Regenerative medicine can completely transform medical care and Japan is playing a leading role in this effort, according to Masayo Takahashi, a world-renowned stem cell researcher and ophthalmologist at the RIKEN Center for Biosystems Dynamics Research, speaking at the Rakuten Technology Conference 2018.
Regenerative medicine refers to an experimental branch of medicine that seeks to replace diseased cells, tissue or organs. The development of induced pluripotent stem (iPS) cells, which can be turned into any other type of cell, has served as rocket fuel for the field.
“With iPS cells, we can treat patients with their own cells, so we don’t have to use immunosuppressive drugs,” explained Takahashi in her keynote address at the event held in Rakuten Crimson House, Tokyo. iPS cells hold enormous potential to regenerate diseased tissue and organs and potentially cure serious chronic ailments such as blindness and neurological disorders.
Chasing big dreams
Takahashi shot to fame in 2014 when her colleagues at Kobe City Medical Center General Hospital performed the first transplant involving tissue derived from iPS cells. Working at the RIKEN Center for Developmental Biology (CDB), Takahashi reprogrammed a patient’s own skin cells and evolved them into retinal pigment epithelium iPS cells. The cells were implanted into the eye of the Japanese woman in her 70s who suffered from age-related macular degeneration, a common eye condition and a leading cause of vision loss in people over 50.
Takahashi recalled her early days working in a hospital in Kyoto, when she was a “timid person” without “big dreams.” All that changed after she began studying at the Salk Institute in the U.S. and became interested in the potential of stem cells. She shared a quote by Jonas Salk, remembered as the first to discover an effective vaccine for polio, that’s etched into the institute’s floor: “Hope lies in dreams, in imagination and in the courage of those who dare to make dreams into reality.”
The discovery of iPS cells by Kyoto University stem cell researcher Shinya Yamanaka, who shared the 2012 Nobel Prize for Physiology or Medicine with English biologist John Gurdon, galvanized Takahashi’s research. Since they can be developed from a patient’s own cells, iPS cells completely avoid the ethical concerns associated with embryonic stem cells, which can also become any type of cell.
Building new eyes, hearts and brains
A handful of other retinal transplants followed the landmark 2014 operation, and Takahashi and her colleagues are preparing results for a paper on their findings. Their success in the field has opened the door to other treatments such as transplants of photoreceptor cells for retinitis pigmentosa (RP), an inherited disorder that causes vision loss. Takahashi has been developing RP cells from iPS cells from other individuals, in this case because patients’ cells have gene mutations.
The U.S. Food and Drug Administration approved the world’s first retinal prosthesis, which works with a CCD camera and transmitter, for RP in 2013. But Takahashi believes that regenerative medicine holds out greater promise in the future because of its potential to target potential conditions early on.
“Now we’re treating only severe patients because the risk is small, but after we confirm the safety of these procedures, we can gradually treat patients in earlier stages of diseases,” Takahashi said in an interview on the sidelines of the conference. “Our ultimate goal may be that senescent [aging] tissue will be replaced before the disease manifests. But that could be in 50 years.”
Meanwhile, regenerative medicine is making strides elsewhere in Japan in world-first trials. Earlier this year, the Japanese government approved the use of iPS cells to treat heart disease in a study led by Yoshiki Sawa of Osaka University. Three people will be implanted with sheets of tissue made from iPS cells in a bid to regenerate cardiac muscle; if successful, the study will be expanded to 10 people, with an eye to commercializing the treatment.
“This is the start of industrialized regenerative medicine … but we’re still at the beginning, like the Wright Brothers’ flyer.”
Also this year, a Kyoto University Hospital team co-led by Takahashi’s husband Jun, a researcher at the university’s Center for iPS Cell Research and Application, launched a clinical study to treat Parkinson’s disease with iPS cells. While the study is small, involving only seven patients, the treatment has been shown to improve symptoms of the disease in monkeys, and hopes are high that it will work in humans too.
“This is the start of industrialized regenerative medicine, which will be very big in the future,” Takahashi told conference attendees during her keynote address. “But we’re still at the beginning, like the Wright Brothers’ flyer.”
For more about Rakuten Technology Conference 2018, visit here.