Project description:We investigated an subacute study in male Wistar rats, treated daily with 400 ppm rotenone for 1, 3, or 14 consecutive days, followed by necropsy 24h after the last application. Rotenone is a strong mitochondrial respiratory chain complex I inhibitor. Inhibitors of complex I are suggested to exert anti-tumor activity of those tumors relying on oxidative metabolism and are therefore of interest in oncology research. Nevertheless, the safety profile of these inhibitors needs to be rigorously assessed. Rotenone has shown anti-carcinogenic activity in several studies. In this context we used rotenone in our study as tool compound with the aim to identify suitable biomarker candidates and enhance mechanistic insights into the biologic and cellular effects of complex I inhibitors at the organ level after in vivo treatment. Various parameters, including hematology, clinical chemistry and histopathology, major blood cell population phenotyping using FACS and enzymatic activity assays were measured and/or evaluated. Moreover gene expression profiles were determined to investigate pathways and functions affected by rotenone at the molecular level. As organs, liver, heart and brain stem were chosen due to the high metabolic activity, the high energy demand and due to the known neurotoxic effect of rotenone, respectively. The strongest rotenone-induced effects on gene expression were observed in the liver (1444 deregulated genes) compared to heart (650 deregulated genes) and brain stem (52 deregulated genes). These findings, together with the histopathological results, show that liver is a target organ of rotenone.
Project description:Whole livers were collected from rats treated with or without CDDO-Im. Total RNA was purified using Sepazol-RNA I Super G. Gene expression was measured in livers.
Project description:In a subacute study, male Wistar rats were treated daily by gavage with 800 mg/kg metformin for 1, 3, or 14 consecutive days, followed by necropsy 24h after the last application. The biguanide phenformin was used as antidiabetic drug due to its antihyperglycaemic effect, but was withdrawn from the market in the 1970s for safety reasons. In recent years, biguanides received great interest in oncology research after an epidemiological study showed a link between the treatment with metformin, another biguanide with a better safety profile, and a reduced cancer risk in diabetic patients. Since mitochondrial metabolism has become a target for possible cancer therapeutic approaches, especially for tumors relying on oxidative metabolism, mitochondrial complex I inhibition is under discussion to be responsible for the anti-cancer effect of metformin. The known strong complex I inhibitor Rotenone has also shown anti-cancer activity, however is associated with toxic effects. Therefore, we compared metformin and phenformin, with rotenone, to elucidate potential mechanisms rendering biguanides apparently less toxic than rotenone. In this context, various blood and tissue parameters as well as histopathology were measured and/or evaluated. Moreover, gene expression profiling was conducted in liver and heart due to the high metabolic activity and high energy demand. All investigations were based on an experimental design previously described for mechanistic investigations of the effects of rotenone. Our examinations regarding gene expression showed that 1630 transcripts were deregulated by rotenone, metformin and/or phenformin in liver, whereas 777 transcripts were deregulated in heart, indicating that the heart is less affected by these compounds. Overall, the mechanistic profile of phenformin appears to be similar to that of rotenone, yet at a quantitatively reduced level, whereas metformin displayed only transient similarities after one day of treatment. These differences are likely due to differential molecular properties of these compounds, especially concerning their effects on mitochondria: Metformin, in contrast to rotenone, requires a certain mitochondrial potential to allow accumulation in this organelle, thereby self-limiting its entry and thus ability to inhibit mitochondrial function, whereas rotenone and to some extent also phenformin can enter mitochondria freely. Thus, our more detailed molecular characterization of these compounds suggests that inhibition of mitochondrial functions can serve as target for an anti-cancer mode of action, yet should be self-limited or balanced to some extent to avoid exhaustion of all energy stores.
Project description:In a subacute study, male Wistar rats were treated daily by gavage with 800 mg/kg metformin for 1, 3, or 14 consecutive days, followed by necropsy 24h after the last application. The biguanide metformin is a widely used antidiabetic drug, which has received great interest in oncology research in recent years after an epidemiological study showed a link between metformin treatment and a reduced cancer risk in diabetic patients. Since mitochondrial metabolism has become a target for possible cancer therapeutic approaches, especially for tumors relying on oxidative metabolism, mitochondrial complex I inhibition is under discussion to be responsible for the anti-cancer effect of metformin. The known strong complex I inhibitor Rotenone has also shown anti-cancer activity, however is associated with toxic effects. Therefore, we compared metformin and phenformin, another biguanide withdrawn from the marked as antidiabetic due to safety reasons, with rotenone, to elucidate potential mechanisms rendering biguanides apparently less toxic than rotenone. In this context, various blood and tissue parameters as well as histopathology were measured and/or evaluated. Moreover, gene expression profiling was conducted in liver and heart due to the high metabolic activity and high energy demand. All investigations were based on an experimental design previously described for mechanistic investigations of the effects of rotenone. Our examinations regarding gene expression showed that 1630 transcripts were deregulated by rotenone, metformin and/or phenformin in liver, whereas 777 transcripts were deregulated in heart, indicating that the heart is less affected by these compounds. Overall, the mechanistic profile of phenformin appears to be similar to that of rotenone, yet at a quantitatively reduced level, whereas metformin displayed only transient similarities after one day of treatment. These differences are likely due to differential molecular properties of these compounds, especially concerning their effects on mitochondria: Metformin, in contrast to rotenone, requires a certain mitochondrial potential to allow accumulation in this organelle, thereby self-limiting its entry and thus ability to inhibit mitochondrial function, whereas rotenone and to some extent also phenformin can enter mitochondria freely. Thus, our more detailed molecular characterization of these compounds suggests that inhibition of mitochondrial functions can serve as target for an anti-cancer mode of action, yet should be self-limited or balanced to some extent to avoid exhaustion of all energy stores.
Project description:This program addresses the gene signature associated with LPS-treated liver in rat. Specifically, which genes are differentially expressed in livers of the Sprague Dawley rats treated with LPS?
Project description:To characterize naproxen and NO-naproxen, their effects on gene expression in livers of treated rats was examined. We have previously worked with liver and could therefore identify a moderate to strong antioxidant response element signature. There were two goals to this study: 1) to determine whether naproxen and NO-naproxen yield similar gene expression profiles, which would imply that their effects are mediated by the parent NSAID, and 2) to determine whether NO-naproxen, due to the release of NO, might cause increases in expression of genes associated with the antioxidant response element (ARE). In this dataset, we include the expression data obtained from liver of untreated rats and rats treated with naproxen (400mg/kg diet) or NO-naproxen (550mg/kg diet) for 7 days.