Chronic CSE Treatment Induces the Growth of Normal Oral Keratinocytes via PDK2 Upregulation, Increased Glycolysis and HIF1α Stabilization

Exposure to cigarette smoke is a major risk factor for head and neck squamous cell carcinoma (HNSCC). We have previously established a chronic cigarette smoke extract (CSE)-treated human oral normal keratinocyte model, demonstrating an elevated frequency of mitochondrial mutations in CSE treated cells. Using this model we further characterized the mechanism by which chronic CSE treatment induces increased cellular proliferation.We demonstrate that chronic CSE treatment upregulates PDK2 expression, decreases PDH activity and thereby increases the glycolytic metabolites pyruvate and lactate. We also found that the chronic CSE treatment enhanced HIF1α accumulation through increased pyruvate and lactate production in a manner selectively reversible by ascorbate. Use of a HIF1α small molecule inhibitor blocked the growth induced by chronic CSE treatment in OKF6 cells. Furthermore, chronic CSE treatment was found to increase ROS (reactive oxygen species) production, and application of the ROS scavengers N-acetylcysteine abrogated the expression of PDK2 and HIF1α. Notably, treatment with dichloroacetate, a PDK2 inhibitor, also decreased the HIF1α expression as well as cell proliferation in chronic CSE treated OKF6 cells.Our findings suggest that chronic CSE treatment contribute to cell growth via increased ROS production through mitochondrial mutations, upregulation of PDK2, attenuating PDH activity thereby increasing glycolytic metabolites, resulting in HIF1α stabilization. This study suggests a role for chronic tobacco exposure in the development of aerobic glycolysis and normoxic HIFα activation as a part of HNSCC initiation. These data may provide insights into development of chemopreventive strategies for smoking related cancers

Needle δ13C and mobile carbohydrates in Pinus koraiensis in relation to decreased temperature and increased moisture along an elevational gradient in NE China

A tree's crown interacts with atmospheric variables such as CO2, temperature, and humidity. Physioecology of leaves/needles (e.g. δ13C, mobile carbohydrates, and nitrogen) is, therefore, strongly affected by microclimate in and surrounding a tree crown. To understand the physiological responses of leaves to changes in air temperature and moisture, we measured δ13C, soluble sugars, starch, and total nitrogen (N) concentrations in current year and 1-yr-old needles of Pinus koraiensis trees, and compared the growing season air temperature and relative humidity within and outside P. koraiensis crowns along an elevational gradient from 760 to 1,420ma.s.l. on Changbai Mountain, NE China. Our results indicated that needle N and mobile carbohydrates concentrations, as well as needle δ13C values changed continuously with increasing elevation, corresponding to a continuous decrease in air temperature and an increase in relative humidity. Needle carbon and nitrogen status is highly significantly negatively correlated with temperature, but positively correlated with relative humidity. These results indicate that increases in air temperature in combination with decreases in relative humidity may result in lower levels of N and mobile carbohydrates in P. koraiensis trees, suggesting that future climate changes such as global warming and changes in precipitation patterns will directly influence the N and carbon physiology at P. koraiensis individual level, and indirectly affect the competitive ability, species composition, productivity and functioning at the stand and ecosystem level in NE China. Due to the relatively limited range of the transect (760-1,420m) studied, further research is needed to explain whether the present results are applicable to scales across large elevational gradient

Synthesis and volume phase transition of concanavalin A-based glucose-responsive nanogels

NSFC [21274118, 91227120, 20923004]; FRFCU [2012121016]; NFFTBS [J1210014]; NCETFJGlucose-responsive polymer nanogels that can undergo a reversible and rapid volume phase transition in response to the fluctuation in blood glucose concentration have the potential to regulate the delivery of insulin mimicking pancreatic activity. We report here such a glucose-responsive polymer nanogel, which is made of concanavalin A (ConA) interpenetrated in a chemically crosslinked network of poly(N-isopropylacrylamide) (poly(NIPAM)). The introduction of ConA, a plant lectin protein, into the poly(NIPAM) network makes the newly developed semi-interpenetrating-structured nanogels responsive to glucose over a glucose concentration range of 0-20 mM at a physiological pH of 7.4. While the nanogels can swell and become stable shortly (<1 s) after adding glucose over a concentration range of 50.0 mu M to 20.0 mM, the changes in the average hydrodynamic radius and the size distribution of the nanogels can be fully reversible within the experimental error even after ten cycles of adding/removing glucose. The association rate constant is determined to be ca. 1.8 mM(-1) s(-1), and the dissociation rate constant is ca. 7.5 s(-1), indicating a fast reversible time response to the glucose concentration change of the nanogels. Moreover, in vitro insulin release can be modulated in a pulsatile profile in response to glucose concentrations

Cross-inhibition to heterologous foot-and-mouth disease virus infection induced by RNA interference targeting the conserved regions of viral genome

AbstractRNA interference (RNAi) is the process by which double-stranded RNA (dsRNA) directs sequence-specific degradation of messenger RNA in animal and plant cells. In mammalian cells, RNAi can be triggered by 21–23 nucleotide duplexes of small interfering RNA (siRNA). Strategies to inhibit RNA virus multiplication based on the use of siRNAs have to consider the high genetic polymorphism exhibited by this group of virus. Here we described a significant cross-inhibition of foot-and-mouth disease (FMD) virus (FMDV) replication in BHK-21 cells by siRNAs targeted to various conserved regions (5′NCR, VP4, VPg, POL, and 3′NCR) of the viral genome. The results showed that siRNAs generated in vitro by human recombinant dicer enzyme gave an inhibition of 10- to 1000-fold in virus yield of both homologous (HKN/2002) and heterologous (CHA/99) isolates of FMDV serotype O at 48 h post-infection (hpi). The inhibition extended to at least 6 days post-infection. For serotype Asia1, the virus yield in YNBS/58-infected cells examined at 12, 24, and 48 hpi decreased by ∼10-fold in cells pretreated with HKN/2002-specific siRNAs, but there was no significant decrease at 60 hpi. The inhibition was specific to FMDV replication, as no reduction was observed in virus yield of pseudorabies virus, an unrelated virus. Moreover, we also demonstrated an enhanced viral suppression could be achieved in BHK-21 cells with siRNA transfection after an infection had been established. These results suggested that siRNAs directed to several conserved regions of the FMDV genome could inhibit FMDV replication in a cross-resistance manner, providing a strategy candidate to treat high genetic variability of FMDV

Circulating miRNA Expression Profiling and Target Prediction in Patients Receiving Dexmedetomidine

Background/Aims: Circulating miRNAs could serve as biomarkers for diagnosis or prognosis of heart diseases and cerebrovascular diseases. Dexmedetomidine has protective effects in various organs. The effects of dexmedetomidine on circulating miRNAs remain unknown. Here, we investigated differentially expressed miRNA and to predict the target genes of the miRNA in patients receiving dexmedetomidine. Methods: The expression levels of circulating miRNAs of 3 patients were determined through high through-put miRNA sequencing technology. Target genes of the identified differentially expressed miRNAs were predicted using TargetScan 7.1 and miRDB v.5. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to conduct functional annotation and pathway enrichment analysis of target genes respectively. Results: Twelve differentially expressed miRNAs were identified. Five miRNAs were upregulated (hsa-miR-4508, hsa-miR-novel-chr8_87373, hsa-miR-30a-3p, hsa-miR-novel-chr16_26099, hsa-miR-4306) and seven miRNAs (hsa-miR-744-5p, hsa-miR-320a, hsa-miR-novel-chr9_90035, hsa-miR-101-3p, hsa-miR-150-5p, hsa-miR-342-3p, and hsa-miR-140-3p) were downregulated after administration of dexmedetomidine in the subjects. The target genes and pathways related to the differentially expressed miRNAs were predicted and analyzed. Conclusion: The differentially expressed miRNAs may be involved in the mechanisms of action of dexmedetomidine. Specific miRNAs, such as hsa-miR-101-3p, hsa-miR-150-5p and hsa-miR-140-3p, are new potential targets for further functional studies of dexmedetomidine

A Neuroimaging Marker Based on Diffusion Tensor Imaging and Cognitive Impairment Due to Cerebral White Matter Lesions

Background: The peak width of skeletonized mean diffusivity (PSMD) is a new, fully automated, robust imaging marker for cerebral small vessel disease (SVD), strongly associated with processing speed. However, it has never been applied to cerebral white matter lesions (WMLs). Our study aimed to investigate the correlation between PSMD and cognition, particularly in the executive function of patients with WMLs.Methods: A total of 111 WML patients and 50 healthy controls (HCs) were enrolled, and their demographic information and cardiovascular disease risk factors were recorded. Subjects were divided into three groups: WMLs with normal cognition (WMLs-NC), WMLs with vascular cognitive impairment (WMLs-VCI), and HCs. They underwent conventional head magnetic resonance imaging and diffusion tensor imaging (DTI), followed by neuropsychological and psychological examinations, including the Montreal Cognitive Assessment (MoCA), and the executive function tests. We compared executive function and PSMD among the three groups and analyzed the correlation between PSMD and cognitive function in all subjects.Results: There were no significant differences in demographic characteristics (age, sex, education level, and cardiovascular disease risk factors) among the three groups (P &gt; 0.05), but there were significant differences in global cognition (P &lt; 0.0001), executive function (P &lt; 0.0001), and PSMD (P &lt; 0.0001). The average PSMD value (×10−4 mm2/s) was 2.40 ± 0.23, 2.68 ± 0.30, and 4.51 ± 0.39 in the HC, WMLs-NC, and WMLs-VCI groups, respectively. There was no correlation between PSMD and cognition in the HC group, but PSMD was significantly correlated with MoCA scores (r = −0.3785, P &lt; 0.0001) and executive function (r = −0.4744, P &lt; 0.0001) in the WMLs-NC group and in the WMLs-VCI group (r = −0.4448, P &lt; 0.0001 and r = −0.6279, P &lt; 0.0001, respectively).Conclusions: WML patients have higher PSMD and worse cognitive performance than HCs, and PSMD is strongly associated with global cognition and executive functions in WML patients. This result provides new insights into the pathophysiology of cognitive impairment in WML patients. PSMD could be a surrogate marker for disease progression and could thus be used in therapeutic trials involving WML patients

A fluorescent double-network-structured hybrid nanogel as embeddable nanoglucometer for intracellular glucometry

National Natural Science Foundation of China [21274118, 91227120]; Program for New Century Excellent Talents in Fujian Province University; Fundamental Research Funds for the Central Universities [2012121016]; National Found for Fostering Talents of Basic Science [J1030415]The development of embeddable and remotely interrogatable nanomaterials that allow dynamic quantification of intracellular glucose levels can contribute to a better understanding of physiology. We develop a fluorescent hybrid nanogel glucometer (FNG) that is applicable for intracellular glucometry. Such a FNG (<200 nm) is comprised of ZnO quantum dots covalently bonded onto a loosely-crosslinked gel network of poly(acrylamide), which is interpenetrated in another relatively highly-crosslinked gel network of poly(N-isopropylacrylamide-co-2-acrylamidomethyl-5-fluorophenylboronic acid). This newly developed double-network-structured FNG can adapt to surrounding media of varying glucose levels, and convert the disruptions in homeostasis of glucose level with high reversibility, sensitivity, and selectivity into fluorescence signals at a fast time response. We demonstrate that the FNG can enter the model B16F10 cells and employ the signal transduction ability for fluorescent intracellular glucometry. Furthermore, we show that intracellular glucose level variations associated with a model biological reaction process can be monitored with a high glucose resolution by using the FNG embedded in cells, whilst the reaction mechanism remains nearly unchanged

Genome dynamics and diversity of Shigella species, the etiologic agents of bacillary dysentery

The Shigella bacteria cause bacillary dysentery, which remains a significant threat to public health. The genus status and species classification appear no longer valid, as compelling evidence indicates that Shigella, as well as enteroinvasive Escherichia coli, are derived from multiple origins of E.coli and form a single pathovar. Nevertheless, Shigella dysenteriae serotype 1 causes deadly epidemics but Shigella boydii is restricted to the Indian subcontinent, while Shigella flexneri and Shigella sonnei are prevalent in developing and developed countries respectively. To begin to explain these distinctive epidemiological and pathological features at the genome level, we have carried out comparative genomics on four representative strains. Each of the Shigella genomes includes a virulence plasmid that encodes conserved primary virulence determinants. The Shigella chromosomes share most of their genes with that of E.coli K12 strain MG1655, but each has over 200 pseudogenes, 300∼700 copies of insertion sequence (IS) elements, and numerous deletions, insertions, translocations and inversions. There is extensive diversity of putative virulence genes, mostly acquired via bacteriophage-mediated lateral gene transfer. Hence, via convergent evolution involving gain and loss of functions, through bacteriophage-mediated gene acquisition, IS-mediated DNA rearrangements and formation of pseudogenes, the Shigella spp. became highly specific human pathogens with variable epidemiological and pathological features

Whole Genome Distribution and Ethnic Differentiation of Copy Number Variation in Caucasian and Asian Populations

Although copy number variation (CNV) has recently received much attention as a form of structure variation within the human genome, knowledge is still inadequate on fundamental CNV characteristics such as occurrence rate, genomic distribution and ethnic differentiation. In the present study, we used the Affymetrix GeneChip® Mapping 500K Array to discover and characterize CNVs in the human genome and to study ethnic differences of CNVs between Caucasians and Asians. Three thousand and nineteen CNVs, including 2381 CNVs in autosomes and 638 CNVs in X chromosome, from 985 Caucasian and 692 Asian individuals were identified, with a mean length of 296 kb. Among these CNVs, 190 had frequencies greater than 1% in at least one ethnic group, and 109 showed significant ethnic differences in frequencies (p<0.01). After merging overlapping CNVs, 1135 copy number variation regions (CNVRs), covering approximately 439 Mb (14.3%) of the human genome, were obtained. Our findings of ethnic differentiation of CNVs, along with the newly constructed CNV genomic map, extend our knowledge on the structural variation in the human genome and may furnish a basis for understanding the genomic differentiation of complex traits across ethnic groups