Combined Transcriptome and Metabolome Analysis Reveals That the Potent Antifungal Pyrylium Salt Inhibits Mitochondrial Complex I in Candida albicans

Based on the structural modification of SM21, xy12, a new pyrylium salt derivative with enhanced antifungal activities, was synthesized. The MICs (MIC90) of xy12 against Candida albicans ranged from 0.125 to 0.25 μg/mL, about 2-fold lower than those of SM21. In addition, xy12 inhibited hypha and biofilm formation in C. albicans in a dose-dependent manner. A total of 3,454 differentially expressed genes and 260 differential metabolites were identified in the xy12-treated C. albicans by RNA-seq and non-targeted metabolomics. By integrating KEGG pathway enrichment analysis, we found that inhibition of oxidative phosphorylation was the important antifungal mechanism of action of xy12. Electron transport through mitochondrial respiratory complexes I to IV is the common process of oxidative phosphorylation. Compared with the sensitivity of the wild-type SC5314 to xy12, decreased sensitivities in mitochondrial complex I (CI)-deficient mutants and increased sensitivities in mitochondrial complex III- and IV-deficient mutants suggested that the antifungal effects of xy12 were dependent on CI. Consistently, xy12 exhibited antagonism with rotenone, an inhibitor of CI, and significantly inhibited the expression and activity of CI. Meanwhile, the phenotypes in the xy12-treated C. albicans were similar to those in the CI-deficient mutants, such as decreased ATP production, reduced mitochondrial membrane potential, loss of mitochondrial DNA, inability to utilize nonfermentative carbon sources, and decreased cell wall N-linked mannoproteins. Collectively, our results revealed that the pyrylium salt xy12 could constrain oxidative phosphorylation by inhibiting mitochondrial complex I in C. albicans, providing a novel lead compound for the development of mitochondria-targeted antifungal drugs. IMPORTANCE The development of new antifungal drugs is critical for solving the problem of antifungal resistance and expanding the limited variety of clinical antifungal drugs. Based on the modification of the pyrylium salt SM21, a new lead compound, xy12, was synthesized which was effective against Candida species both in vitro and in vivo. In this study, conjoined analysis of the transcriptome and metabolome elucidated the antifungal mechanism of action of xy12, which inhibited the activity of mitochondrial complex I in C. albicans. Targeting fungi-specific mitochondrial complex proteins has been reported as a promising antifungal strategy. Our study provided a new lead compound for targeting C. albicans mitochondrial complex I, which could be beneficial for discovering novel antifungal drugs.

[Correlation between compassion fatigue and workplace violence in emergency department nurses]

Objective: To investigate the workplace violence and compassion fatigue of nurses in emergency department and to explore the relationship between the two. Methods: The general information questionnaire, workplace violence scale and professional quality of life scale were used to investigate 957 emergency department nurses of 28 Level II hospitals and above. Results: The scores of each dimension of the professional quality of life scale for nurses in the emergency department were: compassion satisfaction score was 29.91±7.82, the burnout score was 26.63±5.66, and the second trauma score was 23.17±5.94. The total score of compassion fatigue is 49.80±10.42. The incidence of workplace violence was 77.6%. Workplace violence was negatively correlated with compassion satisfaction (r=-0.250, P<0.01) , and positively correlated with burnout, secondary trauma, and total compassion fatigue (r=0.349、0.340、0.384, P<0.01) . Whether there is only non-physical violence in the compassion satisfaction, burnout, secondary trauma, compassion fatigue total score is not statistically significant. Conclusion: Compassion fatigue is more serious in emergency department nurses, and the incidence of workplace violence is higher. Workplace violence has a positive effect on compassion fatigue. Nursing managers should actively prevent workplace violence and improve the working environment, thus reducing empathy fatigue.

[Protective effects of oligomeric proanthocyanidins in mice exposed to paraquat]

Objective: To investigate the protective effect of oligomeric proanthocyanidins (OPCs) in paraquat-exposed mice. Methods: An acute lung injury model was established by a single intraperitoneal injection of paraquat (PQ) in BALB/c mice. The mice were randomized into control group, paraquat-exposed group (PQ group) , oligomeric proanthocyanidins group (OPCs group) , and paraquat and oligomeric proanthocyanidins-exposed group (PQ+OPCs group) , with 10 mice in each group. Only normal saline was intraperitoneally injected into the mice in the control group. The mice in the PQ group were divided into 8 subgroups according to the dose of poison administered, i.e., 0, 25, 50, 75, 100, 150, 200, and 300 mg/kg; the mice in each subgroup were given a single intraperitoneal injection of PQ and were observed and recorded for death at 3, 6, 12, 24, 36, 48, 60, 84, and 96 hours after PQ injection. Origin 8.0 was used to calculate the median lethal dose (LD(50)) of the mice at 24, 36, 48, and 60 hours after PQ injection, and the PQ dose (100 mg/kg, ip) was chosen based on the accumulated mortality rate. An OPCs-treated experimental model was established by an intraperitoneal injection of OPCs followed by a single PQ injection (100 mg/kg, ip) 1 hour later to observe the effects of OPCs on the apparent poisoning effect and fatality rate in PQ-induced mice. Immunohistochemistry was used to determine the effect of OPCs on PQ-induced lung tissue lesions. The peripheral blood samples of the mice were collected to determine the effects of OPCs on PQ-induced inflammatory factors such as tumor necrosis factor-α (TNF-α) , interleukine-1β (IL-1β) , and transforming growth factor-β1 (TGF-β1) using enzyme-linked immunosorbent assay. Results: The mortality rate was significantly correlated with the dose and exposure time in PQ-exposed mice; the mortality rate gradually increased with increasing dose and exposure time of the poison (P<0.05) . The LD(50) values for the mice were 216.67, 124.11, and 71.24 mg/kg at 24, 48, and 72 hours after PQ exposure, respectively. PQ could induce animal death at 12 hours after injection, and the mortality rate of the animals was 40% (4/10) at 48 hours after PQ exposure. The PQ-induced mortality rate of the mice in the PQ+OPCs group was reduced, and the mortality rate of the animals was 10% (1/10) at 48 hours after PQ exposure. Compared with treatment in the control group, OPCs exposure alone had no significant effect on the expression of TNF-α and TGF-β1 in the peripheral blood (P>0.05) , but it significantly inhibited the expression of IL-1β (P<0.05) . After 48 hours, the expression of TNF-α, TGF-β1, and IL-1β in peripheral blood significantly increased by 39%, 45%, and 38%, respectively, in the PQ group (P<0.05) , but they significantly decreased by 31%, 13%, and 22%, respectively, in the OPCs+PQ group as compared with the PQ group (P<0.05) . Conclusion: OPCs pretreatment can significantly alleviate PQ-induced poisoning effect.

[Abnormal functional connectivity between sublaterodorsal nucleus and the motor cortex in Parkinson's disease with rapid-eye-movement sleep behavior disorder]

Objective: To investigate the abnormal functional connectivity between sublaterodorsal nucleus (SLD) and the brain motor areas in Parkinson's disease with or without rapid-eye-movement (REM) sleep behavior disorder by resting state functional magnetic resonance imaging (rfMRI). Methods: A total of 64 subjects recruited in the Department of Neurology, the People's Hospital of Zhengzhou University were enrolled in this study from August 2014 to December 2017 according to international diagnosis criteria, 20 cases with PD-RBD (PD-RBD group), 23 cases without PD-nRBD (PD-nRBD group) and 21 age, gender-matched healthy controls (HC group). All subjects were examined by Hoehn-Yahr, UPDRS-Ⅲ and rfMRI. Resluts: UPDRS-Ⅲ scores and Hoehn-Yahr staging were showed significantly different from that in the HC group(KW=-27.35, P<0.001) but showed no significantly difference from that in the PD-nRBD group(KW=6.01, P=0.807). Compared with the control group, the FC analysis showed reduced correlations from the left SLD to the right orbital middle frontal gyrus(T=-4.567 8, P<0.001), the left cingulate gyrus(T=-3.196 0,P<0.001), the left cerebellum(T=-4.267 0,P<0.001) and the right midbrain(T=-4.773 7, P<0.001), from the right SLD to the bilateral cerebellum (T(left)=-5.040 1, T(right)=-4.210 5, P<0.001), the left precuneus(T=-4.468 2,P<0.001) and the left precentral gyrus (T=-4.473 9,P<0.001) in the PD-RBD. The correlations between the left SLD and left cerebellum, right midbrain and between the right SLD and left precuneus, left precentral gyrus were negative correlated with the motor functional tests. Conclusions: There are abnormal functional connectivity from the SLD to the motor areas in PD-RBD patients, leading to clinical PD-RBD motor symptoms and movement disorders.

Photocatalytic and adsorption property of ZnS–TiO2/RGO ternary composites for methylene blue degradation

The visible light–driven ZnS–TiO2/RGO nanocomposites, with good visible light–driven photocatalytic activity, utilizing graphene oxide as precursor, were successfully synthesized via a facile solvothermal thermal method with graphene oxide as precursor. Ti4+ ions were derived from titanium dioxide powder (TiO2, P25) and tetrabutyl titanate. S2− ions and Zn2+ ions were provided by sodium sulfide and zinc acetate, respectively. The photocatalytic and absorbance activity of the nanocomposites was investigated through the photocatalytic degradation of methylene blue in aqueous solution. The results showed that the ZnS–TiO2/RGO nanocomposite prepared by tetrabutyl titanate exhibited better photocatalytic and adsorbance activity for methylene blue under visible light irradiation and its photocatalytic efficiency reached 90% in 60-min light irradiation, almost 1.5 times that of the synthesized ZnS–TiO2/RGO by P25, which was attributed to a cooperative reaction because of an increase of photo-absorption effect of graphene sheets and photocatalytic effect of ZnS nanoparticles. The adsorbance activity for ZnS–TiO2/RGO–tetrabutyl titanate) reached 48%, which was almost 1.7 times higher than that of ZnS–TiO2/RGO-P25 and almost 3.7 times higher than that of ZnS/RGO.

[Mechanism of action for oligomeric proanthocyaniclins in pava qnat-induced acute lung injury]

Objective: The present study was designed to evaluate the protective effects of oligomeric proanthocyanidins (OPC) in mice exposed to paraquat (PQ) , and to explore the molecular mechanism. Methods: Four experimental groups were designed.

CONTROL GROUP

10 BALB/c mice were intraperitoneally injected with normal saline) . PQ group: 10 BALB/c mice were intraperitoneally injected with PQ (100 mg/kg) . PQ+OPC group: 10 BALB/c mice were administered with OPC (100 mg/kg) for 1 h before PQ (100 mg/kg) expo-sure. OPC group: 10 BALB/c mice were intraperitoneally injected with OPC (100 mg/kg) . The peripheral blood samples or lung tissue samples were collected at the designed time points for measuring the levels of oxi-dative stress indicators, the related protein levels of nuclear factor-kappa B (NF-κB) pathway and nuclear fac-tor erythroid related factor-2 (Nrf2) pathway. Results: Compared with the control group, the level of reactive oxygen species (ROS) , the content of malondialdehyde (MDA) in the PQ group were significantly induced, and the activity of superoxide dismutase (SOD) in the PQ group was decreased in the peripheral blood. As com-pared with the PQ group, the level of ROS and the content of MDA in the PQ+OPC group were significantly re-duced, the activity SOD in the PQ+OPC group was increased in the peripheral blood; the level of ROS and the content of MDA were also reduced in lung tissues in the PQ+OPC group. Moreover, compared with the con-trol group, the phosphorylation of IκBα and the expression of NF-κB p65 were increased in lung tissues in the PQ group. The phosphorylation of IκBα and the expression of NF-κB p65 were decreased in lung tissues in the PQ+OPC group as compared with the PQ group. In addition, compared with the control group, the expressions of HO-1 and Nrf2 were increased in lung tissues in OPC group, and these were decreased in lung tissues in PQ groups. Furthermore, the expressions of HO-1 and Nrf2 were also increased in lung tissues in PQ+OPC as com-pared with the PQ group. Conclusion: OPC could alleviate PQ-induced systemic toxicity in mice by regulating oxidative stress via NF-κB and Nrf2 pathway.

[Cement augmentation for vertebral osteolytic metastatic lesions: an evaluation on postoperative CT]

Objective: To evaluate the effectiveness of cement augmentation on the osteolytic lesion in patients with vertebral metastasis. Methods: A total of consecutive 132 patients with 268 vertebral metastatic lesions treated with PVP from January 2008 to December 2016 in Zhongda Hospital were enrolled in this study. Retrospective analysis of preoperative, postoperative 3 days, 3 months, 6 months, 12 months and ≥ 18 months imaging data on CT, the local control and progression of the tumor were evaluated by MDA response criteria. The local control rates were compared between the groups with the different rate of cement filling by Chi²-test. Results: Vertebroplasty procedures were performed successfully in all 268 vertebrae under DSA guidance, and the mean volume of PMMA injected in each vertebra was 0.7-8.5(3.9±1.5)ml.The rate of local control at 3 months, 6 months, 12 months and ≥18 months after PVP was respectively 98.9%, 95.1%, 91.8%, and 85.2%, the difference was statistically significant(all P<0.05). The local control rate showed a statistically significant relationship to the groups with the rate of cement filling at 6 months, 12 months and ≥18 months after PVP, but there was no statistical difference at postoperative 3 months. The rate of local control was higher in 68 patients with lung or gastrointestinal cancer than in 17 patients with liver or kidney cancer at 3 months, 6 months and 12 months, the difference was statistically significant (P<0.05). Conclusion: Cement augmentation has a local anti-tumor effect on vertebral osteolytic metastatic lesion, and the anti-tumor effect will decrease as the follow-up time extended.

NSG2 (ORF19.273) Encoding Protein Controls Sensitivity of Candida albicans to Azoles through Regulating the Synthesis of C14-Methylated Sterols

Antifungal azole drugs inhibit the synthesis of ergosterol and cause the accumulation of sterols containing a 14α-methyl group, which is related to the properties of cell membrane. Due to the frequent recurrence of fungal infections and clinical long-term prophylaxis, azole resistance is increasing rapidly. In our research, Nsg2p, encoded by the ORF19.273 in Candida albicans, is found to be involved in the inhibition of 14α-methylated sterols and resistance to azoles. Under the action of fluconazole, nsg2Δ/Δ mutants are seriously damaged in the integrity and functions of cell membranes with a decrease of ergosterol ratio and an increase of both obtusifoliol and 14α-methylfecosterol ratio. The balance between ergosterol and 14α-methyl sterols mediated by NSG2 plays an important role in C. albicans responding to azoles in vitro as well as in vivo. These phenotypes are completely different from those of Nsg2p in Saccharomyces cerevisiae, which is proved to increase the stability of HMG-CoA and resistance to lovastatin. Based on the evidence above, it is indicated that the decrease of 14α-methylated sterols is an azole-resistant mechanism in C. albicans, which may provide new strategies for overcoming the problems of azole resistance.

Branches of the NF-κB signaling pathway regulate proliferation of oval cells in rat liver regeneration

The NF-kB (nuclear factor kB) pathway is involved in the proliferation of many cell types. To explore the mechanism of the NF-kB signaling pathway underlying the oval cell proliferation during rat liver regeneration, the Rat Genome 230 2.0 Array was used to detect expression changes of NF-kB signaling pathway-related genes in oval cells. The results revealed that the expression levels of many genes in the NF-kB pathway were significantly changed. This included 48 known genes and 16 homologous genes, as well as 370 genes and 85 homologous genes related to cell proliferation. To further understand the biological significance of these changes, an expression profile function was used to analyze the potential biological processes. The results showed that the NF-kB pathway promoted oval cell proliferation mainly through three signaling branches; the tumor necrosis factor alpha branch (TNF-a pathway), the growth factor branch, and the chemokine branch. An integrated statistics method was used to define the key genes in the NF-kB pathway. Seven genes were identified to play vital roles in the NF-kB pathway. To confirm these results, the protein content, including two key genes (TNF and FGF11) and two non-key genes (CCL2 and TNFRSF12A), were analyzed using two-dimensional gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The results were generally consistent with those of the array data. To conclude, three branches and seven key genes were involved in the NF-kB signaling pathway that regulates oval cell proliferation during rat liver regeneration.

Real-time detection of dental calculus by blue-LED-induced fluorescence spectroscopy

Successful periodontal therapy requires sensitive techniques to discriminate dental calculus from healthy teeth. The aim of the present study was to develop a fluorescence-based procedure to enable real-time detection and quantification of dental calculus. Thirty human teeth--15 teeth with sub- and supragingival calculus and 15 healthy teeth--covered with a layer of physiological saline solution or blood were illuminated by a focused blue LED light source of 405 nm. Autofluorescence spectra recorded along a randomly selected line stretching over the crown-neck-root area of each tooth were utilized to evaluate a so called calculus parameter R, which was selected to define a relationship between the integrated intensities specific for healthy teeth and for calculus in the 477-497 nm (S(A)) and 628-685 nm (S(B)) wavelength regions, respectively. Statistical analysis was performed and a cut-off threshold of R=0.2 was found to distinguish dental calculus from healthy teeth with 100% sensitivity and specificity under various experimental conditions. The results of the spectral evaluation were confirmed by clinical and histological findings. Automated real-time detection and diagnostics for clinical use were implemented by a corresponding software program written in Visual Basic language. The method enables cost-effective and reliable calculus detection, and can be further developed for imaging applications.

[Comparison of hard tissue changes by treatment of angle class II malocclusion with Kloehn's extraoral arch in periods of transitional dentition and permanent tooth]

OBJECTIVE

The optimal treatment period by use of extraoral arch was understood by comparison of the changes of facial hard tissue in treatment of Angle II malocclusion with Kloehn's extraoral arch and Edgwise appliance.

METHODS

A group of 7-8 year old children and a group of 10-11 year-old children were selected, including 16 Angle II malocclusion cases in each group, respectively. Data of cephalograms and model analysis were compared between pretreatment and posttreatment.

RESULTS

The more distance of maxillary molar and more obvious inhibition of maxilla bone growth forward in group of 7-8 year-old children (group of transitional dentition) were detected than that in group of 10-11 year-old children(group of permanent tooth).

CONCLUSION

More effective treatment by use of extraoral arch was detected in the period of transitional dentition than that in permanent tooth.

Memory reprocessing in corticocortical and hippocampocortical neuronal ensembles

Hippocampal cells that fire together during behaviour exhibit enhanced activity correlations during subsequent sleep, with some preservation of temporal order information. Thus, information reflecting experiences during behaviour is re-expressed in hippocampal circuits during subsequent 'offline' periods, as postulated by some theories of memory consolidation. If the hippocampus orchestrates the reinstatement of experience-specific activity patterns in the neocortex, as also postulated by such theories, then correlation patterns both within the neocortex and between hippocampus and neocortex should also re-emerge during sleep. Ensemble recordings were made in the posterior parietal neocortex, in CA1, and simultaneously in both areas, in seven rats. Each session involved an initial sleep episode (S1), behaviour on a simple maze (M), and subsequent sleep (S2). The ensemble activity-correlation structure within and between areas during S2 resembled that of M more closely than did the correlation pattern of S1. Temporal order (i.e. the asymmetry of the cross-correlogram) was also preserved within, but not between, structures. Thus, traces of recent experience are re-expressed in both hippocampal and neocortical circuits during sleep, and the representations in the two areas tend to correspond to the same experience. The poorer preservation of temporal firing biases between neurons in the different regions may reflect the less direct synaptic coupling between regions than within them. Alternatively, it could result from a shift, between behavioural states, in the relative dominance relations in the corticohippocampal dialogue. Between-structure order will be disrupted, for example, if, during behaviour, neocortical patterns tend to drive corresponding hippocampal patterns, whereas during sleep the reverse occurs. This possibility remains to be investigated.

Interactions between location and task affect the spatial and directional firing of hippocampal neurons

When rats forage for randomly dispersed food in a high walled cylinder the firing of their hippocampal "place" cells exhibits little dependence on the direction faced by the rat. On radial arm mazes and similar tasks, place cells are strongly directionally selective within their fields. These tasks differ in several respects, including the visual environment, configuration of the traversable space, motor behavior (e.g., linear and angular velocities), and behavioral context (e.g., presence of specific, consistent goal locations within the environment). The contributions of these factors to spatial and directional tuning of hippocampal neurons was systematically examined in rats performing several tasks in either an enriched or a sparse visual environment, and on different apparati. Place fields were more spatially and directionally selective on a radial maze than on an open, circular platform, regardless of the visual environment. On the platform, fields were more directional when the rat searched for food at fixed locations, in a stereotypic and directed manner, than when the food was scattered randomly. Thus, it seems that place fields are more directional when the animal is planning or following a route between points of special significance. This might be related to the spatial focus of the rat's attention (e.g., a particular reference point). Changing the behavioral task was also accompanied by a change in firing location in about one-third of the cells. Thus, hippocampal neuronal activity appears to encode a complex interaction between locations, their significance and the behaviors the rat is called upon to execute.