The Experts below are selected from a list of 7347 Experts worldwide ranked by ideXlab platform

Halina Offner - One of the best experts on this subject based on the ideXlab platform.

  • an orally bioavailable synthetic analog of an active dehydroepiandrosterone metabolite reduces established disease in rodent models of rheumatoid arthritis
    Journal of Pharmacology and Experimental Therapeutics, 2009
    Co-Authors: Halina Offner, Gary S Firestein, David L Boyle, Raymond Pieters, James M Frincke, Armando Garsd, Steven K White, Christopher L Reading, Dominick L Auci
    Abstract:

    Dehydroepiandrosterone (DHEA) treatment provides diverse anti-inflammatory benefits in rodent models of diseases, including rheumatoid arthritis (RA), but only limited benefits to patients. In rodents, DHEA is metabolized to (among others) androstene-3β,7β,17β-triol (AET), which retains potent anti-inflammatory activity. 17α-Ethynyl-5-androstene-3β,7β,17β-triol (HE3286) is a novel, metabolically stabilized, orally bioavailable derivative of AET. In the DBA Mouse model of collagen-induced arthritis (CIA), once-daily oral treatments (gavage) with HE3286 (40 mg/kg), beginning at onset of disease, significantly decreased disease. Benefit was associated with reduction in joint inflammation, erosion, and synovial proliferation as measured by histological analysis and mRNA of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and IL-23. Significant benefit was also observed in the CIA model even when treatments were delayed until 7 days after the onset of arthritis. Furthermore, dose-dependent benefit was observed in the DBA Mouse model of collagen antibody-induced arthritis, as well as reductions in IL-6 and matrix metalloproteinase-3 mRNA levels in joints at the peak of disease and at the end of the study. HE3286, in contrast to dexamethasone, was not immune-suppressive in several classic animal models of immune function. Instead, HE3286 treatment was associated with reduced nuclear factor-κB activation and in our previous studies, with increased regulatory T cells. We hypothesize that HE3286 may represent a novel, perhaps first-in-class, anti-inflammatory agent and may more fully translate the benefits of DHEA, heretofore largely limited to rodents, into treatments for human diseases, including autoimmune disorders such as RA.

  • a new orally bioavailable synthetic androstene inhibits collagen induced arthritis in the Mouse androstene hormones as regulators of regulatory t cells
    Annals of the New York Academy of Sciences, 2007
    Co-Authors: Dominick L Auci, James M Frincke, Christopher L Reading, Laurie J Kaler, Sandhya Subramanian, Yugin Huang, Halina Offner
    Abstract:

    Dehydroepiandrosterone (DHEA) has attracted much interest because of its many antiaging, metabolic and immune-modulating effects in rodents. Synthetic derivatives, such as 5-androstene-16alpha-fluoro-17-one (HE2500) and certain natural metabolites also provide benefit in various animal models of autoimmune and metabolic diseases. But, like DHEA, low potency and low oral bioavailability suggested limited usefulness of these compounds in humans. We hypothesized that HE3286, a novel 17-ethynyl derivative would be orally bioavailable, more potent, and chemically more useful in man than its parent compound. We found that on a dose/mass basis, HE3286 demonstrated up to 25% oral bioavailability in mice. In the DBA Mouse model of collagen-induced arthritis (CIA), animals receiving oral treatment with HE3286 (50 mg/kg), beginning at onset of disease, significantly decreased CIA peak scores and daily severity of arthritis scores. Benefit was associated with decreases in: (1) production of TNF-alpha, IL-6, and IL-17; and (2) decreases in joint inflammation, erosion, and synovial proliferation as judged by histological analysis. HE3286 was not found to be immune suppressive in any of the classical models tested, including mitogen-induced proliferation, delayed-type hypersensitivity, or mixed lymphocyte reaction. Instead, benefit was associated with increases in numbers and function of CD4+CD25+FOXp3+CD127- regulatory T cells (T reg). To our knowledge, this is probably the first study to report that an orally bioavailable synthetic analogue of DHEA can ameliorate ongoing disease in a CIA Mouse model with relevance to rheumatoid arthritis (RA) and to correlate that finding with decreases in proinflammatory cytokines and increases in T reg cells. Hormones targeting T reg cells hold the intriguing potential to treat autoimmune, infectious, and neoplastic diseases.

Dominick L Auci - One of the best experts on this subject based on the ideXlab platform.

  • an orally bioavailable synthetic analog of an active dehydroepiandrosterone metabolite reduces established disease in rodent models of rheumatoid arthritis
    Journal of Pharmacology and Experimental Therapeutics, 2009
    Co-Authors: Halina Offner, Gary S Firestein, David L Boyle, Raymond Pieters, James M Frincke, Armando Garsd, Steven K White, Christopher L Reading, Dominick L Auci
    Abstract:

    Dehydroepiandrosterone (DHEA) treatment provides diverse anti-inflammatory benefits in rodent models of diseases, including rheumatoid arthritis (RA), but only limited benefits to patients. In rodents, DHEA is metabolized to (among others) androstene-3β,7β,17β-triol (AET), which retains potent anti-inflammatory activity. 17α-Ethynyl-5-androstene-3β,7β,17β-triol (HE3286) is a novel, metabolically stabilized, orally bioavailable derivative of AET. In the DBA Mouse model of collagen-induced arthritis (CIA), once-daily oral treatments (gavage) with HE3286 (40 mg/kg), beginning at onset of disease, significantly decreased disease. Benefit was associated with reduction in joint inflammation, erosion, and synovial proliferation as measured by histological analysis and mRNA of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and IL-23. Significant benefit was also observed in the CIA model even when treatments were delayed until 7 days after the onset of arthritis. Furthermore, dose-dependent benefit was observed in the DBA Mouse model of collagen antibody-induced arthritis, as well as reductions in IL-6 and matrix metalloproteinase-3 mRNA levels in joints at the peak of disease and at the end of the study. HE3286, in contrast to dexamethasone, was not immune-suppressive in several classic animal models of immune function. Instead, HE3286 treatment was associated with reduced nuclear factor-κB activation and in our previous studies, with increased regulatory T cells. We hypothesize that HE3286 may represent a novel, perhaps first-in-class, anti-inflammatory agent and may more fully translate the benefits of DHEA, heretofore largely limited to rodents, into treatments for human diseases, including autoimmune disorders such as RA.

  • a new orally bioavailable synthetic androstene inhibits collagen induced arthritis in the Mouse androstene hormones as regulators of regulatory t cells
    Annals of the New York Academy of Sciences, 2007
    Co-Authors: Dominick L Auci, James M Frincke, Christopher L Reading, Laurie J Kaler, Sandhya Subramanian, Yugin Huang, Halina Offner
    Abstract:

    Dehydroepiandrosterone (DHEA) has attracted much interest because of its many antiaging, metabolic and immune-modulating effects in rodents. Synthetic derivatives, such as 5-androstene-16alpha-fluoro-17-one (HE2500) and certain natural metabolites also provide benefit in various animal models of autoimmune and metabolic diseases. But, like DHEA, low potency and low oral bioavailability suggested limited usefulness of these compounds in humans. We hypothesized that HE3286, a novel 17-ethynyl derivative would be orally bioavailable, more potent, and chemically more useful in man than its parent compound. We found that on a dose/mass basis, HE3286 demonstrated up to 25% oral bioavailability in mice. In the DBA Mouse model of collagen-induced arthritis (CIA), animals receiving oral treatment with HE3286 (50 mg/kg), beginning at onset of disease, significantly decreased CIA peak scores and daily severity of arthritis scores. Benefit was associated with decreases in: (1) production of TNF-alpha, IL-6, and IL-17; and (2) decreases in joint inflammation, erosion, and synovial proliferation as judged by histological analysis. HE3286 was not found to be immune suppressive in any of the classical models tested, including mitogen-induced proliferation, delayed-type hypersensitivity, or mixed lymphocyte reaction. Instead, benefit was associated with increases in numbers and function of CD4+CD25+FOXp3+CD127- regulatory T cells (T reg). To our knowledge, this is probably the first study to report that an orally bioavailable synthetic analogue of DHEA can ameliorate ongoing disease in a CIA Mouse model with relevance to rheumatoid arthritis (RA) and to correlate that finding with decreases in proinflammatory cytokines and increases in T reg cells. Hormones targeting T reg cells hold the intriguing potential to treat autoimmune, infectious, and neoplastic diseases.

Christopher L Reading - One of the best experts on this subject based on the ideXlab platform.

  • an orally bioavailable synthetic analog of an active dehydroepiandrosterone metabolite reduces established disease in rodent models of rheumatoid arthritis
    Journal of Pharmacology and Experimental Therapeutics, 2009
    Co-Authors: Halina Offner, Gary S Firestein, David L Boyle, Raymond Pieters, James M Frincke, Armando Garsd, Steven K White, Christopher L Reading, Dominick L Auci
    Abstract:

    Dehydroepiandrosterone (DHEA) treatment provides diverse anti-inflammatory benefits in rodent models of diseases, including rheumatoid arthritis (RA), but only limited benefits to patients. In rodents, DHEA is metabolized to (among others) androstene-3β,7β,17β-triol (AET), which retains potent anti-inflammatory activity. 17α-Ethynyl-5-androstene-3β,7β,17β-triol (HE3286) is a novel, metabolically stabilized, orally bioavailable derivative of AET. In the DBA Mouse model of collagen-induced arthritis (CIA), once-daily oral treatments (gavage) with HE3286 (40 mg/kg), beginning at onset of disease, significantly decreased disease. Benefit was associated with reduction in joint inflammation, erosion, and synovial proliferation as measured by histological analysis and mRNA of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and IL-23. Significant benefit was also observed in the CIA model even when treatments were delayed until 7 days after the onset of arthritis. Furthermore, dose-dependent benefit was observed in the DBA Mouse model of collagen antibody-induced arthritis, as well as reductions in IL-6 and matrix metalloproteinase-3 mRNA levels in joints at the peak of disease and at the end of the study. HE3286, in contrast to dexamethasone, was not immune-suppressive in several classic animal models of immune function. Instead, HE3286 treatment was associated with reduced nuclear factor-κB activation and in our previous studies, with increased regulatory T cells. We hypothesize that HE3286 may represent a novel, perhaps first-in-class, anti-inflammatory agent and may more fully translate the benefits of DHEA, heretofore largely limited to rodents, into treatments for human diseases, including autoimmune disorders such as RA.

  • a new orally bioavailable synthetic androstene inhibits collagen induced arthritis in the Mouse androstene hormones as regulators of regulatory t cells
    Annals of the New York Academy of Sciences, 2007
    Co-Authors: Dominick L Auci, James M Frincke, Christopher L Reading, Laurie J Kaler, Sandhya Subramanian, Yugin Huang, Halina Offner
    Abstract:

    Dehydroepiandrosterone (DHEA) has attracted much interest because of its many antiaging, metabolic and immune-modulating effects in rodents. Synthetic derivatives, such as 5-androstene-16alpha-fluoro-17-one (HE2500) and certain natural metabolites also provide benefit in various animal models of autoimmune and metabolic diseases. But, like DHEA, low potency and low oral bioavailability suggested limited usefulness of these compounds in humans. We hypothesized that HE3286, a novel 17-ethynyl derivative would be orally bioavailable, more potent, and chemically more useful in man than its parent compound. We found that on a dose/mass basis, HE3286 demonstrated up to 25% oral bioavailability in mice. In the DBA Mouse model of collagen-induced arthritis (CIA), animals receiving oral treatment with HE3286 (50 mg/kg), beginning at onset of disease, significantly decreased CIA peak scores and daily severity of arthritis scores. Benefit was associated with decreases in: (1) production of TNF-alpha, IL-6, and IL-17; and (2) decreases in joint inflammation, erosion, and synovial proliferation as judged by histological analysis. HE3286 was not found to be immune suppressive in any of the classical models tested, including mitogen-induced proliferation, delayed-type hypersensitivity, or mixed lymphocyte reaction. Instead, benefit was associated with increases in numbers and function of CD4+CD25+FOXp3+CD127- regulatory T cells (T reg). To our knowledge, this is probably the first study to report that an orally bioavailable synthetic analogue of DHEA can ameliorate ongoing disease in a CIA Mouse model with relevance to rheumatoid arthritis (RA) and to correlate that finding with decreases in proinflammatory cytokines and increases in T reg cells. Hormones targeting T reg cells hold the intriguing potential to treat autoimmune, infectious, and neoplastic diseases.

James M Frincke - One of the best experts on this subject based on the ideXlab platform.

  • an orally bioavailable synthetic analog of an active dehydroepiandrosterone metabolite reduces established disease in rodent models of rheumatoid arthritis
    Journal of Pharmacology and Experimental Therapeutics, 2009
    Co-Authors: Halina Offner, Gary S Firestein, David L Boyle, Raymond Pieters, James M Frincke, Armando Garsd, Steven K White, Christopher L Reading, Dominick L Auci
    Abstract:

    Dehydroepiandrosterone (DHEA) treatment provides diverse anti-inflammatory benefits in rodent models of diseases, including rheumatoid arthritis (RA), but only limited benefits to patients. In rodents, DHEA is metabolized to (among others) androstene-3β,7β,17β-triol (AET), which retains potent anti-inflammatory activity. 17α-Ethynyl-5-androstene-3β,7β,17β-triol (HE3286) is a novel, metabolically stabilized, orally bioavailable derivative of AET. In the DBA Mouse model of collagen-induced arthritis (CIA), once-daily oral treatments (gavage) with HE3286 (40 mg/kg), beginning at onset of disease, significantly decreased disease. Benefit was associated with reduction in joint inflammation, erosion, and synovial proliferation as measured by histological analysis and mRNA of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and IL-23. Significant benefit was also observed in the CIA model even when treatments were delayed until 7 days after the onset of arthritis. Furthermore, dose-dependent benefit was observed in the DBA Mouse model of collagen antibody-induced arthritis, as well as reductions in IL-6 and matrix metalloproteinase-3 mRNA levels in joints at the peak of disease and at the end of the study. HE3286, in contrast to dexamethasone, was not immune-suppressive in several classic animal models of immune function. Instead, HE3286 treatment was associated with reduced nuclear factor-κB activation and in our previous studies, with increased regulatory T cells. We hypothesize that HE3286 may represent a novel, perhaps first-in-class, anti-inflammatory agent and may more fully translate the benefits of DHEA, heretofore largely limited to rodents, into treatments for human diseases, including autoimmune disorders such as RA.

  • a new orally bioavailable synthetic androstene inhibits collagen induced arthritis in the Mouse androstene hormones as regulators of regulatory t cells
    Annals of the New York Academy of Sciences, 2007
    Co-Authors: Dominick L Auci, James M Frincke, Christopher L Reading, Laurie J Kaler, Sandhya Subramanian, Yugin Huang, Halina Offner
    Abstract:

    Dehydroepiandrosterone (DHEA) has attracted much interest because of its many antiaging, metabolic and immune-modulating effects in rodents. Synthetic derivatives, such as 5-androstene-16alpha-fluoro-17-one (HE2500) and certain natural metabolites also provide benefit in various animal models of autoimmune and metabolic diseases. But, like DHEA, low potency and low oral bioavailability suggested limited usefulness of these compounds in humans. We hypothesized that HE3286, a novel 17-ethynyl derivative would be orally bioavailable, more potent, and chemically more useful in man than its parent compound. We found that on a dose/mass basis, HE3286 demonstrated up to 25% oral bioavailability in mice. In the DBA Mouse model of collagen-induced arthritis (CIA), animals receiving oral treatment with HE3286 (50 mg/kg), beginning at onset of disease, significantly decreased CIA peak scores and daily severity of arthritis scores. Benefit was associated with decreases in: (1) production of TNF-alpha, IL-6, and IL-17; and (2) decreases in joint inflammation, erosion, and synovial proliferation as judged by histological analysis. HE3286 was not found to be immune suppressive in any of the classical models tested, including mitogen-induced proliferation, delayed-type hypersensitivity, or mixed lymphocyte reaction. Instead, benefit was associated with increases in numbers and function of CD4+CD25+FOXp3+CD127- regulatory T cells (T reg). To our knowledge, this is probably the first study to report that an orally bioavailable synthetic analogue of DHEA can ameliorate ongoing disease in a CIA Mouse model with relevance to rheumatoid arthritis (RA) and to correlate that finding with decreases in proinflammatory cytokines and increases in T reg cells. Hormones targeting T reg cells hold the intriguing potential to treat autoimmune, infectious, and neoplastic diseases.

Lesa L Aylward - One of the best experts on this subject based on the ideXlab platform.

  • human response to dioxin aryl hydrocarbon receptor ahr molecular structure function and dose response data for enzyme induction indicate an impaired human ahr
    Journal of Toxicology and Environmental Health-part B-critical Reviews, 2006
    Co-Authors: Kevin T Connor, Lesa L Aylward
    Abstract:

    The aryl hydrocarbon receptor (AhR) mediates nearly all studied adverse effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and many related compounds. Binding of TCDD or related ligands to AhR is the key initiating event in downstream biochemical responses. The binding affinity of AhR for TCDD is specific to species and strain, and studies of human AhR demonstrate binding affinities approximately an order of magnitude or more lower than those observed in the most sensitive laboratory strains and species. Molecular genetic studies confirmed that human AhR shares key mutations with the DBA Mouse strain that result in an "impaired" AhR (with respect to TCDD binding and responsiveness). Despite a number of polymorphisms in human AhR, the key "DBA-type" mutations appear to be a constant feature of the human AhR, and no polymorphisms have been identified that compensate for the impaired binding function conferred by these mutations. Consistent with the impaired binding status of the human AhR, human cells have consistently required approximately 10-fold higher concentrations of TCDD in vitro than rodent cells to respond with enzyme induction. Recent studies of in vivo enzyme induction-related endpoints in human populations with moderately and highly increased TCDD body burdens detected no relationship between these endpoints and TCDD body burdens at body-burden levels up to 250 ng TEQ/kg body weight, or approximately 25 times above the upper range of current general population background body burdens, while marked elevations in enzyme activity were observed in persons with body burdens above 750 ng TEQ/kg. In contrast, the more sensitive laboratory rodent strains and species exposed to TCDD exhibit significant enzyme induction at body burdens below 50 ng/kg. These interspecies data on the most sensitive and best understood response to binding of TCDD and related compounds to the AhR are consistent with the binding affinity and molecular structure data and support the hypothesis that the human AhR is less functional than the AhR of the more sensitive laboratory animals at a molecular level. Quantitative risk assessments involving interspecies extrapolation from sensitive laboratory species and strains should take these fundamental differences into account when margins of exposure and safety factors are considered.