有效的方法显示脂肪细胞转换肝细胞

StephenW

Efficient method demonstrated for converting fat cells to liver cells

Wednesday 23 October 2013 - 1am PST

In a feat of modern-day alchemy with huge potential for regenerative medicine, Stanford University School of Medicine scientists have developed a fast, efficient way to turn cells extracted from routine liposuction into liver cells.

The advance is described in a study published in Cell Transplantation.

The scientists performed their experiments in mice, but the adipose stem cells they used came from human liposuction aspirates and became human, liver-like cells that flourished inside the mice's bodies. This method is distinct from those producing liver cells from embryonic stem cells or induced pluripotent stem cells. Although iPS and embryonic stem cells are pluripotent - they can, in principle, differentiate into every cell type - they carry a palpable risk of forming tumors. However, the cells produced using this new technique, which involves no intermediate pluripotent phase, show no signs of being tumorogenic.

The liver is the body's chemistry set. It builds complex biomolecules we need, and it filters and breaks down waste products and toxic substances that might otherwise accumulate to dangerous levels. Unlike most other organs, a healthy liver can regenerate itself to a significant extent. But this capacity cannot overcome acute liver poisoning or damage from chronic alcoholism or viral hepatitis.

Acute liver failure from acetaminophen alone takes about 500 lives annually and accounts for close to 60,000 emergency-room visits and more than 25,000 hospitalizations annually. Other environmental toxins, including poisonous mushrooms, contribute still more cases.

All aspects of the new fat-to-liver technique are adaptable for human use, said Gary Peltz, MD, PhD, professor of anesthesia and the study's senior author. Creating iPS cells requires introducing foreign and potentially carcinogenic genes. But adipose stem cells merely have to be harvested from fat tissue. The process takes nine days from start to finish - fast enough to regenerate liver tissue in acute liver poisoning victims, who would otherwise die within a few weeks, barring liver transplantation.

Some 6,300 liver transplants are performed annually in the United States, with another 16,000 patients on the waiting list. Every year, more than 1,400 people die before a suitable liver can be found for them. While it can save lives, liver transplantation is complicated, risky and, even when successful, fraught with aftereffects. Typically, the recipient is consigned to a lifetime of taking immunosuppressant drugs to prevent organ rejection.

"We believe our method will be transferable to the clinic," Peltz said. "And because the new liver tissue is derived from a person's own cells, we do not expect that immunosuppressants will be needed."

http://www.medicalnewstoday.com/releases/267770.php

StephenW

2013年10月23日（星期三） -  01:00 PST

在现代炼金术与再生医学的潜力巨大，斯坦福大学医学院的科学家们的壮举，已开发出一种快速，高效的办法把从常规吸脂提取到肝细胞的细胞。

提前发表的一项研究在细胞移植中描述。

科学家进行他们在老鼠实验中，但他们用脂肪干细胞来自人类抽吸物，成为人类肝细胞样细胞，老鼠的身体内蓬勃发展。这个方法是不同于那些从胚胎干细胞或诱导多能性干细胞，肝细胞。虽然IPS和胚胎干细胞是多能干细胞 - 它们可以在原则上，每一个细胞类型分化成 - 他们随身携带一个明显的形成肿瘤的风险。然而，使用这种新技术，不涉及中间的多能干阶段，没有迹象表明是tumorogenic的细胞产生。

肝脏是人体的化学组。我们需要建立复杂的生物分子，它过滤和分解废物和有毒物质，否则可能会累积到危险的水平。与大多数其他器官不同的是，一个健康的肝脏可以自我再生的显着程度。但是，这方面的能力无法克服慢性酗酒或病毒性肝炎的急性肝中毒或损坏。

单从对乙酰氨基酚急性肝功能衰竭需要约500人的生命，每年占接近60,000急诊室访问和每年超过25,000人住院。其他环境毒素，包括有毒蘑菇，贡献更多的情况下。

新的脂肪肝技术是适应人类使用的所有方面，说加里·佩尔茨，医学博士，博士，教授，麻醉和研究的资深作者。建立iPS细胞需要引进外国和潜在的致癌基因。但脂肪干细胞只是从脂肪组织中有所收获。这个过程需要9天，从开始到结束 - 速度不够快，再生肝组织急性肝中毒的受害者，否则将在几周内死亡，除非肝移植。

约6,300肝移植手术，每年在美国，另外16,000名患者在轮候名单上。每年，超过1400人死于前他们可以找到一个合适的肝脏。虽然它可以挽救生命，肝移植是复杂的，有风险的，即使成功，充满了后遗症。通常情况下，收件人委托的终生服用免疫抑制药物，预防器官排斥。

佩尔茨说： “我们相信，我们的方法将被转移到诊所， ” 。 “来自一个人自身的细胞，因为新的肝脏组织，我们不希望将需要免疫抑制剂。”

http://www.medicalnewstoday.com/releases/267770.php