糖尿病一型基因发现

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Diabetes gene found
NEW DELHI: In a discovery that could help prevent children from becoming diabetic, scientists have found a gene that increases a child's risk for type 1 diabetes.

In the breakthrough, scientists have found that the gene KIAA0350 on chromosome 16 triggers the immune system cells to attack the pancreas. It is the loss of insulin-producing islet cells in the pancreas that causes type 1 or juvenile diabetes. The team from the Children's Hospital of Philadelphia and McGill University in Montreal have announced their findings in the July 15 issue of the journal Nature.

During the study, investigators examined the genomes of 1,046 children with type 1 diabetes from paediatric diabetes clinics in Philadelphia and four Canadian cities. The researchers then compared the genomes of 563 patients with type 1 diabetes with those of 1,146 matched control subjects.

The researchers confirmed the four previously identified genes contributing to type 1 diabetes, but also stumbled upon a new type 1 diabetes variation on chromosome 16, occupied by the gene KIAA0350.

Hakon Hakonarson, director of the Centre for Applied Genomics at the Children's Hospital of Philadelphia, said, \"The role of KIAA0350 needs to be investigated. However, a special cell type called a natural killer (NK) cell expresses this gene abundantly. Our hypothesis is that a special mutation in KIAA0350 may influence the sugar binding of the protein and trigger an autoimmune response that activates these NK cells in such a way that they attack and destroy the islet cells in the pancreas, resulting in type 1 diabetes.\"

\"A particular version of the gene protects against this inappropriate autoimmune response, while a different version of the gene makes it more likely to happen,\" he added. According to Dr Anoop Mishra from Fortis, a complicated disease like diabetes will have atleast 8-10 genes that influence various aspects of the disease. While some will trigger diabetes early, others will cause complications early or lead to higher BP in some patients. Some genes will also control all aspects of the disease.

This research adds a new gene to the four genes previously discovered for type 1 diabetes, in which the immune system destroys insulin-producing beta cells in the pancreas and makes patients dependent on frequent insulin injections to keep the body's blood sugar under control.

Constantin Polychronakos, director of Paediatric Endocrinology at McGill University, said that better knowledge of genes that predispose to type 1 diabetes may later enable physicians to screen newborns to predict those at high risk for the disease. \"If we know the gene pathways that give rise to type 1 diabetes, we hope to intervene early in life with targeted drugs or cell therapies to prevent the disease from developing,\" said Polychronakos.
新德里：科学家们已经发现增加儿童患1型糖尿病风险的基因，该发现有助于预防儿童糖尿病。
在这突破性的研究中，科学家们发现位于16号染色体的KIAA0350基因，可触发免疫细胞攻击胰腺。分泌胰岛素的胰岛细胞缺失是引起1型糖尿病或青少年糖尿病的原因。来日费城儿童医院和蒙特利尔麦吉尔大学的研究组在7月15日的《自然》发表了他们的研究结果。
在研究期间，研究人员检测了在费城和4个加拿大城市的儿童糖尿病门诊就诊的1046例1型糖尿病儿童的染色体。然后对比了563例1型糖尿病患者的染色体与这1146个研究对象的区别。
研究者证实了前期研究的发现——4个基因与1型糖尿病有关，但无意中还发现了一个位于16号染色体的与1型糖尿病有关的新基因——KIAA0350。
费城儿童医院应用基因体学中心的负责人Hakon Hakonarson说：“KIAA0350基因的作用需要进一步研究。然而一种特殊的细胞——NK细胞可大量表达这种基因。我们假设：KIAA0350基因特殊的突变会影响糖与蛋白结合，并诱发自身免疫反应，从而激活NK细胞，攻击破坏胰岛细胞，导致1型糖尿病。”
他补充说道“该基因的某种特殊表型可保护机体免受这种异常自身免疫反应，然而另外一种模式则可能诱发异常的自身免疫反应”。Fortis的Anoop Mishra博士认为，像糖尿病这种复杂的疾病至少受8-10个基因的影响，影响包括疾病的各个方面。一些基因在早期诱发糖尿病，其他一些基因诱发并发症或导致高血压。一些基因还可能对该疾病起综合控制作用。
该研究给前期发现的4个1型糖尿病相关基因增加了一个“新队友”， 1型糖尿病胰岛beta细胞受免疫损伤，使得病人依赖于频繁的胰岛素注射以控制血糖水平。
麦吉尔大学儿科内分泌学的负责人Constantin Polychronako说：更多的了解诱发1型糖尿病基因的知识，可以使医生对新生儿进行检测，预测患糖尿病的风险。“如果我们知道基因诱发糖尿病的机理，我们有希望用靶向药物或者细胞疗法在生命的早期阶段进行干预，以防止糖尿病的发展。”