The Experts below are selected from a list of 8028 Experts worldwide ranked by ideXlab platform
Sharon E. Plon - One of the best experts on this subject based on the ideXlab platform.
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generalized metabolic bone disease in neurofibromatosis type i
Molecular Genetics and Metabolism, 2008Co-Authors: Nicola Brunettipierri, Kelly Phan, Roberto Mendozalondono, Maria Blazo, Alyssa Tran, Susan Carter, John Hicks, Richard A Lewis, Stephen B Doty, Sharon E. PlonAbstract:Abstract Skeletal abnormalities are a recognized component of Neurofibromatosis type I (NF1) but a generalized metabolic bone defect in NF1 has not been fully characterized thus far. The purpose of this study was to characterize at the densitometric, biochemical and pathological level the bone involvement in NF1 patients. Using dual energy X-ray absorptiometry (DXA) we analyzed bone status in 73 unselected NF1 subjects, 26 males and 47 females, mainly children and adolescents (mean age: 16.6 years). In a subgroup of subjects with low bone mass, we measured indices of calcium–phosphate metabolism, bone turnover, and bone density before and after vitamin D and calcium treatment. We found statistically significant and generalized reduction in bone mass with the mean lumbar bone mineral density (BMD) z -score being −1.38 ± 1.05 (CI 95% −1.62 to −1.13), and whole body bone mineral content (BMC) z -score −0.61 ± 1.19 (CI 95% −0.94 to −0.29), both significantly reduced compared to normal controls ( p z -scores did not significantly improve after 2 years of follow-up. Histological analysis of bone samples from NF1 patients revealed Substantial Alteration of bone microarchitecture due mainly to reduced trabecular bone. Our observations are consistent with a generalized bone metabolic defect due to loss of the function of neurofibromin. Early identification of patients with osteoporosis may permit more timely and aggressive treatments to prevent the likely Substantial morbidity associated with increased fracture risk later in life.
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generalized metabolic bone disease in neurofibromatosis type i
Molecular Genetics and Metabolism, 2008Co-Authors: Nicola Brunettipierri, Kelly Phan, Roberto Mendozalondono, Maria Blazo, Alyssa Tran, Susan Carter, John Hicks, Richard A Lewis, Stephen B Doty, Sharon E. PlonAbstract:Abstract Skeletal abnormalities are a recognized component of Neurofibromatosis type I (NF1) but a generalized metabolic bone defect in NF1 has not been fully characterized thus far. The purpose of this study was to characterize at the densitometric, biochemical and pathological level the bone involvement in NF1 patients. Using dual energy X-ray absorptiometry (DXA) we analyzed bone status in 73 unselected NF1 subjects, 26 males and 47 females, mainly children and adolescents (mean age: 16.6 years). In a subgroup of subjects with low bone mass, we measured indices of calcium–phosphate metabolism, bone turnover, and bone density before and after vitamin D and calcium treatment. We found statistically significant and generalized reduction in bone mass with the mean lumbar bone mineral density (BMD) z -score being −1.38 ± 1.05 (CI 95% −1.62 to −1.13), and whole body bone mineral content (BMC) z -score −0.61 ± 1.19 (CI 95% −0.94 to −0.29), both significantly reduced compared to normal controls ( p z -scores did not significantly improve after 2 years of follow-up. Histological analysis of bone samples from NF1 patients revealed Substantial Alteration of bone microarchitecture due mainly to reduced trabecular bone. Our observations are consistent with a generalized bone metabolic defect due to loss of the function of neurofibromin. Early identification of patients with osteoporosis may permit more timely and aggressive treatments to prevent the likely Substantial morbidity associated with increased fracture risk later in life.
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generalized metabolic bone disease in neurofibromatosis type i
Molecular Genetics and Metabolism, 2008Co-Authors: Nicola Brunettipierri, Kelly Phan, Roberto Mendozalondono, Maria Blazo, Susan Carter, John Hicks, Richard A Lewis, Stephen B Doty, Alyssa A Tran, Sharon E. PlonAbstract:Skeletal abnormalities are a recognized component of Neurofibromatosis type I (NF1) but a generalized metabolic bone defect in NF1 has not been fully characterized thus far. The purpose of this study was to characterize at the densitometric, biochemical and pathological level the bone involvement in NF1 patients. Using dual energy X-ray absorptiometry (DXA) we analyzed bone status in 73 unselected NF1 subjects, 26 males and 47 females, mainly children and adolescents (mean age: 16.6 years). In a subgroup of subjects with low bone mass, we measured indices of calcium-phosphate metabolism, bone turnover, and bone density before and after vitamin D and calcium treatment. We found statistically significant and generalized reduction in bone mass with the mean lumbar bone mineral density (BMD) z-score being -1.38+/-1.05 (CI 95% -1.62 to -1.13), and whole body bone mineral content (BMC) z-score -0.61+/-1.19 (CI 95% -0.94 to -0.29), both significantly reduced compared to normal controls (p<.001). PTH was moderately elevated and after 4 months of supplemental therapy with calcium and vitamin D, it decreased to the normal range. However, BMD z-scores did not significantly improve after 2 years of follow-up. Histological analysis of bone samples from NF1 patients revealed Substantial Alteration of bone microarchitecture due mainly to reduced trabecular bone. Our observations are consistent with a generalized bone metabolic defect due to loss of the function of neurofibromin. Early identification of patients with osteoporosis may permit more timely and aggressive treatments to prevent the likely Substantial morbidity associated with increased fracture risk later in life.
Stefan Wolfl - One of the best experts on this subject based on the ideXlab platform.
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a trxr inhibiting gold i nhc complex induces apoptosis through ask1 p38 mapk signaling in pancreatic cancer cells
Molecular Cancer, 2014Co-Authors: Xinlai Cheng, Palvo Holenya, Hamed Alborzinia, Riccardo Rubbiani, Stefan WolflAbstract:Background: Cancer cells in the advanced stage show aberrant antioxidant capacity to detoxify excessive ROS resulting in the compensation for intrinsic oxidative stress and therapeutic resistance. PDAC is one of the most lethal cancers and often associated with a high accumulation of ROS. Recent studies identified gold(I) NHC complexes as potent TrxR inhibitors suppressing cell growth in a wide spectrum of human malignant cell lines at the low micromolar concentration. However, the mechanism of action is not completely elucidated yet. Methods: To understand the biological function of gold(I) NHC complexes in PDAC, we used a recently published gold(I) NHC complex, MC3, and evaluated its anti-proliferative effect in four PDAC cell lines, determined by MTT and SRB assays. In further detailed analysis, we analyzed cellular ROS levels using the ROS indicator DHE and mitochondrial membrane potential indicated by the dye JC-1 in Panc1. We also analyzed cell cycle arrest and apoptosis by FACS. To elucidate the role of specific cell signaling pathways in MC3-induced cell death, co-incubation with ROS scavengers, a p38-MAPK inhibitor and siRNA mediated depletion of ASK1 were performed, and results were analyzed by immunoblotting, ELISA-microarrays, qRT-PCR and immunoprecipitation. Results: Our data demonstrate that MC3 efficiently suppressed cell growth, and induced cell cycle arrest and apoptosis in pancreatic cancer cells, in particular in the gemcitabine-resistant cancer cells Panc1 and ASPC1. Treatment with MC3 resulted in a Substantial Alteration of the cellular redox homeostasis leading to increased ROS levels and a decrease in the mitochondrial membrane potential. ROS scavengers suppressed ROS formation and rescued cells from damage. On the molecular level, MC3 blocked the interaction of Trx with ASK1 and subsequently activated p38-associated signaling. Furthermore, inhibition of this pathway by using ASK1 siRNA or a p38 inhibitor clearly attenuated the effect of MC3 on cell proliferation in Panc1 and ASPC1. Conclusions: Our results confirm that MC3 is a TrxR inhibitor and show MC3 induced apoptosis in gemcitabine-resistant PDACs. MC3 mediated cell death could be blocked by using anti-oxidants, ASK1 siRNA or p38 inhibitor suggesting that the Trx-ASK1-p38 signal cascade played an important role in gold(I) NHC complexes-mediated cellular damage.
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a trxr inhibiting gold i nhc complex induces apoptosis through ask1 p38 mapk signaling in pancreatic cancer cells
Molecular Cancer, 2014Co-Authors: Xinlai Cheng, Palvo Holenya, Hamed Alborzinia, Riccardo Rubbiani, Suzan Can, Ingo Ott, Stefan WolflAbstract:Background: Cancer cells in the advanced stage show aberrant antioxidant capacity to detoxify excessive ROS resulting in the compensation for intrinsic oxidative stress and therapeutic resistance. PDAC is one of the most lethal cancers and often associated with a high accumulation of ROS. Recent studies identified gold(I) NHC complexes as potent TrxR inhibitors suppressing cell growth in a wide spectrum of human malignant cell lines at the low micromolar concentration. However, the mechanism of action is not completely elucidated yet. Methods: To understand the biological function of gold(I) NHC complexes in PDAC, we used a recently published gold(I) NHC complex, MC3, and evaluated its anti-proliferative effect in four PDAC cell lines, determined by MTT and SRB assays. In further detailed analysis, we analyzed cellular ROS levels using the ROS indicator DHE and mitochondrial membrane potential indicated by the dye JC-1 in Panc1. We also analyzed cell cycle arrest and apoptosis by FACS. To elucidate the role of specific cell signaling pathways in MC3-induced cell death, co-incubation with ROS scavengers, a p38-MAPK inhibitor and siRNA mediated depletion of ASK1 were performed, and results were analyzed by immunoblotting, ELISA-microarrays, qRT-PCR and immunoprecipitation. Results: Our data demonstrate that MC3 efficiently suppressed cell growth, and induced cell cycle arrest and apoptosis in pancreatic cancer cells, in particular in the gemcitabine-resistant cancer cells Panc1 and ASPC1. Treatment with MC3 resulted in a Substantial Alteration of the cellular redox homeostasis leading to increased ROS levels and a decrease in the mitochondrial membrane potential. ROS scavengers suppressed ROS formation and rescued cells from damage. On the molecular level, MC3 blocked the interaction of Trx with ASK1 and subsequently activated p38-associated signaling. Furthermore, inhibition of this pathway by using ASK1 siRNA or a p38 inhibitor clearly attenuated the effect of MC3 on cell proliferation in Panc1 and ASPC1. Conclusions: Our results confirm that MC3 is a TrxR inhibitor and show MC3 induced apoptosis in gemcitabine-resistant PDACs. MC3 mediated cell death could be blocked by using anti-oxidants, ASK1 siRNA or p38 inhibitor suggesting that the Trx-ASK1-p38 signal cascade played an important role in gold(I) NHC complexes-mediated cellular damage.
Simone S Grecco - One of the best experts on this subject based on the ideXlab platform.
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neolignans from leaves of nectandra leucantha lauraceae display in vitro antitrypanosomal activity via plasma membrane and mitochondrial damages
Chemico-Biological Interactions, 2017Co-Authors: Simone S Grecco, Thais A Costasilva, Gerold Jerz, Fernanda S De Sousa, Vinicius S Londero, Mariana K Galuppo, Marta L Lima, Bruno J NevesAbstract:Abstract Chagas disease is a neglected tropical disease, caused by the protozoan parasite Trypanosoma cruzi, which affects more than eight million people in Tropical and Subtropical countries especially in Latin America. Current treatment is limited to nifurtimox and benznidazole, both with reduced effectiveness and high toxicity. In this work, the n-hexane extract from leaves of Nectandra leucantha (Lauraceae) displayed in vitro antitrypanosomal activity against T. cruzi. Using several chromatographic steps, four related neolignans were isolated and chemically characterized as dehydrodieugenol B (1), 1-(8-propenyl)-3-[3′-methoxy-1′-(8-propenyl)-phenoxy]-4,5-dimethoxybenzene (2), 1-[(7S)-hydroxy-8-propenyl]-3-[3′-methoxy-1′-(8′-propenyl)-phenoxy]-4-hydroxy-5-methoxybenzene (3), and 1-[(7S)-hydroxy-8-propenyl]-3-[3′-methoxy-1′-(8′-propenyl)-phenoxy]-4,5-dimethoxybenzene (4). These compounds were tested against intracellular amastigotes and extracellular trypomastigotes of T. cruzi and for mammalian cytotoxicity. Neolignan 4 showed the higher selectivity index (SI) against trypomastigotes (>5) and amastigotes (>13) of T. cruzi. The investigation of the mechanism of action demonstrated that neolignan 4 caused Substantial Alteration of the plasma membrane permeability, together with mitochondrial dysfunctions in trypomastigote forms. In silico studies of pharmacokinetics and toxicity (ADMET) properties predicted that all compounds were non-mutagenic, non-carcinogenic, non-genotoxic, weak hERG blockers, with acceptable volume of distribution (1.66–3.32 L/kg), and low rodent oral toxicity (LD50 810–2200 mg/kg). Considering some clinical events of cerebral Chagas disease, the compounds also demonstrated favorable properties, such as blood-brain barrier penetration. Unfavorable properties were also predicted as high promiscuity for P450 isoforms, high plasma protein binding affinity (>91%), and moderate-to-low oral bioavailability. Finally, none of the isolated neolignans was predicted as interference compounds (PAINS). Considering the promising chemical and biological properties of the isolated neolignans, these compounds could be used as starting points to develop new lead compounds for Chagas disease.
Nicola Brunettipierri - One of the best experts on this subject based on the ideXlab platform.
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generalized metabolic bone disease in neurofibromatosis type i
Molecular Genetics and Metabolism, 2008Co-Authors: Nicola Brunettipierri, Kelly Phan, Roberto Mendozalondono, Maria Blazo, Alyssa Tran, Susan Carter, John Hicks, Richard A Lewis, Stephen B Doty, Sharon E. PlonAbstract:Abstract Skeletal abnormalities are a recognized component of Neurofibromatosis type I (NF1) but a generalized metabolic bone defect in NF1 has not been fully characterized thus far. The purpose of this study was to characterize at the densitometric, biochemical and pathological level the bone involvement in NF1 patients. Using dual energy X-ray absorptiometry (DXA) we analyzed bone status in 73 unselected NF1 subjects, 26 males and 47 females, mainly children and adolescents (mean age: 16.6 years). In a subgroup of subjects with low bone mass, we measured indices of calcium–phosphate metabolism, bone turnover, and bone density before and after vitamin D and calcium treatment. We found statistically significant and generalized reduction in bone mass with the mean lumbar bone mineral density (BMD) z -score being −1.38 ± 1.05 (CI 95% −1.62 to −1.13), and whole body bone mineral content (BMC) z -score −0.61 ± 1.19 (CI 95% −0.94 to −0.29), both significantly reduced compared to normal controls ( p z -scores did not significantly improve after 2 years of follow-up. Histological analysis of bone samples from NF1 patients revealed Substantial Alteration of bone microarchitecture due mainly to reduced trabecular bone. Our observations are consistent with a generalized bone metabolic defect due to loss of the function of neurofibromin. Early identification of patients with osteoporosis may permit more timely and aggressive treatments to prevent the likely Substantial morbidity associated with increased fracture risk later in life.
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generalized metabolic bone disease in neurofibromatosis type i
Molecular Genetics and Metabolism, 2008Co-Authors: Nicola Brunettipierri, Kelly Phan, Roberto Mendozalondono, Maria Blazo, Alyssa Tran, Susan Carter, John Hicks, Richard A Lewis, Stephen B Doty, Sharon E. PlonAbstract:Abstract Skeletal abnormalities are a recognized component of Neurofibromatosis type I (NF1) but a generalized metabolic bone defect in NF1 has not been fully characterized thus far. The purpose of this study was to characterize at the densitometric, biochemical and pathological level the bone involvement in NF1 patients. Using dual energy X-ray absorptiometry (DXA) we analyzed bone status in 73 unselected NF1 subjects, 26 males and 47 females, mainly children and adolescents (mean age: 16.6 years). In a subgroup of subjects with low bone mass, we measured indices of calcium–phosphate metabolism, bone turnover, and bone density before and after vitamin D and calcium treatment. We found statistically significant and generalized reduction in bone mass with the mean lumbar bone mineral density (BMD) z -score being −1.38 ± 1.05 (CI 95% −1.62 to −1.13), and whole body bone mineral content (BMC) z -score −0.61 ± 1.19 (CI 95% −0.94 to −0.29), both significantly reduced compared to normal controls ( p z -scores did not significantly improve after 2 years of follow-up. Histological analysis of bone samples from NF1 patients revealed Substantial Alteration of bone microarchitecture due mainly to reduced trabecular bone. Our observations are consistent with a generalized bone metabolic defect due to loss of the function of neurofibromin. Early identification of patients with osteoporosis may permit more timely and aggressive treatments to prevent the likely Substantial morbidity associated with increased fracture risk later in life.
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generalized metabolic bone disease in neurofibromatosis type i
Molecular Genetics and Metabolism, 2008Co-Authors: Nicola Brunettipierri, Kelly Phan, Roberto Mendozalondono, Maria Blazo, Susan Carter, John Hicks, Richard A Lewis, Stephen B Doty, Alyssa A Tran, Sharon E. PlonAbstract:Skeletal abnormalities are a recognized component of Neurofibromatosis type I (NF1) but a generalized metabolic bone defect in NF1 has not been fully characterized thus far. The purpose of this study was to characterize at the densitometric, biochemical and pathological level the bone involvement in NF1 patients. Using dual energy X-ray absorptiometry (DXA) we analyzed bone status in 73 unselected NF1 subjects, 26 males and 47 females, mainly children and adolescents (mean age: 16.6 years). In a subgroup of subjects with low bone mass, we measured indices of calcium-phosphate metabolism, bone turnover, and bone density before and after vitamin D and calcium treatment. We found statistically significant and generalized reduction in bone mass with the mean lumbar bone mineral density (BMD) z-score being -1.38+/-1.05 (CI 95% -1.62 to -1.13), and whole body bone mineral content (BMC) z-score -0.61+/-1.19 (CI 95% -0.94 to -0.29), both significantly reduced compared to normal controls (p<.001). PTH was moderately elevated and after 4 months of supplemental therapy with calcium and vitamin D, it decreased to the normal range. However, BMD z-scores did not significantly improve after 2 years of follow-up. Histological analysis of bone samples from NF1 patients revealed Substantial Alteration of bone microarchitecture due mainly to reduced trabecular bone. Our observations are consistent with a generalized bone metabolic defect due to loss of the function of neurofibromin. Early identification of patients with osteoporosis may permit more timely and aggressive treatments to prevent the likely Substantial morbidity associated with increased fracture risk later in life.
Xinlai Cheng - One of the best experts on this subject based on the ideXlab platform.
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a trxr inhibiting gold i nhc complex induces apoptosis through ask1 p38 mapk signaling in pancreatic cancer cells
Molecular Cancer, 2014Co-Authors: Xinlai Cheng, Palvo Holenya, Hamed Alborzinia, Riccardo Rubbiani, Stefan WolflAbstract:Background: Cancer cells in the advanced stage show aberrant antioxidant capacity to detoxify excessive ROS resulting in the compensation for intrinsic oxidative stress and therapeutic resistance. PDAC is one of the most lethal cancers and often associated with a high accumulation of ROS. Recent studies identified gold(I) NHC complexes as potent TrxR inhibitors suppressing cell growth in a wide spectrum of human malignant cell lines at the low micromolar concentration. However, the mechanism of action is not completely elucidated yet. Methods: To understand the biological function of gold(I) NHC complexes in PDAC, we used a recently published gold(I) NHC complex, MC3, and evaluated its anti-proliferative effect in four PDAC cell lines, determined by MTT and SRB assays. In further detailed analysis, we analyzed cellular ROS levels using the ROS indicator DHE and mitochondrial membrane potential indicated by the dye JC-1 in Panc1. We also analyzed cell cycle arrest and apoptosis by FACS. To elucidate the role of specific cell signaling pathways in MC3-induced cell death, co-incubation with ROS scavengers, a p38-MAPK inhibitor and siRNA mediated depletion of ASK1 were performed, and results were analyzed by immunoblotting, ELISA-microarrays, qRT-PCR and immunoprecipitation. Results: Our data demonstrate that MC3 efficiently suppressed cell growth, and induced cell cycle arrest and apoptosis in pancreatic cancer cells, in particular in the gemcitabine-resistant cancer cells Panc1 and ASPC1. Treatment with MC3 resulted in a Substantial Alteration of the cellular redox homeostasis leading to increased ROS levels and a decrease in the mitochondrial membrane potential. ROS scavengers suppressed ROS formation and rescued cells from damage. On the molecular level, MC3 blocked the interaction of Trx with ASK1 and subsequently activated p38-associated signaling. Furthermore, inhibition of this pathway by using ASK1 siRNA or a p38 inhibitor clearly attenuated the effect of MC3 on cell proliferation in Panc1 and ASPC1. Conclusions: Our results confirm that MC3 is a TrxR inhibitor and show MC3 induced apoptosis in gemcitabine-resistant PDACs. MC3 mediated cell death could be blocked by using anti-oxidants, ASK1 siRNA or p38 inhibitor suggesting that the Trx-ASK1-p38 signal cascade played an important role in gold(I) NHC complexes-mediated cellular damage.
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a trxr inhibiting gold i nhc complex induces apoptosis through ask1 p38 mapk signaling in pancreatic cancer cells
Molecular Cancer, 2014Co-Authors: Xinlai Cheng, Palvo Holenya, Hamed Alborzinia, Riccardo Rubbiani, Suzan Can, Ingo Ott, Stefan WolflAbstract:Background: Cancer cells in the advanced stage show aberrant antioxidant capacity to detoxify excessive ROS resulting in the compensation for intrinsic oxidative stress and therapeutic resistance. PDAC is one of the most lethal cancers and often associated with a high accumulation of ROS. Recent studies identified gold(I) NHC complexes as potent TrxR inhibitors suppressing cell growth in a wide spectrum of human malignant cell lines at the low micromolar concentration. However, the mechanism of action is not completely elucidated yet. Methods: To understand the biological function of gold(I) NHC complexes in PDAC, we used a recently published gold(I) NHC complex, MC3, and evaluated its anti-proliferative effect in four PDAC cell lines, determined by MTT and SRB assays. In further detailed analysis, we analyzed cellular ROS levels using the ROS indicator DHE and mitochondrial membrane potential indicated by the dye JC-1 in Panc1. We also analyzed cell cycle arrest and apoptosis by FACS. To elucidate the role of specific cell signaling pathways in MC3-induced cell death, co-incubation with ROS scavengers, a p38-MAPK inhibitor and siRNA mediated depletion of ASK1 were performed, and results were analyzed by immunoblotting, ELISA-microarrays, qRT-PCR and immunoprecipitation. Results: Our data demonstrate that MC3 efficiently suppressed cell growth, and induced cell cycle arrest and apoptosis in pancreatic cancer cells, in particular in the gemcitabine-resistant cancer cells Panc1 and ASPC1. Treatment with MC3 resulted in a Substantial Alteration of the cellular redox homeostasis leading to increased ROS levels and a decrease in the mitochondrial membrane potential. ROS scavengers suppressed ROS formation and rescued cells from damage. On the molecular level, MC3 blocked the interaction of Trx with ASK1 and subsequently activated p38-associated signaling. Furthermore, inhibition of this pathway by using ASK1 siRNA or a p38 inhibitor clearly attenuated the effect of MC3 on cell proliferation in Panc1 and ASPC1. Conclusions: Our results confirm that MC3 is a TrxR inhibitor and show MC3 induced apoptosis in gemcitabine-resistant PDACs. MC3 mediated cell death could be blocked by using anti-oxidants, ASK1 siRNA or p38 inhibitor suggesting that the Trx-ASK1-p38 signal cascade played an important role in gold(I) NHC complexes-mediated cellular damage.
