EFFECT OF SEMEN EXTENDER SUPPLEMENTATION WITH TREHALOSE，VITAMIN C AND E ON POST-THAW MIN PIG SPERM QUALITIES

BACKGROUND

Cryopreservation of min pig sperm offers an effective method to protect this valuable genetic resource.

OBJECTIVE

To determine whether the extender supplementation with some antioxidants is able to improve the quality of post-thawed sperm of min pig.

MATERIALS AND METHODS

Ejaculated min pig sperm frozen in lactose-egg yolk (LEY) extender supplemented with trehalose, vitamin C and/or water-soluble vitamin E were thawed, and the quality of sperm samples were evaluated.

RESULTS

The quality of post-thawed sperm samples was higher in the groups with supplementation than that of the control group (P < 0.05). Furthermore, the addition of 100 mM trehalose and 25 mM water-soluble vitamin E to the freezing extender strongly preserved the quality of the sperm (P < 0.05).

CONCLUSION

Trehalose and water-soluble vitamin E in the freezing extender effectively improved post-thaw qualities of min pig sperm.

Fate and Phytotoxicity of CeO2 Nanoparticles on Lettuce Cultured in the Potting Soil Environment

Cerium oxide nanoparticles (CeO2 NPs) have been shown to have significant interactions in plants. Previous study reported the specific-species phytotoxicity of CeO2 NPs by lettuce (Lactuca sativa), but their physiological impacts and vivo biotransformation are not yet well understood, especially in relative realistic environment. Butterhead lettuce were germinated and grown in potting soil for 30 days cultivation with treatments of 0, 50, 100, 1000 mg CeO2 NPs per kg soil. Results showed that lettuce in 100 mg·kg-1 treated groups grew significantly faster than others, but significantly increased nitrate content. The lower concentrations treatment had no impact on plant growth, compared with the control. However, the higher concentration treatment significantly deterred plant growth and biomass production. The stress response of lettuce plants, such as Superoxide dismutase (SOD), Peroxidase (POD), Malondialdehyde(MDA) activity was disrupted by 1000 mg·kg-1 CeO2 NPs treatment. In addition, the presence of Ce (III) in the roots of butterhead lettuce explained the reason of CeO2 NPs phytotoxicity. These findings demonstrate CeO2 NPs modification of nutritional quality, antioxidant defense system, the possible transfer into the food chain and biotransformation in vivo.

Growth Factor FGF2 Cooperates with Interleukin-17 to Repair Intestinal Epithelial Damage

The intestinal epithelial barrier plays a critical role in the mucosal immunity. However, it remains largely unknown how the epithelial barrier is maintained after damage. Here we show that growth factor FGF2 synergized with interleukin-17 (IL-17) to induce genes for repairing of damaged epithelium. FGF2 or IL-17 deficiency resulted in impaired epithelial proliferation, increased pro-inflammatory microbiota outgrowth, and consequently worse pathology in a DSS-induced colitis model. The dysregulated microbiota in the model induced transforming growth factor beta 1 (TGFβ1) expression, which in turn induced FGF2 expression mainly in regulatory T cells. Act1, an essential adaptor in IL-17 signaling, suppressed FGF2-induced ERK activation through binding to adaptor molecule GRB2 to interfere with its association with guanine nucleotide exchange factor SOS1. Act1 preferentially bound to IL-17 receptor complex, releasing its suppressive effect on FGF2 signaling. Thus, microbiota-driven FGF2 and IL-17 cooperate to repair the damaged intestinal epithelium through Act1-mediated direct signaling cross-talk.

Photothrombosis combined with thrombin injection establishes a rat model of cerebral venous sinus thrombosis

OBJECTIVE

Cerebral venous sinus thrombosis (CVST) is a rare but life-threatening disease and an animal model for in-depth study of CVST is needed. This study aimed to develop a rat model suitable for studying clinically relevant aspects of CVST and investigating its dynamic pathophysiological changes during a 7-day period.

METHOD

A photothrombosis method was used to create a rat sinus-vein thrombosis model. A spot size-adjustable Diode Pumped Solid State laser (DPSS) combined with thrombin injection occluded the rostral and caudal superior sagittal sinus (SSS). The model was used to evaluate pathophysiological changes at different time points over 7 days. Evans Blue dye injection was used to detect alterations in blood-brain barrier (BBB) permeability. Brain water content was also measured. Moreover, we examined changes in brain infarct volume, neurological function, as well as histology after induction of CVST.

RESULT

CVST in rats significantly altered BBB permeability, consistent with the development of brain edema. It was accompanied by an increase in brain infarct volume and deficits in neurological function that began on day 1, peaked on day 2, and typically improved by day 7 due to the neuroprotective effects of angiogenesis and gliocyte proliferation.

CONCLUSION

In this study, we describe a rat model that produces clinically relevant pathophysiology and pathology that will facilitate evaluation of therapeutic regimens for CVST. Furthermore, our results indicate a period of optimal clinical intervention for patients with CVST, which may reduce the probability of dependency and death.

Nomogram for Predicting Time to Death After Withdrawal of Life-Sustaining Treatment in Patients With Devastating Neurological Injury

Reliable prediction of time of death after withdrawal of life-sustaining treatment in patients with devastating neurological injury is crucial to successful donation after cardiac death. Herein, we conducted a study of 419 neurocritical patients who underwent life support withdrawal at four neurosurgical centers in China. Based on a retrospective cohort, we used multivariate Cox regression analysis to identify prognostic factors for patient death, which were then integrated into a nomogram. The model was calibrated and validated using data from an external retrospective cohort and a prospective cohort. We identified 10 variables that were incorporated into a nomogram. The C-indexes for predicting the 60-min death probability in the training, external validation and prospective validation cohorts were 0.96 (0.93-0.98), 0.94 (0.91-0.97), and 0.99 (0.97-1.00), respectively. The calibration plots after WLST showed an optimal agreement between the prediction of time to death by the nomogram and the actual observation for all cohorts. Then we identified 22, 26 and 37 as cut-points for risk stratification into four groups. Kaplan-Meier curves indicated distinct prognoses between patients in the different risk groups (p < 0.001). In conclusion, we have developed and validated a nomogram to accurately identify potential cardiac death donors in neurocritical patients in a Chinese population.

TRIM35 Interacts with pyruvate kinase isoform M2 to suppress the Warburg effect and tumorigenicity in hepatocellular carcinoma

Tripartite motif-containing protein 35 (TRIM35) is a member of RBCC family, which has a highly conserved order consisting of a RING domain followed by one or two B-Box domains and then a coiled-coil domain. We previously identified TRIM35 as a novel tumor suppressor in human hepatocellular carcinoma (HCC). However, the molecular mechanism that TRIM35 uses to suppress tumorigenicity is largely unknown. Pyruvate kinase isoform M2 (PKM2) has been demonstrated to have a central role in metabolic reprogramming during cancer progression. Phosphorylation of PKM2 tyrosine residue 105 (Y105) regulates PKM2 to provide a metabolic advantage to tumor cells, thereby promoting tumor growth. In the present work, mass spectrometry analysis demonstrated an interaction between TRIM35 and PKM2. Co-IP experiments confirmed that TRIM35 interacts with PKM2 and that the coiled-coil domain is required for such an interaction. Furthermore, the coiled-coil domain mediates decreases in the Warburg effect and in the cell proliferation of HCC cells. In addition, TRIM35 suppresses the tumorigenicity of HCC cells through the blockade of PKM2 Y105 phosphorylation. Collectively, our data reveal a new function for TRIM35, which is to regulate the Warburg effect and tumorigenicity through interaction with PKM2 in HCC.

Cellular Components Mediating Coadherence of Candida albicans and Fusobacterium nucleatum

Candida albicans is an opportunistic fungal pathogen found as part of the normal oral flora. It can be coisolated with Fusobacterium nucleatum, an opportunistic bacterial pathogen, from oral disease sites, such as those involved in refractory periodontitis and pulp necrosis. The physical coadherence between these 2 clinically important microbes has been well documented and suggested to play a role in facilitating their oral colonization and colocalization and contributing to polymicrobial pathogenesis. Previous studies indicated that the physical interaction between C. albicans and F. nucleatum was mediated by the carbohydrate components on the surface of C. albicans and the protein components on the Fusobaterium cell surface. However, the identities of the components involved still remain elusive. This study was aimed at identifying the genetic determinants involved in coaggregation between the 2 species. By screening a C. albicans SN152 mutant library and a panel of F. nucleatum 23726 outer membrane protein mutants, we identified FLO9, which encodes a putative adhesin-like cell wall mannoprotein of C. albicans and radD, an arginine-inhibitable adhesin-encoding gene in F. nucleatum that is involved in interspecies coadherence. Consistent with these findings, we demonstrated that the strong coaggregation between wild-type F. nucleatum 23726 and C. albicans SN152 in an in vitro assay could be greatly inhibited by arginine and mannose. Our study also suggested a complex multifaceted mechanism underlying physical interaction between C. albicans and F. nucleatum and for the first time revealed the identity of major genetic components involved in mediating the coaggregation. These observations provide useful knowledge for developing new targeted treatments for disrupting interactions between these 2 clinically relevant pathogens.

Relationship between genetic polymorphisms of DNA ligase 1 and non-small cell lung cancer susceptibility and radiosensitivity

The aim of this study was to examine the relationship between genetic polymorphisms in DNA ligase 1 (LIG1) and non-small cell lung cancer (NSCLC) susceptibility and radiosensitivity in a Chinese population. This was a case-control study that included 352 NSCLC patients and 448 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism analysis was conducted to detect HaeIII polymorphisms in exon 6 of the LIG1 gene in this popula-tion. This information was used to observe the effects of radiation in pa-tients with different genotypes in order to determine the genotypes as-sociated with radiosensitivity. The CC genotype and C allele frequency were significantly higher in the NSCLC group than in the control group (P = 0.012 and P = 0.023, respectively). The relative risk of experienc-ing NSCLC was 2.55 [95% confidence interval (CI), 1.12-3.98] for CC homozygous patients and 0.87 (95%CI, 0.46-1.88) for AA homozygous patients. Analysis of LIG1 genetic polymorphisms and radiosensitiv-ity of NSCLC patients showed that AA homozygous patients were sig-nificantly more radiosensitive than the control group (AA vs AC, P = 0.014; AA vs CC, P < 0.001; AC vs CC, P = 0.023). Therefore, the LIG1 CC genotype was associated with susceptibility to NSCLC, and the AA genotype demonstrated increased radiosensitivity compared to the AC and CC genotypes.

Dissolved effluent organic matter: Characteristics and potential implications in wastewater treatment and reuse applications

Wastewater reuse is currently considered globally as the most critical element of sustainable water management. The dissolved effluent organic matter (dEfOM) present in biologically treated urban wastewater, consists of a heterogeneous mixture of refractory organic compounds with diverse structures and varying origin, including dissolved natural organic matter, soluble microbial products, endocrine disrupting compounds, pharmaceuticals and personal care products residues, disinfection by-products, metabolites/transformation products and others, which can reach the aquatic environment through discharge and reuse applications. dEfOM constitutes the major fraction of the effluent organic matter (EfOM) and due to its chemical complexity, it is necessary to utilize a battery of complementary techniques to adequately describe its structural and functional character. dEfOM has been shown to exhibit contrasting effects towards various aquatic organisms. It decreases metal uptake, thus potentially reducing their bioavailability to exposed organisms. On the other hand, dEfOM can be adsorbed on cell membranes inducing toxic effects. This review paper evaluates the performance of various advanced treatment processes (i.e., membrane filtration and separation processes, activated carbon adsorption, ion-exchange resin process, and advanced chemical oxidation processes) in removing dEfOM from wastewater effluents. In general, the literature findings reveal that dEfOM removal by advanced treatment processes depends on the type and the amount of organic compounds present in the aqueous matrix, as well as the operational parameters and the removal mechanisms taking place during the application of each treatment technology.

Ultrasmall [(64)Cu]Cu nanoclusters for targeting orthotopic lung tumors using accurate positron emission tomography imaging

Positron emission tomography (PET) imaging has received special attention owing to its higher sensitivity, temporal resolution, and unlimited tissue penetration. The development of tracers that target specific molecules is therefore essential for the development and utility of clinically relevant PET procedures. However, (64)Cu as a PET imaging agent generally has been introduced into biomaterials through macrocyclic chelators, which may lead to the misinterpretation of PET imaging results due to the detachment and transchelation of (64)Cu. In this study, we have developed ultrasmall chelator-free radioactive [(64)Cu]Cu nanoclusters using bovine serum albumin (BSA) as a scaffold for PET imaging in an orthotopic lung cancer model. We preconjugated the tumor target peptide luteinizing hormone releasing hormone (LHRH) to BSA molecules to prepare [(64)Cu]CuNC@BSA-LHRH. The prepared [(64)Cu]Cu nanoclusters showed high radiolabeling stability, ultrasmall size, and rapid deposition and diffusion into tumor, as well as predominantly renal clearance. [(64)Cu]CuNC@BSA-LHRH showed 4 times higher tumor uptake compared with that of [(64)Cu]CuNC@BSA by analyzing the (64)Cu radioactivity of tissues via gamma counting. The PET imaging using [(64)Cu]Cu nanoclusters as tracers showed more sensitive, accurate, and deep penetration imaging of orthotopic lung cancer in vivo compared with near-infrared fluorescence imaging. The nanoclusters provide biomedical research tools for PET molecular imaging.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

Correction of erroneously packed protein's side chains in the NMR structure based on ab initio chemical shift calculations

In this work, protein side chain (1)H chemical shifts are used as probes to detect and correct side-chain packing errors in protein's NMR structures through structural refinement. By applying the automated fragmentation quantum mechanics/molecular mechanics (AF-QM/MM) method for ab initio calculation of chemical shifts, incorrect side chain packing was detected in the NMR structures of the Pin1 WW domain. The NMR structure is then refined by using molecular dynamics simulation and the polarized protein-specific charge (PPC) model. The computationally refined structure of the Pin1 WW domain is in excellent agreement with the corresponding X-ray structure. In particular, the use of the PPC model yields a more accurate structure than that using the standard (nonpolarizable) force field. For comparison, some of the widely used empirical models for chemical shift calculations are unable to correctly describe the relationship between the particular proton chemical shift and protein structures. The AF-QM/MM method can be used as a powerful tool for protein NMR structure validation and structural flaw detection.

Peptide sequence determinants in HLA-DM susceptibility (APP5P.105)

HLA-DM catalyzes peptide exchange reactions in MHCII molecules. DM functions by accelerating the peptide loading process and editing the epitopes that are presented to CD4 T cells. The catalytic potency of DM differs by MHCII-peptide complex such that some are variably edited while others are immutable. To date, the catalytic mechanism and peptide sequence determinants of susceptibility to DM editing remain unresolved. In this study, we use an FP assay to measure the effect of DM on the binding kinetics of HLA-DR1 to peptides with anchor residues of neutral, disfavored, or favored amino acids. We provide evidence for a model in which the peptide sequence determines the “effective affinity” of an MHCII-peptide complex for DM and specifies DM catalytic potency. Our results support a mechanism whereby interactions between peptide and MHC regions far from the DM contact interface can alter the effective binding affinity of the complex. We show that the peptide P1 anchor impacts kcat, which implies that the peptide N-terminus may occupy the binding groove in the “functional” catalytic complex. We show that association rates are not sensitive to peptide sequence, indicating that DM has little effect on the association of peptide to empty class II molecules. Together, these findings provide insight into the DM catalytic mechanism and suggest that stable interactions with DM at the contact surface are linked to unstable interactions in the peptide-binding groove and vice versa.

Peptidomic analysis of type-1 diabetes associated HLA-DQ molecules and impact of HLA-DM editing (APP5P.108)

HLA-DM is critical in editing peptide repertoires presented by APC, thus influencing the selection/activation of CD4+ T cells. We previously reported that type-1 diabetes (T1D) associated HLA-DQ2, 8 & DQ2/8 molecules (DQs) are relatively resistant to DM editing of the CLIP peptides. In this study, we further studied DM sensitivity of T1D-associated DQs by peptidomic analysis. Compared to a T1D-protective DQ6, the percentages of shared peptides among T1D-associated DQs were significantly higher. There were greater numbers of nested peptide sets and long peptides (&gt;20 aa) eluted from T1D-associated DQs. Predicted peptide binding motifs of DQ2, 8 & 2/8 shared charged anchor residues, while hydrophobic anchors were present in DQ6 peptides. Competition binding assays comparing the eluted peptides from DM sensitive, dependent, or resistant groups showed that the binding affinities of the DM sensitive peptides were significantly lower than that of CLIP1 peptide. The increased sDQ8-CLIP1 complex stability, with the intrinsic half-life of 58 h measured by fluorescence polarization assay, was 8 times longer than that of sDQ6-CLIP1 (7 h), further supporting the DM resistance of T1D associated DQs. Collectively, T1D associated DQs share distinct characteristics, including binding of peptides from known T1D auto-antigens. Our new data further support the hypothesis that DM resistance in T1D associated DQs affects the peptide repertoires, thus contributing to the pathogenesis of T1D.

Quantum calculation of protein NMR chemical shifts based on the automated fragmentation method

The performance of quantum mechanical methods on the calculation of protein NMR chemical shifts is reviewed based on the recently developed automatic fragmentation quantum mechanics/molecular mechanics (AF-QM/MM) approach. By using the Poisson-Boltzmann (PB) model and first solvation water molecules, the influence of solvent effect is also discussed. Benefiting from the fragmentation algorithm, the AF-QM/MM approach is computationally efficient, linear-scaling with a low pre-factor, and thus can be applied to routinely calculate the ab initio NMR chemical shifts for proteins of any size. The results calculated using Density Functional Theory (DFT) show that when the solvent effect is included, this method can accurately reproduce the experimental ¹H NMR chemical shifts, while the ¹³C NMR chemical shifts are less affected by the solvent. However, although the inclusion of solvent effect shows significant improvement for ¹⁵N chemical shifts, the calculated values still have large deviations from the experimental observations. Our study further demonstrates that AF-QM/MM calculated results accurately reflect the dependence of ¹³C(α) NMR chemical shifts on the secondary structure of proteins, and the calculated ¹H chemical shift can be utilized to discriminate the native structure of proteins from decoys.

Histone deacetylase inhibitors prevent activation-induced cell death and promote anti-tumor immunity

The poor efficacy of the in vivo anti-tumor immune response has been partially attributed to ineffective T-cell responses mounted against the tumor. Fas-FasL-dependent activation-induced cell death (AICD) of T cells is believed to be a major contributor to compromised anti-tumor immunity. The molecular mechanisms of AICD are well-investigated, yet the possibility of regulating AICD for cancer therapy remains to be explored. In this study, we show that histone deacetylase inhibitors (HDACIs) can inhibit apoptosis of CD4⁺ T cells within the tumor, thereby enhancing anti-tumor immune responses and suppressing melanoma growth. This inhibitory effect is specific for AICD through suppressing NFAT1-regulated FasL expression on activated CD4⁺ T cells. In gld/gld mice with mutation in FasL, the beneficial effect of HDACIs on AICD of infiltrating CD4⁺ T cells is not seen, confirming the critical role of FasL regulation in the anti-tumor effect of HDACIs. Importantly, we found that the co-administration of HDACIs and anti-CTLA4 could further enhance the infiltration of CD4⁺ T cells and achieve a synergistic therapeutic effect on tumor. Therefore, our study demonstrates that the modulation of AICD of tumor-infiltrating CD4⁺ T cells using HDACIs can enhance anti-tumor immune responses, uncovering a novel mechanism underlying the anti-tumor effect of HDACIs.

Transformation of ceria nanoparticles in cucumber plants is influenced by phosphate

Transformation is a critical factor that affects the fate and toxicity of manufactured nanoparticles (NPs) in the environment and living organisms. This paper aims to investigate the effect of phosphate on the transformation of CeO2 NPs in hydroponic plants. Cucumber seedlings were treated with 2000 mg/L CeO2 NPs in nutrient solutions with or without adding phosphate (+P or -P) for 3 weeks. Large quantities of needle-like CePO4 was found outside the epidermis in the +P group. While in the -P group, CePO4 only existed in the intercellular spaces and vacuole of root cells. X-ray absorption near edge spectroscopy (XANES) indicates that content and percentage of Ce-carboxylates in the shoots of -P group (418 mg/kg, 67.5%) were much higher than those in the +P group (30.1 mg/kg, 21%). The results suggest that phosphate might influence the transformation process of CeO2 NPs in plants and subsequently their ultimate fate in the ecosystem.

ACK1 promotes hepatocellular carcinoma progression via downregulating WWOX and activating AKT signaling

Several studies have revealed that ACK1 is upregulated in various cancers and promotes tumor progression. However, the role and mechanism of ACK1 in hepatocellular carcinoma (HCC) remains unknown. In this study, the expression of ACK1 was assessed in several cell lines and 150 pairs of HCC and adjacent noncancerous liver tissues. The protein expression of p-ACK1 and WWOX were detected by immunohistochemistry to evaluate their correlation with ACK1. Flow cytometry, caspase 3/7 activity assay, BrdU cell proliferation assay, MTT assay and Transwell assay were used to detect apoptosis, proliferation, invasion and migration of HCC cells. The regulatory effect of ACK1 on WWOX, AKT, p-AKT, MMP2 and MMP9 in HCC cells was confirmed by immuno-blotting. We found that ACK1 was more highly expressed in HCC tissues than in non-HCC tissues, and over-expression of ACK1 was correlated with clinicopathological features of poor prognosis. Clinical analysis demonstrated that ACK1 is an independent prognostic marker for predicting overall survival and disease-free survival of HCC patients. Pearson's correlation coefficient analysis indicated that ACK1 was positively associated with p-ACK1 and was negatively associated with WWOX expression. In vitro studies showed that knockdown of ACK1 promoted HCC cell apoptosis and repressed HCC cells invasion, migration and proliferation. Furthermore, knockdown of ACK1 resulted in upregulation of WWOX and inactivation of AKT signaling. In this study, we also found that knockdown of ACK1 resulted in the downregulation of MMP2 and MMP9 in HCC. Our results indicate that ACK1 is an independent prognostic marker and promotes HCC progression via downregulating WWOX and activating AKT signaling.

Species-specific toxicity of ceria nanoparticles to Lactuca plants

Species-specific differences in the toxicity of manufactured nanoparticles (MNPs) have been reported, but the underlying mechanisms are unknown. We previously found that CeO2 NPs inhibited root elongation of head lettuce, whereas no toxic effect was observed on other plants (such as wheat, cucumber and radish). In this study, interactions between Lactuca plants and three types of CeO2 NPs (lab-synthesized 7 and 25 nm CeO2 NPs, and a commercial CeO2 NPs) were investigated. It was found that CeO2 NPs were toxic to three kinds of Lactuca genus plants and different CeO2 NPs showed different degrees of toxicity. The results of X-ray absorption near edge fine structure indicate that small parts of CeO2 NPs were transformed from Ce(IV) to Ce(III) in roots of the plants that were treated with CeO2 NPs during the seed germination stage. But the high sensitivity of Lactuca plants to the released Ce(3+) ions caused the species-specific phytotoxicity of CeO2 NPs. Differences in sizes and zeta potentials among three types of CeO2 NPs resulted in their different degrees of biotransformation which accounted for the discrepancy in the toxicity to Lactuca plants. This study is among the few, and may indeed the first, that addresses the relation between the physicochemical properties of nanoparticles and its species-specific phytotoxicity.