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?

http://www.kf6nvr.net/blog/archives/images/computing_stress.jpg

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