神经科学

The fatal motor neuron (MN) disease amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of the phrenic MNs (phMNs) controlling the activity of the diaphragm, leading to death by respiratory failure. Human experimental models to study phMNs are lacking, hindering the understanding of the mechanisms of phMN degeneration in ALS. Here, we describe a protocol to derive phrenic-like MNs from human induced pluripotent stem cells (hiPSC-phMNs) within 30 days. During spinal cord development, phMNs emerge from specific MN progenitors located in the dorsalmost MN progenitor (pMN) domain at cervical levels, under the control of a ventral-to-dorsal gradient of Sonic hedgehog (SHH) signaling and a rostro-caudal gradient of retinoic acid (RA). The method presented here uses optimized concentrations of RA and the SHH agonist purmorphamine, followed by fluorescence-activated cell sorting (FACS) of the resulting MN progenitor cells (MNPCs) based on a cell-surface protein (IGDCC3) enriched in hiPSC-phMNs. The resulting cultures are highly enriched in MNs expressing typical phMN markers. This protocol enables the generation of hiPSC-phMNs and is highly reproducible using several hiPSC lines, offering a disease-relevant system to study mechanisms of respiratory MN dysfunction. While the protocol has been validated in the context of ALS research, it can be adopted to study human phrenic MNs in other research fields where these neurons are of interest.

Müller cells, the major glial cells of the retina, play vital roles in maintaining redox homeostasis and retinal metabolism. An immortalized human Müller cell line (MIO-M1) is widely used as an in vitro model to study Müller cells’ function, but they may not be exactly the same as primarily cultured human Müller cells. The use of human primary Müller cells (huPMCs) in culture has been limited by the requirement for complicated culture systems or particular age ranges of donors. We have successfully grown huPMCs using our established protocol. The cell type was pure, and cultured cells expressed Müller cell-specific markers strongly. The cultured huPMCs were used for morphologic, metabolic, transcriptomic, and functional studies.

Graphic abstract:

Timeline for human primary Müller cell (huPMC) culture

The human olfactory mucosa is located in the middle and superior turbinates, and the septum of nasal cavity. Olfactory mucosa plays an important role in detection of odours and it is also the only nervous tissue that is exposed to the external environment. This property leads to easy access to the olfactory mucosa for achieving various researches. The lamina propria of olfactory mucosa consists of olfactory ensheathing cells (OECs) that cover the nerve fibers of olfactory. Here we describe a protocol for isolation of OECs from biopsy of human olfactory mucosa.

We here provide a detailed protocol for the isolation and culture of primary mouse sensory neurons. The cell bodies of sensory afferent pseudounipolar neurons are located in dorsal root ganglia (DRGs) along the vertebral column. Dissected mouse DRGs can be dissociated into single cells by enzymatic digestion to obtain primary cultures of mouse sensory neurons as performed in the studies reported by Khaminets et al. (2015).