Enhanced Sampling Molecular Dynamics Simulations Reveal Transport Mechanism of Glycoconjugate Drugs through GLUT1.

Glucose transporters GLUT1 belong to the major facilitator superfamily and are essential to human glucose uptake. The overexpression of GLUT1 in tumor cells designates it as a pivotal target for glycoconjugate anticancer drugs. However, the interaction mechanism of glycoconjugate drugs with GLUT1 remains largely unknown. Here, we employed all-atom molecular dynamics simulations, coupled to steered and umbrella sampling techniques, to examine the thermodynamics governing the transport of glucose and two glycoconjugate drugs (i.e., 6-D-glucose-conjugated methane sulfonate and 6-D-glucose chlorambucil) by GLUT1. We characterized the specific interactions between GLUT1 and substrates at different transport stages, including substrate recognition, transport, and releasing, and identified the key residues involved in these procedures. Importantly, our results described, for the first time, the free energy profiles of GLUT1-transporting glycoconjugate drugs, and demonstrated that H160 and W388 served as important gates to regulate their transport via GLUT1. These findings provide novel atomic-scale insights for understanding the transport mechanism of GLUT1, facilitating the discovery and rational design of GLUT1-targeted anticancer drugs.

Histone H2B lysine 122 and lysine 130, as the putative targets of Penicillium oxalicum LaeA, play important roles in asexual development, expression of secondary metabolite gene clusters, and extracellular glycoside hydrolase synthesis.

Core histones in the nucleosome are subject to a wide variety of posttranslational modifications (PTMs), such as methylation, phosphorylation, ubiquitylation, and acetylation, all of which are crucial in shaping the structure of the chromatin and the expression of the target genes. A putative histone methyltransferase LaeA/Lae1, which is conserved in numerous filamentous fungi, functions as a global regulator of fungal growth, virulence, secondary metabolite formation, and the production of extracellular glycoside hydrolases (GHs). LaeA's direct histone targets, however, were not yet recognized. Previous research has shown that LaeA interacts with core histone H2B. Using S-adenosyl-L-methionine (SAM) as a methyl group donor and recombinant human histone H2B as the substrate, it was found that Penicillium oxalicum LaeA can transfer the methyl groups to the C-terminal lysine (K) 108 and K116 residues in vitro. The H2BK108 and H2BK116 sites on recombinant histone correspond to P. oxalicum H2BK122 and H2BK130, respectively. H2BK122A and H2BK130A, two mutants with histone H2B K122 or K130 mutation to alanine (A), were constructed in P. oxalicum. The mutants H2BK122A and H2BK130A demonstrated altered asexual development and decreased extracellular GH production, consistent with the findings of the laeA gene deletion strain (ΔlaeA). The transcriptome data showed that when compared to wild-type (WT) of P. oxalicum, 38 of the 47 differentially expressed (fold change ≥ 2, FDR ≤ 0.05) genes that encode extracellular GHs showed the same expression pattern in the three mutants ΔlaeA, H2BK122A, and H2BK130A. The four secondary metabolic gene clusters that considerably decreased expression in ΔlaeA also significantly decreased in H2BK122A or H2BK130A. The chromatin of promotor regions of the key cellulolytic genes cel7A/cbh1 and cel7B/eg1 compacted in the ΔlaeA, H2BK122A, and H2BK130A mutants, according to the results of chromatin accessibility real-time PCR (CHART-PCR). The chromatin accessibility index dropped. The histone binding pocket of the LaeA-methyltransf_23 domain is compatible with particular histone H2B peptides, providing appropriate electrostatic and steric compatibility to stabilize these peptides, according to molecular docking. The findings of the study demonstrate that H2BK122 and H2BK130, which are histone targets of P. oxalicum LaeA in vitro, are crucial for fungal conidiation, the expression of gene clusters encoding secondary metabolites, and the production of extracellular GHs.

MicroRNA­30a­5p regulates cypermethrin-induced apoptosis of Sertoli cells by targeting KLF9 in vitro.

Cypermethrin (CYP) has been identified as one kind of endocrine-disrupting chemicals (EDCs) to induce male reproduction damage. This study aimed to investigate the effects and mechanisms of miR-30a-5p on CYP induced apoptosis of TM4 mouse Sertoli cells in vitro. In the present study, 0 µM, 10 µM, 20 µM, 40 µM and 80 µM CYP were used to treat TM4 cells for 24 h. The apoptosis of TM4 cells, the expression level of miR-30a-5p, the protein expressions and the interaction between miR-30a-5p and KLF9 were detected by flow cytometry, quantitative Real-Time PCR, Western blot and luciferase reporter assays. CYP induced apoptosis of TM4 cells, inhibited expression of miR-30a-5p in TM4 cells, and overexpression of miR-30a-5p partially recovered CYP induced cells apoptosis. Furthermore, KLF9 was a potential downstream target of miR-30a-5p predicted by publicly available databases. KLF9 expression level in TM4 cells was significantly elevated after treatment with CYP, and the induction was inhibited by miR-30a-5p mimics transfection. Meanwhile, dual-luciferase reporter assay demonstrated that miR-30a-5p directly targeted KLF9-3'UTR. Moreover, in the presence of CYP, the apoptosis regulator p53 expression was also increased in TM4 cells. Overexpression miR-30a-5p or down-regulation of KLF9 both attenuated the induction of CYP on p53 expression. Overall, the present study demonstrated that miR-30a-5p regulated CYP induced TM4 cells apoptosis by targeting KLF9/p53 axis.

BMP4 Regulates EMT to be Involved in non-Syndromic Cleft lip With or Without Palate.

OBJECTIVE: In the previous study, we identified bone morphogenetic protein 4 (BMP4) responsible for non-syndromic cleft lip with or without cleft palate (NSCL/P). We aimed to elucidate the effects and mechanisms of BMP4 on epithelial-mesenchymal transition (EMT) through Smad1 signaling pathway to be involved in NSCL/P. METHODS: The human oral epidermoid carcinoma cells (KBs) were transfected with plasmids or small interfering RNA (siRNA) to build the models. The migration of the cells was evaluated by transwell assay. Western blotting and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expressions of BMP4, E-cadherin, N-cadherin, EMT-related transcription factors snal1 and snal2, matrix metalloproteinase 2 (MMP2), MMP9, Smad1, and phosphorylated Smad1. RESULTS: In the overexpression group, the migration number of cells was increased significantly. The protein expression of E-cadherin was decreased significantly, while the protein expression level of the N-cadherin was increased significantly. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly higher. The expression level of Smad1 was not significantly changed, while the phosphorylation of Smad1 was significantly increased. In the BMP4-siRNA group, the migrating number cells was significantly decreased. The protein expression of E-cadherin was increased significantly, while the expression of N-cadherin was significantly decreased. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly lower than that of the control group. The expressions of Smad1 and phosphorylation of Smad1 were not significantly changed. CONCLUSIONS: BMP4 enhances cell migration and promotes cell EMT through Smad1 signaling pathway. Abnormal BMP4 mediates migration and EMT through other relevant signaling pathways resulting in NSCL/P. The study provides new insight into the mechanisms of NSCL/P associated with BMP4.n.

Abnormalities of hsa-mir-16 and hsa-mir-124 Affect Mitochondrial Function and Fatty Acid Metabolism in Tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease in clinical practice. It is mainly due to cardiovascular hypoplasia during embryonic development. The study aimed to find the etiology of TOF. METHODS: Through the mRNA expression profile analysis of the GSE35776 dataset, differentially expressed genes (DEGs) were found, and the functional analysis and protein-protein interaction (PPI) network analysis were then performed on DEGs. Likewise, the hub genes and functional clusters of DEGs were analyzed using the PPI network. Differentially expressed miRNAs were analyzed from the GSE35490 dataset, followed by miRNet predicted transcription factors (TFs) and target genes. The key TF-miRNA-gene interaction mechanism was explored through the found significant difference between genes and target genes. RESULTS: A total of 191 differentially expressed genes and 57 differentially expressed miRNAs were identified. The main mechanisms involved in TOF were mitochondria-related and energy metabolism- related molecules and pathways in GO and KEGG analysis. This discovery was identical in TFs and target genes. The key miRNAs, hsa-mir-16 and hsa-mir-124, were discovered by the Venn diagram. A co-expression network with the mechanism of action centered on two miRNAs was made. CONCLUSION: Hsa-mir-16 and hsa-mir-124 are the key miRNAs of TOF, which mainly regulate the expression of NT5DC1, ECHDC1, HSDL2, FCHO2, and ACAA2 involved in the conversion of ATP in the mitochondria and the metabolic rate of fatty acids (FA). Our research provides key molecules and pathways into the etiology of TOF, which can be used as therapeutic targets.

Modulating insulin signaling and trafficking at the blood-brain barrier endothelium using lipid based nanoemulsions.

The compositionally distinct lipid rafts present in the plasma membrane regulate the restrictive trafficking and signal transduction in the blood-brain barrier (BBB) endothelium. Several metabolic and neurodegenerative diseases are associated with lipid homeostasis disruption within the BBB endothelium. Here, we hypothesized that the delivery of lipid triglyceride based nanoemulsions containing unsaturated fatty acids (UFAs) provides a novel non-pharmacological approach to modulate lipid raft integrity and rectify the aberrant trafficking and signal transduction. The current study has shown that soybean oil nanoemulsions (SNEs) altered the morphology of lipid rafts that are stained by Alex Fluor 647 labelled cholera toxin (AF647-CTX) in polarized human cerebral microvascular endothelial (hCMEC/D3) cell monolayers. Moreover, western blot and flow cytometry analysis showed that SNEs containing polyunsaturated fatty acids (PUFAs) increased phospo-AKT (p-AKT) expression, a marker for the stimulation of metabolic arm of insulin signaling, and insulin uptake in hCMEC/D3 monolayers. However, olive oil nanoemulsions (ONEs) containing monounsaturated fatty acids (MUFAs) had no detectable impact on lipid raft integrity, AKT phosphorylation, or insulin uptake. These findings provided direct evidence that SNEs containing PUFAs can upregulate insulin-pAKT pathway, facilitate insulin trafficking at the BBB, and potentially address cerebrovascular dysfunction in metabolic and neurodegenerative diseases.

Production of microhomogeneous glycopeptide by a mutated NGT according FuncLib with unique sugar as substrate.

N-glycosylation is one of the most important post-translational modifications of proteins. Cytoplasmic soluble N-glycosyltransferase (NGT) exists in bacteria, which is able to transfer different monosaccharide from sugar nucleotide to the NXS/T(X ≠ Pro) consensus sequence in a polypeptide. At present, the NGT enzymes reported could transfer a variety of different sugars to protein, which will lead to the heterogeneity of the sugar chain and the complexity and instability of the structure and function of glycopeptides. According to the FuncLib algorithm, we obtained mutant ApNGT-P1 from ApNGT (the NGT from Actinobacillus pleuropneumoniae) with increased substrate specificity. Compared with the wild-type ApNGT, mutant ApNGT-P1 could only utilize UDP-Glc as sugar donors. The optimum temperature of ApNGT-P1 was about 40 °C and the optimum pH was 7.5-8.0 in PBS buffer. ApNGT-P1 exhibited better tolerance for K+, Mn2+, Ca2+, and Mg2+, but was strongly inhibited by Na+, Cu2+ and Zn2+. The mutant can be applied to the efficient production of glycosylated peptides or proteins with uniform glucose at their glycosylation sites. Besides, this work provided a feasible pathway for further studies on the improving donor substrates selectivity of NGTs.

Cypermethrin induces Sertoli cell apoptosis through mitochondrial pathway associated with calcium.

Cypermethrin, one kind of pyrethroid pesticides, has been shown to act as endocrine-disrupting chemicals (EDCs). The purpose of this study was to explore the roles of Sertoli cell apoptosis through mitochondrial pathway associated with calcium (Ca2+) in cypermethrin-induced male reproductive toxicology. The mouse Sertoli cells TM4 were cultured with 0 µM, 10 µM, 20 µM, 40 µM and 80 µM of cypermethrin. We used flow cytometry, Fluo-4 AM, western blot and JC-1 Assay Kit to examine apoptosis, intracellular Ca2+, expressions of mitochondrial apoptotic pathway-related proteins and mitochondrial membrane potential. We found cypermethrin increased apoptosis rate of TM4 cells significantly and with a significant increase in intracellular Ca2+ concentration. Cypermethrin significantly decreased the protein expressions of cytosolic B-cell lymphoma-2 (Bcl-2) and mitochondrial cytochrome c (Cyt-c). The protein expressions of cytosolic Bcl-2-associated x (Bax), Cyt-c, cleaved caspase-3, calmodulin (CaM), Ca2+/CaM-dependent protein kinases II (CaMKII) and phosphorylated CaMKII were increased significantly in cypermethrin-exposed TM4 cells. Cypermethrin decreased mitochondrial membrane potential significantly. Then, Bcl-2 family and Ca2+/CaM/CaMKII pathway participate in cypermethrin-induced homeostasis. Ca2+ overload activates mitochondrial pathway by increasing permeability of mitochondrial membrane and decreasing mitochondrial membrane potential. We suggest cypermethrin induces Sertoli cell apoptosis involving mitochondrial pathway associated with Ca2+ regulated by Bcl-2 family and Ca2+/CaM/CaMKII pathway. The study provides a new insight into mechanisms involved in cypermethrin-induced male reproductive toxicology.

A highly efficient protein degradation system in Bacillus sp. CN2: a functional-degradomics study.

A novel protease-producing Bacillus sp. CN2 isolated from chicken manure composts exhibited a relatively high proteolytic specific activity. The strain CN2 degradome consisted of at least 149 proteases and homolog candidates, which were distributed into 4 aspartic, 30 cysteine, 55 metallo, 56 serine, and 4 threonine proteases. Extracellular proteolytic activity was almost completely inhibited by PMSF (phenylmethylsulfonyl fluoride) rather than o-P, E-64, or pepstatin A, suggesting that strain CN2 primarily secreted serine protease. More importantly, analysis of the extracellular proteome of strain CN2 revealed the presence of a highly efficient protein degradation system. Three serine proteases of the S8 family with different active site architectures firstly fragmented protein substrates which were then degraded to smaller peptides by a M4 metalloendopeptidase that prefers to degrade hydrophobic peptides and by a S13 carboxypeptidase. Those enzymes acted synergistically to degrade intact substrate proteins outside the cell. Furthermore, highly expressed sequence-specific intracellular aminopeptidases from multiple families (M20, M29, and M42) accurately degraded peptides into oligopeptides or amino acids, thus realizing the rapid acquisition and utilization of nitrogen sources. In this paper, a systematic study of the functional-degradome provided a new perspective for understanding the complexity of the protease hydrolysis system of Bacillus, and laid a solid foundation for further studying the precise degradation of proteins with the cooperative action of different family proteases. KEY POINTS: • Bacillus sp. CN2 has relatively high proteolytic specific activity. • Bacillus sp. CN2 harbors a highly efficient protein degradation system. • The site-specific endopeptidases were secreted extracellular, while the sequence-specific aminopeptidases played a role in the cell.

Effects of small interfering RNA-mediated silencing of susceptibility genes of non-syndromic cleft lip with or without cleft palate on cell proliferation and migration.

BACKGROUND: Non-syndrome cleft lip with or without cleft palate (NSCL/P) is the most common congenital defect with a complex etiology involving both genetic and environmental factors. Our previous research has identified susceptibility genes of NSCL/P using whole-exome sequencing. The study was to determine the effects of small interfering RNA (siRNA)-mediated silencing of genes on cell proliferation and migration to confirm the roles of the genes in NSCL/P. METHODS: We silenced the genes by RNA interference (RNAi) with siRNA in human oral keratinocyte (HOK). We used the Cell Counting Kit-8 (CCK8) assay to determine cell proliferation and the wound healing assay to determine cell migration. RESULTS: Migration of HOK was inhibited by RNAi-induced silencing of adenosine triphosphate binding cassette transporter A4 (ABCA4), erythropoietin produces hepatocyte A receptor 3 (EPHA3), alpha-parvin (PARVA), and platelet-derived growth factor C (PDGFC). The change of proliferation was not found. Treated with siRNA-mediated silencing of type IV collagen (COL4A2), eukaryotic translation initiation factor 2B subunit (EIF2B3), fibroblast growth factor receptor 2 (FGFR2), kinesin family member 20B (KIF20B), ß-lactamase serine-like protein (LACTB), SEC16 homolog A (SEC16A) and thyroid adenoma target gene (THADA) had no effects on cell proliferation and migration of HOK. CONCLUSIONS: We suggest mutations of the four susceptibility genes ABCA4, EPHA3, PARVA and PDGFC are involved in NSCL/P through inhibiting cell migration. The study provides new candidates for future study of NSCL/P.

Penicillium oxalicum putative methyltransferase Mtr23B has similarities and differences with LaeA in regulating conidium development and glycoside hydrolase gene expression.

Putative methyltranferase LaeA and LaeA-like proteins, which are conserved in many filamentous fungi, regulate the sporogenesis and biosynthesis of secondary metabolites. In this study, we reported the biological function of a LaeA-like methyltransferase, Penicillium oxalicum Mtr23B, which contains a methyltransf_23 domain and an S-adenosylmethionine binding domain, in controlling spore pigment formation and in the expression of secondary metabolic gene cluster and glycoside hydrolase genes. Additionally, we compared Mtr23B and LaeA, and determined their similarities and differences in terms of their roles in regulating the above biological processes. mtr23B had the highest transcriptional level among the 12 members of the methyltransf_23 family in P. oxalicum. The colony color of Δmtr23B (deletion of mtr23B) was lighter than that of ΔlaeA, although Δmtr23B produced ~ 19.2-fold more conidia than ΔlaeA. The transcriptional levels of abrA, abrB/yA, albA/wA, arpA, arpB, and aygA, which are involved in the dihydroxynaphtalene-melanin pathway, decreased in Δmtr23B. However, Mtr23B had a little effect on brush-like structures and conidium formation, and had a different function from LaeA. Mtr23B extensively regulated glycoside hydrolase gene expression. The absence of Mtr23B remarkably repressed prominent cellulase- and amylase-encoding genes in the whole culture period, while the effect of LaeA mainly occurred in the later phases of prolonged batch cultures. Similar to LaeA, Mtr23B was involved in the expression of 10 physically linked regions containing secondary metabolic gene clusters; the highest regulatory activities of Mtr23B and LaeA were observed in BrlA-dependent cascades. Although LaeA interacted with VeA, Mtr23B did not interact with VeA directly. We assumed that Mtr23B regulates cellulase and amylase gene transcription by interacting with the CCAAT-binding transcription factor HAP5 and chromatin remodeling complex.

Structure-Interaction Relationship of Polymyxins with the Membrane of Human Kidney Proximal Tubular Cells.

Multidrug-resistant Gram-negative bacteria are a serious global threat to human health. Polymyxins are increasingly used in patients as a last-line therapy to treat infections caused by these life-threatening 'superbugs'. Unfortunately, polymyxin-induced nephrotoxicity is the major dose-limiting factor and understanding its mechanism is crucial for the development of novel, safer polymyxins. Here, we undertook the first all-atom molecular dynamics simulations of the interaction between four naturally occurring polymyxins A1, B1, M1 and colistin A (representative structural variations of the polymyxin core structure) and the membrane of human kidney proximal tubular cells. All polymyxins inserted spontaneously into the hydrophobic region of the membrane where they were retained, although their insertion abilities varied. Polymyxin A1 completely penetrated into the hydrophobic region of the membrane with a unique folded conformation, whereas the other three polymyxins only inserted their fatty acyl tails into this region. Furthermore, local membrane defects and increased water penetration were induced by each polymyxin, which may represent the initial stage of cellular membrane damage. Finally, the structure-interaction relationship of polymyxins was investigated based on atomic interactions at the cell membrane level. The hydrophobicity at positions 6/7 and stereochemistry at position 3 regulated the interactions of polymyxins with the cell membrane. Collectively, our results provide new mechanistic insights into polymyxin-induced nephrotoxicity at the atomic level and will facilitate the development of new-generation polymyxins.

TGFß regulates NK1R-Tr to affect the proliferation and apoptosis of breast cancer cells.

OBJECTIVES: TGFß promotes cancer aggressiveness in advanced stages. NK1R-Tr expression in advanced breast cancer has a pro-carcinogenic effect. In this study, we aimed to investigate the effect of the association of TGFß with NK1R-Tr expression on the proliferation and apoptosis of breast cancer cells. METHODS: Immunohistochemical staining and Western blot analysis were used to detect TGFß and NK1R-Tr in breast cancer and paracancerous tissue samples. MDA-MB-231 and BT549 cells were stimulated with TGFß after NK1R knockdown or treated with the NK1R antagonist aprepitant, and the effects of TGFß and NK1R-Tr on proliferation and apoptosis were detected by CCK-8, colony formation and flow cytometry assays. In vivo xenograft models were used to further verify the effects of NK1R-Tr and TGFß. The regulatory effects of Smad4 on NK1R promoter activity were confirmed by ChIP and dual-luciferase reporter assays. RESULTS: The expression levels of TGFß and NK1R-Tr were higher in breast cancer tissues than in adjacent tissues and were positively correlated in human breast cancer tissues. NK1R knockdown or aprepitant treatment in MDA-MB-231 and BT549 cells attenuated the effects of TGFß on cell proliferation. The proportion of cells in G2/M phase significantly increased, the expression of cyclin B1 decreased, and the expression of P21 increased; these effects were weakened by TGFß treatment. Apoptosis in breast cancer cells was significantly increased. In vivo xenograft models were used to further verify that NK1R-Tr and TGFß promoted tumour growth. After TGFß treatment, the binding capacity of Smad4 to the NK1R promoter, as well as luciferase activity, was enhanced. CONCLUSIONS: The expression levels of TGFß and NK1R-Tr were higher in breast cancer tissues than in normal tissues, and both were correlated with a poor patient prognosis. TGFß and NK1R-Tr promoted cell proliferation and inhibited apoptosis, and TGFß regulated the expression of NK1R-Tr via Smad4.

New sesquiterpenoid glycoside from the rhizomes of Atractylodes lancea.

Six sesquiterpenoids and four lignans (1-10) were isolated from the n-BuOH extract of the rhizomes of Atractylodes lancea. Among them, the new sesquiterpenoid glycoside named (4 R, 5S, 7R)-hinesolone-11-O-ß-ᴅ-glucopyranoside (1), along with three known compounds (2-4) were first obtained from this genus. All the isolates were elucidated by spectroscopic analyses and chemical methods, and the absolute configurations were assigned by electronic circular dichroism spectroscopy technique. In addition, the cytotoxic bioassay of compound 1 was evaluated and results showed it had no significant antitumor activity against human cancer cell lines MCF-7, HepG-2 and Hela.

Prediction of Driver Modules via Balancing Exclusive Coverages of Mutations in Cancer Samples.

Mutual exclusivity of cancer driving mutations is a frequently observed phenomenon in the mutational landscape of cancer. The long tail of rare mutations complicates the discovery of mutually exclusive driver modules. The existing methods usually suffer from the problem that only few genes in some identified modules cover most of the cancer samples. To overcome this hurdle, an efficient method UniCovEx is presented via identifying mutually exclusive driver modules of balanced exclusive coverages. UniCovEx first searches for candidate driver modules with a strong topological relationship in signaling networks using a greedy strategy. It then evaluates the candidate modules by considering their coverage, exclusivity, and balance of coverage, using a novel metric termed exclusive entropy of modules, which measures how balanced the modules are. Finally, UniCovEx predicts sample-specific driver modules by solving a minimum set cover problem using a greedy strategy. When tested on 12 The Cancer Genome Atlas datasets of different cancer types, UniCovEx shows a significant superiority over the previous methods. The software is available at: https://sourceforge.net/projects/cancer-pathway/files/.

MiR-34b/c-5p and the neurokinin-1 receptor regulate breast cancer cell proliferation and apoptosis.

OBJECTIVES: MiR-34 is a tumour suppressor in breast cancer. Neurokinin-1 receptor (NK1R), which is the predicted target of the miR-34 family, is overexpressed in many cancers. This study investigated the correlation and clinical significance of miR-34 and NK1R in breast cancer. MATERIALS AND METHODS: Western blotting, quantitative reverse transcription-PCR (qRT-PCR) and luciferase assays were conducted to analyse the regulation of NK1R by miR-34 in MDA-MB-231, MCF-7, T47D, SK-BR-3 and HEK-293 T cells. MiR-34b/c-5p, full-length NK1R (NK1R-FL) and truncated NK1R (NK1R-Tr) expression in fifty patients were quantified by qRT-PCR and correlated with their clinicopathological parameters. CCK-8 assays, colony formation assays and flow cytometry were used to measure cell proliferation and apoptosis in MDA-MB-231 and MCF-7 cells transfected with miR-34b/c-5p or NK1R-siRNA and before treatment with or without Substance P (SP), an endogenous peptide agonists of NK1R. The effect of NK1R antagonist aprepitant was also investigated. In vivo xenograft models were used to further verify the regulation of NK1R by miR-34b/c-5p. RESULTS: Expression levels of miR-34b/c-5p and NK1R-Tr, but not NK1R-FL, were associated with enhanced malignant potential, such as tumour stage and Ki67 expression. The overexpression of miR-34b/c-5p or NK1R silencing potently suppressed cell proliferation and induced G2/M phase arrest and the apoptosis of MDA-MB-231 and MCF-7 cells. The NK1R antagonist aprepitant had similar effects. In vivo studies confirmed that miR-34b/c-5p overexpression or NK1R silencing reduced the tumorigenicity of breast cancer. In addition, SP rescued the effects of miR-34b/c-5p overexpression or NK1R silencing on cell proliferation and apoptosis in vitro and in vivo assays. CONCLUSIONS: MiR-34b/c-5p and NK1R contribute to breast cancer cell proliferation and apoptosis and are potential targets for breast cancer therapeutics.

Baicalein inhibits osteosarcoma cell proliferation and invasion through the miR­183/Ezrin pathway.

Osteosarcoma (OS), a common and primary malignant bone tumor, is characterized by highly aggressive potency. Baicalein, a bioactive flavone isolated from Scutellaria baicalensis Georgi, has been shown to inhibit the progression of numerous tumors, including OS. However, the mechanisms by which baicalein protects against OS are still largely unknown. The results of the present study showed that administration of baicalein significantly inhibited the proliferation, migration and invasion and promoted apoptosis in MG­63 and Saos­2 cells. Ezrin was identified as a target gene of microRNA (miR)­183. MG­63 and Saos­2 cells treated with baicalein exhibited increased miR­183 levels and decreased Ezrin expression. Importantly, miR­183 inhibition and Ezrin overexpression abolished the effects of baicalein on MG­63 and Saos­2 cell proliferation, migration, invasion and apoptosis. Taken together, these findings suggest that baicalein inhibits the proliferation, migration and invasion and induces apoptosis in OS cells by activating the miR­183/Ezrin pathway, revealing a novel mechanism underlying anti­OS effects of baicalein.

Environmental Adaptability and Quorum Sensing: Iron Uptake Regulation during Biofilm Formation by Paracoccus denitrificans.

Paracoccus denitrificans is a valuable model organism due to its versatile respiration capability and bioenergetic flexibility, both of which are critical to its survival in different environments. Quorum sensing (QS) plays a crucial role in the regulation of many cell functions; however, whether QS systems play a role in P. denitrificans is unknown. In this study, we demonstrated that iron uptake systems in P. denitrificans were directly regulated by a newly identified QS system. Genes coding for TonB-dependent systems, which transport chelated iron, were transcribed at higher levels in the QS-defective mutants. In contrast, genes coding for the Fbp system, which is TonB independent and transports unchelated ferric iron, were downregulated in the mutants. In brief, QS in P. denitrificans triggers a switch in iron uptake from TonB-dependent to TonB-independent transport during biofilm formation as higher concentrations of iron accumulate in the exopolysaccharide (EPS). Switching from TonB-dependent iron uptake systems to TonB-independent systems not only prevents cells from absorbing excess iron but also conserves energy. Our data suggest that iron uptake strategies are directly regulated by QS in Paracoccus denitrificans to support their survival in available ecological niches.IMPORTANCE As iron is an important trace metal for most organisms, its absorption is highly regulated. Fur has been reported as a prevalent regulator of iron acquisition. In addition, there is a relationship between QS and iron acquisition in pathogenic microbes. However, there have been few studies on the iron uptake strategies of nonpathogenic bacteria. In this study, we demonstrated that iron uptake systems in Paracoccus denitrificans PD1222 were regulated by a newly identified PdeR/PdeI QS system during biofilm formation, and we put forward a hypothesis that QS-dependent iron uptake systems benefit the stability of biofilms. This report elaborates the correlation among QS, iron uptake, and biofilm formation and thus contributes to an understanding of the ecological behavior of environmental bacteria.

[Effects of electroacupuncture on electrocardiogram, myocardial pathological morphology and PI3K/Akt pathway in rats with chronic myocardial ischemia].

OBJECTIVE: To explore the effects of principal-subordinate acupoints combination on improving myocardial ischemia, and the gene regulatory pathways for the protection of myocardial ischemia. METHODS: According to the random number table method, 70 SPF Wistar male rats were divided into a normal group, a model group, a LY294002 group, an insulin-like growth factors-1(IGF-1) group, a Neiguan group, an acupoint combination group and an acupoint combination + LY294002 group, 10 rats in each one. Rats in the normal group were injected with 0.9% NaCl solution, while rats in the remaining groups were treated with abdominal subcutaneous injection of isoroterenol hydrochloride to establish the rat model of myocardial ischemia. Rats in the LY294002 group and IGF-1 group were treated with injection of LY294002 solution and IGF-1 solution for 14 days. Rats in the Neiguan group were treated with electroacupuncture (EA) at "Neiguan" (PC 6) by using Han-200 EA apparatus for 10 min per treatment. Rats in the acupoint combination group were treated with EA at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) by using Han-200 EA apparatus for 10 min per treatment. Rats in the acupoint combination + LY294002 group were treated with LY294002 solution for 14 days, and EA at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) was given before model establishment, once a day for 21 days. EA pretreatment was given before model establishment in all acupuncture groups. The heart rate (HR) and ST segment voltage were detected before and after treatment; the myocardial pathological morphology was observed by HE staining; the expressions of P13K mRNA and Akt mRNA were tested. RESULTS: After modeling, HR and ST segment voltage in all intervention groups were higher than those in the normal group (all P < 0.01); after the intervention, the HR and the ST segment voltage in the acupoint combination group, IGF-1 group and IGF-1 group were improved (P < 0.01, P < 0.05), which was more significant in the acupoint combination group and Neiguan group (all P < 0.01). As for the myocardial pathological morphology, obvious myocardial ischemia was observed in the model group, and that in the LY294002 group was the most serious, and that in the acupoint combination+ LY294002 group was moderate. After intervention, the myocardial pathological damage in the IGF-1 group, Neiguan group and acupoint combination group was significant improved, which was more significant in the IGF-1 group and acupoint combination group. As for the expression of PI3K mRNA and Akt mRNA, compared with normal group, the expression of PI3K mRNA was increased in the remaining groups after modeling (P < 0.01, P < 0.05), which was more significant in the IGF-1 group and acupoint combination group (all P < 0. 01). The expression of Akt mRNA in the LY294002 group and acupoint combination + LY294002 group was reduced (P < 0. 01, P < 0.05), while that in the remaining groups was increased (P < 0.01, P < 0.05), which was more significant in the IGF-1 group and acupoint combination group (all P < 0.01). CONCLUSION: The principal-subordinate acupoints combination could improve heart rate and ST segment voltage in rats with chronic myocardial ischemia, reduce myocardial pathological damage, which is superior to single selection of "Neiguan" (PC 6). The PI3K/Akt signaling pathway may be involved in the regulation mechanism of principal-subordinate acupoints combination for the protection of chronic myocardial ischemia.

Long-term effects of acupuncture treatment on airway smooth muscle in a rat model of smoke-induced chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. It is a chronic inflammatory process characterised by airway obstruction and progressive lung inflammation, associated with difficulty breathing and insensitivity to corticosteroid therapy. Although there is some preliminary evidence to suggest a beneficial effect of acupuncture on COPD, its mechanism of action has not been investigated. Our aim was to examine the anti-inflammatory effects of acupuncture in a rat model of COPD induced by exposure to cigarette smoke (CS). METHODS: Sixty Sprague-Dawley rats were exposed to the smoke of 15 cigarettes for 1 h/day, 6 days/week for 3 months to induce COPD and treated with acupuncture at BL13 (Feishu), BL23 (Shenshu) and Dingchuan (COPD+Acupuncture, n=15), sham acupuncture (COPD+Sham, n=15) or left untreated (n=15). Exposed rats were compared with controls not exposed to CS (control, n=15). Pulmonary function was measured, and tumour necrosis factor-α (TNF-α) and interleukin-8 (IL-8) levels were determined in bronchoalveolar lavage fluid by ELISA. Histone deacetylase 2 (HDAC2) protein and mRNA expression were examined in lung tissue and in bronchus. RESULTS: Acupuncture treatment appeared to protect pulmonary function and reduce the COPD-induced inflammatory response by decreasing cell inflammation and the production of TNF-α and IL-8. Acupuncture also enhanced HDAC2 mRNA and protein expression, suggesting a possible direct effect on protein structure through post-translational modifications. CONCLUSIONS: Our results suggest that acupuncture regulates inflammatory cytokines and contributes to lung protection in a rat model of smoke-induced COPD by modulating HDAC2.