# Label-free morphology-based phenotypic analysis of spinal and bulbar muscular atrophy muscle cell models

## TL;DR

This study introduces a noninvasive method to screen drugs for spinal and bulbar muscular atrophy using muscle cell morphology.

## Contribution

A novel morphology-based phenotypic analysis method for SBMA drug screening using machine learning.

## Key findings

- Morphological profiling successfully assessed therapeutic effects of drugs on SBMA muscle cells.
- The JNK pathway was activated in SBMA cells compared to controls.
- A machine learning model accurately classified drug responses based on morphological profiles.

## Abstract

Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disorder caused by CAG trinucleotide expansion in the androgen receptor (AR) gene. To improve the quality of in vitro cell-based assays for the evaluation of potential drug candidates for SBMA, we developed a morphology-based phenotypic analysis for a muscle cell model of SBMA that involves multiparametric morphological profiling to quantitatively assess the therapeutic effects of drugs on muscle cell phenotype. The analysis was validated using dihydrotestosterone and pioglitazone, which have been shown to exacerbate and ameliorate the pathophysiology of SBMA, respectively. Gene expression analysis revealed activation of the JNK pathway in the SBMA cells compared to the control cells. Phenotypic analysis revealed the effect of naratriptan, a JNK inhibitor, on the phenotypic changes of SBMA cells, and the results were confirmed by LDH assays. We then trained a predictive machine learning model to classify the drug responses, and it successfully discriminated between pioglitazone-type and naratriptan-type morphological profiles based on their morphological characteristics. Our morphology-based phenotypic analysis provides a noninvasive and efficient screening method to accelerate the development of therapeutics for SBMA.

Summary: This study established a noninvasive and efficient in vitro drug screening technique based on morphology-based phenotypic analysis using a muscle cell model of spinal and bulbar muscular atrophy.