scholarly journals HIF2α regulates the synthesis and release of epinephrine in the adrenal medulla

Author(s):  
Deepika Watts ◽  
Nicole Bechmann ◽  
Ana Meneses ◽  
Ioanna K. Poutakidou ◽  
Denise Kaden ◽  
...  

Abstract The adrenal gland and its hormones regulate numerous fundamental biological processes; however, the impact of hypoxia signaling on adrenal function remains poorly understood. Here, we reveal that deficiency of HIF (hypoxia inducible factors) prolyl hydroxylase domain protein-2 (PHD2) in the adrenal medulla of mice results in HIF2α-mediated reduction in phenylethanolamine N-methyltransferase (PNMT) expression, and consequent reduction in epinephrine synthesis. Simultaneous loss of PHD2 in renal erythropoietin (EPO)-producing cells (REPCs) stimulated HIF2α-driven EPO overproduction, excessive RBC formation (erythrocytosis), and systemic hypoglycemia, which is necessary and sufficient to enhance exocytosis of epinephrine from the adrenal medulla. Based on these results, we propose that the PHD2-HIF2α axis in the adrenal medulla regulates the synthesis of epinephrine, whereas in REPCs, it indirectly induces the release of this hormone. Our findings are also highly relevant to the testing of small molecule PHD inhibitors in phase III clinical trials for patients with renal anemia. Key messages HIF2α and not HIF1α modulates PNMT during epinephrine synthesis in chromaffin cells. The PHD2-HIF2α-EPO axis induces erythrocytosis and hypoglycemia. Reduced systemic glucose facilitates exocytosis of epinephrine from adrenal gland.

2020 ◽  
Author(s):  
Deepika Watts ◽  
Nicole Bechmann ◽  
Ana Meneses ◽  
Ioanna K. Poutakidou ◽  
Denise Kaden ◽  
...  

ABSTRACTThe adrenal gland and its hormones regulate numerous fundamental biological processes; however, the impact of hypoxia signalling on its function remains scarcely understood. Here, we reveal that deficiency of HIF (Hypoxia Inducible Factors) prolyl hydroxylase domain protein-2 (PHD2) in the adrenal medulla of mice results in HIF2α-mediated reduction in phenylethanolamine N-methyltransferase (PNMT) expression, and consequent reduction in epinephrine synthesis. Concomitant loss of PHD2 in renal erythropoietin (EPO) producing cells stimulated HIF2α-driven EPO overproduction, excessive RBC formation (erythrocytosis) and systemic hypoglycaemia. Using mouse lines displaying only EPO-induced erythrocytosis or anaemia, we show that hypo- or hyperglycaemia is necessary and sufficient to respectively enhance or reduce exocytosis of epinephrine from the adrenal gland. Based on these results, we propose that the PHD2-HIF2α axis in the adrenal medulla and beyond regulates both synthesis and release of catecholamines, especially epinephrine. Our findings are also of great significance in view of the small molecule PHD inhibitors being tested in phase III global clinical development trials for use in renal anaemia patients.


2016 ◽  
Vol 14 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Qiang Zhang ◽  
Boris Freidlin ◽  
Edward L Korn ◽  
Susan Halabi ◽  
Sumithra Mandrekar ◽  
...  

Background: Futility (inefficacy) interim monitoring is an important component in the conduct of phase III clinical trials, especially in life-threatening diseases. Desirable futility monitoring guidelines allow timely stopping if the new therapy is harmful or if it is unlikely to demonstrate to be sufficiently effective if the trial were to continue to its final analysis. There are a number of analytical approaches that are used to construct futility monitoring boundaries. The most common approaches are based on conditional power, sequential testing of the alternative hypothesis, or sequential confidence intervals. The resulting futility boundaries vary considerably with respect to the level of evidence required for recommending stopping the study. Purpose: We evaluate the performance of commonly used methods using event histories from completed phase III clinical trials of the Radiation Therapy Oncology Group, Cancer and Leukemia Group B, and North Central Cancer Treatment Group. Methods: We considered published superiority phase III trials with survival endpoints initiated after 1990. There are 52 studies available for this analysis from different disease sites. Total sample size and maximum number of events (statistical information) for each study were calculated using protocol-specified effect size, type I and type II error rates. In addition to the common futility approaches, we considered a recently proposed linear inefficacy boundary approach with an early harm look followed by several lack-of-efficacy analyses. For each futility approach, interim test statistics were generated for three schedules with different analysis frequency, and early stopping was recommended if the interim result crossed a futility stopping boundary. For trials not demonstrating superiority, the impact of each rule is summarized as savings on sample size, study duration, and information time scales. Results: For negative studies, our results show that the futility approaches based on testing the alternative hypothesis and repeated confidence interval rules yielded less savings (compared to the other two rules). These boundaries are too conservative, especially during the first half of the study (<50% of information). The conditional power rules are too aggressive during the second half of the study (>50% of information) and may stop a trial even when there is a clinically meaningful treatment effect. The linear inefficacy boundary with three or more interim analyses provided the best results. For positive studies, we demonstrated that none of the futility rules would have stopped the trials. Conclusion: The linear inefficacy boundary futility approach is attractive from statistical, clinical, and logistical standpoints in clinical trials evaluating new anti-cancer agents.


2012 ◽  
Vol 30 (27_suppl) ◽  
pp. 129-129
Author(s):  
Raman Tatla ◽  
Denis Landaverde ◽  
Charles Victor ◽  
David Miles ◽  
Sunil Verma

129 Background: The management of metastatic breast cancer (MBC) is often considered to be palliative, with most interventions intended to relieve disease symptoms, minimize treatment effects and prolong patient survival. The impact of disease and treatment on a patient's funcitonal abilities has led to an emphasis of incorporating quality of life (QoL) measures into clinical trials. The main objective of this study is to evaluate phase III clinical trials in MBC, and assess the inclusion of QOL as an endpoint, in addition to conventional efficacy endpoints. Methods: A structured PubMed search was conducted to identify phase III clinical trials published between Jan. 1990 and Aug. 2011, evaluating systemic treatment in MBC patients. Data pertaining to treatment regimens, study endpoints and clinical findings were collected, with a particular focus on progression-based (PB), overall survival (OS), and QoL endpoints. Results: Of 520 publications identified, 122 phase III MBC clinical trials met the inclusion criteria. Of these studies, 98.4% and 95.9% included PB and OS respectively, as clinical endpoints, while QoL was assessed in only 46 (37.7%) studies. While the inclusion of QoL was not associated with the significance of PB results, there was an association between the inclusion of QoL and OS results, with 59% of significant OS studies and 32% of non-significant OS studies including QoL as a clinical endpoint (p=0.016). When stratified by treatment arm, it was found that studies favouring standard therapy were more likely to include QoL (75%, p=0.045), compared to those favouring the intervention (56%), and those without significant differences (32%). Conclusions: Although the importance of QoL is often emphasized in MBC management and treatment decisions, only one-third of identified phase III clinical trials included an assessment of QoL. About half of these trials showed no statistically significant differences in the QoL endpoint; of not, instruments of varying validity were utilized. There needs to be a greater emphasis on the evaluation of QoL, with the use of standard and validated QoL tools in MBC clinical trials, especially as we increasingly focus on progression-based endpoints.


2019 ◽  
Vol 20 (16) ◽  
pp. 3847 ◽  
Author(s):  
Daniel Young ◽  
Nabangshu Das ◽  
Anthonia Anowai ◽  
Antoine Dufour

Matrix metalloproteinases (MMPs) have been studied in the context of cancer due to their ability to increase cell invasion, and were initially thought to facilitate metastasis solely through the degradation of the extracellular matrix (ECM). MMPs have also been investigated in the context of their ECM remodeling activity in several acute and chronic inflammatory diseases. However, after several MMP inhibitors failed in phase III clinical trials, a global reassessment of their biological functions was undertaken, which has revealed multiple unanticipated functions including the processing of chemokines, cytokines, and cell surface receptors. Despite what their name suggests, the matrix aspect of MMPs could contribute to a lesser part of their physiological functions in inflammatory diseases, as originally anticipated. Here, we present examples of MMP substrates implicated in cell signaling, independent of their ECM functions, and discuss the impact for the use of MMP inhibitors.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e16547-e16547
Author(s):  
Raman Tatla ◽  
Denis Landaverde ◽  
Charles Victor ◽  
David Miles ◽  
Sunil Verma

e16547 Background: The management of metastatic breast cancer (MBC) is often considered to be palliative, with therapy used to relieve disease symptoms, minimize treatment effects and prolong survival. The impact of disease and treatment on patients has led to an emphasis of quality of life (QoL) measures in clinical trials. This study’s primary objective is to evaluate phase III clinical trials in MBC, and assess the inclusion of QoL as an endpoint. Methods: A PubMed search was conducted to identify phase III clinical trials published from Jan 1990 to Aug 2011, which evaluated systemic therapy in MBC patients. Data pertaining to treatment regimens, study endpoints and clinical findings were collected, with a focus on progression-based (PB), overall survival (OS), and QoL endpoints. The instrument(s) used to evaluate QoL were also noted (if applicable). Results: Of 520 publications identified, 122 phase III MBC clinical trials met the inclusion criteria. Of these studies, 98.4% and 95.9% included PB and OS respectively, as clinical endpoints, while QoL was assessed in only 46 (37.7%) studies. 14 instruments were identified as QoL tools among the studies, with EORTC QLQ-C30 and FACT-B accounting for 54.7% of the instruments used. While the inclusion of QoL was not related to the significance of PB results, there was an association between the inclusion of QoL and OS results, with 59% of significant OS studies and 32% of non-significant OS studies including QoL as an endpoint (p=0.016). Stratification by treatment arm found that studies favouring standard therapy were more likely to include QoL (75%, p=0.045), compared to those favouring the intervention (56%), and those without significant differences (32%). Conclusions: Although the importance of QoL is often emphasized in MBC management, only one-third of identified phase III clinical trials included its assessment. Half of these trials showed no statistically significant differences in QoL endpoint; of note, instruments of varying validity were utilized. There needs to be greater emphasis on the evaluation of QoL, with the use of standard and validated QoL tools in MBC clinical trials, especially as we increasingly focus on progression-based endpoints.


2001 ◽  
Vol 120 (5) ◽  
pp. A284-A284
Author(s):  
B NAULT ◽  
S SUE ◽  
J HEGGLAND ◽  
S GOHARI ◽  
G LIGOZIO ◽  
...  

2001 ◽  
Vol 28 (6) ◽  
pp. 620-625 ◽  
Author(s):  
Pierre Falardeau ◽  
Pierre Champagne ◽  
Patrick Poyet ◽  
Claude Hariton ◽  
[Eacute]ric Dupont

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1073
Author(s):  
Juan-Carlos Saiz

West Nile virus (WNV) is a widely distributed enveloped flavivirus transmitted by mosquitoes, which main hosts are birds. The virus sporadically infects equids and humans with serious economic and health consequences, as infected individuals can develop a severe neuroinvasive disease that can even lead to death. Nowadays, no WNV-specific therapy is available and vaccines are only licensed for use in horses but not for humans. While several methodologies for WNV vaccine development have been successfully applied and have contributed to significantly reducing its incidence in horses in the US, none have progressed to phase III clinical trials in humans. This review addresses the status of WNV vaccines for horses, birds, and humans, summarizing and discussing the challenges they face for their clinical advance and their introduction to the market.


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