Transcriptome deregulation of peripheral monocytes and whole blood in GBA-related Parkinson's disease.

BACKGROUND: Genetic mutations in beta-glucocerebrosidase (GBA) represent the major genetic risk factor for Parkinson's disease (PD). GBA participates in both the endo-lysosomal pathway and the immune response, two important mechanisms involved in the pathogenesis of PD. However, modifiers of GBA penetrance have not yet been fully elucidated. METHODS: We characterized the transcriptomic profiles of circulating monocytes in a population of patients with PD and healthy controls (CTRL) with and without GBA variants (n = 23 PD/GBA, 13 CTRL/GBA, 56 PD, 66 CTRL) and whole blood (n = 616 PD, 362 CTRL, 127 PD/GBA, 165 CTRL/GBA). Differential expression analysis, pathway enrichment analysis, and outlier detection were performed. Ultrastructural characterization of isolated CD14+ monocytes in the four groups was also performed through electron microscopy. RESULTS: We observed hundreds of differentially expressed genes and dysregulated pathways when comparing manifesting and non-manifesting GBA mutation carriers. Specifically, when compared to idiopathic PD, PD/GBA showed dysregulation in genes involved in alpha-synuclein degradation, aging and amyloid processing. Gene-based outlier analysis confirmed the involvement of lysosomal, membrane trafficking, and mitochondrial processing in manifesting compared to non-manifesting GBA-carriers, as also observed at the ultrastructural levels. Transcriptomic results were only partially replicated in an independent cohort of whole blood samples, suggesting cell-type specific changes. CONCLUSIONS: Overall, our transcriptomic analysis of primary monocytes identified gene targets and biological processes that can help in understanding the pathogenic mechanisms associated with GBA mutations in the context of PD.

Dysregulation of mitochondrial and proteolysosomal genes in Parkinson's disease myeloid cells.

An increasing number of identified Parkinson's disease (PD) risk loci contain genes highly expressed in innate immune cells, yet their role in pathology is not understood. We hypothesize that PD susceptibility genes modulate disease risk by influencing gene expression within immune cells. To address this, we have generated transcriptomic profiles of monocytes from 230 individuals with sporadic PD and healthy subjects. We observed a dysregulation of mitochondrial and proteasomal pathways. We also generated transcriptomic profiles of primary microglia from brains of 55 subjects and observed discordant transcriptomic signatures of mitochondrial genes in PD monocytes and microglia. We further identified 17 PD susceptibility genes whose expression, relative to each risk allele, is altered in monocytes. These findings reveal widespread transcriptomic alterations in PD monocytes, with some being distinct from microglia, and facilitate efforts to understand the roles of myeloid cells in PD as well as the development of biomarkers.

Synthesis and pharmacological analysis of a morphine/substance P chimeric molecule with full analgesic potency in morphine-tolerant rats.

BACKGROUND: We have previously explored the functional role of the tachykinin substance P (SP) in the mediation of opioid-dependent antinociception and now describe the formulation, synthesis, and initial pharmacological characterization of a hybrid chimeric molecule, designated MSP9, containing the mu opioid receptor (MOR) agonist morphine covalently attached through a succinic acid linker to the SP receptor (SPR) agonist domain SP3-11. MATERIAL/METHODS: Pharmacological characterization of MSP9, administered by the intramuscular route, was achieved in naive and morphine-tolerant male rats utilizing the tail-flick test. RESULTS: MSP9 produced significant antinociceptive responses across a wide concentration range and displayed an atypical bell-shaped analgesic dose response relationship with peak effect of 40+/-10% reached at 0.2 mg/kg. The antinociceptive responses achieved by very low concentrations of MSP9 were not obtained by administration of equivalent low doses of morphine, suggesting that kinetic and dynamic parameters may contribute to its unusual analgesic properties. Importantly, MSP9 produces a strong antinociceptive response when administered to morphine-tolerant rats, suggesting a significant activation of kappa and/or delta receptors (KORs and DORs, respectively) in the presence of functionally down regulated MORs. CONCLUSIONS: Analyses employing selective, blood brain barrier (BBB) permeable, opioid and SP antagonists administered alone or in combination, indicate an obligate requirement for coincident activation of populations of CNS opioid and SP receptors. These combined data suggest that MSP9 activates multiple opioid- and SPR-expressing systems functionally linked to CNS analgesic responses, designating this class of hybrid chimeric molecules as prime candidates for therapeutic development for a wide range of clinical indications.