Stress en depressie: neurobiologische basis

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1 Stress en depressie: neurobiologische basis
Prof. dr. Stephan Claes UPC K.U. Leuven Campus Leuven België

2 Stress en depressie: neurobiologische basis
Stress, de biologische stressrespons en depressie Genen, stressgevoeligheid en depressie Van in de moederschoot … Trauma en stressgevoeligheid Stress voor volwassenen

3 Wat is stress? Hans Selye ( ): “Stress is the nonspecific response of the body to any demand, whether it is caused by, or results in, pleasant or unpleasant conditions.”

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5 INTEGRATED STRESS RESPONSES
Outputs of the paraventricular nucleus (PVN) mediating autonomic en endocrine response to stress. Inputs: Autonomic: NTS & catecholaminergic A1/C1 neurons of Ventro Lateral Medulla (not shown) Humoral: e.g. Angiotensine II, via receptors in subfornical organ Stress activates the PVN via: - nc. Centralis Amygdalae - bed nc of stria terminalis - Nc Dorsomedialis Hypothalami (not shown) Effector neurons of PVN: Parvicellular neurons  CRH: to portal vessels of median eminence  +: anterior pituitary neurons  ACTH Magnocellular neurons  AVP  posterior pituitary  General circulation Autonomic neurons  Direct: Intermediolateral Cell Column (IML)  : Sympathoneural & adrenomedullary  Indirect: Rostral ventrolateral medulla  IML The stress response has different pathways, each ranging in latency and time of effect (Figure 2): ANS – Sympathetic system sends messages to the various organs in the fight or flight response. A signal goes out to the adrenal medulla to secrete epinepherine and nor-epinepherine. They send the organs into hyperdrive in their fight or flight response. Hormonally, there are 3 important steps: HPA Axis is activated and regulates the secretion of cortisol. A negative feedback loop works to control the organ function and direct the physiological functions (e.g. suppress immune system) as needed during the stressor. Vasopressin – Vasopressin and oxytocin are secreted to balance blood pressure Thyroxine Axis – Results in the production of Thyroxine and Triiodothyronine, which work to increase basal metabolic rate, and thus fight fatigue. Benarroch et al. Clinical Autonomic Disorders 3th edition R. Allen et al. Human Stress: It's nature and control (Minneapolis MN, Burgess, 1983)

6 De HPA as - Glucocorticoid receptor

7 Depressie en stress Acute stress, zoals verliessituaties of belangrijke tegenslagen. Dergelijke gebeurtenissen leiden tot een sterke verhoging van de kans op het optreden van depressie (1) Daarnaast is chronische stress belangrijk bij het uitlokken van de aandoening (2). Chronische milde stress leidt bij muizen tot een aantal biologische veranderingen en gedragsfenomenen die min of meer vergelijkbaar zijn met symptomen van MDD bij de mens (3). Fysiek of seksueel misbruik vroeg in het leven (4). 20% van de vrouwen die zijn blootgesteld aan seksueel misbruik als kind lijden aan psychiatrische problemen als volwassene, met depressieve klachten als meest voorkomende probleem, in vergelijking met 6,3% van de vrouwen zonder misbruikervaringen. Kendler, K. S., Karkowski, L. M., & Prescott, C. A. (1999). Causal relationship between stressful life events and the onset of major depression. American Journal of Psychiatry, 156, Tennant, C. (2002). Life events, stress and depression: a review of recent findings. Australian and New Zealand journal of psychiatry, 36, Grippo, A. J., Beltz, T. G., & Johnson, A. K. (2003). Behavioral and cardiovascular changes in the chronic mild stress model of depression. Physiology & behavior, 78, Mullen, P. E. et al Impact of sexual and physical abuse on women’s mental health. Lancet 1: 841–845.

8 Stress, HPA en depressie
MDD patiënten vertonen verhoogde cortisol secretie in bloed en urine (1, 2) CRH in CSV is verhoogd (3, 4) Depressieve suïcideslachtoffers tonen een verhoogd CRH in locus coeruleus en raphe nuclei (5) Negatieve feedback werkt minder goed bij MDD patiënten (DST, Dex-CRH test) (6) This slide summarizes some of the key findings on the function of the HPA axis in major depression, and I’m sure you are familiar with most of these data. Cortisol, the end product of the HPA axis, is increased in blood and urine of major depressive patients. The central stimulating hormone in the hypothalamus, corticotropin releasing factor, is higher in the cerebrospinal fluid of depressed patients compared to controls. Postmortem research showed that CRF is increased during depression in critical brain regions such as the locus coeruleus and the raphe nuclei. Finally, numerous studies starting from the nineteen seventies have indicated that the negative feedback in the HPA axis system is deficient. This can be shown with the simple Dexamethasone Suppression Test, or with the more complex combined Dexamethasone / CRF test. 1. Sachar EJ et al. Arch Gen Psychiatry 1970; 23: ; 2. Gold PW et al. Biol Psychiatry 2002; 52: 381-5; 3. Gold PW et al. Mol Psychiatry 2002; 7: ; 4. Nemeroff CB et al. Arch Gen Psychiatry 1988; 45: ; 5. Austin MC et al. Mol Psychiatry 2003; 8: ; 6. Zobel AW et al . Am J Psychiatry 1999: 156:

9 De HPA as en depressie - Glucocorticoid receptor

10 Stress en depressie: neurobiologische basis
Stress, de biologische stressrespons en depressie Genen, stressgevoeligheid en depressie Van in de moederschoot … Trauma en stressgevoeligheid Stress voor volwassenen

11 De glucocorticoïd receptor (GR)
Negatieve feedback bij sterke cortisolsecretie: vooral via GR In vitro and in vivo studies tonen een verlaagde sensitiviteit van GR bij depressieve patiënten (1) GR mRNA expressie en activiteit nemen toe na behandeling met antidepressiva(2, 3) For several reasons, the glucocorticoid receptor gene is a prime candidate for the vulnerability to develop major depression. First, the HPA axis negative feedback is mainly regulated by this protein, especially under situations of high cortisol secretion. Second, a number of studies, many of them by the research group of Carmine Pariante, show a reduced function of this receptor in depressed patients. lead to an increase of both the expression and the activity of the GR. Finally, rodents that have been subjected to early neglect develop a depression-like phenotype that is associated with decreased GR expression in the hippocampus. Pariante CM. Stress 7: , 2004. Pariante CM & Miller AH Biol. Psychiatry 49: , 2001. Carvalho et al. Neuropsychopharamcology , Mar 26. [Epub ahead of print], 2008

12 GR transgene diermodellen
GR +/- muizen (1) verminderde negatieve feedback regulatie Verhoogd “depressief gedrag” “time dependent forebrain-specific GR knockout mice” (2) hyperactiviteit van de HPA as wordt gecorrigeerd door chronische behandeling met imipramine A number of partial and conditional knockout mice models for the GR gene have been produces, of which I’ll only discuss 2. Ridder et al. produced a mouse strain with a 50% reduction of GR expression. These mice showed normal basal activity of the HPA axis, and reacted normally to anxiety tests. However, they showed a disinhibited HPA axis with an impaired negative feedback, and developed more helplessness behavior in animal models for depression. Interestingly, Ridder et al also found that these animals had a downregulation of brain-derived neurotrophic factor, BDNF, something also seen in humans with depression. Boyle et al reported on mice lacking the GR only in the forebrain. This produced a phenotype with striking similarities to human MDD. These animals showed HAP axis hyperactivity, impaired negative feedback, increased depression-like behavior in animal models such as the forced swim test and the tail suspension test and decreased pleasure seeking. Importantly, a number of these abnormalities are normalized by chronic treatment with the tricyclic antidepressant imipramine. Ridder S et al. J Neurosci 25: , 2005. Boyle MP et al. Proc Natl Acad Sci U S A 102: 473-8, 2005.

13 Mutaties/variaties in humaan GR gen
Val571Ala Ile747Met Ile559Asn Asp641Val Leu753phe R23K N363S GR N-terminal Domain DNA binding Ligand binding domain Mutation Functional effect on GR Resulting disease R23K Mildly decreased sensitivity ? N363S Increased sensitivity Bcl1 Ile559Asn Strongly decreased sensitivity Glucocorticoid resistance syndrome Val571Ala Decreased sensitivity Asp641Val Ile747Met Leu753Met Let’s look at the structure of the glucocorticoid receptor gene in a little more detail. The gene consists of 3 domains: the immunogenic domain, the DNA domain and the ligand binding domain. A number of mutations have been described in the ligand binding domain. These mutations are very rare, mostly only found in a single family. They lead to a strong reduction of the sensitivity of the receptor for cortisol, which leads to a combination of serious somatic symptoms summarized as “glucocorticoid resistance syndrome”. For our purpose, we are more interested in three polymorphisms in the immunogenic domain of the gene. First is a double mutation in aminoacids 22 and 23, changing the normal Arginine at codon 23 to Lycine. This mutation leads to a relative decrease in the sensitivity of glucocorticoid receptors. The third polymorphism, a mutation leading to an amino acid change from -to-serine change in codon 363, leads to an increased sensitivity of the HPA negative feedback. The latter three polymorphisms do not lead to an obvious disease, but a number of studies is trying to dissect their effect.

14 De Trier Sociale Stress Taak (TSST)
Goed gerepliceede stresstaak Individu geeft een speech voor een onbekend en onsympathiek publiek, gevolgd door een moeilijke rekentaak Sessie wordt op video opgenomen Test activateert de HPA ass (Cort en ACTH) op reproduceerbare manier

15 R23K: reaction to TSST R23K Mean p-val (Mann- Whitney) Basal G 0.76 A 0.65 0.130 +15min 1.03 0.67 0.011 +30 min 1.01 0.099 +45 min 0.83 0.50 0.064 + 60 min 0.54 0.42 0.244 Peak 1.21 0.87 0.024 Deltapeak 0.45 0.22 0.029 AUC 42.06 28.03 0.033 We know that the ER22/23EK mutation is associated with reduced function of the glucocorticoid receptor and non suppression after the administration of Dexamethasone. However, the effect of this variant on the cortisol response to psychosocial stress in unknown. What I show you here are preliminary data of our own study using the Trier Social Stress Test in children between 8 and 12 years old. These data should be considered with care, because out of the 106 children tested here, only 7 carried the mutation. However, a qualitative appraisal of the data shows that carriers of the mutation show a decreased cortisol response in saliva after exposure to the Trier Social Stress Test. Using a nonparametric approach, the differences between both groups are significant for the cortisol values after 15 minutes, and for the area under the curve en the peak values. van West et al., Eur Child Adolesc Psychiatry Mar 18. [Epub ahead of print]

16 N363S: reaction to psychosocial stress
Wüst et al. (2004) N363S: higher saliva and plasma cortisol responses after TSST in males Kumsta et al. (2007) A3669G: higher saliva and plasma ACTH responses after TSST FIG. 1. Salivary cortisol responses (±SEM) to the first stress exposure (A) and average responses (±SEM) to all three stress exposures (B) in the four experimental groups 1) Wüst S et al. Common polymorphisms in the glucocorticoid receptor gene are associated with adrenocortical responses to psychosocial stress. J Clin Endocrinol Metab 89: , 2004. 2) Kumsta R et al. Sex specific associations between common glucocorticoid receptor gene variants and hypothalamus-pituitary-adrenal axis responses to psychosocial stress. Biol Psychiatry 62: 863-9, 2007.

17 Hoe genetisch is depressie?
Meta-analyse van tweelingstudies in depressie (1) additieve genetische factoren: 37% (CI 31% - 42%) (niet-gedeelde) omgevingsfactoren: 63% (CI 58-67%) Is depressie meer genetisch bij vrouwen? Zweedse studie bij 15,392 tweelingen(2) Heritabiliteit bij vrouwen 42%, bij mannen 29 % A large number of family and twin studies show that genes do play a role in the vulnerability for depression. If you have a first degree family member with major depression, your own risk to develop the disorder is increased by a factor of almost 3. A meta-analysis of twin studies published by Kendler’s group show that about 40 % of the liability to develop major depression is accounted for by additive genetic factors, so by a combination of genes. The rest of the liability should be ascribed to environmental factors. The same research group recently published a very large study in more than 15,000 Swedish twins. The heritability estimates were comparable to previous studies, but turned out to be higher in women compared to men. This would imply that some of the genes for major depression are sex-specific in their effect. Sullivan et al. Am J Psychiatry 157: , 2000. Kendler KS et al. Am J Psychiatry 163: , 2006.

18 GR mutatie R23K bij depressie
A few weeks after our paper came out, van Rossum et al. from the Erasmus University in Rotterdam published a paper following an identical approach. In a German populations, they found a frequency of the mutation of 4 percent in controls, compared to 6 percent in depressive patients and eight percent in patients with recurrent major depression. So this is an independent replication of what we found. As you know, this is unfortunately quite rare in psychiatric genetics! 1. van West D et al. Glucocorticoid Receptor Gene-Based SNP Analysis in Patients with Recurrent Major Depression. Neuropsychopharmacology 31: 620-7, 2006. 2. van Rossum EF et al. Polymorphisms of the glucocorticoid receptor gene and major depression. Biol Psychiatry 59: 681-8, 2006.

19 Stress en depressie: neurobiologische basis
Stress, de biologische stressrespons en depressie Genen, stressgevoeligheid en depressie Van in de moederschoot … Trauma en stressgevoeligheid Stress voor volwassenen

20 Prenatale factoren: Maternele stress
Maternele stress verhoogt cortisolsecretie bij moeder (1) Hoge materneel CRF / cortisol leidt tot hogere cortisolsecretie bij de neonatus na 24 uur (2) Angst / depressie tijdens de zwangerschap: Verband met cortisolsecretie bij babies op 6 maanden (3) Verband met cortisolsecretie op 10 jaar (4) Verband met cortisolsecretie op jaar (5) Korebrits C et al., J Clin Endocrinol Metab May;83(5): Lundy BL et AL., Infant Behav Dev 1999; 22: Huot RL et al. Ann N Y Acad Sci Dec;1032:234-6. O'Connor TG et al. Biol Psychiatry Aug 1;58(3):211-7. Van Den Bergh B et al., in voorbereiding

21 Leuven stress and pregnancy study
Doel 1) Angst / stress meten tijdens drie momenten in de zwangerschap (10 / 20 / 30 weken) 2) Cortisol secretie (dagcurve) op dezelfde momenten 3) De invloed daarvan nagaan op de werking van de HPA-as bij de baby's op leeftijd van 4 maanden.

22 Mean CORT at Trim 1, 2 and 3

23 STUDY 1: RESULTS Trait anxiety at 2nd Trim
group 1 ≤ 45; group 2 > 45 p= 0.076 Mean CORT

24 STUDY 1: RESULTS Cortisol before and after inoculation in 4 months old babies (ug/dl)

25 Cortisol awakening response in pregnant women (2nd trim) and cortisol reactivity of babies 15 min after vaccination CORT response baby -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 CORT awakening response Trim 2 -2 -1 1 2 3

26 Prenatale stress: mechanisme?
Prenatal stress ? Veranderingen in gedrag en HPA-as functie

27 Prenatale stress: mechanisme?
Prenatal stress Veranderingen in genexpressie via epigenetische mechanismen Veranderingen in gedrag en HPA-as functie

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29 De glucocorticoid receptor en prenatale stress
Dieronderzoek: de effecten van prenatale stress worden geldeeltelijk gemedieerd via de epigenetische regulatie van GR genexpressie (1) Humaan onderzoek: Methylatie status van het GR gen in pasgeborenen lijkt geassocieerd met stemming van de moeder tijdens de zwangerschap (2) 1. Zhang TY et al. Maternal programming of defensive responses through sustained effects on gene expression. Biol Psychol Jul;73(1):72-89. 2. Oberlander TF et al. Prenatal exposure to maternal depression, neonatal methylation of human glucocorticoid receptor gene (NR3C1) and infant cortisol stress responses. Epigenetics 3: , 2008.

30 Stress en depressie: neurobiologische basis
Stress, de biologische stressrespons en depressie Genen, stressgevoeligheid en depressie Van in de moederschoot … Trauma en stressgevoeligheid Stress voor volwassenen

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33 HPA en vroegtijdig trauma
Verhoogde HPA as reactiviteit op psychosociale stress bij volwassen vrouwen met een geschiedenis van fysiek of sexueel misbruik als kind (1) Verhoogde ACTH respons op exogeen toegediend CRH bij vrouwen met traumageschiedenis (2) Vrouwen met voorgeschiedenis van fysiek/seksueel misbruik hebben kleiner volume van de linker hippocampus (3) Toxiciteit / inhibitie neuroneogenese thv CA3 regio / gyrus dentatus? Heim C et al. JAMA Aug 2;284(5):592-7. Heim C et al. Am J Psychiatry Apr;158(4): Vythilingam M et al. Am J Psychiatry Dec;159(12):

34 HPA en vroegtijdig trauma
Een in de tijd afgelijnd vroegtijdig psychologisch trauma kan blijvende biologische veranderingen veroorzaken in stress-respons systemen

35 Stress en depressie: neurobiologische basis
Stress, de biologische stressrespons en depressie Genen, stressgevoeligheid en depressie Van in de moederschoot … Trauma en stressgevoeligheid Stress voor volwassenen

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37 Pavlov’s “experimental neurosis”

38 Epigenetische modificaties door prenatale stress, trauma, … (GR, …)
Genetische aanleg (5-HTT, GR, BDNF, …) Kwetsbaar individu (Lagere tonus 5HT, instabiele HPA, …) Acute en/of chronische stress (Verdere activatie HPA-as, serotonerg systeem niet in staat om te compenseren, BDNF daalt verder) Optreden klinische symptomen van depressie