Biology subjects

Klyachko, V. A.

Publications and source records attributed to Klyachko, V. A..

3 recordsLinked to original sources

bioRxiv2026

Satellite Glial Cells Control Sensory Neuron Excitability via the Release of Fibulin-2

Pain remains a major clinical challenge, with current therapies often limited by low efficacy and adverse effects. While excitability of sensory neurons in the dorsal root ganglia (DRG) is central to pain signaling, accumulating evidence highlights the importance of non-neuronal cells in modulating neuronal activity. Here, we identify satellite glial cells (SGCs) as a source of Fibulin-2, an extracellular matrix glycoprotein with diverse roles in nervous system development and repair. Using SGC primary cultures and mass spectrometry, we demonstrate that Fibulin-2 is secreted by SGCs in part via extracellular vesicles. Electrophysiological assays reveal that application of recombinant Fibulin-2 to cultured sensory neurons reduces neuronal excitability by modulating Kv4-mediated currents. In vivo, loss of Fibulin-2 leads to reduced Kv4.2 and Kv4.3 expression and heightened mechanical, heat and cold sensitivity in mice. Our findings uncover a SGC-sensory neuron signaling mechanism modulating pain sensitivity, suggesting Fibulin-2 as a potential therapeutic target for pain management.

neuroscience↗

bioRxiv2025

Ketogenic diet dampens excitatory neurotransmission by shrinking synaptic vesicle pools

HIGHLIGHTSO_LIKD rewires gene expression in the hippocampus, particularly impacting synaptic genes. C_LIO_LIKD profoundly alters epigenetic modifications in the hippocampus. C_LIO_LIKD reduces excitatory synaptic gain and dampens integration of synaptic inputs. C_LIO_LIKD reduces the readily releasable vesicle pool in excitatory synapses. C_LI The ketogenic diet (KD) is a common dietary intervention for treating seizures in intractable childhood epilepsies and has been proposed to improve disease outcome in neurodegenerative disorders. Despite its clinical applications, we know little about how this diet impacts brain circuitry and neuronal function to elicit its protective effects. Here, we examined the impact of the KD on hippocampal function through integrative analysis of gene expression, epigenetics and neurotransmission. We found that KD induces profound transcriptional reprogramming of the hippocampus, including dampened expression of numerous synaptic genes. Through proteomic analysis of histone variants and post-translational modifications, we uncovered significant changes in activating and repressive histone marks in the hippocampus of KD mice. To determine how transcriptional rewiring of the hippocampus under KD impacts neurotransmission, we performed electrophysiological recordings of neurotransmission and synaptic dynamics at excitatory CA3-CA1 synapses. We found that KD diminishes synaptic gain and dampens short-term plasticity at excitatory synapses, resulting in reduced integration of synaptic inputs at the circuit level. Combining electrophysiology and electron microscopy, we determined that effects of KD in excitatory synapses are caused by a reduction in size of the readily releasable pool of synaptic vesicles, as well as the total vesicle pool. Our findings show that the ketogenic diet triggers synaptic remodeling in the hippocampus, driven by broad transcriptional and epigenetic changes that reduce synaptic vesicle pools and short-term plasticity at excitatory synapses ultimately dampening excitatory synaptic gain and integration at the circuit level. These synaptic adaptations may represent a major mechanism underlying the anti-epileptic effects of this diet.

neuroscience↗

bioRxiv2019

Fatty acid synthesis in satellite glial cell promotes regenerative growth in sensory neurons

Peripheral sensory neurons switch to a regenerative state after nerve injury to enable axon regeneration and functional recovery. Intrinsic mechanisms operating in sensory neurons are known to regulate nerve repair, but whether satellite glial cells (SGC), which completely envelop the neuronal soma, undergo injury-evoked transcriptional changes and contribute to nerve regeneration remains unexplored. This is largely due to the lack of molecular and genetic tools to study SGC. Using a single cell RNAseq approach to define the transcriptional profile of SGC in naive and injured conditions, we reveal that these cells are distinct from Schwann cells and share similarities with astrocytes. We find that nerve injury elicits gene expression changes in SGC, which are related to fatty acid synthesis and peroxisome proliferator-activated receptor (PPAR) signaling. Conditional deletion of Fatty acid synthase (Fasn), the committed enzyme in de novo fatty acid synthesis, in SGC, impairs axon regeneration. The PPAR agonist fenofibrate rescues the impaired axon regeneration in mice lacking Fasn in SGC, indicating that PPAR functions downstream of fatty acid synthesis in SGC to promote axon regeneration. These results identify fatty acid synthesis in SGC as a fundamental novel mechanism mediating axon regeneration in adult peripheral nerves. These results also highlight that the sensory neuron and its surrounding glial coat form a functional unit that orchestrates nerve repair.

neuroscience↗