Citations

ABSTRACT Rtt109 is a lysine acetyltransferase that acetylates histone H3 at lysine 56 (H3K56) in fungi. This acetylation event is important for proper DNA replication and repair to occur. Efficient Rtt109 acetyltransferase activity also requires a histone chaperone, vacuolar protein sorting 75 (Vps75), as well as the major chaperone of the H3-H4 dimer, anti-silencing factor 1 (Asf1). Little is known about the role of these proteins in the opportunistic fungal pathogen Pneumocystis carinii . To investigate the functions of Asf1 and Vps75 in Pneumocystis carinii , we cloned and characterized both of these genes. Here, we demonstrate that both genes, P. carinii asf1 ( Pcasf1 ) and Pcvps75 , function in a fashion analogous to their Saccharomyces cerevisiae counterparts. We demonstrate that both P. carinii Asf1 (PcAsf1) and PcVps75 can bind histones. Furthermore, when Pcasf1 is expressed heterologously in S. cerevisiae asf1 Δ cells, PcAsf1 can restore full H3 lysine acetylation. We further demonstrated that the Pcasf1 cDNA expressed in asf1 Δ S. cerevisiae cells can restore growth to wild-type levels in the presence of genotoxic agents that block DNA replication. Lastly, we observed that purified PcAsf1 and PcVps75 proteins enhance the ability of PcRtt109 to acetylate histone H3-H4 tetramers. Together, our results indicate that the functions of the Rtt109-Asf1-Vps75 complex in the acetylation of histone H3 lysine 56 and in DNA damage response are present in P. carinii DNA and cell cycle progression.

Abstract Psychological stress can lead to asthma exacerbations in some patients. It is our hypothesis that the stress effect can occur through an enhancement of allergic inflammatory response. To investigate this possibility, airway antigen challenge was evaluated in 20 college students with mild asthma during both a low-stress phase (midsemester or two weeks postfinal examination) and a stress phase (final examination week). Subjects completed questionnaires to assess psychological state and underwent inhaled antigen challenge. Sputum samples were collected before challenge, and six and 24 hours and seven days postchallenge. Leukocytes were counted and eosinophil-derived neurotoxin (EDN) was measured in sputum supernates. Sputum cells were cultured and stimulated ex vivo with phytohemagglutinin (10 μ g/ml), and culture supernates were assayed for interleukin-5 (IL-5) and interferon- γ by enzyme-linked immunosorbent assay. Sputum eosinophils and EDN levels significantly increased at six and 24 hours postchallenge and were enhanced during the stress phase (p < 0.01). IL-5 generation by sputum cells was also increased at 24 hours during stress and correlated with airway eosinophils (rs = 0.65, p < 0.05). Students' anxiety and depression scores were significantly higher during the examination period. Our findings suggest that stress associated with final examinations can act as a cofactor to increase eosinophilic airway inflammation to antigen challenge and thus may enhance asthma severity.

BackgroundThe purpose of this study was to report the treatment outcomes of patients with advanced oropharyngeal cancer treated with transoral laser microsurgery (TLM) followed by radiation therapy (RT) at Mayo Clinic in Arizona.MethodsA retrospective study of 80 patients treated from January 1, 2000 to November 7, 2011 was performed. All patients had stage III/IV oropharyngeal tumors and underwent TLM with neck dissection. Adjuvant RT was then given. Thirty‐seven patients received concurrent adjuvant chemotherapy. The primary outcome was locoregional control.ResultsMedian follow‐up was 47.3 months (range, 9.7–139.2 months). The 3‐year locoregional control, recurrence‐free survival, and overall survival rates were 98.6% (95% confidence interval [CI], 91% to 100%), 91.1% (95% CI, 81% to 96%), and 93.7% (95% CI, 84% to 98%), respectively. There were a total of 5 treatment failures, 1 regional and 4 distant. Twenty‐six patients underwent neck only RT with exclusion of the primary site.ConclusionTLM followed by RT for advanced oropharyngeal cancer results in excellent locoregional control rates. © 2013 Wiley Periodicals, Inc. Head Neck 36: 220–225, 2014

ObjectiveFree fatty acids (FFAs) are increased in visceral fat and contribute to insulin resistance through multiple mechanisms, including c‐Jun N‐terminal kinase (JNK) activation and expression of TNFα. Given that insulin‐like growth factor‐1 (IGF‐1)‐mediated proliferation is impaired in omental compared to subcutaneous (SC) preadipocytes, we investigated IGF‐I anti‐inflammatory action in preadipocytes from SC and omental adipose tissue.Design and MethodsPreadipocytes isolated from abdominal SC and omental fat of obese subjects were studied in primary culture. Cells were exposed to FFAs with or without IGF‐I pretreatment followed by analysis of cytokine expression and JNK phosphorylation. Lentivirus infection was used to express a constitutively active AKT (myr‐AKT) in omental preadipocytes.ResultsFFAs increased the expression of tumor necrosis factor (TNF)α, interleukin (IL)‐6, and monocyte chemotactic protein (MCP)‐1 in SC and omental preadipocytes. IGF‐I pretreatment reduced FFA‐induced JNK1 phosphorylation and TNFα expression in SC but not omental preadipocytes. Treatment with the JNK1/2 inhibitor SP600125 reduced FFA‐induced expression of TNFα. FFAs and MALP‐2, a specific TLR2/6 ligand, but not specific ligands for TLR4 and TLR1/2, increased JNK1 phosphorylation. IGF‐I completely inhibited MALP‐2‐stimulated phosphorylation of JNK1. Expression of myr‐AKT in omental preadipocytes inhibited FFA‐stimulated JNK1 phosphorylation.ConclusionsIGF‐I attenuated FFA‐induced JNK1 phosphorylation and TNFα expression through activation of AKT in human subcutaneous but not omental preadipocytes.

Aberrant connectivity is implicated in many neurological and psychiatric disorders, including Alzheimer’s disease and schizophrenia. However, other than a few disease-associated candidate genes, we know little about the degree to which genetics play a role in the brain networks; we know even less about specific genes that influence brain connections. Twin and family-based studies can generate estimates of overall genetic influences on a trait, but genome-wide association scans (GWASs) can screen the genome for specific variants influencing the brain or risk for disease. To identify the heritability of various brain connections, we scanned healthy young adult twins with high-field, high-angular resolution diffusion MRI. We adapted GWASs to screen the brain’s connectivity pattern, allowing us to discover genetic variants that affect the human brain’s wiring. The association of connectivity with the SPON1 variant at rs2618516 on chromosome 11 (11p15.2) reached connectome-wide, genome-wide significance after stringent statistical corrections were enforced, and it was replicated in an independent subsample. rs2618516 was shown to affect brain structure in an elderly population with varying degrees of dementia. Older people who carried the connectivity variant had significantly milder clinical dementia scores and lower risk of Alzheimer’s disease. As a posthoc analysis, we conducted GWASs on several organizational and topological network measures derived from the matrices to discover variants in and around genes associated with autism ( MACROD2 ), development ( NEDD4 ), and mental retardation ( UBE2A ) significantly associated with connectivity. Connectome-wide, genome-wide screening offers substantial promise to discover genes affecting brain connectivity and risk for brain diseases.

ObjectiveChildren with childhood‐onset rheumatoid arthritis (RA) include those with rheumatoid factor or anti–citrullinated protein antibody–positive juvenile idiopathic arthritis. To test the hypothesis that adult‐onset RA–associated variants are also associated with childhood‐onset RA, we investigated RA‐associated variants at 5 loci in a cohort of patients with childhood‐onset RA. We also assessed the cumulative association of these variants in susceptibility to childhood‐onset RA using a weighted genetic risk score (wGRS).MethodsA total of 155 children with childhood‐onset RA and 684 healthy controls were genotyped for 5 variants in the PTPN22, TRAF1/C5, STAT4, and TNFAIP3 loci. High‐resolution HLA–DRB1 genotypes were available for 149 cases and 373 controls. We tested each locus for association with childhood‐onset RA via logistic regression. We also computed a wGRS for each subject, with weights based on the natural log of the published odds ratios (ORs) for the alleles investigated, and used logistic regression to test the wGRS for association with childhood‐onset RA.ResultsChildhood‐onset RA was associated with TNFAIP3 rs10499194 (OR 0.60 [95% confidence interval 0.44–0.83]), PTPN22 rs2476601 (OR 1.61 [95% confidence interval 1.11–2.31]), and STAT4 rs7574865 (OR 1.41 [95% confidence interval 1.06–1.87]) variants. The wGRS was significantly different between cases and controls (P < 2 × 10−16). Individuals in the third to fifth quintiles of wGRS had a significantly increased disease risk compared to baseline (individuals in the first quintile). Higher wGRS was associated with increased risk of childhood‐onset RA, especially among males.ConclusionThe magnitude and direction of the association between TNFAIP3, STAT4, and PTPN22 variants and childhood‐onset RA are similar to those observed in RA, suggesting that adult‐onset RA and childhood‐onset RA share common genetic risk factors. Using a wGRS, we have demonstrated the cumulative association of RA‐associated variants with susceptibility to childhood‐onset RA.

Pazopanib and paclitaxel produce cytotoxic synergy in thyroid cancer models through inhibition of aurora kinase A.

ABSTRACT Many postmenopausal women treated with teriparatide for osteoporosis have previously received antiresorptive therapy. In women treated with alendronate (ALN) or raloxifene (RLX), adding versus switching to teriparatide produced different responses in areal bone mineral density (aBMD) and biochemistry; the effects of these approaches on volumetric BMD (vBMD) and bone strength are unknown. In this study, postmenopausal women with osteoporosis receiving ALN 70 mg/week (n = 91) or RLX 60 mg/day (n = 77) for ≥18 months were randomly assigned to add or switch to teriparatide 20 µg/day. Quantitative computed tomography scans were performed at baseline, 6 months, and 18 months to assess changes in vBMD; strength was estimated by nonlinear finite element analysis. A statistical plan specifying analyses was approved before assessments were completed. At the spine, median vBMD and strength increased from baseline in all groups (13.2% to 17.5%, p &lt; 0.01); there were no significant differences between the Add and Switch groups. In the RLX stratum, hip vBMD and strength increased at 6 and 18 months in the Add group but only at 18 months in the Switch group (Strength, Month 18: 2.7% Add group, p &lt; 0.01 and 3.4% Switch group, p &lt; 0.05). In the ALN stratum, hip vBMD increased in the Add but not in the Switch group (0.9% versus –0.5% at 6 months and 2.2% versus 0.0% at 18 months, both p ≤ 0.004 group difference). At 18 months, hip strength increased in the Add group (2.7%, p &lt; 0.01) but not in the Switch group (0%); however, the difference between groups was not significant (p = 0.076). Adding or switching to teriparatide conferred similar benefits on spine strength in postmenopausal women with osteoporosis pretreated with ALN or RLX. Increases in hip strength were more variable. In RLX-treated women, strength increased more quickly in the Add group; in ALN-treated women, a significant increase in strength compared with baseline was seen only in the Add group.