transforming-growth-factor-beta and Alopecia

This article discusses the mechanisms via topically applied products containing herbs and their active constituents affect the hair growth process. It was reported that the mechanisms involving (1) insulin-like growth factor-I (IGF-I), (2) vascular endothelial growth factor (VEGF), (3) epidermal growth factor (EGF), (4) fibroblast growth factor 2 (FGF-2), (5) endothelial nitric oxide synthase (eNOS), (6) Wnt/β-catenin signalling pathway, (7) prostaglandin E (PGE), (8) prostaglandin F (PGF) stimulate hair growth, whereas the mechanisms engaging (1) 5α-reductase and dihydrotestosterone (DHT), (2) transforming growth factor beta (TGF-β), (3) fibroblast growth factor 5 (FGF-5), (4) prostaglandin D

Topics: Administration, Topical; Alopecia; Animals; Epidermal Growth Factor; Fibroblast Growth Factors; Humans; Insulin-Like Growth Factor I; Mice; Nitric Oxide Synthase Type III; Plant Preparations; Prostaglandins; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Wnt Signaling Pathway

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a single-gene disorder directly affecting the cerebral small blood vessels, that is caused by mutations in the HTRA1 gene encoding HtrA serine peptidase/protease 1 (HTRA1). CARASIL is the second known genetic form of ischemic, nonhypertensive, cerebral small-vessel diseases with an identified gene, following CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). The exact prevalence of CARASIL is currently unknown, and so far about 50 patients have been reported, most of them from Japan and two from China. Genetically no founder haplotype has been identified, and so the disease is expected to be found more widely. The main clinical manifestations are ischemic stroke or stepwise deterioration in brain functions, progressive dementia, premature baldness, and attacks of severe low back pain or spondylosis deformans/disk herniation. The most characteristic brain MRI findings are homogeneously confluent white-matter changes and multiple lacunar infarctions in the basal ganglia and thalamus. Histopathologically, CARASIL is characterized by intense arteriosclerosis, mainly in the small penetrating arteries, without granular osmiophilic materials (GOM) or amyloid deposition. CARASIL is a prototype single-gene disorder of cerebral small vessels, secondary to and distinct from CADASIL. CARASIL-associated mutant HTRA1s exhibited decreased protease activity and failed to repress transforming growth factor-β (TGF-β) family signaling, indicating that the increased TGF-β signaling causes arteriopathy in CARASIL. Therefore, HTRA1 represents another new gene to be considered in future studies of the mechanisms and therapeutic strategies of cerebral small-vessel diseases, as well as alopecia and degenerative vertebral/disk diseases.

Topics: Adult; Alopecia; Blood Vessels; Brain; Cerebral Infarction; Dementia, Vascular; Genes, Recessive; High-Temperature Requirement A Serine Peptidase 1; Humans; Leukoencephalopathy, Progressive Multifocal; Low Back Pain; Male; Middle Aged; Mutation; Serine Endopeptidases; Spondylosis; Syndrome; Transforming Growth Factor beta

Male pattern baldness is the result of premature entry into catagen due to androgens. In order to prevent hair loss, it is important to understand two critical steps, i.e., the induction mechanism of premature entry and the regression process of catagen. At the initiation, dihydrotestosterone (DHT) stimulates synthesis of transforming growth factor-beta2 (TGF-beta2) in dermal papilla cells. TGF-beta2 suppresses proliferation of epithelial cells and stimulates synthesis of certain caspases. Then TGF-beta2 triggers the intrinsic caspase network and subsequently epithelial cells are eliminated through apoptotic cell death. TGF-beta antagonists are effective in preventing catagen-like morphological changes and in promoting elongation of hair follicles in vivo and in vitro. These lines of evidence strongly suggest the presence of a "catagen cascade" in male pattern baldness, involving: (1) the conversion of testosterone to DHT by type II 5-alpha-reductase; (2) the synthesis of TGF-beta2 in dermal papilla cells; and (3) the activation of the intrinsic caspase network. These sequential events contribute to the shortening of the human hair cycle.

Topics: Alopecia; Caspases; Dihydrotestosterone; Hair Follicle; Humans; In Vitro Techniques; Male; Testosterone; Transforming Growth Factor beta; Transforming Growth Factor beta2

Hypoxia-inducible factors (HIFs) induce numerous genes regulating oxygen homeostasis. As oxygen sensors of the cells, the HIF prolyl 4-hydroxylases (HIF-P4Hs) regulate the stability of HIFs in an oxygen-dependent manner. During hair follicle (HF) morphogenesis and cycling, the location of dermal papilla (DP) alternates between the dermis and hypodermis and results in varying oxygen levels for the DP cells. These cells are known to express hypoxia-inducible genes, but the role of the hypoxia response pathway in HF development and homeostasis has not been studied. Using conditional gene targeting and analysis of hair morphogenesis, we show here that lack of Hif-p4h-2 in Forkhead box D1 (FoxD1)-lineage mesodermal cells interferes with the normal HF development in mice. FoxD1-lineage cells were found to be mainly mesenchymal cells located in the dermis of truncal skin, including those cells composing the DP of HFs. We found that upon Hif-p4h-2 inactivation, HF development was disturbed during the first catagen leading to formation of epithelial-lined HF cysts filled by unorganized keratins, which eventually manifested as truncal alopecia. Furthermore, the depletion of Hif-p4h-2 led to HIF stabilization and dysregulation of multiple genes involved in keratin formation, HF differentiation, and HIF, transforming growth factor β (TGF-β), and Notch signaling. We hypothesize that the failure of HF cycling is likely to be mechanistically caused by disruption of the interplay of the HIF, TGF-β, and Notch pathways. In summary, we show here for the first time that HIF-P4H-2 function in FoxD1-lineage cells is essential for the normal development and homeostasis of HFs.

Topics: Alopecia; Animals; Hypoxia-Inducible Factor-Proline Dioxygenases; Mice; Oxygen; Transforming Growth Factor beta

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a life-threatening, inherited, nonhypertensive arteriole disease of the brain. Therapeutic strategy for CARASIL is limited because its pathogenesis is not clear. We previously reported the first family with CARASIL in China, which involves a high-temperature requirement serine protease gene mutation (HtrA1. Food maze and water maze experiments were used in the behavioral studies. Pathological studies were carried out by arteriole labeling staining and electron microscopy. The mRNA and protein expression levels of the key factors of TGF-β/Smad signaling pathway (TGF-β, Smad2, Smad3, and Smad4) in the brain of the model mice were detected by immunohistochemistry, real-time quantitative polymerase chain reaction (RT-PCR), and Western blot assay.. The food maze and water maze experiment data showed significant differences between the Mut and wild-type (WT) mice in the first time to find food, the time to contact the escape table for the first time, and the number of times to travel in the escape table quadrant (p < 0.001). The results of vascular labeling staining showed that some small arteries in the brain of Mut mice lost normal structure. The results of electron microscopy showed that the cell morphologies in the cortex and hippocampus of Mut mice were abnormal; the number of synapses was reduced; the walls of capillaries, venules, and arterioles thickened; lumen stenosis and other abnormal phenomenon occurred; and lipofuscin deposition and autophagosomes were found in the hippocampus. Immunohistochemistry, RT-PCR, and Western Blot results showed that the mRNA and protein expression levels of TGF-β, Smad2, and Smad3 in the brain of Mut mice increased to different degrees.. The most significant innovation of this study is the first study on the pathogenesis of CARASIL disease using model animals. The Mut mice can well simulate the pathogenesis of CARASIL in behavioral and pathological aspects. The TGF-β/Smad signaling pathway, which is involved in the pathogenesis of CARASIL, is abnormally upregulated in the brain of Mut mice.

Topics: Alopecia; Animals; Cerebral Arterial Diseases; Cerebral Infarction; Cerebrovascular Disorders; Cognitive Dysfunction; High-Temperature Requirement A Serine Peptidase 1; Leukoencephalopathies; Mice; RNA, Messenger; Signal Transduction; Spinal Diseases; Transforming Growth Factor beta

Cerebral small vessel disease (CSVD) causes dementia and gait disturbance due to arteriopathy. Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a hereditary form of CSVD caused by loss of high-temperature requirement A1 (HTRA1) serine protease activity. In CARASIL, arteriopathy causes intimal thickening, smooth muscle cell (SMC) degeneration, elastic lamina splitting, and vasodilation. The molecular mechanisms were proposed to involve the accumulation of matrisome proteins as substrates or abnormalities in transforming growth factor β (TGF-β) signaling. Here, we show that HTRA1-/- mice exhibited features of CARASIL-associated arteriopathy: intimal thickening, abnormal elastic lamina, and vasodilation. In addition, the mice exhibited reduced distensibility of the cerebral arteries and blood flow in the cerebral cortex. In the thickened intima, matrisome proteins, including the hub protein fibronectin (FN) and latent TGF-β binding protein 4 (LTBP-4), which are substrates of HTRA1, accumulated. Candesartan treatment alleviated matrisome protein accumulation and normalized the vascular distensibility and cerebral blood flow. Furthermore, candesartan reduced the mRNA expression of Fn1, Ltbp-4, and Adamtsl2, which are involved in forming the extracellular matrix network. Our results indicate that these accumulated matrisome proteins may be potential therapeutic targets for arteriopathy in CARASIL.

Topics: ADAMTS Proteins; Alopecia; Animals; Benzimidazoles; Biphenyl Compounds; Cerebral Infarction; Cerebrovascular Circulation; Disease Progression; Extracellular Matrix Proteins; High-Temperature Requirement A Serine Peptidase 1; Latent TGF-beta Binding Proteins; Leukoencephalopathies; Mice; Mice, Inbred C57BL; Recombinant Proteins; Spinal Diseases; Tetrazoles; Transforming Growth Factor beta

The exact pathogenic mechanism causes hair miniaturization during androgenic alopecia (AGA) has not been delineated. Recent evidence has shown a role for non-coding regulatory RNAs, such as microRNAs (miRNAs), in skin and hair disease. There is no reported information about the role of miRNAs in hair epithelial cells of AGA.. To investigate the roles of miRNAs affecting AGA in normal and patient's epithelial hair cells.. Normal follicular stem and progenitor cells, as well as follicular patient's stem cells, were sorted from hair follicles, and a miRNA q-PCR profiling to compare the expression of 748 miRNA (miRs) in sorted cells were performed. Further, we examined the putative functional implication of the most differentially regulated miRNA (miR-324-3p) in differentiation, proliferation and migration of cultured keratinocytes by qRT-PCR, immunofluorescence, and scratch assay. To explore the mechanisms underlying the effects of miR-324-3p, we used specific chemical inhibitors targeting pathways influenced by miR-324-3p.. We provide a comprehensive assessment of the "miRNome" of normal and AGA follicular stem and progenitor cells. Differentially regulated miRNA signatures highlight several miRNA candidates including miRNA-324-3p as mis regulated in patient's stem cells. We find that miR-324-3p promotes differentiation and migration of cultured keratinocytes likely through the regulation of mitogen-activated protein kinase (MAPK) and transforming growth factor (TGF)-β signaling. Importantly, pharmacological inhibition of the TGF-β signaling pathway using Alk5i promotes hair shaft elongation in an organ-culture system.. Together, we offer a platform for understanding miRNA dynamic regulation in follicular stem and progenitor cells in baldness and highlight miR-324-3p as a promising target for its treatment.

Topics: Adult; Alopecia; Cell Differentiation; Cell Line; Cell Movement; Cell Proliferation; Gene Expression Profiling; Hair Follicle; Humans; Keratinocytes; Male; MAP Kinase Signaling System; MicroRNAs; Middle Aged; Protein Kinase Inhibitors; Receptor, Transforming Growth Factor-beta Type I; Stem Cells; Transforming Growth Factor beta

High temperature requirement A1 (HTRA1) is a serine protease playing a modulatory role in various cell processes, particularly in the regulation of transforming growth factor-β (TGF-β) signaling. A deleterious role in late-onset cerebral small vessel diseases (CSVDs) of heterozygous HTRA1 mutations, otherwise causative in homozygosity of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy, was recently suggested. However, the pathomechanism of these heterozygous mutations is still undefined. Our aim is to evaluate the expression profile and activity of HTRA1 on TGF-β signaling in fibroblasts from four subjects carrying the HTRA1 heterozygous mutations-p.E42Dfs*173, p.A321T, p.G295R, and p.Q151K. We found a 50% reduction of HTRA1 expression in HTRA1 mutation carriers compared to the control. Moreover, we showed no changes in TGF-β signaling pathway downstream intermediate, Phospho Smad2/3. However, we found overexpression of genes involved in the extracellular matrix formation in two heterozygous HTRA1 carriers. Our results suggest that each heterozygous HTRA1 missense mutation displays a different and peculiar HTRA1 expression pattern and that CSVD phenotype may also result from 50% of HTRA1 expression.

Topics: Alopecia; Cells, Cultured; Cerebral Infarction; Cerebrovascular Disorders; Female; Fibroblasts; Heterozygote; High-Temperature Requirement A Serine Peptidase 1; Humans; Leukoencephalopathies; Male; Middle Aged; Mutation; Signal Transduction; Spinal Diseases; Transcriptome; Transforming Growth Factor beta

Androgenetic alopecia (AGA) is a progressive dermatological disorder of frontal and vertex scalp hair loss leading to baldness in men. This study aimed to identify candidate genes involved in AGA through an in silico search strategy. The gene expression profile GS36169, which contains microarray gene expression data from bald frontal and haired occipital scalps of five men with AGA, was downloaded from the Gene Expression Omnibus (GEO) database. The differential gene expression analysis for all five subjects was carried out separately by PUMA package in R and identified 32 differentially expressed genes (DEGs) common to all five subjects. Gene ontology (GO) biological process and pathway- enrichment analyses of the DEGs were conducted separately for the up-regulated and down-regulated genes. ReactomeFIViz app was utilized to construct the protein functional interaction network for the DEGs. Through GO biological process and pathway analysis on the clusters of the Reactome FI network, we found that the down-regulated DEGs participate in Wnt signaling, TGF-beta signaling, and up-regulated DEGs participate in oxidative-stress- related pathways.

Topics: Adult; Aged; Alopecia; Biopsy; Computational Biology; Datasets as Topic; Down-Regulation; Gene Expression Profiling; Hair Follicle; Humans; Male; Middle Aged; Oligonucleotide Array Sequence Analysis; Oxidative Stress; Protein Interaction Maps; Scalp; Transforming Growth Factor beta; Up-Regulation; Wnt Signaling Pathway

Plenty of plant extracts have been used for treating hair loss. This study aims to investigate the effects of liposterolic extracts of Serenoa repens (LSESr) on hair cell growth and regeneration of hair, and clarify the associated mechanisms.. Human keratinocyte cells (HACAT) were cultured, incubated with dihydrotestosterone (DHT) and treated with LSESr. Cell viability was examined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H- tetrazolium bromide (MTT) assay. Hair loss C57BL/6 mouse model was established by inducing with DHT. Hair growth, density, and thickness were evaluated. Back skin samples were collected and stained with hematoxylin and eosin (HE) assay. B-cell lymphoma-2 (Bcl-2), Bcl-2 associated protein X (Bax), cleaved caspase 3 and transforming growth factor β2 (TGF-β2) were examined using Western blot assay.. LSESr treatment significantly increased HACAT cell viabilities compared to DHT-only treated cells (p<0.05). LSESr treatment post injection of DHT significantly converted skin color from pink to gray and increased hair density, weight and thickness compared to DHT-only treated mice (p<0.05). LSESr treatment significantly triggered follicle growth and decreased inflammatory response. LSESr treatment significantly decreased TGF-β2 and cleaved caspase 3 expression of hair loss mouse models compared to that of DHT treated mice (p<0.05). LSESr treatment significantly enhanced Bcl-2 expression and reduced Bax expression compared to that of DHT treated mice (p<0.05). Meanwhile, effects of LSESr were substantial even achieving to the potential of finasteride.. LSESr promoted the hair regeneration and repair of hair loss mouse models by activating TGF-β signaling and mitochondrial signaling pathway.

Topics: Alopecia; Animals; Cells, Cultured; Disease Models, Animal; Hair; Humans; Keratinocytes; Mice; Mice, Inbred C57BL; Mitochondria; Plant Extracts; Regeneration; Serenoa; Signal Transduction; Transforming Growth Factor beta

Androgenic alopecia (AGA) occurs as a result of the contraction of the anagen phase because of the action of androgens on hair follicles. TGF-β production from dermal papillae is enhanced by androgens, and growth inhibition of hair-follicle cells is induced by TGF-β, and the hair cycle progresses from the anagen phase to the catagen phase. We investigated both the in vitro and in vivo potency of the newly identified ALK5 inhibitor TP0427736 {6-[4-(4-methyl-1,3-thiazol-2-yl)-1H-imidazol-5-yl]-1,3-benzothiazole}.. For in vitro study, kinase inhibitory activity was evaluated with ELISA, and inhibitory activity against TGF-β-induced Smad2/3 phosphorylation in A549 cells and TGF-β-induced growth inhibition of human outer root sheath cells were assayed using ELISA. For in vivo study, we used a mouse model that had been synchronized through dorsal hair depilation.. TP0427736, a potent ALK5 inhibitor with appropriate in vitro and in vivo profiles, may serve as a potential new therapy for AGA.　.

Topics: Administration, Topical; Alopecia; Animals; Benzothiazoles; Bone Morphogenetic Protein Receptors, Type I; Enzyme-Linked Immunosorbent Assay; Hair Follicle; Humans; Imidazoles; Inhibitory Concentration 50; Mice; Phosphorylation; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta

Male androgenetic alopecia (AGA) is the most common form of hair loss in men. It is characterized by a distinct pattern of progressive hair loss starting from the frontal area and the vertex of the scalp. Although several genetic risk loci have been identified, relevant genes for AGA remain to be defined.. To identify biomarkers associated with AGA.. Molecular biomarkers associated with premature AGA were identified through gene expression analysis using cDNA generated from scalp vertex biopsies of hairless or bald men with premature AGA, and healthy volunteers.. This monocentric study reveals that genes encoding mast cell granule enzymes, inflammatory mediators and immunoglobulin-associated immune mediators were significantly overexpressed in AGA. In contrast, underexpressed genes appear to be associated with the Wnt/β-catenin and bone morphogenic protein/transforming growth factor-β signalling pathways. Although involvement of these pathways in hair follicle regeneration is well described, functional interpretation of the transcriptomic data highlights different events that account for their inhibition. In particular, one of these events depends on the dysregulated expression of proopiomelanocortin, as confirmed by polymerase chain reaction and immunohistochemistry. In addition, lower expression of CYP27B1 in patients with AGA supports the notion that changes in vitamin D metabolism contributes to hair loss.. This study provides compelling evidence for distinct molecular events contributing to alopecia that may pave the way for new therapeutic approaches.

Topics: 25-Hydroxyvitamin D3 1-alpha-Hydroxylase; Adult; Alopecia; Analysis of Variance; Bone Morphogenetic Proteins; Case-Control Studies; Catenins; DNA, Complementary; Down-Regulation; Gene Expression; Gene Expression Profiling; Genetic Markers; Hair Follicle; Humans; Male; Signal Transduction; Transforming Growth Factor beta; Up-Regulation; Vitamin D; Wnt Signaling Pathway

Hair loss (alopecia) is a universal problem for numerous people in the world. The present study was conducted to investigate the effects of red ginseng oil (RGO) and its major components on hair re-growth using testosterone (TES)-induced delay of anagen entry in C57BL/6 mice and their mechanisms of action. Seven-week-old C57BL/6 mice were daily treated with TES for 1 h prior to topical application of 10% RGO, 1% linoleic acid (LA), 1% β-sitosterol (SITOS), or 1% bicyclo(10.1.0)tridec-1-ene (BICYCLO) once a day for 28 days. Hair regenerative capacity was significantly restored by treatment of RGO and its major compounds in the TES-treated mice. Histological analysis showed that RGO along with LA and SITOS but not BICYCLO promoted hair growth through early inducing anagen phase that was delayed by TES in mice. Treatment of mice with RGO, LA, or SITOS up-regulated Wnt/β-catenin and Shh/Gli pathways-mediated expression of genes such as β-catenin, Lef-1, Sonic hedgehog, Smoothened, Gli-1, Cyclin D1, and Cyclin E in the TES-treated mice. In addition, RGO and its major components reduced the protein level of TGF-β but enhanced the expression of anti-apoptotic protein Bcl-2. These results suggest that RGO is a potent novel therapeutic natural product for treatment of androgenic alopecia possibly through hair re-growth activity of its major components such as LA and SITOS.

Topics: Alopecia; Animals; beta Catenin; Cyclins; Disease Models, Animal; Gene Expression Regulation; Hair Follicle; Hedgehog Proteins; Linoleic Acid; Lymphoid Enhancer-Binding Factor 1; Male; Mice; Mice, Inbred C57BL; Panax; Plant Oils; Proto-Oncogene Proteins c-bcl-2; Regeneration; Sitosterols; Smoothened Receptor; Testosterone; Transforming Growth Factor beta; Zinc Finger Protein GLI1

Wnt and transforming growth factor-β (TGF-β) signaling pathways are known to be involved in the pathogenesis of androgenetic alopecia (AGA). However, the way that Wnt and TGF-β signaling is altered in patients with AGA and whether there exists a crosstalk between them in pathogenetic process of AGA remain unclear.. To investigate the expression of Wnt and TGF-β signaling and the crosstalk between these 2 signaling pathways in AGA.. Fifteen male patients with AGA were recruited for our research. Fifteen scalp specimens of the balding were collected from frontal areas, and 9 nonbalding were collected from occipital areas. We analyzed the expression and activation of downstream Wnt and TGF-β signaling molecules in both balding and nonbalding hair follicles isolated from scalp specimens. Furthermore, we evaluated the activation of Wnt and TGF-β signaling after either of them was blocked with the inhibitor in balding and nonbalding dermal papilla (DP) cells.. Compared with the nonbalding counterparts, the mRNA level of Wnt10a and LEF1 was decreased. But TβRI and TβRII, and the protein expression of TGF-β1 was elevated in balding hair follicles. To investigate the crosstalk between Wnt and TGF-β signaling, we used SB431542 to inhibit the TGF-β signaling in balding DP cells and found that SB431542 significantly attenuated the phosphorylation of Smad2 and Akt. However, the mRNA level of Wnt10a, LEF1, and the nuclear translocation of β-catenin was increased. On the other hand, we suppressed the Wnt signaling by XAV939 in nonbalding DP cells, which displayed that the level of β-catenin and LEF1 was significantly inhibited; however, the level of active TGF-β1 and the phosphorylation of Smad2 and Akt were up-regulated.. These data indicate that crosstalk between Wnt/β-catenin and TGF-β signaling pathways may exist as one of the important mechanisms contributing to AGA.

Topics: Adult; Alopecia; Blotting, Western; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Humans; Lymphoid Enhancer-Binding Factor 1; Male; Middle Aged; Real-Time Polymerase Chain Reaction; Retrospective Studies; RNA, Messenger; Signal Transduction; Transforming Growth Factor beta; Wnt Signaling Pathway

Mycophenolic acid (MPA), the active metabolite of mycophenolate mofetil, has anti-inflammatory effects, and is widely used as an immunomodulatory agent. However, the beneficial effect of MPA in hair-loss disorders is not fully understood.. To investigate the direct effect of MPA on dermal papilla cells (DPCs), and to examine the hair growth-stimulating effects of MPA topically applied to mouse skin.. Cultured DPCs were treated with various concentrations of MPA and analysed by MTT assay. Expressions of hair growth-related genes, including Wnt/β-catenin pathway-related genes and cellular apoptosis-regulating genes, such as Bcl-2, Bax and caspase-9, were examined using reverse transcription (RT)-PCR and western blotting. The Wnt/extracellular signal-regulated kinase (ERK) pathway was analysed by western blotting. The effect of topically applied MPA on anagen hair follicle induction after microneedle (MN) treatment with or without minoxidil (MXD) was evaluated by histopathological examination and RT-PCR.. MPA showed a promoting effect on DPC proliferation, which was associated with increased Axin2 transcription levels. In addition, phospho-ERK protein was detected in the MPA-treated DPCs. An increased Bcl-2/Bax transcript ratio contributed to cellular proliferation, and this was maintained in the MPA-treated environment. Topically applied MPA promoted anagen hair follicle induction in mice. The effect of MPA on hair follicles was compatible with that of MXD, and this effect was accelerated by MN treatment.. MPA promotes proliferation of DPCs and induction of anagen hair follicles in mice. This finding raises the possibility that MPA could be used as a treatment option for hair-loss disorders.

Topics: Alopecia; Animals; Apoptosis; Blotting, Western; Cell Proliferation; Cells, Cultured; Dermis; Disease Models, Animal; Female; Gene Expression Regulation; Growth Substances; Hair Follicle; Immunosuppressive Agents; Mice; Mice, Inbred C3H; Mitogen-Activated Protein Kinases; Mycophenolic Acid; Proto-Oncogene Proteins; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Transforming Growth Factor beta; Wnt Signaling Pathway

The potential hair growth-promoting activity of rice bran supercritical CO2 extract (RB-SCE) and major components of RB-SCE, linoleic acid, policosanol, γ-oryzanol, and γ-tocotrienol, were evaluated with the histological morphology and mRNA expression levels of cell growth factors using real-time reverse transcriptase-polymerase chain reaction (PCR) in C57BL/6 mice. RB-SCE showed hair growth-promoting potential to a similar extent as 3% minoxidil, showing that the hair follicles were induced to be in the anagen stage. The numbers of the hair follicles were significantly increased. In addition, mRNA expression levels of vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), and keratinocyte growth factor (KGF) were also significantly increased and that of transforming growth factor-β (TGF-β) decreased in RB-SCE-treated groups. Among the major components of RB-SCE, linoleic acid and γ-oryzanol induced the formation of hair follicles according to examination of histological morphology and mRNA expression levels of cell growth factors. In conclusion, our results demonstrate that RB-SCE, particularly linoleic acid and γ-oryzanol, promotes hair growth and suggests RB-SCE can be applied as hair loss treatment.

Topics: Alopecia; Animals; Fibroblast Growth Factor 7; Hair; Hair Follicle; Linoleic Acid; Mice; Mice, Inbred C57BL; Oryza; Phenylpropionates; Phytotherapy; Plant Extracts; RNA, Messenger; Seeds; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

This study was conducted to test whether ginsenoside F2 can reduce hair loss by influencing sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) and the transforming growth factor beta (TGF-β) pathway of apoptosis in dihydrotestosterone (DHT)-treated hair cells and in a DHT-induced hair loss model in mice. Results for ginsenoside F2 were compared with finasteride. DHT inhibits proliferation of hair cells and induces androgenetic alopecia and was shown to activate an apoptosis signal pathway both in vitro and in vivo. The cell-based 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the proliferation rates of DHT-treated human hair dermal papilla cells (HHDPCs) and HaCaTs increased by 48% in the ginsenoside F2-treated group and by 12% in the finasteride-treated group. Western blot analysis showed that ginsenoside F2 decreased expression of TGF-β2 related factors involved in hair loss. The present study suggested a hair loss related pathway by changing SCAP related apoptosis pathway, which has been known to control cholesterol metabolism. SCAP, sterol regulatory element-binding protein (SREBP) and caspase-12 expression in the ginsenoside F2-treated group were decreased compared to the DHT and finasteride-treated group. C57BL/6 mice were also prepared by injection with DHT and then treated with ginsenoside F2 or finasteride. Hair growth rate, density, thickness measurements and tissue histotological analysis in these groups suggested that ginsenoside F2 suppressed hair cell apoptosis and premature entry to catagen more effectively than finasteride. Our results indicated that ginsenoside F2 decreased the expression of TGF-β2 and SCAP proteins, which have been suggested to be involved in apoptosis and entry into catagen. This study provides evidence those factors in the SCAP pathway could be targets for hair loss prevention drugs.

Topics: Alopecia; Animals; Apoptosis; Caspase 12; Cell Proliferation; Dihydrotestosterone; Disease Models, Animal; Finasteride; Ginsenosides; Hair Follicle; Humans; Intracellular Signaling Peptides and Proteins; Membrane Proteins; Mice; Signal Transduction; Sterol Regulatory Element Binding Proteins; Transforming Growth Factor beta

7-Methoxy-6-[4-(4-methyl-1,3-thiazol-2-yl)-1H-imidazol-5-yl]-1,3-benzothiazole 11 (TASP0382088) was synthesized and evaluated as transforming growth factor-β (TGF-β) type I receptor (also known as activin receptor-like kinase 5 or ALK5) inhibitor. Compound 11, a potent and selective ALK5 inhibitor, exhibited good enzyme inhibitory activity (IC50=4.8 nM) as well as inhibitory activity against TGF-β-induced Smad2/3 phosphorylation at a cellular level (IC50=17 nM). The introduction of a methoxy group to the benzothiazole ring in 1 and the break up of the planarity between the imidazole ring and the thiazole ring improved the solubility in the lotion base of 11. Furthermore, the topical application of 3% 11 lotion significantly inhibited Smad2 phosphorylation in mouse skin at 8 h after application (71% inhibition, compared with vehicle-treated animals).

Topics: Alopecia; Animals; Benzothiazoles; Enzyme Inhibitors; Female; Imidazoles; Mice; Mice, Inbred C57BL; Phosphorylation; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta

Radiation therapy (RT) to the head and neck often results in damage to the vocal folds (VF) and surrounding structures. Characterization and treatment of these sequelae is limited, likely due to the lack of experimental models.. Larynges from rats exposed to 2 fractionation schedules (40 Gy total) were analyzed histologically. In vitro, reactive oxygen species (ROS) synthesis, and transcription of select genes associated with ROS, inflammation, and fibrosis were examined in VF fibroblasts after single-dose radiation.. Although radiation-induced histologic alterations are made to VF architecture, 1 fractionation schedule was accompanied by significant morbidity and mortality. In vitro, radiation increased ROS synthesis and inflammatory and profibrotic gene expression.. Our data suggest that hyperfractionated RT is more tolerable. Utilizing this model, RT-induced histologic aberrations are made to the VF mucosa. In addition, a relationship between radiation, ROS, and inflammatory and fibrotic gene expression was observed in vitro.

Topics: Alopecia; Animals; Dehydration; Dose Fractionation, Radiation; Erythema; Fibrosis; Heme Oxygenase-1; Hypertrophy; In Vitro Techniques; Laryngeal Mucosa; Male; Matrix Metalloproteinase 1; Models, Animal; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; RNA, Messenger; Skin Ulcer; Transforming Growth Factor beta; Vocal Cords; Weight Loss

N-WASP is a cytoplasmic molecule mediating Arp2/3 nucleated actin polymerization. Mice with a keratinocyte-specific deletion of the gene encoding N-WASP showed normal interfollicular epidermis, but delayed hair-follicle morphogenesis and abnormal hair-follicle cycling, associated with cyclic alopecia and prolonged catagen and telogen phases. The delayed anagen onset correlated with an increased expression of the cell-cycle inhibitor p21CIP, and increased activity of the TGFbeta pathway, a known inducer of p21CIP expression. Primary N-WASP-null keratinocytes showed reduced growth compared with control cells and enhanced expression of the gene encoding the cell-cycle inhibitor p15INK4B, a TGFbeta target gene. Inhibition of TGFbeta signaling blocked overexpression of p15INK4B and restored proliferation of N-WASP-deficient keratinocytes in vitro. However, induction of N-WASP gene deletion in vitro did not result in obvious changes in TGFbeta signaling or growth of keratinocytes, indicating that the in vivo environment is required for the phenotype development. These data identify the actin nucleation regulator N-WASP as a novel element of hair-cycle control that modulates the antiproliferative and pro-apoptotic TGFbeta pathway in keratinocytes in vivo and in vitro.

Topics: Actin Cytoskeleton; Alopecia; Animals; Cell Cycle; Cell Proliferation; Cells, Cultured; Cyclin-Dependent Kinase Inhibitor p15; Cyclin-Dependent Kinase Inhibitor p21; Hair Follicle; Keratinocytes; Mice; Morphogenesis; Signal Transduction; Transforming Growth Factor beta; Wiskott-Aldrich Syndrome Protein, Neuronal

The genetic cause of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), which is characterized by ischemic, nonhypertensive, cerebral small-vessel disease with associated alopecia and spondylosis, is unclear.. In five families with CARASIL, we carried out linkage analysis, fine mapping of the region implicated in the disease, and sequence analysis of a candidate gene. We also conducted functional analysis of wild-type and mutant gene products and measured the signaling by members of the transforming growth factor beta (TGF-beta) family and gene and protein expression in the small arteries in the cerebrum of two patients with CARASIL.. We found linkage of the disease to the 2.4-Mb region on chromosome 10q, which contains the HtrA serine protease 1 (HTRA1) gene. HTRA1 is a serine protease that represses signaling by TGF-beta family members. Sequence analysis revealed two nonsense mutations and two missense mutations in HTRA1. The missense mutations and one of the nonsense mutations resulted in protein products that had comparatively low levels of protease activity and did not repress signaling by the TGF-beta family. The other nonsense mutation resulted in the loss of HTRA1 protein by nonsense-mediated decay of messenger RNA. Immunohistochemical analysis of the cerebral small arteries in affected persons showed increased expression of the extra domain-A region of fibronectin and versican in the thickened tunica intima and of TGF-beta1 in the tunica media.. CARASIL is associated with mutations in the HTRA1 gene. Our findings indicate a link between repressed inhibition of signaling by the TGF-beta family and ischemic cerebral small-vessel disease, alopecia, and spondylosis.

Topics: Adult; Aged, 80 and over; Alopecia; Cerebral Arterial Diseases; Cerebral Arteries; Cerebral Infarction; Female; Genes, Recessive; High-Temperature Requirement A Serine Peptidase 1; Humans; Male; Middle Aged; Mutation; Pedigree; Serine Endopeptidases; Signal Transduction; Spondylosis; Syndrome; Transcription, Genetic; Transforming Growth Factor beta; Tunica Intima

Folliculitis decalvans (FD) is a rare variant of primary cicatricial alopecia, for which the etiopathogenesis remains unclear. Our purpose was to evaluate whether certain immunologic mechanisms might have a significant role in the pathogenesis of FD. Lesional scalp biopsy specimens from 7 patients with FD, 7 with lichen planopilaris, and 4 with alopecia areata were studied immunohistochemically by using monoclonal antibodies to CD1a, CD3, CD4, CD8, CD20, CD25, HLA-DR, interleukin (IL)-1beta, IL-4, IL-8, interferon gamma, tumor necrosis factor alpha, basic fibroblast growth factor (b-FGF), transforming growth factor (TGF)-beta, endothelial leukocyte adhesion molecule 1, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule. We showed that early FD lesions are characterized by an infiltration of activated T-helper cells, featuring mixed TH1/TH2 polarization. IL-8 and ICAM-1 may contribute to the infiltration of neutrophils, whereas b-FGF and TGF-beta may represent important mediators of the fibrosis that characterizes late-phase FD.

Topics: Adult; Aged; Alopecia; Alopecia Areata; Female; Fibroblast Growth Factor 2; Humans; Immunohistochemistry; Intercellular Adhesion Molecule-1; Interleukin-8; Lichen Planus; Male; Middle Aged; T-Lymphocytes; Transforming Growth Factor beta

Smad4 is the common mediator for TGFbeta signals, which play important functions in many biological processes. To study the role of Smad4 in skin development and epidermal tumorigenesis, we disrupted this gene in skin using the Cre-loxP approach. We showed that absence of Smad4 blocked hair follicle differentiation and cycling, leading to a progressive hair loss of mutant (MT) mice. MT hair follicles exhibited diminished expression of Lef1, and increased proliferative cells in the outer root sheath. Additionally, the skin of MT mice exhibited increased proliferation of basal keratinocytes and epidermal hyperplasia. Furthermore, we provide evidence that the absence of Smad4 resulted in a block of both TGFbeta and bone morphogenetic protein (BMP) signaling pathways, including p21, a well-known cyclin-dependent kinase inhibitor. Consequently, all MT mice developed spontaneous malignant skin tumors from 3 months to 13 months of age. The majority of tumors are malignant squamous cell carcinomas. A most notable finding is that tumorigenesis is accompanied by inactivation of phosphatase and tensin homolog deleted on chromosome 10 (Pten), activation of AKT, fast proliferation and nuclear accumulation of cyclin D1. These observations revealed the essential functions of Smad4-mediated signals in repressing skin tumor formation through the TGFbeta/BMP pathway, which interacts with the Pten signaling pathway.

Topics: Alopecia; Animals; Bone Morphogenetic Proteins; Carcinoma, Squamous Cell; Cell Differentiation; Cell Nucleus; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Enzyme Activation; Epidermis; Female; Hair Follicle; Hyperplasia; In Situ Hybridization; Integrases; Keratinocytes; Male; Mice; Mice, Knockout; Mice, Transgenic; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Skin; Skin Neoplasms; Smad4 Protein; Transforming Growth Factor beta

Topics: Adult; Alopecia; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Humans; Incidental Findings; Male; Recombinant Proteins; Tibial Fractures; Transforming Growth Factor beta

Smad4 is the common mediator of transforming growth factor-beta (TGF-beta) superfamily signaling, which functions in diverse developmental processes in mammals. To study the role of Smad4 in skin development, a keratinocyte-specific null mutant of Smad4 (Smad4(co/co);K5-Cre) was generated in mice using the Cre-loxP system. The Smad4-mutant mice exhibited progressive alopecia as a result of the mutant hair follicles failing to undergo programmed regression. Sonic hedgehog (Shh) was only detected in Smad4-mutant hair follicles at the catagen stage. Seventy percent of Smad4(co/co); K5-Cre mice developed spontaneous tumors within 12 months of birth. c-Myc and cyclin D1 were up-regulated whereas p21 and p27 expressions were decreased, which correlated with the epidermal hyperplasia in Smad4 mutants. Interestingly, coordinated deletion of the Smad4 and PTEN genes resulted in accelerated hair loss and skin tumor formation, suggesting that Smad4 and PTEN act synergistically to regulate epidermal proliferation and differentiation. All of our data indicate that Smad4 is essential for catagen induction and acts as a critical suppressor in skin tumorigenesis.

Topics: Alopecia; Animals; Epidermis; Gene Deletion; Hair Follicle; Mice; PTEN Phosphohydrolase; Skin; Skin Neoplasms; Smad4 Protein; Transforming Growth Factor beta

Human hair follicles, which are distributed in various and specific sites of the body, appear to have an inherited susceptibility for androgen-dependent growth. Beard, axillary, and frontal scalp dermal papilla cells (DPC) were recently shown to possess the characteristics of androgen target cells. These DPC show strong expression of androgen receptors, and the expression of type II 5alpha reductase is restricted to beard and frontal scalp DPC. These findings suggest that DPC mediate the signals of androgen to follicular epithelial cells in a paracrine fashion. We developed an in vitro co-culture system using DPC and keratinocytes (KC) to characterize the mode of androgen action in human hair follicles. Androgen significantly stimulated the proliferation of KC co-cultured with beard DPC, indicating that beard DPC produce androgen-dependent diffusible growth factors. Insulin-like growth factor-I was identified as one of the androgen-dependent paracrine growth factors produced by beard DPC. We also identified the inhibitory role of androgen on the growth of KC co-cultured with DPC from androgenetic alopecia (AGA) when the DPC were transfected with an expression vector encoding the androgen receptor. This growth suppression of KC was mediated by transforming growth factor-beta1 (TGF-beta1) derived from DPC of AGA, suggesting that TGF-beta1 is a paracrine mediator for AGA.

Topics: Alopecia; Androgens; Animals; Cells, Cultured; Hair; Hair Follicle; Humans; Insulin-Like Growth Factor I; Keratinocytes; Mesoderm; Paracrine Communication; Receptors, Androgen; Transforming Growth Factor beta

In this study, it was investigated how estrogens (17-beta-estradiol, E2) affect the estrogen receptor (ER) expression and gene regulation of male versus female human scalp hair follicles in vitro. Anagen VI follicles from frontotemporal scalp skin were microdissected and organ-cultured for up to 9 d in the presence of E2 (1-100 nm). Immunohistochemistry was performed for ERbeta-expression, known to be predominant in human scalp hair follicles, and for TGF-beta2-expression (as negative key hair growth modulator), and E2-responsive genes in organ-cultured human scalp hair follicles (48 h, 10 nM) were explored by cDNA microarray, using a commercial skin focus chip (Memorec, Cologne, Germany). The distribution pattern of ERbeta and TGF-beta2-immunoreactivity differed between male and female hair follicles after 48 h culture. Of 1300 genes tested, several genes were regulated sex-dependent differently. The study reveals substantial sex-dependent differences in the response of frontotemporal human scalp hair follicles to E2. Recognition and systematic dissection of the E2-dependent gene regulation will be crucial for the development of more effective, gender-tailored management strategies for female versus male pattern balding.

Topics: Alopecia; Estradiol; Estrogen Receptor beta; Estrogens; Female; Gene Expression Profiling; Gene Expression Regulation; Hair Follicle; Humans; Immunohistochemistry; In Vitro Techniques; Male; Oligonucleotide Array Sequence Analysis; Scalp; Sex Characteristics; Transforming Growth Factor beta

Pseudopelade of Brocq (PB) is an acquired progressive cicatricial alopecia which is characterized by some distinctive clinical features. It may represent either a distinct entity, i.e. an idiopathic primary scarring alopecia, or the end stage of various forms of scarring alopecia such as discoid lupus erythematosus (DLE) or lichen planopilaris (LPP).. The aim of the study was to evaluate a set of patients with a clinically defined PB, to ascertain whether their PB was idiopathic or secondary, and then to study the phenotype of the inflammatory infiltrate and the presence of any fibrogenic and antifibrogenic cytokines to identify idiopathic or secondary forms in more detail.. Twelve female patients with PB were studied by means of histology, direct immunofluorescence (DIF) and immunohistochemistry, by using monoclonal antibodies to cell markers (lymphocyte subtypes, Langerhans cells, macrophages, fibroblasts, mastocytes and activation markers) and fibrogenic and antifibrogenic cytokines.. Using histology and DIF, we diagnosed two cases as DLE and three cases as LPP. Seven cases had nonspecific histology or DIF appearances and were classified as noncharacterized pseudopelade (NCPB). Two major phenotypic patterns of dermal infiltrate were identified by immunohistochemistry. These were: (i) a conspicuous infiltrate of CD3+ cells with a high CD4+/CD8+ ratio, variable numbers of macrophages, mast cells and fibroblasts always fewer than lymphocytes; (ii) an infiltrate of CD3+ cells with variable CD4+/CD8+ ratio and conspicuous amounts of macrophages, mast cells and fibroblasts, more numerous than infiltrating lymphocytes. The first pattern was typical of DLE and LPP, the second one was typical of NCPB. Fibrogenic cytokines were observed in all cases, but basic fibroblastic growth factor (bFGF) and transforming growth factor (TGF)-beta were more strongly expressed in NCPB. Interferon (IFN)-gamma was found in LPP.. In our PB patients we identified five of 12 secondary PB and seven of 12 idiopathic PB by means of histology and DIF. The phenotypic pattern of infiltration allowed us to further differentiate secondary (richer in lymphocytes) from idiopathic PB (richer in resident cells). The pattern of cytokine expression showed the presence of fibrogenic molecules (interleukins 4 and 6, bFGF and TGF-beta) in all cases, suggesting the involvement of mechanisms mediated by T-helper 2 and 3 cytokines in PB.

Topics: Adult; Aged; Alopecia; Cytokines; Female; Fibroblast Growth Factor 2; Humans; Immunohistochemistry; Interferon-gamma; Interleukin-4; Interleukin-6; Middle Aged; Scalp; Skin; T-Lymphocytes, Helper-Inducer; Transforming Growth Factor beta

Androgenic alopecia (AGA) is the most common type of baldness in men. Although etiological studies have proved that androgen is one of the causes of this symptom, the defined molecular mechanism underlying androgen-related actions remains largely unknown.. To clarify the difference in the gene expression profile of dermal papilla cells (DPCs) in skin affected by baldness.. DNA macroarray study was carried out on cultured DPCs from AGA skin comparing with DPCs from skin that is not affected by baldness.. From DNA macroarray analysis, we observed that 107 of the 1185 analyzed genes had differing expression levels. A marked difference was observed in the decreased gene expression of BMP2 and ephrin A3 and up-regulated in NT-4 gene. In order to clarify the roles of BMP2 and ephrin A3 in the hair follicles, we examined the proliferation of hair follicle keratinocyte and expression of a hair acidic keratin gene. Both BMP2 and ephrin A3 raised the proliferation rate of the outer root sheath cells (ORSCs) and induced gene expression in acidic hair keratin 3-II.. These results lead us to the hypothesis that both BMP2 and ephrin A3 function as hair growth promoting factors in the hair cycle.

Topics: Alopecia; Androgens; Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Cell Proliferation; Dermis; Dose-Response Relationship, Drug; Down-Regulation; Ephrin-A3; Gene Expression Regulation; Hair Follicle; Humans; Keratins; Male; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Reverse Transcriptase Polymerase Chain Reaction; Skin; Transforming Growth Factor beta; Up-Regulation

We attempted to establish a coculture model of human dermal papilla cells (DPCs) from androgenetic alopecia (AGA) and keratinocytes (KCs) to study the pathomechanism of AGA. Since expression of mRNA for the androgen receptor (AR) decreased during subcultivation of DPCs in vitro, we transiently transfected the AR expression vector into the DPCs and cocultured them with KCs. In this coculture, androgen inhibited the growth of KCs by 50%, indicating that the DPCs produce diffusible growth suppressive factors into the medium in an androgen-dependent manner. Since recently increasing evidence has shown the importance of transforming growth factor-beta1 (TGF-beta1) in hair growth, we further examined the concentration of TGF-beta1 in this coculture medium after androgen treatment by ELISA assays. The results showed that androgen treatment increased the secretion of TGF-beta1 into the conditioned medium. Moreover, neutralizing anti-TGF-beta1 antibody reversed the inhibition of KC proliferation. Thus, we suggest that androgen-inducible TGF-beta1 derived from DPCs mediates hair growth suppression in AGA.

Topics: Alopecia; Androgens; Antibodies; Cell Division; Cells, Cultured; Coculture Techniques; Culture Media, Conditioned; Enzyme-Linked Immunosorbent Assay; Humans; Keratinocytes; Metribolone; Osmolar Concentration; Receptors, Androgen; Skin; Transfection; Transforming Growth Factor beta; Transforming Growth Factor beta1

We attempted establishing an in vitro coculture system by using human dermal papilla cells (DPCs) from androgenetic alopecia (AGA) and keratinocytes (KCs) to explore the role of androgens in hair growth regulation. Androgen showed no significant effect on the growth of KCs when they were cocultured with DPCs from AGA. Because the expressions of mRNA of androgen receptor (AR) decreased during subcultivation of DPCs in vitro, we transiently transfected the AR expression vector into the DPCs and cocultured them with KCs. In this modified coculture, androgen significantly suppressed the growth of KCs by approximately 50%, indicating that overexpression of AR can restore the responsiveness of the DPCs to androgen in vivo. We found that androgen stimulated the expression of TGF-beta1 mRNA in the cocultured DPCs. ELISA assays demonstrated that androgen treatment increased the secretion of both total and active TGF-beta1 in the conditioned medium. Moreover, the neutralizing anti-TGF-beta1 antibody reversed the androgen-elicited growth inhibition of KCs in a dose-dependent manner. These findings suggest that androgen-inducible TGF-beta1 derived from DPCs of AGA is involved in epithelial cell growth suppression in our coculture system, providing the clue to understand the paradoxical effects of androgens for human hair growth.

Topics: Alopecia; Cell Division; Coculture Techniques; Dermis; Hair; Hair Follicle; Humans; Keratinocytes; Metribolone; Models, Biological; Receptors, Androgen; RNA, Messenger; Testosterone Congeners; Transfection; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

To study the role of transforming growth factor type beta1 (TGFbeta1) in epidermal growth control and disease, we have generated a conditional expression system by using the bovine keratin 5 promoter to drive expression of the tetracycline-regulated transactivators tTA and rTA, and a constitutively active mutant of TGFbeta1 linked to the tetO target sequence for the transactivator. This model allows for induction or suppression of exogenous TGFbeta1 with oral doxycycline. Maximal expression of TGFbeta1 during gestation caused embryonic lethality, whereas partial suppression allowed full-term development with neonatal lethality characterized by runting, epidermal hypoproliferation, and blocked hair follicle growth. With complete suppression, phenotypically normal double transgenic (DT) mice were born. Acute induction of TGFbeta1 in the epidermis of adult mice inhibited basal and follicular keratinocyte proliferation and reentry of telogen hair follicles into anagen. However, chronic expression of TGFbeta1 in adult DTs caused severe alopecia characterized by epidermal and follicular hyperproliferation, apoptosis, as well as dermal fibrosis and inflammation. Readministration of doxycycline to tTA DT mice caused hair regrowth within 14 days. The mRNA and protein for Smad7, an inhibitor of TGFbeta signaling, were up-regulated in the epidermis and hair follicles of alopecic skin and rapidly induced in rTA mice in parallel with the TGFbeta1 transgene, suggesting that the hyperproliferative phenotype may result in part from development of a sustained negative feedback loop. Thus, this conditional expression system provides an important model for understanding the role of TGFbeta1 during development, in normal skin biology, and in disease.

Topics: Alopecia; Animals; Animals, Newborn; Apoptosis; Base Sequence; Cell Division; DNA Primers; DNA-Binding Proteins; Doxycycline; Gene Expression Regulation, Developmental; Genes, Lethal; Hyperplasia; Keratinocytes; Mice; Smad7 Protein; Trans-Activators; Transforming Growth Factor beta