Project description:To understand faster reinduction of heat acclimation, in this investigation we studied global stress associated genomic response during acclimation, following its loss and re-induction. Nylon cDNA Atlas Array was used. Collectively, the study comprised nine experimental groups of which six characterized experimental basal conditions: Controls-untreated, Short and Long term heat acclimated groups ( exposure to environmental heat at 34oC for 2 or 30 days respectively), Deacclimated group (24oC for 1mo) and Reacclimated groups (2d at 34oC following the deacclimation protocol). Three additional experimental groups: Controls, Short and Long term and Reacclimated rats (as above) were tested for genomic responses following subjection to heat stress at 41oC. Because of a dichotomy between genomic and physiological responses we hypothesize thst rapid reacclimation is linked to reprograming of gene expression. Keywords: heart, Left ventricle
Project description:The processes of adaptation to environmental heat and aerobic exercise training improve efficiency in various body systems and bring about acclimatory homeostasis. In order to examine the global genomic responses of the soleus and heart following exposure of rats to these stressors, nylon cDNA Atlas Array was used. Male rats were exposed to one of the following stressors: heat acclimation, aerobic training (treadmill), and combined heat acclimation and aerobic training for short (2, 3 days) and long (1 mo) time period. The study comprised seven experimental groups: Controls-untreated. Heat acclimated groups (2dac, Acc)â exposure to environmental heat at 34C for 2 or 30 days. Exercise groups (3dex, Ex)â graduated training protocol under normothermic conditions for 3 and 30 days at 24C. Exercise training and heat acclimation â (3dexac, ExAc)- exposed to both environmental heat and aerobic exercise as above. The Series data tables appended below: 1) Heart - normalized log2 ratio of geomeans defined as treatment/control 2) Soleus - normalized log2 ratio of geomeans defined as treatment/control 21 samples, 3 pool each, of: 1)Â Control untreated rats 2)Â Long-term heat acclimated rats 3)Â Long-term aerobic-exercised trained rats. 4)Â Rats exposed to long-term heat acclimation and exercise training. 5)Â Short term heat acclimated rats. 6)Â Short term aerobic exercised trained rats 7)Â Rats exposed to short-term heat acclimation and exercise training.
Project description:The processes of adaptation to environmental heat and aerobic exercise training improve efficiency in various body systems and bring about acclimatory homeostasis. In order to examine the global genomic responses of the soleus and heart following exposure of rats to these stressors, nylon cDNA Atlas Array was used. Male rats were exposed to one of the following stressors: heat acclimation, aerobic training (treadmill), and combined heat acclimation and aerobic training for short (2, 3 days) and long (1 mo) time period. The study comprised seven experimental groups: Controls-untreated. Heat acclimated groups (2dac, Acc)– exposure to environmental heat at 34C for 2 or 30 days. Exercise groups (3dex, Ex)– graduated training protocol under normothermic conditions for 3 and 30 days at 24C. Exercise training and heat acclimation – (3dexac, ExAc)- exposed to both environmental heat and aerobic exercise as above. The Series data tables appended below: 1) Heart - normalized log2 ratio of geomeans defined as treatment/control 2) Soleus - normalized log2 ratio of geomeans defined as treatment/control Keywords: stress response
Project description:Heat acclimation (AC) allows its faster re-induction following its decline. Constitutively preserved euchromatin state in hsp70 promoter during acclimation decline/regain pushed forward the hypothesis that acclimation decline is a period of M-bM-^@M-^\dormant memoryM-bM-^@M-^] involving molecular program including epigenetic controlled transcriptional regulation leading to heat acclimation mediated cytoprotective memory. We used microarray to uncover hallmark pathways in the induction of heat-acclimation-mediated memory, focusing on markers of epigenetic processes. Rats subjected to heat acclimation, deacclimation, reacclimation and untreated controls were used. We showed here that (i) AC2d provides the molecular switch for acclimation (ii) AC30 heart demonstrates qualitative adaptations (iii) specific molecular program encompassing up/down regulated gene during DeAC, of which epigenetic markers such as class A histones, chromatin modifiers and microRNA suggest epigenetic transcriptional regulation linked to acclimation memory (iv) constitutive upregulation of MAPK P38 module and targets as well as jak/stat and AKT associated pathways during DeAC imply its major role in this process. Noteworthy are players such as poly-(ADP-ribose)polymerase-1 (PARP1) and linker histones (histones H1 cluster in this process).
Project description:Heat acclimation (AC) allows its faster re-induction following its decline. Constitutively preserved euchromatin state in hsp70 promoter during acclimation decline/regain pushed forward the hypothesis that acclimation decline is a period of “dormant memory” involving molecular program including epigenetic controlled transcriptional regulation leading to heat acclimation mediated cytoprotective memory. We used microarray to uncover hallmark pathways in the induction of heat-acclimation-mediated memory, focusing on markers of epigenetic processes.
Project description:We studied the global genomic response in the hypothalamus during heat acclimation, with and without combined hypohydration stress. Rats were acclimated for 2 days or for 30 days at 34°C. Hypohydration (10% decrease in body weight) was attained by water deprivation. Functional analyses demonstrated a bi-phasic acclimatory profile with a transient upregulation of genes encoding ion channels, transporters, and transmitter signaling upon 2 days acclimation, suggesting enhanced neuronal excitability at that acclimation phase. Following long acclimation most genes returned to their pre-acclimation expression levels. In both acclimation phases, genes encoding hormones and neuropeptides, linked with metabolic rate and food intake, were downregulated. The response to hypohydration was characterized by an upregulation of a large number of genes primarily associated with the regulation of ion channels and cell-volume and neuronal excitability. During 2 days acclimation, the response was transiently desensitized, recovering upon LTHA. The results suggest that hypohydration overrides the heat acclimatory status. Keywords: other
Project description:Rats underwent surgery for LAD ligation for 30 min followed by reperfusion. Heart ventricles were collected 2d or 7d after reperfusion. Experiment Overall Design: rats were divided in following groups that underwent LAD occlusion or not (SHAM): Experiment Overall Design: 1. 7d-IR (n=3) Experiment Overall Design: 2. 7d-sham (n=3) Experiment Overall Design: 3. 2d-IR (n=3) Experiment Overall Design: 4. 7d-sham (n=3)