Molecular Pathogenesis of Chronic Wounds

Stojadinović, Olivera; Brem, Harold; Vouthounis, Constantinos; Lee, Brian; Fallon, John F.; Stallcup, Michael R.; Merchant, Ankit; Galiano, Robert D.; Tomic‐Canic, Marjana

doi:10.1016/s0002-9440(10)62953-7

Cited by 308 publications

(156 citation statements)

References 57 publications

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“…Cell Culture-Normal human epidermal keratinocytes were grown as previously described (49). Cells were expanded through two passages before they were grown to 85% or 95% confluence.…”

Section: Methodsmentioning

confidence: 99%

Cortisol Synthesis in Epidermis Is Induced by IL-1 and Tissue Injury

Vukelic

Stojadinović

Pastar

et al. 2011

Journal of Biological Chemistry

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171

195

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Glucocorticoids (GCs) are known inhibitors of wound healing. In this study we report the novel finding that both keratinocytes in vitro and epidermis in vivo synthesize cortisol and how this synthesis regulates wound healing. We show that epidermis expresses enzymes essential for cortisol synthesis, including steroid 11 ␤-hydroxylase (CYP11B1), and an enzyme that controls negative feedback mechanism, 11␤-hydroxysteroid dehydrogenase 2 (11␤HSD2). We also found that cortisol synthesis in keratinocytes and skin can be stimulated by ACTH and inhibited by metyrapone (CYP11B1 enzyme inhibitor). Interestingly, IL-1␤, the first epidermal signal of tissue injury, induces the expression of CYP11B1 and increases cortisol production by keratinocytes. Additionally, we found induction of CYP11B1 increased production of cortisol and activation of GR pathway during wound healing ex vivo and in vivo using human and porcine wound models, respectively. Conversely, inhibition of cortisol synthesis during wound healing increases IL-1␤ production, suggesting that cortisol synthesis in epidermis may serve as a local negative feedback to proinflammatory cytokines. Local GCs synthesis, therefore, may provide control of the initial proinflammatory response, preventing excessive inflammation upon tissue injury. Inhibition of GC synthesis accelerated wound closure in vivo, providing the evidence that modulation of cortisol synthesis in epidermis may be an important regulatory mechanism during wound healing.Acute wound healing is a complex biological process mediated by a network of signaling pathways that coordinate multiple cellular processes, including cellular migration and proliferation, ultimately leading to barrier restoration (1). Wound healing is a tightly spatiotemporally regulated process, and changes in any component of this process can be detrimental, leading to further tissue damage or impairment of healing (2, 3).For example, timing of inflammatory response is essential; proinflammatory signals are important in the early stage of healing, but they can be detrimental if they persist (4, 5), underscoring a need for tight control of both stimulators and inhibitors during the wound healing process.Upon injury, keratinocytes are the first cells that respond (6, 7) by releasing pre-stored interleukin-1 (IL-1) (8). IL-1 has an autocrine and a paracrine function; that is, to activate keratinocytes and to alert the surrounding cells and tissues. The release of IL-1 by keratinocytes, with subsequent release of additional signaling molecules (9, 10), demarcates the proinflammatory phase of wound healing. In response to these signals, activated keratinocytes start migrating and proliferating (7,8,11). Successful repair after tissue injury requires resolution of inflammatory response, transitioning keratinocyte (HEK) from activated to differentiating phenotype. However, very little is known about endogenous epidermal signals that control keratinocyte activation cycle and inflammatory response.Epidermal keratinocytes have important immunol...

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“…Cell Culture-Normal human epidermal keratinocytes were grown as previously described (49). Cells were expanded through two passages before they were grown to 85% or 95% confluence.…”

Section: Methodsmentioning

confidence: 99%

Cortisol Synthesis in Epidermis Is Induced by IL-1 and Tissue Injury

Vukelic

Stojadinović

Pastar

et al. 2011

Journal of Biological Chemistry

Self Cite

171

195

View full text Add to dashboard Cite

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“…Wounds were created using 3-mm punch biopsies through the reticular dermis, and the specimens were maintained on an air-liquid interface for 4 and 7 days as previously reported (27). Each time point was collected in parallel with an unwounded skin specimen from the same donor.…”

Section: Methodsmentioning

confidence: 99%

Role of Scarf and Its Binding Target Proteins in Epidermal Calcium Homeostasis

Hwang

Kalinin

Hwang

et al. 2007

Journal of Biological Chemistry

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The novel Ca 2؉ -binding protein, Scarf (skin calmodulin-related factor) belongs to the calmodulin-like protein family and is expressed in the differentiated layers of the epidermis. To determine the roles of Scarf during stratification, we set out to identify the binding target proteins by affinity chromatography and subsequent analysis by mass spectrometry. Several binding factors, including 14-3-3s, annexins, calreticulin, ERp72 (endoplasmic reticulum protein 72), and nucleolin, were identified, and their interactions with Scarf were corroborated by co-immunoprecipitation and co-localization analyses. To further understand the functions of Scarf in epidermis in vivo, we altered the epidermal Ca 2؉ gradient by acute barrier disruption. The change in the expression levels of Scarf and its binding target proteins were determined by immunohistochemistry and Western blot analysis. The expression of Scarf, annexins, calreticulin, and ERp72 were up-regulated by Ca 2؉ gradient disruption, whereas the expression of 14-3-3s and nucleolin was reduced. Because annexins, calreticulin, and ERp72 have been implicated in Ca 2؉ -induced cellular trafficking, including the secretion of lamellar bodies and Ca 2؉ homeostasis, we propose that the interaction of Scarf with these proteins might be crucial in the process of barrier restoration. On the other hand, down-regulation of 14-3-3s and nucleolin is potentially involved in the process of keratinocyte differentiation and growth inhibition. The calcium-dependent localization and up-regulation of Scarf and its binding target proteins were studied in mouse keratinocytes treated with ionomycin and during the wound-healing process. We found increased expression and nuclear presence of Scarf in the epidermis of the wound edge 4 and 7 days post-wounding, entailing the role of Scarf in barrier restoration. Our results suggest that Scarf plays a critical role as a Ca 2؉ sensor, potentially regulating the function of its binding target proteins in a Ca 2؉ -dependent manner in the process of restoration of epidermal Ca 2؉ gradient as well as during epidermal barrier formation.

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“…The re-epithelialization process begins within several hours after injury and, given its role in the restoration of an intact epidermal barrier, is absolutely essential for optimal wound closure. The directed migration of keratinocytes is in turn essential for re-epithelialization, and defects in this function are associated with chronic nonhealing wounds, such as diabetic ulcers (Stojadinovic et al, 2005). Diabetic patients frequently suffer from severely impaired wound healing, with a lifetime risk of 15% for developing diabetic skin ulcerations.…”

Section: Tnf and Mmp9 Participate In 12-hht/blt2-dependent Keratinocymentioning

confidence: 99%