جدیدترین اخبار در مورد سلول های بنیادی

بانی اولین گوسفند شبیه سازی شده مسیر تحقیقات خود را تغییر داد    

پدر دالی (اولین گوسفند شبیه سازی شده ) تصمیم گرفته است مسیر تحقیقات خود را در زمینه ی شبیه سازی ترک کند و تکنیک جدیدی را دنبال کند که دانشمندان زاپنی با استفاده از سلول های بنیادی ارائه کرده اند

اولین میکرو کبد انسان

با استفاده از یک فناوری جدید محققان

موفق شدند سلول های کبدی انسان را

در قالب توده های سلولی کوچک ارایش دهند ومدت شش هفته یک کبد واقعی در اندازه ی500 میکرو متر را به دست اورند .

سلول های بنیادی خون ساز

محققان امریکایی موفق شدند در موش های ازمایشگاهی سلول های بنیادی بزرگسال خون ساز را به سیستم ایمنی جدید تبدیل کنند که این کشف می تواند برای بیماران خود ایمنی یا بیماران مبتلا به بیماری های خونی زنتیکی بسیار مفید باشد

سلول های بزرگسال استفاده از

دو تیم تحقیقاتی امریکایی وزاپنی به طور مستقل موفق شدند به نتایج مشابهی در خصوص تبدیل سلول های فیبرو پلاست به سلول های بنیادی جنینی دست یابند

سلول های بنیادی از سلول های عادی پوست

محققان در پیشرفتی تازه سلول های معمولی پوست را به سلول هایی تبدیل کردند که هم شبیه به سلول های بنیادی جنینی هستند و هم مانند ان ها عمل می کنند .

منابع : خبرگزاری های مهر – ایسنا- ایسکا نیوز باشگاه خبر نگاران جوان و جام جم انلاین

Cell regeneration brings hope for diabetics

Mice can regenerate insulin-producing cells. 

Some cells in the adult pancreas can, in times of extreme stress, produce new insulin-secreting cells, researchers have found.

The findings, based on work performed in mice, open up a new approach to replacing insulin-secreting cells in patients with diabetes. They also address a raging controversy within the diabetes research community over whether such cells even exist.

“It’s a big discovery,” says Emmanuel Baetge, chief scientific officer of Novocell, a stem cell company based in San Diego, California who was not involved with the work. “I think this will heat up the whole field.”

The blood and heart are known to be supplied with new cells by adult stem cells capable of generating a fresh stock. If such regenerative stem cells existed in the pancreas, they could perhaps be harnessed to restock the supply of pancreatic ß cells, which in turn produce insulin. This could form the basis of treatment for patients with type 1 diabetes who have fewer ß cells.

At least, that was the hope. Researchers tried and failed repeatedly to find such cells in the pancreas. “Most people, including me, concluded that the pancreas was very different,” says Douglas Melton, a Harvard University stem-cell researcher in Cambridge, Massachusetts.

Limited options

Without regenerative stem cells, there seemed to be only two ways to generate new ß cells in diabetics: encourage whatever few ß cells the patient still has to divide; or programme embryonic stem cells to produce the needed cell type and inject those into the patient.

Unfortunately, ß cells are difficult to isolate and grow very slowly in culture, making it difficult to boost their numbers. Embryonic stem cells are easier to grow, but difficult to programme. “There, the challenge is how to tell them what to do,” says Melton. Researchers from Baetge’s group have come close: embryonic stem cells have been coaxed into forming ß cells¹, but these cells were only marginally sensitive to glucose so wouldn't be able to regulate insulin production in diabetics.

Harry Heimberg, a researcher at the Diabetes Research Center at Vrije University in Brussels, Belgium, and his colleagues instead continued the hunt for pancreatic stem cells.

A new hope

Researchers had previously looked for the specific stem cells by damaging the pancreas, watching new ß cells come into existence, and then tracing them back to source. This showed that the new ß cells were emerging simply from the division of existing ones.

Heimberg and his colleagues damaged mouse pancreases in a different way: by clamping the duct that drains digestive enzymes from the pancreas. This causes inflammation and a doubling of ß cell numbers. “If you think of your head as the pancreas and the neck as the duct, they grabbed the neck and choked it,” says Melton.

When the researchers investigated the new cells, they found a population expressing a protein normally found only in embryonic pancreatic cells; a sign that stem cells may be involved. When the researchers checked, these cells could generate new ß cells capable of responding to glucose. The results are reported this week in Cell ².

Sleeping beauties

The work shows that mice can replenish insulin-producing ß cells — at least when pushed. Technically, the cells may not meet all the requirements to be classified as adult stem cells — to prove that, the researchers will need to go on to show that the cells can also replenish themselves. But the cells may hold therapeutic promise regardless, says Baetge, who has been working with embryonic stem cells to make ß cells.

Stem cell: A stem cell is a cell from the embryo, fetus, or adult that has, under certain conditions, the ability to reproduce itself for long periods or, in the case of adult stem cells, throughout the life of the organism. It also can give rise to specialized cells that make up the tissues and organs of the body.

Transplantation Research:

Stem cells may hold the key to replacing cells lost in many devastating diseases.

 But, despite recent advances in transplantation sciences, there is a shortage of donor organs that makes it unlikely that the growing demand for lifesaving organ replacements will be fully met through organ donation strategies. For many diseases that shorten lives, there are no effective treatments but the goal is to find a way to replace what natural processes have taken away.

The use of stem cells to generate replacement tissues for treating neurological diseases is a major focus of research. Spinal cord injury, multiple sclerosis, Parkinson's disease, and Alzheimer's disease are among those diseases for which the concept of replacing destroyed / dysfunctional cells in the brain / spinal cord is a practical goal. Researchers have recently shown that human embryonic stem cells to be directly differentiated into cells that produce insulin.

Therapeutic Delivery Systems:

Stem cell-based therapies are a major area of investigation in cancer research. For many years, restoration of blood and immune system function has been used as a component in the care of cancer patients who have been treated with chemotherapeutic agents. Now, researchers are trying to devise more ways to use specialized cells derived from stem cells to target specific cancerous cells and directly deliver treatments that will destroy or modify them.