by the apoE isoforms but also by the posttranslational modifications in apoE, such as those in the sialic acid moieties, which are abundant in apoE derived from the brain. [Copyright &y& Elsevier]

Abstract: Tumor necrosis factor-α (TNF-α) inducing protein (Tipα) is a carcinogenic factor secreted from Helicobacter pylori (H. pylori), mediated through both enhanced expression of TNF-α and chemokine genes and activation of nuclear factor-κB. Since Tipα enters gastric cancer cells, the Tipα binding molecules in the cells should be investigated. The direct DNA-binding activity of Tipα was observed by pull down assay using single- and double-stranded genomic DNA cellulose. The surface plasmon resonance assay, indicating an association between Tipα and DNA, revealed that the affinity of Tipα for (dGdC)10 is 2400 times stronger than that of del-Tipα, an inactive Tipα. This suggests a strong correlation between DNA-binding activity and carcinogenic activity of Tipα. And the DNA-binding activity of Tipα was first demonstrated with a molecule secreted from H. pylori. [Copyright &y& Elsevier]

Drug systems targeting tumor cells using basic fibroblast growth factor (bFGF) have been widely reported. In this study, the peptide KRTGQYKLC (bFGFp), containing cysteine at the carboxyl termination of the bFGF-derived peptide, was applied as a novel ligand targeting tumor cells. bFGFp was conjugated with bovine serum albumin (BSA) and liposomes. The peptide was shown to inhibit the binding of bFGF to FGF receptor-1 (FGFR1). Interestingly, the binding study using surface plasmon resonance (SPR) assay revealed that the bFGFp-BSA was not bound to FGFR1, but was selectively bound to bFGF. Furthermore, the SPR assay showed that bFGFp-BSA is capable of binding to FGFR1 following the pretreatment with bFGF. The confocal microscopy study indicated that the uptake of bFGFp-BSA by NIH3T3 cells, which highly express FGFRs, was significantly enhanced by pretreatment with bFGF. Then, PEGylated liposomes containing bFGFp (bFGFp-liposome) were prepared by conjugating maleimide-PEG-PE with bFGFp. Following the pretreatment of bFGF, the uptake of bFGFp-liposomes by NIH3T3 cells was significantly enhanced. These results suggest that bFGFp-BSA and bFGFp-liposomes are taken by NIH3T3 cells via binding with bFGF. In addition, both bFGFp-BSA and bFGFp-liposomes had no effect on the proliferation of NIH3T3 cells. This strategy can be used as a novel system for targeting tumors highly expressing FGFRs without a proliferation effect. [ABSTRACT FROM AUTHOR]

β-dystroglycan (β-DG) assembles with lamins A/C and B1 and emerin at the nuclear envelope (NE) to maintain proper nuclear architecture and function. To provide insight into the nuclear function of β-DG, we characterized the interaction between β-DG and emerin at the molecular level. Emerin is a major NE protein that regulates multiple nuclear processes and whose deficiency results in Emery–Dreifuss muscular dystrophy (EDMD). Using truncated variants of β-DG and emerin, via a series of in vitro and in vivo binding experiments and a tailored computational analysis, we determined that the β-DG–emerin interaction is mediated at least in part by their respective transmembrane domains (TM). Using surface plasmon resonance assays we showed that emerin binds to β-DG with high affinity (KD in the nanomolar range). Remarkably, the analysis of cells in which DG was knocked out demonstrated that loss of β-DG resulted in a decreased emerin stability and impairment of emerin-mediated processes. β-DG and emerin are reciprocally required for their optimal targeting within the NE, as shown by immunofluorescence, western blotting and immunoprecipitation assays using emerin variants with mutations in the TM domain and B-lymphocytes of a patient with EDMD. In summary, we demonstrated that β-DG plays a role as an emerin interacting partner modulating its stability and function. [ABSTRACT FROM AUTHOR]