Journal: BMC Pharmacology & Toxicology
Article Title: Human in vitro neuromuscular junction model to functionally dissect the pathogenic mechanism of anti-AChR autoantibody-positive myasthenia gravis
doi: 10.1186/s40360-025-01056-1
Figure Lengend Snippet: 3D compartmentalised design of human neuromuscular tissues on a microfluidic device. ( A ) The fabricated NeuroMuscle TM device uses the PDMS inlet microchannel to form a single NMJ microfluidic device, each composed of a muscle compartment with muscle fibre attaching pillar structures and the MN spheroids compartment. The muscle compartment has two medium reservoirs on each side. The MN compartment has a single medium reservoir. ( B ) Photo of the 3D NeuroMuscle TM microstructure. ( C ) Human iPSCs were seeded on an AggreWell™800 plate at Day 0 and MN spheroids were generated at Day 7. GCaMP6-transduced human skeletal myoblasts were injected into the muscle compartment of the NeuroMuscle TM device at day 0. Spontaneous self-organisation of myoblast into muscle bundle was observed after Day 5. A MN spheroid was introduced into the neuronal compartment and embedded in collagen gel. Thin neurite outgrowth was observed at Day 15 and many thick nerve bundles reached the muscle tissue at day 18, resulting in the formation of NMJs. Scale bars, 500 µm. ( D ) Differentiation of MN spheroids were characterised by the immunostaining of Tuj1, HB9, SMI-32, and VGLUT1. The pattern of a sarcomere structure stained by sarcomeric α-actinin and titin. SMI-32 staining showed that neurites from the motor neuron innervated muscle cells. AChR clusters are labelled with α-bungarotoxin (BTX; monochrome) and indicated by white arrows. Scale bars, 200 µm. ( E ) Schematic illustration of the differentiation and co-culture of the MN spheroid and muscle cells in a NeuroMuscle TM device. 3D, three-dimensional; AChR, acetylcholine receptor; BTX, α-bungarotoxin; D, day; DAPI, 4’,6-diamidino-2-phenylindole; GCaMP6, genetically encoded calcium indicator protein 6; iPSC, induced pluripotent stem cell; MN, motor neuron; NMJ, neuromuscular junction; PDMS, polydimethylsiloxane; SAA, serum amyloid a; Tuj1, class III beta-tubulin; VGLUT1, vesicular glutamate transporter 1
Article Snippet: Subsequently, the samples were incubated overnight with primary antibodies against class III beta-tubulin (1:200; Abcam, Cambridge, UK), HB9 (1:50; Santa Cruz, Dallas, TX, USA), SMI-32 (1:100; BioLegend, San Diego, CA, USA), vesicular glutamate transporter 1 (VGLUT1) (1:100; Abcam), sarcomeric α-actinin (1:100; Abcam), titin (1:200; Developmental Studies Hybridoma Bank, Iowa City, IA, USA), and C5b9 (1:500; BD Biosciences, Franklin Lakes, NJ, USA) in the blocking buffer.
Techniques: Generated, Injection, Immunostaining, Staining, Co-Culture Assay