No abstract

Cerebral cortical cholinergic activity is decreased to a similar level in Parkinson disease (PD), parkinsonian syndromes of multiple system atrophy (MSA-P), and progressive supranuclear palsy (PSP) as compared to normal controls. Subcortical cholinergic activity is significantly more decreased in MSA-P and PSP than in PD. The more substantial decrease reflects greater impairment in the pontine cholinergic group, which is important in motor activity, particularly gait. These differences may account for the greater gait disturbances in the early stages of MSA-P and PSP than in PD.

Heat shock proteins (HSP) are essential for intracellular protein folding during stress and protect cells from denaturation and aggregation cascades that can lead to cell death. HSP genes are regulated at the transcriptional level by heat shock transcription factor 1 (HSF1) that is activated by stress and binds to heat shock elements in HSP genes. The activation of HSF1 during heat shock involves conversion from an inert monomer to a DNA binding trimer through a series of intramolecular folding rearrangements. However, the trigger for HSF1 at the molecular level is unclear and hypotheses for this process include reversal of feedback inhibition of HSF1 by molecular chaperones and heat-induced binding to large non-coding RNAs. Heat shock also causes a profound modulation in cell signaling pathways that lead to protein kinase activation and phosphorylation of HSF1 at a number of regulatory serine residues. HSP genes themselves exist in an accessible chromatin conformation already bound to RNA polymerase II. The RNA polymerase II is paused on HSP promoters after transcribing a short RNA sequence proximal to the promoter. Activation by heat shock involves HSF1 binding to the promoter and release of the paused RNA polymerase II followed by further rounds of transcriptional initiation and elongation. HSF1 is thus involved in both initiation and elongation of HSP RNA transcripts. Recent studies indicate important roles for histone modifications on HSP genes during heat shock. Histone modification occurs rapidly after stress and may be involved in promoting nucleosome remodeling on HSP promoters and in the open reading frames of HSP genes. Understanding these processes may be key to evaluating mechanisms of deregulated HSP expression that plays a key role in neurodegeneration and cancer.

Self-incompatibility (SI) in the Solanaceae, Rosaceae and Scrophulariaceae is controlled by the polymorphic S locus, which contains two separate genes encoding pollen and pistil determinants in SI interactions. The S-RNase gene encodes the pistil determinant, whereas the pollen determinant gene, named the pollen S gene, has not yet been identified. Here, we set out to construct an integrated genetic and physical map of the S locus of Petunia inflata and identify any additional genes located at this locus. We first conducted chromosome walking at the S2 locus using BAC clones that contained either S2-RNase or one of the nine markers tightly linked to the S locus. Ten separate contigs were constructed, which collectively spanned 4.4 Mb. To identify additional genes located at the S2 locus, a 328-kb region (part of an 881-kb BAC contig) containing S2-RNase was completely sequenced. Approximately 76% of the region contained repetitive sequences, including transposon-like sequences. Other than S2-RNase, an F-box gene, named PiSLF2 (S2-allele of P. inflata S-locus F-box gene), was the only predicted gene whose deduced amino acid sequence was similar to the sequences of known proteins in the database. Two different cDNA selection methods were used to identify additional genes in the 881-kb contig; 11 groups of cDNA clones were identified in addition to those for S2-RNase and PiSLF2. RT-PCR analysis of expression profiles and PCR analysis of BAC clones and genomic DNA confirmed that seven of these 11 newly identified genes were located in the 881-kb contig.

Recent findings established that primary targets of HIV/SIV are lymphoid cells within the gastrointestinal (GI) tract. Focus has therefore shifted to T-cells expressing α4β7 integrin which facilitates trafficking to the GI tract via binding to MAdCAM-1. Approaches to better understand the role of α4β7+ T-cells in HIV/SIV pathogenesis include their depletion or blockade of their synthesis, binding and/or homing capabilities in vivo. Such studies can ideally be conducted in rhesus macaques (RM), the non-human primate model of AIDS. Characterization of α4β7 expression on cell lineages in RM blood and GI tissues reveal low densities of expression by NK cells, B-cells, naïve and TEM (effector memory) T-cells. High densities were observed on TCM (central memory) T-cells. Intravenous administration of a single 50 mg/kg dose of recombinant rhesus α4β7 antibody resulted in significant initial decline of α4β7+ lymphocytes and sustained coating of the α4β7 receptor in both the periphery and GI tissues.

Background-Higher levels of N-terminal prohormone brain-type natriuretic peptide (NT-proBNP) predict cardiovascular disease (CVD) in several disease states, but few data are available in patients with chronic kidney disease or in blacks. Methods and Results-The African American Study of Kidney Disease and Hypertension trial enrolled hypertensive blacks with a glomerular filtration rate of 20 to 65 mL · min Ϫ1 · 1.73 m Ϫ2 and no other identified cause of kidney disease. NT-proBNP was measured with a sandwich chemiluminescence immunoassay (coefficient of variation 2.9%) in 994 African American Study of Kidney Disease and Hypertension participants. NT-proBNP was categorized as undetectable, low, moderate, or high. Proteinuria was defined as 24-hour urinary protein-creatinine ratio Ͼ0.22. A total of 134 first CVD events (CVD death or hospitalization for coronary artery disease, heart failure, or stroke) occurred over a median of 4.3 years. Participants with high NT-proBNP were much more likely to have a CVD event than participants with undetectable NT-proBNP after adjustment (relative hazard 4.0 [95% confidence interval [CI] 2.1 to 7.6]). A doubling of NT-proBNP was associated with a relative hazard of 1.3 (95% CI 1.0 to 1.6) for coronary artery disease, 1.7 (95% CI 1.4 to 2.2) for heart failure, 1.1 (95% CI 0.9 to 1.4) for stroke, and 1.8 (95% CI 1.4 to 2.4) for CVD death. The association of NT-proBNP with CVD events was significantly stronger (P interaction ϭ0.05) in participants with than in those without proteinuria. Higher NT-proBNP was not associated with renal disease progression. Conclusions-These results suggest that elevated NT-proBNP levels are associated with higher CVD risk among blacks with hypertensive kidney disease. This association may be stronger in individuals with significant proteinuria.

NRADD (neurotrophin receptor alike death domain protein) is a novel protein with transmembrane and cytoplasmic regions highly homologous to death receptors, particularly p75 NTR . However, the short N-terminal domain is unique. Expression of NRADD induced apoptosis in a number of cell lines. The apoptotic mechanism involved the activation of caspase-8 and execution of apoptosis without requiring mitochondrial components. The activation of this death receptor-like mechanism required the N-terminal domain, which is Nglycosylated and needed for subcellular targeting. Deletion of the N-terminal domain produced a dominant-negative form of NRADD that protected neurons and Schwann cells from a variety of endoplasmic reticulum (ER) stressors. NRADD may therefore be a necessary component for generating an ERinduced proapoptotic signal.

Most methods for assessment of chromatin structure involve chemical or nuclease damage to DNA followed by analysis of distribution and susceptibility of cutting sites. The agents used generally do not permeate cells, making nuclear isolation mandatory. In vivo mapping strategies might allow detection of labile constituents and/or structures that are lost when chromatin is swollen in isolated nuclei at low ionic strengths. DNase I has been the most widely used enzyme to detect chromatin sites where DNA is active in transcription, replication or recombination. We have introduced the bovine DNase I gene into yeast under control of a galactose-responsive promoter. Expression of the nuclease leads to DNA degradation and cell death. Shorter exposure to the active enzyme allows mapping of chromatin structure in whole cells without isolation of nuclei. The validity and efficacy of the strategy are demonstrated by footprinting a labile repressor bound to its operator. Investigation of the inter-nucleosome linker regions in several types of repressed domains has revealed different degrees of protection in cells, relative to isolated nuclei.