This is a recurring column on early-stage research in animals or other laboratory models that has not yet entered the clinic but could have implications for future research and development of human medicines.
Creating new neurons in mice with Parkinson's
A group of researchers has created a treatment that can inhibit a protein called PTB in mice brains and effectively reverse the symptoms of Parkinson's disease.
The disease is a degenerative neurological disorder that predominantly affects dopamine-producing neurons in the brain. Patients typically experience tremors, limb rigidity and problems with walking and balance.
Researchers were able to increase dopamine production in mice by 30%.
In the study, published in the journal Nature on June 24, researchers discovered that after inhibiting PTB in mice, support cells called astrocytes in the brain transformed into dopamine-producing neurons.
"Researchers around the world have tried many ways to generate neurons in the lab, using stem cells and other means, so we can study them better, as well as to use them to replace lost neurons in neurodegenerative diseases. The fact that we could produce so many neurons in such a relatively easy way came as a big surprise," said Xiang-Dong Fu, professor at the University of California's San Diego School of Medicine, who led the research team.
The researchers administered a PTB antisense oligonucleotide treatment — which turns off the PTB protein — into the midbrains of one group of mice who had been induced to mimic the symptoms of Parkinson's disease, while giving a control group a mock treatment.
In the treated mice, some astrocytes turned into neurons and increased dopamine production by 30%. Within three months, these mice regained normal movement and showed no more signs of Parkinson's disease for the rest of their lives. Meanwhile, there was no improvement in the control group.
"It's my dream to see this through to clinical trials, to test this approach as a treatment for Parkinson's disease, but also many other diseases where neurons are lost, such as Alzheimer's and Huntington's diseases and stroke," said Fu.
Glowing dye improves cancer surgery in dogs
The University of Pennsylvania's Perelman School of Medicine and School of Veterinary Medicine teamed up to test a dye that illuminates cancer cells in order to more accurately detect and remove mammary tumors in dogs.
Dogs were injected pre-surgery with the glowing dye
Mammary cancer in dogs is very similar to breast cancer in humans, the researchers said, which made dogs ideal candidates for testing the dye.
The researchers injected the U.S. Food and Drug Administration-approved contrast agent indocyanine green, which glows under near-infrared light, into dogs prior to surgery. The results, published in the journal Plos One, confirmed that the dye accumulates in cancerous cells, highlighting both tumors and cancer cells that had spread to the dogs' lymph nodes.
"In women with breast cancer and also in dogs with mammary cancer, it's prognostic if the cancer has spread to the lymph nodes. What we showed was that we could identify both draining lymph nodes and lymph nodes with metastatic disease," said David Holt, a veterinary surgeon and senior author of the study.
Holt and other researchers from the medical school plan to continue testing how well these near-infrared dyes can identify cancer cells in patients and how surgeons can use them to achieve clean margins when removing tumors, which will likely limit the reoccurrence and spread of cancer.
Bioengineered uterine tissue leads to live rabbit births
A bladder scaffold is "seeded" with cells in the lab
A group of researchers at the Wake Forest Institute for Regenerative Medicine successfully bioengineered uterine tissue that was able to support live births by rabbits.
Tissue engineering uses scaffolds, or models, of tissues or organs that are combined with cells to create tissues that can be used in living beings or for research purposes.
In the study, published in Nature Biotechnology, the rabbits had portions of their uteruses removed and then were divided into three groups. One group was reconstructed using scaffolding seeded with autologous cells, meaning cells from the rabbits were including in the scaffolding, while another group was reconstructed with scaffolding that did not include the cells. The final group was repaired through suturing.
The rabbits with the cell-seeded constructs — four out of 10 of the rabbits — were able to give birth to live young and had pregnancies equivalent to those in the control group.
"Someday, with further development, the approach outlined in this paper may provide a regenerative medicine solution to uterine factor infertility. It will allow us to create a uterus for a woman from her own cells combined with biomaterials, eliminating the risk of rejection and the need for anti-rejection drugs," said Anthony Atala, director of the institute and author of the study. "When she is ready to have a baby, the organ will be ready to be activated."