Selectively enhanced procollagen gene expression in sclerosing (morphea-like) basal cell carcinoma as reflected by elevated pro alpha 1(I) and pro alpha 1(III) procollagen messenger RNA steady-state levels

Sclerosing or morphea-like variant of basal cell carcinoma (BCC) is characterized by an extensive connective tissue stroma, and histopathology has suggested that the extracellular matrix is largely composed of collagen. In addition, fibronectin deposition has been proposed to modulate tumor growth in BCC. In this study, we examined the expression of genes coding for type I, III, and IV procollagens, as well as for fibronectin, in tissue from 10 patients with sclerosing BCC. For comparison, tissues from 5 patients with nodular BCC and 4 controls were examined. Total RNA was isolated by CsCl density gradient centrifugation, and messenger RNA (mRNA) steady-state levels were determined by slot-blot hybridizations with human sequence specific complementary DNAs (cDNAs). The abundance of type I procollagen mRNA in sclerosing BCC tissue was increased to 233.6 +/- 36.7% of the controls (mean +/- SEM). The corresponding value for type III procollagen mRNA in sclerosing BCC was 281.8 +/- 54.8% of the controls. Consequently, the steady-state ratio of type I/III procollagen mRNAs in sclerosing BCCs (5.0 +/- 1.2; mean +/- SD) was within the control range. Thus, there is a coordinate increase in type I and type III procollagen mRNA levels in sclerosing BCC. In contrast, the values for type I and type III procollagen mRNAs in nodular BCC were not different from the controls. In addition, type IV procollagen and fibronectin mRNA levels were not different from the controls either in sclerosing or nodular BCCs, attesting to the selectivity of the increase in type I and III procollagen mRNA levels in sclerosing BCC. These observations may relate to the excessive deposition of the extracellular matrix stroma surrounding the tumor cells in sclerosing BCC.     

Fibrillin microfibrils are reduced in skin exhibiting striae distensae

Striae distensae (striae: stretch marks) are a common disfiguring condition associated with continuous and progressive stretching of the skin—as occurs during pregnancy. The pathogenesis of striae is unknown but probably relates to changes in those structures that provide skin with its tensile strength and elasticity. Such structures are components of the extracellular matrix, including fibrillin, elastin and collagens. Using a variety of histological techniques, we assessed the distribution of these extracellular matrix components in skin affected by striae. Pregnant women were assessed for the presence of striae, and punch biopsies were obtained from lesional striae and adjacent normal skin. Biopsies were processed for electron microscopy, light microscopy and immunohistochemistry. For histological examination, 7 μm frozen sections were stained so as to identify the elastic fibre network and glycosaminoglycans. Biopsies were also examined with a panel of polyclonal antibodies against collagens I and III, and fibrillin and elastin. Ultrastructural analysis revealed alterations in the appearance of skin affected by striae compared with that of normal skin in that the dermal matrix of striae was looser and more floccular. Light microscopy revealed an increase in glycosaminoglycan content in striae. Furthermore, the number of vertical fibrillin fibres subjacent to the dermal–epidermal junction (DEJ) and elastin fibres in the papillary dermis was significantly reduced in striae compared with normal skin. The orientation of elastin and fibrillin fibres in the deep dermis showed realignment in that the fibres ran parallel to the DEJ. However, no significant alterations were observed in any other extracellular matrix components. This study identifies a reorganization and diminution of the elastic fibre network of skin affected by striae. Continuous strain on the dermal extracellular matrix, as occurs during pregnancy, may remodel the elastic fibre network in susceptible individuals and manifest clinically as striae distensae.     

Anatomy of striae

The histopathology of striae distensae is disputed; different authorities give contradictory accounts of the microscopic changes, especially in elastic fibres. We re-evaluated the problem by taking eight elliptical biopsies across striae. Six were examined by light microscopy with appropriate stains for elastin and collagen. Two were prepared for scanning electronmicroscopy (s.e.m.), using a procedure which removes collagen, enabling the elastic network to be seen in its native form. By light microscopy, striae were sharply demarcated from normal skin, consisting mainly of fine, straight bundles of collagen arranged parallel to the surface. Fine elastic fibres were disposed similarly without fragmentation, fraying or curling. By s.e.m., the elastic network was found to be extraordinarily dense and well developed with many fine, curled fibres in random array. It was evident that the routine stains for elastin greatly underestimated the abundance of elastic fibres, probably because immature fibres contain insufficient protein matrix. The horizontal packing of collagen bundles was confirmed by s.e.m. These findings support the view that striae distensae are scars. There is no evidence that they form by stress-induced rupture of the connective tissue.     

Quantitative analysis of α1(I) and α1(III) procollagen mRNA expression in systemic sclerosis skin tissue – an in situ hybridization study

Abstract Human α1(I) and α1(III) procollagen mRNA expression in skin tissue from 15 systemic sclerosis (SSc) patients and from 7 normal control subjects was quantitatively analyzed using in situ hybridization. The grains accumulating in each area, representing procollagen mRNA expression per cell, were counted. To normalize the results from each subject, the number of cells and the number of grains per cell were divided by the area of the skin specimen (in square millimeters). The number of cells per square millimeter expressing α<1(I) and α1(III) procollagen mRNA in SSc skin was significantly elevated compared with normal control skin (both P < 0.01). The number of grains per cell per square millimeter expressing α1(III) procollagen mRNA in SSc skin was also significantly elevated compared with normal control skin (P < 0.01). The relationship between procollagen mRNA expression and the histological findings in SSc was also studied. The numbers of cells and grains per cell per square millimeter expressing α1(I) procollagen mRNA in fibrotic zone SSc skin were significantly elevated compared with normal control skin (both P < 0.01). The numbers of cells and grains per cell per square millimeter expressing α1(III) procollagen mRNA in SSc skin were significantly elevated compared with normal control skin (both P < 0.01) and with border zone SSc skin (number of cells P < 0.01, number of grains P < 0.05). These results indicate an increase in the number of cells showing elevated expression of α1(I) and α1(III) procollagen mRNA, and a close relationship between α1(I) and α1(III) procollagen mRNA expression and the histological findings in SSc. Received: 24 February 1999 / Received after revision: 20 May 1999 / Accepted: 16 August 1999     

Contractile forces generated by striae distensae fibroblasts embedded in collagen lattices

Striae distensae are characterized by linear, smooth bands of atrophic-appearing skin that are reddish at first and finally white. They are due to stretching of the skin, as in rapid weight gain, or mechanical stress, as in weight lifting. The pathogenesis of striae distensae is unknown but probably relates to changes in the fibroblast phenotype. In order to characterize striae distensae fibroblasts, alpha-smooth muscle actin expression and contractile forces were studied. Five healthy women with early erythematous striae and five healthy women with older striae were selected. Paired biopsies were taken from the center of lesional striae and adjacent normal skin. Fibroblasts were obtained by an explant technique and expanded in vitro in Dulbecco’s modified Eagle‘s medium. Contractile forces generated by fibroblasts in collagen lattices were measured with the Glasbox device developed in our laboratory. Alpha-smooth muscle actin expression was studied by immunofluorescence labeling of cells and by flow cytometry. Fibroblasts from early striae distensae were the richest cells in alpha-smooth muscle actin filaments and generated the highest contractile forces. Their peak contractile force was 26% greater than normal fibroblasts. There was a 150% higher level of alpha-smooth muscle actin content in fibroblasts from early striae distensae compared with fibroblasts from normal skin. In contrast, there was no significant difference in force generation between old striae fibroblasts and normal fibroblasts with cells expressing no alpha-smooth muscle actin. The contractile properties of fibroblasts from striae distensae varies depending on the stage of the disease. In early striae distensae, fibroblasts acquire a more contractile phenotype, corresponding to that of myofibroblasts.     

Scleredema adultorum: case report and demonstration of abnormal expression of extracellular matrix genes in skin fibroblasts in vivo and in vitro

Summary To elucidate the mechanisms involved in the development of cutaneous fibrosis in scleredema adultorum. we studied a patient with long-standing scleredema who had no history of diabetes mellitus or preceding febrile illness. Histological examination of a biopsy specimen from involved forearm skin demonstrated marked thickening of the dermis and accumulation of mucin between collagen bundles. Increased levels of type I collagen mRNA. as evidenced by positive in situ hybridization signals with an α1(I) procollagen cDNA were found in numerous fibroblasts throughout the dermis. The expression of several genes coding for proteins involved in the maintenance of connective tissue was examined by determining in vitro protein production and mRNA levels in fibroblasts from the affected skin. Total protein production, glucosamine incorporation and collagen synthesis, were elevated by 44–97% in scleredema fibroblasts, compared with fibroblasts from two healthy individuals. Levels of mRNAs for α1(I) and α1(III) procollagens and fibronectin were elevated in scleredema fibroblasts, whereas mRNA levels for the tissue inhibitor of metalloproteinase were unaltered compared with control cultures. The results suggest that fibroblasts from the involved skin in non-diabetic patients with scleredema may exhibit a biosynthetically activated phenotype, which persists for several years. These alterations are likely to be involved in the development of the cutaneous induration and thickening which is characteristic of this disease.     

Immunochemistry of elastotic material in sun-damaged skin

The nature of elastotic material in sun-damaged human skin was investigated by indirect immunofluorescence. Antibodies were used against the following components of the dermis: type I and type VI collagens, aminopropeptide of type I and type III procollagens, fibronectin, elastin, microfibrillar proteins, and basement membrane represented by the 7S domain of type IV collagen, laminin, and nidogen. The elastotic material exhibited marked fluorescence for elastin and microfibrillar proteins which codistributed with fibronectin. The presence of type I and VI collagens and procollagen type III were demonstrated to a lesser extent within the elastotic material. These results suggest that solar elastosis is primarily derived from elastic fibers and not from preexisting or newly synthesized collagens.     

High-resolution epiluminescence colorimetry of striae distensae

BACKGROUND: Colours of striae distensae are often different from that of the surrounding skin. A close look using dermoscopy discloses distinct patterns of melanized networks at these sites. The aim of the study was to design a method of high-\resolution analytical analysis of the skin colours using the combination of photographic dermoscopy and small field reflectance colorimetry. METHODS: Clinical photographs were taken from striae distensae and their surrounding skin using a Dermaphot (Heine Optotechnik, Hersching, Germany). A final magnification of 125x was obtained on paper photographs. The reflectance colorimeter Visi-Chroma VC-100 (Biophotonics, Lessines, Belgium) was used to measure colours of the pigmentary networks in the L*a*b* system. Differential colour parameters (deltaE*ab, deltaL*, deltaa*, deltab*) were calculated for each case between the lesional and the surrounding normal skin, and between the melanized reticulated pattern and the enclosed lighter areas. RESULTS: Objective colorimetric assessments distinguished four distinct types, namely striae albae, striae rubrae, striae caeruleae and striae nigrae. The latter peculiar hyperpigmented type of striae distensae was specifically identified by epiluminescence examination in dark-skinned subjects. The fine-melanized honeycomb network present on the adjacent intact skin was reshaped inside striae in a streaky pattern perpendicular to the striae axis. Strong linear correlations were found between all combinations of deltaL* and deltab* evaluating colours of the reticulated and the honeycomb alveolar patterns both inside and outside the striae distensae. By contrast, no correlations were found between deltaa* and the other colorimetric parameters. CONCLUSION: The direct and/or indirect influences of melanocyte mechanobiology appear to have a prominent effect on the various colours of striae distensae.     

Expression of extracellular matrix proteins in reticular variant of mid‐dermal elastolysis

Background Mid‐dermal elastolysis (MDE) is a rare disorder of the elastic tissue that is characterized histopathologically by selective loss of elastic fibres in the mid dermis. Objective We aimed to investigate the protein and mRNA expression of extracellular matrix‐related proteins and growth factors in the skin (lesional and non‐lesional) of a female patient with the reticular variant of MDE. Methods Real‐time RT‐PCR and immunohistochemistry was performed for matrix metalloproteinase‐1 (MMP‐1), tissue inhibitor of metalloproteinase‐1, decorin, biglycan, versican, fibronectin, elastin, extracellular matrix protein 1, cathepsin G, transforming growth factor ß1 and connective tissue growth factor. Results Although protein expression of decorin, biglycan and versican was reduced in the mid dermis of lesional skin, mRNA expression did not differ between lesional and non‐lesional skin. As expected, elastin expression was significantly diminished in the mid dermis of lesional skin, whereas mRNA expression levels of elastin were equal to non‐lesional skin. Immunoreactivity of MMP‐1 was increased in lesional upper and mid dermis. Accordingly, MMP‐1 mRNA was also significantly higher expressed in MDE when compared with non‐lesional skin. Conclusions The results of this study confirm data of the previous investigations indicating that increased MMP‐1 activity followed by elastin degradation seems to constitute the pathogenetic background of MDE.     

Striae distensae of pregnancy. An in vivo biomechanical evaluation

Background and objective Striae distensae of pregnancy is a common finding. There is currently a lack of information about the rheological characteristics of such lesions. The purpose of this study was to compare the mechanical properties of striae distensae before and after delivery. Patients and methods A total of 79 primigravid entered the study. Rheological properties of skin were evaluated in vivo using a Cutometer® equipped with a 2-mm probe. Results Mechanical properties of striae distensae developing during pregnancy resembled those of the surrounding skin. By contrast, significant differences were yielded during post-partum. Extensibility of striae distensae was increased although parameters of elasticity remained normal. Conclusions Rheological properties of striae distensae of pregnancy vary in time. This might reflect the changes in hormones and in the mechanical stresses normally setting the skin under tension.     

Collagen mRNA expression detected by in situ hybridization in keloid tissue

The keloid fibroblasts exhibited increased extracellular matrix gene expression, and prominent elevated type I procollagen mRNA when compared to control fibroblasts cultured from the uninvolved skin of normal people. It also showed markedly elevated type I/III procollagen mRNA ratios, but no synthesis of type IV procollagen mRNA by keloid fibroblasts was observed. By in situ hybridization in keloid tissue, high levels of type I and type III procollagen mRNAs were detected in most of the fibroblasts, suggesting the presence of a subpopulation responsible for the increased collagen production. The levels of type I and type III procollagen mRNAs in these fibroblasts were clearly elevated compared to control skin specimens. And concentration of type I procollagen mRNA was found more predominantly than was type III. These results suggest that deposition of collagen in keloid could result from activation of certain fibroblasts responsible for type I procollagen production.     

Clinical features and risk factors for striae distensae in Korean adolescents

BACKGROUND: Despite the high prevalence of striae distensae, clinical studies are few in number, and their pathophysiology still obscure. OBJECTIVES: To determine the prevalence and clinical characteristics of striae distensae that occur in Korean adolescents, and to correlate their clinical features with family history, other dermatological conditions, and body measurements. METHODS: One hundred and fifty-seven healthy Korean students, aged 15 to 17, were studied. A questionnaire and physical examination were employed to assess the subjects' past and family history, and the distribution, clinical features and severity of striae distensae. RESULTS: Striae distensae were present in 131 subjects (83.4%). Ninety-four (88.2%) of 109 male and 37 (77.1%) of 48 female subjects were affected. The striae were white in colour in 69.5% and asymptomatic in most of the subjects. They developed at an average age of 13.8 years. Family history was present in 18 subjects (11.5%). Seborrhoea of the face was positively correlated (P < 0.035) with striae distensae, and atopic dermatitis negatively correlated (P < 0.001). In both sexes, the buttock was the most prevalent area of striae development, followed by the lower back and knee in boys and by the thigh and calf in girls. Striae were significantly more common on the thigh of girls and on the knee of boys. CONCLUSIONS: Our results indicate that striae distensae are a common skin condition that occurs early in puberty regardless of gender, and that they have a different anatomical distribution and relationship with body measurements in each gender.     

Collagen gene expression in keloids: analysis of collagen metabolism and type I, III, IV, and V procollagen mRNAs in keloid tissue and keloid fibroblast cultures

Regulation of collagen gene expression was studied in keloids and fibroblast cultures established from keloid biopsies from 9 patients. The collagen concentration in keloid tissue was not different from that in normal skin. The activities of 2 enzymes catalyzing intracellular collagen biosynthesis, prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT) were significantly elevated in the keloids, the mean increase in the former enzyme being 5-fold and in the latter 3-fold with respect to the controls. The mean procollagen production rate in the keloid fibroblasts was at the control level, with only 1 keloid cell line showing a procollagen synthesis rate higher than the mean value + 2 SD of the controls. The mean PH and GGT activities of the keloid fibroblasts were not elevated, but PH activity in 2 cell lines and GGT activity in 1 cell line were higher than the mean + 2 SD for the controls. Cellular type I, III, IV, and V procollagen mRNAs were measured by slot blot hybridization using specific human cDNA clones for the various collagen types. The amounts of type I, III, and V procollagen mRNAs corresponded to the ratios in which these collagen types are produced by fibroblasts. No synthesis of type IV procollagen mRNA by keloid fibroblasts was observed. The total amount of type I and III procollagen mRNAs correlated significantly (p less than 0.01) with the procollagen synthesis rate measured after radioactive labeling of the cells in the keloid and control fibroblasts, indicating that collagen production in these cells is mainly controlled by regulating the final steady state levels of collagen mRNA. The results suggest that fibroblasts isolated from keloids often synthesize normal amounts of collagen.     

Lack of co-ordinate expression of the alpha1(I) and alpha1(III) procollagen genes in fibroblast clonal cultures

BACKGROUND: Several extracellular matrix genes, most notably alpha1(I) and alpha1(III) procollagen, are reported to be co-ordinately expressed in cultures of dermal fibroblasts. However, it remains unclear whether the expression of these genes is truly co-ordinate or whether it may be the result of averaging the phenotypic expression of different fibroblast subpopulations present within each culture. Objectives To determine by Northern analysis the correlation between alpha1(I) and alpha1(III) procollagen mRNA levels in clonal populations of human dermal fibroblasts. METHODS: As previously described, clonal cultures were derived from parent strains of human dermal fibroblasts by a microscopically controlled dilution technique and by stimulation of single cells with low oxygen tension in the early phases of clonal growth. RESULTS: In agreement with previous reports, we found that baseline steady-state levels of alpha1(I) procollagen mRNA were co-ordinately regulated with the alpha1(III) procollagen mRNA in 26 parent strains (r = 0. 9003; P < 0.0001). However, this close correlation between the expression of these two procollagen chains was absent in a total of 40 unselected clonal strains derived from four of the parent cultures (r = 0.5745; P < 0.0001). Moreover, this intrachain heterogeneity in alpha1(I) and alpha1(III) procollagen mRNA levels in clonal cultures was statistically significant from that measured in parent strains (P = 0.0016). CONCLUSIONS: alpha1(I) and alpha1(III) procollagen mRNA levels in clonal cultures do not show the tight co-ordinate regulation observed in non-clonal cultures, suggesting that these two genes operate under different sets of regulatory controls. This clonal heterogeneity may provide additional flexibility to the process of tissue repair and fibroblast clonal expansion.     

Bleomycin increases steady-state levels of type I collagen, fibronectin and decorin mRNAs in human skin fibroblasts

Abstract Bleomycin is a drug capable of inducing tissue fibrosis. In this study, the effects of bleomycin on gene expression of extracellular matrix encoding ·1(I) collagen, fibronectin and decorin were determined in vitro in human dermal fibroblasts. Northern blot analysis showed that bleomycin upregulated ·1(I) collagen, fibronectin and decorin gene expression dose-dependently between 1 nM and 1 μM. Bleomycin at 100 nM upregulated α1(I) collagen, fibronectin and decorin mRNA expression with a peak at 6 h following stimulation in normal skin fibroblast monolayers. Bleomycin enhanced mRNA expression encoding these extracellular matrix proteins in both normal dermal and scleroderma fibroblasts. Concomitant stimulation with bleomycin and interferon-γ (1000 U/ml), a representative antifibrotic cytokine, decreased ·1(I) collagen mRNA expression. Bleomycin also mildly upregulated mRNA expression of transforming growth factor-‚ (TGF-‚) and connective tissue growth factor (CTGF) coordinately in normal skin fibroblasts. Our results indicate that bleomycin modulates gene expression of extracellular matrix proteins in dermal fibroblasts, and this effect may be mediated by TGF-‚ and CTGF. Received: 20 April 2000 / Revised: 19 June 2000 / Accepted: 4 September 2000     

Efficacy of intradermal radiofrequency combined with autologous platelet‐rich plasma in striae distensae: a pilot study

Background Different types of laser have recently been reported as effective tools of treatment in striae distensae. Although fractional photothermolysis is effective for striae distensae, post‐inflammatory hyperpigmentation is a major concern and common complication. There are no reports of the effects of using an intradermal radiofrequency (RF) device in striae distensae. Autologous platelet‐rich plasma (PRP) is an effective treatment known for its wound‐healing effects. Methods Nineteen Asian female patients with striae distensae were enrolled in this study. Three sessions of intradermal RF (1134‐kHz frequency, 12‐W power, 26‐G electrode size) combined with autologous PRP were performed in each patient at intervals of four weeks. Patients were evaluated subjectively by the investigators and by themselves. Results Evaluation of clinical results at four weeks after treatment showed that only one (5.3%) of the 19 patients achieved excellent improvement, whereas seven (36.8%) demonstrated marked improvement, six (31.6%) showed moderate improvement, and five (26.3%) showed mild improvement. None of the patients showed worsening of striae distensae. A total of 63.2% of patients reported they were “satisfied” or “very satisfied” with the degree of overall improvement. Conclusions Intradermal RF combined with autologous PRP appears to be an effective treatment for striae distensae.     

Treatment of striae distensae using fractional ablative CO2 laser in skin types II-IV: a retrospective case series study

Striae distensae (SD) are atrophic dermal scars often found on abdomen, breasts, thighs, and hips of pregnant women. The strias’ self-healing without any intervention is a poor possibility. Till now, several lasers and light sources have been used for treatment of SD. However, there are no integrated therapeutic approaches determined for treatment of SD yet. So, in this study, the therapeutic effect of fractional ablative CO₂ laser in women with pregnancy was assessed. Twenty-four ethic Iranian women aged between 20 and 42 years with various severity of pregnancy SD enrolled in retrospective case series study. Participants with skin types II-IV were treated in four sessions with a one-month interval by fractional ablative CO₂ laser. The severity of striae was determined by Daveys scoring. Clinical improvement was assessed by comparing pretreatment and posttreatment clinical photographs based on global improvement scoring. The evaluation of clinical results showed that fractional ablative CO₂ laser was an effective treatment. Twenty of 24 (83.3%) patients showed improvement. Clinical improvement was affected by striae severity (P = 0.03). Also, there were no statistical differences between clinical improvements with skin types, striae scar severity, number of pregnancy, and striae location.