Corticosteroid Pharmacological Effects

Transcription

1 Page 1 of 1 Corticosteroid Pharmacological Effects William J. Jusko, Ph.D. Department of Pharmaceutical Sciences ACoP 3/1/8 Immunological Effects Immunosuppressive Anti-inflammatory Metabolic Effects Carbohydrate metabolism Lipid metabolism Protein metabolism Treatment for Immune Related Diseases - Rheumatoid arthritis - Lupus erythematosus - Bronchial asthma - Organ transplantation Adverse Effects steroid diabetes abnormal fat distribution muscle wasting negative nitrogen balance Capacity-Limitation Turnover and Homeostasis Effect, % E E = EC Concentration max γ γ C γ + C Hill Function The Law of Mass Action ( D + R DR ) and small quantity of targets leads to capacity-limitations in most responses. Production dr = k Biological Factor (R) production k loss Loss R Both diseases and therapeutic agents often interfere with the homeostasis in the body resulting from the natural turnover of biological substances or functions.

2 Page 2 of 1 Giant Rat Experiments: Single- dosing and chronic infusion regimens. PK assessment. Parallel Analysis of Multiple Tissues: Liver, muscle, kidney, fat, etc. Molecular Biology: Gene Arrays and QRTPCR of selected genes. Biochemistry: Measurement of relevant gene products (proteins and enzymes), and signals. Systems Physiology: Blood glucose, insulin, lipid profiles, others Disease Models: Diabetes, Arthritis, Pregnancy. Development of Mechanism-Based PK/PD/PG/DIS Catabolic Metabolic/Genomic Effects of Corticosteroids Tyrosine Aminotransferase (TAT) Anabolic Models. Dhahbi et al, American Journal of Physiology, E352-6 (1999). Pharmacogenomics: Drugs & Genes & Models Drug + Receptor Fifth-Generation Model for Corticosteroid Pharmacodynamics: Application to Steady-State Receptor Down-Regulation and Enzyme Induction Patterns during Seven-Day Continuous Infusion of Methylprednisolone in Rats Giant Rat Study DNA ± Production Loss + Production Loss Protein R. Ramakrishnan, DC Debois, RR Almon, NA Pyszczynski, and WJ Jusko, J. Pharmacokin. Pharmacodyn. 21: 1-24 (2).

3 Page 3 of 1 Methylprednisolone PK/PD/PG in Rats Corticosteroid Pharmacogenomics MPL Concentration (ng/ml) DR(N) Concentration (fmol/mg protein) Time (hr) GR mrna (fmole/g liver) GR density (fmole/mg protein) PK GR mrna TAT mrna Time (hr) TAT mrna (pmole/g liver) TAT Activity (Δ A/min/mg protein) DR(N) Cytosol GR TAT Time (hr) I(t) k srm D k sr k on + k dr mrna R R k slr S LR k drm DR R f *k re Liver Weight k T DR(N) (1-R f ) *k re k syn S k dlr mrna TAT Fifth-generation model Ramakrishnan et al JPP 21: 1 (2). k deg EF k deg T TAT PHARMACOKINETICS Model Equations " D" RECEPTOR DYNAMICS dr = ksr mrnar + R f kre DR( N ) k ddr ddr = k dmrna R on ( N ) = k = k mrna D R k T srm T DR k 1 IC mrna DR re DR( N ) Rm λ1 t λ2 t = C P = C1 e + C2 e DR( N ) k DR N + ( ) LR D R k drm k = mrna srm R = obs drm mrnar on k k dr R R sr = mrnar R k dr Model Equations LIVER WEIGHT RATIO dlr = kslr (1 + SLR DR( N )) k mrna DYNAMICS dmrna dlr LR = ksyn (1 + S P DR( N )) kdeg mrna = mrna obs LR mrna k syn = k deg mrna TAT DYNAMICS dtat = kst (1 + STAT mrna) kdegt TAT TAT TAT = TATobs LR kst = kdegt mrna

4 Page 4 of 1 Gene Arrays GR mrna (fmole/g liver) GR mrna GENE TREE: 4373 of 8799 Probe Sets: Filtered based on genes expressed in liver Time (hr) E I S E N P L O T Affymetrix Rat Gene Microarray Patterns: 192 / 8799 Genes 7. Silicon Genetics Inc. Pattern Searches: User-Defined Profiles Self-Organizing Maps K-Means Clustering Filtration System: Low Variability 4 t i > t i <.65 PK/PD Modeling (Adapt II) Jin JY, Almon RR, Dubois DC, Jusko WJ, JPET 37: (3).

5 Page 5 of 1 Extracting Global Systems Dynamics of Corticosteroid Genomic Effects in Rat Liver E Yang, RR Almon, DC DuBois, WJ Jusko, IP Androulakis, JPET, in press (8). Genes hashing to same integer belong to same cluster. n = 529 genes Clusters of dynamic response patterns in tissues suggest that a limited array of control processes account for pharmacogenomic effects of steroids. Baseline versus Chronic versus Acute dosing reveals myriad complexities in gene homeostasis. Response profiles and PK/PD models offer opportunities to formulate hypotheses regarding factors and mechanisms of genomic effects. Data available at:

6 Page 6 of 1 Rats with Collagen Induced Arthritis Male Rats Age : 6-9 weeks Weight: Matched to ~175 g Induce Arthritis & sacrifice at various times (days 9,12,15,17,19,21,23,25,3,34) up to day 34: for collection of paw tissue, plasma. Non-invasive Disease Endpoints: Paw Edema, Body Weight, Bone Mineral Density Various dosing regimens of dexamethasone. Justin C. Earp: Trying to gain their trust Arthritic Rats Healthy Controls 6 8 Rheumatoid Arthritis: Disease Pathology Immune Cells Migration Proliferation Cyto/Chemo-kines: TNF-α, IL-1β, IL- 6, IFN-γ, GM-CSF Prostaglandins Nitric Oxide Rheumatoid Factor Edema Joint Tissue Erosion: Bone Cartilage Synovial Tissue Choy HS, et al. (1) NEJM.

7 Page 7 of 1 Healthy IL-6 TNF-α IL-1β Arthritic Neeck G, Renkawitz R, Eggert M 2. Cytokines Cell Mol Ther 7(2): Paw Glucocorticoid Receptor mrna & Corticosterone in Plasma GR mrna Corticosterone Bone Mineral Density by Dual-Energy X-Ray Absorptiometry (Piximus, GE) GR mrna (ng_mrna/mg_total_rna) Corticosterone Concentration (ng/ml) Total Femur Diaphyseal Femur Metaphyseal Femur Epiphyseal Femur

8 Page 8 of 1 Bone Mineral Density (g/cm 2 ) Bone Mineral Density: Femur & Lumbar Diaphyseal Femur Metaphyseal Femur Epiphyseal Femur.175 Lumbar Vertebrate Doses: 2.25 and.225 mg/kg 1 IM Dose C T k V (F) A T C P V P CL CL D Open: Controls; Closed: RA Healthy Rats TIME (hr) Arthritic Rats TNF-α mrna (ng_mrna/mg_total_rna) High Dose: 2.25 mg/kg Low Dose:.225 mg/kg Disease Progression IL-6 mrna (ng_mrna/mg_total_rna) IL-1β mrna (ng_mrna/mg_total_rna) DEX PD: Paw Glucocorticoid Receptor mrna DEX PD: Plasma Corticosterone Disease Progression High Dose: 2.25 mg/kg Low Dose:.225 mg/kg GR mrna (ng_mrna/mg_total_rna) Corticosterone (ng/ml)

9 Page 9 of 1 Acute & Chronic DEX PD: Paw Edema Chronic DEX PD: Bone Mineral Density Disease Progression Chronic:.225 mg/kg Acute: 2.25 mg/kg Acute:.225 mg/kg Healthy Rats: ο.45 mg/kg, once daily, 7 days (4 rats) Δ.225 mg/kg, once daily, 7 days (4 rats) Arthrtic Rats:.225 mg/kg, once daily, 7 days (6 rats).225 Total Femur DEX RA PD Systems Model Dex pharmacokinetics. Adrenal suppression by Dex. 5 th -Gen Receptor/Gene control (Dex, CST). RA up-regulation of cytokine mrna. Transductional control of BMD. Joint cytokine production of edema. Indirect response models for multi-component interactions.

10 Page 1 of 1 Assessment of the kinetics and responses of steroids have offered numerous insights into mechanism-based PK/PD/Disease models. Drug-alterations of biological systems help probe underlying control steps. Models can integrate PK, receptor, gene, physiology, and disease processes. Models help formulate or alter hypotheses and design new experiments. Collaborators Richard R. Almon, PhD Debra C. DuBois, PhD Ioannis Androulakis, PhD Eric Hoffman, PhD NIH Grants GM GM-5798 GM-676 Technicians Nancy A. Pyszczynski Suzette M. Mis PhD Students (Recent) Yu-Nien (Tom) Sun, PhD Rohini Ramakrishnan, PhD Donald E. Mager, PhD Mahesh Samtani, PhD Ana Hazra, PhD Zhenling Yao, PhD Eric Yang, PhD Justin Earp, PhD and many previous fellows and students.