Novel technique for the direct flow cytofluorometric analysis of human basophils in unseparated blood and bone marrow, and the characterization of phenotype and peroxidase of human basophils

BACKGROUND: No technique has been reported to analyze directly the antigen expression on basophil leukocytes when using a flow cytometer; therefore, the exact phenotype of human basophils and the character of the peroxidase in basophils are not well understood. METHODS: Human blood basophils were purified by using an antibody against high-affinity Fc epsilon receptor (hFcepsilonR) and a MACS magnetic cell sorting system and then cytochemically stained. The phenotype and peroxidase of the human basophils were flow cytofluorometrically analyzed directly in unseparated blood and bone marrow samples as hFcepsilonR+/MBP+ (major basic protein)/Hist+ (histamine) light-density cells distributed in the high sidescatter area of lymphocytes on light scattergrams. RESULTS: The peroxidase granules of human basophils were stained by an anti-eosinophil peroxidase (EPO) antibody. The human blood basophils had common granulocyte markers plus CD25, i.e., they were CD11a/ CD11b/CD11c/CD25/CD38/CD13/CD33/hFcepsi lonR/MBP/Hist/ EPO positive, CD71 dim positive, CD14/CD15 partially positive, and CD2/CD3/CD7/CD122/CD16/CD56/CD57/ CD10/CD19/CD20/CD22/HLA-DR/MPO (myeloperoxidase)/CD23 negative. Further examination was done to analyze the expression of colony-stimulating factor receptors on three lineages of granulocytes, i.e., basophils, eosinophils, and neutrophils. The neutrophils were CD114 (G-CSFR)/CD116 (GM-CSFR)/CD124 [interleukin (IL)-4R]/CD126 (IL-6R) positive and CD123 (IL-3R)/CD125 (IL-5R) negative. In contrast, the eosinophils and basophils were CD116/CD123/CD125/CD126 positive and CD114/CD124 negative. CONCLUSIONS: This novel technique for directly characterizing human basophil leukocytes with flow cytometry may be a convenient way to screen the expression of surface antigens and the cytoplasmic expression of CD antigens and other proteins in human blood basophils and to analyze alterations of the character of basophils by cytokines and other biological substances in vivo and in vitro.     

Germ-free status and altered caecal subdominant microbiota are associated with a high susceptibility to cow's milk allergy in mice

Studies suggesting that the development of atopy is linked to gut microbiota composition are inconclusive on whether dysbiosis precedes or arises from allergic symptoms. Using a mouse model of cow's milk allergy, we aimed at investigating the link between the intestinal microbiota, allergic sensitization, and the severity of symptoms. Germ-free and conventional mice were orally sensitized with whey proteins and cholera toxin, and then orally challenged with β-lactoglobulin (BLG). Allergic responses were monitored with clinical symptoms, plasma markers of sensitization, and the T-helper Th1/Th2/regulatory-T-cell balance. Microbiota compositions were analysed using denaturing gradient gel electrophoresis and culture methods. Germ-free mice were found to be more responsive than conventional mice to sensitization, displaying a greater reduction of rectal temperature upon challenge, higher levels of blood mouse mast cell protease-1 (mMCP-1) and BLG-specific immunoglobulin G1 (IgG1), and a systemic Th2-skewed response. This may be explained by a high susceptibility to release mMCP-1 even in the presence of low levels of IgE. Sensitization did not alter the microbiota composition. However, the absence of or low Staphylococcus colonization in the caecum was associated with high allergic manifestations. This work demonstrates that intestinal colonization protects against oral sensitization and allergic response. This is the first study to show a relationship between alterations within the subdominant microbiota and severity of food allergy.     

Glycosaminoglycan profile of peritoneal and bone marrow-derived macrophages. Changes associated with macrophage activation.

1. We have analysed the glycosaminoglycan patterns of peritoneal and bone marrow-derived macrophages obtained from four different mouse strains which are resistant (A/J) or susceptible (BALB/c, DBA and C-57) to murine hepatitis virus type 3 (MHV3) infection. The glycosaminoglycans were biosynthetically labelled by exposing the macrophages to 35S-sulphate. The medium and cell fractions were collected and the 35S-glycosaminoglycans formed were identified by a combination of agarose gel electrophoresis and enzymatic degradation with bacterial mucopolysaccharidases. 2. Both peritoneal and bone marrow-derived macrophages synthesize and secrete a mixture of dermatan sulphate, heparan sulphate and chondroitin sulphate. Dermatan sulphate is the main glycosaminoglycan and most of the synthesized glycosaminoglycans are released to the culture medium. 3. The glycosaminoglycan patterns vary depending on the macrophage source. Bone marrow-derived cells synthesize glycosaminoglycans at lower rates, release a lower glycosaminoglycan percentage to the culture medium and express higher amounts of heparan sulphate in comparison with their peritoneal counterparts. Furthermore, LPS-induced activation leads to an increased glycosaminoglycan expression in bone marrow-derived macrophages and to a decrease in 35S-glycosaminoglycans of peritoneal macrophages from BALB/c, A/J and C-57 mice. 4. We have not established any correlation between macrophage glycosaminoglycans and resistance to MHV3 infection, since the glycosaminoglycan patterns of resistant (A/J) and susceptible (BALB/c, DBA and C-57) mouse macrophages are similar. Furthermore, the in vitro infection of both control and LPS-activated peritoneal macrophages with MHV3 did not cause any changes in the expression of glycosaminoglycans.     

The pro-metastatic role of bone marrow-derived cells: a focus on MSCs and regulatory T cells

Several bone marrow-derived cells have been shown to promote tumour growth and progression. These cells can home to the primary tumour and become active components of the tumour microenvironment. Recent studies have also identified bone marrow-derived cells—such as mesenchymal stem cells and regulatory T cells—as contributors to cancer metastasis. The innate versatility of these cells provides diverse functional aid to promote malignancy, ranging from structural support to signal-mediated suppression of the host immune response. Here, we review the role of mesenchymal stem cells and regulatory T cells in cancer metastasis. A better understanding of the bipolar nature of these bone marrow-derived cells in physiological and malignant contexts could pave the way for new therapeutics against metastatic disease.     

Dexamethasone, BMP-2, and 1,25-dihydroxyvitamin D enhance a more differentiated osteoblast phenotype: validation of an in vitro model for human bone marrow-derived primary osteoblasts

In vitro models of bone cells are important for the study of bone biology, including the regulation of bone formation and resorption. In this study, we have validated an in vitro model of human osteoblastic cells obtained from bone marrow biopsies from healthy, young volunteers, aged 20-31 years. Osteoblast phenotypes were induced by either dexamethasone (Dex) or bone morphogenetic protein-2 (BMP-2). Bone marrow was obtained from biopsies at the posterior iliac spine. Cells were isolated by gradient centrifugation and grown to confluence. Cells were treated with 1 nM 1,25-dihydroxyvitamin D (vitamin D), 100 nM Dex, and/or 100 ng/ml BMP-2. The osteoblast phenotype was assessed as alkaline phosphatase (AP) activity/staining, production of osteocalcin and procollagen type 1 (P1NP), parathyroid hormone (PTH)-induced cyclic adenosine mono-phosphate (cAMP) production, and in vitro mineralization. AP activity was increased by Dex, but not by BMP-2 treatment. P1NP production was decreased after Dex treatment, while BMP-2 had no effect on P1NP levels. Osteocalcin production was low in cultures not stimulated with vitamin D. Dex or BMP-2 treatment alone did not affect the basic osteocalcin levels, but in combination with vitamin D, BMP-2 increased the osteocalcin production, while Dex treatment completely suppressed osteocalcin production. Further, PTH-induced cAMP production was greatly enhanced by Dex treatment, whereas BMP-2 did not affect cAMP production. Finally, in vitro mineralization was greatly enhanced in cultures enriched with either BMP-2 or Dex. Cell proliferation was only increased significantly by Dex treatment. In conclusion, the model described produces cells with an osteoblastic phenotype, and both Dex and BMP-2 can be used as osteoblast inducers. However, the two treatments produce osteoblastic cells with different phenotypic characteristics, and a selective activation of some of the most important genes and functions of the mature osteoblast can thus be performed in vitro.     

Cryptococcus neoformans suppresses the activation of bone marrow-derived dendritic cells stimulated with its own DNA, but not with DNA from other fungi

DNA from Cryptococcus neoformans activates bone marrow-derived dendritic cells (BM-DCs) in a TLR9-dependent manner. In this study, we examined the effect of the culture supernatants of C. neoformans on the activation of BM-DCs caused by its own DNA. C. neoformans supernatants suppressed IL-12p40, IL-6 production and CD40 expression by BM-DCs stimulated with its own DNA, but not with CpG-ODN and DNA from Candida albicans, Saccharomyces cerevisiae or Escherichia coli. In a confocal microscopic analysis, C. neoformans DNA was colocalized with LAMP-1, a late endosomal marker, and TLR9. The culture supernatants did not show any apparent suppression of these responses. In a luciferase reporter assay, C. neoformans supernatants inhibited NFκB activation caused by its own DNA. These inhibitory activities were attenuated by treatment with heat or trypsin. These results indicate that C. neoformans secrete certain proteinous molecules that suppress the activation of BM-DCs caused by its own DNA.     

Obesity and altered glucose metabolism impact HDL composition in CETP transgenic mice: a role for ovarian hormones

Mechanisms underlying changes in HDL composition caused by obesity are poorly defined, partly because mice lack expression of cholesteryl ester transfer protein (CETP), which shuttles triglyceride and cholesteryl ester between lipoproteins. Because menopause is associated with weight gain, altered glucose metabolism, and changes in HDL, we tested the effect of feeding a high-fat diet (HFD) and ovariectomy (OVX) on glucose metabolism and HDL composition in CETP transgenic mice. After OVX, female CETP-expressing mice had accelerated weight gain with HFD-feeding and impaired glucose tolerance by hyperglycemic clamp techniques, compared with OVX mice fed a low-fat diet (LFD). Sham-operated mice (SHAM) did not show HFD-induced weight gain and had less glucose intolerance than OVX mice. Using shotgun HDL proteomics, HFD-feeding in OVX mice had a large effect on HDL composition, including increased levels of apoA2, apoA4, apoC2, and apoC3, proteins involved in TG metabolism. These changes were associated with decreased hepatic expression of SR-B1, ABCA1, and LDL receptor, proteins involved in modulating the lipid content of HDL. In SHAM mice, there were minimal changes in HDL composition with HFD feeding. These studies suggest that the absence of ovarian hormones negatively influences the response to high-fat feeding in terms of glucose tolerance and HDL composition. CETP-expressing mice may represent a useful model to define how metabolic changes affect HDL composition and function.     

Immunophenotype and differentiation capacity of bone marrow-derived mesenchymal stem cells from CBA/Ca,ICR and Balb/c mice

AIM:To assess the capacity to isolate and expand mesenchymal stem cells(MSC)from bone marrow of CBA/Ca,ICR and Balb/c mice. METHODS:Bone marrow of tibia and femur were flushed,cultured and maintained in supplemented Dulbecco’s modified Eagle’s medium.MSC immunophenotype of cultures were tracked along increasing passages for positivity to CD106,Sca-1 and CD44 and negativity to CD45,CD11b and MHC classⅡ.Differentiation capacity of MSC towards osteogenic and adipo-genic lineages were also assessed. RESULTS:MSC were successfully cultured from bone marrow of all 3 strains,albeit differences in the temporal expression of certain surface antigens.Their differentiation into osteocytes and adipocytes were also observed. MSC from all 3 mouse strains demonstrated a shift from a haematopoietic phenotype(CD106-CD45+CD11b+Sca-1low)to typical MSC phenotype(CD106+CD45-CD11b-Sca-1high)with increasing passages. CONCLUSION:Information garnered assists us in the decision of selecting a mouse strain to generate MSC from for downstream experimentation.     

IFN-gamma production by intrinsic renal cells and bone marrow-derived cells is required for full expression of crescentic glomerulonephritis in mice

The contribution of IFN-gamma from bone marrow (BM) and non-BM-derived cells to glomerular and cutaneous delayed-type hypersensitivity (DTH) was studied in mice. Chimeric IFN-gamma mice (IFN-gamma(+/+) BM chimera), in which IFN-gamma production was restricted to BM-derived cells, were created by transplanting normal C57BL/6 (wild-type (WT)) BM into irradiated IFN-gamma-deficient mice. BM IFN-gamma-deficient chimeric mice (IFN-gamma(-/-) BM chimera) were created by transplanting WT mice with IFN-gamma-deficient BM. WT and sham chimeric mice (WT mice transplanted with WT BM) developed crescentic glomerulonephritis (GN) with features of DTH (including glomerular T cell and macrophage infiltration) in response to an Ag planted in their glomeruli and skin DTH following subdermal Ag challenge. IFN-gamma-deficient mice showed significant protection from crescentic GN and reduced cutaneous DTH. IFN-gamma(+/+) BM chimeric and IFN-gamma(-/-) BM chimeric mice showed similar attenuation of crescentic GN as IFN-gamma-deficient mice, whereas cutaneous DTH was reduced only in IFN-gamma(-/-) BM chimeras. In crescentic GN, IFN-gamma was expressed by tubular cells and occasional glomerular cells and was colocalized with infiltrating CD8(+) T cells, but not with CD4(+) T cells or macrophages. Renal MHC class II expression was reduced in IFN-gamma(+/+) BM chimeric mice and was more severely reduced in IFN-gamma-deficient mice and IFN-gamma(-/-) BM chimeric mice. These studies show that IFN-gamma expression by both BM-derived cells and intrinsic renal cells is required for the development of crescentic GN, but IFN-gamma production by resident cells is not essential for the development of cutaneous DTH.     

Stress early in life leads to cognitive impairments,reduced numbers of CA3 neurons and altered maternal behavior in adult female mice

The hippocampus is a crucial part of the limbic system involved both in cognitive processing and in the regulation of responses to stress. Adverse experiences early in life can disrupt hippocampal development and lead to impairment of the hypothalamic‐pituitary‐adrenal axis response to subsequent stressors. In our study, two types of early‐life stress were used: prolonged separation of pups from their mothers (for 3 hours/day, maternal separation, MS) and brief separation (for 15 minutes/day, handling, HD). In the first part of our study, we found that adult female mice (F0) who had experienced MS showed reduced locomotor activity and impairment of long‐term spatial and recognition memory. Analysis of various hippocampal regions showed that MS reduced the number of mature neurons in CA3 of females, which is perhaps a crucial hippocampal region for learning and memory; however, neurogenesis remained unchanged. In the second part, we measured maternal care in female mice with a history of early‐life stress (F0) as well as the behavior of their adult offspring (F1). Our results indicated that MS reduced the level of maternal care in adult females (F0) toward their own progeny and caused sex‐specific changes in the social behavior of adult offspring (F1). In contrast to MS, HD had no influence on female behavior or hippocampal plasticity. Overall, our results suggest that prolonged MS early in life affects the adult behavior of F0 female mice and hippocampal neuronal plasticity, whereas the mothers' previous experience has effects on the behavior of their F1 offspring through disturbances of mother‐infant interactions.     

Diminished reproduction, failure to thrive, and altered immunologic function in a colony of T-cell receptor transgenic mice: possible role of Citrobacter rodentium

Citrobacter rodentium from an undetermined source was detected in a breeding colony of T-cell receptor transgenic mice housed in a conventional mouse facility in which murine hepatitis virus had been endemic and Helicobacter spp. had been detected. Citrobacter rodentium, isolated from blood, spleen, and colon, correlated with a significant increase in mortality and morbidity in this breeding colony. Transgenic mice of all ages were affected by chronic debilitation, loss in reproductive efficiency, rectal prolapse, and acute death, resulting in the near loss of these noncommercially available strains. Several alterations in immunologic parameters were observed, including outgrowth of an unusual population of cells in the spleen and blood, reduction in ascites production, loss of the capacity of peritoneal exudate cells to serve as feeders for the cloning of long-term T-cell lines, and inhibition of antigen-specific cytotoxic T-cell activity. These altered immune functions also were apparent in commercially-derived nontransgenic mice cohoused with the infected colony and in overtly healthy transgenic and nontransgenic littermates. Citrobacter rodentium and murine hepatitis virus were eliminated ultimately on rederivation of the affected strains by embryo transfer. However, the rapid decrease in the health of the colony necessitated more immediate action. To reduce mortality and allow breeding to continue during rederivation of the transgenic lines, animals were treated with enrofloxacin and moved to a barrier facility. Antibiotic therapy significantly reduced morbidity and mortality, markedly increased litter size and frequency, and resulted in the normalization of many of the immunologic assays. The involvement of C. rodentium in altering viability of the colony and perturbing immunologic assays is suggested by correlation of the onset of the syndrome with the appearance of Citrobacter sp. and its resolution with the elimination of Citrobacter sp. from the colony. Whether infection with Citrobacter alone is causative or whether superinfection of murine hepatitis virus- and Helicobacter-infected mice is required remains to be determined.     

Genetic control of responses to bacterial lipopolysaccharides in mice. II. A gene that influences a membrane component involved in the activation of bone marrow-derived lymphocytes by lipipolysaccharides.

C3H/HeJ mice contain a defect in a single autosomal locus which is not linked to the H-2 histocompatibility or the heavy chain allotype loci that restrict immune, mitogenic, and polyclonal responses to bacterial lipopolysaccharides (LPS). Adult thymectomized C3H/HeJ mice that have been irradiated and reconstituted with C3HeB/FeJ bone marrow cells respond well to LPS. Cell-mixing experiments using C3H/HEJ-C3HeB/FeJ spleen cultures show that the failure of C3H/HeJ spleen cells to support responses to LPS is not due to nonspecific or LPS-induced suppressive events, or the lack of accessory cell types. C3H/HeJ and C3HeB/FeJ spleen cells bind LPS and respond to other B cell mitogens equally well. We suggest that the B lymphocytes of C3H/HeJ mice have a defect in a membrane component that is activated via interaction with LPS, and initiates the intracellular events that lead to cell proliferation.     

肠道菌群在肿瘤发生发展及免疫治疗中作用的研究进展北大核心CSCD

肠道菌群是一个与人体共生的复杂微生物区系,近年来被越来越多的研究者所关注。研究发现,肠道菌群不仅在维持人体正常生理功能中起到重要作用,在肿瘤发生、发展、诊断及治疗中也有不可忽视的作用。本文在对肠道菌群与肿瘤关系进行概述的基础上,重点介绍了肠道菌群促进肿瘤发生、发展的主要机制,以及肠道菌群对抗肿瘤免疫治疗尤其是免疫检查点抑制疗法的影响。此外,文中还总结了目前可行的调节肠道菌群以提高肿瘤治疗疗效的方法,并提出了其中可能存在的困难和挑战。     

Atrazine resistance entails a limited xanthophyll cycle activity,a lower PSII efficiency and an altered pattern of excess excitation dissipation

Atrazine-resistant (AR) weeds have a modified D1 protein structure, with a Ser₂₆₄→Gly mutation on the D1 protein, near the plastoquinone binding niche. The photosynthetic performance, the light response of the xanthophyll cycle and chlorophyll fluorescence quenching-related parameters were compared in attached leaves of susceptible (S) and AR biotypes of the C₃ dicot Chenopodium album L., Epilobium adenocaulon Hausskn., Erigeron canadensis L., Senecio vulgaris L. and Solanum nigrum L. and the C₄ dicot Amaranthus retroflexus L. grown under natural high-light conditions. No significant difference in CO₂ assimilation rate per leaf area unit was found between the S and AR biotypes of the investigated C₃ plants, whereas the AR biotype of A. retroflexus exhibited a relatively poor photosynthetic performance. The D1 protein mutant plants expressed a reduced activity of light-stimulated zeaxanthin formation. Neither the lower violaxanthin de-epoxidase activity nor the depletion of ascorbate seems to be the cause of the lower in vivo zeaxanthin formation in the AR plants. All the D1 mutant weeds had limited light-induced non-photochemical (NPQ) and photochemical (q_P) quenching capacities, and displayed a higher photosensitivity, as characterized by the ratio (1-q_P)/NPQ and a higher susceptibility to photoinhibition. Analysis of the chlorophyll fluorescence parameters showed that a lower proportion of excitation energy was allocated to PSII photochemistry, while a higher excess of excitation remained in the AR weeds relative to the S plants.     

Expression of a binding structure for sialic acid-containing glycoconjugates on rat bone marrow-derived macrophages and its modulation by IFN, TNF-alpha, and dexamethasone

Rat macrophages express a binding structure for sialic acid-containing glycoconjugates (sialic acid-binding receptor, SAR) which can be detected by a rosette assay utilizing SRBC coated with bovine brain gangliosides (E-G). Freshly isolated rat bone marrow cells (BMC) contain about 5% SAR-positive cells. Rat BMC cultured for 1 wk with tissue culture media containing CSF-1 differentiate into a virtually pure population of bone marrow-derived macrophages (BMDM phi). All BMDM phi bound E-G coated with an optimal concentration of gangliosides (100 micrograms/ml). When BMC were cultured for 1 wk with murine recombinant granulocyte-macrophage CSF, irrespective of the dose of GM-CSF, approximately 90% of the cells were identified as rat macrophages, and practically all expressed SAR. Only about 50% of BMDM phi bound SRBC coated with a suboptimal concentration of gangliosides (20 micrograms/ml). However, this percentage increased markedly after 8 to 72 h incubation with 1 to 10,000 U/ml purified murine IFN-alpha or IFN-beta, whereas murine or rat rIFN-gamma at doses above 10 U/ml led to a decrease of E-G binding. Human and murine rTNF-alpha enhanced rosette formation in a dose-dependent manner. These effects could be blocked by the respective anti-cytokine antibodies. Treatment of BMDM phi with dexamethasone also augmented E-G rosetting. The enhancement of E-G binding was abolished by pretreatment of BMDM phi with cycloheximide and actinomycin D but not with mitomycin C, suggesting that de novo synthesis of protein and RNA, but not DNA, is required. Our results demonstrate that all rat BMDM phi constitutively bear SAR, and that murine IFN-alpha, IFN-beta, and TNF-alpha, as well as dexamethasone, may augment SAR expression.     

The role of estrogen receptor-beta, in the early age-related bone gain and later age-related bone loss in female mice

The molecular and cellular mechanism of estrogen action in skeletal tissue remains unclear. The purpose of this study was to understand the role of estrogen receptor-beta, (ERbeta) on cortical and cancellous bone during growth and aging by comparing the bone phenotype of 6- and 13-month-old female mice with or without ERbeta. Groups of 11-14 wild-type (WT) controls and ERbeta knockout (BERKO) female mice were necropsied at 6 and 13 months of age. At both ages, BERKO mice did not differ significantly from WT controls in uterine weight and uterine epithelial thickness, indicating that ERbeta does not regulate the growth of uterine tissue. Femoral length increased significantly by 5.5% at 6 months of age in BERKO mice compared with WT controls. At 6 months of age, peripheral quantitative computerized tomography (pQCT) analysis of the distal femoral metaphysis (DFM) and femoral shafts showed that BERKO mice had significantly higher cortical bone content and periosteal circumference as compared with WT controls at both sites. In contrast to the findings in cortical bone, at 6 months of age, there was no difference between BERKO and WT mice in trabecular density, trabecular bone volume (TBV), or formation and resorption indices at the DFM. In 13-month-old WT mice, TBV (-41%), trabecular density (-27%) and cortical thickness decreased significantly. while marrow cavity and endocortical circumference increased significantly compared with 6-month-old WT mice. These age-related decreases in cancellous and endocortical bone did not occur in BERKO mice. At 13 months of age, BERKO mice had significantly higher total, trabecular and cortical bone, while having significantly lower bone resorption, bone formation and bone turnover in DFM compared with WT mice. These results indicate that deleting ERbeta protected against age-related bone loss in both the cancellous and endocortical compartments by decreasing bone resorption and bone turnover in aged female mice. These data demonstrate that in female mice, ERbeta plays a role in inhibiting periosteal bone formation, longitudinal and radial bone growth during the growth period, while it plays a role in stimulating bone resorption, bone turnover and bone loss on cancellous and endocortical bone surfaces during the aging process.     

Trans-eQTLs reveal that independent genetic variants associated with a complex phenotype converge on intermediate genes, with a major role for the HLA

For many complex traits, genetic variants have been found associated. However, it is still mostly unclear through which downstream mechanism these variants cause these phenotypes. Knowledge of these intermediate steps is crucial to understand pathogenesis, while also providing leads for potential pharmacological intervention. Here we relied upon natural human genetic variation to identify effects of these variants on trans-gene expression (expression quantitative trait locus mapping, eQTL) in whole peripheral blood from 1,469 unrelated individuals. We looked at 1,167 published trait- or disease-associated SNPs and observed trans-eQTL effects on 113 different genes, of which we replicated 46 in monocytes of 1,490 different individuals and 18 in a smaller dataset that comprised subcutaneous adipose, visceral adipose, liver tissue, and muscle tissue. HLA single-nucleotide polymorphisms (SNPs) were 10-fold enriched for trans-eQTLs: 48% of the trans-acting SNPs map within the HLA, including ulcerative colitis susceptibility variants that affect plausible candidate genes AOAH and TRBV18 in trans. We identified 18 pairs of unlinked SNPs associated with the same phenotype and affecting expression of the same trans-gene (21 times more than expected, P<10(-16)). This was particularly pronounced for mean platelet volume (MPV): Two independent SNPs significantly affect the well-known blood coagulation genes GP9 and F13A1 but also C19orf33, SAMD14, VCL, and GNG11. Several of these SNPs have a substantially higher effect on the downstream trans-genes than on the eventual phenotypes, supporting the concept that the effects of these SNPs on expression seems to be much less multifactorial. Therefore, these trans-eQTLs could well represent some of the intermediate genes that connect genetic variants with their eventual complex phenotypic outcomes.     

Lithium treatment of APPSwDI/NOS2-/- mice leads to reduced hyperphosphorylated tau, increased amyloid deposition and altered inflammatory phenotype

Lithium is an anti-psychotic that has been shown to prevent the hyperphosphorylation of tau protein through the inhibition of glycogen-synthase kinase 3-beta (GSK3β). We recently developed a mouse model that progresses from amyloid pathology to tau pathology and neurodegeneration due to the genetic deletion of NOS2 in an APP transgenic mouse; the APPSwDI/NOS2-/- mouse. Because this mouse develops tau pathology, amyloid pathology and neuronal loss we were interested in the effect anti-tau therapy would have on amyloid pathology, learning and memory. We administered lithium in the diets of APPSwDI/NOS2-/- mice for a period of eight months, followed by water maze testing at 12 months of age, immediately prior to sacrifice. We found that lithium significantly lowered hyperphosphorylated tau levels as measured by Western blot and immunocytochemistry. However, we found no apparent neuroprotection, no effect on spatial memory deficits and an increase in histological amyloid deposition. Aβ levels measured biochemically were unaltered. We also found that lithium significantly altered the neuroinflammatory phenotype of the brain, resulting in enhanced alternative inflammatory response while concurrently lowering the classical inflammatory response. Our data suggest that lithium may be beneficial for the treatment of tauopathies but may not be beneficial for the treatment of Alzheimer's disease.