Project description:Cross-species gene expression analysis of species-specific differences in preclinical assessment of pharmaceutical compounds (human)
Project description:Cross-species gene expression analysis of species-specific differences in preclinical assessment of pharmaceutical compounds (human)
Project description:Significant qualitative and quantitative differences exist between humans and the animal models used in research. However, significant quantitative and qualitative differences exist between humans and the animal models used in research. This is as a result of genetic variation between human and the laboratory animal. Therefore the development of a system that would allow the assessment of all molecular differences between species after drug exposure would have a significant impact on drug evaluation for toxicity and efficacy. Here we describe a cross-species microarray methodology that identifies and selects orthologous probes after cross-species sequence comparison to develop an orthologous cross-species gene expression analysis tool. The assumptions made by the use of this orthologous gene expression strategy for cross-species extrapolation is that; conserved changes in gene expression equate to conserved pharmacodynamic endpoints. This assumption is supported by the fact that evolution and selection have maintained the structure and function of many biochemical pathways over time, resulting in the conservation of many important processes. We demonstrate this difference using a cross-species methodology by investigating species specific differences of the peroxisome proliferator activator receptor (PPAR) alpha in rat and human.
Project description:Significant qualitative and quantitative differences exist between humans and the animal models used in research. However, significant quantitative and qualitative differences exist between humans and the animal models used in research. This is as a result of genetic variation between human and the laboratory animal. Therefore the development of a system that would allow the assessment of all molecular differences between species after drug exposure would have a significant impact on drug evaluation for toxicity and efficacy. Here we describe a cross-species microarray methodology that identifies and selects orthologous probes after cross-species sequence comparison to develop an orthologous cross-species gene expression analysis tool. The assumptions made by the use of this orthologous gene expression strategy for cross-species extrapolation is that; conserved changes in gene expression equate to conserved pharmacodynamic endpoints. This assumption is supported by the fact that evolution and selection have maintained the structure and function of many biochemical pathways over time, resulting in the conservation of many important processes. We demonstrate this difference using a cross-species methodology by investigating species specific differences of the peroxisome proliferator activator receptor (PPAR) alpha in rat and human.
Project description:Significant qualitative and quantitative differences exist between humans and the animal models used in research. However, significant quantitative and qualitative differences exist between humans and the animal models used in research. This is as a result of genetic variation between human and the laboratory animal. Therefore the development of a system that would allow the assessment of all molecular differences between species after drug exposure would have a significant impact on drug evaluation for toxicity and efficacy. Here we describe a cross-species microarray methodology that identifies and selects orthologous probes after cross-species sequence comparison to develop an orthologous cross-species gene expression analysis tool. The assumptions made by the use of this orthologous gene expression strategy for cross-species extrapolation is that; conserved changes in gene expression equate to conserved pharmacodynamic endpoints. This assumption is supported by the fact that evolution and selection have maintained the structure and function of many biochemical pathways over time, resulting in the conservation of many important processes. We demonstrate this difference using a cross-species methodology by investigating species specific differences of the peroxisome proliferator activator receptor (PPAR) alpha in rat and human. Rat primary hepatocytes were treated with 30 µM, 100 µM EMD and 0.1% DMSO as vehicle control. All samples were incubated at 24hr and 72hr intervals before RNA extrations and hybridization onto Affymetrix Rat microarrays.
Project description:Significant qualitative and quantitative differences exist between humans and the animal models used in research. However, significant quantitative and qualitative differences exist between humans and the animal models used in research. This is as a result of genetic variation between human and the laboratory animal. Therefore the development of a system that would allow the assessment of all molecular differences between species after drug exposure would have a significant impact on drug evaluation for toxicity and efficacy. Here we describe a cross-species microarray methodology that identifies and selects orthologous probes after cross-species sequence comparison to develop an orthologous cross-species gene expression analysis tool. The assumptions made by the use of this orthologous gene expression strategy for cross-species extrapolation is that; conserved changes in gene expression equate to conserved pharmacodynamic endpoints. This assumption is supported by the fact that evolution and selection have maintained the structure and function of many biochemical pathways over time, resulting in the conservation of many important processes. We demonstrate this difference using a cross-species methodology by investigating species specific differences of the peroxisome proliferator activator receptor (PPAR) alpha in rat and human. Human primary hepatocytes were treated with 30 uM, 100 uM EMD and 0.1% DMSO as vehicle control. All samples were incubated at 24hr and 72hr intervals before RNA extractions and hybridization onto Affymetrix human microarrays.
Project description:Fc receptors mediate the effector functions of therapeutic antibodies. Immunoglobulin G (IgG), the predominant antibody in circulation and clinical use, engages diverse Fc gamma (Fcγ) receptors that are expressed by multiple immune and structural cells. Here, we provide a comprehensive overview of Fcγ receptors and FcRn expression at both the transcriptomic and proteomic level in humans, macaques, and mice. We reveal species-specific differences in both Fcγ receptor diversity and cell-specific expression profile that compromise the translation of mouse and macaque preclinical models for antibody research. To overcome this, we generated a new mouse model in which human FcγRI (hCD64), FcγRIIA (hCD32A), FcγRIIB (hCD32B), FcγRIIIA (hCD16A), FcγRIIIB (hCD16B) is expressed under control of the relevant human promotors, replacing the murine counterparts (FcγRI, FcγRIIB, FcγRIII, and FcγRIV). Furthermore, to improve human antibody pharmacokinetics, murine FcRn was replaced by its human analog. We comprehensively mapped the expression of the knock-in receptors, and found that humanization led to much more faithful cell-specific Fcg receptor expression. We validated the functionality of these knock-in human receptors through in vitro and in vivo antibody-dependent cellular cytotoxicity, anaphylaxis and antigen presentation assays. This cross-species Fcγ receptor atlas and humanized mouse model with refined Fcg receptor expression and antibody pharmacokinetics will improve the preclinical assessment of antibody-based therapeutics.