Effects of temperature, pH, and relative humidity on the growth of Penicillium paneum OM1 isolated from pears and its patulin production.

Patulin is a mycotoxin produced by several species of Penicillium sp., Aspergillus sp., and Byssochlamys sp. on apples and pears. Most studies have been focused on Penicillium expansum, a common postharvest pathogen, but little is known about the characteristics of Penicillium paneum. In the present study, we evaluated the effects of temperature, pH, and relative humidity (RH) on the growth of P. paneum OM1, which was isolated from pears, and its patulin production. The fungal strain showed the highest growth rate at 25 °C and pH 4.5 on pear puree agar medium (PPAM) under 97 % RH, while it produced the highest amount of patulin at 20 °C and pH 4.5 on PPAM under 97 % RH. Moreover, RT-qPCR analysis of relative expression levels of 5 patulin biosynthetic genes (patA, patE, patK, patL, and patN) in P. paneum OM1 exhibited that the expression of the 4 patulin biosynthetic genes except patL was up-regulated in YES medium (patulin conducive), while it was not in PDB medium (patulin non-conducive). Our data demonstrated that the 3 major environmental parameters had significant impact on the growth of P. paneum OM1 and its patulin production. These results could be exploited to prevent patulin contamination by P. paneum OM1 during pear storage.

Two cooperative binding sites sensitize PI(4,5)P2 recognition by the tubby domain.

Phosphoinositides (PIs) are lipid signaling molecules that operate by recruiting proteins to cellular membranes via PI recognition domains. The dominant PI of the plasma membrane is phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. One of only two PI(4,5)P2 recognition domains characterized in detail is the tubby domain. It is essential for targeting proteins into cilia involving reversible membrane association. However, the PI(4,5)P2 binding properties of tubby domains have remained enigmatic. Here, we used coarse-grained molecular dynamics simulations to explore PI(4,5)P2 binding by the prototypic tubby domain. The comparatively low PI(4,5)P2 affinity of the previously described canonical binding site is underpinned in a cooperative manner by a previously unknown, adjacent second binding site. Mutations in the previously unknown site impaired PI(4,5)P2-dependent plasma membrane localization in living cells and PI(4,5)P2 interaction in silico, emphasizing its importance for PI(4,5)P2 affinity. The two-ligand binding mode may serve to sharpen the membrane association-dissociation cycle of tubby-like proteins that underlies delivery of ciliary cargo.

Stability and bifurcation control analysis of a delayed fractional-order eco-epidemiological system.

Considering the factor of artificial intervention in biological control, a delayed fractional eco-epidemiological system with an extended feedback controller is proposed. By using the digestion delay as bifurcation parameter, the stability and Hopf bifurcation are investigated, and the branching conditions are given. The system undergoes Hopf bifurcation, when the parameter τ passes through the critical value. In addition, it can be pointed out that the negative feedback gain and the feedback delay could affect the bifurcation critical value of the system. Therefore, the Hopf bifurcation can also be induced by taking the feedback delay as a bifurcation parameter. Finally, by plotting the solution curve of the system, the significance of the controller to the stability of the eco-epidemiological system is verified.

Constructing zigzag-like hollow mesoporous nanospheres MoO2/C with superior lithium storage performance.

Hollow mesoporous nanospheres MoO2/C are successfully constructed through metal chelating reaction between molybdenum acetylacetone and glycerol as well as the Kirkendall effect induced by diammonium hydrogen phosphate. MoO2nanoparticles coupled by amorphous carbon are assembled to unique zigzag-like hollow mesoporous nanosphere with large specific surface area of 147.7 m2g-1and main pore size of 8.7 nm. The content of carbon is 9.1%. As anode material for lithium-ion batteries, the composite shows high specific capacity and excellent cycling performance. At 0.2 A g-1, average discharge capacity stabilizes at 1092 mAh g-1. At 1 A g-1after 700 cycles, the discharge capacity still reaches 512 mAh g-1. Impressively, the composite preserves intact after 700 cycles. Even at 5 A g-1, the discharge capacity can reach 321 mAh g-1, exhibiting superior rate capability. Various kinetics analyses demonstrate that in electrochemical reaction, the proportion of the surface capacitive effect is higher, and the composite has relatively high diffusion coefficient of Li ions and fast faradic reaction kinetics. Excellent lithium storge performance is attributed to the synergistic effect of zigzag-like hollow mesoporous nanosphere and amorphous carbon, which improves reaction kinetics, structure stability and electronic conductivity of MoO2. The present work provides a new useful structure design strategy for advanced energy storage application of MoO2.

Deterministic and stochastic dynamics of a modified Leslie-Gower prey-predator system with simplified Holling-type â £ scheme.

In this paper, a prey-predator model with modified Leslie-Gower and simplified Holling-type Ⅳ functional responses is proposed to study the dynamic behaviors. For the deterministic system, we analyze the permanence of the system and the stability of the positive equilibrium point. For the stochastic system, we not only prove the existence and uniqueness of global positive solution, but also discuss the persistence in mean and extinction of the populations. In addition, we find that stochastic system has an ergodic stationary distribution under some parameter constraints. Finally, our theoretical results are verified by numerical simulations.

Orphan G Protein-Coupled Receptor GPRC5B Controls Smooth Muscle Contractility and Differentiation by Inhibiting Prostacyclin Receptor Signaling.

BACKGROUND: G protein-coupled receptors are important regulators of contractility and differentiation in vascular smooth muscle cells (SMCs), but the specific function of SMC-expressed orphan G protein-coupled receptor class C group 5 member B (GPRC5B) is unclear. METHODS: We studied the role of GPRC5B in the regulation of contractility and dedifferentiation in human and murine SMCs in vitro and in iSM-Gprc5b-KO (tamoxifen-inducible, SMC-specific knockout) mice under conditions of arterial hypertension and atherosclerosis in vivo. RESULTS: Mesenteric arteries from SMC-specific Gprc5b-KOs showed ex vivo significantly enhanced prostacyclin receptor (IP)-dependent relaxation, whereas responses to other relaxant or contractile factors were normal. In vitro, knockdown of GPRC5B in human aortic SMCs resulted in increased IP-dependent cAMP production and consecutive facilitation of SMC relaxation. In line with this facilitation of IP-mediated relaxation, iSM-Gprc5b-KO mice were protected from arterial hypertension, and this protective effect was abrogated by IP antagonists. Mechanistically, we show that knockdown of GPRC5B increased the membrane localization of IP both in vitro and in vivo and that GPRC5B, but not other G protein-coupled receptors, physically interacts with IP. Last, we show that enhanced IP signaling in GPRC5B-deficient SMCs not only facilitates relaxation but also prevents dedifferentiation during atherosclerosis development, resulting in reduced plaque load and increased differentiation of SMCs in the fibrous cap. CONCLUSIONS: Taken together, our data show that GPRC5B regulates vascular SMC tone and differentiation by negatively regulating IP signaling.

Transurethral endoscopic submucosal en bloc dissection for nonmuscle invasive bladder cancer: A comparison study of HybridKnife-assisted versus conventional dissection technique.

SUBJECTS: The aim of this study is to compare the efficacy and safety of en bloc bladder tumor-endoscopic submucosal dissection (BT-ESD) and conventional transurethral resection of BT (TURBT) in nonmuscle invasive bladder cancer (NMIBC) patients. METHODS: A retrospective cohort study was carried out in Shaanxi Provincial People's Hospital. A total of 193 eligible NMIBC (Ta/T1) patients were enrolled in this study (95 cases in BT-ESD group and 98 cases in TURBT group), between November 2013 and January 2017. The operation time, blood loss, postoperative bladder irrigation time, catheter indwelling time, hospital stay time, and complications were compared. Data were presented as median (range). Chi-squared or rank-sum test, two-way ANOVA, and Mantel-Cox (Log-Rank) test were performed using statistical software. A threshold of P < 0.05 was defined as statistically significant. RESULTS: The average operation time in the BT-ESD group was longer than that of in the TURBT group (40.0 [5.0, 100.0] min vs. 19.5 [3.0, 55.5] min); however, no significant longer operating time (P < 0.05) were observed in the smaller tumor (0 cm-3 cm). The postoperative bladder irrigation time, catheter indwelling time, and hospital stay in BT-ESD group were significantly shorter than that of in TURBT group (9.0 [5.0, 18.0] h, 2.5 [1.0, 4.0] d and 3.5 [2.0, 5.0] d for BT-ESD; 18.0 [12.0, 48.0] h, 3.5 [2.0, 7.0] d, and 4.5 [3.0, 8.0] d for TURBT). In addition, the BT-ESD group showed the decreased overall incidence of complications (2.1% vs. 9.2%). The univariate and multivariate analyses indicated an association between surgical option and tumor recurrence (hazard ratio = 5.624, odds ratio = 95% confidence interval = 1.582-19.991), Kaplan-Meir analysis showed significant difference in recurrence-free survival (RFS) (94.7% for ESD group vs. 78.4% for TURBT group) at 33 months. CONCLUSIONS: The application of the HybridKnife lead to a decrease in complications and RFS rate, which was a more safe and effective approach for NMIBC than conventional TURBT.

Silibinin suppresses bladder cancer cell malignancy and chemoresistance in an NF-κB signal-dependent and signal-independent manner.

Because bladder cancer (BCa) is the 9th most common malignant tumor and 13th leading cause of death due to cancer, therapeutic approaches have attracted a great deal of attention from both clinicians and BCa patients. Although the development of surgery and targeted drugs has brought new challenges for the traditional concept of BCa therapy, various types of chemotherapy remain the final treatment method for many BCa patients. However, chemoresistance inevitably appears, leading to the failure of chemotherapy. Silibinin, a polyphenolic flavonoid component isolated from the fruits or seeds of milk thistle, has been reported to play important roles in inhibiting tumor chemoresistance in breast cancer and head and neck squamous cell carcinomas. Our previous study indicated that silibinin inhibited BCa progression in some mechanisms but with no conclusion of chemoresistance inhibition. Therefore, in the present study, we dissected the role of silibinin in BCa progression and chemoresistance. Our results revealed that in BCa, chemodrug-induced chemoresistance was reversed in the presence of silibinin. Further mechanistic study indicated that silibinin suppressed chemoresistance and BCa malignancy in an NF-κB-dependent and -independent manner. In addition, all of the inhibitory effects were dose­dependent. Thus, our results provide a potential use for silibinin in BCa therapeutics.

SPOP promotes tumor progression via activation of ß-catenin/TCF4 complex in clear cell renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of kidney cancer, about one third of the cases are diagnosed at advanced stages with metastases and effective treatments for metastatic RCC are lacking. The molecular events supporting RCC progression remain poorly understood. SPOP, an E3 ubiquitin ligase component, was recently showed to sufficiently promote RCC tumorigenesis, however, other potential functions of SPOP in RCC have not been studied. In the present investigation, by assessing the immunohistochemical staining of SPOP in urological tumors, we found the protein was highly expressed in RCC, in particular, it was specifically expressed in clear cell RCC. cDNA microarray data showed that SPOP mRNA level was significantly increased in clear cell RCC compared to normal kidney tissues, which might be the result of the abnormal DNA copy number of this gene. More interestingly, SPOP was positive in tumors with local invasion or metastasis, and it was associated with tumor recurrence-free survival of clear cell RCC patients. Further in vitro assays demonstrated that SPOP drove RCC epithelial-mesenchymal transition (EMT) and promoted cell invasion. Mechanistically, SPOP enhanced ß-catenin protein expression as well as its nuclear translocation, and elevated TCF4 expression. Both ß-catenin and TCF4 upregulated the critical EMT-inducing transcription factor ZEB1, which functioned as an effector of ß-catenin/TCF4 signaling in RCC invasion. These data identified SPOP as a new marker and prognostic factor for clear cell RCC, and its functions provide new insight into the molecular mechanisms of RCC progression, in which SPOP appears to be an EMT activator.