Analytical challenges for measuring steroid responses to stress, neurodegeneration and injury in the central nervous system

Schumacher, Michaël; Guennoun, Rachida; Mattern, Claudia; Oudinet, Jean–Paul; Labombarda, Florencia; Nicola, Alejandro F. De; Lière, Philippe

doi:10.1016/j.steroids.2015.08.013

Cited by 38 publications

(17 citation statements)

References 242 publications

(306 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Nervous tissue, however, is a site of steroid production in vertebrates (e.g., Schlinger and Arnold 1991;Schumacher et al 2015), and a previous report showed that genes encoding two of the cytochrome P450 enzymes used for ecdysteroid synthesis are expressed in the worker honey bee brain (Yamazaki et al 2011). In a subgroup of subjects from Experiment 1 in which hemolymph, ovaries, and brains were sampled from the same individuals, hemolymph ecdysteroids were significantly (p < 0.01) elevated in QMP+ conditions (115.3 ± 39.9 pg/μL, n = 27) compared with QMP− conditions (17.7 ± 5.8 pg/μL, n = 28).…”

Section: Resultsmentioning

confidence: 99%

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Trawinski

Fahrbach

2018

Apidologie

View full text Add to dashboard Cite

-To test the hypothesis that exposure to queen mandibular pheromone (QMP) modulates ecdysteroid production in adult worker honey bees, ecdysteroids were measured in hemolymph and other tissues of individual adult worker honey bees reared with or without QMP in cages and field colonies. Ecdysteroid titers were higher in caged workers exposed to QMP continuously from the first day of adult life than in workers reared without QMP. Statistical cluster analysis suggested the possibility that a subgroup of workers (Bresponders^) is more sensitive to QMP in this regard than other workers. In 12-day-old workers, ecdysteroid titers in workers reared in queenright (QR) colonies were similar to those observed in cages with QMP, but lower than those in queenless (QL) colonies. Differences in number of ovarioles or degree of ovarian activation did not correlate with hemolymph ecdysteroids. Previous studies have demonstrated ecdysteroids in hemolymph in very young adult workers and in workers in QL colonies; the present study indicates that production of ecdysteroids occurs in older adult worker honey bees in the absence of morphological signs of ovarian activation, with cage studies revealing a modulatory role for QMP masked in the complex environment of the hive.ecdysteroids / ovary / queen mandibular pheromone / queenless / queenright

show abstract

Section: Resultsmentioning

confidence: 99%

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Trawinski

Fahrbach

2018

Apidologie

View full text Add to dashboard Cite

show abstract

“…For example, oestradiol (E 2 ) can not only be synthesised by the female ovary, but can also be derived from testosterone produced by the testes and aromatised in specific brain loci under the catalytic action of the aromatase enzyme . These steroids are usually called neuroactive steroids and directly act on neural cells either via membrane or nuclear signalling mechanisms …”

Section: Introductionmentioning

confidence: 99%

Steroid profiles in quail brain and serum: Sex and regional differences and effects of castration with steroid replacement

Lière

Cornil

Bournonville

et al. 2019

J Neuroendocrinology

Self Cite

View full text Add to dashboard Cite

Both systemic and local production contribute to the concentration of steroids measured in the brain. This idea was originally based on rodent studies and was later extended to other species, including humans and birds. In quail, a widely used model in behavioural neuroendocrinology, it was demonstrated that all enzymes needed to produce sex steroids from cholesterol are expressed and active in the brain, although the actual concentrations of steroids produced were never investigated. We carried out a steroid profiling in multiple brain regions and serum of sexually mature male and female quail by gas chromatography coupled with mass spectrometry. The concentrations of some steroids (eg, corticosterone, progesterone and testosterone) were in equilibrium between the brain and periphery, whereas other steroids (eg, pregnenolone (PREG), 5α/β-dihydroprogesterone and oestrogens) were more concentrated in the brain. In the brain regions investigated, PREG sulphate, progesterone and oestrogen concentrations were higher in the hypothalamus-preoptic area.Progesterone and its metabolites were more concentrated in the female than the male brain, whereas testosterone, its metabolites and dehydroepiandrosterone were more concentrated in males, suggesting that sex steroids present in quail brain mainly depend on their specific steroidogenic pathways in the ovaries and testes. However, the results of castration experiments suggested that sex steroids could also be produced in the brain independently of the peripheral source. Treatment with testosterone or oestradiol restored the concentrations of most androgens or oestrogens, respectively, although penetration of oestradiol in the brain appeared to be more limited. These studies illustrate the complex interaction between local brain synthesis and the supply from the periphery for the steroids present in the brain that are either directly active or represent the substrate of centrally located enzymes. K E Y W O R D Sbrain aromatisation, brain steroid concentrations, gas chromatography, mass spectrometry, preoptic area (16:8 hour light/dark photocycle). We first describe the methods that are common to all experiments and, in a second step, we describe the specific protocols of each experiment.All experimental procedures were conducted in agreement with the Belgian and French laws on the "Protection and Welfare of Animals" and on the "Protection of experimental animals" and were approved by the Ethics Committee for the Use of Animals at the University of Liège. | Brain collection and dissectionBirds were rapidly killed by decapitation without anaesthesia to avoid potential changes in steroid concentrations. Trunk blood was collected and, after centrifugation, serum was stored at −80°C until assayed for steroid content (0.5-1.0 mL used in the assays). Brains were immediately extracted from the skull and dissected into four great subdivisions: the hypothalamus-POA (30-60 mg), the telencephalon (TEL) (300-450 mg), the optic lobes (OL) (120-180 mg) and the cerebellum (CB) (90-110 mg)....

show abstract

“…Moreover, to the best of our knowledge, no study has compared changes in central steroid levels in response to stress in male and female rats in the same experiment. Traditional detection methods such as radioimmunoassays incur limitations: cross‐reactivity issues may hinder accuracy, whereas low throughput and low sensitivity makes quantification of a panel of structurally related steroids in discrete brain regions difficult …”

Section: Introductionmentioning

confidence: 99%

Sex‐dependent changes in neuroactive steroid concentrations in the rat brain following acute swim stress

Sze

Gill

Brunton

2018

J Neuroendocrinology

View full text Add to dashboard Cite

Sex differences in hypothalamic‐pituitary‐adrenal (HPA) axis activity are well established in rodents. In addition to glucocorticoids, stress also stimulates the secretion of progesterone and deoxycorticosterone (DOC) from the adrenal gland. Neuroactive steroid metabolites of these precursors can modulate HPA axis function; however, it is not known whether levels of these steroids differ between male and females following stress. In the present study, we aimed to establish whether neuroactive steroid concentrations in the brain display sex‐ and/or region‐specific differences under basal conditions and following exposure to acute stress. Brains were collected from male and female rats killed under nonstress conditions or following exposure to forced swimming. Liquid chromatography‐mass spectrometry was used to quantify eight steroids: corticosterone, DOC, dihydrodeoxycorticosterone (DHDOC), pregnenolone, progesterone, dihydroprogesterone (DHP), allopregnanolone and testosterone in plasma, and in five brain regions (frontal cortex, hypothalamus, hippocampus, amygdala and brainstem). Corticosterone, DOC and progesterone concentrations were significantly greater in the plasma and brain of both sexes following stress; however, the responses in plasma were greater in females compared to males. This sex difference was also observed in the majority of brain regions for DOC and progesterone but not for corticosterone. Despite observing no stress‐induced changes in circulating concentrations of pregnenolone, DHDOC or DHP, concentrations were significantly greater in the brain and this effect was more pronounced in females than males. Basal plasma and brain concentrations of allopregnanolone were significantly higher in females; moreover, stress had a greater impact on central allopregnanolone concentrations in females. Stress had no effect on circulating or brain concentrations of testosterone in males. These data indicate the existence of sex and regional differences in the generation of neuroactive steroids in the brain following acute stress, especially for the 5α‐reduced steroids, and further suggest a sex‐specific expression of steroidogenic enzymes in the brain. Thus, differential neurosteroidogenesis may contribute to sex differences in HPA axis responses to stress.

show abstract

Analytical challenges for measuring steroid responses to stress, neurodegeneration and injury in the central nervous system

Cited by 38 publications

References 242 publications

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Queen mandibular pheromone modulates hemolymph ecdysteroid titers in adult Apis mellifera workers

Steroid profiles in quail brain and serum: Sex and regional differences and effects of castration with steroid replacement

Sex‐dependent changes in neuroactive steroid concentrations in the rat brain following acute swim stress

Contact Info

Product

Resources

About