Genetic susceptibility to keloid disease and transforming growth factor beta 2 polymorphisms.

Keloid disease (KD) is a benign fibroproliferative scarring condition of unknown aetiopathogenesis. There is a familial predisposition to keloid scarring. The genes involved in the pathogenesis of abnormal dermal scarring have yet to be identified. Transforming growth factor beta (TGF beta) is a family of multifunctional cytokines, which play a central role in wound healing and fibrosis. The TGF beta 2 isoform is a member of this cytokine family and has previously been implicated in KD pathogenesis. We tested for an association between KD and two novel polymorphisms within the TGF beta 2 gene: an insertion polymorphism within the 59-untranslated region, 109 base pairs away from the initiation codon, and a single nucleotide polymorphism in exon one. We examined DNA samples from 101 patients with KD and 187 ethnically matched controls. No statistically significant differences in TGF beta 2 genotype or allele frequency distribution were observed between the patients and the controls. We believe this to be the first report of a case-control association study in KD and TGF beta 2 polymorphisms.     

Blocking transforming growth factor- receptor signaling down-regulates transforming growth factor-β1 autoproduction in keloid fibroblasts

Objective: To study transforming growth factor-β1(TGF-β1) autoproduction in keloid fibroblasts and theregulation effect of blocking TGF-β intracellular signalingon rhTGF-β1 autoproduction.Methods: Keloid fibroblasts cultured in vitro weretreated with either rhTGF-β1 (5 ng/ml ) or recombinantadenovirus containing a truncated type II TGF-β receptorgene (50 pfu/cell ). Their effects of regulating geneexpression of TGF-β1 and its receptor I and II wereobserved with Northern blot.Results: rhTGF-β1 up-regulated the gene expressionof TGF-β1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated thegene expression of TGF-β1 and its receptor I, but notreceptor II.Conclusions: TGF-β1 autoproduction was observed inkeloid fibroblasts. Over-expression of the truncated TGF-βreceptor H decreased TGF-β1 autoproduction via blockingTGF-β receptor signaling.     

Blocking transforming growth factor-beta receptor signaling down-regulates transforming growth factor-beta1 autoproduction in keloid fibroblasts.

OBJECTIVE: To study transforming growth factor-beta1 (TGF-beta1) autoproduction in keloid fibroblasts and the regulation effect of blocking TGF-beta intracellular signaling on rhTGF-beta1 autoproduction. METHODS: Keloid fibroblasts cultured in vitro were treated with either rhTGF-beta1 (5 ng/ml) or recombinant adenovirus containing a truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects of regulating gene expression of TGF-beta1 and its receptor I and II were observed with Northern blot. RESULTS: rhTGF-beta1 up-regulated the gene expression of TGF-beta1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated the gene expression of TGF-beta1 and its receptor I, but not receptor II. CONCLUSIONS: TGF-beta1 autoproduction was observed in keloid fibroblasts. Over-expression of the truncated TGFbeta receptor II decreased TGF-beta1 autoproduction via blocking TGF-beta receptor signaling.     

Analysis of transforming growth factor beta receptor binding in embryonic, fetal, and adult rabbit fibroblasts

Adult wound repair traits including inflammation, fibroplasia, and collagen deposition are not seen at fetal wound sites. This observation raised questions about regulatory mechanisms extant in fetal healing. Transforming growth factor beta (TGF-beta) is an important regulatory polypeptide known to orchestrate fibroplasia and collagen synthesis during adult wound repair. Previous studies have suggested that the wounded rabbit fetus is capable of responding with these adult characteristics if provided with exogenous TGF-beta. In order to test whether the observed in vivo effects of TGF-beta in the rabbit fetus might be due to a direct effect on the fibroblast, TGF-beta receptor binding characteristics of early passage cultured embryonic (14 days' gestation), fetal (24 days' gestation), and adult rabbit fibroblasts were studied by flow cytometry. Experiments were carried out using fluorescein-conjugated TGF-beta (F-TGF-beta) with analysis on an EPICS V flow cytometer. F-TGF-beta was incubated with each of the three fibroblast types at 37 degrees C after which time the cells were washed twice and analyzed with a minimum of 10(5) cells for each data point. F-TGF-beta bound rapidly and reversibly to the embryonic, fetal, and adult fibroblasts with saturation being achieved at 1 nmol/L for fetal and adult cells, and 8 nmol/L in the embryonic fibroblasts. Saturating concentrations of F-TGF-beta yielded mean channel numbers (a function of relative amounts of F-TGF-beta-bound) of 172, 114, and 97 for embryonic, fetal, and adult cells, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Differential use of Erk1/2 and transforming growth factor beta pathways by mid- and late-gestational murine fibroblasts

Background

Previously, we demonstrated the rapid closure of mid-gestational excisional murine wounds at 32 hours. In this study, we theorized that mid-gestational wounds would be completely regenerated, whereas late-gestational wounds would heal with scar formation at 48 hours. Furthermore, we theorized that mid- and late-gestational fibroblasts differentially use the transforming growth factor β and mitogen-activated protein kinase pathways.

Methods

Three-millimeter excisional cutaneous wounds were made on murine mid- (embryonic day 15 [E15]) and late-gestational (E18) fetuses and harvested at 48 hours for histology. Percent wound closure was calculated. E15 and E18 fibroblasts were cultured overnight for in vitro scratch wound assay in the presence of the activin receptor-like kinase 4-5-7, Erk1/2, and p38 inhibitors.

Results

E15 wounds healed in a regenerative manner, whereas E18 wounds exhibited scar formation. In vitro scratch closure was similar in the E15 and E18 groups at 8 hours; yet, it increased in E15 compared with E18 groups with activin receptor-like kinase 4-5-7 and Erk1/2 inhibitors. p38 inhibition resulted in reduced scratch closure in both groups.

Conclusion

The scarless mid-gestational excisional wounds compared with the scar-forming late-gestational wounds provides a model to study scar formation. This study also suggests that variable transforming growth factor β and Erk1/2 signaling may influence differences in wound closure between mid- and late-gestational wounds.     

Effect of fluvastatin on transforming growth factor beta 1 expression in peritoneal dialysis rats model

ObjectiveTo investigate the effect of fluvastatin on TGF-β1 expression in a rat model of peritoneal dialysis(PD). MethodsA rat model of PD was built by intraperitoneal injection of 2.5% or 4.25% peritoneal dialysate. SD rats were randomly divided into 7 groups: (1) Normal control group; (2)Saline control group: saline 100 ml/kg intraperitoneal injection(IP) each day; (3) Fluvastatin treatment group: fluvastatin intragastrically administration 10 mg/kg each day; (4) 2.5% PD group: 2.5% peritoneal dialysate IP 100 ml/kg everyday; (5)4.25% PD group: 4.25% peritoneal dialysate IP 100 ml/kg everyday; (6)2.5% PD plus fluvastatin treatment group: 2.5% peritoneal dialysate IP 100 ml/kg plus fluvastatin 10 mg/kg everyday; (7)4.25% PD plus fluvastatin treatment group: 4.25% peritoneal dialysate IP 100 ml/kg plus fluvastatin 10 mg/kg everyday. The rats were sacrificed at 6 weeks and peritoneal tissues were dissected. The expressions of TGF-β1 and FN were examined by RT-PCR and immunohistochemical analysis. Masson staining was used for histological examination. ResultsMasson staining showed that the peritoneum thickened in 2.5% and 4.25% PD group than in normal control group and saline control group. The fluvastatin treatment ameliorated the thickening of peritoneum induced by PD. RT-PCR and immunohistochemical analysis showed that the mRNA and protein expression of TGF- β1 and FN increased in 2.5% and 4.25% PD group than in normal and saline control group (all P＜0.05). The fluvastatin treatment ameliorated the increased expression of TGF-β1 and FN induced by PD. There was no statistically significant difference among normal control group, saline control group and fluvastatin treatment group in both peritoneal thickness and the expression of TGF-β1 and FN. ConclusionFluvastatin can reduce the increased expressions of TGF -β1 and FN in rat peritoneum and ameliorate the thickening of peritoneum induced by PD.     

γ干扰素对瘢痕疙瘩成纤维细胞转化生长因子β/Smad信号通路的作用

目的 了解γ干扰素(IFN-γ)对瘢痕疙瘩Fh(KFb)中TGF-β/Smad信号通路的作用,探讨IFN一γ治疗病理性搬痕的可能机制. 方法 切取3例患者的瘢痕组织,体外分离培养KFb,实验选用第3～5代细胞.(1)将KFb分为:对照组,加无血清DMEM培养;TGF-β_1组,用10 ng/mL的TGF-β_1单独作用;IFN-γ组,用100 ng/mL的IFN-γ单独作用;TGF-β_1+IFN-γ组,10 ng/mL的TGF-β_1与100 nS/mL的IFN-γ联合作用.采用实时荧光定量RT-PCR、蛋白质印迹法和免疫荧光细胞化学染色法,分别检测结缔组织生长因子(CTGF)的mRNA、蛋白表达,以及α平滑肌肌动蛋白(α-SMA)的蛋白表达与阳性细胞表达情况.(2)另取KFb,用10 ng/mL的IFN-γ作用,于作用前及作用后30 min和1、2、4、6、8 h通过实时荧光定量RT-PCR检测Smad 3和Smad 7的mRNA表达,于作用前及作用后1、2、4、6、8 h用蛋白质印迹法检测Smad 3和Smad 7的蛋白表达.(3)另取KFb,根据添加的IFN-γ终浓度不同分为1、10、100 ns/mL IFN-γ组,均作用4 h;设立未添加IFN-γ的KFb为对照组.同前检测各组Smad 3和Smad 7的mRNA及蛋白表达. 结果 (1)IFN-γ组KFb CTGF的mRNA和蛋白表达量为0.017±0.009与1.198±0.004,较对照组(0.024±0.013与1.229±0.011)显著减少(P<0.05);TGF-β1+IFN-γ组CTGF的mRNA和蛋白表达量为0.634±0.138与1.204±0.010,较TGF-β_1组(1.331±0.298与1.727±0.004)显著减少(P<0.01).IFN-γ组KFb中,α-SMA阳性细胞荧光强度(0.922±0.059)和α-SMA蛋白表达量(0.3051±0.0031)较对照组(1.055±0.005与0.4513±0.0094)显著减少(P<0.01);TGF-β1+IFN-γ组SMA阳性KFb荧光强度(1.129±0.004)和SMA蛋白表达量(0.6734±0.0098)较TGF-β_1组(1.270±0.005与1.38420.0024)显著减少(P<0.01).(2)10 ng/mL IFN-γ作用后第1个时相点,Smad 3的mRNA和蛋白表达量均出现一过性增高,随后降低,mRNA表达量于作用后4 h降至最低点,随后缓慢上升,至作用后8 h仍低于作用前(P<0.01);其蛋白表达量于作用后2~8 h显著低于作用前(P<0.01).而Smad 7的mRNA和蛋白表达量在INF-γ作用后逐渐增高,分别于作用后2、4 h达峰值随后降低,至作用后8 h仍高于作用前(P<0.05).(3)与对照组比较,1、10、100 ng/mL IFN-γ组Smad 3的mRNA及蛋白表达量显著减少(P<0.05或P<0.01),Smad 7的mRNA及蛋白表达量显著增加(P<0.05或P<0.01),且随IFN-γ浓度升高,减少或增高幅度愈为显著. 结论 IFN-γ呈时间和剂量依赖方式下调Smad 3、上调Smad 7,降低基础状态下或经TGF-β_1诱导后KFb的CTGF和α-SMA表达量,表现出对TGF-β/Smad 信号通路的显著拮抗作用,这可能是IFN-γ治疗病理性瘢痕的重要机制.     

Effect of heparin on production of transforming growth factor (TGF)-beta1 and TGF-beta1 mRNA expression by human normal skin and hyperplastic scar fibroblasts

Heparin affects both dermal fibroblast proliferation and collagen and may mediate these effects by altering the levels of transforming growth factor-beta1 (TGF-beta1) production and TGF-beta1 mRNA expression as a wound healing modulator. The purpose of this study is to probe the effect of heparin on TGF-beta1 and TGF-beta1 mRNA production by human normal skin and hyperplastic scar fibroblasts. This research investigates the effect of heparin on TGF-beta1 and TGF-beta1 mRNA production by human normal skin and hyperplastic scar fibroblasts with exposure to 0 microg/mL, 100 microg/mL, 300 microg/mL, or 600 microg/mL heparin for 24, 48, 72, or 96 hours in a serum-free in vitro model. Levels of TGF-beta1 in the supernatants and TGF-beta1 mRNA expression of fibroblasts were determined by enzyme-linked immunosorbent assay (ELISA) and real time RT-PCR, respectively. Heparin (300 microg/mL and 600 microg/mL) stimulated TGF-beta1 production by normal skin (26% to 83%) and hyperplastic scar fibroblasts (63% to 85%), with statistical significance (P < 0.05) at various time points. Heparin (300 microg/mL and 600 microg/mL) also stimulated TGF-beta1 mRNA expression by normal skin (12% to 53%) and hyperplastic scar fibroblasts (33% to 52%), with statistical significance (P < 0.05) at various time points. These effects of heparin on normal skin and hyperplastic scar fibroblasts may have implications for hyperplastic scar formation and wound healing in vivo.     

Effect of transforming growth factor beta and basic fibroblast growth factor on steroid-impaired healing intestinal wounds.

A longitudinal intestinal wound model in the pig was used to assess the effect of parenteral steroids (betamethasone 12 mg 50 kg-1 intramuscularly twice daily) on breaking load. Steroid treatment significantly decreased the breaking load of wounds in the ileum and colon in comparison with wounds from saline-treated animals. In a further group of animals receiving steroids, paired longitudinal wounds were constructed. One wound of a pair was treated with a local application of transforming growth factor beta (TGF-beta) (5 micrograms per wound) or basic fibroblast growth factor (5 micrograms per wound) in a collagen suspension. The other wound was treated with a collagen suspension alone. Ileal wounds treated with TGF-beta were significantly stronger than collagen-treated controls at 7 days. The steroid-induced impairment of breaking load in intestinal wounds is partially reversed by a local application of TGF-beta in a collagen suspension at the time of surgery.     

Insulin-like growth factor-1 suppresses pyrophosphate elaboration by transforming growth factor beta1-stimulated chondrocytes and cartilage

Our objective was to examine the effect of insulin-like growth factor-1 (IGF-1) on extracellular pyrophosphate (ePPi) elaboration by porcine cartilage. These studies further define the factors influencing ePPi accrual, a key step in calcium pyrophosphate dihydrate (CPPD) crystal formation. ePPi was measured in adult porcine organ and monolayer culture media in the presence of IGF-1, transforming growth factor beta-1 (TGFbeta-1), IGF-1 antibody and synovial fluid (SF). As previously shown, TGFbeta-1 stimulated ePPi elaboration by cartilage and chondrocytes. IGF-1 significantly inhibited the stimulatory effect of TGFbeta-1 on ePPi elaboration by both cartilage explants and chondrocytes. Anti-IGF-1 antibody blocked this inhibition. Anti-IGF-1 antibody also decreased the inhibitory effect of SF on ePPi elaboration, suggesting the presence of active IGF-1. These results support an important regulatory role for IGF-1 in cartilage ePPi elaboration. IGF-1 inhibited the effects of the ePPi-stimulatory factor TGFbeta-1 and thus may protect normal joints from excess accumulation of ePPi and subsequent CPPD crystal formation.     

Polymorphisms in the transforming growth factor beta 1 gene and osteoporosis

Transforming growth factor (TGF)-beta1 is the most abundant growth factor in human bone. It is produced by osteoblasts and inhibits osteoclast proliferation and activity and stimulates proliferation and differentiation of preosteoblasts. Several polymorphisms have been described in the TGF-beta1 gene. Previously, we and others have found associations between some of these polymorphisms and bone mass. We therefore wanted to examine if these polymorphisms are also predictors of osteoporotic fractures. The polymorphisms G(-1639)-A, C(-1348)-T, C(-765)insC, T(29)-C, G(74)-C, 713-8delC, C(788)-T, and T(816-20)-C were examined using RFLP and sequencing in 296 osteoporotic patients with vertebral fractures and 330 normal individuals. Bone mineral density (BMD) was examined at the lumbar spine and at the femoral neck by DXA. Genotype distributions were in H-W equilibrium. Linkage disequilibrium was found between the polymorphisms. The T(816-20)-C genotypes were distributed differently among osteoporotic patients and normal controls. The TT genotype was less common in individuals with osteoporotic fractures (chi(2) = 6.02, P < 0.05). BMD was higher in individuals with the TT-genotype (T(816-20)-C) at the lumbar spine, 0.960 +/- 0.173 g/cm(2) compared with individuals with the TC or CC genotypes: 0.849 +/- 0.181 g/cm(2) and 0.876 +/- 0.179 g/cm(2), respectively (P < 0.001, ANOVA). Similar differences between genotypes were found at the different hip regions as well as at the total hip. Individuals with the TT-genotype (C(-1348)-T) had higher bone mass at the femoral neck: 0.743 +/- 0.134 g/cm(2) compared with 0.703 +/- 0.119 g/cm(2) in individuals with TC or CC genotypes (P < 0.05). Individuals with the CC-genotype (T(29)-C) had higher bone mass at the femoral neck, 0.735 +/- 0.128 g/cm(2) compared with 0.703 +/- 0.120 g/cm(2) in individuals with TC or TT genotypes (P < 0.05) and at the total hip: 0.852 +/- 0.166 g/cm(2) vs. 0.818 +/- 0.149 g/cm(2), respectively (P < 0.05). None of the other polymorphisms were distributed differently in patients and controls and did not affect BMD. In conclusion, The TT genotype of the T(816-20)-C polymorphism is less common in patients with osteoporotic fractures and is associated with higher bone mass both at the lumbar spine and at the hip. The C(-1348)-T and T(29)-C polymorphisms were distributed similarly in osteoporotic patients and normal controls, however, the rare genotypes were associated with higher bone mass at the hip.     

Transforming growth factor beta (TGFbeta) and keloid disease

Keloids are benign fibroproliferative diseases of unknown aetiology. They occur as a result of derangement of the normal wound healing process in susceptible individuals. Although several factors have been postulated in the aetiopathogenesis of this condition, there has been growing evidence to suggest a role for Transforming Growth Factor beta (TGFbeta) family members in its pathogenesis. TGFbeta has also been found to be associated with fibrotic diseases affecting different organs of the body including liver, kidney, lung as well as skin. In this review article, we will discuss the morphology and mechanism of action of TGFbeta and its isoforms and present the most up to date literature discussing the role of TGFbeta isoforms, their receptors, and intracellular signalling pathways (the SMAD pathway) in the pathogenesis of keloid disease. Understanding the role of TGFbeta in keloid disease could lead to the development of clinically useful therapeutic modalities for treatment of this condition.     

转化生长因子-β1反义RNA腺病毒载体的构建

目的构建含转化生长因子β1(TGF-β1)反义RNA的重组腺病毒重组体。方法将TGF-β1的cDNA5＇端630bp片段反向插入穿梭载体pAdTraek-CMV,构建为TGF-β1反义RNA的重组体(pAdTrack-antiTGFβ1),将重组体pAdTrack-antiTGFβ1与包装质粒pAdEasy-1共转染BJ5183细菌。用选择培养基筛选同源重组的阳性克隆,同源重组的腺病毒载体转染293细胞,在荧光显微镜下观察细胞中的绿色荧光蛋白(GFP)及PCR扩增目的基因等方法鉴定重组的腺病毒。结果构建了含rGF-β1反义RNA的重组腺病毒,其滴度为2.4×10     

转化生长因子β1诱导肌纤维母细胞分化机制的研究

目的 探讨肺移植后闭塞性细支气管炎中转化生长因子β1（TGF-β1）诱导肌纤维母细胞分化的机制。方法 闭塞性细支气管炎动物模型采用Smad3野生型和基因敲除小鼠进行的同种异体异位气管移植,并采用原代培养的气管纤维母细胞,通过免疫组化、免疫荧光、Western Blotting、逆转录聚合酶链反应和DNA凝胶电泳迁移率检测等手段,检测肌纤维母细胞分化的标志物α平滑肌肌动蛋白（αSMA）的表达,以及Smad3、p38和ERK1／2的激活。结果 在闭塞性细支气管炎的受累气道中,发现有αSMA的大量表达。对纤维母细胞进行的离体研究,发现TGF-β1诱导Smad3激活,表现为蛋白磷酸化、细胞核转位和DNA结合。TGF-β1引起肌纤维母细胞分化增加,表现为αSMA在转录和蛋白水平的表达增加;而在缺乏Smad3的纤维母细胞中,TGF-β1诱导的肌纤维母细胞分化明显减少（t=2,080,P=0．027;t=1．982,P=0．032）,但未完全消除。TGF-β1可通过激活p38和ERK1／2来促进少量肌纤维母细胞的分化。结论 TGF-β1可通过激活Smad3依赖性和非依赖性信号传导途径,主要是Smad3依赖性途径,来促使纤维母细胞向肌纤维母细胞的转化,最终导致闭塞性细支气管炎的发展。     

In vivo induction of bone by recombinant human transforming growth factor beta 1.

A single application of recombinant human transforming growth factor beta 1 (rhTGF-beta 1) adjacent to cartilage was found to induce bone formation in rabbit ear full-thickness skin wounds. At doses that optimally promote soft tissue healing, 25-100 ng rhTGF-beta 1 per wound caused osseous tissue formation starting 21 days after wounding to reach a peak incidence and area of bone formation at day 42. Bone formation was followed by active remodeling, resulting in lower incidence and area of bone formation at days 56 and 70. The early phase of bone formation was located overlying the cartilage and involved perichondrial cells that appeared to differentiate directly into osteoblasts forming bone matrix without a cartilage precursor. Cartilage was replaced with bone at later time points. rhTGF-beta 1 was able to increase the ratio of osteoblasts to osteoclasts lining the trabecular surface of bone and thus increase the net amount of bone formation. The present studies suggest a potential therapeutic role for rhTGF-beta 1 in hard tissue repair.     

Effect of transforming growth factor beta on postoperative adhesion formation and intact peritoneum.

Transforming growth factor beta (TGF beta) is an extremely potent chemoattractant for macrophages, mononuclear leukocytes, and fibroblasts. It also acts as a potent stimulant for collagen and fibronectin synthesis and inhibits epithelial cell growth. TGF beta plays an important role in healing many types of wounds, but its role in peritoneal adhesion formation is not known. These studies were performed to determine if TGF beta could affect postoperative wound healing in a rat model. In the first experiment, 20 rats were divided into two groups and received either 2 micrograms TGF beta or control diluent IP daily for 5 days after surgical injury to the uterine horns. The severity of the adhesions were graded 2 weeks postoperatively using a score of 0-3. The TGF beta group showed a higher adhesion score at 2 weeks compared to control, 2.9 +/- 0.34 and 1.6 +/- 0.61, respectively (P less than 0.001). On H&E stained sections of the adhesions, there was an increase in the number of both inflammatory cells and fibroblasts in the TGF beta-treated animals. A comparison trial of bone-derived TGF beta (a gift from Collagen Corporation, Palo Alto, CA) versus recombinant TGF beta (a gift from Oncogen, Seattle, WA) versus control using the same protocol as above showed that both sources of TGF beta were more effective in promoting postoperative adhesions when compared to controls, and there was no difference between TGF beta groups, 3.0 +/- 0 for both TGF beta groups, and 2.2 +/- 0.91 for control (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Localization of transforming growth factors beta1 and beta2 and epidermal growth factor in IgA nephropathy.

OBJECTIVE: The localization of transforming growth factor (TGF)-beta1. TGF-beta2 and epidermal growth factor (EGF) was investigated in IgA nephropathy, and was compared with the severity of histological damage (including tubulointerstitial lesions). MATERIALS AND METHODS: The enzyme antibody method was used to stain paraffin-embedded sections of renal tissue from 42 patients with IgA nephropathy (19 males and 23 females). Results: There was a significant correlation between glomerular positivity for TGF-beta1 and TGF-beta2 and the severity of histological damage. There was also a significant correlation between positivity for TGF-beta1 and TGF-beta2 in the tubular epithelium and tubulointerstitial lesions. In contrast, there was no relationship between glomerular positivity for EGF and histological damage, although there was a significant correlation between positivity for EGF in the tubular epithelium and tubulointerstitial lesions. Conclusions: These findings suggest that TGF-beta1 and TGF-beta2 may be important in the progression of IgA nephropathy, and that the distribution of EGF may also be a useful marker for the progression of renal damage, including tubulointerstitial lesions.     

Verapamil inhibits interleukin-6 and vascular endothelial growth factor production in primary cultures of keloid fibroblasts.

An increased secretion of cytokines and growth factors has been hypothesised to play a role in the abnormal growth of keloid fibroblasts. The aim of this study was to evaluate the effect of the calcium antagonist verapamil on the interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion, as well as on cellular growth, in primary cultures of fibroblasts derived from the central part of keloid lesions. These cells grew faster than peripheral keloid and nonkeloid fibroblasts, and, in long-term cultures, became stratified assuming a three-dimensional structure. Compared with peripheral and nonkeloid fibroblasts, central keloid fibroblasts presented an increased production of both IL-6 and VEGF (P<0.03 and P<0.005, respectively). Verapamil (100 microM) decreased IL-6 and VEGF production (P<0.03 and P<0.005, respectively) in central keloid fibroblasts cultures at 72 h. Moreover, verapamil decreased cellular proliferation by 29% and increased apoptosis to an absolute value of 8%. The results of this study demonstrate that in primary cultures of central keloid fibroblasts verapamil reduces the sustained basal IL-6 and VEGF production and inhibits cell growth; these data may offer the link with the beneficial effect of calcium antagonists on keloid scars in vivo.