Neutrophil CD64: a potential biomarker for the diagnosis of infection in patients with haematological malignancies.

METHODS: The clinical data of 76 patients with haematological malignancies and infection who were treated in our department between January 2014 and October 2019 were retrospectively analysed. To evaluate the diagnostic value of some biomarkers, infection indexes such as white blood cell count (WBC), neutrophil count (NEUT), neutrophil CD64 and procalcitonin (PCT) were compared across the patients with confirmed infection status and infection-control status. Sensitivity, specificity and area under the receiver operating characteristic curve (AUC) were also determined. RESULTS: The WBC and NEUT did not differ significantly, whereas the neutrophil CD64 and PCT levels were significantly elevated in patients with a confirmed infection status (p < 0.05), with sensitivity of 31.0%, 45.2%, 76.2% and 50%, respectively, and specificity of 90.5%, 69%, 71.4% and 64.3%, respectively. The AUC of WBC, NEUT, neutrophil CD64 and PCT was 0.528, 0.517, 0.844 and 0.599, respectively. Further highlighting their diagnostic value, the neutrophil CD64 and PCT levels in neutropenia patients were significantly upregulated in patients with infection status (p < 0.05) but the WBC and NEUT were unchanged, with sensitivity of 73.7%, 63.2%, 68% and 68.4%, respectively, and specificity of 68.4%, 52.6%, 57.9% and 63.2%, respectively. The AUC of neutrophil CD64, PCT, WBC and NEUT was 0.864, 0.593, 0.419 and 0.403, respectively. CONCLUSION: These results indicate that neutrophil CD64 is a promising biomarker with superior sensitivity and specificity for diagnosing infection in patients with haematological malignancies, especially neutropenia patients.

A novel fungal metabolite inhibits Plasmodium falciparum transmission and infection.

BACKGROUND: Malaria transmission depends on infected mosquitoes and can be controlled by transmission-blocking drugs. The recently discovered FREP1-mediated malaria transmission pathway is an excellent target to screen drugs for limiting transmission. METHODS: To identify candidate small molecules, we used an ELISA-based approach to analyze extracts from a fungal library for inhibition of the FREP1-parasite interaction. We isolated and determined one active compound by chromatography and crystallography, respectively. We measured the effects of the bioactive compound on malaria transmission to mosquitoes through standard membrane-feeding assays (SMFA) and on parasite proliferation in blood by culturing. RESULTS: We discovered the ethyl acetate extract of the fungus Purpureocillium lilacinum that inhibited Plasmodium falciparum transmission to mosquitoes. Pre-exposure to the extract rendered Anopheles gambiae resistant to Plasmodium infection. Furthermore, we isolated one novel active compound from the extract and identified it as 3-amino-7,9-dihydroxy-1-methyl-6H-benzo[c]chromen-6-one, or "pulixin." Pulixin prevented FREP1 from binding to P. falciparum-infected cell lysate. Pulixin blocked the transmission of the parasite to mosquitoes with an EC50 (the concentration that gave half-maximal response) of 11 µM based on SMFA. Notably, pulixin also inhibited the proliferation of asexual-stage P. falciparum with an EC50 of 47 nM. The compound did not show cytotoxic effects at a concentration of 116 µM or lower. CONCLUSION: By targeting the FREP1-Plasmodium interaction, we discovered that Purpureocillium lilacinum extract blocked malaria transmission. We isolated and identified the bioactive agent pulixin as a new compound capable of stopping malaria transmission to mosquitoes and inhibiting parasite proliferation in blood culture.

A diverse global fungal library for drug discovery.

BACKGROUND: Secondary fungal metabolites are important sources for new drugs against infectious diseases and cancers. METHODS: To obtain a library with enough diversity, we collected about 2,395 soil samples and 2,324 plant samples from 36 regions in Africa, Asia, and North America. The collection areas covered various climate zones in the world. We examined the usability of the global fungal extract library (GFEL) against parasitic malaria transmission, Gram-positive and negative bacterial pathogens, and leukemia cells. RESULTS: Nearly ten thousand fungal strains were isolated. Sequences of nuclear ribosomal internal transcribed spacer (ITS) from 40 randomly selected strains showed that over 80% were unique. Screening GFEL, we found that the fungal extract from Penicillium thomii was able to block Plasmodium falciparum transmission to Anopheles gambiae, and the fungal extract from Tolypocladium album was able to kill myelogenous leukemia cell line K562. We also identified a set of candidate fungal extracts against bacterial pathogens.

The role of AMP-activated protein kinase in quercetin-induced apoptosis of HL-60 cells.

Our previous studies have shown that quercetin inhibits Cox-2 and Bcl-2 expressions, and induces human leukemia HL-60 cell apoptosis. In order to investigate the role of AMP-activated protein kinase (AMPK) on quercetin-induced apoptosis of HL-60 cells, we used flow cytometry to detect cell apoptosis. The expressions of LKB1, phosphorylated AMPK (p-AMPK), and Cox-2 protein were detected in HL-60 cells and normal peripheral blood mononuclear cells (PBMCs) by western blot. The expressions of LKB1, p-AMPK, and Cox-2 were detected in HL-60 cells after culture with quercetin. The expressions of p-AMPK were detected in HL-60 cells after culture with AMPK inhibitor Compound C. Then, the expressions of LKB1, p-AMPK, and Cox-2 were detected in HL-60 cells after culture with quercetin alone or quercetin + Compound C. It was found that there was no significant difference in LKB1 between PBMCs and HL-60. p-AMPK in PBMCs was higher than that in HL-60, while Cox-2 was lower. After culture of HL-60 with quercetin, p-AMPK was increased, Cox-2 was decreased, but LKB1 remained unchanged. After culture of HL-60 with Compound C, p-AMPK was decreased. There was no significant difference in LKB1 between the quercetin-alone and the quercetin + Compound C groups. p-AMPK decreased more significantly, while Cox-2 increased more significantly in the quercetin + Compound C groups than those in the quercetin-alone groups. Taken together, these findings suggested that quercetin activates AMPK expression in HL-60 cells independent of LKB1 activation, inhibits Cox-2 expression by activating AMPK, and further regulates the Bcl-2-dependent pathways of apoptosis to exert its anti-leukemia effect.

Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells.

Quercetin is one of the naturally occurring dietary flavonol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.