title: A histological study on the effect of pressure therapy on the activities of myofibroblasts and keratinocytes in hypertrophic scar tissues after burn.
abstract: Although pressure therapy (PT) has been widely used as the first-line treatment for hypertrophic scars (HS), the histopathological changes involved have seldom been studied. This study aimed to examine the longitudinal effect of PT on the histopathological changes in HS. Ten scar samples were selected from six patients with HS after burn and they were given a standardized PT intervention for 3 months while 16 scar samples were obtained on those without PT. The scar biopsies were collected pre-treatment, 1 and 3 months post-intervention for both clinical and histopathological examinations. Clinical assessments demonstrated significant improvement in the thickness and redness of the scars after PT. Histological examination revealed that cell density in the dermal layer was markedly reduced in the 3-months post-pressurized scar tissues, while the arrangement of the collagen fiber was changed from nodular to wave-like pattern. The α-smooth muscle actin immunoreactivity was significantly decreased after 1-month pressure treatment. There was a significant reduction of myofibroblasts population and a concomitant increase in the apoptotic index in the dermal layer in the 3-months' post-pressurized scars. A significant negative correlation was found between the myofibroblasts population and the apoptotic index. The keratinocyte proliferation was found inhibited after PT. Results demonstrated that PT appeared to promote HS maturation by inhibiting the keratinocyte proliferation and suppressing myofibroblasts population, the latter possibly via apoptosis.
authors: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. Electronic address: cecilia.li@polyu.edu.hk.
authors: Cecilia W P
authors: CW
authors: Li-Tsang
authors: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors: Beibei
authors: B
authors: Feng
authors: Division of Plastic, Reconstructive and Aesthetic Surgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong.
authors: Lin
authors: L
authors: Huang
authors: Burns Unit, 1st Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors: Xusheng
authors: X
authors: Liu
authors: Burns Unit, 1st Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors: Bin
authors: B
authors: Shu
authors: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors: Yvonne T Y
authors: YT
authors: Chan
authors: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
authors: Kwok-Kuen
authors: KK
authors: Cheung
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D017209:Apoptosis; D002056:Burns / Q000150:complications*; D002452:Cell Count; D002648:Child; D017439:Cicatrix, Hypertrophic / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D015331:Cohort Studies; D058128:Compression Bandages; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D015603:Keratinocytes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology*; D011312:Pressure; D012867:Skin / Q000473:pathology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C541116:ACTA2 protein, human; D000199:Actins
keywords: Apoptosis; Hypertrophic scar; Keratinocytes; Myofibroblasts; Pressure intervention