Stress-dependent Glucocorticoids and
Proinflammatory Cytokines Impair Wound Healing
Carla Cueva
Biol 520
March 11th, 2009
Outline
• Introduction• Hypothesis• Experimental findings• Summary• Conclusions• Take home message• Future experiments• References
What is Stress?
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Stress
• Stress is defined as the process through which environmental demands exceed an individual’s perceived ability to cope, thereby resulting in affective, behavioral, and physiological changes.
• Stress has long been suspected to play a role in the etiology of many diseases, and numerous studies have confirmed that stress-induced disruption of neuroendocrine immune equilibrium is consequential to health.
• Stress and accompanying negative emotions of anxiety and depression can provoke increases in proinflammatory cytokines that are associated with a variety of diseases.
Vileikyte, 2007
Stess
• Environmental demands or stressors are assumed to impact on health through 2 interacting routes: – (a) directly, by activating the hypothalamic-
pituitary adrenal and the sympathetic-adrenal medullary axes, thereby resulting in downstream hormonal and immunologic changes, and
– (b) indirectly, by inducing negative emotions, which in turn impact on physiologic processes and/or behavioral patterns that influence health.
Vileikyte, 2007
Mechanisms by which Stress Influences Health
• Physiology of stress response
• Psychologic response to stress
• Behavioral response to stress
Vileikyte, 2007
Physiology of Stress Response
The Wound Healing Process
Vileikyte, 2007
Connections between the nervous and immune systems
Marques-Deak , 2005
Effects of glucocorticoids on immune-cell populations
Sternberg, 2006
Hypothesis
Glucocorticoids effects proinflammatory cytokines is the essential pathways by which stress affects wound healing
Experimental Findings
Hostile Marital Interactions, ProinflammatoryCytokine Production, and Wound Healing
- Married couples were admitted to a hospital research clinic
- Couples were subjected to both supportive and conflicting interactions
- Couple’s blister wounds and cytokine production (IL-6, TNFα, and IL-β) were measured
Findings:- Low hostile group showed ~
same (65%-70%) increase in IL-6 levels over 24 hours
- High hostile group showed an increase from 45% to 113% on Ill-6 levels
- High hostile group had higher TNF-α values before and after conflict task
Kiecolt-Glaser et al., 2005
Restraint Stress Slows Cutaneous Wound Healing in Mice
Padgett et al., 1998
- Female SKH-1 mice were subjected to restraint stress (RST) on conical tube for 15 hours- Control mice were not restraint - RST SKH-1 animals were injected subcutaneously with 25mg/kg glucocorticoid receptor antagonist RU40555 prior to RST
Androstenediol reduces the anti-inflammatory effectsof restraint stress during wound healing
Head et al., 2006
- CD1 male mice were subjected to RST prior to placement of cutaneous wounds. - Both FWD and RST mice were injected with 40mg/mL AED prior to wounding. - The rate of wound closure was assessed daily by photoplanimetry.
Findings: -RST slowed wound closure-AED treatment ameliorated suppressive effects of stress
FWD = food/water deprivedRST = restraint stressVEH = vehicle (DMSO:EtOH)AED = androstenediol
Androstenediol reduces the anti-inflammatory effectsof restraint stress during wound healing
Head et al., 2006
-At 3, 6, 12 and 24 hours post wounding, IL-1β and PDGF RNAs were quantified by RT-PCR for inflammatory gene expression.
Findings:- Significant effect of RST treatment post injury- AED treatment ameliorated RST effect.
FWD = food/water deprivedRST = restraint stressVEH = vehicle (DMSO:EtOH)AED = androstenediol
Restraint stress impairs early wound healing in mice via α-adrenergic but not β-adrenergic receptors
Eijkelkamp et al., 2007
- Dermal wounds by punch biopsy were placed on RST SKH-1 female mice - Prior to RST, mice were injected with either phentolamine or nadolo- Pictures were taken daily to measure wound closure/contraction
Findings:-RST induced impairments in wound size/contraction were reduced in phentolamine treated animals
FWD = food/water deprivedRST = restraint stressPhentolamine = non-specific α-adrenergic receptorNadolol = non-specific β-adrenergic receptor
Restraint stress impairs early wound healing in mice via α-adrenergic but not β-adrenergic receptors
Eijkelkamp et al., 2007
-FWD and RST groups were injected intravenously with 5mg/ml Evans blue prior to wounding to measure edema formation
Findings:-Phentoalamine prevented the reduction in edema that was observed in saline treated RST mice
Experimental Models of Stress and Wound Healing
Sheridan et al., 2004
- RST and social disruption (SDR) were used as stressors.- SDR: male C57BL/6 mice were introduced to aggressive intruder. - Cutaneous punch biopsy wound was placed on control or stressed (RST or SDR) C57BL/6 animals and the kinetics of wound healing were studied over 10 days.
Hyperbaric oxygen therapy ameliorates stress-impaired dermal wound healing
- Female SKH-1 mice were subjected to RST and hyperbaric oxygen therapy (HBO) twice a day for two hours during early wound healing- 3.5mm cutaneous wound placed by punch biopsy behind shoulder and photographed- Wound inducible nitric oxide synthase (iNOS) was studied for gene expression by RT-PCR from RNA isolated from tissue
Gajendrareddy et al., 2005
SummaryPaper Findings Support Critique
Kiecolt-Glaser et al., 2005 Married couples healed blister wounds more slowly after a conflictive interaction versus supportive marital interaction
Yes Study group not diversed
Padgett et al., 1998 RST mice had reduced cellularity in the margins of the wounds and higher levels of serum corticosterone
Yes, No None
Head et al., 2006 ADE as a potential therapeutic for tissue repair
Yes, No Did not suggest other antagonists
Sheridan et al., 2004 SDR-induced GC resistance was permissive to normal wound healing
No Only mentioned GC resistance
Eijkelkamp et al., 2007 α–adrenergic receptor blockade attenuated early impairment on wound closure/contraction in RTS mice
No Did not suggest other antagonists
Gajendrareddy et al., 2005 HBO corrects stress-impaired dermal wound healing
No Poor introduction
Conclusions
• Glucocorticoid and proinflammatory cytokines are important pathways in stress-derived wound healing
• However, other pathways such as SNS-dervied catecholamines (ex alpha-adrenergic receptors) are also involved in wound healing delay
Future Experiments
• RST and SDR treatment and vice versa to measure desensitizing to GC
• SDR and alpha-adrenergic receptors
• Alpha-adrenergic antogonist that can cross brain-blood barrier, use different antagonist
Take Home Message
Marques-Deak , 2005
ReferencesChristian, L. M., Graham, J. E., Padgett, D. A., Glaser, R., Kiecolt-Glaser, J. K. (2006). Stress and wound healing.
Neuroimmunomodulation, 13, 337-346 Eijkelkamp, N., Engeland, C. G., Gajendrareddy, P. K., Marucha, P. T. (2007). Restraint stress impairs early wound healing in
mice via alpha-adrenergic but not beta-adrenergic receptors. Brain, Behavior, and Immunity, 21, 409-412 Gajendrareddy, P. K., Sen, C. K., Horan, M. P., Marucha, P. T. (2005). Hyperbaric oxygen therapy ameliorates stress-impaired
dermal wound healing. Brain, Behavior, and Immunity, 19, 217-222
Head, C. C., Farrow, M. J., Sheridan, J. F., Padgett, D. A. (2006). Androstenediol reduces the anti-inflammatory effects of restraint stress during wound healing. Brain, Behavior, and Immunity, 20, 590-596
Kiecolt-Glaser, J. K., Loving, T. J., Stowell, J. R., Malarkey, W. B., Lemeshow, S., Dickinson, S. L., Glaser, R. (2005). Hostile Marital Interactions, Proinflammatory Cytokine Production, and Wound Healing. Arch Gen Psychiatry, 62, 1377-1384
Padgett, D. A., Marucha, P. T., Sheridan, J. F. (1998). Restraint stress slows cutaneous wound healing in mice. Brain, Behavior, and Immunity, 12, 64-73
Rojas, I., Padgett, D. A., Sheridan, J. F., Marucha, P. T. (2002). Stress-induced susceptibility to bacterial infection during cutaneous wound healing. Brain, Behavior, and Immunity, 16, 74-84
Sheridan, J. F., Padgett, D. A., Avitsur, R., Marucha, P. T. (2004). Experimental models of stress and wound healing. World
Journal of Surgery, 28, 327-330
Sternberg, E. M. (2006). Neural regulation of innate immunity: a coordinated nonspecific host response to pathogens. Nature reviews. Immunology, 6, 318–328
Vileikyte, L. (2007). Stress and wound healing. Clinics in Dermatology, 25, 49-55