Mnn10 Maintains Pathogenicity in Candida albicans by Extending α-1,6-Mannose Backbone to Evade Host Dectin-1 Mediated Antifungal Immunity.

The cell wall is a dynamic structure that is important for the pathogenicity of Candida albicans. Mannan, which is located in the outermost layer of the cell wall, has been shown to contribute to the pathogenesis of C. albicans, however, the molecular mechanism by which this occurs remains unclear. Here we identified a novel α-1,6-mannosyltransferase encoded by MNN10 in C. albicans. We found that Mnn10 is required for cell wall α-1,6-mannose backbone biosynthesis and polysaccharides organization. Deletion of MNN10 resulted in significant attenuation of the pathogenesis of C. albicans in a murine systemic candidiasis model. Inhibition of α-1,6-mannose backbone extension did not, however, impact the invasive ability of C. albicans in vitro. Notably, mnn10 mutant restored the invasive capacity in athymic nude mice, which further supports the notion of an enhanced host antifungal defense related to this backbone change. Mnn10 mutant induced enhanced Th1 and Th17 cell mediated antifungal immunity, and resulted in enhanced recruitment of neutrophils and monocytes for pathogen clearance in vivo. We also demonstrated that MNN10 could unmask the surface ß-(1,3)-glucan, a crucial pathogen-associated molecular pattern (PAMP) of C. albicans recognized by host Dectin-1. Our results demonstrate that mnn10 mutant could stimulate an enhanced Dectin-1 dependent immune response of macrophages in vitro, including the activation of nuclear factor-κB, mitogen-activated protein kinase pathways, and secretion of specific cytokines such as TNF-α, IL-6, IL-1ß and IL-12p40. In summary, our study indicated that α-1,6-mannose backbone is critical for the pathogenesis of C. albicans via shielding ß-glucan from recognition by host Dectin-1 mediated immune recognition. Moreover, our work suggests that inhibition of α-1,6-mannose extension by Mnn10 may represent a novel modality to reduce the pathogenicity of C. albicans.

Abolishing Cell Wall Glycosylphosphatidylinositol-Anchored Proteins in Candida albicans Enhances Recognition by Host Dectin-1.

Fungi can shield surface pathogen-associated molecular patterns (PAMPs) for evading host immune attack. The most common and opportunistic human pathogen, Candida albicans, can shield ß-(1 3)-glucan on the cell wall, one of the major PAMPs, to avoid host phagocyte Dectin-1 recognition. The way to interfere in the shielding process for more effective antifungal defense is not well established. In this study, we found that deletion of the C. albicans GPI7 gene, which was responsible for adding ethanolaminephosphate to the second mannose in glycosylphosphatidylinositol (GPI) biosynthesis, could block the attachment of most GPI-anchored cell wall proteins (GPI-CWPs) to the cell wall and subsequently unmask the concealed ß-(1,3)-glucan. Neutrophils could kill the uncloaked gpi7 mutant more efficiently with an augmented respiratory burst. The gpi7 mutant also stimulated Dectin-1-dependent immune responses of macrophages, including activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways and secretion of specific cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and IL-12p40. Furthermore, the gpi7 null mutant could induce an enhanced inflammatory response through promoting significant recruitment of neutrophils and monocytes and could stimulate stronger Th1 and Th17 cell responses to fungal infections in vivo. These in vivo phenotypes also were Dectin-1 dependent. Thus, we assume that GPI-CWPs are involved in the immune mechanism of C. albicans escaping from host recognition by Dectin-1. Our studies also indicate that the blockage of GPI anchor synthesis is a strategy to inhibit C. albicans evading host recognition.

[Clinical Research Advances of Duodenal-Type Follicular Lymphoma--Review].

Duodenal-type follicular lymphoma (DFL) is a unique subtype of follicular lymphoma (FL), which often involves the second portion of duodenum (descending part of duodenum). Due to its specific pathological features, such as lack of follicular dendritic cells meshwork and disappearance of activation-induced cytidine deaminase expression, DFL presents an inert clinical course and is often confined to the intestinal tract. Inflammation-related biomarkers suggest that the microenvironment may play a likely role in the pathogenesis and favorable prognosis of DFL. Since patients generally have no obvious clinical symptoms and low progression rate, the treatment regimen for DFL is mainly observation and waiting (W&W) strategy. This study will review the latest research progress of epidemiology, diagnosis, treatment and prognosis of DFL in recent years.

[Omics Analysis of Ferroptosis and Establishment of Prognostic Model for multiple myeloma Patients].

OBJECTIVE: To explore the role of ferroptosis-related genes in multiple myeloma(MM) through TCGA database and FerrDb, and build a prognostic model of ferroptosis-related genes for MM patients. METHODS: Using the TCGA database containing clinical information and gene expression profile data of 764 patients with MM and the FerrDb database including ferroptosis-related genes, the differentially expressed ferroptosis-related genes were screened by wilcox.test function. The prognostic model of ferroptosis-related genes was established by Lasso regression, and the Kaplan-Meier survival curve was drawn. Then COX regression analysis was used to screen independent prognostic factors. Finally, the differential genes between high-risk and low-risk patients were screened, and enrichment analysis was used to explore the mechanism of the relationship between ferroptosis and prognosis in MM. RESULTS: 36 differential genes related to ferroptosis were screened out from bone marrow samples of 764 MM patients and 4 normal people, including 12 up-regulated genes and 24 down-regulated genes. Six prognosis-related genes (GCLM, GLS2, SLC7A11, AIFM2, ACO1, G6PD) were screened out by Lasso regression and the prognostic model with ferroptosis-related genes of MM was established. Kaplan-Meier survival curve analysis showed that the survival rate between high risk group and low risk group was significantly different(P<0.01). Univariate COX regression analysis showed that age, sex, ISS stage and risk score were significantly correlated with overall survival of MM patients(P<0.05), while multivariate COX regression analysis showed that age, ISS stage and risk score were independent prognostic indicators for MM patients (P<0.05). GO and KEGG enrichment analysis showed that the ferroptosis-related genes was mainly related to neutrophil degranulation and migration, cytokine activity and regulation, cell component, antigen processing and presentation, complement and coagulation cascades, haematopoietic cell lineage and so on, which may affect the prognosis of patients. CONCLUSION: Ferroptosis-related genes change significantly during the pathogenesis of MM. The prognostic model of ferroptosis-related genes can be used to predict the survival of MM patients, but the mechanism of the potential function of ferroptosis-related genes needs to be confirmed by further clinical studies.

[Construction of a Prognostic Model of Multiple Myeloma Based on Metabolism-Related Genes].

OBJECTIVE: To screen the prognostic biomarkers of metabolic genes in patients with multiple myeloma (MM), and construct a prognostic model of metabolic genes. METHODS: The histological database related to MM patients was searched. Data from MM patients and healthy controls with complete clinical information were selected for analysis.The second generation sequencing data and clinical information of bone marrow tissue of MM patients and healthy controls were collected from human protein atlas (HPA) and multiple myeloma research foundation (MMRF) databases. The gene set of metabolism-related pathways was extracted from Molecular Signatures Database (MSigDB) by Perl language. The biomarkers related to MM metabolism were screened by difference analysis, univariate Cox risk regression analysis and LASSO regression analysis, and the risk prognostic model and Nomogram were constructed. Risk curve and survival curve were used to verify the grouping effect of the model. Gene set enrichment analysis (GSEA) was used to study the difference of biological pathway enrichment between high risk group and low risk group. Multivariate Cox risk regression analysis was used to verify the independent prognostic ability of risk score. RESULTS: A total of 8 mRNAs which were significantly related to the survival and prognosis of MM patients were obtained (P<0.01). As molecular markers, MM patients could be divided into high-risk group and low-risk group. Survival curve and risk curve showed that the overall survival time of patients in the low-risk group was significantly better than that in the high risk group (P<0.001). GSEA results showed that signal pathways related to basic metabolism, cell differentiation and cell cycle were significantly enriched in the high-risk group, while ribosome and N polysaccharide biosynthesis signaling pathway were more enriched in the low-risk group. Multivariate Cox regression analysis showed that the risk score composed of the eight metabolism-related genes could be used as an independent risk factor for the prognosis of MM patients, and receiver operating characteristic curve (ROC) showed that the molecular signatures of metabolism-related genes had the best predictive effect. CONCLUSION: Metabolism-related pathways play an important role in the pathogenesis and prognosis of patients with MM. The clinical significance of the risk assessment model for patients with MM constructed based on eight metabolism-related core genes needs to be confirmed by further clinical studies.

[Screening of Differential Expression Autophagy Genes Related to the Prognosis of Diffuse Large B-Cell Lymphoma and Establishment of an Autophagy Model].

OBJECTIVE: To screen the differential expression of diffuse large B-cell lymphoma (DLBCL) autophagy-related gene (ARG), explore the mechanism of differential expression of autophagy gene (DEARG) in the occurrence and development of DLBCL and establish a prognostic model. METHODS: Using the NCICCR database containing clinical information and gene expression profile data of 481 patients with DLBCL and the HADb database containing 232 ARGs, the differential expression of ARG in DLBCL was determined by R language, the relationship between ARG and the occurrence and development of DLBCL was analyzed by GO and KEGG, the polygene prognostic model was established by Cox regression algorithm, the survival curve was drawn by Kaplan-Meier method, and the reliability of the prognostic model was evaluated by ROC curve. RESULTS: A total of 122 DEARGs were extracted from lymph node samples of 481 patients with DLBCL and 5 normal lymph nodes, including 4 up-regulated genes and 118 down-regulated genes. GO enrichment mainly focused on ontological annotations such as mitochondrial autophagy, autophagy regulation, and cell response to external stimuli. KEGG enrichment was mainly concentrated in cell senescence, NOD-like receptor signal pathway, PI3K-Akt signal pathway, and PD-1/PD-L1 signal pathway. Survival analysis was performed on 230 samples with complete clinical information. Univariate Cox analysis showed that 20 ARGs were significantly correlated with overall survival of DLBCL patients. Nine prognostic ARGs (HIF1A, CAPN1, ITPR1, PRKCQ, TRAIL, HDAC1, TSC2, NRG3, and MAPK3) were screened by multivariate Cox regression to establish DLBCL ARG prognostic model. Kaplan-Meier survival curve analysis showed that there was significant difference in survival rate between high risk group and low risk group (P<0.001). Multivariate Cox regression analysis showed that international prognostic index and risk value were independent prognostic indicators of DLBCL patients (P<0.05), the area under ROC curve was 0.762 and 0.747, respectively. CONCLUSION: DLBCL ARG prognostic model can be used to predict the prognosis of patients, but it still needs to be confirmed by a large sample of clinical studies.

CaIPF14030 negatively modulates intracellular ATP levels during the development of azole resistance in Candida albicans.

AIM: Widespread and repeated use of azoles, particularly fluconazole, has led to the rapid development of azole resistance in Candida albicans. We investigated the role of CaIPF14030 during the development of azole resistance in C albicans. METHODS: The expression of CaIPF14030 was measured by quantitative RT-PCR, and CaIPF14030 was disrupted by the hisG-URA3-hisG (URA-blaster) method. The sensitivity of C albicans to azoles was examined using a spot assay, and the intracellular ATP concentrations were measured by a luminometer. RESULTS: CaIPF14030 expression in C albicans was up-regulated by Ca(2+) in a calcineurin-dependent manner, and the protein was overexpressed during the stepwise acquisition of azole resistance. However, disruption or ectopic overexpression of CaIPF14030 did not affect the sensitivity of C albicans to azoles. Finally, we demonstrated that disruption of CaIPF14030 significantly increased intracellular ATP levels, and overexpression significantly decreased intracellular ATP levels in C albicans. CONCLUSION: CaIPF14030 may negatively modulate intracellular ATP levels during the development of azole resistance in C albicans.

[Bioinformatics Analysis of the Influence of Coronavirus Infection on Hematopoietic System and Potential Intervention Drugs and Their Significance for COVID-19].

OBJECTIVE: To analyze and predict the effect of coronavirus infection on hematopoietic system and potential intervention drugs, and explore their significance for coronavirus disease 2019 (COVID-19). METHODS: The gene expression omnibus (GEO) database was used to screen the whole genome expression data related with coronavirus infection. The R language package was used for differential expression analysis and KEGG/GO enrichment analysis. The core genes were screened by PPI network analysis using STRING online analysis website. Then the self-developed apparent precision therapy prediction platform (EpiMed) was used to analyze diseases, drugs and related target genes. RESULTS: A database in accordance with the criteria was found, which was derived from SARS coronavirus. A total of 3606 differential genes were screened, including 2148 expression up-regulated genes and 1458 expression down-regulated genes. GO enrichment mainly related with viral infection, hematopoietic regulation, cell chemotaxis, platelet granule content secretion, immune activation, acute inflammation, etc. KEGG enrichment mainly related with hematopoietic function, coagulation cascade reaction, acute inflammation, immune reaction, etc. Ten core genes such as PTPRC, ICAM1, TIMP1, CXCR5, IL-1B, MYC, CR2, FSTL1, SOX1 and COL3A1 were screened by protein interaction network analysis. Ten drugs with potential intervention effects, including glucocorticoid, TNF-α inhibitor, salvia miltiorrhiza, sirolimus, licorice, red peony, famciclovir, cyclosporine A, houttuynia cordata, fluvastatin, etc. were screened by EpiMed plotform. CONCLUSION: SARS coronavirus infection can affect the hematopoietic system by changing the expression of a series of genes. The potential intervention drugs screened on these grounds are of useful reference significance for the basic and clinical research of COVID-19.

Rivaroxaban versus enoxaparin for thromboprophylaxis after total hip or knee arthroplasty: a meta-analysis of randomized controlled trials.

PURPOSE: Rivaroxaban is a newly developed oral medicine that direct inhibits factor Xa for the prevention and treatment of thromboembolic disorders. The objective of this study was to compare the efficacy and safety of rivaroxaban versus enoxaparin, a medicine routinely used for thromboprophylaxis after total hip or knee arthroplasty. METHODS: We performed a meta-analysis of relevant randomized controlled trials (RCTs) identified in PubMed, Cochrane library, and Embase. The primary efficacy outcome for our meta-analysis was total venous thromboembolism (VTE) and all-cause mortality. The primary safety outcome was bleeding events, which were categorized as major, clinically relevant non-major, or minor events. RESULTS: Eight RCTs, involving 15,586 patients, were included in our meta-analysis. Compared to enoxaparin, thromboprophylaxis with rivaroxaban was associated with significantly fewer VTE and all-cause mortality [9,244 patients, risk ratio (RR) 0.56, 95% confidence interval (CI) 0.39-0.80] cases and a similar incidence of bleeding cases (major bleeding events: 13,384 patients, RR 1.65, 95% CI 0.93-2.93; clinically relevant non-major bleeding events: 13,384 patients, RR 1.21, 95% CI 0.98-1.50; total bleeding events, 13,384 patients, RR 1.10, 95% CI 0.97-1.24). The total hip or knee arthroplasty subgroup analysis revealed consistent efficacy and safety findings. CONCLUSIONS: Rivaroxaban was more effective than the recommended dose of enoxaparin and had a similar safety profile for thromboprophylaxis after hip and knee arthroplasty.

The addition of tocilizumab to DMARD therapy for rheumatoid arthritis: a meta-analysis of randomized controlled trials.

PURPOSE: Tocilizumab is a humanized monoclonal antibody that binds to the interleukin-6 receptor. The purpose of this study was to evaluate the effect of adding tocilizumab to disease-modifying antirheumatic drug (DMARD) therapy for the treatment of rheumatoid arthritis (RA). METHODS: We performed a meta-analysis of relevant randomized controlled trials (RCTs) identified in PubMed, Cochrane library, and Embase. The primary efficacy outcome was the proportion of patients with a 20% improvement in RA signs and symptoms according to American College of Rheumatology (ACR) criteria (ACR20 response). The primary safety outcomes were the proportion of patients reporting at least one adverse event and the proportion of patients reporting at least one serious adverse event. RESULTS: Four RCTs, involving 2701 patients, were included in our meta-analysis. The addition of tocilizumab to therapeutic regimens with DMARDs was associated both clinically and statistically with an increased number of patients achieving the ACR20 response [8 mg/kg, risk ratio (RR) 2.53, 95% confidence interval (CI) 1.89-3.39; 4 mg/kg, RR 1.96, 95% CI 1.40-2.73], as well as the ACR50 and ACR70 response, and showing remission according to the Disease Activity Score based on 28 joints. However, the benefits were gained at the expense of the tendency of the patient to experience more adverse events (8 mg/kg, RR 1.12, 95% CI 1.03-1.20; 4 mg/kg, RR 1.08, 95% CI 1.00-1.17). The new finding was that the clinical benefit from the increased tocilizumab dose (from 4 to 8 mg/kg) was not correlated with a higher incidence of adverse events. CONCLUSIONS: The superior efficacy of combined tocilizumab + DMARD therapy is associated with the tendency for the patient to have more adverse events. Consequently, the benefits and disadvantages of such combined treatments should be carefully balanced against each other in RA therapy. We suggest that 8 mg/kg every 4 weeks should be the recommended dose of tocilizumab.

Ertapenem versus piperacillin/tazobactam for the treatment of complicated infections: a meta-analysis of randomized controlled trials.

BACKGROUND: Ertapenem, a new carbapenem with a favorable pharmacokinetic profile, has been approved for the treatment of complicated intra-abdominal Infections (cIAIs), acute pelvic infections (APIs) and complicated skin and skin-structure infections (cSSSIs). The aim of this study is to compare the efficacy and safety of ertapenem with piperacillin/tazobactam, which has been reported to possess good efficacy for the treatment of these complicated infections. METHODS: We performed a meta-analysis of randomized controlled trials identified in PubMed, Cochrane library and Embase that compared the efficacy and safety of ertapenem with piperacillin/tazobactam for the treatment of complicated infections including cIAIs, APIs, cSSSIs. The primary efficacy outcome was clinical treatment success assessed at the test-of-cure visit. The primary safety outcome was drug related clinical and laboratory adverse events occurred during the treatment and the post-treatment period. RESULT: Six RCTs, involving 3161 patients, were included in our meta-analysis. Ertapenem was associated similar clinical treatment success with piperacillin/tazobactam for complicated infections treatment (clinically evaluable population, 1937 patients, odds ratios: 1.15, 95% confidence intervals: 0.89-1.49; modified intention to treat population, 2855 patients, odds ratios: 1.03, 95% confidence intervals: 0.87-1.22). All of secondary efficacy outcomes analysis obtained similar findings with clinical treatment success. No difference was found about the incidence of drug related adverse events between ertapenem and piperacillin/tazobactam groups. CONCLUSION: This meta-analysis provides evidence that ertapenem 1 g once a day can be used as effectively and safely as recommended dose of piperacillin/tazobactam, for the treatment of complicated infections, particularly of mild to moderate severity. It is an appealing option for the treatment of these complicated infections.

Effect of Interaction between Adenosine and Nitric Oxide on Central Nervous System Oxygen Toxicity.

The metabolism of adenosine (ADO) and nitric oxide (NO) in brain tissues is closely associated with the change of oxygen content. They have contrary effects in the onset of hyperbaric oxygen (HBO)-induced central nervous system oxygen toxicity (CNS OT): ADO can suppress the onset, while NO promotes it. We adopted the ADO-augmenting measure and NO-inhibiting measure in this study and found the combined use had a far superior preventive and therapeutic effect in protecting against CNS OT compared with the use of either measure alone. So we hypothesized that there is an interaction between ADO and NO which has an important impact on the onset of CNS OT. On this basis, we administered ADO-augmenting or ADO-inhibiting drugs to rats. After exposure to HBO, the onset of CNS OT was evaluated, followed by the measurement of NO content in brain tissues. In another experiment, rats were administered NO-augmenting or NO-inhibiting drugs. After exposure to HBO, the onset of CNS OT was evaluated, followed by measurement of the activities of ADO metabolism-related enzymes in brain tissues. The results showed that, following ADO augmentation, the content of NO and its metabolite was significantly reduced, and the onset of CNS OT significantly improved. After ADO inhibition, just the opposite was observed. NO promotion resulted in a decrease in the activity of ADO-producing enzyme, an increase in the activity of ADO-decomposing enzyme, and an aggravation in CNS OT. The above results were all reversed after an inhibition in NO content. Studies have shown that exposure to HBO has a significant impact on the content of ADO and NO in brain tissues as well as their biological effects, and ADO and NO might have an intense interaction, which might generate an important effect on the onset of CNS OT. The prophylaxis and treatment effects of CNS OT can be greatly enhanced by augmenting ADO and inhibiting NO.

RTA2, a novel gene involved in azole resistance in Candida albicans.

Widespread and repeated use of azoles, particularly fluconazole, has led to the rapid development of azole resistance in Candida albicans. Overexpression of CDR1, CDR2, and CaMDR1 has been reported contributing to azole resistance in C. albicans. In this study, hyper-resistant C. albicans mutant, with the above three genes deleted, was obtained by exposure to fluconazole and fluphenezine for 28 passages. Thirty-five differentially expressed genes were identified in the hyper-resistant mutant by microarray analysis; among the 13 up-regulated genes, we successfully constructed the rta2 and ipf14030 null mutants in C. albicans strain with deletions of CDR1, CDR2 and CaMDR1. Using spot dilution assay, we demonstrated that the disruption of RTA2 increased the susceptibility of C. albicans to azoles while the disruption of IPF14030 did not influence the sensitivity of C. albicans to azoles. Meanwhile, we found that ectopic overexpression of RTA2 in C. albicans strain with deletions of CDR1, CDR2 and CaMDR1 conferred resistance to azoles. RTA2 expression was found elevated in clinical azole-resistant isolates of C. albicans. In conclusion, our findings suggest that RTA2 is involved in the development of azole resistance in C. albicans.

Cap1p plays regulation roles in redox, energy metabolism and substance transport: an investigation on Candida albicans under normal culture condition.

Cap1p, a transcription factor in Candida albicans, is believed to be required for tolerance to oxidative stress. However, no information is available concerning its function on basal transcriptional profile. In this study, differentially expressed genes between the CAP1-deleted strain and its parental strain under normal culture condition were identified through microarray analysis. Notably, among the 48 down-regulated genes with the deletion of CAP1, there were three clusters, functionally related to intracellular redox, energy metabolism and substance transport. IPF7817, IPF11105 and FDH11, the three putative Cap1p target genes functionally related to redox, were shown to be activated by oxidative stress in a Cap1p-dependent manner. Furthermore, rhodamine 6G efflux analyses demonstrated that Cap1p contributed to the energy-driven efflux. Taken together, these results reveal that Cap1p plays a significant role in redox status regulation, energy metabolism and substance transport under normal culture condition.

Antifungal activities and action mechanisms of compounds from Tribulus terrestris L.

Antifungal activity of natural products is being studied widely. Saponins are known to be antifungal and antibacterial. We used bioassay-guided fractionation to have isolated eight steroid saponins from Tribulus terrestris L., which were identified as hecogenin-3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-8), tigogenin-3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-9), hecogenin-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-10), hecogenin-3-O-beta-D-xylopyranosyl (1-->3)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-11), tigogenin-3-O-beta-D-xylopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-galactopyranoside (TTS-12), 3-O-[beta-D-xylopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-[alpha-L-rhamnopyranosyl (1-->2)]-beta-D-galactopyranosyl]-26-O-beta-D-glucopyranosyl-22-methoxy-(3beta,5alpha,25R)-furostan-3,26-diol (TTS-13), hecogenin-3-O-beta-D-glucopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-14), tigogenin-3-O-beta-D-glucopyranosyl (1-->2)-[beta-D-xylopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (TTS-15). The in vitro antifungal activities of the eight saponins against five yeasts, Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis and Cryptococcus neoformans were studied using microbroth dilution assay. In vivo activity of TTS-12 in a Candida albicans vaginal infection model was studied in particular. The results showed that TTS-12 and TTS-15 were very effective against several pathogenic candidal species and Cryptococcus neoformans in vitro. It is noteworthy that TTS-12 and TTS-15 were very active against Candida albicans (MIC(80) = 10 and 2.3 microg/mL) and Cryptococcus neoformans (MIC(80) = 1.7 and 6.7 microg/mL). Phase contrast microscopy showed that TTS-12 inhibited hyphal formation, an important virulence factor of Candida albicans, and transmission electron microscopy showed that TTS-12 destroyed the cell membrane of Candida albicans. In conclusion, TTS-12 has significant in vitro and in vivo antifungal activity, weakening the virulence of Candida albicans and killing fungi through destroying the cell membrane.

Glutamate metabolism of astrocytes during hyperbaric oxygen exposure and its effects on central nervous system oxygen toxicity.

Hyperbaric oxygen (HBO) has been used widely in many underwater missions and clinical work. However, exposure to extremely high oxygen pressure may cause central nervous system oxygen toxicity (CNS-OT). The regulation of astrocyte glutamate metabolism is closely related to epilepsy. This study aimed to observe the effects of HBO exposure on glutamate metabolism in astrocytes and confirm the role of glutamate metabolism in CNS-OT. Anesthetized rats were exposed to 5 atmosphere absolute HBO for 80 min and microdialysis samples of brain interstitial fluid were continuously collected. Extracellular glutamate and glutamine concentrations were also detected. Freely moving rats were exposed to HBO of the same pressure for 20 min and glutamine synthetase (GS) activity in brain tissues was measured. Finally, we observed the effects of different doses of drugs related to glutamate metabolism on the latency of CNS-OT. Results showed that HBO exposure significantly increased glutamate content, whereas glutamine content was significantly reduced. Moreover, HBO exposure significantly reduced GS activity. Glutamate transporter-1 (GLT-1) selective antagonist ceftriaxone prolonged CNS-OT latency, whereas GLT-1 selective inhibitor dihydrokainate shortened CNS-OT latency. In summary, HBO exposure improved glutamate concentration and reduced glutamine concentration by inhibition of GS activity. GLT-1 activation also participated in the prevention of HBO-induced CNS-OT. Our research will provide a potential new target to terminate or attenuate CNS-OT.

Effects of adenosine metabolism in astrocytes on central nervous system oxygen toxicity.

Hyperbaric oxygen (HBO) is widely used in military operations, especially underwater missions. However, prolonged and continuous inhalation of HBO can cause central nervous system oxygen toxicity (CNS-OT), which greatly limits HBO's application. The regulation of astrocytes to the metabolism of adenosine is involved in epilepsy. In our study, we aimed to observe the effects of HBO exposure on the metabolism of adenosine in the brain. Furthermore, we aimed to confirm the possible mechanism underlying adenosine's mediation of the CNS-OT. Firstly, anesthetized rats exposed to 5 atm absolute HBO for 80 min. The concentrations of extracellular adenosine, ATP, ADP, and AMP were detected. Secondly, free-moving rats were exposed to HBO at the same pressure for 20 min, and the activities of 5'-nucleotidase and ADK in brain tissues were measured. For the mechanism studies, we observed the effects of a series of different doses of drugs related to adenosine metabolism on the latency of CNS-OT. Results showed HBO exposure could increase adenosine content by inhibiting ADK activity and improving 5'-nucleotidase activity. And adenosine metabolism during HBO exposure may be a protective response against HBO-induced CNS-OT. Moreover, the improvement of adenosine concentration, activation of adenosine A1R, or suppression of ADK and adenosine A2AR, which are involved in the prevention of HBO-induced CNS-OT. This is the first study to demonstrate HBO exposure regulated adenosine metabolism in the brain. Adenosine metabolism and adenosine receptors are related to HBO-induced CNS-OT development. These results will provide new potential targets for the termination or the attenuation of CNS-OT.

Bst1 is required for Candida albicans infecting host via facilitating cell wall anchorage of Glycosylphosphatidyl inositol anchored proteins.

Glycosylphosphatidyl inositol anchored proteins (GPI-APs) on fungal cell wall are essential for invasive infections. While the function of inositol deacylation of GPI-APs in mammalian cells has been previously characterized the impact of inositol deacylation in fungi and implications to host infection remains largely unexplored. Herein we describe our identification of BST1, an inositol deacylase of GPI-Aps in Candida albicans, was critical for GPI-APs cell wall attachment and host infection. BST1-deficient C. albicans (bst1Δ/Δ) was associated with severely impaired cell wall anchorage of GPI-APs and subsequen unmasked ß-(1,3)-glucan. Consistent with the aberrant cell wall structures, bst1Δ/Δ strain did not display an invasive ability and could be recognized more efficiently by host immune systems. Moreover, BST1 null mutants or those expressing Bst1 variants did not display inositol deacylation activity and exhibited severely attenuated virulence and reduced organic colonization in a murine systemic candidiasis model. Thus, Bst1 can facilitate cell wall anchorage of GPI-APs in C. albicans by inositol deacylation, and is critical for host invasion and immune escape.

Effects of Changtai granules, a traditional compound Chinese medicine, on chronic trinitrobenzene sulfonic acid-induced colitis in rats.

AIM: To study the effects of Changtai granules (CTG), a traditional compound Chinese medicine, on chronic trinitrobenzene sulfonic acid-induced colitis in rats. METHODS: Healthy adult Sprague-Dawley (SD) rats of both sexes, weighing 250-300 g, were employed in the present study. The rat colitis models were induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enemas at a concentration of 100 mg/kg in 50% ethanol. The experimental animals were randomly divided into dexamethasone (DX) treatment, CTG treatment, and model control groups, which were intracolicly treated daily with DX (0.2 mg/kg), CTG at doses of 2.9, 5.7 and 11.4 g crude drug/kg, and the equal amount of saline respectively from 6 h following induction of the colitis in rats inflicted with TNBS to the end of study. A normal control group of rats treated without TNBS but saline enema was also included in the study. After 3 wk of treatment, the animals were assessed for colonal inflammatory and ulcerative responses with respect to mortality, frequency of diarrhea, histology and myeloperoxidase activity (MPO). RESULTS: The therapeutic effect of CTG on ulcerative colitis (UC) was better than DX. CTG effectively inhibited the activity of granulocytes, macrophages and monocytes in a dose-dependent manner. Also it reduced MPO and formation of inflammation in colonic mucosal tissue. Furthermore, administration of CTG significantly prevented body mass loss and death, and decreased frequency of diarrhea in UC rats, when compared with the model control group rats. CONCLUSION: CTG would prove to be an ideal drug for chronic UC, and is warranted to be studied further.

Probiotic BIFICO cocktail ameliorates Helicobacter pylori induced gastritis.

AIM: To determine the protective effect of triple viable probiotics on gastritis induced by Helicobacter pylori (H. pylori) and elucidate the possible mechanisms of protection. METHODS: Colonization of BIFICO strains in the mouse stomach was determined by counting colony-forming units per gram of stomach tissue. After treatment with or without BIFICO, inflammation and H. pylori colonization in the mouse stomach were analyzed by hematoxylin and eosin and Giemsa staining, respectively. Cytokine levels were determined by enzyme-linked immunosorbent assay and Milliplex. The activation of nuclear factor (NF)-κB and MAPK signaling in human gastric epithelial cells was evaluated by Western blot analysis. Quantitative reverse transcription-polymerase chain reaction was used to quantify TLR2, TLR4 and MyD88 mRNA expression in the mouse stomach. RESULTS: We demonstrated that BIFICO, which contains a mixture of Enterococcus faecalis, Bifidobacterium longum and Lactobacillus acidophilus, was tolerant to the mouse stomach environment and was able to survive both the 8-h and 3-d courses of administration. Although BIFICO treatment had no effect on the colonization of H. pylori in the mouse stomach, it ameliorated H. pylori-induced gastritis by significantly inhibiting the expression of cytokines and chemokines such as TNF-α, IL-1ß, IL-10, IL-6, G-CSF and MIP-2 (P < 0.05). These results led us to hypothesize that BIFICO treatment would diminish the H. pylori-induced inflammatory response in gastric mucosal epithelial cells in vitro via the NF-κB and MAPK signaling pathways. Indeed, we observed a decrease in the expression of the NF-κB subunit p65 and in the phosphorylation of IκB-α, ERK and p38. Moreover, there was a significant decrease in the production of IL-8, TNF-α, G-CSF and GM-CSF (P < 0.05), and the increased expression of TLR2, TLR4 and MyD88 induced by H. pylori in the stomach was also significantly reduced following BIFICO treatment (P < 0.05). CONCLUSION: Our results suggest that the probiotic cocktail BIFICO can ameliorate H. pylori-induced gastritis by inhibiting the inflammatory response in gastric epithelial cells.