Research

New Progress in Stem Cell Culture Technique

I. Cell Stem Cell: Development of a method for long-term culture of adult stem cells in vitro

doi: 10.1016/j.stem.2016.05.012

In a new study, researchers from Massachusetts General Hospital (MGH) and other institutions have developed a new method that could revolutionize the field of adult stem cell culture. The researchers describe obtaining and multiplying airway stem cells from various tissue samples collected during routine treatments for lung disease. This approach also appears to work with several other tissues, such as the skin, the lining of the gastrointestinal tract, and the reproductive tract. The related research results were published online in the journal Cell Stem Cell on June 16, 2016, with the title of "Dual SMAD Signaling Inhibition Enables Long-Term Expansion of Diverse Epithelial Basal Cells".

"This new method opens up new avenues for studying any kind of airway disease, such as asthma or chronic obstructive pulmonary disease (COPD)," said senior author Jayaraj, a scientist at the MGH Center for Regenerative Medicine and an associate professor of medicine at Harvard Medical School. Dr. Rajagopal said, "Although we were only able to allow adult stem cells to proliferate for a few generations in the past, today we can grow enough adult stem cells for several years in multiple laboratories for experiments. Our method is also very simple, avoiding The complexity of previous culture systems has been removed, making it easier for many labs to adopt it."

II. Nat Commun: Three kinds of stem cell manufacturing technologies proved to be safe

doi: 10.1038/ncomms10536

In a new study, researchers from several institutions, including The Scripps Research Institute (TSRI) and the J. Craig Venter Institute (JCVI), confirmed that Methods of making pluripotent stem cells for clinical use are unlikely to pass oncogene mutations to patients. The related research results were published in the journal Nature Communications on February 19, 2016, with the title "Whole-genome mutational burden analysis of three pluripotency induction methods". This study is an important step in evaluating the safety of rapidly developing stem cell therapies for patients.

The new study focused on the safety of using induced pluripotent stem cells (iPSCs) in patients. Because iPSCs can differentiate into any type of cell in the body, they have the potential to repair damage caused by abrasions or diseases such as Parkinson's disease and multiple sclerosis.

"We wanted to know if reprogramming cells made them susceptible to mutations," said Jeanne Loring, TSRI professor of developmental neurobiology who led the new study with Professor Nicholas J. Schork, director of the Division of Human Biology at JCVI. "The answer is no ."

III. Nature: Help! Scientists discover new way to grow blood stem cells

DOI: 10.1038/nature17665

In a major advance in understanding stem cells in the human blood system, researchers at McMaster University's Stem Cell and Cancer Research Institute have discovered how a key protein allows these cells to better control and regeneration.

The study, recently published in the journal Nature, sheds light on how a protein called Musashi-2 regulates the function and development of important hematopoietic stem cells.

The findings provide new strategies that can be used to control the growth of these stem cells. These cells are used to treat a range of deadly diseases, but are often in very short supply.

Study senior author Kristin Hope is a principal investigator at the Stem Cell and Cancer Institute and an assistant professor in the Department of Biochemistry and Biomedical Sciences at McMaster University. Other collaborators include researchers from the University of California, San Diego, the University of Toronto and the University of Montreal.

Hope said the discovery could have profound implications for thousands of patients suffering from a range of blood disorders, including leukemia, lymphoma, aplastic anemia, sickle cell disease and more.

IV. PNAS: Scientists develop the first adult induced pluripotent stem cells

On April 4, a research team from the University of New South Wales (UNSW) published an article in the top journal PNAS, developing a revolutionary stem cell repair technology for the first time. The technology can successfully re-induce fat and bone cells into multipotent stem cells, and is expected to be used in the treatment of human injuries including spinal injuries and fractures.

This technology is similar to salamander limb regeneration. Its most prominent achievement is that it converts adult cells into induced multipotent stem cells (iMS cells), and iMS cells have the function of self-renewal and differentiation into various types of cells. This iMS cell can treat human body damage caused by disease, aging or trauma, which will revolutionize the status quo of regenerative medicine in the treatment of body damage.

The first induced multipotent adult stem cells (iMS): capable of self-renewal, repair, and differentiation into multiple cell types.

According to the stage of development, stem cells can be divided into embryonic stem cells (ES cells, which have the ability to differentiate into complete individuals) and adult stem cells (somaticstem cells). Adult stem cells have the function of differentiating into specific cells and cannot differentiate into a variety of cell types. The breakthrough of the latest technology published by PNAS is that induced pluripotent stem cells can differentiate into multiple types of cells.

V: PNAS: Adult adipocytes can differentiate into pluripotent stem cells, or can be used for tissue damage repair

For the first time, Australian scientists have obtained stem cells that can differentiate into any tissue by reprogramming adult bone or fat cells to repair damaged tissues and organs in the body.

Inspired by the phenomenon that "lizards can regenerate their limbs", these researchers developed a technology that can return adult cells to a stem cell state and acquire the potential for division and multidirectional differentiation -- pluripotent stem cells. This means that these cells can repair damage anywhere in the body: from spinal cord, joint, and muscle degeneration, to name a few. The significance of this study is that there has never been a report of successfully differentiating adult stem cells into multiple types of tissues before.

"This technology is a revolutionary advance in the field of stem cell therapy, where there has never been evidence that adult stem cells can directly differentiate into tissues." Lead researcher John Pimanda, from the University of New South Wales, said. "We are currently studying how adult adipocytes can be reprogrammed into induced pluripotent stem cells to repair tissue damage in mice. It is expected to enter clinical trials in 2017."

VI: Nature: A major breakthrough! Human haploid embryonic stem cells are produced for the first time!

doi: 10.1038/nature17408

In a new study, researchers from the Hebrew University of Jerusalem in Israel, Columbia University Medical Center in the United States, and the Stem Cell Foundation Institute in New York have succeeded in generating a new type of embryonic stem cell that carries only a single copy of the human genome, instead of the two copies of the human genome normally found in normal stem cells. The related research results were published online in the journal Nature on March 16, 2016, with the title of "Derivation and differentiation of haploid human embryonic stem cells".

The haploid embryonic stem cells described in this study are the first known capable of cell division to produce human daughter cells that carry a single copy of the parent cell's genome.

Human cells are considered diploid because they inherit two sets of chromosomes for a total of 46 chromosomes, 23 from the mother and 23 from the father. The only exceptions are germ cells (egg and sperm), which are haploid cells and contain one set of chromosomes, 23 chromosomes. These haploid cells cannot divide to produce more eggs and sperm.

Previous efforts to generate embryonic stem cells from human egg cells have resulted in the generation of diploid stem cells. In this study, the researchers promoted the division of unfertilized human egg cells. They then labelled the DNA with a fluorescent dye and isolated these haploid embryonic stem cells, where they were scattered among more diploid cells.