干细胞可以活多久

干细胞可以活多久 How Long Do Stem Cells Live? ScienceDaily (Mar. 4, 2011) — When patients receive a bone marrow transplant, they are getting a new population of hematopoietic stem cells. Fresh stem cells are needed when a patient is low on red blood cells, as in anemia, or white blood cells, which can be caused by cancer or even cancer treatments such as irradiation or chemotherapy. The problem is that a bone marrow transplant might not succeed because the transplanted stem cells don't live long enough or because they proliferate too well, leading to leukemia. To help determine how long a bone marrow (stem cell) graft will last, researchers at Sanford-Burnham Medical Research Institute (Sanford-Burnham) have developed a mathematical model that predicts how long a stem cell will live and tested those predictions in a mouse model. The study, led by Christa Muller-Sieburg, Dr. rer. nat., was published online the week of February 28, in the journal Proceedings of the National Academy of Sciences. "It has long been assumed that stem cells are immortal -- they continue to self-renew, thus generating more stem cells that collectively can outlast an individual's life," said Dr. Muller-Sieburg, professor in Sanford-Burnham's Stem Cells and Regenerative Biology Program. "But now we have found that each stem cell is pre-programmed to self-renew only for a set amount of time that, in mice, ranges from a few months to several years. So we created a computer program that predicts that lifespan." Researchers drew blood from transplant recipients, took a few initial measurements of the mature white blood cells generated from the transplant, and entered those parameters into a computer program that predicts their lifespan. This information was then compared to the stem cells' true lifespan. Some stem cells lasted five months and others more than three years, but again and again the computer program predicted survival time with surprising accuracy. Dr. Muller-Sieburg and her colleagues found that stem cell self-renewal is strictly regulated to successfully negotiate a precarious balance: too much self-renewal results in leukemia, while too little leads to bone marrow failure. This new understanding now allows them to better predict the conditions that lead to normal stem cell proliferation. Not only are these findings relevant to bone marrow transplants, they could also have implications for regenerative medicine. The safety and efficacy of using embryonic and other stem cells for tissue regeneration will depend on harnessing and precisely controlling their proliferative capacity. By providing a better understanding of how stem cells proliferate, and when they die, this lifespan prediction program could help improve their therapeutic potential for diabetes, Alzheimer's disease and other conditions. Mathematical modeling has other benefits, too. According to lead author Hans Sieburg, Dr. rer. nat, "Computer simulation allows us to generate a hypothesis, make predictions about what should be true, and then better plan our experiments in a way that requires fewer animal experiments." How Long Do Stem Cells Live? 干细胞能存活多久, ScienceDaily (Mar. 4, 2011) — When patients receive a bone marrow transplant, they are getting a new population of hematopoietic stem cells. Fresh stem cells are needed when a patient is low on red blood cells, as in anemia, or white blood cells, which can be caused by cancer or even cancer treatments such as irradiation or chemotherapy.The problem is that a bone marrow transplant might not succeed because the transplanted stem cells don't live long enough or because they proliferate too well, leading to leukemia. 《科学日报》2011年3月4日报导-患者接受骨髓移植手术后，可获得一群新的造血干细胞。这 种新的造血干细胞适用于贫血等红细胞性偏低以及癌症或癌症放化疗导致的白细胞偏低等情况 的治疗。然而这类干细胞移植面临的问题是:移植的干细胞可能存活不久而导致骨髓移植失败， 或者这类细胞可能增殖分化异常导致白血病发生。 To help determine how long a bone marrow (stem cell) graft will last, researchers at Sanford-Burnham Medical Research Institute (Sanford-Burnham) have developed a mathematical model that predicts how long a stem cell will live and tested those predictions in a mouse model. The study, led by Christa Muller-Sieburg, Dr. rer. nat., was published online the week of February 28, in the journal Proceedings of the National Academy of Sciences. 为帮助确定骨髓(干细胞)移植物的存活时间，桑福德-伯纳姆医学研究所(桑福德伯纳姆)的 研究人员最近开发了一种用于预测干细胞存活时间的数学模型，并在大鼠模型中对这种模型的预 测效果进行了评价。这项研究是由Christa MSieburg博士负责的，研究结果2月28日在线发表 在Proceedings of the National Academy of Sciences杂志上。 "It has long been assumed that stem cells are immortal -- they continue to self-renew, thus generating more stem cells that collectively can outlast an individual's life," said Dr. Muller-Sieburg, professor in Sanford-Burnham's Stem Cells and Regenerative Biology Program. "But now we have found that each stem cell is pre-programmed to self-renew only for a set amount of time that, in mice, ranges from a few months to several years. So we created a computer program that predicts that lifespan." 桑福德-伯纳姆干细胞和再生生物学项目教授，Muller-Sieburg博士评论说:“长久以来，人们一 直认为干细胞是不会死亡的，它们在人的一生中可以不停的自我更新，不断产生更多的干细胞。 但是我们现在发现每个干细胞其实都只是在一定的时间范围内能够按照预定的进行自我更 新，对于小鼠，这个时间范围从几个月到几年不等。因此，我们建立一个计算机程序来预测干细 胞的生存时间”。 Researchers drew blood from transplant recipients, took a few initial measurements of the mature white blood cells generated from the transplant, and entered those parameters into a computer program that predicts their lifespan. This information was then compared to the stem cells' true lifespan. Some stem cells lasted five months and others more than three years, but again and again the computer program predicted survival time with surprising accuracy。 研究人员抽取了受移植小鼠的血液，对移植产生的成熟白细胞进行了一些初步测定，并将这些参 数输入计算机程序进行干细胞寿命的预测，然后将预测出干细胞寿命和干细胞的实际寿命进行比 较。一些干细胞的寿命在5个月左右，另一些则超过3年，采用前面描述的方法进行了多次比 较，令人惊奇的是，每次计算机程序预测出的干细胞寿命对实际干细胞寿命都有着惊人的准确性。 Dr. Muller-Sieburg and her colleagues found that stem cell self-renewal is strictly regulated to successfully negotiate a precarious balance: too much self-renewal results in leukemia, while too little leads to bone marrow failure. This new understanding now allows them to better predict the conditions that lead to normal stem cell proliferation. Muller-Sieburg博士及其同事发现干细胞自我更新一直在谨守着一个并不稳定的平衡:更新太频 繁，可能会导致白血病发生;更新太少，可能会导致骨髓衰竭。这种对干细胞的新认识使得 Muller-Sieburg博士和她的团队能更好的对干细胞维系正常增殖的条件进行预测。 Not only are these findings relevant to bone marrow transplants, they could also have implications for regenerative medicine. The safety and efficacy of using embryonic and other stem cells for tissue regeneration will depend on harnessing and precisely controlling their proliferative capacity. By providing a better understanding of how stem cells proliferate, and when they die, this lifespan prediction program could help improve their therapeutic potential for diabetes, Alzheimer's disease and other conditions. 这些发现不仅有助于骨髓移植，也会对再生医学产生一定的影响，因为用胚胎干细胞或其它干细 胞进行的组织再生的安全性和有效性，依赖于对这些干细胞的增殖能力的驾驭和精确控制。借助 于对干细胞增殖行为和死亡时间的更好理解，这种干细胞寿命预测程序可以提高干细胞对糖尿 病、阿尔兹默症和其它一些疾病治疗的潜力。 Mathematical modeling has other benefits, too. According to lead author Hans Sieburg, Dr. rer. nat, "Computer simulation allows us to generate a hypothesis, make predictions about what should be true, and then better plan our experiments in a way that requires fewer animal experiments." 此外，数学模型还有其它好处，正如文章第一作者Hans Sieburg, 博士指出的，“计算机模拟可 以让我们提出假设，对真实的情况进行预测，然后可以更好的实验，从而减少实验动物的使 用。”。 干细胞能存活多久, 《科学日报》2011年3月4日报导-患者接受骨髓移植手术后，可获得一群新的造血干细胞。这 种新的造血干细胞适用于贫血等红细胞性偏低以及癌症或癌症放化疗导致的白细胞偏低等情况 的治疗。然而这类干细胞移植面临的问题是:移植的干细胞可能存活不久而导致骨髓移植失败， 或者这类细胞可能增殖分化异常导致白血病发生。 为帮助确定骨髓(干细胞)移植物的存活时间，桑福德-伯纳姆医学研究所(桑福德伯纳姆)的 研究人员最近开发了一种用于预测干细胞存活时间的数学模型，并在大鼠模型中对这种模型的预 测效果进行了评价。这项研究是由Christa MSieburg博士负责的，研究结果2月28日在线发表 在Proceedings of the National Academy of Sciences杂志上。 桑福德-伯纳姆干细胞和再生生物学项目教授，Muller-Sieburg博士评论说:“长久以来，人们一 直认为干细胞是不会死亡的，它们在人的一生中可以不停的自我更新，不断产生更多的干细胞。 但是我们现在发现每个干细胞其实都只是在一定的时间范围内能够按照预定的流程进行自我更 新，对于小鼠，这个时间范围从几个月到几年不等。因此，我们建立一个计算机程序来预测干细 胞的生存时间”。 研究人员抽取了受移植小鼠的血液，对移植产生的成熟白细胞进行了一些初步测定，并将这些参 数输入计算机程序进行干细胞寿命的预测，然后将预测出干细胞寿命和干细胞的实际寿命进行比 较。一些干细胞的寿命在5个月左右，另一些则超过3年，采用前面描述的方法进行了多次比较，令人惊奇的是，每次计算机程序预测出的干细胞寿命对实际干细胞寿命都有着惊人的准确性。 Muller-Sieburg博士及其同事发现干细胞自我更新一直在谨守着一个并不稳定的平衡:更新太频繁，可能会导致白血病发生;更新太少，可能会导致骨髓衰竭。这种对干细胞的新认识使得Muller-Sieburg博士和她的团队能更好的对干细胞维系正常增殖的条件进行预测。 这些发现不仅有助于骨髓移植，也会对再生医学产生一定的影响，因为用胚胎干细胞或其它干细胞进行的组织再生的安全性和有效性，依赖于对这些干细胞的增殖能力的驾驭和精确控制。借助于对干细胞增殖行为和死亡时间的更好理解，这种干细胞寿命预测程序可以提高干细胞对糖尿病、阿尔兹默症和其它一些疾病治疗的潜力。 此外，数学模型还有其它好处，正如文章第一作者Hans Sieburg, 博士指出的，“计算机模拟可以让我们提出假设，对真实的情况进行预测，然后可以更好的设计实验，从而减少实验动物的使用。”。