Genome-wide association studies have identified susceptibility loci for esophageal squamous cell carcinoma (ESCC). We conducted a meta-analysis of all single-nucleotide polymorphisms (SNPs) that showed nominally significant P-values in two previously published genome-wide scans that included a total of 2961 ESCC cases and 3400 controls. The meta-analysis revealed five SNPs at 2q33 with P< 5 × 10−8, and the strongest signal was rs13016963, with a combined odds ratio (95% confidence interval) of 1.29 (1.19–1.40) and P= 7.63 × 10−10. An imputation analysis of 4304 SNPs at 2q33 suggested a single association signal, and the strongest imputed SNP associations were similar to those from the genotyped SNPs. We conducted an ancestral recombination graph analysis with 53 SNPs to identify one or more haplotypes that harbor the variants directly responsible for the detected association signal. This showed that the five SNPs exist in a single haplotype along with 45 imputed SNPs in strong linkage disequilibrium, and the strongest candidate was rs10201587, one of the genotyped SNPs. Our meta-analysis found genome-wide significant SNPs at 2q33 that map to the CASP8/ALS2CR12/TRAK2 gene region. Variants in CASP8 have been extensively studied across a spectrum of cancers with mixed results. The locus we identified appears to be distinct from the widely studied rs3834129 and rs1045485 SNPs in CASP8. Future studies of esophageal and other cancers should focus on comprehensive sequencing of this 2q33 locus and functional analysis of rs13016963 and rs10201587 and other strongly correlated variants.
Two atmospheric circulation systems, the mid-latitude Westerlies and the Asian summer monsoon (ASM), play key roles in northern-hemisphere climatic changes. However, the variability of the Westerlies in Asia and their relationship to the ASM remain unclear. Here, we present the longest and highest-resolution drill core from Lake Qinghai on the northeastern Tibetan Plateau (TP), which uniquely records the variability of both the Westerlies and the ASM since 32 ka, reflecting the interplay of these two systems. These records document the anti-phase relationship of the Westerlies and the ASM for both glacial-interglacial and glacial millennial timescales. During the last glaciation, the influence of the Westerlies dominated; prominent dust-rich intervals, correlated with Heinrich events, reflect intensified Westerlies linked to northern high-latitude climate. During the Holocene, the dominant ASM circulation, punctuated by weak events, indicates linkages of the ASM to orbital forcing, North Atlantic abrupt events, and perhaps solar activity changes.
Although the genetic variability of hepatitis B virus (HBV) in HBV-infected patients has been extensively studied, reports on genotypes, subtypes and mutations in the S region of HBV strains from Chinese blood donors are limited. In this study, 245 blood samples from HBsAg-positive blood donors were collected from five geographically diverse blood centers in China. The S region of HBV was amplified, and the HBV genotype and subtype were determined. The amino acid sequences of the S region were aligned, and mutations related to the failure of immunization and HBsAg detection were determined. Of the 245 samples, 228 (93 %) were genotyped successfully. We found that genotypes B, C, D and A accounted for 58.8 %, 21.9 %, 6.6 % and 3.95 % of the isolates, respectively. The distribution of HBV antigen subtypes was as follows: adw (67.6 %), adr (23.3 %) and ayw (8.7 %). Mutations were present in 39 (17.1 %) of 228 samples in the major hydrophilic region (MHR) of the S region. This study demonstrated that HBV genotype/subtype B/adw was the most frequent strain circulating in HBV-infected Chinese blood donors, followed by C/adr. The occurrence of MHR mutants in HBV-infected blood donors and the potential failure to detect some of them in collected units poses a threat to transfusion safety.
Pancreatic carcinoma is one common cancer with gradually increasing incidence during the past several decades. However, currently the candidate drugs to suppress pancreatic cancer remain lacking. This research was carried out to investigate if zerumbone, a natural cyclic sesquiterpene isolated from Zingiber zerumbet Smith, will produce the anticancer effects on pancreatic carcinoma cell lines. The results showed that zerumbone concentration, and time, dependently produced inhibitory actions on cell viability of PANC-1 cells. In addition, Hoechst 33342, AO/EB, TUNEL staining, and caspase-3 activity assay further showed that zerumbone induced apoptosis of PANC-1 cells. The expression of p53 protein was markedly upregulated, and the p21 level was also obviously elevated in zerumbone-treated PANC-1 cells. Moreover, ROS production was increased by about 149% in PANC-1 cells treated by zerumbone 30 μM. Zerumbone also produced the same antitumor activity in pancreatic carcinoma cell lines SW1990 and AsPC-1. In summary, we found that zerumbone was able to induce apoptosis of pancreatic carcinoma cell lines, indicating to be a promising treatment for pancreatic cancer.
Nematode-trapping fungi are “carnivorous” and attack their hosts using specialized trapping devices. The morphological development of these traps is the key indicator of their switch from saprophytic to predacious lifestyles. Here, the genome of the nematode-trapping fungus Arthrobotrys oligospora Fres. (ATCC24927) was reported. The genome contains 40.07 Mb assembled sequence with 11,479 predicted genes. Comparative analysis showed that A. oligospora shared many more genes with pathogenic fungi than with non-pathogenic fungi. Specifically, compared to several sequenced ascomycete fungi, the A. oligospora genome has a larger number of pathogenicity-related genes in the subtilisin, cellulase, cellobiohydrolase, and pectinesterase gene families. Searching against the pathogen-host interaction gene database identified 398 homologous genes involved in pathogenicity in other fungi. The analysis of repetitive sequences provided evidence for repeat-induced point mutations in A. oligospora. Proteomic and quantitative PCR (qPCR) analyses revealed that 90 genes were significantly up-regulated at the early stage of trap-formation by nematode extracts and most of these genes were involved in translation, amino acid metabolism, carbohydrate metabolism, cell wall and membrane biogenesis. Based on the combined genomic, proteomic and qPCR data, a model for the formation of nematode trapping device in this fungus was proposed. In this model, multiple fungal signal transduction pathways are activated by its nematode prey to further regulate downstream genes associated with diverse cellular processes such as energy metabolism, biosynthesis of the cell wall and adhesive proteins, cell division, glycerol accumulation and peroxisome biogenesis. This study will facilitate the identification of pathogenicity-related genes and provide a broad foundation for understanding the molecular and evolutionary mechanisms underlying fungi-nematodes interactions.
The fungus Arthrobotrys oligospora has multiple lifestyles. It's not only a nematode pathogen, but also a saprophyte, a pathogen of other fungi, and a colonizer of plant roots. As a nematode pathogen, A. oligospora forms adhesive networks to capture nematodes and is a model organism for understanding the interaction between these fungi and their host nematodes. In this study, the whole genome sequence of A. oligospora was reported. Our analyses of the proteome profiles of intracellular proteins from cells treated with nematode extracts for 10 h and 48 h revealed a key set of genes involved in trap formation. The changes in protein levels for some trap formation related genes were further confirmed by qPCR. The combined genome and proteome analysis identified the major genetic and metabolic pathways involved in trap formation in A. oligospora. Our results provide the first glimpse into the genome and proteome of this fascinating group of carnivorous fungi. The data should serve as a roadmap for further investigations into the interaction between nematode-trapping fungi and their host nematodes, providing broad foundations for research on the biocontrol of pathogenic nematodes.
The tuberous sclerosis complex (TSC)–mammalian target of rapamycin (mTOR) pathway is a key regulator of cellular metabolism. We used conditional deletion of Tsc1 to address how quiescence is associated with the function of hematopoietic stem cells (HSCs). We demonstrate that Tsc1 deletion in the HSCs drives them from quiescence into rapid cycling, with increased mitochondrial biogenesis and elevated levels of reactive oxygen species (ROS). Importantly, this deletion dramatically reduced both hematopoiesis and self-renewal of HSCs, as revealed by serial and competitive bone marrow transplantation. In vivo treatment with an ROS antagonist restored HSC numbers and functions. These data demonstrated that the TSC–mTOR pathway maintains the quiescence and function of HSCs by repressing ROS production. The detrimental effect of up-regulated ROS in metabolically active HSCs may explain the well-documented association between quiescence and the “stemness” of HSCs.
The aromatic chromophores, for example, perylene diimides (PDIs) are well known for their desirable absorption and emission properties. However, their stacking nature hinders the exploitation of these properties and further applications. To fabricate emissive aggregates or solid-state materials, it has been common practice to decrease the degree of stacking of PDIs by incorporating substituents into the parent aromatic ring. However, such practice often involves difficultorganic synthesis with multiple steps. A supramolecular approach is established here to fabricate highly fluorescent and responsive soft materials, which has greatly decreases the number of required synthetic steps and also allows for a system with switchable photophysical properties. The highly fluorescent smart material exhibits great adaptivity and can be used as a supramolecular sensor for the rapid detection of spermine with high sensitivity and selectivity, which is crucial for the early diagnosis of malignant tumors.
Aims: ApoL-I is a newly found component of high-density lipoprotein, and has a potential role in lipid metabolism. This study was mainly to examine the possible association of the ApoL-I gene polymorphism with obesity and plasma lipid levels in the Chinese population. Methods: Three hundred nineteen Han Chinese (109 obese and 210 nonobese control subjects) in Chengdu area were studied using polymerase chain reaction-restriction fragment length polymorphism analysis. Results: The Lys and Glu allele frequencies of the apoL-I gene at the Lys166Glu site in obese and nonobese control groups were 0.830, 0.170 and 0.814, 0.186, respectively. The Ile and Met allele frequencies of the gene at Ile244Met site in the obese and the control groups were 0.844, 0.156 and 0.831, 0.169, respectively. The 166Glu and 244Met allele frequencies of the two polymorphisms in obese subjects were not different from those in the controls, respectively (p>0.05). In the nonobese group, subjects with genotype Lys/Lys at the Lys166Glu site or Ile/Ile at the Ile244Met site had a higher serum mean concentration of triglyceride (TG) as compared with those of corresponding Glu or Met allele carriers (p<0.05). In addition, serum apoC-III and apoE levels were affected by genotypes of Lys166Glu and Ile224Met polymorphisms, respectively, in the control group (all p<0.05). Conclusion: The current study, for the first time, provides evidence that Lys166Glu and Ile244Met polymorphisms in apoL-I gene are associated with TG, apoC-III, and apoE levels in nonobese Chinese. However, these polymorphisms are not associated with obesity in the population.
The known functions of telomerase in tumor cells include replenishing telomeric DNA and maintaining cell immortality. We have previously shown the existence of a negative correlation between human telomerase reverse transcriptase (hTERT) and radiosensitivity in tumor cells. Here we set out to elucidate the molecular mechanisms underlying regulation by telomerase of radiosensitivity in MCF-7 cells. Toward this aim, yeast two-hybrid (Y2H) screening of a human laryngeal squamous cell carcinoma radioresistant (Hep2R) cDNA library was first performed to search for potential hTERT interacting proteins. We identified ubiquitin-conjugating enzyme E2D3 (UBE2D3) as a principle hTERT-interacting protein and validated this association biochemically. ShRNA-mediated inhibition of UBE2D3 expression attenuated MCF-7 radiosensitivity, and induced the accumulation of hTERT and cyclin D1 in these cells. Moreover, down-regulation of UBE2D3 increased hTERT activity and cell proliferation, accelerating G1 to S phase transition in MCF-7 cells. Collectively these findings suggest that UBE2D3 participates in the process of hTERT-mediated radiosensitivity in human breast cancer MCF-7 cells by regulating hTERT and cyclin D1.
Aim. This study aimed to investigate whether the glucagon-like peptide-1 analog liraglutide (LIRA) can protect against diabetic cardiomyopathy and explore the related mechanism. Methods. Rats were divided into 6 groups: a nondiabetic group, diabetic cardiomyopathy rats without LIRA treatment, diabetic cardiomyopathy rats with LIRA treatment (with high-, medium-, and low-dose, resp.), and diabetic cardiomyopathy rats treated with insulin. Cardiac function was examined by echocardiography before and after treatment. The histopathology of the heart was examined with H&E staining. The mRNA levels of XBP1, ATF4, and TRAF2 were analyzed by RT-PCR, and the expression of glucose-regulated protein 78 (Grp78), enhancer-binding protein homologous protein (CHOP), caspase-3, and caspase-12 was detected by western blot. Results. LIRA strongly improved cardiac function from both echocardiographic and histopathologic analyses, but insulin only partly increased cardiac function by improving FS and LVPW values. LIRA treatment can significantly decrease the expression of XBP1, ATF4, and TRAF2 (P < 0.01). LIRA also significantly downregulates the expression of Grp78, caspase-3 (P < 0.01), CHOP, and caspase-12 (P < 0.05). Conclusions. LIRA can protect against diabetic cardiomyopathy by inactivating the ER stress pathway. The improvement in cardiac function by LIRA is independent of glucose control.
Diabetes mellitus (DM) exacerbates coronary artery disease (CAD) morbidity and mortality. Mesenchymal stem cells (MSCs) play an important therapeutic role in myocardial ischemic injury. However, little is known about changes in the cardioprotective characteristics of MSCs from patients with DM.
Sternal bone marrow aspirates were taken at the time of coronary artery bypass graft surgery. The morphology and growth characteristics of hMSCs were observed in passage 3. Differences in gene expression profiling were measured by Affymetrix GeneChipHuman Genome U133 Plus 2.0 Arrays. Forty two adult male rats with experimentally CAD were randomized into three groups. MSCs from patients with CAD+DM or CAD were injected into the infarcted myocardium. Control animals received culture medium. Echocardiography, TUNEL, immunohistochemistry and Western-blot analysis were performed 4 weeks after transplantation.
Growth curves showed that proliferation of hMSCs in the CAD+DM group was significantly lower than in the CAD group. Nine transcripts of genes related to apoptosis containing Bcl-2 were found to differentiate the two groups. Transplantation of hMSCs in the infarcted border zone improved cardiac function, but DM partly impaired this effect. Similar results were observed from TUNEL, immunohistochemistry and Western-blot analysis.
hMSCs from patients with CAD+DM and CAD alone both have proliferative properties. Transplantation of hMSCs ameliorate heart function, but proliferative ability and myocardial protection decrease significantly in MSCs obtained from patients with CAD+DM compared with cultures from patients with CAD alone, possibly as a result of differences in Bcl-2 protein expression and reduced anti-apoptosis.
Mesenchymal stem cells; Coronary artery disease; Diabetes mellitus; Myocardial infarction; Bcl-2
In this article, a rapid and sensitive sample pretreatment technique for the determination of organophosphorus pesticides (OPPs) in soil samples is developed by using dispersive liquid–liquid microextraction (DLLME) combined with gas chromatography–flame photometric detection. Experimental conditions, including the kind of extraction and disperser solvent and their volumes, the extraction time, and the salt addition, are investigated, and the following experiment factors are used: 20 µL chlorobenzene as the extraction solvent; 1.0 mL acetonitrile as the disperser solvent; no addition of salt; and an extraction time of 1 min. Under the optimum conditions, the linearities for the three target OPPs (ethoprophos, chlorpyriphos, and profenofos) are obtained by five points in the concentration range of 2.5–1500 µg/kg, and three replicates are used for each point. Correlation coefficients vary from 0.9987 to 0.9997. The repeatability is tested by spiking soil samples at a concentration level of 5.0 µg/kg. The relative standard deviation (n = 3) varied between 2.0% and 6.6%. The limits of detection, based on a signal-to-noise ratio (S/N) of 3, range from 200 to 500 pg/g. This method is applied to the analysis of the spiked samples S1, S2, and S3, which are collected from the China Agriculture University's orchard, lawn, and garden, respectively. The recoveries for each target analyte are in the range between 87.9% and 108.0%, 87.4% and 108.0%, and 86.7% and 107.2%, respectively.
Clinical diagnosis of the metabolic syndrome is time-consuming and invasive. Convenient instruments that do not require laboratory or physical investigation would be useful in early screening individuals at high risk of metabolic syndrome. Examination of the autonomic function can be taken as a directly reference and screening indicator for predicting metabolic syndrome.
Methodology and Principal Findings
The EZSCAN test, as an efficient and noninvasive technology, can access autonomic function through measuring electrochemical skin conductance. In this study, we used EZSCAN value to evaluate autonomic function and to detect metabolic syndrome in 5,887 participants aged 40 years or older. The EZSCAN test diagnostic accuracy was analyzed by receiver operating characteristic curves. Among the 5,815 participants in the final analysis, 2,541 were diagnosed as metabolic syndrome and the overall prevalence was 43.7%. Prevalence of the metabolic syndrome increased with the elevated EZSCAN risk level (p for trend <0.0001). Moreover, EZSCAN value was associated with an increase in the number of metabolic syndrome components (p for trend <0.0001). Compared with the no risk group (EZSCAN value 0–24), participants at the high risk group (EZSCAN value: 50–100) had a 2.35 fold increased risk of prevalent metabolic syndrome after the multiple adjustments. The area under the curve of the EZSCAN test was 0.62 (95% confidence interval [CI], 0.61–0.64) for predicting metabolic syndrome. The optimal operating point for the EZSCAN value to detect a high risk of prevalent metabolic syndrome was 30 in this study, while the sensitivity and specificity were 71.2% and 46.7%, respectively.
Conclusions and Significance
In conclusion, although less sensitive and accurate when compared with the clinical definition of metabolic syndrome, we found that the EZSCAN test is a good and simple screening technique for early predicting metabolic syndrome.
Naïve T cells receive stimulation from the positive selecting ligand in the periphery for their survival. This stimulation does not normally lead to overt activation of T cells, as the T cells remain largely quiescent until they receive either antigenic or lymphopenic stimuli. The underlying mechanism responsible for survival and quiescence of the naïve T cells remain largely unknown. Here we report that T cell-specific deletion of Tsc1, a negative regulator of mTOR, resulted in both spontaneous losses of quiescence and cellularity, especially within the CD8 subset. The Tsc1-deficient T cells have increased cell proliferation and apoptosis. Tsc1 deletion affects the survival and quiescence of T cells in the absence of antigenic stimulation. Loss of quiescence but not cellularity was inhibited by rapamycin. Our data demonstrate that TSC-mTOR maintains quiescence and survival of T cells.
Gain of 3q26 is frequently observed in squamous cell carcinomas of mucosal origin, including those originating in the head and neck region. The human telomerase RNA component (hTERC) gene, which is located on chromosome 3q26, encodes for an RNA subunit of telomerase that maintains the length of telomeres through cellular divisions, and is activated in malignant diseases. The present study was designed to detect hTERC amplification in laryngeal lesions and evaluate whether this might serve as a supportive biomarker in histopathological analysis for in the diagnosis of laryngeal lesions.
Fluorescent in situ hybridization (FISH) was applied on formalin-fixed paraffin-embedded blocks of 93 laryngeal specimens, including 14 normal epithelium (NE), 15 mild dysplasia (Md), 18 moderate dysplasia (MD), 16 severe dysplasia (SD), 9 carcinoma in situ (CIS), and 21 invasive carcinoma (IC)).
By histopathologic examination, hTERC amplification rates in NE, Md, MD, SD, CIS and IC cases were 0% (0/14), 13.33% (2/15), 72.22% (13/18), 81.25% (13/16), 100% (9/9) and 100% (21/21), respectively. Amplification of hTERC was significantly associated with histopathologic diagnosis (P < 0.0001). The percentage of hTERC amplification in patients with MD, SD, CIS, and IC was significantly higher than those with NE or Md (P < 0.0001). The number of cells with abnormal signals increased and the abnormal signal patterns were diversified with increasing severity of laryngeal dysplasia (P < 0.0001).
The hTERC amplification is important in the development of laryngeal squamous cell carcinoma (LSCC). FISH detection of hTERC amplification may provide an effective approach in conjunction with histopathologic evaluation for differential diagnosis of laryngeal lesions.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2226606266791985
Laryngeal carcinoma; Human telomerase RNA component gene; Amplification; Fluorescent in situ hybridization
The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.
Duck; Liver; Egg; Meat; Fatty acid; Lipid oxidation
Changes in emotional state are known to alter neuronal excitability and can modify learning and memory formation. Such experience–dependent neuronal plasticity can be long-lasting and is thought to involve the regulation of gene transcription. Here we show that a single fear-inducing stimulus increases GluR2 mRNA abundance and promotes synaptic incorporation of GluR2-containing AMPA receptors (AMPARs) in mouse cerebellar stellate cells. The switch in synaptic AMPAR phenotype is mediated by noradrenaline and action potential prolongation. The subsequent rise in intracellular Ca2+ and activation of Ca2+-sensitive ERK /MAPK signaling trigger new GluR2 gene transcription and a switch in the synaptic AMPAR phenotype from GluR2-lacking, Ca2+-permeable, to GluR2-containing Ca2+-impermeable receptors on the order of hours. The change in glutamate receptor phenotype alters synaptic efficacy in cerebellar stellate cells. Thus, a single fear-inducing stimulus can induce a long-term change in synaptic receptor phenotype and may alter the activity of an inhibitory neural network.
Inhibitory transmission controls the action potential firing rate and pattern of Purkinje cell activity in the cerebellum. A long-term change in inhibitory transmission is likely to have a profound effect on the activity of cerebellar neuronal circuits. However little is known about how neuronal activity regulates synaptic transmission in GABAergic inhibitory interneurons (stellate/basket cells) in the cerebellar cortex. We have examined how glutamate released from parallel fibres (the axons of granule cells) influences postsynaptic AMPA receptors in stellate cells and modulates GABA release from these neurons. First, we found that burst stimulation of presynaptic parallel fibres changes the subunit composition of post-synaptic AMPA receptors from GluR2-lacking to GluR2-containing receptors. This switch reduces the Ca2+ permeability of AMPA receptors and the EPSP amplitude, and prolongs the duration of the synaptic current, producing a qualitative change in synaptic transmission. This switch in AMPA receptor phenotype can be induced by activation of extrasynaptic NMDA receptors and involves PICK1 and the activation of PKC. Second, activation of presynaptic NMDA receptors triggers a lasting increase in GABA release from stellate cells. These changes may provide a cellular mechanism underlying associative learning involving the cerebellum.
AIM: To investigate the contribution of periostin in nicotine-promoted gastric cancer cell proliferation, survival, invasion, drug resistance, and epithelial-mesenchymal transition (EMT).
METHODS: Gastric cancer cells were treated with nicotine and periostin protein expression was determined by immunoblotting. Periostin mRNA in gastric cancer cells was silenced using small interfering RNA (siRNA) techniques and periostin gene expression was evaluated by quantitative reverse transcription-polymerase chain reaction. Gastric cancer cells transfected with control or periostin siRNA plasmid were compared in terms of cell proliferation using the methylthiazolyldiphenyl-tetrazolium bromide assay. Cell apoptosis was compared using annexin V-fluoresceine isothiocyanate and propidium iodine double staining. Tumor invasion was determined using the Boyden chamber invasion assay, and the EMT marker Snail expression was evaluated by immunoblotting.
RESULTS: Nicotine upregulated periostin in gastric cancer cells through a COX-2 dependent pathway, which was blocked by the COX-2-specific inhibitor NS398. Periostin mRNA expression was decreased by ~87.2% by siRNA in gastric cancer cells, and stable periostin-silenced cells were obtained by G418 screening. Periostin-silenced gastric cancer cells exhibited reduced cell proliferation, elevated sensitivity to chemotherapy with 5-fluorouracil, and decreased cell invasion and Snail expression (P < 0.05).
CONCLUSION: Periostin is a nicotine target gene in gastric cancer and plays a role in gastric cancer cell growth, invasion, drug resistance, and EMT facilitated by nicotine.
Cyclooxygenase-2; Malignant growth; RNA interference; Snail; Smoking
Peptidyl-prolyl isomerase Pin1 regulates the function and/or stability of phosphoproteins by altering the conformation of specific pSer/pThr-Pro peptide bonds. In this work, a cyclic peptide library was synthesized and screened against the catalytic domain of human Pin1. The selected inhibitors contained a consensus motif of D-pThr-Pip-Nal (where Pip is L-piperidine-2-carboxylic acid and Nal is L-2-naphthylalanine). Representative compounds were tested for binding to Pin1 by isothermal titration calorimetry and inhibition of Pin1 activity and the most potent inhibitors had KD (and KI) values in the low nanomolar range. Treatment of breast cancer cells with the inhibitors, which were rendered membrane permeable by attachment of an octaarginine sequence, inhibited cell proliferation and increased the protein levels of two previously established Pin1 substrates, PML and SMRT. Finally, a second generation of cell permeable Pin1 inhibitors was designed by replacing the noncritical residues within the cyclic peptide ring with arginine residues and shown to have anti-proliferative activity against the cancer cells.
Peptidyl-prolyl cis-trans isomerization; specificity; phosphothreonine; kinetics; peptide library; cell permeability
The mammalian target of rapamycin (mTOR) is a signaling molecule that senses environmental cues, such as nutrient status and oxygen supply, to regulate cell growth, proliferation, and other functions. Unchecked, sustained mTOR activity results in defects in HSC function. Inflammatory conditions, such as autoimmune disease, are often associated with defective hematopoiesis. Here, we investigated whether hyperactivation of mTOR in HSCs contributes to hematopoietic defects in autoimmunity and inflammation. We found that in mice deficient in Foxp3 (scurfy mice), a model of autoimmunity, the development of autoimmune disease correlated with progressive bone marrow loss and impaired regenerative capacity of HSCs in competitive bone marrow transplantation. Similarly, LPS-mediated inflammation in C57BL/6 mice led to massive bone marrow cell death and impaired HSC function. Importantly, treatment with rapamycin in both models corrected bone marrow hypocellularity and partially restored hematopoietic activity. In cultured mouse bone marrow cells, treatment with either of the inflammatory cytokines IL-6 or TNF-α was sufficient to activate mTOR, while preventing mTOR activation in vivo required simultaneous inhibition of CCL2, IL-6, and TNF-α. These data strongly suggest that mTOR activation in HSCs by inflammatory cytokines underlies defective hematopoiesis in autoimmune disease and inflammation.
Cessation; public policy; smoking caused disease
Tumor necrosis factor alpha (TNF-α) is a major inflammatory mediator that exhibits actions leading to tissue destruction and hampering recovery from damage. At present, two antibodies against human TNF-α (hTNF-α) are available, which are widely used for the clinic treatment of certain inflammatory diseases. This work was undertaken to identify a novel functional epitope of hTNF-α. We performed screening peptide library against anti-hTNF-α antibodies, ELISA and competitive ELISA to obtain the epitope of hTNF-α. The key residues of the epitope were identified by means of combinatorial alanine scanning and site-specific mutagenesis. The N terminus (80–91 aa) of hTNF-α proved to be a novel epitope (YG1). The two amino acids of YG1, proline and valine, were identified as the key residues, which were important for hTNF-α biological function. Furthermore, the function of the epitope was addressed on an animal model of collagen-induced arthritis (CIA). CIA could be suppressed in an animal model by prevaccination with the derivative peptides of YG1. The antibodies of YG1 could also inhibit the cytotoxicity of hTNF-α. These results demonstrate that YG1 is a novel epitope associated with the biological function of hTNF-α and the antibodies against YG1 can inhibit the development of CIA in animal model, so it would be a potential target of new therapeutic antibodies.
Information processing in the CNS is controlled by the activity of neuronal networks composed of principal neurons and interneurons. Activity-dependent modification of synaptic transmission onto principal neurons is well studied, but little is known about the modulation of inhibitory transmission between interneurons. However synaptic plasticity at this level has clear implications for the generation of synchronized activity. We have investigated the molecular mechanism(s) and functional consequences of an activity-induced lasting increase in GABA release that occurs between inhibitory interneurons (stellate cells) in the cerebellum. Using whole cell recording and cerebellar slices, we found that stimulation of glutamatergic inputs (parallel fibres) with a physiological-like pattern of activity triggered a lasting increase in GABA release from stellate cells. This activity also potentiated inhibitory transmission between synaptically connected interneurons. Extracellular recording revealed that the enhanced inhibitory transmission reduced the firing frequency and altered the pattern of action potential activity in stellate cells. The induction of the sustained increase in GABA release required activation of NMDA receptors (NMDARs). Using pharmacological and genetic approaches we found that presynaptic cAMP/PKA signaling and RIM1α, an active zone protein, is the critical pathway that is required for the lasting enhancement of GABA release. Thus a common mechanism can underlie presynaptic plasticity of both excitatory and inhibitory transmission. This activity-dependent regulation of synaptic transmission between inhibitory interneurons may serve as an important mechanism for interneuronal network plasticity.
Inhibitory transmission; RIM1α; long-term potentiation; PKA; cerebellum; interneurons
AIM: To investigate the role of hepatoma-derived growth factor (HDGF) in liver development, especially in the hepatocyte differentiation.
METHODS: We generated transgenic mice which overexpressed HDGF in hepatocytes under the transcriptional control of mouse albumin promoter/enhancer. To examine the effects of HDGF overexpression on hepatocyte differentiation, we investigated the expression patterns of the differentiation marker genes.
RESULTS: The HDGF transgenic mice developed normally and showed no apparent abnormality in the liver. However, the gene expression patterns of the liver in adult transgenic mice were similar to those of the neonatal liver in control mice.
CONCLUSION: These findings suggest that HDGF-overexpression partially suppresses hepatocyte maturation.
Hepatoma-derived growth factor; Hepatocyte; Maturation; Transgenic mice