In vivo, negative autoregulation of the strong major immediate early promoter (MEEP) of human cytomegalovirus requires the viral immediate early 2 protein (IE2) and a cis element located from position -13 through position -1 relative to the transcription start site. We have established an in vitro transcription system that reproduces the specificity of EE2-mediated negative autoregulation. [12][13][14].The precise mechanism of IE2-mediated repression is not yet understood. We have expressed the carboxyl-terminal 290 amino acids of IE2 as a bacterial fusion protein and have established an in vitro system that reproduces the specificities of repression as defined by in vivo studies. In addition, using conditions functionally tested by the in vitro transcription system, we have performed gel mobility-shift assays that provide evidence that the carboxyl-terminal 290 amino acids of IE2 are sufficient to mediate direct and site-dependent binding to the MIEP. Our data suggest that the mechanism for IE2-mediated repression of the MIEP involves direct interaction between the wild-type IE2 and the cis-acting repressor element.MATERIALS AND METHODS Recombinant Plasmids. To produce the pKS760E (wildtype promoter) and pKSd1REE (mutant promoter) templates used in run-off transcription assays, the 1-kilobase (kb) EcoRI fragment from pCAT760 (2) or pCAT760d1RE (12), respectively, was subcloned into the EcoRI site of the pBluescript II phagemid vector KS+ (Stratagene).Constructs used to produce recombinant proteins were based on the plasmid vector pMAL-c (New England Biolabs), which expresses the cloned sequence of interest fused to the Escherichia coli maltose binding protein by induction with isopropyl P-D-thiogalactoside (IPTG). Plasmid pMALcXS has a 1.4-kb Xho I (filled-in with Klenow fragment)/Sal I fragment from exon 5 of IE2 inserted into the Stu I/Sal I cloning sites of pMAL-c. Plasmid pMALcHL was constructed in the same manner as pMALcXS except that the 1.4-kb insert was isolated from the mutant plasmid HL446,452 (K. C. Yeung, M. Leatham, and M.F.S., unpublished work).Purification of Recombinant Proteins. The protein fusion and purification system was obtained from New England Biolabs and used according to manufacturer instructions with the following modifications: (i) batch purification was performed and (ii) the elution buffer was 10 mM Hepes, pH 8.0/10%o (vol/vol) glycerol/0.1 mM EDTA/30 mM maltose.Preparation of HeLa Cell Nuclear Extracts. Nuclear extracts were prepared by a modification of the method of Lee and Green (15). Extracts were diluted, rather than dialyzed, with an equal volume of buffer D-at the final step (16). In some experiments, the HeLa cell nuclear extracts were obtained from Promega.In

Transgenic (Tg) mouse models of Alzheimer’s disease (AD) have been extensively used to study the pathophysiology of this dementia and to test the efficacy of drugs to treat AD. The 5XFAD Tg mouse, which contains two presenilin-1 and three amyloid precursor protein (APP) mutations, was designed to rapidly recapitulate a portion of the pathologic alterations present in human AD. APP and its proteolytic peptides, as well as apolipoprotein E and endogenous mouse tau, were investigated in the 5XFAD mice at 3 months, 6 months, and 9 months. AD and nondemented subjects were used as a frame of reference. APP, amyloid-beta (Aβ) peptides, APP C-terminal fragments (CT99, CT83, AICD), β-site APP-cleaving enzyme, and APLP1 substantially increased with age in the brains of 5XFAD mice. Endogenous mouse tau did not show age-related differences. The rapid synthesis of Aβ and its impact on neuronal loss and neuroinflammation make the 5XFAD mice a desirable paradigm to model AD.

We have developed a transgenic mouse line, NJ.1638, which expresses high levels of IL-5 from T cells, with profound hematological consequences. Eosinophils comprise more than 60% of circulating white blood cells in these animals, with the total peripheral white blood cell counts increasing more than 40-fold relative to wild-type littermates. This extraordinary proliferative capacity is sustained by expanded sites of extramedullary hematopoiesis and is accompanied by multifocal, ectopic bone formation in the spleen. Histology of the splenic nodules revealed the presence of osteoid matrices and osteocytes trapped within mineralized trabecular plates. In addition, polarized light microscopy of calcified tissue sections revealed both woven bone and areas of organized lamellar bone. Morphometric assessments demonstrated that both the growth and mineralization of splenic bone occurred at rates nearly an order of magnitude higher than in skeletal bone. Skeletal bone metabolic parameters were also perturbed. We also observed heterotopic ossification of the spleen and perturbation of skeletal bone homeostasis following adoptive engraftment of transgenic marrow to wild-type recipients. These data suggest that IL-5 overexpression mediates bone formation through the mobilization of marrowderived osteogenic progenitors and/or the inhibition of recruited osteoclasts.

Introduction To date there is no cure for Alzheimer's disease (AD). After amyloid beta immunotherapies have failed to meet primary endpoints of slowing cognitive decline in AD subjects, the inhibition of the beta-secretase BACE1 appears as a promising therapeutic approach. Pre-clinical data obtained in APP23 mice suggested that the anti-cancer drug thalidomide decreases brainBACE1 and Aβ levels. This prompted us to develop an NIH-supported Phase IIa clinical trial to test the potential of thalidomide for AD. We hypothesized that thalidomide can decrease or stabilize brain amyloid deposits, which would result in slower cognitive decline in drug- versus placebo-treated subjects. Methods This was a 24-week, randomized, double-blind, placebo-controlled, parallel group study with escalating dose regimen of thalidomide with a target dose of 400mg daily in patients with mild to moderate AD. The primary outcome measures were tolerability and cognitive performance assessed by a battery of tests. Results A total of 185 subjects have been pre-screened, out of which25 were randomized. Mean age of the sample at baseline was 73.64 (±7.20) years; mean education was 14.24 (±2.3) years; mean MMSE score was 21.00 (±5.32); and mean GDS score was 2.76 (±2.28).Among the 25 participants, 14 (56%) terminated early due to adverse events, dramatically decreasing the power of the study. In addition, those who completed the study (44%) never reached the estimated therapeutic dose of 400 mg/day thalidomide because of reported adverse events. The cognitive data showed no difference between the treated and placebo groups at the end of the trial. Conclusion This study demonstrates AD patients have poor tolerability for thalidomide, and are unable to reach a therapeutic dose felt to be sufficient to have effects on BACE1. Because of poor tolerability, this study failed to demonstrate a beneficial effect on cognition.

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