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- Carlsson, Stina K., 1982-
(författare)
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Effects of adenosine and acetylcholine on the lacrimal gland
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A balanced tear film is essential for a healthy ocular surface. Insufficient tear production may result in dry eye, a common disorder in the elderly population. Dry eye causes significant discomfort in the patients and may lead to visual impairment and ocular infections. The lacrimal gland secretes water, proteins and electrolytes to the aqueous layer of the tear film. Lacrimal gland secretion is tightly regulated by e.g. neuronally released acetylcholine. The effect of acetylcholine on lacrimal gland secretion was recently found to be potentiated by adenosine. Adenosine is an important signaling molecule acting upon the adenosine receptors: A1, A2A, A2B and A3.The aim of this thesis was to study effects of adenosine and acetylcholine on intracellular signaling pathways and lacrimal gland secretion. Cholinergic stimulation of secretion was shown to be regulated by the mitogen activated protein kinase p38, a protein previously not known to be involved in exocrine secretion. p38 was activated in response to cholinergic stimulation and inhibition of p38 significantly diminished cholinergic secretion.When investigating adenosine effects, potentiation of cholinergic secretion was observed by activation of the A2B receptor in addition to the previously studied A1 receptor. An A2 receptor agonist increased cholinergic rabbit lacrimal gland protein secretion at several concentrations. The increase was inhibited by antagonism of the A2B receptor, but not the A2A receptor. When investigating the intracellular signaling pathways following adenosine and acetylcholine receptor activation, adenosine was shown to increase of cAMP levels. An additional increase in cAMP levels was observed after parallel adenosine and cholinergic receptor activation. Inhibition of Ca2+ release from the endoplasmic reticulum had inhibitory effects of cholinergic stimulation of secretion. In addition, the expression of adenosine receptors in a mouse model of autoimmune dry eye was investigated. The results showed a lymphocyte dependent upregulation of A2A receptors in diseased mice compared to controls.In conclusion, the results in this thesis provide significant contributions in the search of dry eye therapeutics through studies of adenosine and acetylcholine receptor activation.
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- Welén, Karin, 1970, et al.
(författare)
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A Phase 2 Trial of the Effect of Antiandrogen Therapy on COVID-19 Outcome : No Evidence of Benefit, Supported by Epidemiology and In Vitro Data
- 2022
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Ingår i: European Urology. - : Elsevier. - 0302-2838 .- 1873-7560. ; 81:3, s. 285-293
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Tidskriftsartikel (refereegranskat)abstract
- Background: Men are more severely affected by COVID-19. Testosterone may influence SARS-CoV-2 infection and the immune response.Objective: To clinically, epidemiologically, and experimentally evaluate the effect of antiandrogens on SARS-CoV-2 infection.Designs, settings, and participants: A randomized phase 2 clinical trial (COVIDENZA) enrolled 42 hospitalized COVID-19 patients before safety evaluation. We also conducted a population-based retrospective study of 7894 SARS-CoV-2–positive prostate cancer patients and an experimental study using an air-liquid interface three-dimensional culture model of primary lung cells.Intervention: In COVIDENZA, patients were randomized 2:1 to 5 d of enzalutamide or standard of care.Outcome measurements: The primary outcomes in COVIDENZA were the time to mechanical ventilation or discharge from hospital. The population-based study investigated risk of hospitalization, intensive care, and death from COVID-19 after androgen inhibition.Results and limitations: Enzalutamide-treated patients required longer hospitalization (hazard ratio [HR] for discharge from hospital 0.43, 95% confidence interval [CI] 0.20–0.93) and the trial was terminated early. In the epidemiological study, no preventive effects were observed. The frail population of patients treated with androgen deprivation therapy (ADT) in combination with abiraterone acetate or enzalutamide had a higher risk of dying from COVID-19 (HR 2.51, 95% CI 1.52–4.16). In vitro data showed no effect of enzalutamide on virus replication. The epidemiological study has limitations that include residual confounders.Conclusions: The results do not support a therapeutic effect of enzalutamide or preventive effects of bicalutamide or ADT in COVID-19. Thus, these antiandrogens should not be used for hospitalized COVID-19 patients or as prevention for COVID-19. Further research on these therapeutics in this setting are not warranted.Patient summary: We studied whether inhibition of testosterone could diminish COVID-19 symptoms. We found no evidence of an effect in a clinical study or in epidemiological or experimental investigations. We conclude that androgen inhibition should not be used for prevention or treatment of COVID-19.
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