טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentGolko Sagit
SubjectNovel Therapeutic Approach of the Protective Multi-Target
Iron Chelating Compound Combined with Enriched
Diet in Mouse Model of Amyotrophic
Lateral Sclerosis
DepartmentDepartment of Medicine
Supervisors Professor Emeritus Moussa Youdim
Dr. Orly Weinreb
Full Thesis textFull thesis text - English Version


Abstract

Amyotrophic Lateral Sclerosis (ALS) is a multifactorial disease that arises from a combination of several pathologies that act through concurring damage inside motor neurons and muscles, including: mitochondrial dysfunction, oxidative stress, transitional metal accumulation, apoptosis and decreased supply of trophic factors. These multiple disease etiologies implicated in ALS gave rise to the perception that future therapeutic approaches for the disease should be aimed at targeting multiple pathological pathways.

   Based on this, our research group have designed and synthesized a series of multitarget, nontoxic, brain permeable iron chelators with potent monoamine oxidase (MAO) inhibitory activity, by chemically hybridizing the N-propargyl moiety of the antiparkinsonian drug rasagiline (Azilect?), into the 8- hydroxyquinoline skeleton of the iron chelator, VK-28. Among these compounds, M30 and VAR10303 (VAR) were previously shown to exert iron-chelating potency, antioxidant properties and inhibition of MAO-A and MAO-B activities in several preclinical models of neurodegeneration.

In the current study, we have considered to optimize the neuroprotective/neurorestorative abilities of M30 and VAR, by using combination treatment of our drugs with high calorie/energy supplemented diet (ced) in SOD1G93A transgenic ALS mice

   We have demonstrated that combined administration of low dose of M30-ced, started before the appearance of disease symptoms, exerted additive protective effects: delayed the progression in motor deficits, increased survival of SOD1G93A mice, inhibited MAO-A and -B activities and decreased the turnover of striatal dopamine in  SOD1G93A mouse.  

Treatment of VAR-ced, initiated after the appearance of the disease symptoms,  provided several beneficial rescue effects in ALS SOD1G93A mice, including delaying the progression in motor deficits, elevation of survival, preventing iron accumulation, motoneuron loss and neuromuscular junction denervation (NMJ) in the gastrocnemius (GNS) muscle in drug-treated, compared to vehicle-treated SOD1G93A mice.

Moreover, VAR-ced treated SOD1G93A mice had a significant preservation of myofibril regular morphology associated with a reduction in expression levels of genes related  to denervation (AChR-α and -γ, MuSK) and atrophy (MuRF1 and Atg-1) in GNS muscle. These effects were accompanied by up-regulation of mitochondrial DNA and activities of complexes I and II (NADH and succinate dehydrogenase enzymes) in GNS muscle of SOD1G93A mice.

   We also demonstrated that VAR-ced treatment up-regulated the mitochondrial biogenesis master regulator, peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α) and PGC-1α-targeted metabolic genes and proteins, such as, PPARγ, UCP1/3, NRF1/2, Tfam, and ERRα in GNS muscle of SOD1G93A mice.

   Furthermore, VAR-ced treatment increased the expression of the hypoxia inducible factor 1α (HIF-1α) and HIF-target protective genes encoded to glycolytic enzymes  and enhanced the anti-apoptotic index of the mitochondrial proteins Bcl-2/Bax, the expression levels of the neurotrophic factors, BDNF and GDNF and the phosphorylation rate of Akt and GSK-3β in GNS muscle and frontal cortex of SOD1G93A mice.

   In addition, VAR administration showed cytoprotective/antioxidant effects and attenuated loss of mitochondrial membrane potential/mass in H2O2-induced C2C12 myoblasts.

These results suggest that the overall protective effects of M30- and VAR-ced treatments, can synergistically help to buffer impaired mitochondrial intracellular energy store, mainly of muscular origin in SOD1G93A mice, and thus may suggest as novel beneficial treatment of ALS.