# Proteomic Analysis of Thin Filament Components Elucidates Changes in Spastic Muscle Sarcomere After Stroke

## TL;DR

This study investigates how stroke affects muscle proteins in spastic muscles, identifying specific changes in thin filament proteins over time.

## Contribution

The study provides new insights into the proteomic changes in spastic muscle sarcomeres following a stroke.

## Key findings

- Significant changes in cytoskeletal protein expressions were observed in stroke-affected gastrocnemius muscles.
- Proteomic analysis revealed specific upregulated and downregulated proteins in thin filaments at different post-stroke time points.
- Altered proteins may contribute to changes in spastic muscle sarcomere structure after stroke.

## Abstract

This study analyzed the changes in the composition of thin filaments in spastic muscles after stroke to investigate the mechanism underlying changes in the sarcomeres. Twenty-four rats were randomly divided into four groups: normal, and 3, 6, and 9 days after stroke. A model of post-stroke gastrocnemius muscle spasm was created. Quantitative proteomic procedure and bioinformatics analysis revealed significant changes in cytoskeletal protein expressions in gastrocnemius muscles of each stroke group, particularly those on thin filaments. On the 3rd day after stroke, proteins upregulated within the thin filaments included actin-binding LIM protein 1, tropomyosin 3, leiomodin 2, drebrin-like protein, parvin beta, capping actin protein-gelsolin like, actinin alpha 2, and PDZ-LIM-domain protein 1, while downregulated proteins included tropomyosin 1, gelsolin, actinin alpha 3, and PDZ-LIM-domain protein 7. On the sixth day, upregulation of tropomyosin 2 was newly added while parvin alpha, destrin, PDZ-LIM-domain protein 3, leiomodin 3 were downregulated. On the 9th day, actinin alpha 2, PDZ-LIM-domain protein 7, and cofilin 2 were downregulated. These altered proteins are capable of promoting actin filament elongation and regulating Z-disc growth, and changes in their expression may be responsible for the changes in spastic muscle sarcomere after stroke.