Genome-wide TCP transcription factors analysis provides insight into their new functions in seasonal and diurnal growth rhythm in Pinus tabuliformis

Background Pinus tabuliformis adapts to cold climate with dry winter in northern China, serving as important commercial tree species. The TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTOR family(TCP)transcription factors were found to play a role in the circadian clock system in Arabidopsis. However, the role of TCP transcription factors in P. tabuliformis remains little understood. Results In the present study, 43 TCP genes were identified from P. tabuliformis genome database. Based on the phylogeny tree and sequence similarity, the 43 TCP genes were classified into four groups. The motif results showed that different subfamilies indeed contained different motifs. Clade II genes contain motif 1, clade I genes contain motif 1, 8, 10 and clade III and IV contain more motifs, which is consistent with our grouping results. The structural analysis of PtTCP genes showed that most PtTCPs lacked introns. The distribution of clade I and clade II on the chromosome is relatively scattered, while clade III and clade IV is relatively concentrated. Co-expression network indicated that PtTCP2, PtTCP12, PtTCP36, PtTCP37, PtTCP38, PtTCP41 and PtTCP43 were co-expressed with clock genes in annual cycle and their annual cycle expression profiles both showed obvious seasonal oscillations. PtTCP2, PtTCP12, PtTCP37, PtTCP38, PtTCP40, PtTCP41, PtTCP42 and PtTCP43 were co-expressed with clock genes in diurnal cycle. Only the expression of PtTCP42 showed diurnal oscillation. Conclusions The TCP gene family, especially clade II, may play an important role in the regulation of the season and circadian rhythm of P. tabuliformis. In addition, the low temperature in winter may affect the diurnal oscillations

Impaired Spatial Learning and Memory is Linked to Neurochemical Indicators of Brain Aging in the Middle-Aged CD-1 Mice with Maternal Exposure to LPS

Aim: Prenatal exposure to a disadvantageous circumstance may produce accelerated brain aging. Previously, our middle-aged model of CD-1 mice with maternal exposure to low-dose lipopolysaccharide (LPS) showed accelerated memory aging at a behavioral level. Here we investigated whether there was a corresponding pathophysiological alteration in the brain.Materials and Methods: The mothers in the LPS group were administered a low dose (i.p. 50μg/kg) of LPS daily for 3 days during late gestation to simulate an inflammatory condition in maternal infection.Results: The treatment accelerated the age-related decline of spatial learning and memory in the Morris water maze in the middle-aged offspring. Compared to control mice (n = 12), these mice (n = 12) exhibited elevated malondialdehyde contents (P = 0.042), decreased activities of superoxide dismutase (P < 0.001) and glutathione peroxidase (P = 0.010) in the brain, and elevated levels of amyloid beta (Ps < 0.005) and synaptotagmin-1 (Ps < 0.037) in several hippocampal layers. These age-related indicators correlated with a decline in spatial learning and memory (Ps < 0.05).Conclusions: During gestation, maternal illness in mice might be an initiator of accelerated brain aging in offspring, as indicated by behavioral-cognitive and neurochemical measures

Antigenic analysis of classical swine fever virus E2 glycoprotein using pig antibodies identifies residues contributing to antigenic variation of the vaccine C-strain and group 2 strains circulating in China

BACKGROUND: Glycoprotein E2, the immunodominant protein of classical swine fever virus (CSFV), can induce neutralizing antibodies and confer protective immunity in pigs. Our previous phylogenetic analysis showed that subgroup 2.1 viruses branched away from subgroup 1.1, the vaccine C-strain lineage, and became dominant in China. The E2 glycoproteins of CSFV C-strain and recent subgroup 2.1 field isolates are genetically different. However, it has not been clearly demonstrated how this diversity affects antigenicity of the protein. RESULTS: Antigenic variation of glycoprotein E2 was observed not only between CSFV vaccine C-strain and subgroup 2.1 strains, but also among strains of the same subgroup 2.1 as determined by ELISA-based binding assay using pig antisera to the C-strain and a representative subgroup 2.1 strain QZ-07 currently circulating in China. Antigenic incompatibility of E2 proteins markedly reduced neutralization efficiency against heterologous strains. Single amino acid substitutions of D705N, L709P, G713E, N723S, and S779A on C-strain recombinant E2 (rE2) proteins significantly increased heterologous binding to anti-QZ-07 serum, suggesting that these residues may be responsible for the antigenic variation between the C-strain and subgroup 2.1 strains. Notably, a G713E substitution caused the most dramatic enhancement of binding of the variant C-strain rE2 protein to anti-QZ-07 serum. Multiple sequence alignment revealed that the glutamic acid residue at this position is conserved within group 2 strains, while the glycine residue is invariant among the vaccine strains, highlighting the role of the residue at this position as a major determinant of antigenic variation of E2. A variant Simpson's index analysis showed that both codons and amino acids of the residues contributing to antigenic variation have undergone similar diversification. CONCLUSIONS: These results demonstrate that CSFV vaccine C-strain and group 2 strains circulating in China differ in the antigenicity of their E2 glycoproteins. Systematic site-directed mutagenesis of the antigenic units has revealed residues that limit cross-reactivity. Our findings may be useful for the development of serological differential assays and improvement of immunogenicity of novel classical swine fever vaccines

MCP-1, ICAM-1 and VCAM-1 are present in early aneurysmal dilatation in experimental rats.

Recent studies have suggested that inflammation actively participates in ascending aortic aneurysm formation. The aim of the present study was to evaluate the expression changes of adhesion molecules and MMPs in an experimental model of ascending aortic aneurysm induced by ascending aorta banding in Wistar rats. Twelve rats developed aortic dilation after ascending aorta banding treatment, while nine normal animals underwent surgery without banding were used as controls. Light microscope and scanning electron microscope showed that the wall of the ascending aorta became disorganized as well as infiltration by inflammatory cells in aneurysmal rats. By using immunohistochemical techniques, a significant increase in the immunostaining of MCP-1 was observed in the aneurysmal wall as compared to the normal aortic wall. Under similar experimental conditions, we also found that the immunostaining of ICAM-1 and VCAM-1 was markedly increased in the aneurysmal wall. In addition, gelatin zymographic analysis showed that the expression and activities of MMP-2 and MMP-9 were remarkably enhanced in the ascending aorta of ascending aortic aneurysmal rats as compared to normal rats. These results demonstrate that MCP-1, ICAM-1 and VCAM-1 are involved in the pathogenesis of ascending aortic aneurysm and an increase in the immunostaining and activity of MMP-2 and MMP-9 may promote the progression of ascending aortic aneurysm

Increased Acetylated SNAP25 in the Hippocampus Correlated with Age-Related Deficits in the SAMP8 Mice

Acetylation is an important post-translational modification, which modulates function and localization of cytoplasmic proteins. Synaptosomal-associated protein-25 (SNAP-25) is a presynaptic neurotransmission-regulating protein that can be acetylated. Whether the acetylation level of SNAP25 is affected by aging is unknown. We explored the relative levels of SNAP25 and acetylated SNAP25 in the SAMP8 mice with different ages, and their correlation with spatial cognitive performance in radial six-arm water maze. The SAMP8 mice exhibited decline of spatial learning and memory abilities with aging. The higher hippocampal levels of SNAP25 were found in the 6- and 10-month SAMP8 mice compared to the 2-month mice. The hippocampal level of acetylated SNAP25 in the 10-month mice was higher than those in the 2- and 6-month mice. Positive correlations were found between the age-related increase of SNAP25 and the impairment of spatial learning and memory, and between acetylated SNAP25 level and memory deficits. The results suggested that elevated acetylated SNAP25 during aging might be involved in the age-related memory impairment

Antiatherogenic and Anti-Ischemic Properties of Traditional Chinese Medicine Xinkeshu via Endothelial Protecting Function

Including herbal medicine, complementary and alternative medicine (CAM) is popular worldwide. The traditional Chinese medicine xinkeshu has been widely used to treat coronary heart disease in China. This study was designed to investigate the protective effect and probable mechanism of xinkeshu tablet to atherosclerotic myocardial ischemia rabbit. Rabbits were divided into four groups (n = 12 each) and fed with different diet for 12 weeks: Control (standard diet), Model (high-cholesterol diet), XKS (high-cholesterol diet with 184.8 mg/kg/d xinkeshu), and Atorvastatin (high-cholesterol diet with 5.0 mg/kg/d atorvastatin). Plasma lipoprotein, ECG, endothelium-dependent vessel relaxation, histomorphological study, and expressions of eNOS and VCAM-1 on coronary arteries were assessed. The findings showed that, similar to atorvastatin, xinkeshu presented significant effects on rescuing endothelium-dependent vessel relaxation, inhibiting atherosclerotic progress, preventing myocardial ischemia, and changing eNOS and VCAM-1 expression. However, xinkeshu showed no lipoprotein lowering effect in hypercholesterolemia rabbits. The results of the present study indicated that xinkeshu exerted potent antiatherogenic and anti-ischemic properties on atherosclerotic myocardial ischemia rabbit. An endothelial protecting effect may be involved in the mechanism other than antihyperlipidemic effect

A Novel Contrast-Induced Acute Kidney Injury Model Based on the 5/6-Nephrectomy Rat and Nephrotoxicological Evaluation of Iohexol and Iodixanol In Vivo

Contrast-induced acute kidney injury (CI-AKI) is a serious complication in patients after administration of iodinated contrast media. Proper animal models of CI-AKI can help understand the mechanisms involved and prevent the disorder. We used the 5/6-nephrectomized (NE) rat to develop a CI-AKI model and to evaluate differences in the toxic effects on the kidney between iohexol and iodixanol. We found that six weeks after ablative surgery was the preferred time to induce CI-AKI. We compared multiple pretreatment plans and found that dehydration for 48 hours before iodixanol (320, 10 mL/kg) administration was optimal to induce CI-AKI in the 5/6 NE rats. Compared with iodixanol, iohexol induced a significantly greater reduction in renal function, severe renal tissue damage, intrarenal hypoxia, and apoptotic tubular cells. Iohexol and iodixanol resulted in similarly marked increases in levels of inflammation and oxidative stress. In summary, the 5/6 NE rat combined with dehydration for 48 hours is a useful pretreatment to establish a novel and reliable CI-AKI model. Iohexol induced more severe CI-AKI than iodixanol in this model

Phonon Polaritons in Monolayers of Hexagonal Boron Nitride.

Phonon polaritons in van der Waals materials reveal significant confinement accompanied with long propagation length: important virtues for tasks pertaining to the control of light and energy flow at the nanoscale. While previous studies of phonon polaritons have relied on relatively thick samples, here reported is the first observation of surface phonon polaritons in single atomic layers and bilayers of hexagonal boron nitride (hBN). Using antenna-based near-field microscopy, propagating surface phonon polaritons in mono- and bilayer hBN microcrystals are imaged. Phonon polaritons in monolayer hBN are confined in a volume about one million times smaller than the free-space photons. Both the polariton dispersion and their wavelength-thickness scaling law are altered compared to those of hBN bulk counterparts. These changes are attributed to phonon hardening in monolayer-thick crystals. The data reported here have bearing on applications of polaritons in metasurfaces and ultrathin optical elements