Myelin-producing Brain Cells Regenerated Using Stem Cells in Early Study

Researchers, using two different kinds of stem cells in rats, were able to regenerate oligodendrocytes — myelin-producing brain cells that are defective in multiple sclerosis (MS). They were also able to grow adult neural stem cells in laboratory cultures and prod them to develop into oligodendrocytes. The exact cause of MS is unknown — including what triggers attacks on myelin — but the loss of oligodendrocytes seen in the disease is known to play a role in its progression. Nerve cells in the brain send their signals through their axons, long arm-like structures that extend out from the centers of the nerve cells. The signals are electrical pulses transmitted along the length of an axon. Oligodendrocytes provide the insulation — called myelin — that wraps around axons, speeding up the transmission of electrical signals through the nerve cells. Loss or malfunction of oligodendrocytes means that signaling in the brain is impaired. It is this slowing of signaling that is thought to cause MS symptoms. Researchers from the Heinrich-Heine-University, Germany, with support from British and Chilean colleagues, designed a novel approach to regenerate oligodendrocytes, according to a press release. Stem cells are immature cells that give rise to differentiated cells — cells with a specific function, such as oligodendrocytes. Adult neural stem cells can divide and produce nerve cells and other brain cells, including oligodendrocytes. However, in normal circumstances, the regeneration of cells that take place in the human brain is not enough to repair the damage seen in MS. The researchers set out to find conditions that would promote the differentiation of adult human NSCs into oligodendrocytes. They discovered that another type of stem cell, mesenchymal stem cells (MSCs), could provide the signals required. First they tested their system in rats, and found that by using factors produced by human MSCs, they could induce the growth of new oligodendrocytes in the animals. Then they grew adult NSCs in the laboratory, and using the same factors from human MSCs were able to promote the establishment of oligodendrocytes in the cultured cells.

Antidepressant Luvox Promotes Production of Neuron-protecting Sheath in Rats, Study Shows

A new study on rats indicates that the antidepressant Luvox promotes the production of the neuron-protecting coating that is deficient in multiple sclerosis. It also significantly decreased the severity of the animals' disease, researchers said, adding that Luvox promoted the production of the protective coating by helping stem cells evolve into oligodendrocytes, or cells that generate what is known as the myelin sheath. Patients with MS often experience anxiety and depression, with recent studies suggesting their rate of depression is three times higher than those with other long-term medical conditions. In addition to drugs targeting the underlying mechanisms of MS, such as inflammation and myelin loss, doctors often recommend that patients take antidepressants. The most common treatments they prescribe for moderate or severe depression are a class of serotonin re-uptake inhibitors that include Luvox. Few studies have looked at antidepressants' effects on animal models of MS, however. That prompted researchers to investigate Luvox's impact on both laboratory and rat models of the disease. Researchers used embryonic neural stem cells in their study. Luvox prompted laboratory stem cells to evolve into other types of cells, including neurons, oligodendrocytes, and astrocytes, which have several roles, including supporting and repairing neurons. Prozac also promoted stem cell differentiation — but at levels 10 times higher than those of Luvox. A key finding was that that Luvox significantly decreased the severity of the disease in the rats. Another important finding was that Luvox significantly reduced demyelination and immune cell infiltration in the rats' spinal cords. It also decreased the rats' expression of pro-inflammatory proteins known as cytokines. Overall, this study “demonstrated that fluvoxamine, in addition to its confirmed role in mood disorder therapy, could serve as a candidate clinical treatment for attenuating [reducing] neuro-inflammation and stimulating oligodendrogenesis in neurological diseases, particularly MS patients.”