astrocytes

Bit.bio launches human astrocyte product to help model brain

Bit.bio, a company that creates human-derived cell products, has launched a novel product called ioAstrocytes, which provides functional human astrocytes to help scientists model the brain and study neurological disease mechanisms or screen new drugs. Astrocytes are star-shaped cells in the brain and spinal cord that provide support…

Therapeutic Target for Inflammation Driven by Astrocytes Seen

Using a new approach, researchers have identified new signaling molecules that regulate the activation of certain subsets of astrocytes thought to drive inflammation in multiple sclerosis (MS). The new methodology, called FIND-seq, enables the selection of single cells from a sample based on the expression of specific genes and…

Oligodendrocyte Precursor Cells Disrupt Blood-brain Barrier, Trigger Brain Inflammation in MS, Study Shows

Oligodendrocyte precursor cells (OPCs), the cells responsible for myelin production, are unable to migrate into sites of myelin loss in the brain. These cells then cluster and disrupt the blood-brain barrier (BBB), triggering an inflammatory process in the early stages of multiple sclerosis (MS), a study shows. The study, “Aberrant oligodendroglial–vascular interactions disrupt the blood–brain barrier, triggering CNS inflammation,” was published in the journal Nature Neuroscience. MS is an autoimmune disease characterized by the loss of myelin (demyelination) — the fat-rich substance that protects nerve fibers — which leads to neurodegeneration. Along with loss of myelin, researchers have observed that the blood-brain barrier — a highly selective membrane that shields the central nervous system with its cerebrospinal fluid from the general blood circulation — breaks down in the initial stages of disease. A team led by researchers at the University of California, San Francisco, have now discovered that OPCs are involved in the disruption of the blood-brain barrier in MS, according to a press release from the National MS Society, which funded the study. Oligodendrocytes are myelin-producing cells and are responsible for myelinating the nerve cells’ axons — a single oligodendrocyte is capable of myelinating multiple axons. Mature myelin-producing oligodendrocytes develop from more immature, stem cell-like OPCs. In a normal brain, upon myelin loss, OPCs are called into action and travel into the damage site where they mature and generate myelin-producing oligodendrocytes. In this study, the researchers found that OPCs in MS form clusters in blood vessels of the brain-blood barrier, having lost the ability to detach from these vessels and migrate to injury sites. In an animal model of MS, they saw that OPC aggregates altered the location of other cells — called astrocytes — in a competition for space, and contributed to the disruption of blood vessels. Astrocytes are a group of star-shaped cells, belonging to the group of glial cells, that provide neurons with energy, and work as a platform to clean up their waste. They also have other functions within the brain, such as regulating blood flow and inflammation. The team also observed that OPC aggregates trigger an immune inflammatory response, shown by a large number of microglia (the central nervous system immune cells) and immune cells called macrophages around these cell clusters. “We find in several MS cases, in lesion areas with active inflammation, that OPCs can be found clustered on vasculature, representing a defect in single cell perivascular migration and inability to detach from blood vessels,” the researchers wrote. Further molecular analysis revealed that OPCs have high levels of Wnt signaling, and elevated secretion of Wif1 factor to the extracellular space that could explain why OPCs accumulate and destroy the blood-brain barrier. The WiF1 factor is actually a negative regulator of Wnt signaling that is essential for the maintenance of the blood-brain barrier structure. This factor competes with Wnt ligands, and affects the integrity of cellular junctions, making the blood-brain barrier more fragile and permeable. "Evidence for this defective oligodendroglial–vascular interaction in MS suggests that aberrant OPC perivascular migration not only impairs their lesion recruitment but can also act as a disease perpetuator via disruption of the BBB,” the researchers wrote. They suggested that more studies are needed to better understand the interactions between blood vessels and oligodendrocytes, which could help identify new therapeutic targets for promoting myelin repair in MS.

Need to Know: What Is Remyelination?

Editor’s note: “Need to Know” is a series inspired by common forum questions and comments from readers. Have a comment or question about MS? Visit our forum. This week’s question is inspired by the forum topic “New MS Therapy Company to Focus on Rejuvenating Coating…

New Way of Growing Astrocytes from Stem Cells May Aid Research into Brain Disorders Like MS

Researchers at The Salk Institute have developed a way to grow vital brain cells called astrocytes from stem cells, a potential breakthrough for basic and clinical research into several diseases, including multiple sclerosis (MS). The study “Differentiation of Inflammation-responsive Astrocytes from Glial Progenitors Generated from Human Induced Pluripotent…

Gilenya Could Help Treat SPMS by Countering Astrocytes, Study Says

Gilenya (fingolimod) a multiple sclerosis (MS) drug developed to target the immune system and control inflammation, can also reduce the negative action of astrocytes, further controlling inflammation, says a new study. The article, “Sphingosine 1-Phosphate Receptor Modulation Suppresses Pathogenic Astrocyte Activation and Chronic Progressive CNS Inflammation,” appeared in the…

Astrocytes Can Turn Aggressive and Kill Neurons, Potentially Groundbreaking Study Says

In what may be one of the most significant discoveries in neurodegenerative disease, researchers have found that brain cells, called astrocytes, contribute to killing neurons and myelin-forming oligodendrocyte cells, which may drive neurodegenerative diseases such as multiple sclerosis (MS). Experiments indicate an aggressive astrocyte type kills cells by secreting a yet-unidentified…