The rockefeller university

Translocations or mutations of FUS, EWSR1, and TAF15 (FET) result in distinct genetic diseases. N-terminal translocations of any FET protein to a series of transcription factors yields chimeric proteins that contribute to sarcomagenesis, whereas mutations in the conserved COOH-terminal domain of wild-type FUS were recently shown to cause familial amyotrophic lateral sclerosis. We thus investigated whether the loss of one FUS allele by translocation in liposarcoma may be followed by mutations in either the remaining FUS allele or the paralogous EWSR1. Furthermore, we investigated the strength of the FET promoters and their contributions to sarcomagenesis given the proteins' frequent involvement in oncogenic translocations. We sequenced the respective genomic regions of both FUS and EWSR1 in 96 liposarcoma samples. Additionally, we determined FET transcript and protein levels in several liposarcoma cell lines. We did not observe sequence variations in either FUS or EWSR1. However, protein copy numbers reached an impressive 0.9 and 5.5 Mio of FUS and EWSR1 per tumor cell, respectively. Compared with adipose-derived stem cells, FUS and EWSR1 protein expression levels were elevated on average 28.6-fold and 7.3-fold, respectively. TAF15 mRNA levels were elevated on average 3.9-fold, although with a larger variation between samples. Interestingly, elevated TAF15 mRNA levels did not translate to strongly elevated protein levels, consistent with its infrequent occurrence as translocation partner in tumors. These results suggest that the powerful promoters of FET genes are predominantly responsible for the oncogenic effect of transcription factor translocations in sarcomas. (C) 2011 Wiley-Liss, Inc.

Nucleosome-depleted regions (NDRs) are ubiquitous on eukaryotic promoters. The formation of many NDRs cannot be readily explained by previously proposed mechanisms. Here, we carry out a focused study on a physiologically important NDR in the yeast CLN2 promoter (CLN2pr). We show that this NDR does not result from intrinsically unfavorable histone-DNA interaction. Instead, we identified eight conserved factor binding sites, including that of Reb1, Mcm1, and Rsc3, that cause the local nucleosome depletion. These nucleosome-depleting factors (NDFs) work redundantly, and simultaneously mutating all their binding sites eliminates CLN2pr NDR. The loss of the NDR induces unreliable "on/off" expression in individual cell cycles, but in the presence of the NDR, NDFs have little direct effect on transcription. We present bioinformatic evidence that the formation of many NDRs across the genome involves multiple NDFs. Our findings also provide significant insight into the composition and spatial organization of functional promoters.

Hepatitis C virus (HCV) is associated with the B-cell lymphoproliferative disorders mixed cryoglobulinemia (MC) and non-Hodgkin lymphoma. We have previously reported that HCV+MC+ patients have clonal expansions of hypermutated, rheumatoid factor-bearing marginal zone-like IgM(+)CD27(+) peripheral B cells using the V(H)1-69 gene. Here we coupled transcriptional profiling with immunophenotypic and functional studies to ascertain these cells' role in MC pathogenesis. Despite their fundamental role in MC disease, these B cells have overall transcriptional features of anergy and apoptosis instead of neoplastic transformation. Highly up-regulated genes include SOX5, CD11C, galectin-1, and FGR, similar to a previously described FCRL4(+) memory B-cell subset and to an "exhausted," anergic CD21(low) memory B-cell subset in HIV+ patients. Moreover, HCV+MC+ patients' clonal peripheral B cells are enriched with CD21(low), CD11c(+), FCRL4(high), IL-4R(low) memory B cells. In contrast to the functional, rheumatoid factor-secreting CD27(+)CD21(high) subset, the CD27(+) CD21(low) subpopulation exhibits decreased cal-cium mobilization and does not efficiently differentiate into rheumatoid factorsecreting plasmablasts, suggesting that a large proportion of HCV+MC+ patients' clonally expanded peripheral B cells is prone to anergy and/or apoptosis. Downregulation of multiple activation pathways may represent a homeostatic mechanism attenuating otherwise uncontrolled stimulation of circulating HCV-containing immune complexes. This study was registered at www. clinicaltrials. gov as #NCT00435201. (Blood. 2011;117(20):5425-5437)

Reduced brain metabolism is an invariant feature of Alzheimer Disease (AD) that is highly correlated to the decline in brain functions. Decreased activities of key tricarboxylic acid cycle (TCA) cycle enzymes may underlie this abnormality and are highly correlated to the clinical state of the patient. The activity of the alpha-ketoglutarate dehydrogenase complex (KGDHC), an arguably rate-limiting enzyme of the TCA cycle, declines with AD, but the mechanism of inactivation and whether it can be reversed remains unknown. KGDHC consists of multiple copies of three subunits. KGDHC is sensitive to oxidative stress, which is pervasive in AD brain. The present studies tested the mechanism for the peroxynitrite-induced inactivation and subsequent reactivation of purified and cellular KGDHC. Peroxynitrite inhibited purified KGDHC activity in a dose-dependent manner and reduced subunit immunoreactivity and increased nitrotyrosine immunoreactivity. Nano-LC-MS/MS showed that the inactivation was related to nitration of specific tyrosine residues in the three subunits. GSH diminished the nitrotyrosine immunoreactivity of peroxynitrite-treated KGDHC, restored the activity and the immunoreactivity for KGDHC. Nano-LC-MS/MS showed this was related to de-nitration of specific tyrosine residues, suggesting KGDHC may have a denitrase activity. Treatment of N2a cells with peroxynitrite for 5 min followed by recovery of cells for 24 h reduced KGDHC activity and increased nitrotyrosine immunoreactivity. Increasing cellular GSH in peroxynitrite-treated cells rescued KGDHC activity to the control level. The results suggest that restoring KGDHC activity is possible and may be a useful therapeutic approach in neurodegenerative diseases.

The economy of space and materials and the continuously increasing demand for advanced functionalities for diverse technologies requires the development of new synthetic methods. Many nanomaterials have enhanced photophysical and photochemical properties in solutions and/or on surfaces, while others have enhanced chemical properties, compared to the atomic, molecular, or bulk phases. Nanomaterials have a wide range of applications in catalysis, sensors, photonic devices, drug delivery, and as therapeutics for treatment of a variety of diseases. Inorganic nanoparticles are widely studied, but the formation of organic nanomaterials via supramolecular chemistry is more recent, and porphyrinoids are at the forefront of this research because of their optical, chemical, and structural properties. The formation of nanoscaled materials via self-assembly and/or self-organization of molecular subunits is an attractive approach because of reduced energy requirements, simpler molecular subunits, and the material can be adaptive to environmental changes. The presence of biocompatible groups such as peptides, carbohydrates, polyglycols and mixtures of these on the periphery of the porphyrin macrocycle may make nanoparticles suitable for therapeutics. This perspective focuses on responsive, non-crystalline porphyrinoid nanomaterials that are less than about 100 nm in all dimensions and used for catalytic or therapeutic applications.

Centrioles are self-reproducing organelles that form the core structure of centrosomes or microtubule-organizing centers (MTOCs). However, whether duplication and MTOC organization reflect innate activities of centrioles or activities acquired conditionally is unclear. In this paper, we show that newly formed full-length centrioles had no inherent capacity to duplicate or to organize pericentriolar material (PCM) but acquired both after mitosis through a Plk1-dependent modification that occurred in early mitosis. Modified centrioles initiated PCM recruitment in G1 and segregated equally in mitosis through association with spindle poles. Conversely, unmodified centrioles segregated randomly unless passively tethered to modified centrioles. Strikingly, duplication occurred only in centrioles that were both modified and disengaged, whereas unmodified centrioles, engaged or not, were "infertile," indicating that engagement specifically blocks modified centrioles from reduplication. These two requirements, centriole modification and disengagement, fully exclude unlimited duplication in one cell cycle. We thus uncovered a Plk1-dependent mechanism whereby duplication and segregation are coupled to maintain centriole homeostasis.

Atopic dermatitis and psoriasis are 2 of the most common inflammatory skin diseases. They are similar in that they are complex inherited diseases involving genes that encode immune components and structural proteins that regulate differentiation of epidermal cells. Each disease is characterized by proliferation of epidermal keratinocytes and abnormal cornification or terminal differentiation in the epidermis; skin lesions contain immune infiltrates of T cells, dendritic cells, and other types of leukocytes. We review similarities between the diseases and differences in epidermal barrier defects and immune cells. We also propose mechanisms of pathogenesis based on differences in the balance of immune cell subsets that could cause the phenotypes that distinguish these diseases. The first part of this 2-part review focuses on the clinical and pathologic features of the diseases; the second part discusses differences in immune cell subsets between atopic dermatitis and psoriasis and recent therapeutic strategies. (J Allergy Clin Immunol 2011;127:1110-8.)

Heightened states of generalized CNS arousal are proposed here to facilitate sexual arousal in both males and females. Genetic, pharmacologic and biophysical mechanisms by which this happens are reviewed. Moreover, stimulation of the genital epithelia, as triggers of sex behavior, is hypothesized to lead to a greater generalized arousal in a manner that intensifies sexual motivation. Finally, launched from histochemical studies intended to characterize cells in the genital epithelium, a surprising idea is proposed that links density of innervation with the efficiency of wound healing and with the capacity of that epithelium to stimulate generalized CNS arousal. Thus, bidirectional arousal-related mechanisms that foster sexual behaviors are envisioned as follows: from specific to generalized (as with genital stimulation) and from generalized to specific. (C) 2010 Elsevier Inc. All rights reserved.