human stem cells

Researchers grow hairy skin from human stem cells

/ Yimy Villa / Leave a comment
 Dr. Jiyoon Lee (left) and Dr. Karl Koehler (right), Indiana University School of Medicine

For years the idea of being able to regrow hair has been the domain of cheesy, middle-of-the-night TV infomercials. Now two researchers may have found a way to actually make it happen, and their work could have implications far more important than helping bald men.

Building on years of research, Dr. Jiyoon Lee and Dr. Karl Koehler from the Indiana University School of Medicine were able to use human stem cells to grow hair on skin. The complex skin model was developed by using pluripotent stem cells, a kind of stem cell that can become virtually any kind of cell in the body.

To do this, Dr. Lee, Dr. Koehler, and a team of researchers incubated the human stem cells for 150 days. During this time, the cells formed a ball shaped cluster of cells called a skin organoid. The interior of the organoid is similar to the top layer of skin, known as the epidermis, and the outside is similar to the bottom layer, known as the dermis.

In a press release, Dr. Koehler describes the skin organoid and the process in more detail.

“We’ve developed a new cooking recipe for generating human skin that produces hair follicles after about 70 days in culture. When the hair follicles grow, the roots extend outward radially. It’s a bizarre-looking structure, appearing almost like a deep-sea creature with tentacles coming out from it.”

After the skin organoid was formed, the researchers tested if it could be integrated onto the skin of nude mice by performing skin grafts. The results were remarkable as more than half of the organoids that the scientists engrafted on the mice grew human hair follicles. The skin organoid developed is similar to fetal facial skin and hair.

This skin organoid model has great potential in terms of helping with drug or gene therapies for skin disorders or recreating the earliest stages of skin cancer formation.

In the same press release, Dr. Lee discusses the potential their findings have for reconstructive purposes.

“This could be a huge innovation, providing a potentially unlimited source of soft tissue and hair follicles for reconstructive surgeries.”

The full results of this study were published in Nature.

Gladstone scientists respond to coronavirus pandemic

/ Yimy Villa / 1 Comment

In these uncertain times, we often look to our top scientists for answers as well as potential solutions. But where does one begin to try and solve a problem of this magnitude? The first logical step is building on the supplies currently available, the work already accomplished, and the knowledge acquired.

This is the approach that the Gladstone Institutes in San Francisco is taking. Various scientists at this institution have shifted their current operations towards helping with the current coronavirus pandemic. These efforts have focused on helping with diagnostics, treatment, and prevention of COVID-19.

Diagnostics

Dr. Jennifer Doudna and Dr. Melanie Ott are collaborating in order to develop an effective method to rapidly diagnose those with COVID-19. Dr. Doudna’s work has focused on CRISPR technology, which we have talked about in detail in a previous blog post, while Dr. Ott has focused on studying viruses. By combining their expertises, these two scientists hope to develop a diagnostic tool capable of delivering rapid results and usable in areas such as airports, ports of entry, and remote communities.

Treatment

Dr. Nevan Krogan has discovered all of the human host cell proteins that COVID-19 interacts with to hijack the cell’s machinery. These proteins serve as new targets for potential drug therapies.

Since the high fatality rate of the virus is driven by lung and heart failure, Dr. Ott, Dr. Bruce Conklin, and Dr. Todd McDevitt will test effects of the virus and potential drug therapies in human lung organoids and human heart cells, both developed from human stem cells.

Dr. Warner Greene, who also focuses on the study of viruses, is screening a variety of FDA-approved drugs to identify those that could be rapidly repurposed as a treatment for COVID-19 patients or even as a preventive for high risk-groups.

Prevention

Dr. Leor Weinberger has developed a new approach to fight the spread of viruses. It is called therapeutic interfering particles (TIPs) and could be an alternative to a vaccine. TIPs are defective virus fragments that mimic the virus but are not able to replicate. They combat the virus by hijacking the cell machinery to transform virus-infected cells into factories that produce TIPS, amplifying the effect of TIPs in stopping the spread of virus. TIPs targeting COVID-19 would transmit along the same paths as the virus itself, and thus provide protection to even the most vulnerable populations.

You can read more about these groundbreaking projects in the news release linked here.

CIRM-Funded Scientists Make New Progress Toward Engineering a Human Esophagus

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Creating tissues and organs from stem cells—often referred to as ‘tissue engineering’—is hard. But new research has discovered that the process may in fact be a little easier than we once thought, at least in some situations.

Engineered human esophageal tissue [Credit: The Saban Research Institute].

Engineered human esophageal tissue [Credit: The Saban Research Institute].

Last week, scientists at The Saban Research Institute of Children’s Hospital Los Angeles announced that the esophagus—the tube that transports food, liquid and saliva between the mouth and the stomach—can be grown inside animal models after injecting the right mix of early-stage, or ‘progenitor,’ esophageal cells.

These findings, published in the journal Tissue Engineering Part A, are an important step towards generating tissues and organs that have been damaged due to disease or—in some cases—never existed in the first place.

According to stem cell researcher Tracy Grikscheit, who led the CIRM-funded study, the researchers first implanted a biodegradable ‘scaffold’ into laboratory mice. They then injected human progenitor cells into the mice and watched as they first traveled to the correct location—and then began to grow. The ability to both migrate to the right location and differentiate into the right cell type, without the need for any external coaxing, is crucial if scientists are to successfully engineer such a critical type of tissue.

“Different progenitor cells can find the right ‘partner’ in order to grow into specific esophageal cell types—and without the need for [outside] growth factors,” explained Grikscheit in a news release. “This means that successful tissue engineering of the esophagus is simpler than we previously thought.”

Grikscheit, who is also a pediatric surgeon as Children’s Hospital Los Angeles, was particularly hopeful with how their findings might one day be used to treat children born with portions of the esophagus missing—as well as adults suffering from esophageal cancer, the fastest-growing cancer in the U.S.

“We have demonstrated that a simple and versatile, biodegradable polymer is sufficient for the growth of a tissue-engineered esophagus from human cells. This not only serves as a potential source of tissue, but also a source of knowledge—as there are no other robust models available for studying esophageal stem cell dynamics.”

Want to learn more about tissue engineering? Check out these video highlights from a recent CIRM Workshop on the field.