Synthesis of 1,8-Naphthyridines by the Ionic Liquid-Catalyzed Friedlander Reaction and Application in Corrosion Inhibition.

A several of basic ionic liquids (ILs) were synthesized as green solvents and catalysts for the preparation of 1,8-naphthyridyl derivatives via the Friedlander reaction. [Bmmim][Im] exhibited remarkable catalytic activity to achieve the synthetic targets, and the reaction conditions were optimized. The model product 2,3-diphenyl-1,8-naphthyridine (1,8-Nap), with carboxyethylthiosuccinic acid (CETSA) to form an IL corrosion inhibitor ([1,8-Nap][CETSA]), and its corrosion inhibition performance for Q235 steel in 1 M HCl were researched by weight loss measurements, and the results showed that the inhibition efficiency was 96.95% when the concentration of [1,8-Nap][CETSA] was 1 mM at 35 °C. The electrochemical test verified that [1,8-Nap][CETSA] acted as a mixed-type inhibitor but mainly exhibited cathodic behavior. The inhibitor adsorbed on the metal surface was further proved by surface topography analysis.

Geniposide protects pulmonary arterial smooth muscle cells from lipopolysaccharide-induced injury via α7nAchR-mediated TLR-4/MyD88 signaling.

Geniposide is a bioactive iridoid glucoside derived from Gardenia jasminoides that has proven anti-inflammatory effects against acute lung injury. The aim of this study was to determine whether geniposide could protect pulmonary arterial smooth muscle cells (PASMCs) from lipopolysaccharide (LPS)-induced injury and to explore the participation of α7 nicotinic acetylcholine receptor (α7nAChR), which was previously reported to suppress pro-inflammatory cytokine production in LPS-stimulated macrophages. In the present study, rat PASMCs were isolated and stimulated using LPS. The effect of geniposide on LPS-induced PASMC injury was then explored. Geniposide exerted anti-apoptotic and anti-inflammatory effects on LPS-treated PASMCs, as demonstrated by the downregulation of pro-apoptotic proteins and pro-inflammatory cytokines, respectively. Furthermore, the α7nAChR agonist PNU282987 accentuated the protective effect of geniposide against LPS-induced injury in PASMCs by inhibiting toll-like receptor-4/myeloid differentiation primary response 88 (TLR-4/MyD88) signaling and downregulating nuclear factor (NF)-κB expression. Conversely, methyllycaconitine, an inhibitor of α7nAChR, attenuated the effects of geniposide. These findings collectively suggested that in conjunction with geniposide, the activation of α7nAChR may contribute to further mitigating LPS-induced PASMC apoptosis and inflammation. In addition, the underlying mechanisms critically involve the NF-κB/MyD88 signaling axis. These results may provide novel insights into the treatment and management of lung diseases via geniposide administration.

Salvia miltiorrhiza improves Alzheimer's disease: A protocol for systematic review and meta-analysis.

BACKGROUND: Alzheimer's disease (AD) is an age-related neurodegenerative disease that is slowly becoming a global problem. Salvia miltiorrhiza (SM) has a history of thousands of years of use in China. In recent years, SM has been reported to have the effect of improving Alzheimer's disease. However, there is no systematic review of its efficacy and safety yet. Therefore, we propose a systematic review to evaluate the efficacy and safety of SM for AD patients. METHODS: Six databases will be searched: China National Knowledge Infrastructure (CNKI), China Biological Medicine (CBM), China Scientific Journals Database (CSJD), Wanfang database, PubMed, and EMBASE. The information is searched from January 2010 to July 2020. Languages are limited to English and Chinese. The primary outcomes include changes in the Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-Cog) and Activities of Daily Living scale (ADL). Additional outcomes include clinical effective rate and adverse event rate. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system will be used to assess the strength of the evidence. RESULTS: This systematic review will evaluate the efficacy and safety of SM in the treatment of Alzheimer's disease. CONCLUSION: This systematic review provides evidence as to whether SM is effective and safe for Alzheimer's disease patients. SYSTEMATIC REVIEW REGISTRATION: INPLASY202070066.

Inhibitory effects of piceatannol on human cytomegalovirus (hCMV) in vitro.

Human cytomegalovirus (hCMV) is a ubiquitous herpesvirus, which results in the establishment of a latent infection that persists throughout the life of the host and can be reactivated when the immunity is low. Currently, there is no vaccine for hCMV infection, and the licensed antiviral drugs mainly target the viral enzymes and have obvious adverse reactions. Thus, it is important to search for compounds with anti-hCMV properties. The present study aimed to investigate the suppressive effects of piceatannol on hCMV Towne strain infection and the putative underlying mechanisms using human diploid fibroblast WI-38 cells. Piceatannol supplementation prevented the lytic changes induced by hCMV infection in WI-38 cells. Furthermore, piceatannol suppressed the expression of hCMV immediate-early (IE) and early (E) proteins as well as the replication of hCMV DNA in a dose-dependent manner. Moreover, hCMV-induced cellular senescence was suppressed by piceatannol, as shown by a decline in the senescence-associated ß-galactosidase (SA-ß-Gal) activity and decreased production of intracellular reactive oxygen species (ROS). p16INK4a, a major senescence-associated molecule, was dramatically elevated by current hCMV infection that was attenuated by pre-incubation with piceatannol in a dose-dependent manner. These results demonstrated that piceatannol suppressed the hCMV infection via inhibition of the activation of p16INK4a and cellular senescence induced by hCMV. Together, these findings indicate piceatannol as a novel and potent anti-hCMV agent with the potential to be developed as an effective treatment for chronic hCMV infection.

Salidroside Delays Cellular Senescence by Stimulating Mitochondrial Biogenesis Partly through a miR-22/SIRT-1 Pathway.

Calorie restriction (CR) is a nongenetic intervention with a robust effect on delaying aging in mammals and other organisms. A mild stimulation on mitochondrial biogenesis induced by CR seems to be an important action mode for its benefits. Here, we reported that a component isolated from Rhodiola rosea L., salidroside, delays replicative senescence in human fibroblasts, which is related to its stimulation on mitochondrial biogenesis by activating SIRT1 partly resulted from inhibition on miR-22. Salidroside increased the mitochondrial mass that accompanied an increment of the key regulators of mitochondrial biogenesis including PGC-1α, NRF-1, and TFAM and reversed the mitochondrial dysfunction in presenescent 50PD cells, showing a comparable effect to that of resveratrol. SIRT1 is involved in the inducement of mitochondrial biogenesis by salidroside. The declined expression of SIRT1 in 50PD cells compared with the young 30PD cells was prevented upon salidroside treatment. In addition, pretreatment of EX-527, a selective SIRT1 inhibitor, could block the increased mitochondrial mass and decreased ROS production induced by salidroside in 50PD cells, resulting in an accelerated cellular senescence. We further found that salidroside reversed the elevated miR-22 expression in presenescent cells according to a miRNA array analysis and a subsequent qPCR validation. Enforced miR-22 expression by using a Pre-miR-22 lentiviral construct induced the young fibroblasts (30PD) into a senescence state, accompanied with increased senescence-related molecules including p53, p21, p16, and decreased SIRT1 expression, a known target of miR-22. However, salidroside could partly impede the senescence progression induced by lenti-Pre-miR-22. Taken together, our data suggest that salidroside delays replicative senescence by stimulating mitochondrial biogenesis partly through a miR22/SIRT1 pathway, which enriches our current knowledge of a salidroside-mediated postpone senility effect and provides a new perspective on the antidecrepitude function of this naturally occurring compound in animals and humans.

C-Terminal Domain of Hemocyanin, a Major Antimicrobial Protein from Litopenaeus vannamei: Structural Homology with Immunoglobulins and Molecular Diversity.

Invertebrates rely heavily on immune-like molecules with highly diversified variability so as to counteract infections. However, the mechanisms and the relationship between this variability and functionalities are not well understood. Here, we showed that the C-terminal domain of hemocyanin (HMC) from shrimp Litopenaeus vannamei contained an evolutionary conserved domain with highly variable genetic sequence, which is structurally homologous to immunoglobulin (Ig). This domain is responsible for recognizing and binding to bacteria or red blood cells, initiating agglutination and hemolysis. Furthermore, when HMC is separated into three fractions using anti-human IgM, IgG, or IgA, the subpopulation, which reacted with anti-human IgM (HMC-M), showed the most significant antimicrobial activity. The high potency of HMC-M is a consequence of glycosylation, as it contains high abundance of α-d-mannose relative to α-d-glucose and N-acetyl-d-galactosamine. Thus, the removal of these glycans abolished the antimicrobial activity of HMC-M. Our results present a comprehensive investigation of the role of HMC in fighting against infections through genetic variability and epigenetic modification.

Ebola: Emergency preparedness and perceived response of Malaysian health care providers.

We studied the emergency preparedness and perceived response for Ebola virus disease among various health care providers in Malaysia using a self-report questionnaire. Most of the health care providers felt that they were able to respond to Ebola virus disease and were aware of the level of preparedness needed during emergency.

Development and novel therapeutics in hepatocellular carcinoma: a review.

This review summarizes the epidemiological trend, risk factors, prevention strategies such as vaccination, staging, current novel therapeutics, including the drugs under clinical trials, and future therapeutic trends for hepatocellular carcinoma (HCC). As HCC is the third most common cause of cancer-related death worldwide, its overall incidence remains alarmingly high in the developing world and is steadily rising across most of the developed and developing world. Over the past 15 years, the incidence of HCC has more than doubled and it increases with advancing age. Chronic infection with hepatitis B virus is the leading cause of HCC, closely followed by infection with hepatitis C virus. Other factors contributing to the development of HCC include alcohol abuse, tobacco smoking, and metabolic syndrome (including obesity, diabetes, and fatty liver disease). Treatment options have improved in the past few years, particularly with the approval of several molecular-targeted therapies. The researchers are actively pursuing novel therapeutic targets as well as predictive biomarker for treatment of HCC. Advances are being made in understanding the mechanisms underlying HCC, which in turn could lead to novel therapeutics. Nevertheless, there are many emerging agents still under clinical trials and yet to show promising results. Hence, future therapeutic options may include different combination of novel therapeutic interventions.

Complexome of Escherichia coli cytosolic proteins under normal native conditions.

The interactions between proteins are important for the majority of biological functions and the interacting proteins are usually assembled into a complex. Knowing a set of protein complexes of a cell (complexome) is, therefore, essential for a better understanding and global view of cell functions. To visualize and identify the protein complexome of E. coli K-12 under normal native conditions on a proteome-wide scale, we developed an integrated proteomic platform with the combination of 2-D native/SDS-PAGE-based proteomics with co-immunoprecipitation, far-Western blotting, His-tag affinity purification and functional analysis, and used it to investigate the E. coli cytosolic complexome. A total of 24 distinct heteromeric and 8 homomeric protein complexes were identified. These complexes mainly contributed to glycolysis/gluconeogenesis, bioinformation processing, and cellular processes. Of the 24 hetereomeric complexes, 16 were reported for the first time, and 2 known complexes contained novel components that have not been reported previously based on DIP database search. Among them, RpoC-RpsA-Tig-GroL was found to be involved in transcriptional and co-translational folding, and EF-G-TufA-Tsf-RpsA linked a protein synthesis site with protein translational elongation factors. This systematic proteome analysis provides new insights into E. coli molecular systems biology.

Gut CaVP is an innate immune protein against bacterial challenge in amphioxus Branchiostoma belcheri.

The importance of calcium-binding proteins in immune response of vertebrates is determined, but whether they have the role in invertebrates is largely unknown. In the present study, phylogenetic analysis indicated that calcium vector protein (CaVP), a protein unique to amphioxus, shared 68% similarity in amino acid sequence with human and mouse calmodulin (CaM). CaVP cDNA was cloned into a bacterial vector pET-32a, and its His-tagged fusion protein was produced in Eschherichia coli cells (BL21). The recombinant CaVP was purified by Ni-NTA column and SDS-PAGE, and then utilized for antibody preparing. The prepared antibodies could recognize amphioxus CaVP with high specificity. Further analysis by Western blotting showed that CaVP was detected in muscle and humoral fluid of normal animals and appeared in gut of bacterial immunized or challenged amphioxus. Interestingly, gut CaVP was significantly higher in a healthy sub-group than a wounded sub-group post bacterial challenge. This response was detected strongly in immunization and challenge by the same Gram-negative bacterium Vibro parahaemolyticus and weakly in immunization by V. parahaemolyticus and then challenge by Gram-negative Aeromonas hydrophila, whereas no any feedback was found in immunization by V. parahaemolyticus and challenge by Gram-positive Staphylococcus aureus. These findings indicate the importance of gut CaVP in response to bacterial challenge.

The localization of hnRNP A2/B1 in nuclear matrix and the aberrant expression during the RA-induced differentiation of human neuroblastoma SK-N-SH cells.

Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 is involved in the synthesis of RNA. Its expression is up-regulated in many tumor cell lines. In this study, we investigated the distribution of hnRNP A2/B1 in the nuclear matrix, including its co-localization with expression products of related genes. Results from 2-DE PAGE and MS showed that hnRNP A2/B1 is involved with components of nuclear matrix proteins of SK-N-SH cells, and that its expression level is down-regulated after retinoic acid (RA) treatment. Protein immunoblotting results further confirm the existence of hnRNP A2/B1 in the nuclear matrix, as well as its down-regulation after RA treatment. Immunofluorescence microscopy observation showed that hnRNP A2/B1 localized in nuclear matrix of SK-N-SH cells and its distribution regions were altered after RA treatment. Laser scanning confocal microscopy observation showed that hnRNP A2/B1 co-localized with c-Myc, c-Fos, P53, and Rb in SK-N-SH cells. The co-localized region was altered as a result of RA treatment. Our data proved that hnRNP A2/B1 is a nuclear matrix protein and can be up-regulated in human neuroblastoma. The expression and distribution of hnRNP A2/B1 can affect the differentiation of SK-N-SH cells, as well as its co-localization with related oncogenes and tumor suppressor genes.

Gut SCP is an immune-relevant molecule involved in the primary immunological memory or pattern recognition in the amphioxus Branchiostoma belcheri.

To understand the role of calcium-binding proteins of invertebrates in immunological response, amphioxus sarcoplasmic calcium-binding protein (SCP) was investigated in the present study. Following gene cloning, recombinant protein expression and purification and antibody preparation, the expression and alteration of SCP in the response to bacterial challenge were detected using Western blotting. SCP was not detected in the branchia, humoral fluid, gonad or in the gut of wounded animals, but it was abundant in muscle and appeared in the gut of healthy animals using Vibrio parahaemolyticus immunization and challenge. Furthermore, whether gut SCP possessed anamnestic response was investigated using cross-immune challenge between Gram-positive and -negative bacteria. Gut SCP showed stronger anamnestic activity or pattern-recognition in response to Gram-negative bacterium V. parahaemolyticus than Gram-positive bacterium Staphylococcus aureus. The response was faster and more species-specific to V. parahaemolyticus, whereas it was slower and longer to S. aureus. The reason why the response showed significant difference between Gram-positive and -negative bacteria awaits investigation. These results indicate that gut SCP is an immune-relevant molecule involved in the primary immunological memory or pattern recognition in the amphioxus Branchiostoma belcheri.

Characterization of outer membrane proteins of Escherichia coli in response to phenol stress.

Gram-negative bacteria are generally more tolerant to disinfectants than Gram-positive bacteria due to outer membrane (OM) barrier, but the tolerant mechanism is not well characterized. We have utilized comparative proteomic methodologies to characterize the OM proteins of E. coli K-12 K99+ in response to phenol stress and found that nine proteins were altered significantly. They were OM proteins OmpA, FadL, LamB, and OmpT, cytoplasmic-associated proteins AceA and EF-Tu, inner membrane protein AtpB, putative capsid protein Q8FewO, and unknown location protein Dps. They were reported here for the first time to be phenol-tolerant proteins. The alteration and functional characterization of the four OM proteins were further investigated using western blotting, genetically modified strains with gene deletion and gene complementation approaches. Our results characterized the functional OM proteins of E. coli in resistance to phenol, and provide novel insights into the mechanisms of bacterial disinfectant-tolerance and new drug targets for control of phenol-resistant bacteria.

Aberrant expression and localization of hnRNP-A2/B1 is a common event in human gastric adenocarcinoma.

BACKGROUND AND AIM: Nuclear-matrix proteins can be proteomic markers for cancer lesions. The present study aimed to determine the roles of heterogeneous nuclear ribonucleoproteins--A2 and B1 (hnRNP-A2/B1) in human gastric carcinogenesis. METHODS: Human gastric cancer and non-cancerous tissues were collected for immunohistochemical analysis. Proteomics technique, Western blot, laser confocal microscope, and real-time quantitative reverse transcription-polymerase chain reaction were performed to determine the aberrant expression of nuclear-matrix proteins. RESULTS: hnRNP-A2/B1 existed in the nuclear matrix of gastric cancer cells, and its expression was enhanced in human gastric cancer and decreased by hexamethylene bisacetamide. The colocalization of hnRNP-A2/B1 with c-myc, c-fos, p53, and Rb was translocated from the nucleolus to the cytoplasm during the differentiation of tumor cells. CONCLUSIONS: hnRNP-A2/B1 affected tumor cell differentiation through interaction with oncogenes and tumor-suppressor genes, and it was overexpressed in human gastric cancer. We postulate that hnRNP-A2/B1 could serve as a biomarker for the diagnosis of human gastric cancer.

Localization of prohibitin in the nuclear matrix and alteration of its expression during differentiation of human neuroblastoma SK-N-SH cells induced by retinoic acid.

The nuclear matrix-intermediate filament system of human neuroblastoma SK-N-SH cells before and after retinoic acid (RA) treatment was selectively extracted and the distribution of prohibitin (PHB) in the nuclear matrix, as well as its colocalization with related genes, was observed. Results of two-dimensional gel electrophoresis (2-DE), mass spectrometry (MS) identification, and protein immunoblotting all confirm that PHB was present in the components of SK-N-SH nuclear matrix proteins and was down-regulated after RA treatment. Immunofluorescence microscopy observations show that PHB was localized in the nuclear matrix and its distribution was altered due to RA treatment. Laser confocal microscopy results reveal that PHB colocalized with the expression products of c-myc, c-fos, p53, and Rb, but the colocalization region was altered after RA treatment. Our results prove that PHB is a nuclear matrix protein and is localized in nuclear matrix fibers. The distribution of PHB in SK-N-SH cells and its colocalization with related proto-oncogenes and tumor suppressor genes suggest that PHB plays pivotal roles in the differentiation of SK-N-SH cells and deserves further study.

Complexome of Escherichia coli envelope proteins under normal physiological conditions.

The interactions between proteins are important for very numerous, if not all, biological functions, and the interacted proteins might form part of a protein complex. To understand the protein complexes of a cell, complexome, is essential for a better understanding of cell functions. In the present study, we have performed a systematic fractionation and analysis of Escherichia coli K-12 membrane proteins under proximately normal physiological conditions using two-dimensional native/SDS-PAGE (N-PAGE)-based proteomics. Sixteen distinct heteromeric protein complexes including their associated periplasmic and/or cytoplasmic proteins were determined based on the distribution patterns of the protein spots in the gel and proteins' functions. Out of these 16 complexes, 10 were novel ones, in which six were reported here for the first time and the other four contained novel components that have not been reported previously. Interestingly, YaeT, one of the most important protein components in the well-known outer membrane assembly complex, was found to interact with the energy generation system Nar/Fdh-N. This finding may modify the previously well-accepted concept that energy supply is not required for outer membrane assembly, and suggest that the interaction of membrane proteins with energy supply system is a characteristic feature of E. coli envelope protein network.

Localization of nucleophosmin in nuclear matrix and changes in its expression during the differentiation of human neuroblastoma induced by retinoic acid.

In this article, we selectively extracted the nuclear matrix and intermediate filament system of human neuroblastoma SK-N-SH cells pre- and post-treated with retinoic acid (RA). The distribution of nucleophosmin (NPM) in the nuclear matrix and its colocalization with several products of related genes were investigated. Results from two-dimensional gel electrophoresis and MALDI-TOF showed that NPM was a component of the nuclear matrix and its expression in SK-N-SH cells post-treated with RA was down-regulated. Immunofluorescent microscopy observations further showed that NPM was localized in the nuclear matrix of SK-N-SH cells, and its expression level and distribution were altered after treatment with RA. The colocalization of NPM with c-myc, c-fos, p53, and Rb in SK-N-SH cells was observed under a laser scanning confocal microscope, but the colocalization region was changed by RA. Our results prove that NPM is a nuclear matrix protein, which is localized in nuclear matrix fibers. The colocalization of NPM with its related genes and oncogenes affect the differentiation of SK-N-SH cells. The expression of NPM and its distribution in the process of cell differentiation deserve more intensive investigation.