In the second C4 article, contributors examine five issues, including timely access during the hospital discharge process, access to immunosuppressive medications for life after transplant, access to ...medications used for off‐label indications, access to drugs affected by drug shortages, and the patient perspective.
► Differential affinity of P450 reductase (CYPOR) mutants to heme oxygenase-1. ► Regulation of HO-1 oligomerization by CYPOR in
in vitro reconstituted system. ► Inhibition of HO-1 activity at greater ...than 2:1 ratios of CYPOR to HO-1. ► Disruption of HO-1 oligomerization in HEK293 cells by CYPOR.
Genetic variations in
POR, encoding NADPH-cytochrome P450 oxidoreductase (CYPOR), can diminish the function of numerous cytochromes P450, and also have the potential to block degradation of heme by heme oxygenase-1 (HO-1). Purified full-length human CYPOR, HO-1, and biliverdin reductase were reconstituted in lipid vesicles and assayed for NADPH-dependent conversion of heme to bilirubin. Naturally-occurring human CYPOR variants queried were: WT, A115V, Y181D, P228L, M263V, A287P, R457H, Y459H, and V492E. All CYPOR variants exhibited decreased bilirubin production relative to WT, with a lower apparent affinity of the CYPOR–HO-1 complex than WT. Addition of FMN or FAD partially restored the activities of Y181D, Y459H, and V492E. When mixed with WT CYPOR, only the Y181D CYPOR variant inhibited heme degradation by sequestering HO-1, whereas Y459H and V492E were unable to inhibit HO-1 activity suggesting that CYPOR variants might have differential binding affinities with redox partners. Titrating the CYPOR–HO-1 complex revealed that the optimal CYPOR:HO-1 ratio for activity was 1:2, lending evidence in support of productive HO-1 oligomerization, with higher ratios of CYPOR:HO-1 showing decreased activity. In conclusion, human
POR mutations, shown to impact P450 activities, also result in varying degrees of diminished HO-1 activity, which may further complicate CYPOR deficiency.
Solanezumab in‐depth outcomes Farlow, Martin R.; Bateman, Randall J.; Aschenbrenner, Andrew J. ...
Alzheimer's & dementia,
December 2020, Letnik:
16
Journal Article
Recenzirano
Odprti dostop
Background
Solanezumab is a monoclonal antibody targeting soluble forms of β‐amyloid protein important in the pathogenesis of Alzheimer’s disease (AD). Three previous 18‐month double‐blind ...placebo‐controlled trials of low‐dose solanezumab in late‐onset sporadic AD found inconsistent benefits on cognitive and functional assessments. Dominantly‐inherited mutation‐associated AD subjects both before and after onset of symptoms form an ideal population to study potential benefits of solanezumab therapy.
Method
Mutation‐carrying asymptomatic (CDR 0, N=41) or mildly symptomatic (CDR 0.5 – 1, N=28) patients were treated for a minimum of 4 years and up to 7 years in a double‐blind 3 to 1 active versus placebo randomized clinical trial that measured disease progression by clinical, neuropsychological and biomarker evaluations. The trial was initiated with a dose of 400 mg every 4 weeks and escalated to 1600 mg when low dose trials in sporadic AD did not meet their primary endpoints. The primary cognitive outcome measure was DIAN‐MCE, composed of Delayed Recall Score of the International Shopping List Test, the Delayed Recall score of the Logical Memory IIa subtest from the Wechsler Memory Scale‐Revised, the Digit Symbol Substitution Test total score from the WAIS‐R and the MMSE total score. Secondary outcomes included a battery of other cognitive and functional measures. The study was powered to detect delay of cognitive disease progression in the DIAN‐MCE. Biomarkers include imaging modalities (volumetric MRI, FDG, amyloid and Tau PET). CSF markers included β‐amyloid, Tau and PhosphoTau species. NfL was measured in both CSF and plasma. The study used a pre‐specified Bayesian multivariate disease progression model, which included dynamic borrowing of control subjects from the DIAN Observational study.
Result
The topline efficacy, safety and biomarker results will be reported.
Conclusion
This study provides the first test of targeting soluble abeta forms in DIAD. It addresses the efficacy of early initiation of higher doses of solanezumab targeting soluble forms of amyloid as a disease modifying therapy. While these results are specific to DIAD, they have the potential to inform the application of anti‐amyloid therapy in sporadic AD.
Background
Alzheimer’s disease (AD) prevention trials aim to intervene prior to significant neuronal loss, brain damage, and symptom onset to delay or slow cognitive decline. In dominantly inherited ...AD (DIAD), mutation carriers develop symptomatic AD at predictable ages with near 100% penetrance. In 2012, the Dominantly Inherited Alzheimer Network Trials Unit Adaptive Prevention Trial (DIAN‐TU APT) platform launched a double‐blind, randomized, placebo‐controlled, parallel group trial of two anti‐amyloid‐beta monoclonal antibodies with two different antigenic targets, gantenerumab and solanezumab (NCT01760005). The DIAN‐TU scientific development, implementation of the first AD prevention trial, trial challenges and opportunities, including dose escalation, and top‐line results will be presented.
Method
DIAN was established in 2008 in response to a call from the National Institute of Aging to establish a network to study DIAD and enable future clinical trials. Successive breakthroughs in understanding disease processes enabled the launch of the DIAN‐TU adaptive prevention trial, a global adaptive platform trial supporting testing multiple drugs in parallel. The DIAN‐TU partners include patients and families at risk for DIAD, global academic researchers, the NIH, Alzheimer’s Association, philanthropic supporters, the DIAN‐TU Pharma Consortium, and pharmaceutical companies with drugs being tested. Important milestones include developing a platform to enable a comprehensive efficient treatment trial for this rare population, adding tau PET as part of AMP AD, adapting dosing mid‐trial and extending the original biomarker trial to continue randomized dosing to test a cognitive endpoint until the last patient reaches 4 years, developing a disease progression statistical model and inclusion of DIAN observational data to increase the power to determine drug effects.
Result
The primary and key secondary outcomes of the DIAN‐TU trial will be presented for each therapy in the context of targeting amyloid‐beta at pre‐clinical and clinically symptomatic stages of disease.
Conclusion
These results inform about AD hypotheses, timing of treatment and the prospect of slowing, or preventing AD in DIAD and sporadic AD.
Abstract
Background
Alzheimer’s disease (AD) prevention trials aim to intervene prior to significant neuronal loss, brain damage, and symptom onset to delay or slow cognitive decline. In dominantly ...inherited AD (DIAD), mutation carriers develop symptomatic AD at predictable ages with near 100% penetrance. In 2012, the Dominantly Inherited Alzheimer Network Trials Unit Adaptive Prevention Trial (DIAN‐TU APT) platform launched a double‐blind, randomized, placebo‐controlled, parallel group trial of two anti‐amyloid‐beta monoclonal antibodies with two different antigenic targets, gantenerumab and solanezumab (NCT01760005). The DIAN‐TU scientific development, implementation of the first AD prevention trial, trial challenges and opportunities, including dose escalation, and top‐line results will be presented.
Method
DIAN was established in 2008 in response to a call from the National Institute of Aging to establish a network to study DIAD and enable future clinical trials. Successive breakthroughs in understanding disease processes enabled the launch of the DIAN‐TU adaptive prevention trial, a global adaptive platform trial supporting testing multiple drugs in parallel. The DIAN‐TU partners include patients and families at risk for DIAD, global academic researchers, the NIH, Alzheimer’s Association, philanthropic supporters, the DIAN‐TU Pharma Consortium, and pharmaceutical companies with drugs being tested. Important milestones include developing a platform to enable a comprehensive efficient treatment trial for this rare population, adding tau PET as part of AMP AD, adapting dosing mid‐trial and extending the original biomarker trial to continue randomized dosing to test a cognitive endpoint until the last patient reaches 4 years, developing a disease progression statistical model and inclusion of DIAN observational data to increase the power to determine drug effects.
Result
The primary and key secondary outcomes of the DIAN‐TU trial will be presented for each therapy in the context of targeting amyloid‐beta at pre‐clinical and clinically symptomatic stages of disease.
Conclusion
These results inform about AD hypotheses, timing of treatment and the prospect of slowing, or preventing AD in DIAD and sporadic AD.
Solanezumab in‐depth outcomes Farlow, Martin R.; Bateman, Randall J.; Aschenbrenner, Andrew J. ...
Alzheimer's & dementia,
12/2020, Letnik:
16, Številka:
S9
Journal Article
Recenzirano
Abstract
Background
Solanezumab is a monoclonal antibody targeting soluble forms of β‐amyloid protein important in the pathogenesis of Alzheimer’s disease (AD). Three previous 18‐month double‐blind ...placebo‐controlled trials of low‐dose solanezumab in late‐onset sporadic AD found inconsistent benefits on cognitive and functional assessments. Dominantly‐inherited mutation‐associated AD subjects both before and after onset of symptoms form an ideal population to study potential benefits of solanezumab therapy.
Method
Mutation‐carrying asymptomatic (CDR 0, N=41) or mildly symptomatic (CDR 0.5 – 1, N=28) patients were treated for a minimum of 4 years and up to 7 years in a double‐blind 3 to 1 active versus placebo randomized clinical trial that measured disease progression by clinical, neuropsychological and biomarker evaluations. The trial was initiated with a dose of 400 mg every 4 weeks and escalated to 1600 mg when low dose trials in sporadic AD did not meet their primary endpoints. The primary cognitive outcome measure was DIAN‐MCE, composed of Delayed Recall Score of the International Shopping List Test, the Delayed Recall score of the Logical Memory IIa subtest from the Wechsler Memory Scale‐Revised, the Digit Symbol Substitution Test total score from the WAIS‐R and the MMSE total score. Secondary outcomes included a battery of other cognitive and functional measures. The study was powered to detect delay of cognitive disease progression in the DIAN‐MCE. Biomarkers include imaging modalities (volumetric MRI, FDG, amyloid and Tau PET). CSF markers included β‐amyloid, Tau and PhosphoTau species. NfL was measured in both CSF and plasma. The study used a pre‐specified Bayesian multivariate disease progression model, which included dynamic borrowing of control subjects from the DIAN Observational study.
Result
The topline efficacy, safety and biomarker results will be reported.
Conclusion
This study provides the first test of targeting soluble abeta forms in DIAD. It addresses the efficacy of early initiation of higher doses of solanezumab targeting soluble forms of amyloid as a disease modifying therapy. While these results are specific to DIAD, they have the potential to inform the application of anti‐amyloid therapy in sporadic AD.
The endometrium contains a distinct population of immune cells that undergo cyclic changes during the menstrual cycle and implantation. The majority of these leucocytes are uterine NK (uNK) cells, ...however how these cells interact with uterine stromal fibroblasts remains unclear. We therefore investigated the paracrine effect of medium conditioned by uterine decidual leucocytes (which are enriched for uNK cells) on the gene expression profile of endometrial stromal fibroblasts in vitro using a cDNA microarray. Our results, verified by real-time PCR, ELISA and FACS analysis, reveal that soluble factors from uterine leucocytes substantially alter endometrial stromal fibroblast gene expression. The largest group of up-regulated genes found was chemokines and cytokines. These include IL-8, CCL8 and CXCL1, which have also been shown to be stimulated by contact of stromal fibroblasts with trophoblast, suggesting that uNK cells work synergistically to support trophoblast migration during implantation. The decidual leucocytes also up-regulated IL-15 and IL-15Rα in stromal fibroblasts which could produce a niche for uNK cells allowing proliferation within and recruitment into the uterus, as seen in bone marrow. Overall this study demonstrates, for the first time, the paracrine communication between uterine leucocytes and uterine stromal fibroblasts, and adds to the understanding of how the uterine immune system contributes to the changes seen within the cycling endometrium.
: To study amyloid β‐protein (Aβ) production and aggregation in vivo, we created two transgenic (Tg) mouse lines expressing the C‐terminal 100 amino acids of human amyloid precursor protein (APP): Tg ...C100.V717F and Tg C100.WT. Western blot analysis showed that human APP‐C100 and Aβ were produced in brain and some peripheral tissues and Aβ was produced in serum. Using antibodies specific for the Aβ C terminus we found that Tg C100.V717F produced a 1.6‐fold increase in Aβ42/Aβ40 compared with Tg C100.WT. Approximately 30% of total brain Aβ (∼122 ng/g of wet tissue) was water‐soluble. The remaining 70% of Aβ partitioned into the particulate fraction and was completely sodium dodecyl sulfate‐soluble. In contrast, human Alzheimer's disease brain has predominantly sodium dodecyl sulfate‐insoluble Aβ. Immunohistochemistry with an Aβ(5‐8) antibody showed that Aβ or Aβ‐containing fragments accumulated intracellularly in the hippocampus of aged Tg C100.V717F mice. The soluble Aβ levels in Tg brain are similar to those in normal human brain, and this may explain the lack of microscopic amyloid deposits in the Tg mice. However, this mouse model provides a system to study the intracellular processing and accumulation of Aβ or Aβ‐containing fragments and to screen for compounds directed at the γ‐secretase activity.
Genetic variations in
POR
, encoding NADPH-cytochrome P450 oxidoreductase (CYPOR), can diminish the function of numerous cytochromes P450, and also have the potential to block degradation of heme by ...heme oxygenase-I (HO-1). Purified full-length human CYPOR, HO-1, and biliverdin reductase were reconstituted in lipid vesicles and assayed for NADPH-dependent conversion of heme to bilirubin. Naturally-occurring human CYPOR variants queried were: WT, A115V, Y181D, P228L, M263V, A287P, R457H, Y459H, and V492E. All CYPOR variants exhibited decreased bilirubin production relative to WT, with a lower apparent affinity of the CYPOR∙HO-1 complex than WT. Addition of FMN or FAD partially restored the activities of Y181D, Y459H, and V492E. When mixed with WT CYPOR, only the Y181D CYPOR variant inhibited heme degradation by sequestering HO-1, whereas Y459H and V492E were unable to inhibit HO-1 activity suggesting that CYPOR variants might have differential binding affinities with redox partners. Titrating the CYPOR-HO-1 complex revealed that the optimal CYPOR:HO-1 ratio for activity was 1:2, lending evidence in support of productive HO-1 oligomerization, with higher ratios of CYPOR:HO-1 showing decreased activity. In conclusion, human
POR
mutations, shown to impact P450 activities, also result in varying degrees of diminished HO-1 activity, which may further complicate CYPOR deficiency.
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