Proteomic characteristics of plasma and blood cells in natural aging rhesus monkeys.

Aging has become a serious social issue that places a heavy burden on society. However, the underlying mechanisms of aging remain unclear. This study sought to understand the aging process as it may be affected by proteins in the blood, the most important functional system for material transportation in the body. We analyzed and compared the protein expression spectrums in the blood of old and young rhesus monkeys and found 257 proteins expressed differentially in plasma and 1183 proteins expressed differentially in blood cells. Through bioinformatics analysis, we found that the differentially-expressed proteins in plasma were involved in signal pathways related to complement and coagulation cascades, pertussis, malaria, phagosome, and cholesterol metabolism, while the differentially-expressed proteins in blood cells were involved in endocytosis, proteasome, ribosome, protein processing in the endoplasmic reticulum, and Parkinson's disease. We confirmed that the protein levels of complement C2 in plasma and actin-related protein 2/3 complex subunit 2 (ARPC2) in blood cells obviously decreased, whereas the complement C3 and complement component 4 binding protein beta (C4BPB) significantly increased in plasma of old rhesus monkeys and C57BL/6 mice. Our results suggest that C2, C3, C4BPB, and ARPC2 can be used as target proteins for anti-aging research.

Effect of TDI-Assisted Hydrophobic Surface Modification of Microcrystalline Cellulose on the Tensile Fracture of MCC/PLA Composite, and Estimation of the Degree of Substitution by Linear Regression.

Microcrystalline cellulose (MCC) was modified using toluene-2,4-diisocyanate (TDI) in tetrahydrofuran (THF). The reaction was set up for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 24 h at 75 °C. The study was aimed at hydrophobic modification of microcrystalline cellulose (MCC) to improve its dispersion in PLA matrix. Data from the elemental analysis were used to develop a statistical model to predict the degree of substitution (DS) of the OH on the surface of the MCC using both the water contact angle (WCA) and the time of carbamation as the independent variables. Composite was fabricated at 1%, 2%, 3%, 4%, and 5% fiber loading. Fourier transformed infrared spectroscopy was used to characterize the MCC and to confirm the successful graft of TDI to the MCC surface. The morphology and elemental analysis of the modified samples were examined with SEM-EDX. The samples' wettability was analyzed with a contact angle meter to measure the water contact angle (WCA). The tensile properties of composites were analyzed on a universal testing machine. The result showed that, after 1 h of carbamation, the minimum DS recorded was 0.11, and the maximum DS after 24 h was 0.16. The SEM revealed that the modified MCC had homogeneous dispersion in the polymer matrix. At 3% fiber loading, the tensile strength (TS) and elongation were at a maximum and had improvements of 80.67% and 79.44% as compared to neat PLA. The fractured tensile surface from SEM analysis showed that surface modification enhanced fiber-matrix adhesion and significantly improved the composite's strength and toughness. The proposed model that was developed in this study had a coefficient of determination (R2) of 93% to show that the model has a near-perfect goodness of fit and can well be an effective approach to predict the DS of OH from WCA and the time of reaction at similar or the same reaction conditions.

Rab5, Rab7, and Rab11 Are Required for Caveola-Dependent Endocytosis of Classical Swine Fever Virus in Porcine Alveolar Macrophages.

The members of Flaviviridae utilize several endocytic pathways to enter a variety of host cells. Our previous work showed that classical swine fever virus (CSFV) enters porcine kidney (PK-15) cells through a clathrin-dependent pathway that requires Rab5 and Rab7. The entry mechanism for CSFV into other cell lines remains unclear, for instance, porcine alveolar macrophages (3D4/21 cells). More importantly, the trafficking of CSFV within endosomes controlled by Rab GTPases is unknown in 3D4/21 cells. In this study, entry and postinternalization of CSFV were analyzed using chemical inhibitors, RNA interference, and dominant-negative (DN) mutants. Our data demonstrated that CSFV entry into 3D4/21 cells depends on caveolae, dynamin, and cholesterol but not clathrin or macropinocytosis. The effects of DN mutants and knockdown of four Rab proteins that regulate endosomal trafficking were examined on CSFV infection, respectively. The results showed that Rab5, Rab7, and Rab11, but not Rab9, regulate CSFV endocytosis. Confocal microscopy showed that virus particles colocalize with Rab5, Rab7, or Rab11 within 30 min after virus entry and further with lysosomes, suggesting that after internalization CSFV moves to early, late, and recycling endosomes and then into lysosomes before the release of the viral genome. Our findings provide insights into the life cycle of pestiviruses in macrophages.IMPORTANCE Classical swine fever, is caused by classical swine fever virus (CSFV). The disease is notifiable to World Organisation for Animal Health (OIE) in most countries and causes significant financial losses to the pig industry globally. Understanding the processes of CSFV endocytosis and postinternalization will advance our knowledge of the disease and provide potential novel drug targets against CSFV. With this objective, we used systematic approaches to dissect these processes in CSFV-infected 3D4/21 cells. The data presented here demonstrate for the first time to our knowledge that CSFV is able to enter cells via caveola-mediated endocytosis that requires Rab5, Rab7 and Rab11, in addition to the previously described classical clathrin-dependent pathway that requires Rab5 and Rab7. The characterization of CSFV entry will further promote our current understanding of Pestivirus cellular entry pathways and provide novel targets for antiviral drug development.

Neuronal loss and microgliosis are restricted to the core of Aß deposits in mouse models of Alzheimer's disease.

Amyloid-ß (Aß) deposits, pathologic tau, and neurodegeneration are major pathological hallmarks of Alzheimer's disease (AD). The relationship between neuronal loss and Aß deposits is one of the fundamental questions in the pathogenesis of AD. However, this relationship is controversial. One main reason for the conflicting results may be the confounding effects of pathologic tau, which often coexists with Aß deposits in the brains of AD patients. To clarify the relationship between neuronal loss and Aß deposits, mouse models of AD, which develop abundant Aß deposits in the aged brain without pathologic tau, were used to examine the co-localization of NeuN-positive neurons, NF-H-positive axons, MBP-positive myelin sheaths, and Aß deposits. Neuronal loss, as measured by decreased staining of the neuronal cell body, axon, and myelin sheath, as well as the IBA-1-positive microglia, was significantly increased in the core area of cerebral Aß deposits, but not in adjacent areas. Furthermore, neuronal loss in the core area of cerebral Aß deposits was correlated with Aß deposit size. These results clearly indicate that neuronal loss is restricted to the core of Aß deposits, and this restricted loss probably occurs because the Aß deposit attracts microglia, which cluster in the core area where Aß toxicity and neuroinflammation toxicity are restrained. These findings may contribute to our understanding of the relationship between neuronal loss and Aß deposits in the absence of pathologic tau.

Establishment of a sensitive TaqMan-based real-time PCR assay for porcine circovirus type 3 and its application in retrospective quarantine of imported boars to China.

Porcine circovirus type 3 (PCV3) is a novel pathogen first identified in the United States in 2016. As there is a high possibility that no clinical signs of infection are observed in the host, an accurate and sensitive method is needed for quarantine on numerous live pigs especially for international pig trade. In this study, a TaqMan-based real-time PCR assay specifically for PCV3 was established without cross-reactions with other non-targeted pig viruses. The sensitivity of the current approach is about 1.5 × 101  copies µL-1 plasmid DNA while the sensitivity of the conventional PCR is about 1.5 × 102  copies µL-1 plasmid DNA. Further, this assay was applied in the retrospective quarantine on serum samples of 601 commercial live boars imported to China from the United States, France and the United Kingdom from 2011 to 2017. The results revealed that PCV3 could be detected positive in the commercial boars imported from the United States and the above-mentioned western European countries and phylogenetic study also revealed that viral isolates were grouped with some isolates from Korea and the United States. Our study suggested that PCV3 may be prevalent globally since 2011.