Diversity and ochratoxin A-fumonisin profile of black Aspergilli isolated from grapes in China

Aspergillus spp. are a common contaminant of grapes and a major source of mycotoxins. China is the largest producer of grape in the world now, however, the toxigenic Aspergillus population on grape in this country is still largely unknown. In this study, a total of 345 strains were isolated from grapes of 13 main grapevine producing regions in China. Based on calmodulin gene sequences, eight species within Aspergillus section Nigri were identified. Among them, Aspergillus tubingensis (48.7%) was predominant, followed by Aspergillus welwitschiae (20.6%) and Aspergillus aculeatinus (11%). Average of contamination level was up to 64.19%, and we found the occurrence of section Nigri species on the surface of fresh grapes was significantly influenced by the climate (P<0.05). The subtropical monsoon climate showed the highest fungal detection rate (72.45%), followed by the temperate monsoon climate (49.82%), and the lowest frequency was found in the temperate continental climate (37.23%). Regarding mycotoxin-producing capacity, 4.4% of the total tested section Nigri isolates (137) were positive for ochratoxin A (OTA) production and 59.6% were fumonisin B2 (FB2) producers. Of those, Aspergillus carbonarius was the main OTA producer and A. welwitschiae and Aspergillus niger were the main FB2 producers with different toxigenic ability. Our results highlight the potential risk of OTA and FB2 contamination by A. carbonarius and A. welwitschiae on grape in China, respectively; management strategies should be considered for preventing and reducing the toxigenic Aspergillus and its mycotoxins.

Integrated analysis of different mRNA and miRNA profiles in human hypopharyngeal squamous cell carcinoma sensitive and resistant to chemotherapy

The purpose of this study was to identify potential miRNAs and mRNAs involved in chemotherapy insensitivity in hypopharyngeal squamous cell carcinoma (HSCC) and to explore the underlying mechanisms involved to provide diagnostic markers and therapeutic targets for HSCC. We used microarrays to identify differences in both the mRNA and miRNA expression profiles between a group (twelve patients) sensitive to chemotherapy and a resistant group (nine patients). We then employed bioinformatics tools to examine the functions and pathways involved. The genes and miRNAs most related to chemotherapy sensitivity in HSCC were screened. Finally, a miRNA-mRNA-phenotype network was constructed with an integrated analysis based on the identified miRNAs and mRNAs. Nine differentially expressed miRNAs and one hundred differentially expressed mRNAs were identified, and the functions of these genes and miRNAs were predicted. Bioinformatics analysis revealed a regulatory network consisting of eight genes and two miRNAs that influenced HSCC chemosensitivity. According to our analysis, CCL4L1 may be a potential molecular marker for HSCC chemotherapy, and excess CCL4L1 leads to the upregulation of PRAME and the downregulation of miR-375, thus decreasing HSPB8 expression and promoting chemotherapy sensitivity. Our work provides reliable data for further studies investigating the mechanism of HSCC chemotherapy sensitivity.

Predictors of episodic migraine transformation to chronic migraine: A systematic review and meta-analysis of observational cohort studies

BACKGROUND AND PURPOSE

An estimated 2.5-3.1% of people with episodic migraine develop chronic migraine in a year. Several risk factors are associated with an increased risk for this transformation. We conducted a systematic review and meta-analysis to provide quantitative and qualitative data on predictors of this transformation.

METHODS

An electronic search was conducted for published, prospective, cohort studies that reported risk factors for chronic migraine among people with episodic migraine. Risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. Quality of evidence was determined according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. Effect estimates were retrieved and summarized using risk ratios.

RESULTS

Of 5695 identified publications, 11 were eligible for inclusion. The pooled analysis (GRADE system) found "high" evidence for monthly headache day frequency ≥ 10 (risk ratio = 5.95), "moderate" evidence for depression (risk ratio = 1.58), monthly headache day frequency ≥ 5 (risk ratio = 3.18), and annual household income ≥ $50,000 (risk ratio = 0.65) and "very low" evidence for allodynia (risk ratio = 1.40) and medication overuse (risk ratio = 8.82) in predicting progression to chronic migraine.

CONCLUSIONS

High frequency episodic migraine and depression have high quality evidence as predictors of the transformation from episodic migraine to chronic migraine, while annual household income over $50,000 may be protective.

miR-124 and miR-142 enhance cisplatin sensitivity of non-small cell lung cancer cells through repressing autophagy via directly targeting SIRT1

Background: Drug resistance is a major obstacle in the treatment of non-small cell lung cancer (NSCLC). Recently, miRNAs are reported to be involved in the drug resistance of NSCLC. The roles of miR-124 and miR-142 in the multidrug resistance of NSCLC cells have been reported. However, the underlying mechanism by which miR-124 and miR-142 regulate resistance to cisplatin (CDDP) remains unknown. Methods: The expressions of miR-124, miR-142 and sirtuin 1 (SIRT1) in CDDP-sensitive and CDDP-resistant NSCLC tissues and cells were detected by qRT-PCR and western blot. IC50 value and cell proliferation were determined by MTT assay. Apoptosis was assessed by flow cytometry analysis. Autophagy was evaluated by western blot analysis of the protein levels of LC3-I, LC3-II and p62, and FITC-LC3 punctate formation assay. The interaction between miR-124 or miR-142 and SIRT1 was determined by luciferase reporter, RNA immunoprecipitation (RIP) and western blot assays. A tumor xenograft was performed to further validate the role of miR-124 and miR-142 in the sensitivity of CDDP-resistant NSCLC to cisplatin. Results: miR-124 and miR-142 were downregulated, while SIRT1 was upregulated in CDDP-resistant NSCLC tissues and cells compared to CDDP-sensitive groups. Functionally, overexpression of miR-124 and miR-142 or SIRT1 silencing enhanced the CDDP sensitivity of H1299/CDDP cells via suppressing autophagy, as evidenced by the reduced LC3-II/LC3-I radio, elevated p62 protein, and suppressed FITC-LC3 punctate formation in H1299/CDDP cells. miR-124 and miR-142 were demonstrated to co-target SIRT1. Re-expression of SIRT1 overturned miR-124 and miR-142-mediated chemosensitivity in H1299/CDDP cells via triggering autophagy. Conclusion: miR-124 and miR-142 enhance the cytotoxic effect of CDDP through repressing autophagy via targeting SIRT1 in CDDP-resistant NSCLC cells.

Drug resistance is a major obstacle in the treatment of non-small cell lung cancer (NSCLC).

Molecular mechanisms of azole resistance in Candida tropicalis isolates causing invasive candidiasis in China

OBJECTIVE

We investigated molecular mechanisms responsible for azole resistance in Candida tropicalis isolates.

METHODS

We studied 507 C. tropicalis isolates causing invasive candidiasis from ten hospitals over 5 years. Antifungal susceptibility was determined by broth microdilution methods. Point mutations in the C. tropicalis ERG11 gene that may confer azole resistance were explored and verified. The expression levels of ERG11, CYTb, MDR1 and CDR1 genes were compared in 20 fluconazole-susceptible and 20 fluconazole-resistant isolates.

RESULTS

Fluconazole-susceptible, -susceptible dose-dependent and -resistant strains accounted for 76.7% (389/507), 10.5% (53/507) and 12.8% (65/507) of C. tropicalis isolates, respectively. The ERG11 mutation A395T/W occurred in 10.7% (54/507) of isolates, all of which were resistant to fluconazole. The nucleotide mutation C461T/Y was the second most common (50/507 isolates, 9.9%), and all isolates carrying C461T/Y also had the mutation A395T/W. However, the presence of C461T did not contribute to the azole-resistant phenotype. Substitutions V125A, Y257H and G464S (<2% of isolates), which were reported for the first time in C. tropicalis, also conferred fluconazole non-susceptible phenotypes. Compared with fluconazole susceptible isolates, fluconazole-resistant isolates had higher ERG11 (fold expression level 1.42 versus 0.79, p < 0.01) but lower CYTb (fold expression level 1.26 versus 2.67, p < 0.01) gene expression levels. Three azole-resistant isolates carrying the wild-type ERG11 gene had higher levels of CDR1 and MDR1 expression.

CONCLUSIONS

ERG11 missense mutations were the major mechanism responsible for azole resistance in C. tropicalis isolates, but overexpression of ERG11, CDR1 and MDR1, as well as reduced expression of CYTb, also contributed to resistance.