Reduced expression of mRNA for transforming growth factor beta (TGF beta) and TGF beta receptors I and II and decreased TGF beta binding to the receptors in in vitro-aged fibroblasts

The combination of cigarette smoke and solar rays causes effects similar to skin aging in a bilayer skin model

Skin aging is a multifactorial process influenced by internal and external factors. The contribution of different environmental factors has been well established individually in the last few years. On the one hand, man is rarely exposed to a single factor, and on the other hand, there is very little knowledge about how these extrinsic factors may interact with each other or even how the skin may react to chronic exposure. This study aimed to evaluate the effect on skin aging of a chronic co-exposure of tissue-engineered skin substitutes to cigarette smoke extract (CSE) and solar simulator light (SSL). Skin substitutes were reconstructed according to the self-assembly method and then exposed to CSE followed by irradiation with SSL simultaneously transmitting UVA1, visible light and infrared. When skin substitutes were chronically exposed to CSE and SSL, a significant decrease in procollagen I synthesis and the inhibition of Smad2 phosphorylation of the TGF-β signaling pathway were observed. A 6.7-fold increase in MMP-1 activity was also observed when CSE was combined with SSL, resulting in a decrease in collagen III and collagen IV protein expression. The secretory profile resulting from the toxic synergy was investigated and several alterations were observed, notably an increase in the quantities of pro-inflammatory cytokines. The results also revealed the activation of the ERK1/2 (3.4-fold) and JNK (3.3-fold) pathways. Taken together, the results showed that a synergy between the two environmental factors could provoke premature skin aging.

Platelet-Rich Plasma in Aesthetics

Platelet-rich plasma (PRP) is being used as a treatment modality for skin rejuvenation since the last decade. There has been a lot of ambiguity regarding the ideal protocol to be followed and the specific indications where its use should be promoted. The use of PRP as monotherapy for skin rejuvenation, acne scars, periorbital rejuvenation, lipofilling and in combination with fractional CO₂ and other resurfacing modalities is increasing rapidly. In this article, we have reviewed the current scientific evidence available and the IADVL national task force for PRP has come up with standard recommendations for use of PRP in esthetics along with the grade of evidence and strength of recommendation for each indication. The aim of this review is to provide a standard protocol for use of PRP in esthetics, for clinicians and academicians, leading to excellent results with this promising treatment modality.

The long non-coding RNA FLJ46906 binds to the transcription factors NF-κB and AP-1 and regulates expression of aging-associated genes

Several features differentiate aged cells from young cells, many of which are due to changes in gene expression during the aging process. The mechanisms of altered gene expression in aging cells remain incompletely understood, and we hypothesized that long non-coding (lnc) RNAs mediate at least some of these changes. We screened for alterations in lncRNA expression with aging in skin fibroblasts and identified the lncRNA FLJ46906 to be consistently upregulated with aging in-vivo and in-vitro. The function of this lncRNA has not been known. Here we show that FLJ46906 regulates several aging-associated genes, including IL1B, IL6, CXCL8, TGFB1, and ELN. We suggest that these effects are mediated through NF-κB and AP-1, because these aging-associated genes are regulated by NF-κB and AP-1, and because we found that FLJ46906 directly binds to these two transcription factors. This data supports a role of the lncRNA FLJ46906 in the aging process.

Reduced matrix metalloproteinase and collagen transcription mediated by the TGF-β/Smad pathway in passaged normal human dermal fibroblasts

BACKGROUND

Transforming growth factor-β (TGF-β) is a major regulator of extracellular matrix (ECM) events, particularly collagen production.

AIM

We explored whether the expression of matrix metalloproteinases (MMPs) and collagen are transcriptionally regulated by the TGF-β and Smad signaling pathways, and the roles played by NF-κB and mitogen-activated protein kinase (MAPK) signaling in normal, aged, human dermal fibroblasts.

METHODS

We quantified mRNA and protein expression using real-time PCR and immunoblotting of proteins from cells in passage 5-15.

RESULTS

The levels of mRNAs encoding TGF-β1, TGF-β3, and TGF-β receptor type I (TGFβ RI) decreased with increasing passage number. The levels of mRNAs encoding TGF-β2, TGFβ RII, and TGFβ RIII increased to passage 10 but decreased by passage 15. The levels of mRNAs encoding Smad-2, -3, -4, and -7 decreased with increasing passage number. The level of mRNA encoding MMP-1 increased with increasing passage number, and the levels of mRNAs encoding MMP-2, TIMP-1, and TIMP-2 increased to passage 10 but decreased by passage 15. The levels of mRNAs encoding collagen types I and II decreased with increasing passage number. At the protein level, NF-κB, IκBα, p38, ERK, Akt, and JNK became increasingly phosphorylated at higher passage numbers.

CONCLUSION

Our results suggest that reductions in the expression levels of MMPs and collagen types I and III in aging human dermal fibroblasts reflect reduced expression of TGF-β/Smad and TGF-β receptors, thus compromising the TGF-β receptor-binding capacity of fibroblasts; the NF-κB and Akt-JNK/MAPK signaling pathways may play active roles in this process.

Problems and Solutions for Platelet-Rich Plasma in Facial Rejuvenation: A Systematic Review

BACKGROUND

In recent years, platelet-rich plasma (PRP) has been widely applied in orthopedics, maxillofacial surgery, burns, and plastic surgery, especially in facial rejuvenation. Research is ongoing into new indications and mechanisms of PRP to promote its wider, safer, and more effective use in the clinic. This article reviews the possible mechanisms of PRP in facial rejuvenation and related research. It is expected that the application of PRP in this field will increase.

METHODS

The use of PRP in facial rejuvenation was screened using inclusion and exclusion criteria. The relevant articles were searched through Pubmed digest database, SCI full-text database, ScienceDirect full-text database, and the CNKI full-text database. The different effects and limitations of PRP were extracted.

RESULTS

A total of 108 articles were obtained, including 18 articles researching PRP in cells, 10 articles on animal research using PRP, 16 articles on the clinical study of PRP, 24 articles involving signs of skin aging, and four articles on the limitations of PRP. The remaining articles were related to the preparation of PRP, the introduction of PRP, and other aspects.

CONCLUSION

Based on in vitro and in vivo research, PRP may play a role in promoting tissue regeneration, oxidative stress and revascularization, which form the theoretical basis for the use of PRP in the clinical treatment of facial rejuvenation.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Lasers, Microneedling, and Platelet-Rich Plasma for Skin Rejuvenation and Repair

Skin resurfacing for the purpose of rejuvenation and repair continues to evolve with the development of noninvasive or minimally invasive surgical substitutes. Advances in laser therapy, microneedling, and platelet-rich plasma have reinvigorated research in wound repair and regenerative science. An overall positive clinical response toward the use of platelet-rich plasma as an adjuvant to fractional photothermolysis and percutaneous collagen induction is observed. Its effect on post-treatment adverse symptoms, erythema, edema, crusting, and clinical outcomes in rejuvenation are summarized in this article. The lack of identifiable complications and convenience of treatment provides a positive outlook for future use and investigations.

TGF-beta-induced early gene-1 overexpression promotes oxidative stress protection and actin cytoskeleton rearrangement in human skin fibroblasts

BACKGROUND

Transforming growth factor beta inducible early gene-1 (TIEG-1), a member of the Krüppel-like factor, was identified as a primary response gene for TGF-β. The role of TIEG-1 in skin repair has been mainly addressed in vivo on TIEG-1 null mice model and the mechanism remains unexplored.

METHODS

We investigated the modulation of TIEG-1 expression in normal human skin fibroblasts by either down-expressing or overexpressing the gene. We evaluated reactive oxygen species production and the cell viability of treated cells. The effect of TIEG-1 overexpression was monitored by wound healing assay and immunofluorescence staining of actin fibers organization and alpha-smooth muscle actin (α-SMA). Western blots were carried out to identify the level of expression or phosphorylation of key proteins such as cofilin, Rho GTPases, and p38 mitogen-activated protein kinase (p38 MAPK).

RESULTS

TIEG-1 down-regulation had a deleterious effect on the cell viability. It was significantly reduced (65±5%) and exposure to ultraviolet further increased this effect (47±3%). By contrast, cells overexpressing TIEG-1 had a reduced reactive oxygen species production (75%) compared to control and mock-transfected cells. This overexpression also resulted in formation of actin stress fibers and increased α-SMA expression and an enhanced wound healing feature. RhoB GTPase was upregulated and phosphorylation of cofilin and p38 MAPK was observed.

CONCLUSION

TIEG-1 overexpression in normal human skin fibroblasts results in improved resistance to oxidative stress, myofibroblast-like conversion that involved RhoB signaling pathway with cofilin and p38 MAPK proteins activation.

GENERAL SIGNIFICANCE

This study enlightens the role of TIEG-1 role in skin biology.

Beneficial regulation of type I collagen and matrixmetalloproteinase-1 expression by estrogen, progesterone, and its combination in skin fibroblasts

There is impaired wound healing and loss of type I collagen in skin aging, which can be improved by topical estrogen in vivo. The goal of this study was to determine the effects of estrogen, and progesterone and a combination of estrogen and progesterone as well, on the proliferation and the expression of type I collagen and matrixmetalloprotienase-1 (MMP-1, degrades collagen) in dermal fibroblasts (cells that synthesize collagen and MMP-1) in-vitro. Estrogen, progesterone, and its combination similarly and significantly inhibited cell proliferation and MMP-1 protein levels, and simultaneously stimulated type I collagen expression in the fibroblasts, indicating beneficial modulation.

Tacrolimus abrogates TGF-β1-induced type I collagen production in normal human fibroblasts through suppressing p38MAPK signalling pathway: implications on treatment of chronic atopic dermatitis lesions

BACKGROUND

Atopic dermatitis (AD) is a commonly encountered inflammatory skin disease. Although acute lesions of acute AD are characterized by intense inflammation, the hallmarks of chronic AD lesions include lichenified fibrosis and thickening of the upper dermis. The increased expression of transforming growth factor beta 1 (TGF-β1), a well-known fibrogenic cytokine, is observed in chronic AD lesions. Tacrolimus (FK506) ointment has been reported to be effective for treating AD as well as some TGF-β1-induced fibrotic diseases.

OBJECTIVES

To evaluate the effect of tacrolimus on TGF-β1-stimulated cultured normal human dermal fibroblasts and explore the potential signalling pathways involved.

METHODS

Fibroblasts cultured from healthy adult human foreskins were treated with TGF-β1 with or without tacrolimus. The impact on cell viability and proliferation were assessed by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and BrdU incorporation assay respectively. Reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time PCR, enzyme-linked immunosorbent assay (ELISA) and western blotting were performed to evaluate the relevant expressions of mRNA or proteins in fibroblasts.

RESULTS

Our results revealed that the increased expressions of transforming growth factor-β receptor I (TGF-βRI) and TGF-βRII in TGF-β1-treated fibroblasts were suppressed by tacrolimus treatment. In addition, tacrolimus significantly inhibited fibroblast proliferation enhanced by TGF-β1. TGF-β1 increased type I collagen production, and this enhancing effect was suppressed by tacrolimus. The down-regulation of MMP-1 and up-regulation of TIMP-1 induced by TGF-β1 were reversed by tacrolimus. The increase in phosphorylated p38 mitogen-activated protein kinase (p38MAPK) expression stimulated by TGF-β1 was down-regulated by tacrolimus. Moreover, the fibroblasts treated with p38MAPK inhibitor significantly reduced type I collagen expression induced by TGF-β1.

CONCLUSIONS

The present results demonstrated that tacrolimus significantly inhibited physiological functions of fibroblasts enhanced by TGF-β1 in vitro. Clinically, we propose that topical tacrolimus may not only reduce AD recurrence but also ameliorate dermal fibrosis often seen in chronic AD lesions.

Beneficial regulation of fibrillar collagens, heat shock protein-47, elastin fiber components, transforming growth factor-β1, vascular endothelial growth factor and oxidative stress effects by copper in dermal fibroblasts

Skin aging is associated with the loss of the structural collagens and the elastin fiber components that form the extracellular matrix (ECM). It is associated with reduced transforming growth factor-β (TGF-β), angiogenesis and increased oxidative stress. Copper has been incorporated into cosmetics for anti-skin aging. This research investigated the mechanism for the anti-skin aging effect copper ions, from cuprous oxide powders. Dermal fibroblasts were exposed to copper and examined for expression (protein and/or promoter levels) of types I, III, V collagen, heat shock protein-47 (HSP-47), elastin, fibrillin-1, and fibrillin-2, TGF-β1, vascular endothelial growth factor (VEGF), and in addition for membrane damage and lipid peroxidation. The direct antioxidant activity of copper was also determined. The research indicates that copper's anti-skin aging and skin regeneration potential is through its stimulation of ECM proteins, TGF-β1, VEGF, and inhibition of oxidative stress effects at physiological concentrations; and supports its use in cosmetics.

[Molecular etiology of skin aging. How important is the genetic make-up?]

Although the fundamental mechanisms in the pathogenesis of skin aging are still poorly understood, a growing body of evidence points toward the involvement of multiple pathways. Recent data obtained by expression profiling studies and studies upon progeroid syndromes illustrate that among the most important biological processes involved in skin aging are alterations in DNA repair and stability, mitochondrial function, cell cycle and apoptosis, extracellular matrix, lipid synthesis, ubiquitin-induced proteolysis and cellular metabolism. One of the major factors which have been proposed to play an exquisite role in the initiation of aging is the physiological decline of hormones occurring with age. However, hormones at age-specific levels may not only regulate age-associated mechanisms but also modulate tumor suppressor pathways that influence carcinogenesis. In conclusion, understanding the molecular mechanisms of ageing may open new strategies to deal with the various diseases accompanying advanced age including cancer.

Clinical aspects and molecular diagnostics of skin aging

This contribution will address the effect of aging on skin functions, with a particular focus on skin permeability, wound healing, angiogenesis, lipogenesis, sweat production, immune function, and vitamin D synthesis. With accelerating age, skin functions deteriorate due to structural and morphologic changes. Skin is prone to the development of several diseases, varying from benign to malignant. Because the number of persons aged 80 and older is expected to rise in the next decades, disease prevention will become an important issue. Screening examinations and prevention through public education starting at an early age regarding sun avoidance, the use of sunscreens and the importance of a balanced nutrition are the first steps for successful healthy aging. Although the fundamental mechanisms in the pathogenesis of aged skin are still poorly understood, a growing body of evidence points toward the involvement of multiple pathways. Recent data obtained by expression profiling studies and studies of progeroid syndromes illustrate that among the most important biologic processes involved in skin aging are alterations in DNA repair and stability, mitochondrial function, cell cycle and apoptosis, extracellular matrix, lipid synthesis, ubiquitin-induced proteolysis and cellular metabolism. Among others, a major factor that has been implicated in the initiation of aging is the physiologic decline of hormones occurring with age. However, hormones at age-specific levels may regulate not only age-associated mechanisms but also tumor suppressor pathways that influence carcinogenesis. Understanding the molecular mechanisms of aging may open new strategies to deal with the various diseases accompanying high age, including cancer.

Regulation of matrix contraction in chronic venous disease

OBJECTIVE

The role of TGF-beta(1) in venous ulcer healing and the signalling cascades regulating dermal fibroblast function are poorly understood. To elucidate these processes, we hypothesized that TGF-beta(1) facilitates wound healing by increasing chronic venous insufficiency (CVI) induced matrix contraction via intracellular cross-talk between TGF-beta(1) and the ERK-1/2 MAP kinase signalling cascades.

METHODS

Fibroblasts isolated from calf biopsies (LC) of patients with different severity of CVI (CEAP, Clinical Etiological Anatomical Pathological classes) were seeded into 200 microl collagen gels under isometric conditions. Fibroblasts from neonatal foreskins (HS68), non-CVI patients (NC), and the ipsilateral normal thigh of each CVI patient (LT) served as controls. Thirteen patients with CVI (class 2, n=5; class 4, n=5; class 6, n=3) and 2 non-CVI controls (NC, n=2) were included in the study. All experimental conditions were determined by dose-response and time-course experiments. Gels were cultured with/without 0.1 ng/ml TGF-beta(1) and with/without 50 microM PD98059 (MEK and downstream-MAPK inhibitor). Additional patient fibroblasts were transfected with constitutively active Ras (pCMV-Ras) or an empty vector (pCMV-beta) with/without 0.1 ng/ml TGF-beta(1) and with/without 50 microm PD98059. The collagen gels were released after 4 days and the percent contraction was determined by area measurements using image analysis. Differences in alpha-smooth muscle actin (alpha-SMA) and ERK-1/2 MAPK (phosphorylated and total) protein levels were analyzed with western blotting.

RESULTS

Gels seeded with CVI fibroblasts contracted more than HS68, NC and LT fibroblasts. Inhibition of MAPK and/or stimulation with TGF-beta(1) increased the contraction of LC gels compared to unstimulated controls. Agonist induced gel contraction correlated with CVI disease severity. alpha-SMA protein expression in LC fibroblasts increased with MAPK inhibition with/without TGF-beta(1) stimulation, and correlated with the degree of gel contraction. Transfection with pCMV-Ras (activator of ERK-1/2) inhibited gel contraction; this inhibition was not reversed by addition of TGF-beta(1). Transfection with the pCMV-beta empty vector had no effect on gel contraction.

CONCLUSIONS

TGF-beta1 stimulation of CVI patient fibroblasts grown in 3D collagen gels results in conversion to a contractile phenotype through upregulation of alpha-SMA, and in enhanced gel contraction. Inhibition of MAPK further increases gel contraction, while Ras activation of ERK-1/2 inhibits TGF-beta1-induced gel contraction. These responses correlate with increasing CEAP severity. CVI fibroblast mediated gel contraction is therefore regulated through cross-talk between the ERK-1/2 MAPK and TGF-beta(1) signalling cascades. These data identify potentially clinically relevant therapeutic molecular targets that could enhance matrix contraction and thereby improve venous ulcer wound healing.

Beneficial regulation of matrixmetalloproteinases and their inhibitors, fibrillar collagens and transforming growth factor-beta by Polypodium leucotomos, directly or in dermal fibroblasts, ultraviolet radiated fibroblasts, and melanoma cells

The extracellular matrix (ECM) that gives tissue its structural integrity is remodeled in skin aging/photoaging and cancer via the increased expression/activities of matrixmetalloproteinases (MMP), inhibition of the tissue inhibitors of matrix metalloproteinases (TIMP), or inhibition of collagen synthesis. Transforming growth factor-beta (TGF-beta), a predominant regulator of the ECM, is inhibited in aging/photoaging and stimulated in carcinogenesis. P. leucotomos (fern) extract has potential to counteract these alterations via its antioxidant, anti-inflammatory and photoprotective properties. The goal of this research was to determine the efficacy of P. leucotomos to (a) directly inhibit MMP-1, 2, 3, and 9 activities, (b) inhibit MMP-2, and stimulate TIMPs, fibrillar collagens and TGF-beta in non-irradiated or ultraviolet (UV) radiated fibroblasts, and (c) inhibit MMPs and TGF-beta, and stimulate TIMPs in melanoma cells. To this purpose, we examined the direct effect of P. leucotomos (0-1%) on MMPs' activities, and its effects on the expression (protein and/or transcription levels) of (1) MMPs and TIMPs in dermal fibroblasts, and melanoma cells, (2) TGF-beta in non-irradiated, UVA (2.5 J/cm2) or UVB (2.5 mJ/cm2) irradiated fibroblasts, and melanoma cells, and (3) types I, III, and V collagen in non-irradiated or UV irradiated fibroblasts. P. leucotomos directly inhibited the activities of MMPs as well as the expression of MMPs in fibroblasts, and melanoma cells while stimulating the expression of TIMPs in these cells. P. leucotomos stimulated types I, III, and V collagen in non-irradiated fibroblasts, and types I and V collagen in UV radiated fibroblasts. P. leucotomos had predominant stimulatory effects on TGF-beta expression in non-irradiated or UV radiated fibroblasts, and inhibited TGF-beta expression in melanoma cells. The effects of P. leucotomos were largely similar to that of ascorbic acid. P. leucotomos demonstrated dual protective effects on the ECM via its inhibition of the ECM proteolytic enzymes and the stimulation of the structural ECM collagens. The effects of P. leucotomos on fibroblasts and melanoma cells may be partly via its cell-specific regulation of TGF-beta expression and partly via its antioxidant property. The intake or topical application of P. leucotomos may be beneficial to skin health, in aging and cancer prevention or treatment.

Increased levels of a particular phosphatidylcholine species in senescent human dermal fibroblasts in vitro

Plasma membranes are essential components of living cells, and phospholipids are major components of cellular membranes. Here, we used liquid chromatography/mass spectrometry to investigate changes in the membrane phospholipid content that occur in association with aging. Our results indicate that the levels of a particular species of phosphatidylcholine comprised of stearic acid and arachidonic acid increased with age. To determine the reason for the increased levels of this particular phosphatidylcholine, we examined the effect of highly unsaturated fatty acids, such as arachidonic acid and eicosapentaenoic acid, on cellular aging. Applied arachidonic acid was incorporated into phosphatidylcholine molecules, but neither arachidonic acid nor other related unsaturated fatty acids had any effect. We conclude that increased levels of this distinctive phosphatidylcholine are a result of in vitro senescence.

William J. Cunliffe Scientific Awards. Characteristics and pathomechanisms of endogenously aged skin

The skin, being in direct contact with several environmental factors (e.g. UV irradiation), does not only undergo endogenous aging, which has to do with the 'biological clock' of the skin cells per se, but also exogenous aging. While exogenous skin aging has been extensively studied, the pathomechanisms of endogenous skin aging remain far less clear. Endogenous skin aging reflects reduction processes, which are common in internal organs. These processes include cellular senescence and decreased proliferative capacity, decrease in cellular DNA repair capacity and chromosomal abnormalities, loss of telomeres, point mutations of extranuclear mtDNA, oxidative stress and gene mutations. As a consequence, aged skin in nonexposed areas shows typical characteristics including fine wrinkles, dryness, sallowness and loss of elasticity. Recent data have illustrated that lack of hormones occurring with age may also contribute to the aging phenotype. Improvement of epidermal skin moisture, elasticity and skin thickness, enhanced production of surface lipids, reduction of wrinkle depth, restoration of collagen fibers and increase of the collagen III/I ratio have been reported after hormone replacement therapy or local estrogen treatment in postmenopausal women. Furthermore, an in vitro model of endogenous skin aging consisting of human SZ95 sebocytes which were incubated under a hormone-substituted environment illustrated that hormones at age- and sex-specific levels were able to alter the development of cells by regulating their transcriptome. In conclusion, among other factors the hormone environment plays a distinct role in the generation of aged skin.

Topical application of 17beta-estradiol increases extracellular matrix protein synthesis by stimulating tgf-Beta signaling in aged human skin in vivo

To investigate the effects of topically applied 17beta-estradiol on the expression of extracellular matrix proteins in aged human skin, 17beta-estradiol (0.01%) and its vehicle (70% propylene glycol, 30% ethanol) were applied to aged (68-82 y, eight females and five males) human buttock skin under occlusion for 2 wk (three times per week). Topical 17beta-estradiol was found to increase the expression of type 1 procollagen mRNA and protein significantly in human aged skin in vivo. In addition, metalloproteinase (MMP-1 protein levels were reduced by topical 17beta-estradiol. The expressions of TGF-beta1, TGF-beta type II receptor, and Sma and Mad related (Smad)3 were increased by topical 17 beta-estradiol in aged human skin, and TGF-beta1 neutralizing antibody inhibited 17beta-estradiol-induced procollagen synthesis in cultured fibroblasts. We also found that the expressions of tropoelastin and fibrillin-1 mRNA and protein, and elastic fibers in aged skin were also increased by topical 17beta-estradiol. Topical 17beta-estradiol also increased keratinocyte proliferation and the epidermal thickness in aged human skin. We also observed the same effects of topical 17beta-estradiol in young skin. In conclusion, our results suggest that topical 17beta-estradiol treatment may improve the cutaneous function of aged human skin by improving the connective tissue and increasing epidermal thickness.

Acrogeria with decreased gene expression of alpha1 (I) and alpha1 (III) collagen in cultured dermal fibroblasts

We report a case of acrogeria. A 47-year-old Japanese man presented with micrognathism, thin lips, radial wrinkles around his month, atrophy of skin and subcutaneous tissue, and mottled hyperpigmentation on his extremities. A biopsy of the lesional skin showed flat epidermis and atrophy of the dermal layer. The in vitro life span of the patient's fibroblasts (18+/-2.2 PDL) was significantly shorter than that of control fibroblasts (42+/-3.5 PDL). The early-passage fibroblasts from the patient showed abnormal morphology which was also seen in the late-passage (in vitro aging) of normal fibroblasts. In northern blotting analysis of cultured dermal fibroblasts, mRNA levels of alpha1 (I) collagen and alpha1 (III) collagen were markedly reduced. These results revealed that patient fibroblasts might be in severe senescence in vitro and contribute to the phenotypes of this premature aging syndrome.

Mitochondrial redox control of matrix metalloproteinases

Reactive oxygen species (ROS) are constantly generated in aerobic organisms during normal metabolism and in response to both internal and external stimuli. Imbalances in the production and removal of ROS have been hypothesized to play a causative role in numerous disease pathologies such as cancer, ischemia/reperfusion injury, and degenerative diseases such as photoaging, atherosclerosis, arthritis, and neurodegeneration. A feature often associated with these diseases is a malfunctioning of the connective tissue remodeling process due to increased activity of extracellular matrix-degrading metalloproteinases (MMPs). This review summarizes the evidence that implicates ROS as key regulators of MMP production and the importance of these interactions in disease pathologies.

Transforming growth factor-beta receptor-II up-regulation during wound healing in previously irradiated graft beds in vivo

Wound healing disorders may often present in patients with head and neck cancer after surgical interventions, particularly in preirradiated tissue. Inflammatory changes and the expression of cytokines can lead to induction of fibrosis. The isoforms of the transforming growth factor beta (TGFbeta1-3) play a key role for this process. It has been shown that radiation treatment associated fibrosis is induced by TGFbeta1 and TGFbeta2, although the influence of radiation on the expression of the TGFbeta receptor-II (TGFbetaR-II) involved in the signal transduction of TGFbeta remains elusive. The objective of this in vivo study was to analyze the expression profile of TGFbetaR-II in the graft bed and in the transition area between graft and graft bed after surgery with and without prior radiation treatment to compare with the expression profiles of activated TGFbeta1 and latency-associated peptide. A total of 48 Wistar rats (male, weight 300-500 g) were used in the study. Eighteen rats were irradiated in the neck region (3 x 10 Gy) without transplantation. A free myocutaneous gracilis flap was transplanted in 30 rats, of which 16 animals were preirradiated in the neck region (3 x 10 Gy) and 14 animals were not irradiated at all. Tissue samples were taken postoperatively from the transition area between the graft and the graft bed and from the graft bed itself after 3, 7, 14, and 28 days. Tissue samples were taken from the irradiated neck region and the non-irradiated groin region 0, 4, 7, 11, 14, and 28 days after the end of the exposure. The expression of TGFbetaR-II, activated TGFbeta1 and latency-associated peptide was analyzed immunohistochemically both qualitatively and quantitatively (labeling index). The success rate for graft healing was 75% in the previously irradiated group with 30 Gy, and 86% in the non-irradiated group. Following radiation alone a significantly (p = 0.04) increased TGFbetaR-II expression in the neck was revealed 2-4 weeks following irradiation compared to non-irradiated skin. Whereas only minor differences in TGFbetaR-II expression were observed following surgery between the groups with and without prior radiation in the transition area between the graft and the graft bed, the group undergoing prior radiation and subsequent grafting showed significantly increased expression in the bed compared to the non-preirradiated group with a maximum on postoperative day 7 (week 1, p = 0.003; week 2-4, p < 0.001). In irradiated tissues the up-regulation of TGFbetaR-II expression correlated with an increase of activated TGFbeta1 and latency-associated peptide expression compared to non-irradiated tissues. After irradiation, a significantly increased TGFbetaR-II expression was identified in the irradiated graft bed, which may be the reason for delayed reepithelialization and fibrosis. Exogenous blocking or TGFbetaR-II inhibitors could therefore represent a new therapeutic approach for improving wound healing after preoperative radiotherapy.

Overexpression of transforming growth factor-beta3 immunohistochemical staining in extramammary Paget's disease, but downregulated expression in Bowen's disease

BACKGROUND

The role of transforming growth factor-beta (TGF-beta) in carcinogenesis is complex, with some reports indicating a tumor inhibition role and others indicating a tumor promotion role. In particular, TGF-beta3 is thought to play a key role in controlling epithelial homeostasis. Immunopositive p53 has been demonstrated in a variety of human malignant tumors and its role in oncogenesis and tumor progression is thought to be important. Extramammary Paget's disease (EPD) and Bowen's disease are skin cancers of unknown histogenesis.

OBJECTIVE

To clarify the role of TGF-beta3 and p53 in EPD and Bowen's disease and to better understand the origin of these disorders.

METHODS

Specimens were obtained from 12 patients with EPD and 12 patients with Bowen's disease seen at our clinic between 1993 and 2000. TGF-beta3 and p53 immunohistochemical staining was performed.

RESULTS

In three of the 12 EPD patients and five of the 12 Bowen's disease patients, positive p53 staining was detected. In contrast, TGF-beta3 overexpression was detected in all EPD patients, whereas downregulated TGF-beta3 expression was detected in all Bowen's disease patients.

CONCLUSIONS

The present data suggest different roles for TGF-beta3 in abnormal epidermal cells in EPD and Bowen's disease. Thus, TGF-beta3 expression may be modulated differently via a p53-dependent or -independent pathway in the pathogenesis of EPD and Bowen's disease. Moreover, high TGF-beta expression appears to be a useful indicator of tumor activity in EPD.