Project description:This series examines gene expression in the anterior midgut at several time points (2, 4, 8, & 16 h) after topical application of juvenile hormone III (JHIII) or acetone (control) to adult beetles of both sexes. Keywords = North American pine engraver beetle Keywords = anterior midgut Keywords = juvenile hormone Keywords = pheromone biosynthesis Keywords = Coleoptera Keywords = Scolytidae Keywords: other
Project description:Ips spp. bark beetles use ipsdienol, ipsenol, ipsdienone and ipsenone as aggregation pheromone components and pheromone precursors. For Ips pini, the short-chain oxidoreductase ipsdienol dehydrogenase (IDOLDH) converts (-)-ipsdienol to ipsdienone, and thus likely plays a role in determining pheromone composition. In order to further understand the role of IDOLDH in pheromone biosynthesis, we compared IDOLDH to its nearest functionally characterized ortholog with a solved structure: human L-3-hydroxyacyl-CoA dehydrogenase type II/ amyloid-β binding alcohol dehydrogenase (hHADH II/ABAD), and conducted functional assays of recombinant IDOLDH to determine substrate and product ranges and structural characteristics. Although IDOLDH and hHADH II/ABAD had only 35% sequence identity, their predicted tertiary structures had high identity. We found IDOLDH is a functional homo-tetramer. In addition to oxidizing (-)-ipsdienol, IDOLDH readily converted racemic ipsenol to ipsenone, and stereo-specifically reduced both ketones to their corresponding (-)-alcohols. The (+)-enantiomers were never observed as products. Assays with various substrate analogs showed IDOLDH had high substrate specificity for (-)-ipsdienol, ipsenol, ipsenone and ipsdienone, supporting that IDOLDH functions as a pheromone-biosynthetic enzyme. These results suggest that different IDOLDH orthologs and or activity levels contribute to differences in Ips spp. pheromone composition.
Project description:Calorie restriction (CR) is a dietary regimen that supports healthy aging. In this study we investigated the systemic and liver-specific responses caused by a diet switch to a medium-fat (MF) diet in 24-month-old life-long, CR-exposed mice. This study aimed to increase the knowledge base on dietary alterations of gerontological relevance. Nine-week-old C57BL/6J mice were exposed either to a control, CR or MF diet. At the age of 24 months, a subset of mice of the CR group was transferred to ad libitum MF feeding (CR-MF).The mice were sacrificed at the age of 28 months, then biochemical and molecular analyses were performed. Our results showed that, despite the long-term exposure to the CR regimen, mice in the CR-MF group displayed hyperphagia, rapid weight gain, and hepatic steatosis. However, no hepatic fibrosis/injury or alteration in CR-improved survival was observed in the diet switch group. The liver transcriptomic profile of CR-MF mice largely shifted to a profile similar to the MF-fed animals but leaving ~22% of the 1578 differentially regulated genes between the CR and MF diet groups comparable with the expression of the life-long CR group. Therefore, although the diet switch was performed at an old age, the CR-MF-exposed mice showed plasticity in coping with the challenge of a MF diet without developing severe liver pathologies.
Project description:Calorie restriction (CR) has been shown to extend life- and health-span in model species. For most humans, a life-long CR diet is too arduous to adhere to. The aim of this study was to explore whether weekly intermittent CR can 1) provide long-term beneficial effects and 2) counteract diet-induced obesity in male aging mice. In this study, we have exposed C57Bl/6J mice for 24 months to an intermittent (INT) diet, alternating weekly between CR of a control diet and ad libitum moderate-fat (MF) feeding. This weekly intermittent CR significantly counteracted the adverse effects of the MF diet on mortality, body weight and liver health markers in male 24-month-old mice. Hepatic gene expression profiles of INT-exposed animals appeared much more comparable to CR than to MF-exposed mice. At 12 months of age, a subgroup of MF-exposed mice was transferred to the INT diet. Gene expression profiles in the liver of the 24-month-old diet switch mice were highly similar to the INT-exposed mice. However, a small subset of genes was consistently changed by the MF diet during the first phase of life. Weekly intermittent CR largely, but not completely, reversed adverse effects caused by a MF diet.
Project description:We analyzed 14 patients with Myelofibrosis (MF) to determine the miRNA profile of patients not responding to current MF treatment. We used Affymetrix miRNA-3 array to profile the differentially expressed miRNA in bone-marrow between patients with MF that respond to current MF treatment and the patients with MF that do not respond to current MF treatment.
Project description:Epigenetic changes deregulate gene expression to drive oncogenesis. The reversible nature of these changes enables therapeutic targeting, as in cutaneous T-cell lymphoma (MF/SS), Histone deacetylase inhibitors (HDACi), which alter epigenetic modifications, are effective in ~30% of MF/SS patients. However, there are no markers that predict MF/SS progression or therapy resistance. We hypothesized that epigenetic alterations drive MF/SS progression and promote HDACi drug resistance. Therefore, we profiled the epigenomes and transcriptomes of malignant T cell purified from skin biopsies and peripheral blood from MF/SS patients (N=21) before and after treatment with HDACi, as well as in vitro HDACi-treated CD4+ T cells from healthy donors. Here we report for the first time the epigenome-wide map of acetylation changes in MF/SS patients treated with HDACi, and define the significant differences in regulatory element activity and corresponding transcriptional changes in HDACi-sensitive versus resistant tumors. Our studies identified genes not previously associated with MF/SS, nor with disease progression or HDACi resistance, and were enriched in pathways that regulate apoptosis (BIRC5), cell cycle (RRM2), and chromosome cohesion (CENPH). We also identified a striking number of genes whose products are involved in cell adhesion and migration, including CCR6, LAIR2, VCAM1, and EPCAM. The mRNA of LAIR2, which encodes a receptor protein secreted by activated T cells that binds collagen and prevents binding of the inhibitory receptor LAIR1, was significantly upregulated in MF/SS tumors that were resistant to HDACi therapy and manifested in both skin and peripheral blood. We also detected elevated levels of LAIR2 protein in the plasma of MF/SS patients with progressive disease. Taken together, these studies defined the first epigenome-wide acetylation landscape of HDACi responsive and resistant MF/SS tumors, identified significantly altered patterns of epigenetic regulation and corresponding gene expression in HDACi resistant MF/SS tumors, and connected them to novel pathways of disease progression, particularly in cell adhesion and migration. These findings may represent novel predictive markers for MF/SS progression that are also targets for future therapeutic development.