The suppressive effects of Bursopentine (BP5) on oxidative stress and NF-ĸB activation in lipopolysaccharide-activated murine peritoneal macrophages.

BACKGROUND/AIM: Bursopentine (BP5) is a novel thiol-containing pentapeptide isolated from chicken bursa of Fabricius, and is reported to exert immunomodulatory effects on B and T lymphocytes. It has been found that some thiol compounds, such as glutathione (GSH) and N-acetylcysteine (NAC) protect living cells from oxidative stress. This led us to investigate whether BP5 had any ability to protect macrophages from oxidative stress as well as any mechanism that might underlie this process. METHODS: Murine peritoneal macrophages activated by lipopolysaccharide (LPS) (2 µg/ml) were treated with single bouts (0, 25, 50, and 100 µM) of BP5. RESULTS: BP5 potently suppressed the markers for oxidative stress, including nitric oxide (NO), reactive oxygen species (ROS), lipid peroxidation, and protein oxidation. It also decreased the expression and activity of inducible nitric oxide synthase (iNOS) and promoted a protective antioxidant state by elevating GSH content and by activating the expression and activity of certain key antioxidant and redox enzymes, including glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT). This suppressive effect on oxidative stress was accompanied by down-regulated expression and activity of nuclear factor kappa B (NF-κB). CONCLUSION: These findings demonstrate that BP5 can protect LPS-activated murine peritoneal macrophages from oxidative stress. BP5 may have applications as an anti-oxidative stress reagent.

Chemoproteomics reveals berberine directly binds to PKM2 to inhibit the progression of colorectal cancer.

Colorectal cancer is one of the most serious tumors and berberine can inhibit the recurrence and transformation of colorectal adenoma into colorectal cancer. However, the direct binding target proteins of berberine in inhibiting colorectal cancer remain unclear. In this study, the chemical proteomics method was used and demonstrated that berberine is directly bound to pyruvate kinase isozyme type M2 (PKM2) in colorectal cancer cells. The triangular N-O-O triangular structure of berberine contributed to hydrophobic interaction with I119 amino acid residues and π-π interaction with F244 amino acid residues of PKM2 protein. Moreover, berberine was shown to inhibit the reprogramming of glucose metabolism and the phosphorylation of STAT3, down regulate the expression of Bcl-2 and Cyclin D1 genes, ultimately inhibiting the progression of colorectal cancer. This study uncovered the direct binding target protein and mechanism of berberine to improve metabolic reprogramming in colorectal cancer, which is helpful to guide the optimization of berberine.

Dichlorido(dimethyl-formamide-κO)[1,4,7-tris-(2-cyano-ethyl)-1,4,7-triaza-cyclo-nonane-κN,N,N]nickel(II).

The title complex, [NiCl(2)(C(15)H(24)N(6))(C(3)H(7)NO)], is isomorphous with the Co(II) analogue. Three N-atom donors from the facially coordinating triaza macrocyclic ligand, one O-atom donor from dimethyl-formamide and two Cl(-) anions surround the Ni(II) ion in a distorted octa-hedral coordination geometry. Inter-molecular C-H⋯Cl and C-H⋯N hydrogen-bonding inter-actions link the complex mol-ecules into a three-dimensional supra-molecular architecture.

Dichloridobis[2-(2-chloro-ethyl)-1,2,3,4-tetra-hydro-pyrazino[1,2-a]benzimidazole-κN]cobalt(II).

In the title compound, [CoCl(2)(C(12)H(14)ClN(3))(2)], the central Co(II) ion lies on a twofold rotation axis and adopts a distorted tetra-hedral coordination geometry defined by two N atoms from two 2-(2-chloro-ethyl)-1,2,3,4-tetra-hydro-pyrazino[1,2-a]benzimidazole ligands and two chloride anions. The Cl atom located in the side chain of the ligand is involved in inter-molecular C-H⋯Cl hydrogen bonding, which links neutral complex units into a one-dimensional right-handed helical chain running along a crystallographic 4(1) axis. Such hydrogen-bonded helical chains are connected to each other to form a homochiral three-dimensional supra-molecular network. One C atom of the 2-chloro-ethyl chain is disordered over two positions, with site-occupancy factors of 0.52 and 0.48.

Dichlorido(dimethyl-formamide-κO)[1,4,7-tris-(2-cyano-ethyl)-1,4,7-triaza-cyclo-nonane-κN,N,N]cobalt(II).

The title compound, [CoCl(2)(C(15)H(24)N(6))(C(3)H(7)NO)], crystallizes as a monomeric complex. The coordination environment around the Co(II) center could be described as a distorted octa-hedron consisting of three N donors from the facially coordinating triaza macrocyclic ligand, one O donor from dimethyl-formamide and two Cl(-) ions. Neutral complex mol-ecules are associated via inter-molecular C-H⋯Cl hydrogen bonds to form two-dimensional layers. C-H⋯O hydrogen bonds are also present.

Modulations of Keap1-Nrf2 signaling axis by TIIA ameliorated the oxidative stress-induced myocardial apoptosis.

Mounting evidence has strongly implicated oxidative stress in the development of cardiac dysfunction, and myocardial apoptosis contributes to the pathogenesis of heart failure. Quantitative cardiac proteomics data revealed that pressure load by TAC resulted in a significant decline in mitochondrial metabolic activity, where TIIA (Tanshinone IIA sulfonate) treatment reversed it in vivo, which might be mediated by Nrf2. In NRVMs, TIIA treatment ameliorated H2O2-induced caspase-3/9 activations through the suppression of p38 and mTOR signaling pathways, where caspase-mediated cleavage of YY1 and PARP resulted in the defects in mitochondrial biogenesis and DNA repair, and this event finally led to cardiomyocyte apoptosis. Mass spectrometry analysis showed that TIIA hydrophobically interacted with Keap1 (the cytoplasmic repressor of Nrf2) and induced its degradation in vitro. Site-directed mutagenesis of Keap1 identified V122/V123/I125 to be the critical residues for the TIIA-induced de-dimerization and degradation of Keap1. Besides, TIIA treatment also epigenetically up-regulated Nrf2 gene transcription, where it hypomethylated the first 5 CpGs of Nrf2 promoter. Furthermore, cardiac-specific Nrf2 knockout mice exhibited the significantly dampened anti-apoptotic effects of TIIA.

Molecular visualizing and quantifying immune-associated peroxynitrite fluxes in phagocytes and mouse inflammation model.

Reactions of peroxynitrite (ONOO-) with biomolecules can lead to cytotoxic and cytoprotective events. Due to the difficulty of directly and unambiguously measuring its levels, most of the beneficial effects associated with ONOO- in vivo remain controversial or poorly characterized. Recently, optical imaging has served as a powerful noninvasive approach to studying ONOO- in living systems. However, ratiometric probes for ONOO- are currently lacking. Herein, we report the design, synthesis, and biological evaluation of F482, a novel fluorescence indicator that relies on ONOO--induced diene oxidation. The remarkable sensitivity, selectivity, and photostability of F482 enabled us to visualize basal ONOO- in immune-stimulated phagocyte cells and quantify its generation in phagosomes by high-throughput flow cytometry analysis. With the aid of in vivo ONOO- imaging in a mouse inflammation model assisted by F482, we envision that F482 will find widespread applications in the study of the ONOO- biology associated with physiological and pathological processes in vitro and in vivo.

Lysosomal ATP imaging in living cells by a water-soluble cationic polythiophene derivative.

Lysosomes in astrocytes and microglia can release ATP as the signaling molecule for the cells through ca(2+)-dependent exocytosis in response to various stimuli. At present, fluorescent probes that can detect ATP in lysosomes have not been reported. In this work, we have developed a new water-soluble cationic polythiophene derivative that can be specifically localized in lysosomes and can be utilized as a fluorescent probe to sense ATP in cells. PEMTEI exhibits high selectivity and sensitivity to ATP at physiological pH values and the detection limit of ATP is as low as 10(-11)M. The probe has low cytotoxicity, good permeability and high photostability in living cells and has been applied successfully to real-time monitoring of the change in concentrations of ATP in lysosomes though fluorescence microscopy. We also demonstrated that lysosomes in Hela cells can release ATP through Ca(2+)-dependent exocytosis in response to drug stimuli.

BODIPY-based azamacrocyclic ensemble for selective fluorescence detection and quantification of homocysteine in biological applications.

Considering the significant role of plasma homocysteine in physiological processes, two ensembles (F465-Cu(2+) and F508-Cu(2+)) were constructed based on a BODIPY (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene) scaffold conjugated with an azamacrocyclic (1,4,7-triazacyclononane and 1,4,7,10-tetraazacyclododecane) Cu(2+) complex. The results of this effort demonstrated that the F465-Cu(2+) ensemble could be employed to detect homocysteine in the presence of other biologically relevant species, including cysteine and glutathione, under physiological conditions with high selectivity and sensitivity in the turn-on fluorescence mode, while the F508-Cu(2+) ensemble showed no fluorescence responses toward biothiols. A possible mechanism for this homocysteine-specific specificity involving the formation of a homocysteine-induced six-membered ring sandwich structure was proposed and confirmed for the first time by time-dependent fluorescence spectra, ESI-MS and EPR. The detection limit of homocysteine in deproteinized human serum was calculated to be 241.4 nM with a linear range of 0-90.0 µM and the detection limit of F465 for Cu(2+) is 74.7 nM with a linear range of 0-6.0 µM (F508, 80.2 nM, 0-7.0 µM). We have demonstrated the application of the F465-Cu(2+) ensemble for detecting homocysteine in human serum and monitoring the activity of cystathionine ß-synthase in vitro.

A potent antitumor Zn2+ tetraazamacrocycle complex targeting DNA: the fluorescent recognition, interaction and apoptosis studies.

A Zn(2+) tetraazamacrocycle complex (2) bearing three naphthalene moieties has been prepared. Complex 2 recognizes, binds and causes damage to DNA, and shows considerable cytotoxicity against human cervical (HeLa), breast (MCF-7) and lung (NCI-H157) cancer cell lines with a different apoptotic pathway from that of cisplatin.