Arimoclomol is a small molecule that upregulates "molecular chaperones" in cells under stress. Arimoclomol extends survival by five weeks when given both pre-symptomatically and at disease onset in a mutant superoxide dismutase (SOD1) transgenic mouse model of ALS. Furthermore, it has been demonstrated to have neuroprotective and neuroregenerative effects in other rat models of nerve damage. Molecular chaperone proteins are critical in the cellular response to stress and protein misfolding. Recent data suggest that the SOD1 mutation responsible for ALS in some patients with familial disease reduces the availability of a variety of molecular chaperones, and thus weakens their ability to respond to cellular stress. Protein misfolding and consequent aggregation may play a role in the pathogenesis of both the familial and sporadic forms of ALS. Therapeutic agents such as arimoclomol that improve cellular chaperone response to protein misfolding may be helpful in ALS.
