UCLA researchers have reprogrammed human induced pluripotent stem cells

For the first time, UCLA researchers have reprogrammed human induced pluripotent stem (iPS) cells into the cells that finally become eggs and sperm, possibly opening the door for new treatments for sterility using patient-specific cel

The iPS cells were coaxed into forming germ line precursor cells which include genetic material that may be passed on to a child. The study appears today in the early online edition of the peer-reviewed journal Stem Cells.
“This finding could be important for people who are rendered infertile through disease or injury. We may, one day, be able to replace the germ cells that are lost,” said Amander Clark, a Broad Stem Cell Research Center scientist and senior author of the study. “And these germ cells would be specific and genetically related to that patient.”
Theoretically, an infertile patient’s skin cells, for example, could be taken and reprogrammed into iPS cells, which, like embryonic stem cells, have the ability to become every cell type in the human body. Those cells could then be transformed into germ line precursor cells that would eventually become eggs and sperm. Clark cautioned, however, that scientists are still many years from using these cells in patients to treat infertility. There is still much to be learned about the process of making high quality germ cells in the lab.In another important finding, Clark’s team discovered that the germ line cells generated from human iPS cells were not the same as the germ line cells derived from human embryonic stem cells. Certain vital regulatory processes were not performed correctly in the human iPS derived germ cells, said Clark, an assistant professor of molecular, cell and developmental biology.
So it’s crucial, Clark contends, that work continue on the more controversial human embryonic stem cells that come from donated, excess material from in vitro fertilization that would otherwise be destroyed.
When germ cells are formed, they need to undergo a specific series of biological processes, an essential one being the regulation of imprinted genes. This is required for the germ cells to function correctly. If these processes are not performed the resulting eggs or sperm, are at high risk for not working as they should. This has significant consequences, given that the desired outcome is a healthy child.
“Further research is needed to determine if germ line cells derived from iPS cells, particularly those which have not been created by retroviral integration, have the ability to correctly regulate themselves like the cells derived from human embryonic stem cells do,” Clark said. “When we looked at the germ cells derived from embryonic stem cells, we found that they regulated as expected, whereas those from the iPS cells were not regulated in the same way. We need to do much more work on this to find out why.”

Humanitarian goals, science get new life

PRESIDENT Obama's inauguration has led to the resumption of aid to international groups that perform or give information about abortions and should open the door to important scientific research. Both developments are a boost to humanitarian and medical advances that should expand during the Obama administration.
The new president signed an executive order on Friday that ended the ban on giving taxpayer money to international family groups that offer abortions or provide related information. The assistance was available from the Agency for International Development during the Clinton administration but banned during the Reagan and both Bush administrations.
Obama also is expected to restore funding for the U.N. Population Fund, which George W. Bush had rejected on the contention that it supported a Chinese family planning policy of coercive abortion and involuntary sterilization, an allegation that the agency vehemently denied. In fact, the lifting of the bans will reduce unintended pregnancies, abortions and the deaths of women from high-risk pregnancies.
The signing came a day after the Food and Drug Administration allowed the world's first clinical trial of a treatment derived from human embryonic stem cells for spinal cord injury. The therapy uses an old embryonic stem cell line that was allowed under the latest Bush administration but the approval might have been delayed until Bush left office.
The Bush administration restricted federal financing for embryonic stem cell research because creation of the cells entailed destruction of human embryos, even though they had been destined for the trash. President Obama has pledged to remove some of the financial restrictions.

Flow cytometric analysis of Stem and Lineage Cell Markers

Research on stem cells is the subject of intense investigation, both from a basic science point of view, as well as a basis for cell-based therapies to treat disease. The ability to study and characterize stem cells has been aided by the identification of specific markers which allow researchers to characterize and enrich these cells. The use of immunophenotyping is an important technique to distinguish one population of cells from another. eBioscience is dedicated to providing you with a choice of innovative primary antibody reagents and flurochromes to accelerate your stem cell research using multicolor flow cytometry.

Brain's messengers could be regulated, MIT researchers find

Potential for better understanding of schizophrenia
J. Troy Littleton, a professor in the Picower Institute for Learning and Memory at MIT, joins biology graduate student Sarah N. Huntwork in the lab. They have created the first genetically-engineered mutant--in this case a fruit fly--that produces no complexins (proteins that play a role in the release of neuro-transmitters) during cell-to-cell signaling

Researchers at MIT's Picower Institute for Learning and Memory have found that tiny, spontaneous releases of the brain's primary chemical messengers can be regulated, potentially giving scientists unprecedented control over how the brain is wired.

The work, reported in the Sept. 16 early online edition of Nature Neuroscience, could lead to a better understanding of neurological diseases like schizophrenia.

Sputtering electrical activity--like a firecracker's leftover sparks after a big bang--was long considered inconsequential background noise compared with the main cell-to-cell interactions underlying thought and memory.

But lead author J. Troy Littleton, Fred and Carole Middleton Associate Professor of Biology at MIT, and colleagues found that the miniscule events that follow a burst of electrical and chemical activity among neurons are far more important that previously thought. A breakdown in this molecular mechanism could be the culprit in schizophrenia and other neurological diseases, the authors reported.

Neurons communicate with one another through chemical junctions called synapses. Key to the system are complexins. These small proteins play a role in the release of the brain's chemical messengers, or neurotransmitters, during synaptic cell-to-cell signaling.

To figure out exactly how complexins work, Littleton created the first genetically engineered mutant--in this case, a fruit fly--that produces no complexins at all.

There are two sides to synaptic transmission--pre-synaptic and post-synaptic. When an electrical nerve impulse zaps the pre-synaptic side, it triggers lightning-fast events that release neurotransmitters. This activates the post-synaptic cell. Mission accomplished: The foundation of a memory is formed.

The neurotransmitters are like racehorses. They champ at the bit until they get the signal to dash toward the finish line. On the pre-synaptic side, small compartments, or vesicles, containing neurotransmitters are the starting block, and complexins are the gatekeepers that prevent the neurotransmitters from releasing prematurely.

After a big burst of electrical activity sends out a flood of neurotransmitters, a few vesicles still produce some neurotransmitter. The MIT work explains the molecular machinery behind these "minis," which can occur for a few minutes after the big event. Without complexin as a gatekeeper, minis occur unchecked, leading to massive rewiring and synaptic growth.

"This spontaneous release in the brain is not only important for signaling, it can trigger synaptic growth," Littleton said. "What's really exciting is that complexin's activity may be regulated. If we can regulate this machinery, we may be able to promote synaptic growth and potentially allow targeted rewiring in areas of the brain affected in various neurological diseases."

Littleton also holds an appointment in MIT's Department of Brain and Cognitive Sciences.

Biology graduate student Sarah N. Huntwork coauthored the Nature Neuroscience paper.

This work was supported by the National Institutes of Health and the Packard Foundation for Science and Engineering.