Proteomic analysis of differentially expressed proteins in 5-fluorouracil-treated human breast cancer MCF-7 cells

BACKGROUND

5-Fluorouracil (5-Fu) is a commonly used chemotherapeutic agent in clinical care of breast cancer patients. However, the mechanism of how the 5-Fu works is complex and still largely unknown.

OBJECTIVE

The objective of this study was to understand the mechanism further and explore the new targets of 5-Fu.

METHODS

The differentially expressed proteins induced by 5-Fu in human breast cancer MCF-7 cells were identified by proteomic analysis. Four differentially expressed proteins were validated using Western blot and quantitative real-time reverse-transcription polymerase chain reaction analysis for protein and mRNA levels. The effect of 5-Fu on MCF-7 cells was determined by cell viability assay, transmission electron microscopy and flow cytometry analysis.

RESULTS

5-Fu dose-dependently inhibited cell proliferation with the IC50 value of 98.2 μM. 5-Fu also induced obviously morphological change and apoptosis in MCF-7 cells. Twelve differentially expressed proteins involved in energy metabolism, cytoskeleton, cellular signal transduction and tumor invasion and metastasis were identified.

CONCLUSION

These results may provide a new insight into the molecular mechanism of 5-Fu in therapy of breast cancer.

Diagnostic value of CT perfusion imaging for parotid neoplasms

OBJECTIVES

To assess the value of CT perfusion imaging in the differentiation of different histological categorization of benign tumours from malignant tumours in patients with parotid neoplasms.

METHODS

CT perfusion was successfully performed in 62 patients with parotid neoplasms whose diagnoses were confirmed by surgery or biopsy. The software generated a tissue time-density curve (TDC) and measured blood volume, blood flow, mean transit time and capillary permeability surface product. One-way ANOVA and receiver operating characteristic curves were used to analyse the difference and diagnostic efficacies of all perfusion data between each one of the benign tumours and malignancies. Statistical significance was assigned at the 5% level.

RESULTS

Pleomorphic adenomas mainly had a gradually ascending TDC. Warthin tumours showed a fast ascent followed by a fast descent. The TDC of basal cell adenomas had a fast ascension followed by a plateau, then a gradual descent. Malignant tumours mainly showed a rapidly ascending curve with a stable plateau. Significant differences were observed in blood flow, blood volume and mean transit time between pleomorphic adenomas and malignant tumours (p < 0.05) as well as in blood flow and blood volume between the Warthin tumours, the basal cell adenomas and the malignant tumours (p < 0.05). Differences in permeability surface between the basal cell adenomas and malignant tumours were significant (p < 0.01).

CONCLUSION

CT perfusion of parotid gland could provide TDC and perfusion data, which were useful in the differentiation of different histological benign tumours and malignant tumours in the parotid gland.

Melatonin receptor subtypes Mel1a and Mel1c but not Mel1b are associated with monochromatic light-induced B-lymphocyte proliferation in broilers

This study determined the effects of melatonin (MEL) and its receptors on monochromatic light-induced bursal B-lymphocyte proliferation in broiler chickens. In vivo, green light (GL) enhanced the proliferation of B lymphocytes in bursas by 16.49% to 30.83% and the expression of MEL receptor subtypes 1a (Mel1a), Mel1b, and Mel1c receptors in bursas by 6.91% to 366.98% than other light colors. However, pinealectomy reduced these parameters and eliminated the differences between GL and other light groups. In vitro, the MEL-induced bursal B-lymphocyte proliferation was most suppressed by prazosin (P = 0.001, selective Mel1c antagonist), followed by luzindole (P = 0.022, nonselective Mel1a/Mel1b antagonist), but not by 4-phenyl-2-propionamideotetralin (P = 0.144, selective Mel1b antagonist). Similarly, dibutyryl-cyclic adenosine monophosphate (cAMP; analog of cAMP; P = 0.017) but not 8-(4-chloro-phenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (P = 0.736; activator of exchange protein directly activated by cAMP) significantly inhibited bursal B-lymphocyte proliferation. These results suggest that MEL mediates GL-induced bursal B-lymphocyte proliferation through Mel1c and Mel1a receptors but not Mel1b receptors by activating the cAMP/protein kinase A pathway.

Biogeochemistry and community ecology in a spring-fed urban river following a major earthquake

In February 2011 a MW 6.3 earthquake in Christchurch, New Zealand inundated urban waterways with sediment from liquefaction and triggered sewage spills. The impacts of, and recovery from, this natural disaster on the stream biogeochemistry and biology were assessed over six months along a longitudinal impact gradient in an urban river. The impact of liquefaction was masked by earthquake triggered sewage spills (~20,000 m(3) day(-1) entering the river for one month). Within 10 days of the earthquake dissolved oxygen in the lowest reaches was <1 mg l(-1), in-stream denitrification accelerated (attenuating 40-80% of sewage nitrogen), microbial biofilm communities changed, and several benthic invertebrate taxa disappeared. Following sewage system repairs, the river recovered in a reverse cascade, and within six months there were no differences in water chemistry, nutrient cycling, or benthic communities between severely and minimally impacted reaches. This study highlights the importance of assessing environmental impact following urban natural disasters.

Isoflurane facilitates synaptic NMDA receptor endocytosis in mice primary neurons

Inhalation anesthetic isoflurane has been reported to induce caspase activation and accumulation of β-amyloid (Aβ), however, the down-stream consequences of these effects are largely unknown. Isoflurane has also been shown to impair learning and memory, however, the up-stream mechanisms of these effects remain largely to be determined. Facilitation of synaptic NMDA receptor endocytosis can reduce synaptic function, leading to learning and memory impairment. We therefore set out to determine the effects of isoflurane on synaptic NMDA receptor endocytosis. Primary neurons from wild-type and Alzheimer's disease transgenic mice were treated with 2% isoflurane for six hours. Synaptic surface levels of NMDA receptor 2B (NR2B) and NR2B internalization were determined by surface and cleavable biotinylation assay, western blot analysis and immunofluorescence. Here we show that isoflurane can induce caspase-3 activation, increase levels of β-site amyloid precursor protein-cleaving enzyme and cause accumulation of Aβ in the primary neurons. Isoflurane facilitates synaptic NR2B endocytosis as evidenced by reducing surface NR2B levels, increasing NR2B internalization, and decreasing the ratio of synaptic surface NR2B to synapsin in mice primary neurons. Moreover, caspase activation inhibitor Z-VAD and γ-secretase inhibitor L-685,458 attenuated the isoflurane-facilitated NR2B endocytosis. These results suggest that isoflurane induces caspase activation and Aβ accumulation, leading to facilitation of synaptic NMDA receptor endocytosis, which potentially serve as the upstream mechanism of the isoflurane-induced impairment of learning and memory. These findings will encourage further studies to determine the underlying mechanism by which isoflurane and other anesthetics promote Alzheimer's disease neuropathogenesis and induce cognitive dysfunction.

Patulin induces pro-survival functions via autophagy inhibition and p62 accumulation

Patulin (PAT) is one of the most common mycotoxins found in moldy fruits. Skin contact is one of the most likely exposure routes of PAT. Investigation of dermal toxicity of PAT is clearly needed and has been highlighted by WHO. In the present study, using human keratinocyte HaCaT cells as a model, we found that treatment with PAT caused an increased autophagosome accumulation. Measurements of autophagic flux demonstrated that the accumulation of autophagosomes by PAT was not directly due to enhanced autophagosome formation but due to inhibition of autophagosome degradation. Reductions in the activities of the lysosomal enzymes cathepsin B and cathepsin D by PAT might contribute to this inhibitory effect. Consistent with this, inhibition of autophagosome degradation by PAT resulted in accumulation of p62 that functioned as a pro-survival signal. The pro-survival function of p62 was found to be attributed to reactive oxygen species-mediated cytoprotective endoplasmic reticulum (ER) stress response. ER stress exerted cytoprotective effect via extracellular signal-regulated kinase1/2-dependent B-cell CLL/lymphoma 2-associated agonist of cell death inhibitory phosphorylation. Given the critical role of autophagy and its substrate p62 in carcinogenesis, our findings may have important implications in PAT-induced skin carcinogenesis.

Impact of chromosomal translocations on male infertility, semen quality, testicular volume and reproductive hormone levels

OBJECTIVE

To analyse the relationship between male infertility and chromosomal translocations, and the influence of different types of chromosomal translocations on semen quality, testicular volume and hormone levels.

METHODS

A retrospective cohort of infertile men was recruited for chromosomal analysis using standard Giemsa stain banding. Physical examinations, semen analysis, hormonal analysis and the detection of azoospermia factor (AZF) microdeletions were carried out. Men with normal fertility were used as controls.

RESULTS

Among the 1056 infertile men, 22 had chromosomal translocations (2.1%), including seven with Robertsonian translocations (0.7%), 11 with autosome-autosome reciprocal translocations (1.0%) and four with gonosome-autosome reciprocal translocations (0.4%). Left and right testicular volumes of patients with chromosomal translocations were significantly smaller than those in the fertile control group. There were no significant differences in hormone levels between patients with chromosomal translocations and fertile controls, except for significantly lower testosterone levels in patients with Robertsonian and gonosome-autosome reciprocal translocations compared with the controls. All AZF microdeletion analyses showed normal results.

CONCLUSIONS

Chromosomal translocations may cause reductions in testicular volume and testosterone level, which may impact spermatogenesis, resulting in azoospermia or oligozoospermia and male infertility.

Transcriptome sequencing of sea cucumber (Apostichopus japonicus) and the identification of gene-associated markers

Sea cucumber (Apostichopus japonicus) is an ecologically and economically important species in East and South-East Asia. This project aimed to identify large numbers of gene-associated markers and differentially expressed genes (DEGs) after lipopolysaccharides (LPS) challenge in A. japonicus using high-throughput transcriptome sequencing. A total of 162 million high-quality reads of 174 million raw reads were obtained by deep sequencing using Illumina HiSeq™ 2000 platform. Assembly of these reads generated 94 704 unigenes, with read length ranging from 200 to 16 153 bp (average length of 810 bp). A total of 36 005 were identified as coding sequences (CDSs), 32 479 of which were successfully annotated. Based on the assembly transcriptome, we identified 142 511 high-quality single nucleotide polymorphisms (SNPs). Among them, 33 775, 63 120 and 45 616 were located in sequences without predicted CDS (non-CDSs), CDSs and untranslated regions (UTRs), respectively. These putative SNPs included 82 664 transitions and 59 847 transversions. Totally, 89 375 (59.1%) were distributed in 15 473 known genes. A total of 6417 microsatellites were detected in 5970 unigenes, 3216 of which were annotated and 2481 were successfully subjected for primer design. The numbers of simple sequence repeats (SSRs) identified in non-CDSs, CDSs and UTRs were 2367, 2316 and 1734. These potential SNPs and SSRs are expected to provide abundant resources for genetic, evolutionary and ecological studies in sea cucumber. Transcriptome comparison revealed 1330, 1347 and 1291 DEGs in the coelomocytes of A. japonicus at 4 h, 24 h and 72 h after LPS challenge, respectively. Approximately 58.4% (1802) of total DEGs have been successfully annotated.

Isoflurane and sevoflurane increase interleukin-6 levels through the nuclear factor-kappa B pathway in neuroglioma cells

BACKGROUND

Isoflurane can increase pro-inflammatory cytokine interleukin (IL)-6 levels. However, the up-stream mechanism remains unknown. Nuclear factor-kappa B (NF-κB) promotes the generation of pro-inflammatory cytokines. We examined the effects of isoflurane and sevoflurane on the NF-κB signalling pathway and its association with IL-6 levels in cultured cells.

METHODS

H4 human neuroglioma cells (H4 cells), and mouse primary neurones and microglia were treated with 2% isoflurane or 4.1% sevoflurane for 6 h, for analysis of IL-6 and NF-κB. Pyrrolidine dithiocarbamate (an NF-κB inhibitor) or 2-deoxy-d-glucose (2-DG) (an inhibitor of glucose glycolysis) was applied 1 h before anaesthetic treatment.

RESULTS

Isoflurane or sevoflurane treatment increased the levels of IL-6 [isoflurane: 410% (54); sevoflurane: 290% (24)], the nuclear levels of NF-κB [isoflurane: 170% (36); sevoflurane: 320% (30)], and the transcription activity of NF-κB in H4 cells. Moreover, isoflurane enhanced the transcription activity of NF-κB in mouse microglia, but not primary neurones. Finally, pyrrolidine dithiocarbamate and 2-DG attenuated isoflurane-induced increases in IL-6 and NF-κB, and the transcription activity of NF-κB.

CONCLUSIONS

These studies in H4 cells suggest that the NF-κB signalling pathway could contribute to isoflurane or sevoflurane-induced neuroinflammation. This could lead to the targeted intervention of anaesthetic-induced neuroinflammation.

The correlation between T helper type 17 cells and clinical characters in Chinese paediatric patients with chronic hepatitis B

Interleukin (IL)-17-mediated immune response has been shown to play a critical role in inflammation-associated disease. However, its role in the pathogenesis of chronic hepatitis B virus (HBV) in paediatric patients remains unknown. We investigated the frequency of T helper type 17 (Th17) cells and evaluated the association between the Th17 and clinical characters in paediatric patients with chronic hepatitis B (CHB). The frequency of Th17 cells was detected by flow cytometry analyses from 65 paediatric patients with CHB and nine healthy controls. The degree of hepatic inflammation was graded using the histological activity index (HAI). Compared with healthy controls, the frequency of Th17 cells in peripheral blood was significantly higher in paediatric patients with CHB. The proportion of Th17 cells was higher in the patients with higher HAI score (G2-G3) compared to those subjects with lower HAI score (G0-G1), but the frequency of Th17 cells had no correlation with serum HBV DNA loads or alanine aminotransferase levels. Compared with the younger age group (age 1-6 years), Th17 cell frequency was higher in the older age group (age 7-18 years). Peripheral Th17 cell frequency is associated closely with inflammation activity of liver tissues in paediatric patients with CHB.

Serotypes, genotypes and antimicrobial resistance patterns of human diarrhoeagenic Escherichia coli isolates circulating in southeastern China

Diarrhoeagenic Escherichia coli (DEC) infection is a major health problem in developing countries. The prevalence and characteristics of DEC have not been thoroughly investigated in China. Consecutive faecal specimens from outpatients with acute diarrhoea in nine sentinel hospitals in southeastern China were collected from July 2009 to June 2011. Bacterial and viral pathogens were detected by culture and RT-PCR, respectively. DEC isolates were further classified into five pathotypes using multiplex PCR. The O/H serotypes, sequence types (STs) and antimicrobial susceptibility profiles of the DEC isolates were determined. A total of 2466 faecal specimens were collected, from which 347 (14.1%) DEC isolates were isolated. DEC was the dominant bacterial pathogen detected. The DEC isolates included 217 EAEC, 62 ETEC, 52 EPEC, 14 STEC, one EIEC and one EAEC/ETEC. O45 (6.6%) was the predominant serotype. Genotypic analysis revealed that the major genotype was ST complex 10 (87, 25.6%). Isolates belonging to the serogroups or genotypes of O6, O25, O159, ST48, ST218, ST94 and ST1491 were highly susceptible to the majority of antimicrobials. In contrast, isolates belonging to O45, O15, O1, O169, ST38, ST226, ST69, ST31, ST93, ST394 and ST648 were highly resistant to the majority of antimicrobials. DEC accounted for the majority of bacterial pathogens causing acute diarrhoea in southeastern China, and it is therefore necessary to test for all DEC, not only the EHEC O157:H7. Some serogroups or genotypes of DEC were highly resistant to the majority of antimicrobials. DEC surveillance should be emphasized.

Clinical features of Chinese patients with Huntington's disease carrying CAG repeats beyond 60 within HTT gene

Patients with Huntington's disease (HD) carrying CAG repeats beyond 60 are less frequently seen and clinical features of them have been rarely reported. We identified four unrelated patients carrying CAG repeats beyond 60 (84.0 ± 13.76, ranging from 74 to 104) from 119 Chinese HD patients via direct sequencing. These four were all early onset with a mean age at presenting symptom of 9.8 ± 1.71 years. Paternal transmission was found in three of them and the fourth was apparently sporadic. In addition, they had atypical onset symptoms including epilepsy, intellectual decline, tics and walking instability, which might lead the clinicians to make the wrong diagnosis in the early stage of disease. Our work explores clinical features of Chinese HD patients with an expanded CAG repeat over 60 and may help the clinicians make a correct diagnosis in the early stage of disease.

miR-21 is a key therapeutic target for renal injury in a mouse model of type 2 diabetes

AIMS/HYPOTHESIS

As microRNA-21 (miR-21) plays a pathological role in fibrosis, we hypothesised that it may be a therapeutic target for diabetic nephropathy.

METHODS

Abundance of miR-21 was examined in diabetic kidneys from db/db mice. The therapeutic potential of miR-21 in diabetic kidney injury was examined in db/db mice by an ultrasound-microbubble-mediated miR-21 small hairpin RNA transfer. In addition, the role and mechanisms of miR-21 in diabetic renal injury were examined in vitro under diabetic conditions in rat mesangial and tubular epithelial cell lines by overexpressing or downregulating miR-21.

RESULTS

In db/db mice, a mouse model of type 2 diabetes, renal miR-21 at age 20 weeks was increased twofold compared with db/m (+) mice at the same age, and this increase was associated with the development of microalbuminuria and renal fibrosis and inflammation. More importantly, gene transfer of miR-21 knockdown plasmids into the diabetic kidneys of db/db mice at age 10 weeks significantly ameliorated microalbuminuria and renal fibrosis and inflammation at age 20 weeks, revealing a therapeutic potential for diabetic nephropathy by targeting miR-21. Overexpression of miR-21 in kidney cells enhanced, but knockdown of miR-21 suppressed, high-glucose-induced production of fibrotic and inflammatory markers. Targeting Smad7 may be a mechanism by which miR-21 regulates renal injury because knockdown of renal miR-21 restored Smad7 levels and suppressed activation of the TGF-β and NF-κB signalling pathways.

CONCLUSIONS/INTERPRETATION

Inhibition of miR-21 might be an effective therapy for diabetic nephropathy.

Serum N-terminal pro-brain natriuretic peptide level is a significant prognostic factor in patients with severe sepsis among Southwest Chinese population

BACKGROUND

This study aimed to determine the predictive value of elevated N-terminal pro-brain natriuretic peptide (NTproBNP) for mortality in patients with severe sepsis.

PATIENTS AND METHODS

This was a retrospective study in Emergency Department of Sichuan Provincial People's Hospital, and patients were screened between January 1, 2009 and December 31, 2011. Demographic and clinical data as well as Acute Physiology And Chronic Health Evaluation II (APACHE II) and Sepsis Organ Failure Assessment (SOFA) scores were collected within the first day of admission. Survival was determined to establish its association with the NT-proBNP using logistic regression and receiver operating characteristic (ROC) curve.

RESULTS

A total of 171 patients with severe sepsis were analyzed. The median APACHE IIⅡ and SOFA scores were 11 (IQR, 7-16) and 3 (IQR, 1-5), respectively. The median C-reactive protein (CRP), procalcitonin (PCT) and NT-proBNP was 10.3 mg/dL (IQR, 3.4-21.4 mg/dL), 0.4 ng/mL (IQR, 0.2-3.6 ng/mL), and 954 (321-1576) pg/mL, respectively. The median NT-proBNP in survivors was 584 pg/mL (IQR, 321-875 pg/mL) versus 1271 (IQR, 851-1576 pg/mL) in nonsurvivors (p < 0.001). In the ROC curves, the area value was 0.89 for serum NT-proBNP, and its potent cutoff value was 1500 pg/mL. After multivariate regression analysis, NT-proBNP was significantly correlated with the mortality of severe sepsis (OR = 1.58, 95% CI 1.36-1.77).

CONCLUSIONS

Serum NT-proBNP is frequently increased in severe sepsis patients, and non-survivors have higher levels than survivors. High levels of admission NT-proBNP are associated with mortality.