Project description:Background: Muscle responses to exercise are complex, and potentially include acute responses to exercise-induced injury as well as longer-term adaptive training responses. Using Alaskan sled dogs as an experimental model, changes in muscle gene expression were analyzed to better understand the temporal changes that occur after severe exercise. Methods: Dogs were randomly assigned to undertake in a 160 km run (n=9), or to remain at rest (n=4). Biceps femoris muscle was obtained by needle biopsy from the unexercised dogs and two dogs at each of 2, 6 and 12 hours after the exercise and from 3 dogs 24 hours after exercise. RNA was extracted and microarray analysis used to define gene transcriptional changes. Results: Nine hundred sixty three transcripts exhibited statistically significant change over time after exercise as compared to the unexercised dogs. The changes in gene expression after exercise occurred in a clear temporal pattern and included transcripts with increased expression 2 hours after exercise with a return towards resting levels by 6 hours after exercise. Other transcripts demonstrated increased expression which peaked at six hours after exercise, while other transcripts showed sustained induction or repression over the 24 hours after exercise. Increases in a number of known transcriptional regulators, including PPAR-Î±, CERM and CEBPD, were observed 2-hours after exercise. Pathway analysis demonstrated coordinated changes in expression of genes with known functional relationships, including genes involved in muscle remodeling and growth, intermediary metabolism and immune regulation. Conclusion: Sustained endurance exercise by Alaskan sled dogs induces coordinated changes in gene expression with a clear temporal pattern. RNA expression profiling has the potential to identify novel regulatory mechanisms and responses to exercise stimuli. Subjects were 13 Alaskan sled dogs aged 4.5 + 2.5 years (mean + SD) and weighing 23.3 + 2.5 kg. Dogs were randomly assigned to two groups â one group of 9 dogs subsequently ran 160 km in 24 hours as 2 sessions of 80 km, separated by a 6 hour rest period. The second group consisted of four dogs housed in unheated kennels, their usual housing, for the duration of the experiment. All dogs were from the same kennel. Dogs were fed a commercial kibble (Eukanuba, Iams Company, Dayton, OH) supplemented with frozen meat during the 8 weeks preceding the study and throughout the study period. The dogâs diet was consistent before, during and after the exercise bout. All dogs had completed 1590 + 100 km of training runs in the 3 months before the study. The dogs had not exercised for 72 hors before the start of this study. Dogs in the exercise group ran as a team pulling a lightly laden sled and driver over packed snow. Ambient temperatures were -20o to -10o C with no wind. Dogs completed the two 80 km runs in 23 hours, including the 6 hour rest period. Blood samples were collected by jugular venepuncture from all dogs the day before exercise, and within a 10 minute window at 2, 6, 12, and 24 hours after completing the second run. Samples were collected into evacuated glass tubes containing a clot enhancer. Muscle samples were collected from each of two dogs within a 10 minute window at 2, 6 and 12 hours after completing exercise and from three dogs 24 hours after completing exercise. Muscle samples were collected from each of the four unexercised dogs within two hours of the other dogs initiating their exercise bout. Each dog had only one biopsy procedure performed. Muscle samples were collected from the biceps femoris muscle using a needle biopsy that yielded approximately 40-60 mg of muscle. The biopsy was performed after clipping and aseptic preparation of the skin overlying the biopsy site. The dog was anesthetized with propofol (6 mg/kg, IV, maintained as necessary with 2 mg/kg additional boluses), a cuffed orotracheal tube placed and the dog ventilated with a hand-held ventilation bag. When adequate anesthesia had been obtained a 5 mm incision was made in the skin. A sterile biopsy needle (12 g PGI EZ Core, Products group International, Inc. Lyons, CO) was then inserted through the incision and a sample of muscle collected. If necessary, repeated collections of muscle were made until a minimum of 40 mg of muscle has been collected from an individual dog. The skin incision was closed with tissue glue and an antibiotic ointment applied. The dog was monitored closely until recovery from anesthesia was complete. Carprofen (4.4 mg/kg, orally) was administered when the dog had recovered sufficiently from anesthesia to have a gag reflex.

Project description:Pancreatic cancer is the 3rd most prevalent cause of cancer related deaths in United states alone, with over 55000 patients being diagnosed in 2019 alone and nearly as many succumbing to it. Late detection, lack of effective therapy and poor understanding of pancreatic cancer systemically contributes to its poor survival statistics. Obesity and high caloric intake linked co-morbidities like type 2 diabetes (T2D) have been attributed as being risk factors for a number of cancers including pancreatic cancer. Studies on gut microbiome has shown that lifestyle factors as well as diet has a huge effect on the microbial flora of the gut. Further, modulation of gut microbiome has been seen to contribute to effects of intensive insulin therapy in mice on high fat diet. In another study, abnormal gut microbiota was reported to contribute to development of diabetes in Db/Db mice. Recent studies indicate that microbiome and microbial dysbiosis plays a role in not only the onset of disease but also in its outcome. In colorectal cancer, Fusobacterium has been reported to promote therapy resistance. Certain intra-tumoral bacteria have also been shown to elicit chemo-resistance by metabolizing anti-cancerous agents. In pancreatic cancer, studies on altered gut microbiome have been relatively recent. Microbial dysbiosis has been observed to be associated with pancreatic tumor progression. Modulation of microbiome has been shown to affect response to anti-PD1 therapy in this disease as well. However, most of the studies in pancreatic cancer and microbiome have remained focused om immune modulation. In the current study, we observed that in a T2D mouse model, the microbiome changed significantly as the hyperglycemia developed in these animals. Our results further showed that, tumors implanted in the T2D mice responded poorly to Gemcitabine/Paclitaxel (Gem/Pac) standard of care compared to those in the control group. A metabolomic reconstruction of the WGS of the gut microbiota further revealed that an enrichment of bacterial population involved in drug metabolism in the T2D group.

Dataset Information

Alaskan Ephemeroptera Microbiome

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure