Diagnostic Monitor: The Cunningham lab has discovered methods to monitor central and peripheral nervous system neuronal damage resulting from an increase in the inflammatory enzyme secreted phospholipase A2 (sPLA2).  These methods can be used to monitor the progress of neurological diseases and neuroinflammatory damage.  Phospholipase A2 enzymes have been demonstrated to be involved in the genesis of behavior deficits and inflammation in animal models of multiple sclerosis.  While the exact etiology of multiple sclerosis is unknown, autoimmune inflammatory reactions are upregulated.  There is no cure for multiple sclerosis or other neurological disorders, only therapies to alleviate symptoms of the disease and to decelerate disease progression.  Exploring different modes of neuronal protection may be advantageous in drug design.

Therapeutic: The Cunningham lab has discovered 9-mer and 7-mer CHEC peptides that are novel potential anti-inflammation therapeutics by inhibiting sPLA2.  The peptides stimulate protein repair by activating heat shock protein 70 (HSP 70).  Elevated levels of sPLA2 enzymes and the resulting biochemical signaling cascade that occurs upon this elevation have been implicated in the pathology of several neurological diseases, including multiple sclerosis, amyotrophic lateral sclerosis, spinal cord injury, traumatic brain injury, and systemic inflammation.  sPLA2 enzymes are attractive therapeutic targets because of their accessibility in circulation, as well as their connection to inflammatory and cell death mechanisms.  Protein aggregate diseases, including Alzheimer’s and Parkinson’s, could also be impacted by these peptides.

Modifications of the cell survival and anti-inflammatory peptide CHEC-9 have been synthesized and tested in vivo.  The CHEC-9 peptide is a mimetic of DSEP (diffusible survival evasion peptide), a neuro-cyto protective polypeptide that inhibits inflammatory cells.  This peptide has been shown to reduce the spinal cord pathology of multiple sclerosis in an animal model.  The peptide protected nerve cells after injection into animal models of other neurodegenerative disorders, such as for ALS. The peptide also stimulates protein disaggregation in in vitro, ex vivo, and in vivo models.

One modification of CHEC-9, termed CHEC-7, has two fewer hydrophobic amino acids and may have greater cell uptake and higher therapeutic efficacy than CHEC-9.  A single subcutaneous injection of CHEC-7 in a rat model inhibited the acute rise of plasma sPLA2 activity and provided a more prolonged inhibition of sPLA2 activity than that of CHEC-9.

On the diagnostic side, urine samples from several dozen multiple sclerosis patients were analyzed, and these patients had elevated levels of sPLA2 enzymes compared to healthy patients.  The sPLA2 level correlated to ongoing disease activity, with the average enzyme activity higher in relapsing patients compared to stable patients.  A colorimetric test strip has been developed, whereby the hydrolysis of the phosphatidylcholine substrate of sPLA2 triggers a reaction with colloidal gold, producing a color change in about five minutes.  This test strip allows for an easy measurement to determine the occurrence of this inflammatory marker and whether relapse is imminent.  Patients with other disorders characterized by inflammatory flare-ups, including asthma, rheumatoid arthritis, Crohn’s disease, psoriasis, and lupus may benefit from this diagnostic assay.