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. 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: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:Drug development costs a significant amount of time and resources for new pharmaceutical drugs. However, the progress has been limited for orphan diseases such as Duchenne muscular dystrophy (DMD). By using human induced pluripotent stem cells (hiPSCs), here we show an exemplary drug screening campaign and the identification of two potential drugs effective in a DMD mouse model. We developed a DMD-hiPSC screening platform utilizing high-content imaging to identify hit compounds that enhance myogenic fusion abilities of patient-specific myoblasts. Among 1524 compounds (Johns Hopkins Clinical Compound library), two hit compounds restored in vitro fusion defects of DMD patient hiPSC-derived myoblasts. Transcriptional profiling revealed that the function of two hit compounds, ginsenoside Rd (natural product, ginseng extract) and fenofibrate (FDA-approved drug), are associated with FLT3 signaling and TGF-β signaling, respectively. The preclinical tests in mdx mice show that the treatment of the two hit compounds can ameliorate the skeletal muscle and behavioral phenotypes caused by DYSTROPHIN deficiency, suggesting therapeutic potential of these two compounds. Our study demonstrates the feasibility of early-stage drug development for rare diseases using symptom-relevant cells derived from patient-specific hiPSCs.
Project description:Conventional embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) derived from primates resemble mouse epiblast stem cells, raising an intriguing question regarding whether the naïve pluripotent state resembling mouse embryonic stem cells (mESCs) exists in primates and how to capture it in vitro. Here we identified several specific signaling modulators that are sufficient to generate rhesus monkey fibroblast-derived iPSCs with the features of naïve pluripotency in terms of growth properties, gene expression profiles, self-renewal signaling, X-reactivation and the potential to generate cross-species chimeric embryos. Interestingly, together with recent reports of naïve human pluripotent stem cells, our findings suggest several conserved signaling pathways shared with rodents and specific to primates, providing significant insights for acquiring naïve pluripotency from other mammal species. In addition, the derivation of rhesus monkey naïve iPSCs also provides a valuable cell source for use in preclinical research and disease modeling. mRNA expression analysis of 4 rhesus monkey naive iPSC lines and 2 primed iPSC lines were examed.