Granulocyte colony-stimulating factor attenuates chronic neuroinflammation in the brain of amyloid precursor protein transgenic mice: an Alzheimer's disease mouse model

Recent evidence suggests that inflammatory mechanisms contribute significantly to the progression of Alzheimer's disease. Granulocyte colony-stimulating factor (G-CSF) is an anti-inflammatory immunomodulator, but the mechanism of its anti-inflammatory effect is unclear. This study was designed to investigate whether G-CSF could inhibit inflammation in a mouse model of Alzheimer's disease through an α7 nicotinic acetylcholine receptor (α7 nAChR) pathway. Mice transgenic for the V171I mutant amyloid precursor protein (APP) were injected subcutaneously with G-CSF 50 μg/kg per day or phosphate-buffered saline (PBS; control group) for 7 days, and wild-type C57/BL6 mice were injected with PBS daily for 7 days. Mice were killed on days 7, 14 and 28 after treatment began. Levels of α7 nAChR protein were significantly increased and levels of interleukin-1β, tumour necrosis factor-α and nuclear factor-κB (NF-κB) protein were significantly decreased in the brain of APP transgenic mice in response to G-CSF. Levels of α7 nAChR protein correlated negatively with NF-κB levels. It is concluded that G-CSF might attenuate inflammation by down-regulating NF-κB and up-regulating α7 nAChR in the brain of APP transgenic mice, indicating a potential new therapeutic approach to Alzheimer's disease.

First Report of Anthracnose Caused by Colletotrichum gloeosporioides on Ramie in China

Ramie (Boehmeria nivea), usually called "China grass", is a perennial herbaceous plant belonging to the family Urticaceae with recognized importance in the production of fibers. It is mainly planted in China and other Asian countries including the Philippines, India, South Korea, and Thailand. From June 2007 to September 2010, typical anthracnose symptoms were observed in cultivated ramie fields in HuBei, HuNan, JiangXi, and SiChuan provinces, China, with the diseased area estimated to be more than 10,000 ha. Ramie yield was reduced by 20% on average with up to 55% yield losses in some fields. Lesions were initially small, scattered, round, and gray with brown margin on leaves. As the disease progressed, irregular spots developed and expanded until the leaves withered. Initial lesions on stems were fusiform and expanded, causing the stem to break. Finally, the fibers ruptured. Five isolates (CS-1, CS-2, CS-3, CS-4, and CS-5) were used to evaluate cultural and morphological characteristics of the pathogen. On potato dextrose agar, all isolations initially developed white colonies with orange conidial mass and the colonies turned to gray or brown after 5 days of incubation. Twenty conidia and fifteen setae were measured. Conidia were single celled, colorless, straight, oval, obtuse at both ends, and 11 to 18 × 3 to 6 μm with an average of 14.89 × 4.32 μm. Conidiophores were dense and 11 to 22 × 4 to 5 μm with an average of 15.82 × 4.43 μm. Setae were few, dark brown, one to two septa, and 62 to 71 × 4 to 5 μm with an average of 65.13 × 4.46 μm. The pathogen was identified as Colletotrichum gloeosporioides on the basis of descriptions in Bailey and Jeger (1). Genomic DNA was extracted from the five isolates and sequences of rDNA-ITS with primers ITS1 and ITS4 were obtained (GenBank Accession Nos. GQ120479-GQ120483). Comparison with sequences in GenBank showed 99 to 100% similarity with C. gloeosporioides (Accession Nos. FJ515005, FJ459930, and HM016798). Pathogenicity tests were performed with the five isolates in the laboratory by spraying conidial suspensions (1 × 10⁶ conidia/ml) onto upper and lower surfaces of 10 leaves of 10-day-old, 30-cm high plants. There were three replicate plants for each isolate. The inoculated plants were incubated with a 12-h photoperiod at 25 to 28°C and 90% relative humidity in an artificial climate chamber. Three days after inoculation, brown spots were observed on all inoculated leaves, but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by reisolation of C. gloeosporioides from diseased leaves. Though in the revision of Colletotrichum by von Arx (4) and Sutton (3), C. boehmeriae, named based on host specificity, was cancelled, C. boehmeriae was regarded as a pathogen of ramie by some Chinese researchers (2). To our knowledge, this is the first report of C. gloeosporioides causing anthracnose of ramie in China. References: (1) J. A. Bailey and M. J. Jeger. Colletotrichum: Biology, Pathology and Control. CAB International, Wallingford, UK, 1992. (2) R. M. Li and H. G. Ma. J. Plant Prot. 20:83, 1993. (3) B. C. Sutton. Page 523 in: The Coelomycetes: Fungi Imperfecti with Pycnidia, Acervuli and Stromata. Commonwealth Mycological Institute, London, 1980. (4) J. A. von Arx. Phytopathol. Z. 29:413, 1957.

First Report of Anthracnose of Digitaria sanguinalis Caused by Colletotrichum hanaui in China

Hairy crabgrass (Digitaria sanguinalis (L.) Scop.) is a troublesome weed in most agricultural crops worldwide. Considerable efforts are made to limit the invasiveness and impact of crabgrass on crop productivity, including evaluation of fungi as biocontrol agents (3). In September 2005, a severe disease was observed on crabgrass plants in Zhejiang Province. Leaves and stems of the affected plant showed small, water-soaked, brownish spots that rapidly turned into longitudinal elliptic or spindle-shaped lesions, 6.5 to 8 × 22 to 24 mm, with a brown outer edge and a gray sunken central area. Coalescence of large lesions gave rise to extensive rotting and necrosis, and the stems were broken when the lesions encircled. Acervuli with brown setae and falcate single-celled spores, typical of some Colletotrichum species (2), formed on the lesions at this late stage. One fungal isolate (Col-68) was obtained from symptomatic tissues on potato dextrose agar that led to white-to-gray appressed mycelium growth with orange conidial masses at 28°C in darkness. Setae were septate, dark brown, rounded and sometimes lobed at base, 32.0 to 116.5 × 3.2 to 6.0 μm, with apices acute. Hyphae were septate, hyaline, 1.0 to 6.5 μm, and sometimes guttulate. Conidia were falcate or fusiform, apices acute or obtuse, and 8.16 to 26.37 × 2.9 to 9.2 μm with an average of 18.15 × 5.65 μm. Hyphopodial appressoria were smooth, globose to prolate, ovoid or obovoid with obtuse or cylindrical apices, edges entire, and 4.17 to 14.25 × 3.77 to 8.94 μm with an average of 7.0 × 6.9 μm. The pathogen was initially identified as a Colletotrichum species based on morphology. Suspensions of 3-day-old spores collected from potato dextrose liquid cultures (10⁶ conidia per ml) were used to spray inoculate (15 ml per pot) three 9-cm-diameter pots of crabgrass seedlings at the three- to four-leaf growth stage. Another three pots of healthy crabgrass were simultaneously sprayed with sterilized distilled water without conidia, which served as noninoculated checks. The seedlings were kept at 25 to 28°C for 24 h under a polyethylene sheet cover in the greenhouse. Symptoms that developed in all inoculated seedlings were identical to those observed on the affected crabgrass in the field, meanwhile the seedlings inoculated with sterilized water had no significant symptoms, and the reisolated strain had the same characteristics as the original isolate. To diagnose the pathogen to the species level, three isolates were tested and an approximately 580-bp DNA amplicon of this isolate was amplified using the primers ITS1/ITS4. The sequence (GenBank Accession No. GQ456160) had 98% sequence identity with the sequences of Colletotrichum hanaui (GenBank Accession Nos. EU554101and EU554124), which is supported by phylogenetic analysis with bootstrap support. On the basis of the morphological, pathological characteristics, and phylogenetic tree, the isolated strain was identified as C. hanaui (1). To our knowledge, this is the first confirmed report of anthracnose of D. sanguinalis caused by newly described C. hanaui in China. References: (1) J. A. Crouch et al. Mycologia, 101:717, 2009. (2) B. C. Sutton. The Coelomycetes. CAB International Publishing, New York, 1980. (3) Y. Z. Zhu and S. Qiang. Chin. J. Biol. Control 20:206, 2004.

Pyrosequencing and characterization of immune response genes from the American dog tick, Dermacentor variabilis (L.)

Ticks continue to be a threat to animal and human health, and new and novel control strategies are needed for ticks and tick-borne pathogens. The characterization of the tick-pathogen interface and the tick immune response to microbial infections is fundamental toward the formulation of new control strategies for ticks and the pathogens they transmit. Our overall hypothesis for this research is that the tick immune system manages the maintenance of pathogens. Therefore, discovery of tick immune response genes may provide targets for novel control strategies directed toward reducing vector competency and pathogen transmission. In these studies, 454 pyrosequencing, a high-throughput genomic sequencing method was used to discover tick genes expressed in response to bacterial and fungal infections. Expressed sequence tags (ESTs) were analysed from Dermacentor variabilis ticks that had been injected with bacteria (Escherichia coli, Bacillus subtilis, Micrococcus luteus) or fungi (Saccharomyces cerevisiae and Candida albicans) and ticks that were naturally infected with the intracellular bacterium, Anaplasma marginale. By this approach, ESTs were assembled into 5995 contigs. Contigs fell into the five main functional categories of metabolism, genetic information processing, environmental information processing, cellular processes and human diseases. We identified more than 30 genes that are likely to encode for proteins involved in tick immune function. We further analysed by reverse transcriptase PCR (RT-PCR) the expression of 22 of these genes in each of our bacterial or fungal treatment groups and found that seven were up-regulated. Up-regulation of these seven genes was confirmed for bacterial, but not fungal treatment by quantitative PCR (qPCR). One of these products was novel, encoding a new tick defensin. Our results clearly demonstrate the complexities of the tick immune system and mark new directions for further study and characterization of proteins that modulate microbial infections in the American dog tick.

Changes in ensemble activity of hippocampus CA1 neurons induced by chronic morphine administration in freely behaving mice

The hippocampus plays an important role in the formation of new memories and spatial navigation. Recently, growing evidence supports the view that it is also involved in addiction to opiates and other drugs. Theoretical and experimental studies suggest that hippocampal neural-network oscillations at specific frequencies and unit firing patterns reflect information of learning and memory encoding. Here, using multichannel recordings from the hippocampal CA1 area in behaving mice, we investigated the phase correlations between the theta (4-10 Hz) and gamma (40-100 Hz) oscillations, and the timing of spikes modulated by these oscillations. Local field potentials and single unit recordings in the CA1 area of mice receiving chronic morphine treatment revealed that the power of the theta rhythm was strongly increased; at the same time, the theta frequency during different behavioral states shifted markedly, and the characteristic coupling of theta and gamma oscillations was altered. Surprisingly, though the gamma oscillation frequency changed, the power of gamma lacking theta did not. Moreover, the timing of pyramidal cell spikes relative to the theta rhythm and the timing of interneuron spikes relative to the gamma rhythm changed during chronic morphine administration. Furthermore, these responses were impaired by a selective D1/D5 receptor antagonist intra-hippocampus injection. These results indicate that chronic morphine administration induced the changes of ensemble activity in the CA1 area, and these changes were dependent on local dopamine receptor activation.

Neural stem cells reduce hippocampal tau and reelin accumulation in aged Ts65Dn Down syndrome mice

Tau accumulation, in the form of neurofibrillary tangles (NFT), is an early neuropathological characteristic of Alzheimer's disease (AD) and early onset AD frequently seen in Down syndrome (DS). We investigated the presence of tau accumulation in the brains of aging DS mice using the Ts65Dn mouse model. All aged mice appeared to have substantial clusters of extracellular granules that were positive for tau and reelin, but not for amyloid-β or APP. These clusters were found primarily in CA1 of the hippocampus. In addition, the aged trisomic DS mice had a significantly greater accumulation of extracellular tau/reelin granular deposits compared to disomic littermates. These granules were similar to those described by others who also found extracellular proteinous granules in the brains of non-DS mice engineered to model aging and/or AD. When neural stem cells (NSC) were implanted unilaterally into the hippocampus of the Ts65Dn mice, the tau/reelin-positive granules were significantly reduced in both trisomic and disomic mice. Our findings indicate that changes in tau/reelin-positive granules could be used as an index for neuropathological assessment in aging DS and AD. Furthermore, changes in granule density could be used to test the efficacy of novel treatments, such as NSC implantation. Lastly, it is speculated that the unique abilities of NSC to migrate and express growth factors might be a contributing factor to reducing tau/reelin accumulation in aging DS and AD.

Growth inhibitory and apoptosis-inducing effects of xanthohumol, a prenylated chalone present in hops, in human prostate cancer cells

Promotion of apoptosis in cancer cells could potentially lead to the regression and improved prognosis of hormone-refractory prostate cancer. Xanthohumol (XN), a prenylated chalcone-derived from hops, has shown strong antitumorigenic activity towards diverse types of cancer cells. In the present study, the growth-inhibitory and apoptosis-inducing activity of XN was tested in hormone-sensitive and hormone-refractory human prostate cancer cells lines. Cell growth/viability assay (MTS) demonstrated that prostate cancer cells are highly sensitive to XN at a concentration range of 20-40 μM. The primary mode of tumor cell destruction was apoptosis as demonstrated by the binding of annexin V-FITC, cleavage of PARP-1, activation of procaspases -3, -8, and -9, mitochondrial depolarization and release of cytochrome c from mitochondria. Induction of apoptosis by XN was associated with the inhibition of prosurvival Akt, NF-κB and mTOR signaling proteins and NF-κB-regulated anti-apoptotic Bcl-2 and survivin. These studies provide a rationale for clinical evaluation of XN for the treatment of hormone-refractory metastatic prostate cancer.

The dendritic cell mannose receptor mediates allergen internalization and maturation involving notch 1 signalling

Dendritic cells (DCs) have been shown recently to play a key role in inducing and mediating T helper type 2 (Th2) responses associated with atopic disease. These responses are mediated in part by ligation to different Toll-like receptors (TLRs) and C-type lectins, e.g. the mannose receptor (MR), depending upon the DC subset involved and the respective microenvironments. Because ovalbumin (OVA) (which is structurally related to various allergens) can engage the MR, we can use OVA stimulation as a model for understanding the roles of both TLRs and the MR in allergic inflammatory responses. We examined TLR- and MR-mediated responses from mouse bone marrow-derived DCs in the context of antigen recognition and presentation in addition to examining the relationship between notch 1, TLRs and MR signalling pathways. This work demonstrated that OVA-mediated signalling up-regulated both TLR-2 and MR and that MR RNA interference (RNAi) but not TLR2 RNAi inhibited DC internalization of fluorescein isothiocyanate-OVA. Furthermore, MR RNAi inhibited OVA- and house dust mite allergen extract-induced DC maturation and MR RNAi and TLR2 RNAi influenced DC interleukin-12 production independently. Finally, we demonstrated that blocking notch 1 signalling inhibited both notch 1 and TLR-2 expression but not MR expression levels. However, MR RNAi inhibited the expression of MR, TLR-2 and notch 1. These results indicate that MR is the primary receptor mediating the internalization of environmental allergen glycoproteins. In addition, TLR-2 and notch 1 play important roles in DC maturation and antigen presentation and signals originating from the MR and TLR-2 receptors converge with the notch 1 signalling pathway.

Genome-wide analysis of cyclins in maize (Zea mays)

Cyclins are primary regulators of the activity of cyclin-dependent kinases and play crucial roles in cell cycle progression in eukaryotes. Although extensive studies have revealed the roles of some cyclins and underlying mechanisms in plants, relatively few cyclins have been functionally analyzed in maize. We identified 59 cyclins in the maize genome, distributed on 10 chromosomes; these were grouped into six types by phylogenetic analysis. The cyclin genes in the maize genome went through numerous tandem gene duplications on five chromosomes. However, no segmental duplications, which occur in rice, were found on maize chromosomes. This information allows us to assess the position of plant cyclin genes in terms of evolution and classification, which will be useful for functional studies of maize cyclins.

Upregulation of caspase-3 expression in esophageal cancer correlates with favorable prognosis: an immunohistochemical study from a high incidence area in northern China

Caspase-3 plays an important role as the key effector during apoptosis, but there are very few studies of caspase-3 in esophageal squamous cell carcinoma (ESCC). The purpose of this study was to investigate the expression and prognostic significance of caspase-3 in ESCC from Linzhou City, a high incidence area in northern China. All 64 patients underwent esophagectomy for ESCC between January 2002 and December were enrolled in this study. Caspase-3 expression was assessed by immunohistochemistry (IHC) in primary ESCC and paired normal esophageal epithelium. The positive rate of caspase-3 expression was higher in ESCC than in normal esophageal epithelium (79.7% vs. 50.0%, Chi-square = 12.372, P= 0.001). Caspase-3 expression was correlated with tumor cell differentiation (Phi = 0.717, P < 0.001), tumor infiltration depth (Phi =-0.334, P= 0.008), and pathologic TNM (pTNM) staging (rs =-0.268, P= 0.032). Patients in caspase-3 positive group had a significantly better 5-year overall survival than those in the negative group (77.4% vs. 35.9%, chi(2)= 7.344, P= 0.007). Our results showed that caspase-3 expression was upregulated in ESCC compared with normal esophageal epithelium in population of Chinese high incidence area, and patients with caspase-3 positive expression had better prognosis. Therefore, caspase-3 immunostaining could be a simple and useful tool for predicting survival in ESCC patients.

Impact of clinical condition at restarting dialysis on outcome after kidney allograft loss: a single-center experience

BACKGROUND

The purpose of this paper was to determine the impact of the clinical condition of the patient at the restart of dialysis on long-term survival after renal graft loss.

METHODS

We performed an analysis of 110 patients with renal allograft failure compared with 115 hemodialysis patients without kidney transplantation.

RESULTS

There was a relatively high glomerular filtration rate, low serum albumin, and greater prevalence of infection among graft loss patients compared with the never-transplanted patients. Patient survival after allograft loss was significantly lower than that of never-transplanted patients (P = .024) with 63.4% patients succumbing in the first 3 months. Serum hepatitis B virus (HBV) positivity, cardiovascular disease (CVD) and malnutrition were independent risk factors for graft loss patient upon COX regression analysis.

CONCLUSIONS

Serum HBV positive, complicated with CVD and malnutrition were independent risk factors for the graft loss among patients who restarted hemodialysis. More attention should be paid to treat complications of transplant recipients in K/DOQI 4 and 5 stages.

Rumen fluid inhibits proliferation and stimulates expression of cyclin-dependent kinase inhibitors 1A and 2A in bovine rumen epithelial cells

It has been known for decades that microbial fermentation within the rumen is critical to postnatal rumen epithelial growth and maturation in ruminants, but the underlying mechanism is largely unknown. In this study, we determined the effect of rumen fluid, which should contain all products from rumen fermentation, on growth of rumen epithelial cells in vitro. Addition of 10% rumen fluid from cows to the culture medium inhibited (P < 0.05), whereas addition of 6.5 mM acetate, 2.5 mM propionate, or 1 mM butyrate had no effect (P > 0.1) on, the proliferation of rumen epithelial cells isolated from newborn calves. Flow cytometric assays showed that 10% rumen fluid inhibited (P < 0.05) the transition of rumen epithelial cells from the G1 phase to the S phase during the cell cycle. Real-time RT-PCR analyses of mRNA for key cell cycle regulators indicated that 10% rumen fluid did not change (P > 0.1) the expression of cyclin D1, D2, D3, E1, or E2 mRNA or that of cyclin-dependent kinase inhibitor 1B or 2B mRNA, but increased (P < 0.05) the expression of cyclin-dependent kinase inhibitors 1A and 2A mRNA in rumen epithelial cells. These mRNA data support the possibility that rumen fluid inhibits proliferation of rumen epithelial cells in vitro by increasing the expression of cyclin-dependent kinase inhibitors 1A and 2A. The result that rumen fluid inhibits proliferation of bovine rumen epithelial cells in culture indicates that rumen fermentation does not stimulate the postnatal rumen epithelial growth in cattle by directly stimulating proliferation of rumen epithelial cells.

Randomized clinical trial of intravenous soybean oil alone versus soybean oil plus fish oil emulsion after gastrointestinal cancer surgery

BACKGROUND

Specific immunonutrients may reduce the incidence of postoperative complications and shorten recovery time. This randomized trial evaluated the clinical efficacy of a fish oil emulsion on outcome and immune function after gastrointestinal cancer surgery.

METHODS

A total of 206 patients with gastrointestinal or colonic cancer were randomized to receive isocaloric and isonitrogenous intravenous infusions of either soybean oil alone (1.2 g per kg bodyweight per day; control group, 103 analysed) or soybean plus fish oil emulsion (1.0 and 0.2 g per kg per day respectively; treatment group, 100 analysed) over 20-24 h daily for 7 days after surgery.

RESULTS

Baseline data were comparable in the two groups. There were fewer infectious complications (four versus 12 on day 8; P = 0.066), systemic inflammatory response syndrome (SIRS) was significantly less common (four versus 13; P = 0.039) and hospital stay was significantly shorter (mean(s.d.) 15(5) versus 17(8) days; P = 0.041) in the treatment group. Total postoperative medical costs were comparable in the two groups (mean(s.d.) US $ 1269(254) and 1302(324) in treatment and control groups respectively; P = 0.424). The median (interquartile range) difference in CD4/CD8 between days 1 and 8 after surgery was + 0.30 (0.06 to 0.79) in patients receiving fish oil and + 0.20 (-0.19 to 0.55) in controls (P = 0.021). No severe adverse events occurred in either group.

CONCLUSION

Fish oil emulsion-supplemented parenteral nutrition significantly reduced SIRS and length of hospital stay. These clinical benefits may be related to normalization of cellular immune functions and modulation of the inflammatory response.

Orbital-dependent Representation of Correlation Energy Functional

Exchange-correlation energy functionals depending on the Kohn-Sham orbitals and eigenvalues resolve some of the well-known deficiencies of the local density and generalized gradient approximations. Such functionals can be derived in first-principles fashion by use of standard many-body techniques, if the Kohn-Sham Hamiltonian is utilized as non-interacting reference Hamiltonian. In this way one can establish an exact relation for the exchange-correlation functional, which opens several routes for the derivation of approximate functionals. Straightforward expansion in powers of the electron-electron coupling constant gives, to first order, the exact exchange of density functional theory and, to second order, a correlation functional which has the same structure as the second order Møller-Plesset term. This simplest first-principles correlation functional reproduces both the shell structure in the exact correlation potential and dispersion forces. On the other hand, it overestimates all correlation effects and is variationally instable for systems with a very small HOMO-LUMO gap. Both deficiences can be resolved by partial resummation of the Kohn-Sham perturbation expansion. In this contribution two such resummations are discussed, a minimum form designed to address the variational instability at no computational cost (based on the Epstein-Nesbet diagrams) and a more systematic variant (based on the ring diagrams).