Proteomic analysis of Substantia nigra proteins in STZ-induced Type-II diabetic rats: A possible link with Parkinson’s disease

Abstract

Type-II diabetes mellitus (TIIDM) is a metabolic disorder characterized by high level of glucose in blood due to high secretion of glucose from peripheral tissues, low secretion of insulin or dysfunction of insulin. Parkinson’s disease (PD) is a neurodegenerative disorder characterized by loss of Dopamine in the Substantia nigra of midbrain leading to cause motor dysfunction in affected people. TIIDM and PD have associations with each other as the individuals suffering from TIIDM are at more risk to develop PD in old age. The present study has analyzed eight (08) differentially expressed proteins in the Substantia nigra of TIIDM rat’s brain by using Nano-LC-MS/MS method. Nano-LC-MS/MS is highly recommended technique for the identification & quantification of proteins. RPS27a, PSMC1, PSMa4, ATP8, ATP5f1d and CALM3 were down-regulated while PSMa3 and PRKACa were up-regulated in rat’s brain. These differentially regulated proteins were further analyzed and found to be involved in the oxidative stress, mitochondrial dysfunction, Dopamine pathway, dysfunctional insulin signaling pathway, Ubiquitin regulatory pathways, and Ca²⁺ signaling pathways of both TIIDM and PD. In conclusion, the current study proposed a link between TIIDM and PD through primary estimated involvement of these proteins in both disorders. However, more in-depth molecular and proteomics studies are needed to be carried out for the possible expression of current proteins as target in the treatment and or prevention of PD in TIIDM patients.