Dual ankyrinG and subpial autoantibodies in a man with well-controlled HIV infection with steroid-responsive meningoencephalitis: A case report.

Neuroinvasive infection is the most common cause of meningoencephalitis in people living with human immunodeficiency virus (HIV), but autoimmune etiologies have been reported. We present the case of a 51-year-old man living with HIV infection with steroid-responsive meningoencephalitis whose comprehensive pathogen testing was non-diagnostic. Subsequent tissue-based immunofluorescence with acute-phase cerebrospinal fluid revealed anti-neural antibodies localizing to the axon initial segment (AIS), the node of Ranvier (NoR), and the subpial space.

Axon Initial Segments Are Required for Efficient Motor Neuron Axon Regeneration and Functional Recovery of Synapses.

The axon initial segment (AIS) generates action potentials and maintains neuronal polarity by regulating the differential trafficking and distribution of proteins, transport vesicles, and organelles. Injury and disease can disrupt the AIS, and the subsequent loss of clustered ion channels and polarity mechanisms may alter neuronal excitability and function. However, the impact of AIS disruption on axon regeneration after injury is unknown.

βIV-Spectrin Autoantibodies in 2 Individuals With Neuropathy of Possible Paraneoplastic Origin: A Case Series.

Objective: To identify the autoantigen in 2 individuals with possible seronegative paraneoplastic neuropathy.

Methods: Serum and CSF were screened by tissue-based assay and panned for candidate autoantibodies by phage display immunoprecipitation sequencing (PhIP-Seq). The candidate antigen was validated by immunostaining knockout tissue and HEK 293T cell-based assay.

Ankyrin-dependent Na channel clustering prevents neuromuscular synapse fatigue.

Skeletal muscle contraction depends on activation of clustered acetylcholine receptors (AchRs) and muscle-specific Na channels (Nav1.4). Some Nav1.

Ankyrin-R regulates fast-spiking interneuron excitability through perineuronal nets and Kv3.1b K channels.

Neuronal ankyrins cluster and link membrane proteins to the actin and spectrin-based cytoskeleton. Among the three vertebrate ankyrins, little is known about neuronal Ankyrin-R (AnkR). We report AnkR is highly enriched in Pv fast-spiking interneurons in mouse and human.

Spectrins.

Lindsay Teliska and Matthew Rasband introduce spectrins - cytoskeletal proteins that localise to the inner face of the plasma membrane and serve a scaffolding function between membrane proteins and the actin cortex.

Nodal β spectrins are required to maintain Na channel clustering and axon integrity.

Clustered ion channels at nodes of Ranvier are critical for fast action potential propagation in myelinated axons. Axon-glia interactions converge on ankyrin and spectrin cytoskeletal proteins to cluster nodal Na channels during development. However, how nodal ion channel clusters are maintained is poorly understood.