Liver X-receptors alpha, beta (LXRs α , β) level in psoriasis Thesis Submitted for the fulfillment of Master Degree in Dermatology and Venereology BY Mohammad AbdAllah Ibrahim Awad (M.B., B.Ch., Faculty of Medicine, Cairo University) Supervisors Prof. Randa Mohammad Ahmad Youssef Professor of Dermatology, Faculty of Medicine Cairo University Prof. Laila Ahmed Rashed Professor of Biochemistry, Faculty of Medicine Cairo University Dr. Ghada Mohamed EL-hanafi Lecturer of Dermatology, Faculty of Medicine Cairo University Faculty of Medicine Cairo University 2011 ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ "وﻣﺎ ﺗﻮﻓﻴﻘﻲ إﻻ ﺑﺎﷲ ﻋﻠﻴﻪ ﺗﻮآﻠﺖ وإﻟﻴﻪ أﻧﻴﺐ" (هﻮد، ٨٨) Acknowledgement Acknowledgement First and foremost, I am thankful to God, for without his grace, this work would never have been accomplished. I am honored to have Prof.Dr. Randa Mohammad Ahmad Youssef, Professor of Dermatology, Faculty of Medicine, Cairo University, as a supervisor of this work. I am so grateful and most appreciative to her efforts. No words can express what I owe her for hers endless patience and continuous advice and support. My sincere appreciation goes to Dr. Ghada Mohamed EL-hanafi, Lecturer of Dermatology, Faculty of Medicine, Cairo University, for her advice, support and supervision during the course of this study. I am deeply thankful to Dr. Laila Ahmed Rashed, Assistant professor of biochemistry, Faculty of Medicine, Cairo University, for her immense help, continuous support and encouragement. Furthermore, I wish to express my thanks to all my professors, my senior staff members, my wonderful friends and colleagues for their guidance and cooperation throughout the conduction of this work. Finally, I would like to thank my father who was very supportive and encouraging. No words can make a dedication to match what he deserves. I am deeply thankful to my mother, for her love and support. I am indebted to my brother for his continuous care, advice and support. Abstract ABSTRACT Psoriasis has been recognized as a chronic inflammatory disease of the skin characterized by: an accelerated rate of keratinocyte proliferation, abnormal differentiation of epidermal keratinocytes, alteration in dermal angiogenesis and increased production of proinflammatory cytokines. Activation of LXRs stimulates keratinocyte differentiation, has an antiproliferative effect on keratinocyte and has an inhibitory effect on epidermal and TH 1 cytokines. The aim of this study was to to detect if there is a change in the expression of LXRs α and β in psoriatic skin or not, and if this change (if present) is related to severity of psoriasis or not. The levels of LXR α and β were measured in the lesional skin of psoriatic patients and in the control skin by PCR technique from 25 patients with plaque-type psoriasis as well as from 25age and sex matched controls. PASI score was assessed in the 25 psoriatic patients. The mean values of LXR α and β in the lesional skin of psoriatic patients were significantly lower than that in the control group (P Values for both LXR α and β were < 0.001). Correlating levels of LXR α and LXR β in the lesional skin of psoriatic patients of the studied cases to their PASI score showed a statistically significant inverse correlation i.e. the greater the PASI score is, the lower the level of LXR α and LXR β in the lesional skin of psoriatic patients. In conclusion, levels of LXR α and LXR β in the lesional skin of psoriatic patients were lower than controls and these low levels correlate inversely with the severity of psoriasis. Keywords: Psoriasis – Liver x receptors. Contents CONTENTS Page • List of Abbreviations ……………….……………………..…. I • List of Tables ………………………………………………… VIII • List of Figures …….………………………………………… IX • Introduction and aim of the work …………………….……………………………. 1 • Chapter 1: Psoriasis………………………………..…………………. 5 • Chapter 2: Liver x receptors…………………………….. 42 • Subjects and methods…….. 73 • Results………..…………..………..…………..………..………….. 83 • Discussion ………..…………..………..…………..………..………….. 107 • Conclusion and Recommendations………..………….. 111 • Summary ……………………….……….... 112 • References ………………………………………………..…. 114 • Arabic Summary ……………………………………….…… 129 LIST OF ABBREVIATIONS LIST OF ABBREVIATIONS ABC : ATP-binding cassette transporters. ACC : Acetyl CoA carboxylase. ACE : Angiotensin-converting enzyme inhibitors. AF : Activation function. AMPs : Antimicrobial peptides. AP-1 : Activator protein 1. APC : Antigen presenting cell. ApoE : Apolipoprotein E. AR : Androgen receptor. BMP-6 : Bone morphogenetic protein-6. CAR : Constitutive androstane receptor. CCHCR1 : Coiled-coil alpha-helical rod protein 1. CD4 : Cluster of differentiation 4. CD8 : Cluster of differentiation 8. cDNA : Complementary deoxyribonucleic acid. CDSM : Corneodesmosin. CGRP : Calcitonin gene related peptide. CLA : Cutaneous lymphocyte-associated antigen. COUP-TF : Chicken ovalbumin upstream promoter-transcription Factor. I LIST OF ABBREVIATIONS COX-2 : Cyclooxygenase-2. CRGP : Calcitonin gene related peptide. CTE : Carboxy-terminal extention. CYP51A1 : Cytochrome P450, family 51, subfamily A, polypeptide 1. CYP7A1 : Cholesterol 7 α hydroxylase or cytochrome P450 7A1. DAX-1 : Dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1. DBD : DNA binding domain. DC : Dendriric cells. DC-LAMP : Dendritic cell lysosome associated membrane protein. DNA : Deoxyribonucleic acid. EcR : Ecdysone receptor. EGF : Epidermal growth factor. EGF-R : Epidermal growth factor receptor. ER : Estrogen receptor. ERR : Estrogen-related receptor. ET-1 : Endothelin -1. FA : Fatty acid . FAS : Fatty acid synthase. FDFT1 : Farnesyl-diphosphate farnesyl transferase 1. FXR : Farnesoid X receptor. GC : Glucocorticoid. GCNF : Germ cell nuclear factor. II LIST OF ABBREVIATIONS GM-CSF : Granulocyte-macrophage colony stimulating factor. GR : Glucocorticoid receptor. HAT : Histone acetyltransferase. HDAC : Histone deacetylase. HDL : High-density lipoprotein. HDL-C : High-density lipoprotein cholesterol. HEV : High endothelial venule. HLA : Human leukocyte antigen. HLX : Homologue of the Drosophila tailless gene. HNF : Hepatocyte nuclear factor-4. HNF4α : Hepatocyte nuclear factor 4 alpha. HRE : Hormone response element. HSP : Heat shock protein. ICAM : Intercellular adhesion molecule. IFN-γ : Interferon gamma. IL : Interleukin. iNOS : Inducible nitric oxide synthase. IP-10 : IFN-γ-inducible protein 10. KGF : Keratinocyte growth factor . LBD : Ligand binding domain. LC : Langerhans cell . LDL : Low density lipoprotein. III LIST OF ABBREVIATIONS LFA : Leukocyte function associated antigen. LPL : Lipoprotein lipase. LRH-1 : Liver receptor homolog-1. LXR : Liver X receptor. MCP-1 : Monocyte chemotactic protein-1. MDC : Macrophage-derived chemokine. MHC : Major histocompatibility complex. MIG : Monokine induced by IFN-γ. MIP-1 : Macrophage inflammatory protein-1. MIP-1β : Macrophage inflammatory protein-1β MMP : Matrix metalloproteinase. MR : Mineralocorticoid receptor. MTX : Methotrexate. LXREs : LXR DNA response elements NCoR : Nuclear receptor corepressor. NF-1 : Nuclear factor 1. NFkappa B : Nuclear factor kappa-B (nuclear factor kappa-light-chain- enhancer of activated B cells). NGF : Nerve growth factor. NGFIB : Nerve Growth Factor IB-like. NK : Natural killer. NLS : Nuclear localisation signals. NOR1 : Neuron-derived orphan receptor-1. IV LIST OF ABBREVIATIONS NPC1L1 : Niemann-Pick C1-like 1. NPY : NeuropeptideY. NR : Nuclear receptor. NSAID : Non-steroidal anti-inflammatory drugs. NT : Neurotensin. Nur77 : Nerve growth factor-induced clone B. Nurr1 : Nuclear receptor related-1. PACAP : Pituitary adenylate cyclase-activating polypeptide. PASI : Psoriasis Area Severity Index. PCR : Polymerase chain reaction . PLTP : Phospholipid transfer protein. POMC : Proopiomelanocortin. PPAR : Peroxisome proliferators-activated receptor. PPP : Palmoplantar pustular psoriasis. PR : Progesterone receptor. PSORS : Psoriasis susceptibility locus. PSORS1 : psoriasis susceptibility locud 1. PXR : pregnane X receptor. RANTES : Regulated upon expression, normal T cell expressed and secreted. RAR : Retinoic acid receptor. RCT : Reverse cholesterol transport. RE : Response element. V LIST OF ABBREVIATIONS ROR : RAR-related orphan receptor. RT-PCR : Reverse transcriptase polymerase chain reaction. RXR : Retinoic x receptor. SCD-1 : Stearoyl CoA desaturase-1. SCF : Stem-cell factor. SF-1 : Steroidogenic Factor-like. SHP : Small heterodimer partner Germ. SKALP : Skin-derived antileukoproteinase. SMRT : Silencing mediator of retinoid acid and thyroid hormone. SP : Substance P. SREBP-1 : Sterol Regulatory Element-Binding Protein1. TARC : Thymus and activation regulated chemokine. Tc1 : Type 1 cytotoxic T cell. TCR : T-cell receptor. TF : Transcription factor. TG : Triglyceride. TGase K : keratinocyte transglutaminase type I. TGF-α : Transforming growth factor α. TGF-β : Transforming growth factor β. Th1 : T helper 1. TLRs : Toll like receptors. TNF-α : Tumour necrosis factor- α. VI LIST OF ABBREVIATIONS TR : Thyroid receptor. UGT1A3 : UDP glucuronosyltransferase1 family, polypeptide A3. VCAM : Vascular cell adhesion molecule. VDR : Vitamin D receptor. VEGF : Vascular endothelial growth factor. VIP : Vaso intestinal peptide. VLA-4 : Very late antigen 4. VPF : Vascular permeability factor. VII List of tables List of tables Table Title Page number number Table (1) : Calculation of PASI Score. 17 Table (2) : Cytokines and chemokines proposed to play a role in the 35 immunologic cascade of psoriasis. Table (3) : Key neuropeptides in the response