ABSTRACT
Iron has a key role in the activation of the autophagic pathway in rats with intracerebral hemorrhage (ICH), and hepcidin has the ability to reduce brain iron in ICH-rats. We therefore hypothesized that hepcidin might be able to inhibit autophagy by reducing iron in an ICH brain. Here, we investigated the effects of Ad-hepcidin and/or hepcidin peptide on autophagic activities in ICH models in vitro and in vivo. We demonstrated that ad-hepcidin and hepcidin peptide both inhibited hemin-induced increase in LC3-II/LC3-I conversion ratio and reversed the reduction in p62 content in cortical neurons in vitro. We also showed that ad-hepcidin inhibited ICH-induced increase in LC3-II/LC3-I conversion ratio and reversed ICH-induced reduction in p62 content in the brain cortex of rats in vivo. Based on these findings plus previous data on the effects of ad-hepcidin and/or hepcidin peptide on iron contents in ICH models, we suggested that hepcidin-induced inhibition of autophagy might be mediated via reducing iron in hemin-treated neurons in vitro and ICH-rat brain in vivo.
Subject(s)
Autophagy , Cerebral Hemorrhage/metabolism , Hepcidins/metabolism , Adenoviridae/genetics , Animals , Cells, Cultured , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Genetic Vectors/genetics , Hepcidins/genetics , Male , Microtubule-Associated Proteins/metabolism , Neurons/metabolism , Rats , Rats, Sprague-Dawley , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequestosome-1 Protein/metabolismABSTRACT
Ischemic preconditioned (IP) neurons protect astrocytes against ischemia/reperfusion (I/R)-induced injury by inhibiting oxidative stress. However, the relevant mechanisms are unknown. Based on the role of nuclear factor-κB (NF-κB) in cell survival and adaption to oxidative stress, we hypothesized that NF-κB might be associated with astroprotection induced by IP neurons via upregulation of antioxidant enzymes. Here, we investigated the effects of IP neurons on NF-κB activation, cell viability, reactive oxygen species (ROS), expression of antioxidant enzymes, erythropoietin (EPO), and tumor necrosis factor α (TNF-α), in the presence or absence of BAY11-7082 (an NF-κB inhibitor), anti-EPO, and anti-TNF-α antibodies, in astrocytes treated with or without I/R. We found that IP neurons could keep NF-κB activation at a relatively higher but beneficial level, and in turn, upregulated the activity of antioxidant enzymes and hence enhanced cell viability and reduced ROS in I/R treated astrocytes. The results collectively indicated that IP neurons are able to significantly inhibit the I/R-induced NF-κB overactivation, probably via EPO and TNF-α, being essential for IP neuron-induced astroprotection under the conditions of I/R. We concluded that NF-κB-mediated antioxidative stress is one of the mechanisms by which IP neurons protect astrocytes against I/R injury.
Subject(s)
Astrocytes/metabolism , Cerebral Cortex/metabolism , NF-kappa B/metabolism , Neurons/metabolism , Paracrine Communication , Reperfusion Injury/prevention & control , Animals , Antioxidants/metabolism , Astrocytes/enzymology , Astrocytes/pathology , Cell Hypoxia , Cells, Cultured , Cerebral Cortex/pathology , Culture Media, Conditioned/metabolism , Erythropoietin/metabolism , Glucose/deficiency , Neurons/pathology , Oxidative Stress , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Signal Transduction , Tumor Necrosis Factor-alpha/metabolismABSTRACT
A Gram-stain-positive, aerobic, coccoid-shaped, non-spore-forming actinobacterial strain, designated M5W7-7T, was isolated from a hot spring soil sample collected from Anshan, Liaoning province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain M5W7-7T clustered closely with species of the genus Kocuria, and showed the highest sequence similarity of 97.1â% to Kocuria subflava YIM 13062T. Strain M5W7-7T grew at 10-37 °C (optimum, 37 °C), pH6.0-11.0 (pH 6.0-7.0) and in the presence of 0-7â% (w/v) NaCl (0â%). Substrate mycelia and aerial mycelia were not formed, and diffusible pigments were not observed on any media tested. Strain M5W7-7T contained MK-6(H2) and MK-7(H2) as the dominant menaquinones. The polar lipid profile of strain M5W7-7T contained diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, an unidentified phospholipid and an unidentified lipid. The predominant whole-cell sugars were galactose and glucose. The predominant fatty acid was anteiso-C15â:â0. The DNA G+C content of strain M5W7-7T was 67.0 mol%. On the basis of phylogenetic relationships, phenotypic characterization and chemotaxonomic analyses, strain M5W7-7T represents a novel species of the genus Kocuria, for which the name Kocuriasoli sp. nov. is proposed. The type strain is M5W7-7T (=KCTC 49195T =CGMCC 1.13744T).
Subject(s)
Hot Springs/microbiology , Micrococcaceae/classification , Phylogeny , Soil Microbiology , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Glycolipids/chemistry , Micrococcaceae/isolation & purification , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/chemistryABSTRACT
A region-specific regulation of inflammation on the expression hepcidin in the brain has been demonstrated, however, it remains unknown whether there is also a cell-specific regulation of inflammation on hepcidin in the brain. Here, we investigated the effects of lipopolysaccharides (LPS) on the expression of hepcidin mRNA and also the expression of IL-6 mRNA, the phosphorylation of STAT3 and the expression of ferroportin 1 (Fpn1) and ferritin light chain (Ft-L) proteins in neurons and astrocytes obtained from wild type (IL-6+/+) and IL-6 knockout (IL-6-/-) mice. We demonstrated that the responses of the expression of hepcidin and IL-6 mRNAs, the phosphorylation of STAT3, and the expression of Fpn1 protein to LPS in IL-6+/+ astrocytes and also the responses of the expression of hepcidin mRNA, the phosphorylation of STAT3 and the expression of Fpn1 protein to IL-6 in IL-6-/- astrocytes were much stronger than those in IL-6+/+ and IL-6-/- neurons. A significant increase in Ft-L was found in LPS-treated IL-6+/+ and IL-6-treated IL-6-/- astrocytes, but not in LPS-treated IL-6+/+ and IL-6-treated IL-6-/- neurons. Our findings provide in vitro evidence for the existence of a cell-specific regulation of LPS on the expression of hepcidin and also Ft-L in the brain.
Subject(s)
Astrocytes/drug effects , Hepcidins/metabolism , Lipopolysaccharides/pharmacology , Neurons/drug effects , Animals , Apoferritins/metabolism , Cation Transport Proteins/metabolism , Gene Knockout Techniques , Interleukin-6/genetics , Interleukin-6/metabolism , Male , Mice, Inbred C57BL , STAT3 Transcription Factor/metabolismABSTRACT
A Gram-positive, aerobic, coccus-shaped, non-spore-forming actinobacterium, designated strain M1HQ-2T, was isolated from a surface-sterilized bark of Scutellaria baicalensis Georgi collected from Guizhou, China and tested using a polyphasic approach to determine its taxonomic position. Strain M1HQ-2T grew at 4-37 °C (optimum, 30 °C), pH 5.0-11.0 (pH 8.0) and in the presence of 0-15â% (w/v) NaCl (1-3â%). Substrate mycelia and aerial mycelia were not formed, and diffusible pigments were not observed on any media tested. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain M1HQ-2T belonged to the genus Brachybacterium and had the highest 16S rRNA gene sequence similarity of 97.6â% to Brachybacteriumsquillarum M-6-3T. Strain M1HQ-2T contained MK-7 as the dominant menaquinone. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The polar lipids profile of strain M1HQ-2T contained diphosphatidylglycerol, phosphatidylglycerol, an unidentified phospholipid and an unidentified lipid. The predominant fatty acids were anteiso-C15â:â0 and anteiso-C17â:â0. The DNA G+C content of strain M1HQ-2T was 71.0 mol%. The average nucleotide identity value between strain M1HQ-2T and type strain of Brachybacterium sacelli was 76.7â%. The estimated DNA-DNA hybridization value between strain M1HQ-2T and type strain of B. sacelli was 20.6â%. On the basis of phylogenetic analysis, chemotaxonomic characteristics and phenotypic data, strain M1HQ-2T represents a novel species of the genus Brachybacterium, for which the name Brachybacteriumendophyticum sp. nov. is proposed. The type strain is M1HQ-2T (=KCTC 49087T=CGMCC 1.16391T).
Subject(s)
Actinomycetales/classification , Phylogeny , Scutellaria baicalensis/microbiology , Actinomycetales/genetics , Actinomycetales/isolation & purification , Bacterial Typing Techniques , Base Composition , Cell Wall/chemistry , China , DNA, Bacterial/genetics , Diaminopimelic Acid/chemistry , Fatty Acids/chemistry , Nucleic Acid Hybridization , Peptidoglycan/chemistry , Phospholipids/chemistry , Plant Bark/microbiology , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistryABSTRACT
This study performed an optimization of the fermentation conditions to activate the expression of the zunyimycin family biosynthesis genes of the zunyimycin-producing streptomycetes strain Streptomyces sp. FJS31-2. Bioassay-guided isolation and purification by varied chromatographic methods yielded two new compounds of the zunyimycin derivatives, namely, 31-2-7 and 31-2-8, accompanied with three known anthrabenzoxocinones family members of zunyimycin A, BE24566B, and chloroanthrabenzoxocinone. Their structures were elucidated by NMR, HRESIMS, IR, UV, and CD. Results showed that these two compounds were structurally similar to the previously reported compound zunyimycin A but differed in positions and number of chlorine atom substitution. The two novel compounds were called zunyimycins B and C. Antibacterial activity assay indicated that zunyimycin C showed a good inhibitory effect on the methicillin-resistant Staphylococcus aureus and Enterococci.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Enterococcus/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Streptomyces/metabolism , Anti-Bacterial Agents/biosynthesis , Circular Dichroism , Fermentation , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Molecular StructureABSTRACT
OBJECTIVES: To determine the prevalence of overweight and obesity in children and adolescents aged 7-15 years in Longquanyi District of Chengdu and its association with consumptions of meat, dietary fat and fatty-acids. METHODS: A total of 1 811 children and adolescents aged 7-15 years in Longquanyi District were selected using stratified cluster sampling strategy. Their body mass, height and waist circumference were measured. The prevalence of overweight/obesity was estimated based on body mass index (BMI), body mass index standard deviation score (BMI SDS), and waist-to-height ratio (WHtR). Daily consumptions of meat, dietary fat and fatty-acids were calculated using data collected through a food frequency questionnaire and 3-d 24 h dietary recall. The children with overweight/obesity were compared with those with normal body mass in food/nutrient consumptions using Wilcoxon tests. The BMI SDS, WHtR, and prevalence of overweight and obesity were also compared between those having low, moderate and high food/nutrient consumptions using Chi-square tests or Kruskal-Wallis tests. RESULTS: About 10.34% and 6.59% of participants were found to be overweight and obese, respectively. Boys had higher prevalence of overweight (12.05%) and overweight/obesity (18.97%) than girls (8.55%, 14.80%) ( P<0.05). Girls consumed more meat (including red meat and white meat), saturated fatty-acid (SFA) and monounsaturated fatty-acid (MUFA) than boys ( P<0.05). The consumptions of meat (both red meat and white meat), SFA and MUFA increased with age ( P<0.05). Overweight/obese girls consumed more SFA, MUFA and fat (%EN) than those of normal weight. The BMI SDS and WHtR of girls increased with fat (%EN) consumptions ( P<0.05). The BMI SDS of girls also increased with MUFA consumptions ( P<0.05). CONCLUSIONS: Consumptions of red meat, dietary fat, SFA, and MUFA are associated with overweight/obesity of girls aged 7-15 years in Chengdu. Further studies are needed to understand the gender differences.
Subject(s)
Dietary Fats , Fatty Acids , Meat , Obesity/epidemiology , Overweight/epidemiology , Adolescent , Body Mass Index , Child , China/epidemiology , Cross-Sectional Studies , Diet , Female , Humans , Male , Prevalence , Surveys and Questionnaires , Waist Circumference , Waist-Height RatioABSTRACT
Genome mining is an effective tool used to discover novel natural products from actinomycetes. Genome sequence analysis of Streptomyces sp. FJS31-2 revealed the presence of one putative type II polyketide gene cluster (ABX), which may correspond to type II polyketide products including BE-24566B and its chloro-derivatives. The addition of natural humus acid successfully activated the biosynthsis of the abx gene cluster. BE-24566B and its chloro-derivatives, named zunyimycin A, were also detected. The targeted deletion of the polyketide skeleton synthesis genes such as abxp, abxk, and abxs was performed in the wild strain to identify the gene cluster for BE-24566B biosynthesis.
Subject(s)
Multigene Family , Polyketides/metabolism , Streptomyces/genetics , Streptomyces/metabolism , Anthraquinones/metabolism , Gene Order , Metabolome , Metabolomics/methods , Molecular Structure , Polyketides/chemistryABSTRACT
OBJECTIVE: To investigate the intakes of dietary calcium/dairy and the current prevalence of overweight and obesity among children and adolescents aged 7-15 in Longquanyi District, Chengdu, and to explore the association of dietary calcium and dairy intake with overweight/obesity. METHODS: 1738 children and adolescents were recruited in the cross-sectional study using cluster random sampling method. Information on dietary calcium and dairy intakes was collected using 24-hour dietary recall and food frequency questionnaire (FFQ). Height, weight and waist circumference were measured to calculate body mass index (BMI)/waist-to-height ratio (WHtR) and body mass index standard deviation (BMI SDS). Overweight/obesity was defined based on the criteria of Working Group on Obesity in China (WGOC). Participants were grouped into 3 categories indicating lower, moderate and higher intakes of dietary calcium and dairy, respectively. The association of dietary calcium and dairy consumption with (BMI SDS) /WHtR and the prevalence of overweight/obesity was analyzed after being stratified by gender and age. RESULTS: The prevalence of overweight/obesity in boys and girls were 11.92%/7.04% and 8.04%/6.30%, respectively. The intake of dietary calcium and dairy in girls were much higher than that in boys (P < 0.0001). Among boys aged 7-9 years, those with higher consumption of dairy had the higher BMI SDS (P = 0.01). Among boys aged 10-12 years, those with higher consumption of dietary calcium had the lowest prevalence of overweight (P = 0.03). However, similar results were not observed among girls. CONCLUSIONS: Dietary calcium and dairy intakes seemed to be related to overweight/ obesity in boys, however the associations were inconsistent among different age groups. Associations between consumption of calcium, dairy and overweight/obesity were not found among girls.
Subject(s)
Calcium, Dietary/administration & dosage , Diet , Obesity/epidemiology , Overweight/epidemiology , Adolescent , Body Mass Index , Body Weight , Child , China , Cross-Sectional Studies , Female , Humans , Male , Nutrition Surveys , Prevalence , Waist Circumference , Waist-Height RatioABSTRACT
OBJECTIVE: To determine the association between intake of dietary fiber and pubertal development among children and adolescents in Chengdu. METHODS: A cross-sectional survey was undertaken in 1 340 children and adolescents aged 9-15 years. Data about dietary intake were collected through 24-h dietary self-recall. Pubertal development was measured by trained investigators using Tanner criteria. Consumptions of total fiber and fiber from different sources were compared among the participants with different stages of pubertal development. RESULTS: Data from 1 328 children and adolescents were analyzed. Boys (n = 667) at a later stage of pubertal development consumed less total fiber and fruit fiber than those at an earlier stage (P < 0.05). Similarly, girls (n = 651) at a later stage of pubertal development consumed less fruit fiber than those at an earlier stage (P < 0.05). CONCLUSION: Dietary fiber intake, especially fruit fiber, is lower in children and adolescents with early commencement of puberty development. Further studies are needed to establish the relationship between dietary fiber and pubertal development.
Subject(s)
Diet , Dietary Fiber , Puberty , Adolescent , Adolescent Development , Child , China , Cross-Sectional Studies , Female , Humans , MaleABSTRACT
In order to obtain the natural products synthesized by the three putative xiamycin biosynthesis gene clusters which were predicted via antiSMASH during the genome mining of marine Streptomyces sp. FXJ 7.388, Streptomyces sp. FXJ 8.012, and Streptomyces olivaceus FXJ 7.023. Sixteen genes involved in xiamycin assembly, modification, and regulation with higher identity than the newest reported xiamycin biosynthetic gene cluster from marine Streptomyces sp. SCSIO 02999, Streptomyces sp. HKI0576, and Streptomyces sp. FXJ 7.388 were discovered via gene cluster comparative analysis. A ribosome engineering strategy was adopted to activate such cryptic gene clusters with different final concentrations antibiotics that act on the ribosome, and two indolosesquiterpenes were isolated from idlethaldose streptomycin-resistant Streptomyces sp. FXJ 7.388 strains. However, no such product was detected in Streptomyces sp. FXJ 8.012 and Streptomyces olivaceus FXJ 7.023 under the same treatment. This result suggested that these genes might hold the least gene content for xiamycin biosynthesis.
Subject(s)
Marine Biology , Multigene Family , Sesquiterpenes/metabolism , Streptomyces/genetics , Streptomyces/metabolismABSTRACT
OBJECTIVE: To determine the associations between meat, dairy and zinc intake and pubertal development in adolescents in Chengdu. METHODS: A total of 1320 children and adolescents aged 9-15 years in Chengdu were recruited using a stratified cluster sampling strategy. Dietary intake was assessed by the food frequency questionnaire (FFQ) and 3-day 24-hour dietary recall. Pubertal development was evaluated through physical examinations. Consumptions of meat and dairy, and zinc intake were compared between groups with different levels of pubertal development according to the Tanner criteria. RESULTS: The median age of spermarche was 13. 00 years. The boys who had had spermarche consumed more meat (including red meat) and dairy products than those who had not yet (P<0. 05). Daily consumption of total meat was positively correlated with the level of pubertal development (P<0. 05). The median age of menarche was 12. 11 years. The girls who had had menarche consumed more meat and less diiry products than those who had not yet (P<0. 05). Daily consumption of dairy products was negatively associated with breast development and the level of pubertal development (P < 0. 05). CONCLUSION: Consumptions of meat, red meat and dairy products are associated with pubertal development in adolescents in Chengdu. However, the differences between boys and girls warrant further studies.
Subject(s)
Adolescent Nutritional Physiological Phenomena , Dairy Products , Diet , Meat , Zinc , Adolescent , Child , China , Female , Humans , MaleABSTRACT
Norcantharidin (NCTD) is a demethylated analogue of cantharidin. It was recently demonstrated that NCTD reduces iron contents in the liver and spleen of mice in vivo, indicating that NCTD can affect iron metabolism via hepcidin. Here, we investigated the effects of NCTD on expression of iron storage protein ferritin-light chain (Ft-L), transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), ferroportin 1 (Fpn1), hepcidin, iron regulatory protein 1 (IRP1), IL-6, p-JAK2 and p-STAT3 in lipopolysaccharides (LPS)-treated RAW264.7 cells in vitro via Real-time PCR and Western blotting analysis. We demonstrate that NCTD down-regulates Ft-L, hepcidin, IL-6, pJAK2, pSTAT3 and up-regulates TfR1, DMT1, Fpn1 and IRP1 expression in LPS treated cells, showing that NCTD can inhibit hepcidin via the IL-6/JAK2/STAT3 signalling pathway and also increase TfR1, DMT1 and Fpn1 expression via down-regulating hepcidin and up-regulating IRP1. Our findings provide further evidence in vitro for the role of NCTD in iron metabolism.
Subject(s)
Bridged Bicyclo Compounds, Heterocyclic , Hepcidins , Interleukin-6 , Mice , Animals , Hepcidins/genetics , Hepcidins/metabolism , Interleukin-6/genetics , Interleukin-6/metabolism , Down-Regulation , Lipopolysaccharides/pharmacology , Iron/metabolism , Macrophages/metabolismABSTRACT
Renal tubulointerstitial fibrosis (RTIF) is a common feature and inevitable consequence of all progressive chronic kidney diseases, leading to end-stage renal failure regardless of the initial cause. Although research over the past few decades has greatly improved our understanding of the pathophysiology of RTIF, until now there has been no specific treatment available that can halt the progression of RTIF. Norcantharidin (NCTD) is a demethylated analogue of cantharidin, a natural compound isolated from 1500 species of medicinal insect, the blister beetle (Mylabris phalerata Pallas), traditionally used for medicinal purposes. Many studies have found that NCTD can attenuate RTIF and has the potential to be an anti-RTIF drug. This article reviews the recent progress of NCTD in the treatment of RTIF, with emphasis on the pharmacological mechanism of NCTD against RTIF.
Subject(s)
Kidney Diseases , Humans , Kidney Diseases/drug therapy , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , FibrosisABSTRACT
Endometrial cancer (EC) remains a prevalent gynecological disease with a continuously rising incidence and fatality rate. Acyl coenzyme A: cholesterol acyltransferase 2 (ACAT2) has been commonly perceived as a tumor promoter in multiple human malignancies. This study was conducted to specify the role and mechanism of ACAT2 in EC, which has not been covered. The expression and prognostic significance of ACAT2 in EC samples were respectively analyzed by the ENCORI and Kaplan-Meier plotter databases. RT-qPCR and western blot examined ACAT2 and forkhead box protein A2 (FOXA2) expression in EC cells. The CCK-8 method, colony formation, and EdU staining assays detected cell proliferation. The cell cycle was detected by flow cytometry analysis. Wound healing and Transwell assays, respectively, estimated cell migration and invasion. The thiobarbituric acid reactive species (TBARS) method and BODIPY 581/591 C11 probe detected lipid peroxidation levels. FerroOrange staining estimated intracellular iron level. Western blot examined the expression of epithelial-mesenchymal transition (EMT) and ferroptosis-associated proteins. The human TFDB database predicted the binding of FOXA2 with the ACAT2 promoter, which was substantiated by ChIP and luciferase reporter assays. As a result, ACAT2 expression was increased in EC tissues and cells and associated with poor survival outcomes in EC patients. ACAT2 deletion might hinder EC cell proliferation, migration, invasion, and EMT while stimulating cell cycle arrest. Moreover, ACAT2 silencing promoted the ferroptosis of EC cells. Also, FOXA2 inactivated the transcription of ACAT2 through binding with the ACAT2 promoter. FOXA2 interference could promote the proliferation, migration, invasion, EMT, cell cycle, and ferroptosis of ACAT2-silenced EC cells, which was partially reversed by the ferroptosis activator erastin. Conclusively, ACAT2 transcriptionally inactivated by FOXA2 might contribute to the malignant progression of EC via the inhibition of ferroptosis.
ABSTRACT
Cardiovascular disease stemmed from atherosclerosis (AS) is well recognized to be the predominant cause of global death. To comprehensively clarify the pathogenesis of AS, exploit effective drugs, as well as develop therapeutic solutions, various atherosclerotic models were constructed in vitro and widely utilized by the scientific community. Compared with animal models, the in vitro atherosclerotic models play a prominent role not only in the targeted research of single pathological factor related to AS in the human derived system, but also in the combined study on multipathological factors leading to AS, thereby contributing tremendously to the in-depth elucidation of atherosclerotic pathological process. In the current review, a variety of pathological factors incorporated into the existing atherosclerotic models in vitro are broadly elaborated, including the pathological mechanism, in vitro simulation approaches, and the desired improvement perspectives for reproducing each pathological factor. In addition, this review also summarizes the advantages and disadvantages of current atherosclerotic models as well as their potential functionality. Finally, the promising aspects for future atherosclerotic models in vitro with potential advances are also discussed.
ABSTRACT
Electrochemical reduction of CO2 to highly valuable products is a promising way to reduce CO2 emissions. The shape and facets of metal nanocatalysts are the key parameters in determining the catalytic performance. However, the exposed crystal facets of ZnO with different morphologies and which facets achieve a high performance for CO2 reduction are still controversial. Here, we systematically investigate the effect of the facet-dependent reactivity of reduction of CO2 to CO on ZnO (nanowire, nanosheet, and flower-like). The ZnO nanosheet with exposed (110) facet exhibited prominent catalytic performance with a Faradaic efficiency of CO up to 84% and a current density of -10 mA cm-2 at -1.2 V versus RHE, far outperforming the ZnO nanowire (101) and ZnO nanoflower (103). Based on detailed characterizations and kinetic analysis, the ZnO nanosheet (110) with porous architecture increased the exposure of active sites. Further studies revealed that the high CO selectivity originated from the enhancement of CO2 adsorption and activation on the ZnO (110) facet, which promoted the conversion of CO2 toward CO. This study provides a new way to tailor the activity and selectivity of metal catalysts by engineering exposed specific facets.
ABSTRACT
Head and neck squamous cell carcinoma (HNSCC) is a significant cause of mortality, while the underlying mechanism remains unclear. Our studies have revealed that KIF2C plays a crucial role in tumor proliferation and metastasis in HNSCC. The results demonstrate that KIF2C is highly expressed at both the mRNA and protein levels and is closely associated with lymph node metastasis. The gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses indicate that the differentially expressed genes are enriched in processes or pathways related to cell adhesion and cell mitosis in HNSCC. Moreover, the established protein-protein interaction network identifies KIF2C as a potential hub gene in HNSCC. Knockdown of KIF2C has been demonstrated to significantly reduce cell migration and invasion ability, leading to cell cycle arrest, a high proportion of abnormal cell apoptosis, and cell chromosome division mismatches in the HNSCC cell line. Downstream genes such as PDGFA, EGFR, TP63, SNAI2, KRT5, and KRT14 were found to be down-regulated, and multiple critical pathways, including mTOR, ERK, and PI3K-AKT pathways, were inactivated as a result of KIF2C knockdown. These findings provide strong evidence for the crucial role of KIF2C in HNSCC and suggest that targeting KIF2C may be a promising therapeutic strategy for this disease. Knockdown of KIF2C has been shown to significantly inhibit tumor proliferation in nude mice, demonstrating the potential therapeutic role of KIF2C in HNSCC treatment.
ABSTRACT
Norcantharidin (NCTD) is a water-soluble synthetic small molecule drug that has been approved by the Chinese FDA for the treatment of cancer in China. Among these NCTD-treated cancers, hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide and one of the most extensively studied. Research over the past few decades has made great strides in understanding how NCTD induces mitotic arrest, anti-proliferation, anti-metastasis, apoptosis and cytotoxic autophagy or autophagic cell death in HCC. In this article, we review recent progress in the application of NCTD for the treatment of HCC, with emphasis on the pharmacological mechanism of NCTD against hepatocellular carcinoma. The accumulated results show that NCTD has the ability to induce mitotic arrest, anti-proliferation, anti-metastasis, apoptosis and cytotoxic autophagy or autophagic cell death in HCC by down-regulating the expression of ISG15, MMP-9, u-PA, Mcl-1 and the accumulation of regulatory T cells, up-regulating the expression of FAM46C, miR-214 and the expression and phosphorylation of p21Cip1/Waf1 and CDC25C, and by inhibiting the c-Met-mTOR and JAK/STAT3 signaling pathways, reversing the methylation of RASSF1A gene, and activating TRAIL-R2/DR5 signal transduction.
ABSTRACT
N6methyladenosine (m6A) serves an essential role in RNA modulation and is implicated in multiple malignancies, including colorectal cancer (CRC). Methyltransferaselike 3 (METTL3) is an important writer in m6A modification, however its role in CRC in modifying small nucleolar RNA host gene 1 (SNHG1), an oncogenic long noncoding RNA, remains unclear. In the present study, METTL3 expression in CRC was assessed using online bioinformatics analysis, immunohistochemistry staining, western blotting, reverse transcription (RT)quantitative PCR (qPCR) and cell transfections. Cell proliferation, migration and invasion were determined using functional Cell Counting Kit8 (CCK8) and Transwell assays. SNHG1 expression in CRC was evaluated using online bioinformatics analysis and RTqPCR. Methylated RNA immunoprecipitation qPCR was performed to assess m6A modification changes of SNHG1 mRNA. The present study demonstrated that METTL3 is upregulated in CRC tissues and cell lines. Moreover, METTL3 expression was associated with several unfavourable clinical features in patients with CRC, including the stage of lymph node metastases and overall survival. Functional Transwell and CCK8 assays demonstrated that knockdown of METTL3 suppressed CRC cell proliferation and migration. Furthermore, METTL3 was positively correlated with SNHG1 in CRC tissue, as indicated by analysis of data from The Cancer Genome Atlas. Mechanistically, SNHG1 contains 18 m6A modification sites. Through cell transfections and actinomycin D assays, the present study found that METTL3mediated m6A modification at these sites enhances the stability of SNHG1 in CRC cells. Finally, it was demonstrated that SNHG1 knockdown partially diminished the facilitative effect of METTL3 on CRC cell migration and proliferation. The present study concluded that METTL3, a potential biomarker for assessing overall survival and metastasis in CRC, may serve as an oncogene, promote SNHG1 m6A modification, improve the stability of SNHG1 and enhance SNHG1mediated oncogenic function in CRC.