- Email: [email protected]
MAPK signalling
Abstracts / Experimental Gerontology 44 (2009) 126–134
(Vitamin D receptor) co-activator, and to be associated with the complex containing SNEVPrp19/Pso4, a multifunctional regulator that extends cellular life span upon overexpression. Here we show that Nopsi has a putative RNA-methyltransferase domain, and localizes to the nucleolus, suggesting a role in ribosome biogenesis. Since recently downregulation of translation has been shown to increase life-span of Caenorhabditis elegans, we tested if Nopsi knock-down influences the life span of Drosophila melanogaster. Indeed, two different RNAi constructs showed a 10–15% increase in the mean and median life span. Currently, we are testing if Nopsi knockdown indeed results in reduced protein translation. If so, our data would suggest that a reduced protein translation rate might be an evolutionarily conserved mechanism for conferring longevity. doi:10.1016/j.exger.2008.08.036
23. Acute adrenergic stress inhibits proliferation of murine haematopoietic progenitor cells via p38/MAPK signalling E. Schraml b, R. Fuchs a, P. Kotzbeck a, J. Grillari b, K. Schauenstein a a
Institute of Pathophysiology and Immunology, Center of Molecular Medicine, Medical University of Graz, Graz, Austria b Institute of Applied Microbiology, University of Natural Resources and Applied Life Sciences Vienna, Vienna, Austria Acute adrenergic stress is a cause of hematopoietic failure that accompanies severe injury. While the communication between neuronal and immune system are well documented and catecholamines are known as important regulators of homeostasis, the molecular mechanisms of haematopoietic failure are not well understood. In order to study the influence of adrenergic stress on haematopoietic progenitor cells (HPCs), that recently have been found to express adrenergic receptors, Lin , Sca+, kithigh cells were isolated and treated with a- and b-adrenergic agonists in vitro. Indeed, this stimulation resulted in significantly decreased colony formation capacity using GM-CFU assays. This decline was dependent on formation of reactive oxygen species (ROS) and activation of the p38/MAPK pathway, since addition of antioxidants or a p38 inhibitor restored CFU formation. DNA damage by adrenergically induced ROS, however, does not seem to account for reduction of colonies. Thus, catecholamine/p38/MAPK is identified as a key signal transduction pathway in HPCs besides those dependent on Wnt, Notch, and sonic hedgehog. Furthermore, a well known target of p38 signalling, p16 is transcriptionally activated after adrenergic stimulation, suggesting that cell cycle arrest might importantly contribute to haematopoietic failure and immune dysfunctions after severe injury. Since increased levels of catecholamines are also observed in other conditions, like during aging, linked with decline of immune functions, adrenergic stress might as well contribute to the lowered immune defence in the elderly. doi:10.1016/j.exger.2008.08.037
24. Stable histamine production in spite of extensive Parkinson pathology in the hypothalamic tuberomamillary nucleus L. Shan a, C. Liu b, R. Balesar a, D.F. Swaab a, A. Bao a,b a Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam,The Netherlands b Department of Neurobiology, Institute of Neuroscience, Zhejiang University School of Medicine, 388 Yu Hang Tang Road, Hangzhou 310058, PR China
The hypothalamic tuberomamillary nucleus (TMN) is the exclusive source of histamine in the brain. Previous studies have reported
133
conflicting data on the nature and direction of the alterations in the tuberomamillary nucleus (TMN) in Parkinson’s disease (PD). On one hand it was thought that the extensive presence of Lewy bodies (LBs) and Lewy neuritis (LNs) in the TMN indicated a strong degeneration of the TMN in PD, whereas other data indicated an activation of the TMN that was even presumed to accelerate degeneration of the substantia nigra in the course of PD. We aimed to clarify this controversy by quantitative in situ hybridization for the mRNA of the rate limiting enzyme histidine decarboxylase (HDC) as a marker for histamine production in post mortem human brain tissue from PD patients (early PD stages n = 6, late PD stage n = 11) and 17 controls that were matched. The brain material was obtained from the Netherlands Brain Bank.Furthermore we determined the relationship between HDC expression in the TMN and the amount of typical PD lesions, i.e. the LBs and LNs in this area. The main result of the present study was that the HDC expression in the TMN was unaltered, both in early and late stages of PD. in spite of the extensive PD lesions in this area. Acknowledgement We thank that this study is supported by a stipend from China Shcholarship Council through State Scholarship Fund (CSC) [2007]3020(to Ling Shan). doi:10.1016/j.exger.2008.08.038
25. Advances in diabetes intervention: Cryopreservation of pancreatic tissue under normal and high pressure freezing for transplantation A. Tin a, B. Bui a, X. Ouyang a, H. Tran a, K. Mei a, M. Voelker b, H. Sternberg b, P.S. Timiras a a
Department of Molecular and Cell Biology; University of California Berkeley, USA b BioTime Inc; Alameda, CA, USA One of the main causes of the abnormal metabolism of glucose as observed in diabetes is an insufficiency of insulin. Diabetes affects a large proportion of the human population in the form of early onset diabetes (type I) in which there is an autoimmune damage to insulin-producing b-cells in the pancreas. To treat type I diabetes, there have been several emerging surgical techniques which employ transplantation of either the entire organ or portions of it. With an increasing demand for pancreatic transplantation surgeries, preservation of available organs is essential. In previous studies, we have investigated several preservation techniques including freezing organs with and without high pressure and perfusion with specialized cryoprotectants. Our present data have allowed us to quantitatively and qualitatively evaluate the degree of pancreatic preservation in adult, female Sprague Dawley rats. In a comparative study between high and low pressure frozen pancreas with non-frozen tissue as a control, we employed electron and confocal microscopy to determine morphology and viability differences. Immediately after sacrifice, the pancreas was removed and rapidly cooled to 77 K either under high or atmospheric pressure. The tissue was sliced to 200 lm sections and upon thawing we stained the slices with L-3224 Live/DeadÒ Viability/Cryotoxicity kit and visualized it with an argon 488 laser. The data indicate that high pressure frozen tissue has greater viability than freezing alone. Future studies will involve functional tests by assessing insulin secretion before and after freezing. Supported by NIH AG19145-05 and BioTime, Inc. doi:10.1016/j.exger.2008.08.039
(Vitamin D receptor) co-activator, and to be associated with the complex containing SNEVPrp19/Pso4, a multifunctional regulator that extends cellular life span upon overexpression. Here we show that Nopsi has a putative RNA-methyltransferase domain, and localizes to the nucleolus, suggesting a role in ribosome biogenesis. Since recently downregulation of translation has been shown to increase life-span of Caenorhabditis elegans, we tested if Nopsi knock-down influences the life span of Drosophila melanogaster. Indeed, two different RNAi constructs showed a 10–15% increase in the mean and median life span. Currently, we are testing if Nopsi knockdown indeed results in reduced protein translation. If so, our data would suggest that a reduced protein translation rate might be an evolutionarily conserved mechanism for conferring longevity. doi:10.1016/j.exger.2008.08.036
23. Acute adrenergic stress inhibits proliferation of murine haematopoietic progenitor cells via p38/MAPK signalling E. Schraml b, R. Fuchs a, P. Kotzbeck a, J. Grillari b, K. Schauenstein a a
Institute of Pathophysiology and Immunology, Center of Molecular Medicine, Medical University of Graz, Graz, Austria b Institute of Applied Microbiology, University of Natural Resources and Applied Life Sciences Vienna, Vienna, Austria Acute adrenergic stress is a cause of hematopoietic failure that accompanies severe injury. While the communication between neuronal and immune system are well documented and catecholamines are known as important regulators of homeostasis, the molecular mechanisms of haematopoietic failure are not well understood. In order to study the influence of adrenergic stress on haematopoietic progenitor cells (HPCs), that recently have been found to express adrenergic receptors, Lin , Sca+, kithigh cells were isolated and treated with a- and b-adrenergic agonists in vitro. Indeed, this stimulation resulted in significantly decreased colony formation capacity using GM-CFU assays. This decline was dependent on formation of reactive oxygen species (ROS) and activation of the p38/MAPK pathway, since addition of antioxidants or a p38 inhibitor restored CFU formation. DNA damage by adrenergically induced ROS, however, does not seem to account for reduction of colonies. Thus, catecholamine/p38/MAPK is identified as a key signal transduction pathway in HPCs besides those dependent on Wnt, Notch, and sonic hedgehog. Furthermore, a well known target of p38 signalling, p16 is transcriptionally activated after adrenergic stimulation, suggesting that cell cycle arrest might importantly contribute to haematopoietic failure and immune dysfunctions after severe injury. Since increased levels of catecholamines are also observed in other conditions, like during aging, linked with decline of immune functions, adrenergic stress might as well contribute to the lowered immune defence in the elderly. doi:10.1016/j.exger.2008.08.037
24. Stable histamine production in spite of extensive Parkinson pathology in the hypothalamic tuberomamillary nucleus L. Shan a, C. Liu b, R. Balesar a, D.F. Swaab a, A. Bao a,b a Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam,The Netherlands b Department of Neurobiology, Institute of Neuroscience, Zhejiang University School of Medicine, 388 Yu Hang Tang Road, Hangzhou 310058, PR China
The hypothalamic tuberomamillary nucleus (TMN) is the exclusive source of histamine in the brain. Previous studies have reported
133
conflicting data on the nature and direction of the alterations in the tuberomamillary nucleus (TMN) in Parkinson’s disease (PD). On one hand it was thought that the extensive presence of Lewy bodies (LBs) and Lewy neuritis (LNs) in the TMN indicated a strong degeneration of the TMN in PD, whereas other data indicated an activation of the TMN that was even presumed to accelerate degeneration of the substantia nigra in the course of PD. We aimed to clarify this controversy by quantitative in situ hybridization for the mRNA of the rate limiting enzyme histidine decarboxylase (HDC) as a marker for histamine production in post mortem human brain tissue from PD patients (early PD stages n = 6, late PD stage n = 11) and 17 controls that were matched. The brain material was obtained from the Netherlands Brain Bank.Furthermore we determined the relationship between HDC expression in the TMN and the amount of typical PD lesions, i.e. the LBs and LNs in this area. The main result of the present study was that the HDC expression in the TMN was unaltered, both in early and late stages of PD. in spite of the extensive PD lesions in this area. Acknowledgement We thank that this study is supported by a stipend from China Shcholarship Council through State Scholarship Fund (CSC) [2007]3020(to Ling Shan). doi:10.1016/j.exger.2008.08.038
25. Advances in diabetes intervention: Cryopreservation of pancreatic tissue under normal and high pressure freezing for transplantation A. Tin a, B. Bui a, X. Ouyang a, H. Tran a, K. Mei a, M. Voelker b, H. Sternberg b, P.S. Timiras a a
Department of Molecular and Cell Biology; University of California Berkeley, USA b BioTime Inc; Alameda, CA, USA One of the main causes of the abnormal metabolism of glucose as observed in diabetes is an insufficiency of insulin. Diabetes affects a large proportion of the human population in the form of early onset diabetes (type I) in which there is an autoimmune damage to insulin-producing b-cells in the pancreas. To treat type I diabetes, there have been several emerging surgical techniques which employ transplantation of either the entire organ or portions of it. With an increasing demand for pancreatic transplantation surgeries, preservation of available organs is essential. In previous studies, we have investigated several preservation techniques including freezing organs with and without high pressure and perfusion with specialized cryoprotectants. Our present data have allowed us to quantitatively and qualitatively evaluate the degree of pancreatic preservation in adult, female Sprague Dawley rats. In a comparative study between high and low pressure frozen pancreas with non-frozen tissue as a control, we employed electron and confocal microscopy to determine morphology and viability differences. Immediately after sacrifice, the pancreas was removed and rapidly cooled to 77 K either under high or atmospheric pressure. The tissue was sliced to 200 lm sections and upon thawing we stained the slices with L-3224 Live/DeadÒ Viability/Cryotoxicity kit and visualized it with an argon 488 laser. The data indicate that high pressure frozen tissue has greater viability than freezing alone. Future studies will involve functional tests by assessing insulin secretion before and after freezing. Supported by NIH AG19145-05 and BioTime, Inc. doi:10.1016/j.exger.2008.08.039