Human Amyotrophic Lateral Sclerosis iPSC Model
Amyotrophic lateral sclerosis, ALS, also called Lou Gehrig's Disease, is a fatal, late-onset disease with severe diagnosis and no cure today. ALS targets motor neurons, causing their loss and eventually, the damage of motor function muscle movement. ALS occurs as a bulbar or spinal ALS.
ALS is a rare disease with no clear etiology. 10% of patients have a familial hereditary form of ALS - familial ALS, fALS -, but most of the patients, 90%, suffer from sporadic ALS. Sporadic and familial forms are clinically identical.
Familial Forms, SOD1, C9ORF72, and TDP43, of Amyotrophic Lateral Sclerosis
Familial ALS is caused by mutations of C9ORF72, SOD1, TDP43, and others.
The mutations C9ORF72, SOD1, and TDP43 cover different pathological mechanisms of ALS so that phenotypic assays with mutated iPSC-derived motor neurons will gain their predictive power.
The C9ORF72 gene is implicated in ALS through the repetition of GGGGCCG expansion in non-coding regions with effects on RNA binding and autophagy regulation.
The mutations of SOD1 affect the enzyme Cu/Zn-superoxide dismutase 1. These mutations cause the degeneration of motor neurons by oxidative stress, protein aggregates, mitochondrial defects, and glutamate excitotoxicity.
The TAR DNA-binding protein 43 (TDP-43) is another mutation that causes fALS. The misfolded protein TDP43 contributes to motor neuron death. It is supposed that SOD1 mutation and misfolding of TDP43 are related.
Neurodegenerative mechanisms in ALS are very diverse, which explains the difficulties of developing new treatments for this disease. NeuroProof, therefore, offers different ALS iPSC derived disease models for testing treatments in different disease mechanisms.
iPSC Derived Motor Neuron Cells with SOD1, and C9ORF72 Mutation, and Healthy Control Neuronal Activity
We present the neuronal activity for the three human motor neuron cell lines cultivated on microelectrode arrays. These motor neurons form spontaneous activity patterns, see here.
Both mutated cell lines with the SOD1 and the C9ORF72 mutation reveal disturbed excitatory-inhibitory balance, E/I balance. In particular, iPSC derived motoneuron cultures with a SOD1, or a C9ORF72 mutation shows a hyper-excitation in comparison to the healthy control as described above.
Image: Spike train parameter comparison of a SOD1-D90A cell-line, its isogenic control, and a C9orf72 cell line, demonstrating a highly hyper-excited activity pattern of the ALS mutated cell-lines.
Description of an Example with a SOD1-D90A mutation ALS Rescue Assay
As an example, we illustrate a rescue assay that rescues the electrical activity pattern of a mutated SOD1 iPSC derived motor neuron cell line back to a healthy phenotype, here the activity of ist isogenic control cell line. We recorded the spike train data at day 11 in vitro,
Spike train parameters were calculated with NeuroProofs proprietary spike train analysis tools. With a specific projection of the spike train parameters into a one-dimensional effect-score, it is then possible to assess the putative therapeutic effect of a compound.
Image: Example of a compound effect in an ALS rescue assay. It is assessed the reversion of a compound from the diseased cell line normalized at one to the healthy cell line normalized at zero.
NeuroProof is a drug screening CRO offering new functional phenotypic screening assays for new potential disease-modifying treatments of ALS.
The functional phenotypic readouts of the MEA recordings can be supplemented by further readouts, as detection of TDP-43 aggregates or a survival assay.
NeuroProof is continuously expanding its assay portfolio, ask us for potential new ALS cell lines with familial or sporadic forms. NeuroProof performs integrated projects from sourcing of diseased cell lines, cell differentiation, assay development to compound screening campaigns.