水晶體幹細胞 用於 幼兒 白內障 治療

幹細胞再生治療白內障 獲重大突破 2016年03月10日 09:26 林芳如／綜合報導 治療白內障重大突破！大陸中山大學和美國加州大學聖地亞哥分校科學家最新研究，利用幹細胞再生技術，在眼睛內長出新的水晶體，成功地為大陸兒童治療白內障。據英國BBC報導，全世界有大約2000萬人因白內障失明，這種疾病好發於年長者，年紀大老化是最常見的原因，另有部分兒童患有先天性的白內障。目前傳統治療方法多用超聲波將水晶體乳化後吸出，隨後再植入人工晶狀體。但這種手術易在兒童身上出現併發症。科學家最新治療方法，是通過一個微小切口取出混濁水晶體，但保持水晶體囊外層完好無損，水晶體囊上有很多皮膜幹細胞，具修複損傷功能。保存這些幹細胞進行水晶體再生。該研究首先在兔子和猴子身上試驗成功，接著又對12名大陸兒童進行試驗，由於兒童的水晶體皮膜幹細胞相當年輕，容易再生，8個月後，重新長出的水晶體已達到一般尺寸。張康博士說，這是第一次再生完整的水晶體，但在應用於標凖治療前，還需更大規模試驗。不過，白內障患者仍以老年人居多，科學家已開始針對年長者進行試驗，結果令人鼓舞。倫敦國王學院幹細胞科學家埃利克博士（Dr Dusko Ilic）表示，這是迄今為止再生醫學領域最好的成果之一。本研究結果發表於《自然》雜誌。(中時即時)

Lens regeneration using endogenous stem cells with gain of visual function

Nature (2016) doi:10.1038/nature17181, Received 13 October 2014 Accepted 29 January 2016 Published online 09 March , The repair and regeneration of tissues using endogenous stem cells represents an ultimate goal in regenerative medicine. To our knowledge, human lens regeneration has not yet been demonstrated. Currently, the only treatment for cataracts, the leading cause of blindness worldwide, is to extract the cataractous lens and implant an artificial intraocular lens. However, this procedure poses notable risks of complications. Here we isolate lens epithelial stem/progenitor cells (LECs) in mammals and show that Pax6 and Bmi1 are required for LEC renewal. We design a surgical method of cataract removal that preserves endogenous LECs and achieves functional lens regeneration in rabbits and macaques, as well as in human infants with cataracts. Our method differs conceptually from current practice, as it preserves endogenous LECs and their natural environment maximally, and regenerates lenses with visual function. Our approach demonstrates a novel treatment strategy for cataracts and provides a new paradigm for tissue regeneration using endogenous stem cells.

Cataracts can be cured by using a patient's own stem cells to regrow a 'living lens' in their eye, restoring sight in just three months, scientists have shown.

In research described as 'remarkable,' surgeons reversed blindness in 12 infants born with congenital cataracts by removing the damaged lens and coaxing nearby cells to repair the damage. It could pave the way for millions of older people in Britain having their sight restored using their own cells. Currently, cataracts are treated by inserting an artificial plastic lens into the eye, but that can lead to infections, inflammation and a night time halo effect in vision. For babies the risks from surgery are even greater because the eye is still developing. But using the new technology scientists at the University of California, San Diego, showed that cataracts without the need for a transplant. They now plan to start work on age-related cataracts which occur when clumps of protein build up over time, creating a clouding effect. "An ultimate goal of stem cell research is to turn on the regenerative potential of one's own stem cells for tissue and organ repair and disease therapy," said Dr Kang Zhang, chief of Ophthalmic Genetics and founding director of the Institute for Genomic Medicine at UC San Diego School of Medicine. "The success of this work represents a new approach in how new human tissue or organ can be regenerated and human disease can be treated, and may have a broad impact on regenerative therapies by harnessing the regenerative power of our own body. Cataract surgery is now the most common surgical procedure undertaken in England with around 300,000 operations performed annually on the NHS. The procedure involves removing the clouded lens and inserting an artificial plastic version, called at intraocular lens. But a large number of patients undergoing surgery are left with poor vision and still need to wear glasses for driving or reading a book. The new technique removes the lens but leaves behind the lens capsule - a membrane that helps give the lens its required shape to function. Nearby regenerative stem cells are then moved to the membrane where they begin to grow into a new, fully functioning and transparent lens. The procedure was carried out on 12 infants under the age of two who healed far more quickly and without complication compared with a group of 25 youngsters who had a traditional plastic lens fitted After three months, a clear, regenerated curved lens have developed in all of the trial patients' eyes. Nearly 300 babies are born with congential cataracts each year in Britain. Dr Dusko Ilic, Reader in Stem Cell Science, King's College London, described the trial as a 'remarkable accomplishment.'"This is one of the finest achievements in the field of regenerative medicine until now," said. "The basic science research led to the hypothesis that preserving and stimulating stem cells in the eye might promote regeneration of a surgically removed lens."And indeed, their hypothesis was true. They proved it first by testing a new surgical approach in rabbits and primates before successfully treating 12 infants. It is science at its best." Prof Graham McGeown, Deputy Head of the School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, said the research could lead to 'an important new treatment.'"They showed that this new approach dramatically reduced the risk of sight damaging side effects when compared with the current 'best practice' treatment, which involves more destructive surgery followed by implantation of an artificial lens." In a separate study, scientist at Cardiff University and Osaka University in Japan showed that they could use stem cells to regenerate several types of tissue from the eye in one go. When transplanted into a rabbit, the tissue was shown to reverse blindness, paving the way for human trials, which could see vision restored in people with a range of sight problems. Professor Andrew Quantock, of Cardiff University, said: "This research shows that various types of human stem cells are able to take on the characteristics of the cornea, lens and retina."Importantly, it demonstrates that one cell type - the corneal epithelium - could be further grown in the lab and then transplanted on to a rabbit's eye where it was functional, achieving recovered vision." Around 4000 corneal grafts are performed by the NHS annually, which rely on human organ donation. Prof Julie Daniels, of UCL, said: "These two studies illustrate the remarkable regenerative and therapeutic potential of stem cells. Lens regeneration might also turn out to be possible in ageing adults." Both studies were published in the journal Nature.