Lab
Torsten Falk's Lab
Institution: The University of Arizona
About the lab
The Lab research research focuses on cellular and rodent models to test 1) novel pharmacological treatments for levodopa-induced dyskinesias, a major side effect of Parkinson’s disease treatment, 2) novel neuroprotective (growth factor mediated) gene therapy approaches to Parkinson’s disease, and 3) Development of glycopeptides for the treatment of Parkinson’s disease.
Featured research (14)
Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) is a pleiotropic peptide known to promote many beneficial processes following neural damage and cell death after stroke. Despite PACAP’s known neurotrophic and anti-inflammatory properties, it has not realized its translational potential due to a poor pharmacokinetic profile (non-linear PK/PD), and limited Blood-Brain Barrier Penetration (BBB) permeability. We have previously
shown that glycosylation of PACAP increases stability and enhances BBB penetration. In addition, our prior studies showed reduced neuronal cell death and neuroinflammation in models of Parkinson’s disease and Traumatic Brain Injury (TBI). In this study we show that a PACAP(1 2 7) glucoside retains the known neuro-
trophic activity of native PACAP(1 2 7) in vitro and a 5-day daily treatment regimen (100 nM) leads to neurite-like extensions in PC12 cells. In addition, we show that intraperitoneal injection of a PACAP(1 2 7) lactoside (10 mg/kg) with improved BBB-penetration, given 1-hour after reperfusion in a Transient Middle Cerebral Artery Occlusion (tMCAO) mouse model, reduces the infarct size after the ischemic injury in males significantly by ~ 36 %, and the data suggest a dose-dependency. In conclusion, our data support further development of PACAP glycopeptides as promising novel drug candidates for the treatment of stroke, an area with an urgent clinical need.
Levels of the opioid peptide dynorphin, an endogenous ligand selective for kappa-opioid receptors (KORs), its mRNA and pro-peptide precursors are differentially dysregulated in Parkinson’s disease (PD) and following the development of L-DOPA-induced dyskinesia (LID). It remains unclear whether these alterations contribute to the pathophysiological mechanisms underlying PD motor impairment and the subsequent development of LID, or whether they are part of compensatory mechanisms. We sought to investigate nor-BNI, a KOR antagonist, 1) in the dopamine (DA)-depleted PD state, 2) during the development phase of LID, and 3) via measuring of tonic levels of striatal DA. While nor-BNI (3 mg/kg; s.c. ) did not lead to functional restoration in the DA-depleted state, it affected the dose-dependent development of abnormal voluntary movements (AIMs) in response to escalating doses of L-DOPA in a rat PD model with a moderate striatal 6-hydroxdopamine (6-OHDA) lesion. We tested five escalating doses of L-DOPA (6, 12, 24, 48, 72 mg/kg; i.p. ), and nor-BNI significantly increased the development of AIMs at the 12 and 24 mg/kg L-DOPA doses. However, after reaching the 72 mg/kg L-DOPA, AIMs were not significantly different between control and nor-BNI groups. In summary, while blocking KORs significantly increased the rate of development of LID induced by chronic, escalating doses of L-DOPA in a moderate-lesioned rat PD model, it did not contribute further once the overall severity of LID was established. While we observed an increase of tonic DA levels in the moderately lesioned dorsolateral striatum, there was no tonic DA change following administration of nor-BNI.
Lab head
Department
- Department of Neurology and Department of Pharmacology
About Torsten Falk
- Dr. Falk's research focuses on rodent models to test 1) novel pharmacological therapies for L-DOPA-induced dyskinesias, a major side effect of Parkinson’s disease (PD) treatment, 2) neuroprotective approaches to treat PD, and 3) development of glycopeptides for the treatment of neurodegeneration. Dr. Falk is the author of > 40 peer-reviewed journal publications, holds two patents, is co-founder of Teleport Pharmaceuticals, LLC, and on Review Panels for the Parkinson’s Foundation and NIH/NINDS.