Oral Treatment with d-RD2RD2 Impedes Early Disease Mechanisms in SOD1*G93A Transgenic Mice but Does Not Prolong Survival

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting upper and lower motor neurons, thus, progressing to complete muscle loss until the patient dies from respiratory arrest. The disease is not curable, and patients die approximately 2–5 years after diagnosis. Studying the underlying disease mechanisms to get access to new treatment options is, therefore, essential for patients’ benefit. However, so far, only three drugs that alleviate the symptoms have been approved by the U.S. Food and Drug Administration (FDA). A new drug candidate for the treatment of ALS is the all-d-enantiomeric peptide RD2RD2. In this study, we investigated the therapeutic effect of RD2RD2 in two setups. First, we analyzed disease progression and survival in 7 week-old B6.Cg-Tg(SOD1*G93A)1Gur/J mice. Second, we confirmed the result of the survival analysis in the B6SJL-Tg(SOD1*G93A)1Gur/J mouse line. Shortly before disease onset, the mice were treated daily with an oral dose of 50 mg/kg body weight. Treatment with RD2RD2 led to a delayed disease onset and reduced motor phenotype as shown using the SHIRPA test, the splay reflex test, and the pole test, but did not affect survival. In conclusion, RD2RD2 has the ability to delay the onset of symptoms.

Characteristics of Sensory Neuron Dysfunction in Amyotrophic Lateral Sclerosis (ALS): Potential for ALS Therapy

“…However, most cases are sporadic, with no known genetic cause [46]. While ALS is currently incurable, various treatment options are being studied to manage its symptoms and improve the quality of life of individuals with the disease [47][48][49]. These treatments include medications to manage muscle cramps and spasticity, assistive devices to aid mobility and communication, and multi-disciplinary care involving physical, occupational, and speech therapy.…”