iPSCs are not just pretty, they’re also pretty remarkable
Two Midwest universities are making headlines for their contributions to stem cell research. Both are developing important tools to advance this field of study, but in two unique ways.
Scientists at the University of Michigan (UM), have compiled an impressive repository of disease-specific stem cell lines. Cell lines are crucial tools for scientists to study the mechanics of different diseases and allows them to do so without animal models. While animal models have important benefits, such as the ability to study a disease within the context of a living mammal, insights gained from such models can be difficult to translate to humans and many diseases do not even have good models to use.
The stem cell lines generated at the Reproductive Sciences Program at UM, are thanks to numerous individuals who donated extra embryos they did not use for in vitro fertilization (IVF). Researchers at UM then screened these embryos for abnormalities associated with different types of disease and generated some 36 different stem cell lines. These have been donated to the National Institute of Health’s (NIH) Human Embryonic Stem Cell Registry, and include cell lines for diseases such as cystic fibrosis, Huntington’s Disease and hemophilia.
Using one such cell line, Dr. Peter Todd at UM, found that the genetic abnormality associated with Fragile X Syndrome, a genetic mutation that results in developmental delays and learning disabilities, can be corrected by using a novel biological tool. Because Fragile X Syndrome does not have a good animal model, this stem cell line was critical for improving our understanding of this disease.
In the next state over, at the University of Wisconsin-Madison (UWM), researchers are doing similar work but using induced pluripotent stem cells (iPSCs) for their work.
The Human Stem Cell Gene Editing Service has proved to be an important resource in expediting research projects across campus. They use CRISPR-Cas9 technology (an efficient method to mutate or edit the DNA of any organism), to generate human stem cell lines that contain disease specific mutations. Researchers use these cell lines to determine how the mutation affects cells and/or how to correct the cellular abnormality the mutation causes. Unlike the work at UM, these stem cell lines are derived from iPSCs which can be generated from easy to obtain human samples, such as skin cells.
The gene editing services at UWM have already proved to be so popular in their short existence that they are considering expanding to be able to accommodate off-campus requests. This highlights the extent to which both CRISPR technology and stem cell research are being used to answer important scientific questions to advance our understanding of disease.
CIRM also created an iPSC bank that researchers can use to study different diseases. The Induced Pluripotent Stem Cell (iPSC) Repository is the largest repository of its kind in the world and is used by researchers across the globe.
The iPSC Repository was created by CIRM to house a collection of stem cells from thousands of individuals, some healthy, but some with diseases such as heart, lung or liver disease, or disorders such as autism. The goal is for scientists to use these cells to better understand diseases and develop and test new therapies to combat them. This provides an unprecedented opportunity to study the cell types from patients that are affected in disease, but for which cells cannot otherwise be easily obtained in large quantities.
The Stem Cellar 
The embryonic stem cells allow the researchers to study structure and gene expression. The gene expression is regulated by transcription factor. Transcription factor is a protein to regulate up- or downregulation of gene to transcript mRNA. In some circumstances, some genes use it’s owned product as a transcription factor to modulate gene expression, such as tryptophan. The mutation of DNA may cause the shutdown of gene to produce transcription factor. Therefore, after gene editing of DNA by CRISPR-Cas9 technology, the next step is essential to activate the gene for transcription factor, to make sure the edited DNA can function normally.
The transcription of incorrect copy of DNA sequence produce the incorrect reading frame of mRNA. The wrong reading frame of mRNA is translated into abnormal protein. The abnormal protein lost the ability to function normally in animal model. Thus, animal model plays role to show the phenotype or symptoms of disease caused by the mutation gene. If the error of a single gene product cause human disease, the study of correcting the gene expression and regulation take account of a few steps only. Whereas, in most of cases, many of the human diseases involve various steps of biochemistry pathways to produce combination of biological products which are interplayed for biological function. Therefore, the genetic abnormality in one gene may cause other related genes shut off. Thus, animal models are essential to provide important clues to analyze each of biochemistry pathways.
In case, no animal model is available to represent for human diseases. The manipulation of gene in animals which are more closely related to human with CRISPR-Cas9 in animal stem cells may provide an important model to showoff the changing of genotype and phenotype in animal.
The understanding of genetic abnormality and biochemistry pathways are involved in human diseases may facilitate us to use iPSCs technology for regeneration of medicine. The abnormality of genetic human diseases in adult cells can be induced to iPSCs, corrected by CRISPR-Cas9, turning on and off of gene regulator as well as the genes involved in biochemistry pathway may produce normal, healthy and functioning cells for regeneration of medicine.