Amyloid-Beta Peptides Trigger Premature Functional and Gene Expression Alterations in Human-Induced Neurons

Non-fibril form but not fibril form of human islet amyloid polypeptide 8-20 changes brain functions in mice

Whether fibril formation increases or decreases cytotoxicity remains unclear. Aggregation of human islet amyloid polypeptide (hIAPP), a pivotal regulator of glucose homeostasis, impairs the function and viability of pancreatic β cells. Evidence suggests that low-order oligomers of hIAPP are more toxic to β cells than fibril. However, it remains unclear whether non-fibril form of hIAPP specifically alters brain functions. This study produced fibril and non-fibril forms from a single hIAPP 8-20 peptide. The non-fibril form-injected mice showed changes in spontaneous motor activities, preference for location in the open field and social behavior. In contrast, the fibril-injected mice showed no changes in these behavioral tests. In line with the behavioral changes, the non-fibril form led to impaired neurite outgrowth of cultured neuron-like cells and the loss of neurons in the mouse hippocampus. These findings suggest that non-fibril form but not fibril form of hIAPP changes brain functions.

Single-Cell Sequencing Technology and Its Application in the Study of Central Nervous System Diseases

The mammalian central nervous system consists of a large number of cells, which contain not only different types of neurons, but also a large number of glial cells, such as astrocytes, oligodendrocytes, and microglia. These cells are capable of performing highly refined electrophysiological activities and providing the brain with functions such as nutritional support, information transmission and pathogen defense. The diversity of cell types and individual differences between cells have brought inspiration to the study of the mechanism of central nervous system diseases. In order to explore the role of different cells, a new technology, single-cell sequencing technology has emerged to perform specific analysis of high-throughput cell populations, and has been continuously developed. Single-cell sequencing technology can accurately analyze single-cell expression in mixed-cell populations and collect cells from different spatial locations, time stages and types. By using single-cell sequencing technology to compare gene expression profiles of normal and diseased cells, it is possible to discover cell subsets associated with specific diseases and their associated genes. Therefore, scientists can understand the development process, related functions and disease state of the nervous system from an unprecedented depth. In conclusion, single-cell sequencing technology provides a powerful technology for the discovery of novel therapeutic targets for central nervous system diseases.