We present the AGEMAP (Atlas of Gene Expression in Mouse Aging Project) gene expression database, which is a resource that catalogs changes in gene expression as a function of age in mice. The AGEMAP database includes expression changes for 8,932 genes in 16 tissues as a function of age. We found great heterogeneity in the amount of transcriptional changes with age in different tissues. Some tissues displayed large transcriptional differences in old mice, suggesting that these tissues may contribute strongly to organismal decline. Other tissues showed few or no changes in expression with age, indicating strong levels of homeostasis throughout life. Based on the pattern of age-related transcriptional changes, we found that tissues could be classified into one of three aging processes: (1) a pattern common to neural tissues, (2) a pattern for vascular tissues, and (3) a pattern for steroid-responsive tissues. We observed that different tissues age in a coordinated fashion in individual mice, such that certain mice exhibit rapid aging, whereas others exhibit slow aging for multiple tissues. Finally, we compared the transcriptional profiles for aging in mice to those from humans, flies, and worms. We found that genes involved in the electron transport chain show common age regulation in all four species, indicating that these genes may be exceptionally good markers of aging. However, we saw no overall correlation of age regulation between mice and humans, suggesting that aging processes in mice and humans may be fundamentally different.

There are currently no effective therapies for metastatic melanoma and targeted immunotherapy results in the remission of only a very small percentage of tumors. In this study, we show that the noncanonical Wnt ligand, Wnt5A, can increase melanoma metastasis in vivo while down-regulating the expression of tumor-associated antigens important in eliciting CTL responses (e.g., MART-1, GP100, and tyrosinase). Melanosomal antigen expression is governed by MITF, PAX3, and SOX10 and is inhibited upon signal transducers and activators of transcription 3 (STAT3) activation, via decreases in PAX3 and subsequently MITF expression. Increasing Wnt5A in Wnt5A-low cells activated STAT3, and STAT3 was decreased upon Wnt5A knockdown. Downstream targets such as PAX3, MITF, and MART-1 were also affected by Wnt5A treatment or knockdown. Staining of a melanoma tissue array also highlighted the inverse relationship between MART-1 and Wnt5A expression. PKC activation by phorbol ester mimicked Wnt5A effects, and Wnt5A treatment in the presence of STAT3 or PKC inhibitors did not lower MART-1 levels. CTL activation studies showed that increases in Wnt5A correspond to decreased CTL activation and vice versa, suggesting that targeting Wnt5A before immunotherapy may lead to the enhancement of current targeted immunotherapy for patients with metastatic melanoma.

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Dexamethasone (DM) is a synthetic member of the glucocorticoid (GC) class of hormones that possesses antiinflammatory and immunosuppressant activity and is commonly used to treat chronic inflammatory disorders, severe allergies, and other disease states. Although GCs are known to mediate welldefined transcriptional effects via GC receptors (GCR), there is increasing evidence that GCs also initiate rapid nongenomic signaling events in a variety of cell types. Here, we report that DM induces the phosphorylation of Lck IntroductionGlucocorticoids (GCs) are used to treat diseases with an inflammatory or immune-mediated component, including autoimmune diseases, graft rejection, and leukemia. GCs act via the T-cell intracellular GC receptor (GCR) and may negatively regulate the expression of numerous genes associated with proinflammatory cytokine signaling. 1,2 This inhibition of gene transcription appears to result from the ability of the GC/GCR complex to interfere with the activity of numerous transcription factors, either by binding to negative regulatory elements in the promoter region or through protein/protein interactions, impeding the ability of these factors to positively direct gene transcription. 3 In addition to these genomic effects, several studies have also described nongenomic, rapid effects of GCs on immune cells. [4][5][6][7] Dexamethasone (DM) can attenuate the early events of the T-cell receptor (TCR)-induced signaling cascade, including the activation of Src kinases via the GCR. GCRdeficient Jurkat cells and human T cells treated with the GCR blocker, Ru486, during cell activation failed to demonstrate any inhibition in kinase activation in response to DM. Interestingly, many of the inhibitory effects of GC have been observed in activated human or rodent T cells and immune cell subpopulations; however, the effects of DM on resting T cells are unclear.CXCR4, a chemokine receptor specific for the chemokine ligand, CXCL12, is expressed on leukocytes and is involved in the recirculation of naive lymphocytes into lymphoid tissue. 8 This receptor also plays a role in the retention of stem cells, differentiating B cells and neutrophils within bone marrow 9 and controls B-cell positioning within lymph nodes, where its expression is regulated by interleukin-4. 10 CXCR4 has been found to play a critical role in thymocyte chemotaxis and apoptosis 11 as well as thymic development. 12 CXCL12 was found to counteract the effects of DM on the apoptosis of CD4 ϩ CD8 ϩ T cells. Interestingly, several reports have also demonstrated that exposure of T-cell lines to GC can up-regulate cell surface CXCR4 expression. 13,14 Signals delivered through CXCR4-CXCL12 interactions result in potent chemotactic and pro-adhesive signals facilitating T-and B-lymphocyte migration. [15][16][17] Several reports have suggested that the activation of the Src kinase, Lck, on treatment of T cells with CXCL12 may be involved in orchestrating the downstream signals necessary for chemotaxis. 18,19 CXCR4 physically associates with the TC...

BackgroundCXCL12 is a pleiotropic chemokine involved in multiple different processes such as immune regulation, inflammatory responses, and cancer development. CXCL12 is also a potent chemokine involved in chemoattraction of T cells to the site of infection or inflammation. Mammalian target of rapamycin (mTOR) is a serine-threonine kinase that modulates different cellular processes, such as metabolism, nutrient sensing, protein translation, and cell growth. The role of mTOR in CXCL12-mediated resting T cell migration has yet to be elucidated.Methodology/Principal FindingsRapamycin, an inhibitor of mTOR, significantly inhibits CXCL12 mediated migration of both primary human resting T cells and human T cell leukemia cell line CEM. p70S6K1, an effector molecule of mTOR signaling pathway, was knocked down by shRNA in CEM cells using a lentiviral gene transfer system. Using p70S6K1 knock down cells, we demonstrate the role of mTOR signaling in T cell migration both in vitro and in vivo.ConclusionsOur data demonstrate a new role for mTOR in CXCL12-induced T cell migration, and enrich the current knowledge regarding the clinical use of rapamycin.

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system (CNS) involving demyelinating and neurodegenerative processes. Several of the major pathological CNS alterations and behavioral deficits of MS are recapitulated in the experimental autoimmune encephalitis (EAE) mouse model in which the disease process is induced by administration of myelin peptides. Development of EAE requires infiltration of inflammatory cytokine-generating monocytes and macrophages, and auto-reactive T cells, into the CNS. Very late antigen-4 (VLA-4, α4β1) is an integrin molecule that plays a role in inflammatory responses by facilitating the migration of leukocytes across the blood-brain barrier during inflammatory disease, and antibodies against VLA-4 exhibit therapeutic efficacy in mouse and monkey MS models. Here we report that the tellurium compound AS101 (ammonium trichloro (dioxoethylene-o,o’) tellurate) ameliorates EAE by inhibiting monocyte ant T-cell infiltration into the CNS. CD49d is an alpha subunit of the VLA-4 (α4β1) integrin. During the peak stage of EAE, AS101 treatment effectively ameliorated the disease process by reducing the number of CD49d+ inflammatory monocyte/macrophage cells in the spinal cord. AS101 treatment markedly reduced the pro-inflammatory cytokine levels, while increasing anti-inflammatory cytokine levels. In contrast, AS101 treatment did not affect the peripheral populations of CD11b+ monocytes and macrophages. AS101 treatment reduced the infiltration of CD4+ and CD49+/VLA4 T cells. In addition, treatment of T cells from MS patients with AS101 resulted in apoptosis, while such treatment did not affect T cells from healthy donors. These results suggest that AS101 reduces accumulation of leukocytes in the CNS by inhibiting the activity of the VLA-4 integrin, and provide a rationale for the potential use of Tellurium IV compounds for the treatment of MS.

Recent research has proposed that GIT2 (G protein-coupled receptor kinase interacting protein 2) acts as an integrator of the aging process through regulation of ‘neurometabolic’ integrity. One of the commonly accepted hallmarks of the aging process is thymic involution. At a relatively young age, 12 months old, GIT2−/− mice present a prematurely distorted thymic structure and dysfunction compared to age-matched 12 month-old wild-type control (C57BL/6) mice. Disruption of thymic structure in GIT2−/− (GIT2KO) mice was associated with a significant reduction in the expression of the cortical thymic marker, Troma-I (cytokeratin 8). Double positive (CD4+CD8+) and single positive CD4+ T cells were also markedly reduced in 12 month-old GIT2KO mice compared to age-matched control wild-type mice. Coincident with this premature thymic disruption in GIT2KO mice was the unique generation of a novel cervical ‘organ’, i.e. ‘parathymic lobes’. These novel organs did not exhibit classical peripheral lymph node-like characteristics but expressed high levels of T cell progenitors that were reflexively reduced in GIT2KO thymi. Using signaling pathway analysis of GIT2KO thymus and parathymic lobe transcriptomic data we found that the molecular signaling functions lost in the dysfunctional GIT2KO thymus were selectively reinstated in the novel parathymic lobe – suggestive of a compensatory effect for the premature thymic disruption. Broader inspection of high-dimensionality transcriptomic data from GIT2KO lymph nodes, spleen, thymus and parathymic lobes revealed a systemic alteration of multiple proteins (Dbp, Tef, Per1, Per2, Fbxl3, Ddit4, Sin3a) involved in the multidimensional control of cell cycle clock regulation, cell senescence, cellular metabolism and DNA damage. Altered cell clock regulation across both immune and non-immune tissues therefore may be responsible for the premature ‘aging’ phenotype of GIT2KO mice.