| 1. |
- Neely, G Gregory, et al.
(författare)
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A Genome-wide Drosophila Screen for Heat Nociception Identifies alpha 2 delta 3 as an Evolutionarily Conserved Pain Gene
- 2010
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Ingår i: Cell. - : Elsevier Science B.V., Amsterdam.. - 0092-8674 .- 1097-4172. ; 143:4, s. 628-638
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Tidskriftsartikel (refereegranskat)abstract
- Worldwide, acute, and chronic pain affects 20% of the adult population and represents an enormous financial and emotional burden. Using genome-wide neuronal-specific RNAi knockdown in Drosophila, we report a global screen for an innate behavior and identify hundreds of genes implicated in heat nociception, including the alpha 2 delta family calcium channel subunit straightjacket (stj). Mice mutant for the stj ortholog CACNA2D3 (alpha 2 delta 3) also exhibit impaired behavioral heat pain sensitivity. In addition, in humans, alpha 2 delta 3 SNP variants associate with reduced sensitivity to acute noxious heat and chronic back pain. Functional imaging in alpha 2 delta 3 mutant mice revealed impaired transmission of thermal pain-evoked signals from the thalamus to higher-order pain centers. Intriguingly, in alpha 2 delta 3 mutant mice, thermal pain and tactile stimulation triggered strong cross-activation, or synesthesia, of brain regions involved in vision, olfaction, and hearing.
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| 2. |
- Mueller, Kristina M, et al.
(författare)
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Impairment of Hepatic Growth Hormone and Glucocorticoid Receptor Signaling Causes Steatosis and Hepatocellular Carcinoma in Mice
- 2011
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Ingår i: Hepatology. - : Wiley-Blackwell. - 0270-9139 .- 1527-3350. ; 54:4, s. 1398-1409
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Tidskriftsartikel (refereegranskat)abstract
- Growth hormone (GH)-activated signal transducer and activator of transcription 5 (STAT5) and the glucocorticoid (GC)-responsive glucocorticoid receptor (GR) are important signal integrators in the liver during metabolic and physiologic stress. Their deregulation has been implicated in the development of metabolic liver diseases, such as steatosis and progression to fibrosis. Using liver-specific STAT5 and GR knockout mice, we addressed their role in metabolism and liver cancer onset. STAT5 single and STAT5/GR double mutants developed steatosis, but only double-mutant mice progressed to liver cancer. Mechanistically, STAT5 deficiency led to the up-regulation of prolipogenic sterol regulatory element binding protein 1 (SREBP-1) and peroxisome proliferator activated receptor gamma (PPAR-gamma) signaling. Combined loss of STAT5/GR resulted in GH resistance and hypercortisolism. The combination of both induced expression of adipose tissue lipases, adipose tissue lipid mobilization, and lipid flux to the liver, thereby aggravating STAT5-dependent steatosis. The metabolic dysfunctions in STAT5/GR compound knockout animals led to the development of hepatic dysplasia at 9 months of age. At 12 months, 35% of STAT5/GR-deficient livers harbored dysplastic nodules and similar to 60% hepatocellular carcinomas (HCCs). HCC development was associated with GH and insulin resistance, enhanced tumor necrosis factor alpha (TNF-alpha) expression, high reactive oxygen species levels, and augmented liver and DNA damage parameters. Moreover, activation of the c-Jun N-terminal kinase 1 (JNK1) and STAT3 was prominent. Conclusion: Hepatic STAT5/GR signaling is crucial for the maintenance of systemic lipid homeostasis. Impairment of both signaling cascades causes severe metabolic liver disease and promotes spontaneous hepatic tumorigenesis.
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| 3. |
- Öst, Anita, et al.
(författare)
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Paternal Diet Defines Offspring Chromatin State and Intergenerational Obesity
- 2014
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Ingår i: Cell. - : Elsevier (Cell Press). - 0092-8674 .- 1097-4172. ; 159:6, s. 1352-1364
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Tidskriftsartikel (refereegranskat)abstract
- The global rise in obesity has revitalized a search for genetic and epigenetic factors underlying the disease. We present a Drosophila model of paternal-diet-induced intergenerational metabolic reprogramming (IGMR) and identify genes required for its encoding in offspring. Intriguingly, we find that as little as 2 days of dietary intervention in fathers elicits obesity in offspring. Paternal sugar acts as a physiological suppressor of variegation, desilencing chromatin-state-defined domains in both mature sperm and in offspring embryos. We identify requirements for H3K9/K27me3-dependent reprogramming of metabolic genes in two distinct germline and zygotic windows. Critically, we find evidence that a similar system may regulate obesity susceptibility and phenotype variation in mice and humans. The findings provide insight into the mechanisms underlying intergenerational metabolic reprogramming and carry profound implications for our understanding of phenotypic variation and evolution.
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