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  • 1.

    【2hr】Mechanistic Insights into Colorectal Cancer Phenomics from Fundamental and Organotypic Model Studies

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    机译 从基本面和器官型模型研究到结直肠癌表型的力学见解。
    摘要：Colorectal cancer (CRC) diagnosis and prognostic stratification are based on histopathologic assessment of cell or nuclear pleomorphism, aberrant mitotic figures, altered glandular architecture, and other phenomic abnormalities. This complexity is driven by oncogenic perturbation of tightly coordinated spatiotemporal signaling to disrupt multiple scales of tissue organization. This review clarifies molecular and cellular mechanisms underlying common CRC histologic features and helps understand how the CRC genome controls core aspects of tumor aggressiveness. It further explores a spatiotemporal framework for CRC phenomics based on regulation of living cells in fundamental and organotypic model systems. The review also discusses tissue homeostasis, considers distinct classes of oncogenic perturbations, and evolution of cellular or multicellular cancer phenotypes. It further explores the molecular controls of cribriform, micropapillary, and high-grade CRC morphology in organotypic culture models and assesses relevant translational studies. In addition, the review delves into complexities of morphologic plasticity whereby a single molecular signature generates heterogeneous cancer phenotypes, and, conversely, morphologically homogeneous tumors show substantive molecular diversity. Principles outlined may aid mechanistic interpretation of omics data in a setting of cancer pathology, provide insight into CRC consensus molecular subtypes, and better define principles for CRC prognostic stratification.
  • 2.

    【2hr】Correction

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    机译 更正
    • 作者：
    • 刊名：The American Journal of Pathology
    • 2018年第8期
    摘要：
  • 3.

    【2hr】ELABELA/APELA Levels Are Not Decreased in the Maternal Circulation or Placenta among Women with Preeclampsia

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    机译 子痫前期妇女的孕产妇循环或胎盘中的ELABELA / APELA水平没有降低
    摘要：The genetic deletion of apelin receptor early endogenous ligand (Elabela; official name APELA) produces a preeclampsia-like phenotype in mice. However, evidence linking ELABELA with human disease is lacking. Therefore, we measured placental mRNA and circulating ELABELA in human samples. ELABELA mRNA (measured by RNA sequencing) was unchanged in 82 preeclamptic placentas compared with 82 matched controls (mean difference, 0.53%; 95% CI, −25.9 to 27.0; P = 0.78). We measured circulating ELABELA in 32 women with preterm preeclampsia (delivered at <34 weeks' gestation) and 32 matched controls sampled at the same gestational age. There was no difference in circulating ELABELA concentrations in the preeclamptic cohort compared with controls (median, 28.5 pg/mL; 95% CI, 5.3 to 63.2 versus median, 20.5 pg/mL; 95% CI, 9.2 to 58.0, respectively); the median difference was 8.0 pg/mL (95% CI, −17.7 to 12.1; P = 0.43). In contrast, soluble FLT1 (a protein with an established association with preeclampsia) mRNA was increased in placental tissue (mean difference, 34.9%; 95% CI, 16.6 to 53.1; P = 0.001), and circulating concentrations were 16.8-fold higher among the preeclamptic cohort (P < 0.0001). In conclusion, we were able to recapitulate the association between circulating soluble FLT1 and preeclampsia, but there was no association with ELABELA. The speculated clinical relevance of observations in the murine model linking ELABELA to preeclampsia likely are incorrect.
  • 4.

    【2hr】Placental fractalkine is up-regulated in severe early onset preeclampsia

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    机译 严重的早发先兆子痫中胎盘中的fractalkine上调
    摘要：The pathogenesis of preeclampsia includes the release of placental factors into the maternal circulation inducing an inflammatory environment in the mother. One of the factors may be the pro-inflammatory chemokine fractalkine, which is expressed in the syncytiotrophoblast of human placenta, from where it is released into the maternal circulation by constitutive shedding. We examined whether placental fractalkine is up-regulated in severe early onset preeclampsia and whether the pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin-6 are able to increase the expression of fractalkine. Gene expression analysis, ELISA, and immunohistochemistry consistently showed increased fractalkine expression in placentas from severe early onset preeclampsia, compared to gestational age-matched controls. Expression of the metalloproteinases ADAM10 and ADAM17, which convert transmembrane fractalkine into the soluble form, was significantly increased in these cases. Incubation of first trimester placental explants with TNF-α provoked a significant increase in fractalkine expression and release of the soluble form, whereas interleukin-6 had no effect. TNF-α-mediated up-regulation of placental fractalkine was reversed in the presence of the Aspirin-derivative salicylate, which impaired activation of NF-κB p65 in TNF-α-treated explants. Based on data from placental explants we suggest that increased maternal TNF-α may up-regulate the expression and release of placental fractalkine, which in turn may contribute to an exaggerated systemic inflammatory response in preeclampsia.
  • 5.

    【2hr】Micro-CT Imaging of Tumor Angiogenesis: Quantitative Measures Describing Micromorphology and Vascularization

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    机译 肿瘤血管生成的微CT成像：描述微观形态和血管化的定量测量。
    摘要：Angiogenesis is a hallmark of cancer, and its noninvasive visualization and quantification are key factors for facilitating translational anticancer research. Using four tumor models characterized by different degrees of aggressiveness and angiogenesis, we show that the combination of functional in vivo and anatomical ex vivo X-ray micro-computed tomography (μCT) allows highly accurate quantification of relative blood volume (rBV) and highly detailed three-dimensional analysis of the vascular network in tumors. Depending on the tumor model, rBV values determined using in vivo μCT ranged from 2.6% to 6.0%, and corresponds well with the values assessed using IHC. Using ultra-high-resolution ex vivo μCT, blood vessels as small as 3.4 mm and vessel branches up to the seventh order could be visualized, enabling a highly detailed and quantitative analysis of the three-dimensional micromorphology of tumor vessels. Microvascular parameters such as vessel size and vessel branching correlated very well with tumor aggressiveness and angiogenesis. In rapidly growing and highly angiogenic A431 tumors, the majority of vessels were small and branched only once or twice, whereas in slowly growing A549 tumors, the vessels were much larger and branched four to seven times. Thus, we consider that combining highly accurate functional with highly detailed anatomical μCT is a useful tool for facilitating high-throughput, quantitative, and translational (anti-) angiogenesis and antiangiogenesis research.
  • 6.

    【2hr】Villin Expression Is Frequently Lost in Poorly Differentiated Colon Cancer

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    机译 在分化差的结肠癌中，Villin表达经常丢失
    摘要：Colorectal cancers (CRCs) are classified as having microsatellite instability (MSI) or chromosomal instability (CIN); herein termed microsatellite stable (MSS). MSI colon cancers frequently display a poorly differentiated histology for which the molecular basis is not well understood. Gene expression and immuno-histochemical profiling of MSS and MSI CRC cell lines and tumors revealed significant down-regulation of the intestinal-specific cytoskeletal protein villin in MSI colon cancer, with complete absence in 62% and 17% of MSI cell lines and tumors, respectively. Investigation of 577 CRCs linked loss of villin expression to poorly differentiated histology in MSI and MSS tumors. Furthermore, mislocalization of villin from the membrane was prognostic for poorer outcome in MSS patients. Loss of villin expression was not due to coding sequence mutations, epigenetic inactivation, or promoter mutation. Conversely, in transient transfection assays villin promoter activity reflected endogenous villin expression, suggesting transcriptional control. A screen of gut-specific transcription factors revealed a significant correlation between expression of villin and the homeobox transcription factor Cdx-1. Cdx-1 overexpression induced villin promoter activity, Cdx-1 knockdown down-regulated endogenous villin expression, and deletion of a key Cdx-binding site within the villin promoter attenuated promoter activity. Loss of Cdx-1 expression in CRC lines was associated with Cdx-1 promoter methylation. These findings demonstrate that loss of villin expression due to Cdx-1 loss is a feature of poorly differentiated CRCs.
  • 7.

    【2hr】Therapeutic dosing of FTY720 (Fingolimod) prevents cell infiltrate, rapidly suppresses ocular inflammation and maintains blood-ocular barrier

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    机译 FTY720（芬戈莫德）的治疗剂量可防止细胞浸润，快速抑制眼部炎症并维持血-眼屏障
    摘要：Fingolimod (FTY720) is a FDA-approved therapeutic, with efficacy demonstrated in experimental models of MS, and phase III human MS trials. FTY720 prevents T-cell migration to inflammatory sites, by down-regulating expression of the sphingosine-1 phosphate receptor normally required for egress from secondary lymphoid tissue. Experimental autoimmune uveoretinitis (EAU) serves as a preclinical model of human uveitis, permitting assessment of immunotherapeutic efficacy. Murine EAU is initiated by activation of retinal–antigen specific CD4+ T cells that infiltrate the eye, and previous studies demonstrate that high dose FTY720 treatment administered before disease onset reduces ocular infiltrate within hours of administration and suppresses clinico-pathological expression of EAU. The present study investigates the efficacy of FTY720 treatment for established disease. Single dose treatment is effective and its immunosuppressive ability is maintained through a dose range of FTY720, demonstrating significant and rapid reduction in the CD4+ cell infiltrate at clinically relevant therapeutic doses. Furthermore, a repeated treatment regimen using a comparable dose to current MS patient protocols significantly reduces infiltrate within 24 hours of administration, and importantly repeated doses do not compromise the vascular integrity of the blood-ocular barrier. Upon withdrawal of FTY720, drug induced remission is lost and recrudescence of clinical disease is observed. These results support the great therapeutic potential for FTY720 as an acute rescue therapy for the treatment of ocular immune-mediated inflammation.
  • 8.

    【2hr】Rheumatoid Arthritis Synovium Contains Two Subsets of CD83−DC-LAMP− Dendritic Cells with Distinct Cytokine Profiles

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    机译 类风湿关节炎滑膜含有两个亚群的CD83-DC-LAMP-树突状细胞，具有不同的细胞因子谱。
    摘要：Dendritic cells (DCs) have been proposed to play a pivotal role in the initiation and perpetuation of rheumatoid arthritis (RA) by presentation of arthritogenic antigens to T cells. We investigated the in vivo characteristics of two major DC subsets, myeloid DCs (mDCs) and plasmacytoid DCs (pDCs), in RA synovial tissue (ST) by measuring their frequency, phenotype, distribution, and cytokine expression. ST was obtained by arthroscopy from 20 RA, 8 psoriatic arthritis, and 10 inflammatory osteoarthritis patients. Levels of CD1c+ mDCs and CD304+ pDCs present in ST were quantified by digital image analysis, and their distribution was assessed by double immunolabeling with antibodies against CD3 and CD8. The maturation status and cytokine profile of mDCs and pDCs were quantified by double-immunofluorescence microscopy. In RA patients, the number of CD304+ pDCs exceeded that of CD1c+ mDCs, with the majority of infiltrating DCs being CD83− or DC-LAMP−. Synovial pDC numbers were especially increased in RA patients who were positive for rheumatoid factor and anti-citrullinated peptide antibody. mDCs and pDCs were localized adjacent to lymphocyte aggregates. In ST from RA patients, both mDCs and pDCs expressed interleukin (IL)-15. IL-18 and interferon (IFN)-α/β were mainly expressed by pDCs whereas IL-12p70 and IL-23p19 expression was predominant in mDCs. These data characterize the phenotypes of mDCs and pDCs in inflammatory synovitis and define for the first time the cytokine expression profile of these DC subsets.
  • 9.

    【2hr】Heterogeneity of Human Macrophages in Culture and in Atherosclerotic Plaques

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    机译 人类巨噬细胞在培养物中和动脉粥样硬化斑块中的异质性
    摘要：Research suggests that monocytes differentiate into unique lineage-determined macrophage subpopulations in response to the local cytokine environment. The present study evaluated the atherogenic potential of two divergent lineage-determined human monocyte-derived macrophage subpopulations. Monocytes were differentiated for 7 days in the presence of alternative macrophage development cytokines: granulocyte-macrophage colony-stimulating factor to produce granulocyte-macrophage-CSF macrophages (GM-Mac), or macrophage colony-stimulating factor (M-CSF) to produce M-Mac. Gene chip analyses of three monocyte donors demonstrated differential expression of inflammatory and cholesterol homeostasis genes in the macrophage subpopulations. Quantitative PCR confirmed a fivefold elevation in the expression of genes that promote reverse cholesterol transport (PPAR-γ, LXR-α, and ABCG1) and macrophage emigration from lesions (CCR7) in GM-Mac compared to that in M-Mac. Immunocytochemistry confirmed enhanced expression of the proinflammatory marker CD14 in M-Mac relative to GM-Mac. M-Mac spontaneously accumulated cholesterol when incubated with unmodified low-density lipoprotein whereas GM-Mac only accumulated similar levels of cholesterol after protein kinase C activation. Immunostained human coronary arteries showed that macrophages with similar antigen expression to that of M-Mac (CD68+/CD14+) were predominant within atherosclerotic lesions whereas macrophages with antigen expression similar to GM-Mac (CD68+/CD14−) were predominant in areas devoid of disease. The identification of macrophage subpopulations with different gene expression patterns and, thus, different potentials for promoting atherosclerosis has important experimental and clinical implications and could prove to be a valuable finding in developing therapeutic interventions in diseases dependent on macrophage function.
  • 10.

    【2hr】Antigen-Induced Pten Gene Deletion in T Cells Exacerbates Neuropathology in Experimental Autoimmune Encephalomyelitis

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    机译 T细胞中抗原诱导的Pten基因缺失加剧了实验性自身免疫性脑脊髓炎的神经病理学
    摘要：The Pten tumor suppressor gene is critical for normal intrathymic development of T cells; however, its role in mature antigen-activated T cells is less well defined. A genetically crossed mouse line, Ptenfl/fl GBC, in which Pten gene deletions could be primarily confined to antigen-activated CD8+ T cells, enabled us to evaluate the consequences of Pten loss on the course of experimental autoimmune encephalomyelitis. Compared with Ptenfl/fl controls, myelin oligodendrocyte glycoprotein (MOG) peptide-immunized Ptenfl/fl GBC mice developed more severe and protracted disease. This was accompanied by increased spinal cord white matter myelin basic protein depletion and axonal damage, as well as a striking persistence of macrophage and granzyme B-expressing cellular neuroinfiltrates in the chronic phase of the disease. This persistence may be explained by the observation that anti-CD3 activated Ptenfl/fl GBC T cells were more resistant to proapoptotic stimuli. Consistent with the predicted consequences of Pten loss, purified CD8+ T cells from Ptenfl/fl GBC mice displayed augmented proliferative responses to anti-T-cell receptor stimulation, and MOG-primed Ptenfl/fl GBC T cells exhibited a reduced activation threshold to MOG peptide. Ptenfl/fl GBC mice also developed atypical central nervous system disease, manifested by prominent cervical cord and forebrain involvement. Collectively, our findings indicate that the phosphatidylinositol 3-kinase signaling pathway is an essential regulator of CD8+ T-cell effector function in experimental autoimmune encephalomyelitis.
  • 11.

    【2hr】Zinc Supplementation Enhances Hepatic Regeneration by Preserving Hepatocyte Nuclear Factor-4α in Mice Subjected to Long-Term Ethanol Administration

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    机译 锌的补充通过长期接受乙醇的小鼠体内肝细胞核因子4α的保存来增强肝脏的再生。
    摘要：Alcoholic liver disease is associated with sustained liver damage and impaired regeneration, as well as significant zinc deficiency. This study was undertaken to examine whether dietary zinc supplementation could improve liver regeneration by increasing the expression of genes involved in hepatic cellular proliferation in a mouse model of alcoholic liver disease. Adult 129S6 mice fed an ethanol-containing liquid diet for 6 months developed alcoholic liver disease as measured by serum alanine transferase activity and histopathological changes. Zinc supplementation to ethanol-exposed mice enhanced liver regeneration as indicated by increased numbers of proliferation cell nuclear antigen (PCNA)-positive and bromodeoxyuridine (BrdU)-labeled hepatocytes. Zinc-enhanced liver regeneration was associated with an increase in hepatocyte nuclear factor-4α (HNF-4α), a liver-enriched, zinc-finger transcription factor. Studies using cultured HepG2 cells showed that zinc deficiency suppressed cell proliferation and cell proliferation-related proteins, including hepatocyte growth factor (HGF), insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 1 (IGFBP1), metallothionein (MT), and cyclin D1, as well as HNF-4α. HNF-4α gene silencing inhibited cell proliferation in association with decreased protein levels of IGF-I, IGFBP1, MT, and cyclin D1. The present study provides evidence that zinc supplementation enhances liver regeneration at least in part by HNF-4α through the up-regulation of cell proliferation-related proteins, suggesting that dietary zinc supplementation may have beneficial effects in alcoholic liver disease.
  • 12.

    【2hr】Lymphadenopathy in a Novel Mouse Model of Bartonella-Induced Cat Scratch Disease Results from Lymphocyte Immigration and Proliferation and Is Regulated by Interferon-α/β

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    机译 淋巴结病在巴尔通体诱导的猫抓病的新型小鼠模型中的结果来自淋巴细胞的迁移和增殖，并受干扰素-α/β的调节
    摘要：In immunocompetent humans, cat scratch disease (CSD) is elicited by the Gram-negative bacterium Bartonella henselae and is characterized by a benign regional lymphadenopathy, the pathogenesis of which is poorly understood. Here, we describe a novel mouse model of Bartonella-induced CSD-like disease that allowed us to investigate the mechanisms leading to lymphadenopathy in vivo. In wild-type mice, a subcutaneous inoculation of either viable or inactivated B. henselae led to a strong swelling of the draining lymph node, which was long-lasting despite the rapid elimination of the bacteria. Carboxyfluorescein- and bromodesoxyuridine-labeling experiments showed that lymph node enlargement resulted from modified immigration and enhanced proliferation of lymphocytes, preferentially of B cells. A comparative analysis of B. henselae and the rodent pathogen B. grahamii in wild-type versus interferon-α/β-receptor I chain-deficient mice revealed that interferon-α/β is not only differentially induced by these two Bartonella species but also exerts an inhibitory effect on the development of lymphadenopathy both in vitro and in vivo. These data demonstrate that the lymphadenopathy of human CSD can be reproduced and studied in a mouse model and provide the first insights into the underlying immunological mechanisms.
  • 13.

    【2hr】Ultraviolet B Suppresses Immunity by Inhibiting Effector and Memory T Cells

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    机译 紫外线B通过抑制效应细胞和记忆T细胞抑制免疫力
    摘要：Contact hypersensitivity is a T-cell-mediated response to a hapten. Exposing C57BL/6 mice to UV B radiation systemically suppresses both primary and secondary contact hypersensitivity responses. The effects of UVB on in vivo T-cell responses during UVB-induced immunosuppression are unknown. We show here that UVB exposure, before contact sensitization, inhibits the expansion of effector CD4+ and CD8+ T cells in skin-draining lymph nodes and reduces the number of CD4+ and IFN-γ+ CD8+ T cells infiltrating challenged ear skin. In the absence of UVB, at 10 weeks after initial hapten exposure, the ear skin of sensitized mice was infiltrated by dermal effector memory CD8+ T cells at the site of challenge. However, if mice were previously exposed to UVB, this cell population was absent, suggesting an impaired development of peripheral memory T cells. This finding occurred in the absence of UVB-induced regulatory CD4+ T cells and did not involve prostaglandin E2, suggesting that the importance of these two factors in mediating or initiating UVB-induced immunosuppression is dependent on UVB dose. Together these data indicate that in vivo T-cell responses are prone to immunoregulation by UVB, including a novel effect on both the activated T-cell pool size and the development of memory T cells in peripheral compartments.
  • 14.

    【2hr】A Key Claudin Extracellular Loop Domain is Critical for Epithelial Barrier Integrity

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    机译 关键的克劳丁细胞外环域对于上皮屏障完整性至关重要
    摘要：Intercellular tight junctions (TJs) regulate epithelial barrier properties. Claudins are major structural constituents of TJs and belong to a large family of tetra-spanning membrane proteins that have two predicted extracellular loops (ELs). Given that claudin-1 is widely expressed in epithelia, we further defined the role of its EL domains in determining TJ function. The effects of several claudin-1 EL mimetic peptides on epithelial barrier structure and function were examined. Incubation of model human intestinal epithelial cells with a 27-amino acid peptide corresponding to a portion of the first EL domain (Cldn-153–80) reversibly interfered with epithelial barrier function by inducing the rearrangement of key TJ proteins: occludin, claudin-1, junctional adhesion molecule-A, and zonula occludens-1. Cldn-153–80 associated with both claudin-1 and occludin, suggesting both the direct interference with the ability of these proteins to assemble into functional TJs and their close interaction under physiological conditions. These effects were specific for Cldn-153–80, because peptides corresponding to other claudin-1 EL domains failed to influence TJ function. Furthermore, the oral administration of Cldn-153–80 to rats increased paracellular gastric permeability. Thus, the identification of a critical claudin-1 EL motif, Cldn-153–80, capable of regulating TJ structure and function, offers a useful adjunct to treatments that require drug delivery across an epithelial barrier.
  • 15.

    【2hr】Revisiting the Koebner Phenomenon

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    机译 重温科布纳现象
    摘要：Nerve growth factor (NGF) influences the key pathological events of psoriasis: keratinocyte proliferation, angiogenesis, and T-cell activation. We have systematically examined the kinetics of NGF expression, keratinocyte proliferation, and migration of T lymphocytes in the epidermis in Koebner-induced developing psoriatic plaques. In skin traumatized by the tape-stripping method (n = 12), a marked up-regulation of NGF in Koebner-positive lesions (n = 7) was observed 24 hours after trauma. Synthesis of NGF reached its maximum level in the 2nd week. Furthermore, cultured keratinocytes from nonlesional skin of psoriasis patients produced 10 times higher levels of NGF compared with keratinocytes from healthy individuals. To substantiate the in vivo effect of NGF secreted by keratinocytes in psoriatic plaques, we studied psoriatic plaques and normal human skin in a SCID-human skin xenograft model. The transplanted psoriatic plaques demonstrated marked proliferation of NGF-R (p75)-positive nerve fibers compared with only a few nerves in the transplanted normal human skin. Our results demonstrate that 1) in a developing psoriatic lesion, up-regulation of NGF together with keratinocyte proliferation are early events and precede epidermotropism of T lymphocytes; 2) keratinocytes in patients with psoriasis are primed to produce elevated levels of NGF; and 3) NGF synthesized by these keratinocytes is functionally active.
  • 16.

    【2hr】Blockade of Endothelinergic Receptors Prevents Development of Proliferative Vitreoretinopathy in Mice

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    机译 内皮素能受体的阻滞阻止了小鼠增殖性玻璃体视网膜病变的发展
    摘要：Proliferative vitreoretinopathy (PVR) is characterized by severe glial remodeling. Glial activation and proliferation that occur in brain diseases are modulated by endothelin-1 (ET-1) and its receptor B (ETR-B). Because retinal astrocytes contain ET-1 and express ETR-B, we studied the changes of these molecules in an experimental mouse model of PVR and in human PVR. Both ET-1 and ETR-B immunoreactivities increased in mouse retina after induction of PVR with dispase. Epi- and subretinal outgrowths also displayed these immunoreactivities in both human and experimental PVR. Additionally, myofibroblasts and other membranous cell types showed both ET-1 and ETR-B immunoreactivities. In early stages of experimentally induced PVR, prepro-ET-1 and ETR-B mRNA levels increased in the retina. These mRNA levels also increased after retinal detachment (RD) produced by subretinal injection. Treatment of mice with tezosentan, an antagonist of endothelinergic receptors, reduced the histopathological hallmarks of dispase-induced PVR: retinal folding, epiretinal outgrowth, and gliosis. Our findings in human and in dispase-induced PVR support the involvement of endothelinergic pathways in retinal glial activation and the phenotypic transformations that underlie the growth of membranes in this pathology. Elucidating these pathways further will help to develop pharmacological treatments to prevent PVR. In addition, the presence of ET-1 and ETR-B in human fibrous membranes suggests that similar treatments could be helpful after PVR has been established.
  • 17.

    【2hr】Age-Related Changes in Bone Morphology Are Accelerated in Group VIA Phospholipase A2 (iPLA2β)-Null Mice

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    机译 VIA组磷脂酶A2（iPLA2β）-空小鼠的年龄与骨形态变化有关。
    摘要：Phospholipases A2 (PLA2) hydrolyze the sn−2 fatty acid substituent, such as arachidonic acid, from phospholipids, and arachidonate metabolites are recognized mediators of bone modeling. We have previously generated knockout (KO) mice lacking the group VIA PLA2 (iPLA2β), which participates in a variety of signaling events; iPLA2β mRNA is expressed in bones of wild-type (WT) but not KO mice. Cortical bone size, trabecular bone volume, bone mineralizing surfaces, and bone strength are similar in WT and KO mice at 3 months and decline with age in both groups, but the decreases are more pronounced in KO mice. The lower bone mass phenotype observed in KO mice is not associated with an increase in osteoclast abundance/activity or a decrease in osteoblast density, but is accompanied by an increase in bone marrow fat. Relative to WT mice, undifferentiated bone marrow stromal cells (BMSCs) from KO mice express higher levels of PPAR-γ and lower levels of Runx2 mRNA, and this correlates with increased adipogenesis and decreased osteogenesis in BMSCs from these mice. In summary, our studies indicate that age-related losses in bone mass and strength are accelerated in iPLA2β-null mice. Because adipocytes and osteoblasts share a common mesenchymal stem cell origin, our findings suggest that absence of iPLA2β causes abnormalities in osteoblast function and BMSC differentiation and identify a previously unrecognized role of iPLA2β in bone formation.
  • 18.

    【2hr】Cortical Demyelination Is Prominent in the Murine Cuprizone Model and Is Strain-Dependent

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    机译 皮质脱髓鞘作用在鼠铜酮模型中很明显，并且依赖于应变
    摘要：The cuprizone model of toxic demyelination in the central nervous system is commonly used to investigate the pathobiology of remyelination in the corpus callosum. However, in human demyelinating diseases such as multiple sclerosis, recent evidence indicates a considerable amount of cortical demyelination in addition to white matter damage. Therefore, we have investigated cortical demyelination in the murine cuprizone model. To induce demyelination, C57BL/6 mice were challenged with 0.2% cuprizone feeding for 6 weeks followed by a recovery phase of 6 weeks with a cuprizone-free diet. In addition to the expected demyelination in the corpus callosum, the cortex of C57BL/6 mice was completely demyelinated after 6 weeks of cuprizone feeding. After withdrawal of cuprizone the cortex showed complete remyelination similar to that in the corpus callosum. When C57BL/6 mice were fed cuprizone for a prolonged period of 12 weeks, cortical remyelination was significantly delayed. Because interstrain differences have been described, we also investigated the effects of cuprizone on cortical demyelination in BALB/cJ mice. In these mice, cortical demyelination was only partial. Moreover, cortical microglia accumulation was markedly increased in BALB/cJ mice, whereas microglia were absent in the cortex of C57BL/6 mice. In summary, our results show that cuprizone feeding is an excellent model in which to study cortical demyelination and remyelination, including contributing genetic factors represented by strain differences.
  • 19.

    【2hr】Stimulus-Dependent Impairment of the Neutrophil Oxidative Burst Response in Lactoferrin-Deficient Mice

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    机译 乳铁蛋白缺乏症小鼠中性粒细胞氧化爆发反应的刺激依赖性损伤。
    摘要：Lactoferrin (LF) is an iron-binding protein found in milk, mucosal secretions, and the secondary granules of neutrophils in which it is considered to be an important factor in the innate immune response against microbial infections. Moreover, LF deficiency in the secondary granules of neutrophils has long been speculated to contribute directly to the hypersusceptibility of specific granule deficiency (SGD) patients to severe, life-threatening bacterial infections. However, the exact physiological significance of LF in neutrophil-mediated host defense mechanisms remains controversial and has not yet been clearly established in vivo using relevant animal models. In this study, we used lactoferrin knockout (LFKO) mice to directly address the selective role of LF in the host defense response of neutrophils and to determine its contribution, if any, to the phenotype of SGD. Neutrophil maturation, migration, phagocytosis, granule release, and antimicrobial response to bacterial challenge were unaffected in LFKO mice. Interestingly, a stimulus-dependent defect in the oxidative burst response of LFKO neutrophils was observed in that normal activation was seen in response to opsonized bacteria whereas an impaired response was evident after phorbol myristate-13-acetate stimulation. Taken together, these results indicate that although LF deficiency alone is not a primary cause of the defects associated with SGD, this protein does play an immunomodulatory role in the oxidative burst response of neutrophils.
  • 20.

    【2hr】Liver Repopulation and Carcinogenesis: Two Sides of the Same Coin?

    包量

    机译 肝脏繁殖与致癌作用：同一枚硬币的两个方面？
    摘要：Liver repopulation by transplanted normal hepatocytes has been described in a number of experimental settings. Extensive repopulation can also occur from the selective proliferation of endogenous normal hepatocytes, both in experimental animals and in the human liver. This review highlights the intriguing association between clinical and experimental conditions related to liver repopulation and an increased risk for development of hepatocellular carcinoma. It is suggested that any microenvironment that is able to sustain the clonal growth of normal transplanted (or endogenous) hepatocytes is also geared to select for the emergence of rare resistant cells with an altered phenotype. Whereas the first pathway leads to liver repopulation with normal histology, the latter results in the growth of focal proliferative lesions and carries an increased risk of neoplastic disease. The implications of this association are discussed, both in terms of pathogenetic significance and possible therapeutic exploitation.
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