About 16,000 ailing Americans are yet to receive a liver transplant. But due to a shortage of aviable livers, it’s likely that fewer than 7,000 transplants was performed in 2013. In Japan, where the shortage is even worse, the number of people who are in need of new livers is 10 times as large as the number of deceased donors who could provide one.
That gap motivated stem cell biologist Takanori Takebe and his colleagues at the Department of Regenerative Medicine at Yokohama City University in Japan to find an alternate solution. This year they succeeded in generating mini-livers, or liver buds, from stem cells that were taken from human skin and reprogrammed to an embryonic state.Embryonic stem cells are also notable because they can easily morph into virtually any cell type in the body.
In the process of mixing with two other types of cells, the fabricated primitive liver cells comes together and organized themselves into three-dimensional structures, complete with blood vessels. In effect, Takebe’s team re-created the process through which a human embryo starts to form a functioning liver.
Transplanted into a mouse, the human liver buds, which is about 5 millimeters long, exhibited many functions of the mature organ, such as metabolizing sugars and drugs. After the scientists disabled the mouse’s own liver, the human buds could kept the animal alive for a minimum of two months.
A person with liver failure would require an infusion of “tens of thousands” of liver buds,-Takebe says.
Until the buds can be generated from the skin of each individual patient, recipients will have to rely on immune-suppressing drugs to avoid rejection, just as they would with the transplant of an entire organ. Replacement liver buds might be available to human patients in a decade or less.— Jeff Wheelwright.
Scientists are to grow spare parts of the human brain for fixing neurological injuries or defects, but recently they’ve used stem cells to create brain organoids, and also for the formations of cells that can mimic some of the brain’s regions. A team which was led by neuroscientist Jürgen Knoblich of Austria’s Institute of Molecular Biotechnology has developed the organoids to help them simulate disease.
In the production of the mini-brains, two types of stem cells were used,
embryonic cells and adult cells that had been reprogrammed to a starter state.The cells were placed into a culture, then after, suspended in a gel and stimulated by nutrients, all geared to enable the transforming into neurons like those found in the cortex.
According to Knoblich, The neurons literally “self-organized,” and formed three-dimensional structures about one-tenth of an inch in diameter after several weeks.
“When zoomed out and the whole is being looked at, it’s not a brain,” Knoblich says. “But the cultures is said to contain individual brain regions that may seem to have a functional relationship with one another.” And also, besides the dorsal cortex, researchers were able to grow, among other parts or regions, parts of the ventral forebrain, which makes neurons that connect to the cortex, and the choroid plexus, which generates spinal fluid.
Knoblich says- that organoids are good for the model development of the brain and also for the study of anything that causes a defect in development,” .
For example, by taking neural stem cells from a patient with schizophrenia, researchers might turn back the clock and track the onset of the condition in an organoid. Knowing how schizophrenia starts might help prevent it.— Jeff Wheelwright.
Well I know I shouldn’t be mistaking to say that mammalian skin cell with an egg cell was first fused by biologists in 1996 , cloning Dolly the sheep. I think this was the beginning of the race to make a human embryo the same way. The method which was called somatic cell nuclear transfer (SCNT), was made to replace the DNA in an egg cell’s nucleus with the genetic material from the nucleus of a skin cell, then after it tricks the egg cell to start dividing as if it had been fertilized with sperm.
Wow this must have been a good idea.
But another steeps of getting eggs to act like embryos turned out to be far more difficult in humans than in sheep. But during sine few years ago May 2013-14, that-
Shoukhrat Mitalipov of the Oregon Health and Science University finally made SCNT work in humans, through careful tweaking and fine-tuning based on experiments with more than 1,000 rhesus monkey eggs.
Making purpose-built tissues may be far in the future, because figuring out the exact recipes to turn cells into functioning bone, heart or spinal cord will take time. But Mitalipov’s triumph has big near-term benefits in giving researchers a new tool to understand all the details of how stem cells grow, divide and differentiate,- says Larry Goldstein, director of the University of California San Diego Stem Cell Program “It’s great science.” — Kat McGowan
