Human β‐defensin‐2 expression is increased in chronic wounds

Abstract

First identified in psoriatic epidermis and subsequently in other inflammatory cutaneous lesions, human beta-defensin-2 (hbetaD-2) is one of two endogenous antimicrobial peptides related to defensins in plants and animals. Our objective was to determine the expression of hbetaD-2 after injury and in chronic wounds. Biopsies of normal ipsilateral thigh skin and wound edges were taken from nine consecutive patients with venous leg ulcers (day 1) and from the same biopsy sites 2 days later (day 3). Sequential samples were also obtained from intact or meshed bilayered bioengineered skin consisting of neonatal human keratinocytes and dermal fibroblasts in a collagen matrix. Specimens were processed and immunostained for hbetaD-2 using a polyclonal rabbit antibody. In both human tissues and bioengineered skin, staining for hbetaD-2 was confined to the upper epidermal layers, sparing the basal cells. Analysis of 26 tissue samples from patients showed that normal skin had no hbetaD-2 expression but that marked up-regulation occurred after wounding by day 3. Conversely, chronic ulcers showed moderate-to-strong immunostaining for hbetaD-2 at baseline on day 1, with little or no change in intensity after wounding by day 3. In vitro, bioengineered skin showed increased distribution of cytoplasmic hbetaD-2 immunostaining after meshing. We conclude that the expression of hbetaD-2 is up-regulated after injury. Chronic wounds uniformly show a constitutively high baseline expression of hbetaD-2, possibly due to ongoing tissue injury and bacterial colonization.

Antimicrobial and antiviral effects of human defensins: pathogenetic value and prospective application to medicinal therapy

“…В более поздних исследова-ниях установлено, что β-дефенсины стимулируют миграцию и пролиферацию эпидермальных керати-ноцитов и, таким образом, способствуют заживле-нию ран [146]. Предполагается, что дефенсин hBD-2 активизируется при хронических и острых язвах, по-скольку в здоровой коже он не определяется [43]. Исследование содержания дефенсинов в образцах от пациентов при лечении травмы ортопедического и хирургического профиля показало эффективность использования обогащенной тромбоцитами плаз-мы.…”

Innate Immune Defense System of the Skin

“…73 Chronic wounds have a higher baseline expression of hBD2, probably maintained by ongoing tissue damage and bacterial exposure. 74 Middle-to long-chain sebum free fatty acids lauric acid, palmitic acid and oleic acid enhance the innate immune defense of the skin by inducing hBD2 in human sebocytes. 75 Antimicrobial functions Human BD1 exhibits minor antimicrobial activity compared with other defensins.…”

The Natural Antimicrobial Chromogranins/Secretogranins- Derived Peptides – Production, Lytic Activity and Processing by Bacterial Proteases

“…It is probably released with lipid-like content of these lamellar bodies (Oren et al, 2003). hBD-2 is also up-regulated locally by infections (Radek & Gallo, 2007) or wounds (Butmarc et al, 2004). It has preferential bactericidal properties against Gram-negative bacteria (Harder et al, 1997) and like LL-37, its effect is sensitive to the concentration of NaCl.…”