Cultivating Human Kidneys in Pig Embryos; Dr. Saidi: A Long Way to Producing 'Transplantable Organs'

Dr. Reza Saidi Firouzabadi, head of the organ transplant department at the State University of New York, described the recent achievement of scientists in cultivating human kidneys within pig bodies as 'an important preliminary step,' but emphasized that there is still a long way to go before these organs can be used for transplantation in humans. Chinese scientists recently announced that they have been able to grow kidneys primarily made from human cells inside pig embryos. This is the first time a human organ has been grown in an animal's body. In recent years, significant advancements have been made to facilitate easier access for patients in need of transplants to their required organs, but substantial obstacles remain, making the growth of human cells in foreign hosts challenging. Regarding this significant scientific development, Dr. Saidi Firouzabadi told Voice of America that, in addition to the new method developed by Chinese scientists, which has a long way to go before fruition, other advancements have also been made in this field that have reached practical stages. For instance, at two centers in Alabama and New York, genetically modified pig kidneys were transplanted into a patient who was brain dead. Several studies have shown that the pig kidneys transplanted into brain-dead individuals were able to produce urine for a short period, which is one of the essential functions of kidneys. However, research from the University of Alabama - Birmingham first demonstrated that these transplanted kidneys were also able to filter blood creatinine, which is another important function of the kidneys. In a similar study at the University of Maryland, a pig heart was transplanted into a 57-year-old patient who survived for two months before dying from an infection. Dr. Saidi Firouzabadi stated that this indicates that transplanting animal organs into humans could lead to the transmission of infections, and what is not pathogenic in pigs could be dangerous for humans, which is why scientists are working on this issue. He explained that pigs are typically used for such experiments because they reproduce multiple times and their organs are similar in size to those of humans. In response to the question of whether using pigs could create religious barriers, he stated that various religions, including Islam, accept methods that lead to saving human lives. He mentioned that in Iran, many medical products derived from pigs are used, such as pig insulin and other medications. If individuals can receive organs formed from their own stem cells, the likelihood of organ rejection decreases. Pig cells tend to outpace human cells during development, meaning that what ultimately results is almost entirely pig. Genetic modification of single-cell pig embryos by researchers from biomedical and health institutes in Guangzhou, the Chinese Academy of Sciences, and Wuyi University overcame this problem. They genetically manipulated the pig using CRISPR technology to prevent it from being able to grow kidneys. Human stem cells were also optimized to allow the cells to survive long enough to find their place and begin forming kidneys. After being transferred to the pig, the pregnancy was terminated after 28 days for study. The result was that the embryos all had normal kidneys according to their growth stage, containing over 60% human-derived cells. A human kidney has over 70 unique cell types, and until researchers can create an organ that is 100% human, the risk of organ rejection remains. In the United States alone, over 100,000 people are on the organ transplant waiting list, most of whom need kidney transplants. Dr. Saidi Firouzabadi told Voice of America that one in seven people in the U.S. has chronic kidney disease, and in Iran, a field study conducted a few years ago by Dr. Behrouz Boroumand and Ali Nobakht showed that one in four Iranians has varying degrees of kidney failure. Therefore, exploring various methods for easier access to kidneys for patients could save many lives. Another significant challenge with the Chinese scientists' method is that human cells could end up in the brains or reproductive systems of animals, potentially leading to the production of sperm or eggs that contain human genes or the growth of animals with human brains, creating an ethical dilemma. Thus, researchers will have to make further genetic modifications to human stem cells to prevent this issue, which will require several years of continuous effort. Dr. Saidi stated that if studies of this kind become more complete and accessible to the public, there is hope that patients in Iran will also benefit from it, but there is still a long way to go.