elastin and Cicatrix--Hypertrophic

To provide information about the clinical presentation of hypertrophic scars and keloids based on their varied structural components.. This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.. After completing this continuing education activity, you should be able to: ABSTRACT: Hypertrophic scars and keloids are firm, raised, erythematous plaques or nodules that manifest when the cicatrix fails to properly heal. They result from pathologic wound healing and often cause pain and decreased quality of life. The appearance of such cosmetically unappealing scars affects the confidence and self-esteem of many patients. These scars can also cause dysfunction by interfering with flexion and extension across joints. Both possess some unique and distinct histochemical and physiologic characteristics that set them apart morphologically and at the molecular level. While these entities have been the focus of research for many years, differentiating between them remains challenging for clinicians.This article reviews the clinical presentation of aberrant scars and illustrates how they can be differentiated. It outlines their pathophysiology and emphasizes the unique molecular mechanisms underlying each disorder. It also examines how altered expression levels and the distribution of several factors may contribute to their unique clinical characteristics and presentation. Further research is needed to elucidate optimal treatments and preventive measures for these types of aberrant scarring.

Topics: Biopsy, Needle; Cicatrix, Hypertrophic; Collagen; Combined Modality Therapy; Diagnosis, Differential; Disease Progression; Education, Medical, Continuing; Elastin; Female; Fibrillin-1; Humans; Immunohistochemistry; Keloid; Male; Prognosis; Risk Assessment; Severity of Illness Index; Wound Healing; Wounds and Injuries

We have recently shown that Latent transforming growth factor-beta-1 binding protein-2 (LTBP-2) has a single high-affinity binding site for fibroblast growth factor-2 (FGF-2) and that LTBP-2 blocks FGF-2 induced cell proliferation. Both proteins showed strong co-localisation within keloid skin from a single patient. In the current study, using confocal microscopy, we have investigated the distribution of the two proteins in normal and fibrotic skin samples including normal scar tissue, hypertrophic scars and keloids from multiple patients. Consistently, little staining for either protein was detected in normal adult skin and normal scar samples but extensive co-localisation of the two proteins was observed in multiple examples of hypertrophic scars and keloids. LTBP-2 and FGF-2 were co-localised to fine fibrous elements within the extracellular matrix identified as elastic fibres by immunostaining with anti-fibrillin-1 and anti-elastin antibodies. Furthermore, qPCR analysis of RNA samples from multiple patients confirmed dramatically increased expression of LTBP-2 and FGF-2, similar TGF-beta 1, in hypertrophic scar compared to normal skin and scar tissue. Overall the results suggest that elevated LTBP-2 may bind and sequester FGF-2 on elastic fibres in fibrotic tissues and modulate FGF-2's influence on the repair and healing processes.

Topics: Adolescent; Adult; Binding Sites; Case-Control Studies; Cicatrix, Hypertrophic; Elastic Tissue; Elastin; Extracellular Matrix; Female; Fibrillin-1; Fibrillins; Fibroblast Growth Factor 2; Gene Expression Regulation; Humans; Keloid; Latent TGF-beta Binding Proteins; Male; Microfilament Proteins; Protein Binding; Re-Epithelialization; Signal Transduction; Skin; Transforming Growth Factor beta1

A noninvasive method using microscopy and spectroscopy for analysing the morphology of collagen and elastin and their biochemical variations in skin tissue will enable better understanding of the pathophysiology of hypertrophic scars and facilitate improved clinical management and treatment of this disease.. To obtain simultaneously microscopic images and spectra of collagen and elastin fibres in ex vivo skin tissues (normal skin and hypertrophic scar) using a nonlinear spectral imaging method, and to compare the morphological structure and spectral characteristics of collagen and elastin fibres in hypertrophic scar tissues with those of normal skin, to determine whether this approach has potential for in vivo assessment of the pathophysiology of human hypertrophic scars and for monitoring treatment responses as well as for tracking the process of development of hypertrophic scars in clinic.. Ex vivo human skin specimens obtained from six patients aged from 10 to 50 years old who were undergoing skin plastic surgery were examined. Five patients had hypertrophic scar lesions and one patient had no scar lesion before we obtained his skin specimen. A total of 30 tissue section samples of 30 mum thickness were analysed by the use of a nonlinear spectral imaging system consisting of a femtosecond excitation light source, a high-throughput scanning inverted microscope, and a spectral imaging detection system. The high-contrast and high-resolution second harmonic generation (SHG) images of collagen and two-photon excited fluorescence (TPEF) images of elastin fibres in hypertrophic scar tissues and normal skin were acquired using the extracting channel tool of the system. The emission spectra were analysed using the image-guided spectral analysis method. The depth-dependent decay constant of the SHG signal and the image texture characteristics of hypertrophic scar tissue and normal skin were used to quantitatively assess the amount, distribution and orientation of their collagen and elastin components.. Our experiments and data analyses demonstrated apparent differences between hypertrophic scar tissue and normal skin in terms of their morphological structure and the spectral characteristics of collagen and elastin fibres. These differences can potentially be used to distinguish hypertrophic scar tissues from normal skin and to evaluate treatment responses.. All the measurements were performed in backscattering geometry and demonstrated that nonlinear spectral imaging has the ability to differentiate hypertrophic scar tissue from normal skin based on noninvasive SHG imaging, and TPEF imaging revealed the microstructure and spectral features of collagen and elastin fibres. With the advances in spectral imaging apparatus miniaturization, we have good reason to believe that this approach can become a valuable tool for the in vivo pathophysiology study of human skin hypertrophic scars and for assessing the treatment responses of this disfiguring disease in clinic. It can also be used to track the development of hypertrophic scars and to study wound healing processes in a noninvasive fashion without biopsy, fixation, sectioning and the use of exogenous dyes or stains.

Topics: Adolescent; Adult; Child; Cicatrix, Hypertrophic; Collagen; Elastin; Extracellular Matrix; Female; Humans; Male; Microscopy, Fluorescence, Multiphoton; Middle Aged; Photons; Young Adult