51
|
NF-κB: an essential transcription factor in psoriasis. J Dermatol Sci 2012; 69:89-94. [PMID: 23219896 DOI: 10.1016/j.jdermsci.2012.11.002] [Citation(s) in RCA: 212] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 11/01/2012] [Accepted: 11/03/2012] [Indexed: 01/15/2023]
Abstract
Nuclear factor kappa B (NF-κB) is a protein transcription factor that orchestrates inflammation and other complex biological processes. It is a key regulatory element in a variety of immune and inflammatory pathways, in cellular proliferation and differentiation and in apoptosis. Therefore NF-κB is a crucial mediator involved in the pathogenesis of psoriasis. Psoriasis, an inflammatory dermatosis, is marked by elevated levels of active, phosphorylated NF-κB. Genomic studies have also linked psoriasis with mediators in the NF-κB pathway. NF-κB has been hypothesized to connect the altered keratinocyte and immune cell behavior that characterizes the psoriatic milieu. Several anti-psoriatic therapies, including tumor necrosis factor-α blockers and glucocorticoids, reduce active NF-κB levels and related down-stream elements, and other biologics currently in development, including interleukin-17 blockers, may also target this pathway. Compounds that specifically target NF-κB signaling may be developed as novel therapeutics for chronic inflammatory disorders including psoriasis. However, chronic NF-κB inhibition could also result in immunodeficiencies. Therefore, a delicate balance must be found that maximizes therapeutic potential while limiting harmful effects, and may be achieved through several possible approaches, including localized therapy, selective inhibition of NF-κB signaling in pathologic cells, incomplete pathway inhibition or short treatment durations.
Collapse
|
52
|
A randomized, double-blind, placebo-controlled study to evaluate the addition of methotrexate to etanercept in patients with moderate to severe plaque psoriasis. Br J Dermatol 2012; 167:649-57. [PMID: 22533447 PMCID: PMC3504074 DOI: 10.1111/j.1365-2133.2012.11015.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Etanercept plus methotrexate combination therapy has not been adequately investigated in psoriasis. OBJECTIVES To evaluate etanercept plus methotrexate vs. etanercept monotherapy in patients with moderate to severe plaque psoriasis who had not failed prior methotrexate or tumour necrosis factor-inhibitor therapy. METHODS Patients received etanercept 50 mg twice weekly for 12 weeks followed by 50 mg once weekly for 12 weeks and were randomized 1 : 1 to receive methotrexate (7·5-15 mg weekly) or placebo. The primary endpoint was the proportion of patients achieving ≥75% improvement in Psoriasis Area and Severity Index (PASI 75) at week 24. RESULTS In total, 239 patients were enrolled in each arm. PASI 75 was significantly higher at week 24 for the combination therapy group compared with the monotherapy group (77·3% vs. 60·3%; P < 0·0001). Other PASI improvement scores at week 12 [PASI 75, 70·2% vs. 54·3% (P = 0·01); PASI 50, 92·4% vs. 83·8% (P = 0·01); and PASI 90, 34·0% vs. 23·1% (P = 0·03)] showed similar results as did week 24 PASI 50 (91·6% vs. 84·6%; P = 0·01) and PASI 90 (53·8% vs. 34·2%; P = 0·01). Significantly more patients receiving combination therapy than monotherapy had static Physician's Global Assessment of clear/almost clear at week 12 (65·5% vs. 47·0%; P = 0·01) and week 24 (71·8% vs. 54·3%; P = 0·01). Adverse events (AEs) were reported in 74·9% and 59·8% of combination therapy and monotherapy groups, respectively; three serious AEs were reported in each arm. CONCLUSIONS Combination therapy with etanercept plus methotrexate had acceptable tolerability and increased efficacy compared with etanercept monotherapy in patients with moderate to severe psoriasis.
Collapse
|
53
|
Successful treatment of moderate to severe plaque psoriasis with the PEGylated Fab' certolizumab pegol: results of a phase II randomized, placebo-controlled trial with a re-treatment extension. Br J Dermatol 2012; 167:180-90. [PMID: 22413944 DOI: 10.1111/j.1365-2133.2012.10941.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND Certolizumab pegol (CZP) is a PEGylated antitumour necrosis factor agent. OBJECTIVES To evaluate the efficacy and safety of CZP in patients with plaque psoriasis. METHODS In a randomized, placebo-controlled, double-blind study, 176 patients with moderate to severe psoriasis received placebo or CZP 400 mg at week 0 followed by placebo or CZP (200 or 400 mg) every other week until week 10. Co-primary endpoints were ≥ 75% improvement from baseline in Psoriasis Area and Severity Index (PASI 75) and a Physician's Global Assessment (PGA) of clear-almost clear at week 12. A re-treatment extension study was conducted in 71 CZP PASI 75 responders who relapsed during a 12- to 24-week observation period without treatment. RESULTS PASI 75 was achieved by 44/59 (75%), 48/58 (83%) and 4/59 (7%) patients in the CZP 200 mg, CZP 400 mg and placebo groups, respectively (P < 0·001 for both treatment arms vs. placebo). A PGA score of clear-almost clear was achieved by 53%, 72% and 2%, respectively (P < 0·001 for both treatment arms vs. placebo). In the re-treatment study median PASI scores were similar at week 12 in the first treatment and re-treatment periods for both CZP groups. Serious adverse events occurred in 3%, 5% and 2% of CZP 200 mg, CZP 400 mg and placebo patients, respectively. CONCLUSIONS Treatment with CZP significantly improved psoriasis at week 12. Similar efficacy was observed at week 12 in patients receiving re-treatment for loss of response after drug withdrawal.
Collapse
|
54
|
Efficacy and safety of briakinumab vs. etanercept and placebo in patients with moderate to severe chronic plaque psoriasis. Br J Dermatol 2011; 165:652-60. [PMID: 21574983 DOI: 10.1111/j.1365-2133.2011.10418.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The anti-interleukin-12/23p40 monoclonal antibody briakinumab has been shown in a phase II study to be effective psoriasis treatment. OBJECTIVES The aim of the current study was to assess the efficacy, safety and tolerability of briakinumab compared with etanercept and placebo in patients with moderate to severe chronic plaque psoriasis. METHODS In this phase III, 12-week study (M10-114, NCT00691964), 347 patients were randomized in a 2 : 2 : 1 ratio to receive 200 mg briakinumab at weeks 0 and 4 followed by 100 mg briakinumab at week 8 (n = 138); 50 mg of etanercept twice weekly 3-4 days apart at weeks 0-11 (n = 141); or placebo injections matching active treatment (n = 68). The co-primary efficacy endpoints were the proportion of patients achieving a Physician's Global Assessment (PGA) of 0/1 at week 12, and the proportion of patients achieving a Psoriasis Area and Severity Index (PASI) 75 response at week 12. RESULTS Of the briakinumab-treated patients, 71·0% achieved a PGA of 0/1 at week 12 as compared with 39·7% of etanercept-treated patients and 2·9% of placebo-treated patients, (P < 0·001, for both comparisons). Of the briakinumab-treated patients 81·9% achieved a PASI 75 response at week 12 as compared with 56·0% of etanercept-treated and 7·4% of placebo-treated patients (P < 0·001, for both comparisons). Serious adverse event rates were reported in four (2·9%) patients receiving briakinumab, one (0·7%) patient receiving etanercept and one (1·5%) placebo-treated patient. CONCLUSIONS In patients with moderate to severe psoriasis, briakinumab had superior efficacy to both placebo and etanercept at 12 weeks as administered in this study.
Collapse
|
55
|
Abstract
Objective: To develop comprehensive recommendations for the treatment of the various clinical manifestations of psoriatic arthritis (PsA) based on evidence obtained from a systematic review of the literature and from consensus opinion. Methods: Formal literature reviews of treatment for the most significant discrete clinical manifestations of PsA (skin and nails, peripheral arthritis, axial disease, dactylitis and enthesitis) were performed and published by members of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA). Treatment recommendations were drafted for each of the clinical manifestations by rheumatologists, dermatologists and PsA patients based on the literature reviews and consensus opinion. The level of agreement for the individual treatment recommendations among GRAPPA members was assessed with an online questionnaire. Results: Treatment recommendations were developed for peripheral arthritis, axial disease, psoriasis, nail disease, dactylitis and enthesitis in the setting of PsA. In rotal, 19 recommendations were drafted, and over 80% agreement was obtained on 16 of them. In addition, a grid that factors disease severity into each of the different disease manifestations was developed to help the clinician with treatment decisions for the individual patient from an evidenced-based perspective. Conclusions: Treatment recommendations for the cardinal physical manifestations of PsA were developed based on a literature review and consensus between rheumatologists and dermatologists. In addition, a grid was established to assist in therapeutic reasoning and decision making for individual patients. It is anticipated that periodic updates will take place using this framework as new data become available.
Collapse
|
56
|
An open-label, single-arm pilot study in patients with severe plaque-type psoriasis treated with an oral anti-inflammatory agent, apremilast. Curr Med Res Opin 2008; 24:1529-38. [PMID: 18419879 DOI: 10.1185/030079908x301866] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To evaluate the clinical and biological activity of apremilast in patients with severe plaque-type psoriasis. RESEARCH DESIGN AND METHODS Apremilast, a phosphodiesterase-4 inhibitor, inhibits in vitro activity of multiple inflammatory factors implicated in the pathogenesis of psoriasis. Patients received 20 mg apremilast orally for 29 days. Immunohistological analysis was conducted on lesional-skin biopsies for psoriasis-associated inflammatory markers. Lipopolysaccharide-stimulated tumor necrosis factor-alpha levels were evaluated in blood. Psoriasis Area and Severity Index (PASI), static Physician's Global Assessment, and Body Surface Area were used to monitor disease severity. RESULTS There were 19 patients enrolled in this study, of whom 17 completed the study. Epidermal thickness was reduced by a mean of 20.5% from baseline to day 29. Among the responders, T cells were reduced by 28.8% and 42.6% in the dermis and epidermis, respectively. Similarly, CD11c cells were reduced by 18.5% and 40.2% in the dermis and epidermis, respectively. Fourteen of the 19 (73.7%) patients demonstrated an improvement in their PASI scores. LIMITATIONS This was a small, single-arm, open-label pilot study; therefore there was neither a placebo nor a comparison group. CONCLUSION Apremilast demonstrated biological activity and improved psoriasis clinical efficacy scores in patients with severe plaque-type psoriasis. The majority of adverse events were mild in nature. Two adverse events (fatigue and dizziness) were judged by the investigator to be moderate and related to apremilast. In addition, there were no clinically-relevant abnormal laboratory test results in subjects treated with apremilast for 29 days.
Collapse
|
57
|
Abstract
Background Efalizumab, a T-cell-targeted, recombinant, humanized, monoclonal IgG1 antibody, inhibits key T-cell-mediated steps in the pathogenesis of psoriasis. Efalizumab is approved for the treatment of moderate-to-severe chronic plaque psoriasis in adults in more than 50 countries. Objectives To evaluate the efficacy and safety of long-term, continuous efalizumab therapy in patients with psoriasis. Methods This open-label, multicentre phase III study enrolled 339 patients with moderate-to-severe chronic plaque psoriasis. During the initial 3-month phase, patients received subcutaneous efalizumab 2 mg kg−1 weekly with randomization to receive concomitant fluocinolone acetonide or placebo ointment during month 3. The second phase was a long-term observational period; patients achieving a ≥ 50% improvement in the Psoriasis Area and Severity Index (PASI) score were eligible to receive efalizumab 1 mg kg−1 weekly for up to 33 months. The final 3-month treatment period was an optional transition period for patients who completed the 33-month segment before efalizumab became commercially available. Results After 3 months, 41·3% of patients achieved a ≥ 75% improvement in PASI (PASI-75) and 13·0% achieved a ≥ 90% improvement (PASI-90). Continued improvement was observed: 45·4% and 24·5% achieved PASI-75 and PASI-90, respectively, at the end of the observational phase. The safety profile was stable, with no new or no increase in common events over 36 months of treatment. Conclusions This was the longest continuous study using a biologic therapy for psoriasis. Clinical benefit of efalizumab improved over the first 18 months and was maintained during 36 months of continuous therapy. Long-term efalizumab therapy is appropriate for many patients with plaque psoriasis. Conflicts of interest C.L. with 3M Pharmaceuticals, Abbott, Allergan, Altana, Amgen, Astellas-Biogen, Bristol Myers, Centocor, CombinatoRx, Fujisawa Healthcare, Galderma, Genentech, Merck Serono International SA, Schering Plough, RTL, Vitae and Warner Chilcott; A.M. with 3M Pharmaceuticals, Abbott, Allergan, Allermed, Amgen, Astralis, Berlex, Biogen Idec, Celgene, Centocor, Cephalon, Collagenex Pharmaceuticals, CombinatoRx, Connetics, Corixa, Dermik Laboratories, Doak Dermatologics, Dow, Ferndale Laboratories, Fujisawa Healthcare, Galderma, Genentech, Genzyme, GlaxoSmithKline, Ligand Pharmaceuticals, Medicis, MedImmune, Novartis Pharmaceuticals, Otsuka Pharmaceutical, Protein Design Labs, QLT USA, Regeneration Pharma AG, Roche, Merck Serono International SA, Sinclair, Synta Pharma, Thermosurgery, Vertex, Warner Chilcott, Wyeth, XOMA and Zars; T.H. with Genentech; A.B.G. with Abbott, Actelion, Almirall, Amgen, Beiersdorf, Biogen Idec, Bristol Myers Squibb, Can-Fite, Celera, Celgene, Centocor, DermiPsor, Eisai, Genentech, Immune Control, Incyte, Kemia, Medacorp, Medarex, Novo Nordisk, Pharmacare, Roche, RxClinical, Sankyo, Schering Plough, TEVA, UCB, Warner Chilcott and Wyeth. All income derived from these sources goes to her employer. I.C. and B.X. are employees and stockholders of Genentech.
Collapse
|
58
|
Effects of etanercept therapy on fatigue and symptoms of depression in subjects treated for moderate to severe plaque psoriasis for up to 96 weeks. Br J Dermatol 2007; 157:1275-7. [PMID: 17916204 DOI: 10.1111/j.1365-2133.2007.08205.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
59
|
Comparison of clinical and pharmacokinetic profiles of etanercept 25 mg twice weekly and 50 mg once weekly in patients with psoriasis. Br J Dermatol 2006; 156:138-42. [PMID: 17199580 DOI: 10.1111/j.1365-2133.2006.07585.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Etanercept is a tumour necrosis factor antagonist that is approved in the U.S.A., Canada and Europe for treating adult patients with chronic moderate to severe plaque psoriasis. OBJECTIVES To assess whether clinical efficacy, safety and pharmacokinetic (PK) profiles of etanercept 50 mg once weekly are comparable to etanercept 25 mg twice weekly. METHODS Patients from a U.S. phase 3 study and a global phase 3 study were subsequently enrolled in an open-label extension study (extension study) where they all received etanercept at a dose of 50 mg once weekly for an initial 12 weeks. Patients who had received at least 24 weeks of etanercept 25 mg twice weekly in the global phase 3 study and were enrolled in the extension study (n = 265) were assessed for efficacy and safety at extension study baseline and after 12 weeks of etanercept 50 mg once weekly. Efficacy endpoints included the Psoriasis Area and Severity Index (PASI), the Dermatology Life Quality Index and the Physician's Global Assessment of psoriasis. In addition, PK profiles from patients in the U.S. phase 3 study were compared with PK profiles from another set of patients in the extension study. Comparison was made between a subset of patients receiving etanercept 25 mg twice weekly dosing in the U.S. phase 3 study (n = 13) and those receiving etanercept 50 mg once weekly in the extension study (n = 84). RESULTS The mean PASI score was 5.77 at extension study baseline after treatment with etanercept 25 mg twice weekly, which was sustained at 5.82 after 12 weeks of etanercept 50 mg once weekly. Similar results were observed in other efficacy endpoints. Etanercept 50 mg once weekly was generally well tolerated. No new safety findings were reported. PK profiles overlapped extensively between the two dosing regimens. CONCLUSIONS In this report, we demonstrate that efficacy, safety and PK profiles were comparable between etanercept 25 mg twice weekly and 50 mg once weekly in patients who had received at least 24 weeks of etanercept 25 mg twice weekly prior to receiving etanercept 50 mg once weekly in the extension study.
Collapse
|
60
|
Abstract
Alefacept is a bioengineered fusion protein of soluble lymphocyte function antigen (LFA-3) with Fc fragments of IgG1. It is marketed in many countries for the treatment of moderate to severe psoriasis. This paper reviews the data supporting the use of alefacept in psoriasis and psoriatic arthritis.
Collapse
|
61
|
Oral pimecrolimus in the treatment of moderate to severe chronic plaque-type psoriasis: a double-blind, multicentre, randomized, dose-finding trial. THE BRITISH JOURNAL OF DERMATOLOGY 2005. [PMID: 15948985 DOI: 10.1111/j.1365-2133.2005.06661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND There is a need for safe and effective alternative treatments for patients with moderate to severe psoriasis. OBJECTIVES Pimecrolimus is a calcineurin inhibitor that is being investigated in oral form for the treatment of psoriasis. PATIENTS AND METHODS A double-blind, randomized, parallel-group, dose-finding study was performed. Healthy adult outpatients with moderate to severe chronic plaque-type psoriasis (n = 143) were randomized to receive oral placebo or pimecrolimus 10 mg, 20 mg or 30 mg twice daily (b.d.) for 12 weeks. MAIN OUTCOME MEASURES The Psoriasis Area and Severity Index (PASI) was used to assess clinical severity of psoriasis. Results were analysed at weeks 7 (primary endpoint) and 13. Safety was assessed by monitoring all adverse events, laboratory investigations (blood chemistry, urinalysis, haematology) and physical examinations. RESULTS The change from baseline in PASI at week 7 showed a dose-dependent effect. The differences between each of the two higher doses of pimecrolimus and placebo were statistically significant (P < 0.001; ANOVA). The mean percentage decreases from baseline in PASI in the placebo group and pimecrolimus 10 mg, 20 mg and 30 mg b.d. groups at week 7 were 3.1%, 22.2%, 51.3% and 54.0%, respectively. Most adverse events were of mild or moderate severity. The only adverse event to show a dose-response relationship was a transient feeling of warmth. No clinically relevant effects on laboratory parameters were observed, and no increase in skin infection with pimecrolimus was seen. CONCLUSIONS Oral pimecrolimus produces a dose-dependent reduction in psoriasis severity, with doses of 20 mg and 30 mg b.d. being the most effective and well tolerated.
Collapse
|
62
|
Oral pimecrolimus in the treatment of moderate to severe chronic plaque-type psoriasis: a double-blind, multicentre, randomized, dose-finding trial. Br J Dermatol 2005; 152:1219-27. [PMID: 15948985 DOI: 10.1111/j.1365-2133.2005.06661.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND There is a need for safe and effective alternative treatments for patients with moderate to severe psoriasis. OBJECTIVES Pimecrolimus is a calcineurin inhibitor that is being investigated in oral form for the treatment of psoriasis. PATIENTS AND METHODS A double-blind, randomized, parallel-group, dose-finding study was performed. Healthy adult outpatients with moderate to severe chronic plaque-type psoriasis (n = 143) were randomized to receive oral placebo or pimecrolimus 10 mg, 20 mg or 30 mg twice daily (b.d.) for 12 weeks. MAIN OUTCOME MEASURES The Psoriasis Area and Severity Index (PASI) was used to assess clinical severity of psoriasis. Results were analysed at weeks 7 (primary endpoint) and 13. Safety was assessed by monitoring all adverse events, laboratory investigations (blood chemistry, urinalysis, haematology) and physical examinations. RESULTS The change from baseline in PASI at week 7 showed a dose-dependent effect. The differences between each of the two higher doses of pimecrolimus and placebo were statistically significant (P < 0.001; ANOVA). The mean percentage decreases from baseline in PASI in the placebo group and pimecrolimus 10 mg, 20 mg and 30 mg b.d. groups at week 7 were 3.1%, 22.2%, 51.3% and 54.0%, respectively. Most adverse events were of mild or moderate severity. The only adverse event to show a dose-response relationship was a transient feeling of warmth. No clinically relevant effects on laboratory parameters were observed, and no increase in skin infection with pimecrolimus was seen. CONCLUSIONS Oral pimecrolimus produces a dose-dependent reduction in psoriasis severity, with doses of 20 mg and 30 mg b.d. being the most effective and well tolerated.
Collapse
|
63
|
Infliximab treatment results in significant improvement in the quality of life of patients with severe psoriasis: a double-blind placebo-controlled trial. Br J Dermatol 2005; 152:954-60. [PMID: 15888152 DOI: 10.1111/j.1365-2133.2005.06510.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Psoriasis is a chronic disease that significantly diminishes the health-related quality of life (HRQOL). Infliximab is a chimeric, tumour necrosis factor alpha monoclonal antibody that has been shown to improve the signs and symptoms of plaque psoriasis. OBJECTIVES The objective of this study was to evaluate the effect of infliximab induction therapy on the HRQOL of patients with severe plaque psoriasis. METHODS In this double-blind, placebo-controlled trial, 249 patients were randomly assigned to receive intravenous infusions of 3 or 5 mg kg(-1) of infliximab or placebo and were treated at weeks 0, 2 and 6. Patients completed the Dermatology Life Quality Index (DLQI) at baseline and week 10. RESULTS Infliximab induction therapy resulted in a substantial improvement in HRQOL. At week 10, patients in the infliximab 3- and 5-mg kg(-1) groups showed a median percentage improvement in DLQI scores of 84.0% and 91.0%, respectively, compared with 0% in the placebo group (P < 0.001). The median decrease from baseline in DLQI score at week 10 was 8.0 and 10.0 for the 3 and 5 mg kg(-1) infliximab groups, respectively, compared with 0 in the placebo group (P < 0.001). Thirty-three per cent and 40% of patients in the 3 and 5 mg kg(-1) infliximab groups, respectively, had a DLQI score of 0 at week 10, compared with 2% in the placebo group (P < 0.001). There was a strong correlation between the percentage change from baseline at week 10 in Psoriasis Area and Severity Index (PASI) scores and the percentage change in DLQI scores during the same period (Spearman's correlation, 0.61, P < 0.001). When the infliximab and placebo treatment groups were combined, patients with at least 75% improvement in PASI scores between baseline and week 10 had a greater mean improvement in DLQI scores (81%) than those with 50-75% improvement in PASI during the same period (60%). CONCLUSIONS Infliximab induction therapy resulted in significant improvement in HRQOL in patients with severe psoriasis.
Collapse
|
64
|
Abstract
Accumulated data suggest that etanercept may be a therapeutic option in patients with hepatitis C and coexisting autoimmune disorders such as rheumatoid arthritis, psoriasis, psoriatic arthritis and ankylosing spondylitis. Additionally, etanercept may actually be of benefit, when used in combination with standard treatments, for hepatitis C.
Collapse
|
65
|
Clinical research helps elucidate the role of tumor necrosis factor-alpha in the pathogenesis of T1-mediated immune disorders: use of targeted immunotherapeutics as pathogenic probes. Lupus 2003; 12:190-4. [PMID: 12708779 DOI: 10.1191/0961203303lu354xx] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Psoriasis is a life-disabling disorder in which 8-10% of patients aged 18-54 actively contemplate suicide because of their disease. Owing to the toxicity and/or inconvenience of current, FDA-approved treatments far moderate-to-severe psoriasis, they are generally used intermittently so that patients experience cycles of remission-flare-remission-flare, etc. The challenge to drug development for moderate-to-severe psoriasis is to provide safe and effective long-term management. Immunobiologics offer the hope for safe, long-term control of psoriasis because they lack targeted organ toxicity. Thus the treatment paradigm may shift from one of intermittent treatment limited by toxicity with resultant flares of disease, to one similar to that seen in diabetes or hypertension in which disease is controlled continuously. Additionally, immunobiologics may alter the natural history of psoriasis. Etanercept, which targets TNF-alpha, controls signs and symptoms and halts joint destruction in patients with psoriatic arthritis. The long-lived remissions observed after cessation of alefacept or infliximab (anti-TNF-alpha monoclonal antibody) treatment lead this author to speculate that these immunobiologics may actually alter the natural history of the cutaneous manifestations of psoriasis.
Collapse
|
66
|
Antibody responses to bacteriophage X174 and tetanus toxoid are normal in patients receiving alefacept (human LFA-3/IgG1 fusion protein). J Allergy Clin Immunol 2002. [DOI: 10.1016/s0091-6749(02)81987-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
67
|
Abstract
Biologics in development for the treatment of moderate to severe plaque-type psoriasis are discussed in this article. Immunomodulators used as therapeutic, pathogenic probes will continue to identify targets that play primary roles in the pathogenesis of psoriasis.
Collapse
|
68
|
Consensus conference: acitretin in combination with UVB or PUVA in the treatment of psoriasis. J Am Acad Dermatol 2001; 45:544-53. [PMID: 11568745 DOI: 10.1067/mjd.2001.116347] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although adjunctive treatment with retinoids in concert with either psoralen-ultraviolet A (PUVA) or ultraviolet B (UVB) phototherapy has been a treatment option for chronic, moderate to severe plaque psoriasis for nearly two decades, acitretin-UV therapy is an underutilized therapeutic modality. According to a recent member survey by the National Psoriasis Foundation, many psoriasis patients are frustrated with available treatment options, which they perceive as ineffective, inconvenient, and/or excessively conservative. Treatment of psoriasis with acitretin in concert with UVB or PUVA is emerging as a viable clinical strategy. Compared with either acitretin or UV light monotherapy alone, the combination regimen enhances efficacy and limits treatment frequency, duration, and cumulative doses. These effects translate into care that is more effective, better tolerated, more convenient, less costly, and, perhaps, safer during long-term treatment than phototherapy alone. Drawing from an extensive literature search and the expertise of its participants, this consensus conference advances clinical recommendations as well as "clinical pearls" for health providers who treat patients with chronic, moderate to severe plaque psoriasis and suggests avenues for future research.
Collapse
|
69
|
Abstract
BACKGROUND Although betamethasone valerate (BMV) foam, 0.12% (Luxiq, Connectics Corporation, Palo Alto, CA) is approved by the Food and Drug Administration for the treatment of corticosteroid-responsive scalp dermatoses, no data are available for its use on nonscalp psoriasis. OBJECTIVE We evaluated the safety and efficacy of BMV foam in treating psoriatic lesions at nonscalp sites. METHODS We conducted a randomized, double-blind, placebo-controlled, paired-comparison, split-body study of 40 patients with mild to moderate plaque-type psoriasis. Patients applied BMV foam and placebo foam twice daily for 12 weeks. RESULTS At the end of the treatment period, 70% of patients had greater than 50% improvement of lesions on their active foam-treated side compared with 24% of patients with similar improvement on their placebo foam-treated side. Adverse effects were limited to temporary stinging, burning, or itching in several patients. Three patients (7.5%) withdrew because of stinging or itching. CONCLUSIONS The results indicate that BMV foam is effective against nonscalp psoriasis. Twice-daily applications are well tolerated, compliance exceeds 90%, cosmetic characteristics are acceptable, and the medication may reduce the need for multiple prescriptions.
Collapse
|
70
|
Abstract
BACKGROUND Currently available treatments for moderate to severe psoriasis are either incompletely effective in some patients, or are associated with toxic effects. Since tumour necrosis factor alpha (TNF-alpha) is thought to have a role in the pathogenesis of psoriasis, we did a double-blind, randomised trial to assess the clinical benefit and safety of infliximab-a monoclonal antibody against TNF-alpha. METHODS 33 patients with moderate to severe plaque psoriasis were randomly assigned intravenous placebo (n=11), infliximab 5 mg/kg (n=11), or infliximab 10 mg/kg (n=11) at weeks 0, 2, and 6. Patients were assessed at week 10 for the primary endpoint (score on the physician's global assessment [PGA]). Analysis was by intention to treat. FINDINGS Of the 33 patients enrolled, three dropped out. Nine of 11 (82%) patients in the infliximab 5 mg/kg group were responders (good, excellent, or clear rating on PGA), compared with two of 11 (18%) in the placebo group (difference 64% [95% CI 20-89], p=0.0089), and ten of 11 (91%) patients in the infliximab 10 mg/kg group were responders (difference from placebo 73% [30-94], p=0.0019). The median time to response was 4 weeks for patients in both infliximab groups. There were no serious adverse events, and infliximab was well tolerated. INTERPRETATION In this controlled trial, patients receiving the anti-TNF-alpha agent infliximab as monotherapy experienced a high degree of clinical benefit and rapid time to response in the treatment of moderate to severe plaque psoriasis compared with patients who received placebo. These findings suggest that TNF-alpha has a pivotal role in the pathogenesis of psoriasis.
Collapse
|
71
|
Concomitant administration of vitamin E does not change the side effects of isotretinoin as used in acne vulgaris: a randomized trial. J Am Acad Dermatol 2000; 43:777-84. [PMID: 11050580 DOI: 10.1067/mjd.2000.110391] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Isotretinoin treatment is frequently associated with reversible, dose-related side effects. Recent studies claimed that combining vitamin E with high-dose isotretinoin ameliorated isotretinoin-induced side effects. OBJECTIVE The purpose of this double-blind, randomized study was to determine the effects of a fixed dose of vitamin E on the side effects of isotretinoin for treatment-resistant acne vulgaris. METHODS One hundred forty subjects were randomly assigned to one of two treatment programs with isotretinoin (1 mg/kg) together with either vitamin E (800 IU/day) or a vitamin E placebo for 20 weeks. The incidence, severity, and duration of the side effects (eg, dry eyes, dry lips) were assessed. RESULTS A fixed 800 IU/day dose of vitamin E did not improve the incidence, severity, or duration of side effects associated with isotretinoin (1 mg/kg per day). CONCLUSION Vitamin E did not significantly ameliorate retinoid side effects when combined with 1 mg/kg of isotretinoin in the treatment of acne.
Collapse
|
72
|
Anti-CD4 monoclonal antibody treatment of moderate to severe psoriasis vulgaris: results of a pilot, multicenter, multiple-dose, placebo-controlled study. J Am Acad Dermatol 2000; 43:595-604. [PMID: 11004613 DOI: 10.1067/mjd.2000.107945] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND OKTcdr4a (IMUCLONE) is a humanized anti-CD4 IgG4 monoclonal antibody that retains the binding and in vitro immunosuppressive properties of the parent murine antibody. Psoriasis is a chronic disease for which treatment with multiple doses of monoclonal antibodies is likely to be required for adequate control. OBJECTIVE This study was performed to test the efficacy and safety of OKTcdr4a, given in sequential courses over a period of several weeks, in the treatment of moderate to severe psoriasis vulgaris. METHODS Twenty-eight patients (45.6 +/- 10.1 years of age) were studied, with a mean pretreatment Psoriasis Area and Severity Index (PASI) score of 18.3. In the first double-blind phase of the study, patients were randomized to receive OKTcdr4a as a 225 mg/course (low dose), 750 mg/course (high dose), or placebo divided into 3 identical infusions over a 5-day period. After 42 days, patients who met the criteria for re-treatment with OKTcdr4a were re-treated with the 750 mg/course in an open phase of the study. RESULTS After the double-blind course of treatment, the mean PASI decreased by 11% in the placebo group, by 4% in the low-dose group, and by 17% in the high-dose group at 15 days. Twenty patients met the criteria for re-treatment (ie, did not experience a decrease in PASI score of 50% at 42 days). They were re-treated with OKTcdr4a at 43 days with the 750 mg/course in the open phase of the study. By day 99, the mean PASI score decreased from 19.9 at baseline to 17 in those patients who had received either placebo or low-dose OKTcdr4a followed by high-dose OKTcdr4a. In contrast, the mean PASI score decreased from 17.4 at baseline to only 7.7 in those patients who had received high-dose OKTcdr4a for both courses. Sustained CD4 saturation was not necessary for sustained clinical response. No patients had significant changes in circulating CD4(+) T-cell counts. The infusions were well tolerated. CONCLUSION Targeting CD4 using sequential treatments with a humanized monoclonal antibody (OKTcdr4a) may offer another therapeutic option for the treatment of moderate to severe psoriasis.
Collapse
|
73
|
Successful in vivo blockade of CD25 (high-affinity interleukin 2 receptor) on T cells by administration of humanized anti-Tac antibody to patients with psoriasis. J Am Acad Dermatol 2000; 43:448-58. [PMID: 10954656 DOI: 10.1067/mjd.2000.106515] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Daclizumab is a humanized antibody to the alpha-subunit (CD25) of the interleukin 2 (IL-2) receptor that blocks normal IL-2 binding to this receptor. Because IL-2 is a major stimulus for T-cell growth, blockade of the IL-2 receptor could be useful in treating T-cell-mediated (autoimmune) diseases. OBJECTIVE Our purpose was to determine whether adequate concentrations of antibody were achieved in circulating blood and in psoriatic skin lesions to saturate CD25 receptors. We also intended to measure clinical effect and safety of this agent when used alone (without other immunosuppressive drugs) in psoriasis. METHODS Nineteen patients with psoriasis in two centers received daclizumab at an initial dose of 2 mg/kg, then 1 mg/kg at weeks 2, 4, 8, and 12. To determine whether CD25 was blocked in vivo, flow cytometric studies measured (1) expression of CD25 on CD3(+) T cells derived from blood and (2) immuno-histochemistry measures of CD25(+) cells done on pretreatment and posttreatment biopsy specimens. Patients were followed up clinically with photographs and Psoriasis Area and Severity Index scores. RESULTS This study showed a consistent blockade of CD25 in peripheral blood and tissue during the first 4 weeks of therapy while the dosing was every 2 weeks. Variable desaturation of receptors began after 4 weeks, which correlated with a reversal in disease improvement. Patients with a pretreatment Psoriasis Area and Severity Index score of less than 36 showed a mean reduction in severity by 30% at 8 weeks (P =.02). During the 16 weeks of treatment, a 44.8% decrease in expression of the IL-2 receptor alpha-subunit was found. The absolute T-cell counts were calculated and showed no significant changes during the course of the study. No significant adverse events were produced by daclizumab during this study. CONCLUSION We therefore conclude that daclizumab is a well-tolerated agent that blocks CD25 expression in peripheral blood and skin. Furthermore, it may be useful in treating psoriasis in some patients.
Collapse
|
74
|
Two considerations for patients with psoriasis and their clinicians: what defines mild, moderate, and severe psoriasis? What constitutes a clinically significant improvement when treating psoriasis? J Am Acad Dermatol 2000; 43:281-5. [PMID: 10906652 DOI: 10.1067/mjd.2000.106374] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The definitions of psoriasis severity and clinically significant improvement in psoriasis are used to classify treatments, obtain Food and Drug Administration approval, and determine product labeling and reimbursement. The Medical Advisory Board of the National Psoriasis Foundation has addressed these issues because of their importance in the clinical trials that are conducted to gain FDA approval of indications. Narrow indications, which are without a sound rational basis, will-in this era of constant oversight by third party payers-affect physicians' ability to manage patients with psoriasis. Body surface area (BSA) is usually used to define severity for clinical trials. It is not optimal for defining psoriasis severity because there are some patients with low BSA involvement who have very severe psoriasis and some patients with high BSA involvement who have mild psoriasis. We conclude that a quality of life (QOL) standard is better than BSA measurement for identifying patients with severe psoriasis. The second issue is what defines clinically significant improvement for patients with psoriasis. Setting an arbitrarily high criterion of clinical efficacy for new psoriasis treatments will likely limit the development and approval of useful treatments. To maximize the availability of useful psoriasis treatments, it is our thesis that psoriasis treatments should be approved when they have been shown to produce a statistically significant level of improvement in well-designed clinical trials.
Collapse
|
75
|
Treatment with anti-tumor necrosis factor alpha (TNF-alpha) monoclonal antibody dramatically decreases the clinical activity of psoriasis lesions. J Am Acad Dermatol 2000; 42:829-30. [PMID: 10775863 DOI: 10.1067/mjd.2000.105948] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We treated a 57-year-old woman for refractory inflammatory bowel disease with a humanized anti-tumor necrosis factor alpha monoclonal antibody (Infliximab). The patient also had a 15-year history of Crohn's disease and a 20-year history of moderate to severe psoriasis. She received a single infusion of Infliximab (5 mg/kg). Two weeks after the infusion her psoriasis had dramatically improved in appearance. To our knowledge, our case is the first reported instance of successful anti-tumor necrosis factor alpha therapy in psoriasis.
Collapse
|
76
|
Staphylococcal scalded skin syndrome in an immunocompetent adult: possible implication of low-dosage prednisone. Cutis 1998; 62:223-4. [PMID: 9836053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Staphylococcal scalded skin syndrome (SSSS) mainly affects infants and young children. Very few cases of adult SSSS have been reported. Adult SSSS is usually associated with immunosuppression, overwhelming sepsis, and kidney failure. We report the case of an immunocompetent 51-year-old woman without renal failure who sustained SSSS after a 7-day course of oral prednisone administered postoperatively.
Collapse
|
77
|
|
78
|
Intravenous cyclosporine therapy in the treatment of pyoderma gangrenosum secondary to Crohn's disease. Cutis 1997; 60:135-8. [PMID: 9314617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pyoderma gangrenosum is a destructive, ulcerative skin condition often associated with systemic illnesses such as inflammatory bowel disease, myeloproliferative disorders, and the inflammatory arthritides. We present a patient with long-standing pyoderma gangrenosum associated with Crohn's disease. Multiple deep leg ulcerations were unresponsive over the course of several years to treatment with azathioprine, systemic corticosteroids, 6-mercaptopurine, and dapsone. The patient was hospitalized and treated with a ten-day course of intravenous cyclosporine therapy followed by outpatient oral cyclosporine and showed significant improvement.
Collapse
|
79
|
Immunopathogenesis of psoriasis. The road from bench to bedside is a 2-way street. ARCHIVES OF DERMATOLOGY 1997; 133:781-2. [PMID: 9197838 DOI: 10.1001/archderm.133.6.781] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
80
|
Identification of aberrantly regulated genes in diseased skin using the cDNA differential display technique. J Invest Dermatol 1997; 108:188-94. [PMID: 9008232 DOI: 10.1111/1523-1747.ep12334217] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
It is hypothesized that psoriasis may be caused by aberrant gene expression. In an effort to identify and clone psoriasis-specific genes, we compared gene expression in normal, tape-stripped (wounded), and psoriatic skin using the cDNA differential display technique. Four genes not previously described in psoriasis--connexin 26, a gap junction protein; squamous cell carcinoma antigen-1 (SCCA1), a serine protease inhibitor; and mitochondrial NAD subunits 5 and 6--were identified as having very high expression levels in psoriatic skin. In situ hybridizations showed that connexin 26 mRNA was expressed 10-fold higher in psoriatic and 4-fold higher in tape-stripped epidermis than in controls. SCCA1 showed a 40-fold increase in mRNA expression, whereas mitochondrial NAD5 and NAD6 expression was increased 10- and 20-fold, respectively, in psoriatic skin. Northern blots confirmed the increased expression of connexin 26, SCCA1, and NAD6 genes in psoriatic skin. Immunohistochemistry showed that connexin 26 protein was strongly expressed in spinous keratinocytes from psoriatic skin and chronic wounds, but was absent in normal epidermis. These studies demonstrate the usefulness of this approach for identifying genes that are conditionally expressed in growth-activated human skin.
Collapse
|
81
|
Cellular actions of etretinate in psoriasis: enhanced epidermal differentiation and reduced cell-mediated inflammation are unexpected outcomes. J Cutan Pathol 1996; 23:404-18. [PMID: 8915849 DOI: 10.1111/j.1600-0560.1996.tb01430.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Retinoids are potent cell growth and differentiation modulators, but cellular effects of therapeutic retinoids in psoriasis are unknown. We studied the effects of etretinate on pathological activation of keratinocytes and lymphocytes in patients treated systemically with this agent for 8 weeks. Ten patients with extensive psoriasis vulgaris were treated with etretinate at 0.75 mg/kg for 8 weeks. Skin biopsies obtained before and at 8 weeks of treatment were studied using immunohistochemical markers for keratinocyte proliferation or differentiation and for the presence of T-lymphocyte subsets or associated inflammatory proteins. During 8 weeks of treatment, the clinical severity decreased by a mean of 64% (p < 0.001). Compared to a similar group of patients treated with bath PUVA, psoriatic plaque erythema resolved more slowly and less completely (p < 0.05), but improvements in plaque thickness and scale were not significantly different between etretinate and PUVA treatments. Etretinate produced a 44% decrease in epidermal thickness (p < 0.001) and a 62% reduction in keratinocyte proliferation (p < 0.001) after 8 weeks of treatment. Unexpectedly, keratinocyte differentiation was enhanced following etretinate treatment as indicated by increased filaggrin production, increased number and size of keratohyaline granules, greater abundance of keratin filaments, and increased secretion of intercellular lipids from Odland bodies. The stratum corneum in resolving psoriatic lesions was unusually thin, probably caused by retinoid-induced shedding of corneocytes. "Regenerative" epidermal growth was maintained during etretinate treatment, as marked by continued expression of keratin 16 and alpha 3-integrin by suprabasal keratinocytes. Surprisingly the inflammation-associated proteins HLA-DR and ICAM-1 were no longer produced by epidermal keratinocytes following etretinate treatment, and CD3+, CD8+, and CD25+ T-lymphocyte subsets were reduced by 50-65% in lesional tissue (p < 0.01). Etretinate shows unexpected anti-inflammatory and pro-differentiation actions in psoriasis. Etretinate appears to function as a disease suppressive agent which improves hyperplasia, keratinocyte differentiation and tissue inflammation mediated by cellular immune elements.
Collapse
|
82
|
Modulation of epidermal differentiation, tissue inflammation, and T-lymphocyte infilitration in psoriatic plaques by topical calcitriol. J Cutan Pathol 1996; 23:419-30. [PMID: 8915850 DOI: 10.1111/j.1600-0560.1996.tb01431.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Psoriasis is characterized by immune activation, increased proliferation and abnormal differentiation of keratinocytes. The reported anti-psoriatic mechanisms of action in vivo of vitamin D analogues include reduction of keratinocyte proliferation and induction of keratinocyte terminal differentiation. We investigated whether the anti-psoriatic effect of the natural active vatamin D analogue, calcitriol, applied topically, is due to direct effects on keratinocytes alone or also due to immunoregulatory effects of calcitriol. Psoriasis patients were treated with topical calcitriol (0.005%) and a vehicle control for 8 weeks. Disease activity was assessed by a severity index and quantitative histopathological markers. In vitro studies of lymphocyte proliferation and gamma interferon secretion and of keratinocyte proliferation complemented the clinicohistopathologic studies. A heterogeneous response to calcitriol treatment could be segregated based upon elimination of K-16 keratin expression. Calcitriol treatment decreased keratinocyte proliferation, normalized keratinocyte differentiation and decreased immune activation in plaques. The histologic response to vitamin D treatment of psoriasis includes suppression of both immune and keratinocyte activation in situ. These studies provide a basis for rational combination of anti-psoriatic treatments and for the design of new vitamin D analogues to treat psoriasis.
Collapse
|
83
|
The insulin-like growth factor 1 receptor is expressed by epithelial cells with proliferative potential in human epidermis and skin appendages: correlation of increased expression with epidermal hyperplasia. J Invest Dermatol 1996; 106:564-70. [PMID: 8648195 DOI: 10.1111/1523-1747.ep12344044] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Ligand-mediated activation of the insulin-like growth factor 1 (IGF-1) receptor is critical for epidermal keratinocyte proliferation in vitro, and its expression in normal and psoriatic epidermis suggests that it might regulate keratinocyte proliferation in vivo. In this study, we used a monoclonal antibody (alpha-IR3) that binds to the alpha-chain of this receptor to study its expression (i) in other epithelial cell types in human skin and (ii) in growth-activated epidermis associated with various cutaneous pathologies. In normal skin, IGF-1 receptors were expressed by basal epidermal keratinocytes as well as by basal-like or undifferentiated germinative epithelial cells associated with the follicular outer root sheath, sebaceous glands, and the hair matrix. There was minimal IGF-1 receptor expression in differentiating outer root sheath, hair shaft, and sebaceous epithelial cells. IGF-1 receptor expression in non-growth-activated epidermis of long-standing seborrheic keratoses was confined to the basal epidermal layer, as in normal epidermis. In contrast, hyperplastic epidermis undergoing "regenerative" differentiation (keratin 16+, Ki67+ suprabasal keratinocytes) from psoriasis, chronic skin wounds, and plaques of mycosis fungoides consistently showed increased expression of IGF-1 receptor. In these conditions, the region of expanded IGF-1 receptor expression delimited the epidermal zone of keratinocyte proliferation. In cultured keratinocytes, the subcellular localization of the IGF-1 receptor could be modulated from plasma membranes to the cell cytoplasm by ligand binding, suggesting that the in vivo cytoplasmic staining occasionally observed represents internalization of receptors following ligand stimulation. Our results suggest that cell surface IGF-1 receptors are widely expressed by epithelial cells with proliferative potential, that receptor expression can be modulated with differing epidermal growth states, and that these receptors are largely downregulated in highly differentiated epithelial cells.
Collapse
|
84
|
Abstract
Growth of normal melanocytes, nevus cells and primary melanoma cells is enhanced by insulin/insulin-like growth factor-I (IGF-I) in vitro. It has been shown that a melanoma cell line possesses the IGF-I receptor which plays a role in activation of the chemotactic response. Little is known about the in vivo expression of the IGF-I receptor and its role in melanocytic lesions. In an immunohistochemical study, we investigated the expression of IGF-I receptor in frozen sections of congenital pigmented nevi from 10 patients (ages 8 months to 4 yrs) using the monoclonal antibody alpha IR3, which specifically recognizes the extracellular alpha subunit of the IGF-I receptor. The proliferative activity of the nevus cells was examined by staining with Ki67 monoclonal antibody (reactive with all actively cycling cells). IGF-I receptor was found to be widely expressed by the cell surface of the nevus cells. Membrane staining was occasionally stronger in the superficial portion of the congenital pigmented nevi. In contrast, Ki67-positive cells were only sparsely scattered throughout the nevi with some tendency to localization to the superficial portion. This study indicates that in vivo the IGF-I receptor is widely expressed by congenital pigmented nevus cells. As opposed to keratinocytes, in which IGF-I receptor expression defines the proliferation pool of the normal and disordered epidermis, the IGF-I receptor is expressed by all nevus cells, irrespective of their proliferative status. Further studies are needed to assess whether the IGF-I receptor expression can serve as a marker for increased risk for development of malignancy in various types of benign melanocytic lesions.
Collapse
|
85
|
Pharmacokinetics and pharmacodynamics of AC137 (25,28,29 tripro-amylin, human) after intravenous bolus and infusion doses in patients with insulin-dependent diabetes. J Clin Pharmacol 1996; 36:13-24. [PMID: 8932539 DOI: 10.1002/j.1552-4604.1996.tb04147.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A study was conducted to evaluate the effect of 30-mug, 100-mug, and 300-mug 2-minute bolus doses and 2-hour infusion doses of AC137 (25,28,29 tripro-amylin, human) on plasma AC137 concentrations and plasma glucose and lactate responses in patients with insulin-dependent diabetes mellitus (IDDM). The study design was an imbedded two-way cross-over wherein patients received placebo and active boluses in one period and placebo and active infusions in the other period. Two patients in each dose group received placebo throughout the two periods. Pharmacokinetics and pharmacodynamics (PK/PD) were determined during the 6-hour period after initiation of dosing. Data were fitted with a linked PK/PD model. Pharmacokinetics were linear over the dose range studied, and attenuation of glucose and lactate responses to a mixed meal was dose and concentration dependent. The results of the PK/PD model indicate that the attenuation of glucose and lactate responses was greater after AC137 infusion doses than after the same doses given as a bolus. Glucose and lactate responses to a mixed meal were essentially negated by the 300-mug infusion dose.
Collapse
|
86
|
Successful ultraviolet B treatment of psoriasis is accompanied by a reversal of keratinocyte pathology and by selective depletion of intraepidermal T cells. J Exp Med 1995; 182:2057-68. [PMID: 7500051 PMCID: PMC2192269 DOI: 10.1084/jem.182.6.2057] [Citation(s) in RCA: 169] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Skin irradiation with ultraviolet B (UVB) is a common and often durable treatment for psoriasis and other inflammatory skin disorders. We studied the effects of UVB on keratinocytes and leukocytes in psoriatic tissue and in culture. In nine patients treated repetitively, most of the cellular and molecular changes that typify the psoriatic epidermis reverted to normal. Keratinocyte hyperplasia, assessed by expression of the Ki-67 cell cycle antigen, decreased by 70%, and residual cell proliferation was appropriately confined to the basal layer. Epidermal thickening was reduced by 60%, and a granular layer reformed. Expression of keratin 16, as well as suprabasal integrin alpha 3 and insulin-like growth factor-1 receptors, was eliminated, whereas filagrin increased markedly. UVB also depleted > 90% of the CD3+, CD8+, and CD25+ T cells from the psoriatic epidermis, whereas dermal T cells were only minimally depressed. The latter finding parallels the known inability of these doses of UVB to penetrate the dermis. In tissue culture, UVB was antiproliferative and cytotoxic toward T cells and keratinocytes, but the T cells were 10-fold more sensitive. Furthermore, low doses of UVB induced apoptosis in lymphocytes but not keratinocytes, as detected by the TUNEL (TdT-mediated dUTP-biotin nick end labeling) technique. The selective effects of UVB on intraepidermal T cells in situ and in culture support the hypothesis that epidermal alterations in psoriasis can be normalized by a depletion of activated intraepidermal T cells.
Collapse
|
87
|
Short-contact anthralin treatment augments therapeutic efficacy of cyclosporine in psoriasis: a clinical and pathologic study. J Am Acad Dermatol 1995; 33:637-45. [PMID: 7545705 DOI: 10.1016/0190-9622(95)91286-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Psoriasis is characterized by immune activation and increased epidermal proliferation. Cyclosporine acts by reducing T lymphocyte numbers and lymphokine production. Anthralin inhibits keratinocyte proliferation. OBJECTIVE We investigated whether topical anthralin would augment clearing of psoriasis produced by systemic cyclosporine. METHODS Twelve patients with psoriasis were treated with cyclosporine (5 mg/kg per day). Patients applied anthralin only to plaques on half of their body. They were treated until a remission or maximum benefit was achieved. Disease activity was assessed by a severity index and quantitative histopathologic markers. RESULTS Of the 12 patients, the skin of five cleared within 10 weeks irrespective of anthralin use. The other seven (slow responders) continued treatment for a mean of 18 weeks. Slow responders had a significantly lower severity index, a thinner epidermis, fewer CD8+ cells, and fewer proliferating keratinocytes on the anthralin-treated side than on the non-anthralin-treated side. CONCLUSION The combination of cyclosporine and topical anthralin is effective in patients who are slow to respond to cyclosporine alone.
Collapse
|
88
|
Response of psoriasis to a lymphocyte-selective toxin (DAB389IL-2) suggests a primary immune, but not keratinocyte, pathogenic basis. Nat Med 1995; 1:442-7. [PMID: 7585092 DOI: 10.1038/nm0595-442] [Citation(s) in RCA: 413] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Psoriasis is a hyperproliferative and inflammatory skin disorder of unknown aetiology. A fusion protein composed of human interleukin-2 and fragments of diphtheria toxin (DAB389IL-2), which selectively blocks the growth of activated lymphocytes but not keratinocytes, was administered systemically to ten patients to gauge the contribution of activated T cells to the disease. Four patients showed striking clinical improvement and four moderate improvement, after two cycle of low dose IL-2-toxin. The reversal of several molecular markers of epidermal dysfunction was associated with a marked reduction in intraepidermal CD3+ and CD8+ T cells, suggesting a primary immunological basis for this widespread disorder.
Collapse
|
89
|
GM-CSF activates regenerative epidermal growth and stimulates keratinocyte proliferation in human skin in vivo. J Invest Dermatol 1994; 103:601-4. [PMID: 7930689 DOI: 10.1111/1523-1747.ep12396936] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Granulocyte/macrophage-colony-stimulating factor (GM-CSF), an immunomodulator of hematopoietic cells, has also been shown to stimulate human keratinocyte proliferation in vitro and speed healing of wounds in the skin of lepromatous leprosy patients. In this study we have examined the in vivo effects of recombinant human GM-CSF on epidermal keratinocyte proliferation and on expression of proteins marking regenerative epidermal growth. Skin biopsies from GM-CSF injected cutaneous sites were obtained between 1 and 6 d following administration of 7.5 or 15 micrograms of the growth factor. Activation of keratinocyte proliferation, quantified as the expression of the Ki67+ nuclear antigen, was noted 1 d following GM-CSF administration. A regenerative epidermal phenotype, demonstrated by immunohistochemical staining of cellular proteins involucrin, filaggrin, and keratin 16, was similarly noted as early as 1 d following GM-CSF injection. This phenotype persisted as late as 6 d post-injection. These results suggest that GM-CSF injection into human skin induces keratinocyte proliferation as well as regenerative differentiation of the epidermis. To date no other cytokine has been shown to be mitogenic for human keratinocytes both in vivo and in vitro or to alter keratinocyte differentiation along the "alternate" or regenerative pathway.
Collapse
|
90
|
PUVA bath therapy strongly suppresses immunological and epidermal activation in psoriasis: a possible cellular basis for remittive therapy. J Exp Med 1994; 180:283-96. [PMID: 7516410 PMCID: PMC2191572 DOI: 10.1084/jem.180.1.283] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Psoriasis is characterized by alterations in both the epidermis and dermis of the skin. Epidermal keratinocytes display marked proliferative activation and differentiate along an "alternate" or "regenerative" pathway, while the dermis becomes infiltrated with leukocytes, particularly interleukin 2 (IL-2) receptor-bearing "activated" T cells. Psoralens, administered by the oral route, have therapeutic effects in psoriasis when photochemically activated by ultraviolet A light (PUVA therapy). Recently psoralen bath therapy has been introduced to more effectively deliver this agent to the diseased skin. We have correlated the efficacy of PUVA bath therapy with its effects on specific molecular and cellular parameters of disease, in 10 consecutive patients with recalcitrant psoriasis. Rapid clearing of lesions occurred in 8 out of 10 patients. Biopsies were taken from lesional and nonlesional skin before and after a single round of therapy, and observation was continued in our Clinical Research Center at The Rockefeller University. Enumeration of cycling keratinocytes with the Ki-67 monoclonal antibody showed that PUVA reduced cell proliferation by 73%. The pathological increase in insulin-like growth factor 1 (IGF-1) receptors was reversed, whereas epidermal growth factor (EGF) receptors, which are also increased in psoriasis, remained unchanged. Keratinocyte proteins that are expressed in abnormal sites of the epidermis during psoriasis, i.e., keratin 16, filaggrin, and involucrin, were, after PUVA treatment, localized to their normal sites. Epidermal and dermal T-lymphocytes (CD3+), as well as CD4+, CD8+, and IL-2 receptor+ subsets, were strongly suppressed by PUVA, with virtual elimination of IL-2 receptor+ T cells in some patients. Consistent with diminished lymphocyte activation, HLA-DR expression by epidermal keratinocytes was markedly reduced in treated skin. In comparison to cyclosporine treatment of psoriasis, PUVA therapy leads to more complete reversal of pathological epidermal and lymphocytic activation, changes which we propose to be the cellular basis for a more sustained remission of disease after PUVA treatment.
Collapse
|
91
|
|
92
|
Abstract
Anthralin is an effective topical treatment for active psoriasis; however, its mechanism of action is unknown. Both TGF-alpha and its receptor, the EGF receptor, are overexpressed in active psoriatic plaques and might, therefore, play a role in psoriatic epidermal hyperplasia. In order to assess whether anthralin might act via alteration of this growth factor pathway, we examined the in vitro effects of pharmacologic concentrations of anthralin on cultured normal human keratinocytes. Keratinocyte proliferation was inhibited by 98% at an anthralin concentration of 10 ng/ml. In contrast, lymphocyte proliferation was inhibited by only 50% at an anthralin concentration of 10 micrograms/ml. Anthralin treatment did not induce cell-cycle-specific growth arrest as assessed by flow-cytometric analysis of acridine-orange-stained keratinocytes. Northern analysis of anthralin-treated keratinocytes demonstrated a marked decrease in TGF-alpha mRNA expression. Anthralin-treated keratinocytes showed decreased binding of 125I-EGF and 125I-IGF-I to their respective receptors, but EGF receptor binding was inhibited to a greater extent. Anthralin decreased ligand-binding affinity and cell-surface numbers of EGF receptors as assessed by Scatchard analysis of 125I-EGF binding to anthralin-treated keratinocytes. These results indicate that anthralin alters components of the EGF receptor pathway in cultured keratinocytes and that these effects might contribute to the clinical efficacy of anthralin in the treatment of active psoriasis.
Collapse
|
93
|
The insulin-like growth factor I receptor is overexpressed in psoriatic epidermis, but is differentially regulated from the epidermal growth factor receptor. J Exp Med 1992; 175:1081-90. [PMID: 1313074 PMCID: PMC2119176 DOI: 10.1084/jem.175.4.1081] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Insulin-like growth factor I (IGF-I)/somatomedin C is an important mediator of keratinocyte growth in vitro, and the expression of IGF-I receptors in the basal layer of normal epidermis suggests that this growth pathway may function in the regulation of keratinocyte growth in vivo as well. The pattern of IGF-I receptor expression in normal skin is distinct from that of the epidermal growth factor (EGF) receptor, suggesting that these receptors might be differentially regulated. The purpose of this study was to obtain a better understanding of IGF-I receptor function in the skin by examining IGF-I receptor expression in psoriatic epidermis and in cultured human keratinocytes. Our findings indicate that IGF-I receptor expression is increased in psoriasis as measured by protein tyrosine kinase assays of biopsy extracts and by immunohistochemical staining with an IGF-I receptor-specific monoclonal antibody. Unlike EGF receptor expression, which is also increased in psoriatic epidermis, the pattern of IGF-I receptor expression corresponds closely with the increased size of the keratinocyte proliferative compartment in psoriasis. Biochemical agents that diminish EGF receptor ligand binding (phorbol ester or calcium ionophore treatment) produce opposite effects on the IGF-I receptor. These results suggest that cellular expression and differential regulation of both growth factor receptor systems may control critical aspects of epidermal proliferation or function.
Collapse
|
94
|
Studies of the Effect of Cyclosporine in Psoriasis In Vivo: Combined Effects on Activated T Lymphocytes and Epidermal Regenerative Maturation. J Invest Dermatol 1992; 98:302-9. [PMID: 1372027 DOI: 10.1111/1523-1747.ep12499782] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cyclosporine (CSA) decreases lymphokine synthesis and keratinocyte proliferation in vitro, but its in vivo mechanism of action in treating recalcitrant psoriasis is incompletely understood. Ten psoriasis patients were treated with CSA (2-7.5 mg/kg/d) with clinical improvement in nine of 10 patients. Skin biopsies before and after 1-3 months of CSA treatment were studied for evidence of immune and keratinocyte activation using immunoperoxidase and Northern blotting analysis. The number of activated, IL-2 receptor+ T cells in plaques after CSA treatment was reduced in all patients by a mean of 60%. Seven of 10 patients showed a decrease in keratinocyte HLA-DR expression; five of seven showed a decrease in gamma-IP-10 immunoreactivity, suggesting a decline in gamma interferon levels in plaques after CSA therapy. We studied the effect of CSA treatment in vivo on TGF-alpha, IL-6, and keratin K16 expression, three markers of keratinocyte growth activation. Expression of keratinocyte TGF-alpha and IL-6, which are elevated in active psoriatic epidermis, did not change in these patients after CSA treatment. The majority of patients (five of eight) continued to express the hyperproliferative keratin K16 after CSA treatment. Our results suggest that the predominant direct mechanism of action of Cyclosporine in vivo is a diminution of T-cell activation in plaques, with attendant decreased lymphokine production.
Collapse
|
95
|
|
96
|
Abstract
Eight patients received cyclosporine at doses of 2.0 to 7.5 mg/kg/day. Seven of these patients had increased fasting plasma triglyceride levels with cyclosporine therapy compared with pretreatment values, which peaked after 1 month of therapy. Four patients experienced elevations in fasting triglycerides, over the upper limits for age- and sex-matched controls, which were at least two times higher than their baseline values. It was striking that all four of these patients had previously had hypertriglyceridemia while using etretinate and three of these patients had preexisting hypertriglyceridemia before both etretinate and cyclosporine therapy. Triglyceride elevation did not correlate with cyclosporine levels. Thus cyclosporine, similar to etretinate, unmasks a latent tendency for mild to moderate hypertriglyceridemia. Fasting triglyceride levels should be monitored during cyclosporine therapy, especially after 1 to 2 months of use, and in patients with preexisting increased triglycerides and/or a history of etretinate use.
Collapse
|
97
|
Cyclosporine in psoriasis treatment. Inhibition of keratinocyte cell-cycle progression in G1 independent of effects on transforming growth factor alpha/epidermal growth factor receptor pathways. ARCHIVES OF DERMATOLOGY 1991; 127:1172-9. [PMID: 1677800 DOI: 10.1001/archderm.127.8.1172] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyclosporine, an immunosuppressive drug, is effective in the treatment of recalcitrant psoriasis. Previous work suggested that keratinocyte hyperproliferation and inflammation are linked in psoriasis and that immune mechanisms participate in the pathogenesis of psoriasis. Transforming growth factor (TGF) alpha may be an important regulatory factor of epidermal growth as overproduction of TGF-alpha is associated with epidermal hyperplasia in psoriatic plaques and epidermal growth factor receptors are overexpressed in psoriatic epithelium. In this study, the effects of cyclosporine on cultured human keratinocytes were examined. Cyclosporine specifically inhibited keratinocyte cell-cycle progression in the G1 phase without causing keratinocytes to terminally differentiate. Cyclosporine did not decrease the expression of TGF-alpha or epidermal growth factor receptors. These results suggest that the effects of cyclosporine on psoriatic skin are unrelated to direct effects on autocrine growth regulation of keratinocytes via TGF-alpha production or of epidermal growth factor receptor modulation.
Collapse
|
98
|
Increased dermal expression of platelet-derived growth factor receptors in growth-activated skin wounds and psoriasis. J Invest Dermatol 1991; 96:983-6. [PMID: 1646268 DOI: 10.1111/1523-1747.ep12476485] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Platelet-derived growth factor (PDGF) is a potent mitogenic and chemotactic factor for fibroblasts and other cell types. PDGF effects are mediated by binding of PDGF to dimeric PDGF receptors possessing intrinsic tyrosine kinase activity. We examined the expression pattern of PDGF receptors in cryostat sections of normal and growth-activated human skin using a monoclonal antibody, PR7212, specific for the beta subunit of the PDGF receptor. PDGF receptors were expressed at low levels in normal skin, with only occasional staining of dermal connective tissue cells. In contrast, PDGF receptor expression was greatly elevated in the dermis of growth-activated skin from 15 chronic wounds and 10 psoriatic lesions. PDGF receptors were increased in dermal fibroblasts and in dermal blood vessels in both conditions. Immunoblot analysis confirmed the increased expression of beta-subtype PDGF receptors in psoriatic lesional tissue. PDGF receptors were not detected in normal or growth-activated epidermis. Differential expression of PDGF receptors could regulate increased proliferation of vascular and connective tissue cells observed in psoriasis and chronic wounds.
Collapse
|
99
|
Abstract
Fixed drug eruptions (FDE) are immunologic reactions to drugs which produce erythematous plaques or blisters that characteristically recur at the same cutaneous sites with repeated antigenic challenges. While a detailed pathogenesis of these lesions remains obscure, T-lymphocyte infiltration has been documented repeatedly. In this study, we tried to determine if FDE were mediated, at least in part, by cytokines, such as gamma-interferon. We examined biopsies from 6 cases of clinically well-documented FDE with an HLA-DR antibody, LN3, and an antibody to gamma IP-10 (IP-10), a protein expressed by keratinocytes, monocytes, lymphocytes and endothelial cells following exposure to gamma-interferon. We found staining of the dermal lymphocytes with anti-HLA-DR antibody in all 6 cases examined. Keratinocytes and endothelial cells showed only focal staining at the antibody concentrations used. In addition, there was keratinocyte staining with the IP-10 antibody at all levels of the epidermis, with accentuation in areas of blister formation. There was more intense staining of keratinocytes with the IP-10 antibody in cases with accumulations of HLA-DR positive lymphocytes in the dermis. We believe that these findings are consistent with the hypothesis that FDE represent cell-mediated immunologic responses to a variety of antigens, and further, that the histologic alterations can be explained, at least in part, by a cytokine-mediated process.
Collapse
|
100
|
TGF-alpha and TGF-beta expression during sodium-N-butyrate-induced differentiation of human keratinocytes: evidence for subpopulation-specific up-regulation of TGF-beta mRNA in suprabasal cells. Exp Cell Res 1990; 191:286-91. [PMID: 2257881 DOI: 10.1016/0014-4827(90)90016-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sodium-N-butyrate (NaB) induces terminal differentiation and cornified envelope formation in cultured human keratinocytes. In the present study we explored the question of whether NaB-induced maturation could be mediated through changes in TGF-alpha and TGF-beta expression in normal keratinocytes. NaB induced a four-fold increase in TGF-beta mRNA transcript levels. This increase in TGF-beta mRNA abundance occurred only within the nonbasal keratinocyte subpopulation which maximally responds to NaB treatment by progression to cornified envelopes. Basal keratinocytes, which are relatively refractive to cornified envelope formation, did not show any increase in TGF-beta mRNA abundance after NaB treatment. By comparison, TGF-alpha mRNA transcript and extracellular TGF-alpha protein levels were unaffected by NaB treatment. A 50% decrease in EGF receptor binding was observed in NaB-treated keratinocyte cultures, rendering the cells less responsive to proliferation induction.
Collapse
|