Einleitung: Für α-MSH werden neben der Regulation der Hautpigmentation anti-inflammatorische Eigenschaften u.a. durch Bindung an seinen MC1-Rezeptor diskutiert. So bewirkte die tägliche Injektion von α-MSH im murinen DSS-Modell eine signifikant geringere Gewichtsabnahme und einen deutlich milderen Verlauf der Entzündung im Darm selbst. Der tatsächliche Wirkort und Wirkmechanismus von α-MSH im gastro-intestinalen Trakt ist jedoch bislang unbekannt.

The neuropeptide a-melanocyte-stimulating hormone (alpha-MSH) is a well-known mediator of skin pigmentation. More recently, it has been shown that a-MSH also exerts a strong anti-inflammatory and immunosuppressive activity. To elucidate the mechanisms underlying alpha-MSH-induced immunosuppression, we investigated whether a-MSH affects dendritic cell/T cell communication, as especially this interaction has an important role in the regulation of immune responses. Here, we show that a-MSH, by binding to MC-1R, induced tolerogenic dendritic cells, which were capable of expanding CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) in vitro, as well as in vivo. Notably, those a-MSH-induced Tregs were functional as they efficiently inhibited cutaneous contact allergy and ongoing psoriasis-like skin inflammation in mice. Furthermore, alpha-MSH induced tolerogenic dendritic cells capable of generating functional Tregs in human blood. Interestingly, human Tregs expanded via alpha-MSH-stimulated dendritic cells suppressed the proliferation and cytokine secretion of pathogenic T-helper-17 (Th17) cells from individuals with psoriasis. Taken together, these data indicate that a-MSH induced immunosuppressive Tregs in vitro and in vivo, which inhibited disease progression in a mouse model of psoriasis-like skin inflammation and suppressed the activation and proliferation of effector T cells from subjects with psoriasis. Journal of Investigative Dermatology (2012) 132, 1814-1824; doi:10.1038/jid.2012.59; published online 15 March 2012

Treatment options for inflammatory bowel disease (IBD) are incompletely helpful, and surgery is often needed. One promising class of future therapeutic agents for IBD is melanocortin-related peptides, which exhibit potent immunomodulatory effects. We investigated KdPT, a tripeptide derivative of the C-terminus of α-melanocyte-stimulating hormone, as an anti-inflammatory small molecule in vivo and in vitro. Intestinal inflammation was studied after oral administration of dextran sodium sulfate and in IL-10 gene-deficient mice. The effects of KdPT on key colonic epithelial cell functions were studied in vitro and in vivo by evaluating proliferation, wound healing, transepithelial resistance, and expression of tight junction proteins. Melanin assays were performed to determine the melanotropic effects of KdPT. KdPT-treated animals showed markedly reduced severity of inflammation in both colitis models. In colonic epithelial cells, KdPT increased proliferation, accelerated closure of wounds, and improved transepithelial electrical resistance after stimulation with interferon-γ/tumor necrosis factor-α. Moreover, treatment with KdPT also prevented the loss of tight junction protein expression and improved barrier function in vivo. KdPT acted independently of IL-1 receptor type I in vivo and did not affect melanogenesis in vitro. KdPT is capable of attenuating the course of experimental colitis in different models and maintains epithelial cell function. Furthermore, KdPT does not induce pigmentation, emphasizing the potential of this small molecule for the future treatment of IBD.

Einleitung/Ziel: Das Melanokortin-verwandte Tripeptid KdPT vermittelt anti-inflammatorische Effekte in vivo and in vitro. Ziel der Studie war zu untersuchen, ob die intrazelluläre Aufnahme von KdPT Transporter-vermittelt ist und den Einfluss auf die intestinale Barriere zu überprüfen.

BACKGROUND:The neuropeptide alpha-melanocyte-stimulating hormone is well known as a mediator of skin pigmentation. More recently, it has been shown that alpha-melanocyte-stimulating hormone also plays pivotal roles in energy homeostasis, sexual function, and inflammation or immunomodulation. Alpha-melanocyte-stimulating hormone exerts its antiinflammatory and immunomodulatory effects by binding to the melanocortin-1 receptor, and since T cells are important effectors during immune responses, we investigated the effects of alpha-melanocyte-stimulating hormone on T cell function.METHODOLOGY/PRINCIPAL FINDINGS:T cells were treated with alpha-melanocyte-stimulating hormone, and subsequently, their phenotype and function was analyzed in a contact allergy as well as a melanoma model. Furthermore, the relevance of alpha-melanocyte-stimulating hormone-mediated signaling for the induction of cytotoxicity was assessed in CD8(+) T cells from melanoma patients with functional and nonfunctional melanocortin-1 receptors. Here we demonstrate that the melanocortin-1 receptor is expressed by murine as well as human CD8(+) T cells, and we furthermore show that alpha-melanocyte-stimulating hormone/melanocortin-1 receptor-mediated signaling is critical for the induction of cytotoxicity in human and murine CD8(+) T cells. Upon adoptive transfer, alpha-melanocyte-stimulating hormone-treated murine CD8(+) T cells significantly reduced contact allergy responses in recipient mice. Additionally, the presented data indicate that alpha-melanocyte-stimulating hormone via signaling through a functional melanocortin-1 receptor augmented antitumoral immunity by up-regulating the expression of cytotoxic genes and enhancing the cytolytic activity in tumor-specific CD8(+) T cells.CONCLUSIONS/SIGNIFICANCE:Together, these results point to an important role of alpha-melanocyte-stimulating hormone in MHC class I-restricted cytotoxicity. Therefore, treatment of contact allergies or skin cancer with alpha-melanocyte-stimulating hormone or other more stable agonists of melanocortin-1 receptor might ameliorate disease or improve antitumoral immune responses.

Background: Colorectal cancer is one of the most serious complications of ulcerative colitis (UC) and the risk of UC-associated neoplasia increases as the region and duration of the disease increase.As we have shown previously, the selective cyclooxygenase (COX)-2 inhibitor is effective in diminishing carcinogenesis in an murine model of UC (DDW 2006).1However, this might exacerbate dextran sulfate sodium (DSS) colitis in mice.The selective COX-2 inhibitor Etodolac is marketed as a racemic mixture of the R-and S-enantiomers that are not metabolically interconvertible.The biochemical and pharmacological effects of Etodolac are due to the S-enantiomer, while R-enantiomer lacks COX-inhibitory activity.Therefore, R-Etodolac has potential advantage of avoiding COX-2 inhibitory adverse effects.In this study, we evaluated the effect of R-Etodolac on colitis-related mouse colon carcinogenesis.Methods: The mice received 1,2-dimethlhydrazine (DMH) at a dose of 20mg/kg body wt subcutaneously three times within 1 week of reaching 6 weeks of age.Starting 1 week after the DMH injection, chronic colitis was induced in mice by administration of 2 cycles of DSS (each cycle: 3% DSS for 7 days and then distilled water for 14 days).The mice were killed 28 days after the completion of the 2 cycles.The mice were divided into the following groups: group A served as a disease control; group B received low (2mg/kg) dose of R-Etodolac every 3 days by oral gavage during the whole period; group C received high (10mg/ kg) dose of R-Etodolac every 3 days by oral gavage during the whole period; group D received no agents including DSS and served as a normal control.Results: The administration of R-Etodolac decreased the disease activity index during the administration cycle of DSS.The mean number of tumors was 17.8 in group A, 15.2 in group B and 6.0 in group C. In group C, R-Etodolac significantly suppressed the occurrence of neoplasia (p<0.05).Strong COX-2 expression was detected by immunohistochemistry in the neoplastic lesions while E-cadherin expression was not observed.Although treatment of R-Etodolac unaffected to the COX-2 expression, it was found that R-Etodolac significantly enhanced the expression of E-cadherin in the neoplastic lesions and background mucosa (i.e.lesion-free colon).Conclusion: The administration of R-Etodolac exerts a suppressive effect on the development of neoplasia in a murine model of DSS induced colitis without exacerbation of the colitis.These results suggest that R-Etodolac could be useful in the prevention of UC-associated neoplasia.1.

During the last two decades a significant number of investigations has established the fact that alpha-Melanocyte-stimulating hormone (alpha-MSH) is a potent anti-inflammatory mediator. The anti-inflammatory effects of alpha-MSH can be elicited via melanocortin receptors (MC-Rs) broadly expressed in a number of tissues ranging from the central nervous system to cells of the immune system and on resident somatic cells of peripheral tissues. alpha-MSH affects various pathways regulating inflammatory responses such as NF-kappa B activation, expression of adhesion molecules, inflammatory cytokines, chemokine receptors, T-cell proliferation and activity and inflammatory cell migration. In vivo alpha-MSH has been shown to be anti-inflammatory as well in animal models of fever, irritant and allergic contact dermatitis, cutaneous vasculitis, fibrosis, in ocular, gastrointestinal, brain and allergic airway inflammation and arthritis. A broad range of effects of alpha-MSH exerted beyond the field of inflammation, its pigmentory capacity being only the most visible aspect, has been one of the major impediments limiting the use of alpha-MSH in human inflammatory disorders. Interestingly KPV, C-terminal tripeptide of alpha-MSH, which lacks the entire sequence motif required for binding to any of the known MC-Rs, retains almost all of the anti-inflammatory capacity of the full hormone, but in its activities display a lack of any pigmentory action. While the exact signaling mechanism utilized by KPV and related peptides currently is unknown it has been demonstrated already that significant similarities between anti-inflammatory signaling of alpha-MSH and those short peptides exist. These alpha-MSH related tripeptides thus may be useful alternatives for anti-inflammatory peptide therapy. KdPT, a derivative of KPV corresponding to IL-1 beta(193-195), currently is emerging as another tripeptide with potent anti-inflammatory effects. A more limited spectrum of biologic activities, potentially advantageous physicochemical, pharmacokinetic and pharmacodynamic properties as well as the expectation of low costs for pharmaceutical production make these agents interesting candidates for the treatment of immune-mediated inflammatory skin and bowel diseases, allergic asthma and arthritis.

British Journal of DermatologyVolume 161, Issue 6 p. 1400-1403 Immunomodulatory effects of the α-melanocyte-stimulating hormone-related tripeptide K(D)PT on human scalp hair follicles under proinflammatory conditions Correction(s) for this article Corrigenda Volume 161Issue 6British Journal of Dermatology pages: 1423-1423 First Published online: November 17, 2009 K.C. Meyer, K.C. Meyer Department of Dermatology, University of Lübeck,Ratzeburger Allee 160, D-23538 Lübeck, GermanySearch for more papers by this authorE. Bodó, E. Bodó Department of Dermatology, University of Lübeck,Ratzeburger Allee 160, D-23538 Lübeck, Germany Agricultural and Molecular Research Institute,College of Nyíregyháza, Nyíregyháza, HungarySearch for more papers by this authorT. Brzoska, T. Brzoska Dr August Wolff GmbH & Co. KG Arzneimittel,Bielefeld, Germany Department of Dermatology, University of Münster,Münster, GermanySearch for more papers by this authorC. Abels, C. Abels Department of Dermatology, University of Münster,Münster, GermanySearch for more papers by this authorR. Paus, R. Paus Department of Dermatology, University of Lübeck,Ratzeburger Allee 160, D-23538 Lübeck, Germany School of Translational Medicine, University of Manchester,Manchester, U.KSearch for more papers by this author K.C. Meyer, K.C. Meyer Department of Dermatology, University of Lübeck,Ratzeburger Allee 160, D-23538 Lübeck, GermanySearch for more papers by this authorE. Bodó, E. Bodó Department of Dermatology, University of Lübeck,Ratzeburger Allee 160, D-23538 Lübeck, Germany Agricultural and Molecular Research Institute,College of Nyíregyháza, Nyíregyháza, HungarySearch for more papers by this authorT. Brzoska, T. Brzoska Dr August Wolff GmbH & Co. KG Arzneimittel,Bielefeld, Germany Department of Dermatology, University of Münster,Münster, GermanySearch for more papers by this authorC. Abels, C. Abels Department of Dermatology, University of Münster,Münster, GermanySearch for more papers by this authorR. Paus, R. Paus Department of Dermatology, University of Lübeck,Ratzeburger Allee 160, D-23538 Lübeck, Germany School of Translational Medicine, University of Manchester,Manchester, U.KSearch for more papers by this author First published: 17 November 2009 https://doi.org/10.1111/j.1365-2133.2009.09427.xCitations: 12 Ralf Paus.E-mail: Ralf.Paus@uk-sh.de Conflicts of interest: This study was supported in part by a grant from the pharmaceutical company Dr August Wolff Arzneimittel GmbH & Co. KG, Bielefeld, Germany that holds a commercial interest in K(D)PT. Two of the coauthors of this study (T.B., C.A.) are employees of this company. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume161, Issue6December 2009Pages 1400-1403 RelatedInformation

Various glutamate receptors have been described in both keratinocytes and melanocytes. L-Glutamate is the physiological agonist of the glutamate receptor family. The source of this transmitter had not yet been identified. In normal human epidermal keratinocytes (NHEK) and HaCaT-keratinocytes, cell supernatants were sampled in various stages of cell density and the l-glutamate content photometrically determined. The following examination time-points were defined: non-confluent (ca. 33%), subconfluent (ca. 70%) and confluent (90-100%). The L-glutamate concentration originally in the culture medium was 14.7 mg/l (0.1 mm/l). The L-glutamate concentration in the cell supernatant increased in NHEK with increasing cell density: non-confluent 39.9 + or - 4 mg/l, subconfluent 60.6 + or - 15.8 mg/l, confluent 100.7 + or - 33.2 mg/l. A linear increase of L-glutamate concentration was also found for HaCaT cells. The investigations show that keratinocytes are capable of producing and releasing L-glutamate. Thus they are a source of L-glutamate which acts as a transmitter on epidermal glutamate receptors.

4-hydroperoxicyclophosphamide dystrophic catagen pathway 17-β estradiol hair follicle prednisolone Chemotherapy-induced hair follicle (HF) dystrophy and alopecia are major unresolved problems in clinical oncology (Wang et al., 2006Wang J. Lu Z. Au J.L. Protection against chemotherapy-induced alopecia.Pharm Res. 2006; 2003: 2505-2514Google Scholar; Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar; Lemieux et al., 2007Lemieux J. Maunsell E. Provencher L. Chemotherapy-induced alopecia and effects on quality of life among women with breast cancer: a literature review.Psychooncology. 2007; 17: 317-328Google Scholar). Although the study of cyclophosphamide-induced alopecia in mice has provided important pointers to potentially useful agents that might deserve clinical testing and has allowed us to dissect some of the basic pathobiological mechanisms (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar, Paus et al., 1996Paus R. Schilli M.B. Handjiski B. Menrad A. Henz B.M. Plonka P. Topical calcitriol enhances normal hair regrowth but does not prevent chemotherapy-induced alopecia in mice.Cancer Res. 1996; 56: 4438-4443Google Scholar; Schilli et al., 1998Schilli M.B. Paus R. Menrad A. Reduction of intrafollicular apoptosis in chemotherapy-induced alopecia by topical calcitriol-analogs.J Invest Dermatol. 1998; 111: 598-604Google Scholar; Botchkarev et al., 2000Botchkarev V.A. Komarova E.A. Siebenhaar F. Botchkareva N.V. Komarov P.G. Maurer M. et al.p53 is essential for chemotherapy-induced hair loss.Cancer Res. 2000; 60: 5002-5006Google Scholar; Ohnemus et al., 2004Ohnemus U. Unalan M. Handjiski B. Paus R. Topical estrogen accelerates hair regrowth in mice after chemotherapy-induced alopecia by favoring the dystrophic catagen response pathway to damage.J Invest Dermatol. 2004; 122: 7-13Google Scholar; Sredni et al., 2004Sredni B. Gal R. Cohen I.J. Dazard J.E. Givol D. Gafter U. et al.Hair growth induction by the Tellurium immunomodulator AS101: association with delayed terminal differentiation of follicular keratinocytes and ras-dependent up-regulation of KGF expression.FASEB J. 2004; 18: 400-402Google Scholar; Hendrix et al., 2005Hendrix S. Handjiski B. Peters E.M. Paus R. A guide to assessing damage response pathways of the hair follicle:lessons from cyclophosphamide-induced alopecia in mice.J Invest Dermatol. 2005; 125: 42-51Google Scholar), the—as yet unmet—challenge is to develop a convincing preclinical assay system that allows one to predict how chemotherapy-treated human scalp HFs respond to the various candidate alopecia protectants that have surfaced from rodent studies. Recently, we established a human in vitro model for studying chemotherapy-induced HF dystrophy (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar), which reliably re-produces the HF damage seen in vivo. In this assay, cyclophosphamide, a classical cytostatic agent that frequently causes chemotherapy-induced alopecia in clinical medicine (Braun-Falco, 1961Braun-Falco O. Klinik und Pathomechanismus der Endoxan-Alopecie als Beitrag zum Wesen cytostatischer Alopecien.Arch Klin Exp Dermatol. 1961; 212: 194-216Google Scholar) is replaced by one of its active toxic metabolites normally generated in vivo, 4-hydroperoxycyclophosphamide (4-HC). Using this human model we could show that 4-HC profoundly inhibits hair shaft elongation, matrix keratinocyte proliferation, induces massive apoptosis of matrix keratinocytes and melanin clumping (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar). Chemotherapy-induced HF damage follows two distinct pathways: dystrophic anagen and dystrophic catagen (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar; Hendrix et al., 2005Hendrix S. Handjiski B. Peters E.M. Paus R. A guide to assessing damage response pathways of the hair follicle:lessons from cyclophosphamide-induced alopecia in mice.J Invest Dermatol. 2005; 125: 42-51Google Scholar). During the dystrophic anagen pathway, the hair shaft is shed, and the follicle undergoes an incomplete “primary recovery” during an (paradoxically prolonged!) anagen phase. This is followed by a retarded “secondary recovery” during which a normal hair shaft is generated in the subsequent anagen phase. By contrast, HFs that undergo the dystrophic catagen (DC) pathway (for example, in response to a higher dose of chemotherapy) immediately enter into a dystrophic catagen stage, followed by an abnormally shortened telogen phase, and thus rapidly enter into secondary recovery by premature induction of a new anagen phase. Therefore, even though it is clinically associated with the most dramatic effluvium/alopecia, the DC pathway leads to the fastest, complete HF recovery (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar; Hendrix et al., 2005Hendrix S. Handjiski B. Peters E.M. Paus R. A guide to assessing damage response pathways of the hair follicle:lessons from cyclophosphamide-induced alopecia in mice.J Invest Dermatol. 2005; 125: 42-51Google Scholar). In mice, in vivo, topical application of steroid hormones (dexamethasone, calcitriols, or 17-β-estradiol (E2)) before and after systemic cyclophosphamide administration potently promotes the DC pathway. Thus, these steroid hormones greatly enhance the initial alopecia, but maximally accelerate the regrowth of normally pigmented hair shafts as HF “secondary recovery” is optimally enhanced (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar; Schilli et al., 1998Schilli M.B. Paus R. Menrad A. Reduction of intrafollicular apoptosis in chemotherapy-induced alopecia by topical calcitriol-analogs.J Invest Dermatol. 1998; 111: 598-604Google Scholar; Ohnemus et al., 2004Ohnemus U. Unalan M. Handjiski B. Paus R. Topical estrogen accelerates hair regrowth in mice after chemotherapy-induced alopecia by favoring the dystrophic catagen response pathway to damage.J Invest Dermatol. 2004; 122: 7-13Google Scholar). Therefore, we were interested in studying how E2 or a combination of E2 with glucocorticosteroids would affect 4-HC-induced human scalp HF damage in our new human in vitro model (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar), and whether there are any indications where these steroid hormones, alone or in combination, promote the DC pathway. We purposely selected E2 and a combination with prednisolone (P) for further study, as the topical application of both has a long tradition of clinical application in central European dermatology for hair loss management (Abadjieva, 2000Abadjieva T.I. Treatment of androgenetic alopecia in females in reproductive age with topical estradiol benzoate, prednisolone and salicylic acid.Folia Med. 2000; 42: 26-29Google Scholar; Wüstner and Orfanos, 1974Wüstner H. Orfanos C.E. Alopecia androgenetica and its local treatment with estrogen- and corticosteroid externa.Z Hautkr. 1974; 49: 879-888Google Scholar). Due to the extremely limited number of available human scalp HFs, we opted for testing of one E2 and P concentration, and selected 10-7M after selected (Kanda and Watanabe, (2004)Kanda N. Watanabe S. 17-beta estradiol stimulates the growth of human keratinocytes by inducing cyclin D2 expression.J Invest Dermatol. 2004; 123: 319-328Google Scholar). Anagen VI HFs were isolated from normal human scalp skin from healthy female patients undergoing routine face-lift surgery (obtained after ethics committee approval and written consent from patient, adhering to Helsinki guidelines) as described (Philpott et al., 1990Philpott M.P. Green M.R. Kealey T. Human hair growth in vitro.J Cell Sci. 1990; 97: 463-471Google Scholar). We received HFs (10–18 HFs per group) from female patients (all 50-year old). Isolated HFs were maintained in supplemented, serum-free Williams' E medium and treated with 4-HC (30μM) as described (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar). Before the first 4-HC treatment, follicles were incubated with E2/P (both 10-7M) or their combination for 12 hours and then co-cultured with or without (vehicle) 4-HC for further 3 days. After cryoembedding of cultured HFs, 6-μm thick cryostat sections were prepared for histology. HF morphology and HF cycle staging were performed on Masson–Fontana stained cryosections as described (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar). First, we assessed the impact of E2/P on the 4-HC-induced inhibition of human hair shaft elongation in vitro. Hair shaft length was measured every second day on each individual HF. As expected (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar), 4-HC significantly inhibited hair shaft elongation (Figure 1a). As reported before (Conrad et al., 2004Conrad F. Ohnemus U. Bodo E. Bettermann A. Paus R. Estrogens and human scalp hair growth-still more questions than answers.J Invest Dermatol. 2004; 122: 840-842Google Scholar), E2 alone also caused a significant reduction of hair shaft growth (Figure 1a). E2 further enhanced 4-HC-induced hair shaft inhibition. This inhibitory effect of E2 was further augmented by P, whereas P alone did not alter hair shaft elongation significantly (Figure 1a). Next, we investigated whether this inhibition was accompanied by altered HF cycling in vitro, as one of the key abnormalities of cyclophosphamide-induced alopecia in vivo is premature anagen VI termination and massive, apoptosis-driven HF regression (catagen), both in humans (Braun-Falco, 1961Braun-Falco O. Klinik und Pathomechanismus der Endoxan-Alopecie als Beitrag zum Wesen cytostatischer Alopecien.Arch Klin Exp Dermatol. 1961; 212: 194-216Google Scholar) and in mice (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar). Although approximately 80% of vehicle-treated follicles still displayed anagen VI morphology, 4-HC treatment reduced this number to 10%, as expected (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar). Interestingly, this premature catagen induction by 4-HC was further enhanced by E2 and P co-administration (Figure 1b). After combined treatment with E2 and P, HFs even showed late catagen morphology (Figure 1b), which is observed only very rarely in spontaneously regressing human scalp HFs of the Philpott assay. This clearly indicates that E2 and P, by themselves, are potent catagen inducers in organ-cultured human anagen HFs, and further promote their 4-HC-driven premature catagen transformation. The 4-HC-induced hair cycle changes were associated with the expected abnormal melanin production, transfer, and deposition, as an indicator of substantial HF dystrophy (Tobin et al., 1998Tobin D.J. Hagen E. Botchkarev V.A. Paus R. Do hair bulb melanocytes undergo apoptosis during hair follicle regression (catagen)?.J Invest Dermatol. 1998; 111: 941-947Google Scholar; Hendrix et al., 2005Hendrix S. Handjiski B. Peters E.M. Paus R. A guide to assessing damage response pathways of the hair follicle:lessons from cyclophosphamide-induced alopecia in mice.J Invest Dermatol. 2005; 125: 42-51Google Scholar; Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar). However, we failed to observe a significant, well-reproducible modulatory effect on melanin clumping/transfer by E2/P in this assay. E2/P increased significant melanin clumping only in the HFs of a single patient, indicating a greater level of HF dystrophy by E2/P. Finally, we tested whether the hair shaft elongation-inhibitory and catagen-promoting effects of E2 were associated with a significant alteration in the number of the proliferating and/or apoptotic matrix keratinocytes. For the simultaneous detection of proliferating and apoptotic keratinocytes, the Ki-67/TUNEL double staining was used (Bodó et al., 2007Bodó E. Tobin D.J. Kamenisch Y. Bíró T. Berneburg M. Funk W. et al.Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy.Am J Pathol. 2007; 171: 1153-1167Google Scholar). As shown in Figures 1c and d, quantitative immunohistomorphometry revealed that E2 alone as well as E2/P, but not P alone, significantly inhibited human hair matrix keratinocyte proliferation and enhanced their entry into apoptosis. Furthermore, co-administration of E2 or E2/P with 4-HC augmented the proliferation–inhibitory effect of 4-HC on human hair matrix keratinocytes. These data are in line with the hair shaft elongation, catagen induction, and HF dystrophy observations summarized above. Although this limited pilot study calls for follow-up testing with more HFs from a larger number of individuals of both sexes, as well as for full dose–response assays, and reflects a systemic mode of test agent application, not a topical one, it already invites to the following clinically important conclusions:Steroid hormones that are frequently employed in clinical dermatology, namely E2 and P, exert profound modulatory effects on human scalp HF growth, cycling, and hair shaft formation.The tested dose of E2 and P (10-7M) clearly promotes the DC pathway of response to chemotherapy-induced HF damage/dystrophy in normal human scalp HFs.This is the first evidence from a physiologically relevant human preclinical test system, which suggests that our corresponding observations and concepts in the murine system in vivo (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar; Ohnemus et al., 2004Ohnemus U. Unalan M. Handjiski B. Paus R. Topical estrogen accelerates hair regrowth in mice after chemotherapy-induced alopecia by favoring the dystrophic catagen response pathway to damage.J Invest Dermatol. 2004; 122: 7-13Google Scholar; Hendrix et al., 2005Hendrix S. Handjiski B. Peters E.M. Paus R. A guide to assessing damage response pathways of the hair follicle:lessons from cyclophosphamide-induced alopecia in mice.J Invest Dermatol. 2005; 125: 42-51Google Scholar), with which the current ones are well in line, are indeed relevant to the human system.The combined administration of E2 and P tends to further enhance the dystrophic catagen response pathway to chemotherapy-induced HF damage. Although the underlying molecular mechanisms are widely unknown, one could speculate which molecular pathways may be involved here. As reviewed by Ohnemus et al., 2006Ohnemus U. Unealan M. Inzunza J. Gustafsson J.A. Paus R. The hair follicle as an estrogen target and source.Endocr Rev. 2006; 27: 677-706Google Scholar, HFs serve as estrogen target tissue and estrogens reportedly alter gene expression of several hair cycle-relevant genes or signaling pathway members, that is, mitogen-activated protein kinase pathway, transforming growth factor/bone morphogenetic protein family, which may be involved in further catagen and apoptosis induction. Using the C57BL/6 mouse model for the study of chemotherapy-induced alopecia, we had found that topically applied steroid hormones, such as dexamethasone, calcitriol, and E2 that promote the “dystrophic catagen” pathway, in vivo, induce a more pronounced, massive initial alopecia, followed by a significantly accelerated regrowth of normally pigmented hair shafts (Paus et al., 1994Paus R. Handjiski B. Eichmuller S. Czarnetzki B.M. Chemotherapy-induced alopecia in mice. Induction by cyclophosphamide, inhibition by cyclosporine A, and modulation by dexamethasone.Am J Pathol. 1994; 144: 719-734Google Scholar, Paus et al., 1996Paus R. Schilli M.B. Handjiski B. Menrad A. Henz B.M. Plonka P. Topical calcitriol enhances normal hair regrowth but does not prevent chemotherapy-induced alopecia in mice.Cancer Res. 1996; 56: 4438-4443Google Scholar; Ohnemus et al., 2004Ohnemus U. Unalan M. Handjiski B. Paus R. Topical estrogen accelerates hair regrowth in mice after chemotherapy-induced alopecia by favoring the dystrophic catagen response pathway to damage.J Invest Dermatol. 2004; 122: 7-13Google Scholar; Hendrix et al., 2005Hendrix S. Handjiski B. Peters E.M. Paus R. A guide to assessing damage response pathways of the hair follicle:lessons from cyclophosphamide-induced alopecia in mice.J Invest Dermatol. 2005; 125: 42-51Google Scholar). As the tested steroid hormones also stimulated the “dystrophic catagen” pathway in organ-cultured human scalp HFs, it is reasonable to expect a similar clinical outcome after application of these test agents to human scalp in vivo: If similarly high doses of E2 and/or E2/P can be achieved after topical application as have been administered in the current organ culture system, one would have to predict that topical E2 and/or E2/P to chemotherapy-treated patients shortly before and after chemotherapy will—just as in mice—initially enhance the degree and velocity of hair loss. Subsequently, however, this treatment should greatly accelerate the regrowth of normally pigmented hair shafts, at least when cytostatic agents are employed that are comparable to cyclophosphamide. Naturally, only clinical trials will now be able to ascertain whether or not these preclinical pilot data are transferable to the in vivo situation. If this turns out to be the case, the central question will be: Can physicians really convince their patients who are threatened by the negative psychosocial implications of cyclophosphamide-induced alopecia (Wang et al., 2006Wang J. Lu Z. Au J.L. Protection against chemotherapy-induced alopecia.Pharm Res. 2006; 2003: 2505-2514Google Scholar; Lemieux et al., 2007Lemieux J. Maunsell E. Provencher L. Chemotherapy-induced alopecia and effects on quality of life among women with breast cancer: a literature review.Psychooncology. 2007; 17: 317-328Google Scholar) that it is a good strategy to promote the hair loss so as to allow for maximally accelerated HF recovery, that is, to even enhance the initial alopecia so as to, then, greatly shorten the time until normal hair regrowth? This work was supported by Dr August Wolff GmbH & Co. KG Arzneimittel, Bielefeld, Germany to RP. The authors are grateful to A Becker for excellent technical assistance.

Einleitung/Ziel: Melanokortine vermitteln potente immunmodulatorische Effekte im Rahmen entzündlicher Krankheitsbilder. Ziel der Studie war zu untersuchen, ob das Melanokortin-verwandte Tripeptid K(D)PT, H-Lys-(D)Pro-Thr-OH, antiinflammatorische Effekte in murinen Kolitismodellen besitzt und welche Mechanismen auf zellulärer Ebene beteiligt sind.