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Iron is widely linked with the onset and development of Parkinson's disease (PD). Accumulation of iron induces free radical generation and promotes α-synuclein aggregation, oxidative stress, and autophagy impairment. Deferoxamine, an iron chelator, is shown to ameliorate iron dyshomeostasis in rodents and humans. However, the role of deferoxamine in cypermethrin-induced iron accumulation is not yet known. Although an iron accumulation and impaired chaperone-mediated autophagy (CMA) contribute to PD, a link between the two is not yet widely understood. Current study is undertaken to explore the possible association between an iron accumulation and CMA in cypermethrin model of PD in the presence of deferoxamine. Level of iron, iron transporter proteins, oxidative stress, and CMA proteins along with indicators of Parkinsonism were measured. Deferoxamine attenuated cypermethrin-induced iron accumulation and number of iron-positive cells and ameliorated the demise of dopaminergic cells and dopamine content. Deferoxamine significantly normalizes cypermethrin-induced changes in iron transporter proteins, α-synuclein, lysosome-associated membrane protein-2A, and oxidative stress. The results demonstrate that deferoxamine ameliorates cypermethrin-induced iron dyshomeostasis and impairment in CMA. [ABSTRACT FROM AUTHOR]

The etiology of Parkinson's disease (PD) is highly complex and is still indefinable. However, a number of studies have indicated the involvement of pesticides and transition metals. Copper, magnesium, iron, and zinc have emerged as important metal contributors. Exposure to pesticides causes an accumulation of transition metals in the substantia nigra (SN) region of the brain. The cypermethrin model of PD is characterized by mitochondrial dysfunction, autophagy impairment, oxidative stress, etc. However, the effect of cypermethrin on metal homeostasis is not yet explored. The study was designed to delineate the role of metals and their transporter proteins in cypermethrin-induced animal and cellular models of PD. The level of copper, magnesium, iron, and zinc was checked in the nigrostriatal tissue and serum by atomic absorption spectroscopy. Since cypermethrin consistently increased iron content in the nigrostriatal tissue and serum after 12 weeks of exposure, the level of iron transporter proteins, such as divalent metal transporter-1 (DMT-1), ceruloplasmin, transferrin, ferroportin, and hepcidin, and their in silico interaction with cypermethrin were checked. 3,3′-Diaminobenzidine-enhanced Perl's staining showed an elevated number of iron-positive cells in the SN of cypermethrin-treated rats. Molecular docking studies revealed a strong binding affinity between cypermethrin and iron transporter protein receptors of humans and rats. Furthermore, cypermethrin increased the expression of DMT-1 and hepcidin while reducing the expression of transferrin, ceruloplasmin, and ferroportin in the nigrostriatal tissue and human neuroblastoma cells. These observations suggest that cypermethrin alters the expression of iron transporter proteins leading to iron dyshomeostasis, which could contribute to dopaminergic neurotoxicity. [ABSTRACT FROM AUTHOR]

Microgliosis and inflammation are major wrongdoers in cypermethrin-induced Parkinsonism along with oxidative stress, mitochondrial dysfunction and α-synuclein aggregation. Dopamine depletion could alter dendritic morphology, length and spine number in the striatum. Present study investigated the effect of ibuprofen on the dendritic morphology, length and spine density in cypermethrin PD model. Male pups were treated intraperitoneally with cypermethrin during postnatal days followed by adulthood to induce Parkinsonism using standard procedure along with controls. Subsets of animals were pre-treated with ibuprofen 2 h prior to cypermethrin treatment during adulthood. Standard methods were used to confirm Parkinsonism/neuroprotection. Striatal dendritic morphology, length, spine number and expression of synaptophysin and postsynaptic density protein-95 (PSD-95) along with the nigrostriatal pro-inflammatory and apoptotic proteins were measured. Cypermethrin induced Parkinsonian traits and attenuated the dendritic length, spine number and expression of synaptophysin and PSD-95. While cypermethrin increased the expression of interleukin-1β, interleukin-4, interferon-γ, inducible nitric oxide synthase, caspase-3, caspase-9 and B-cell lymphoma (Bcl)-xl proteins, it attenuated Bcl-2 expression. Ibuprofen normalized the changes in dendritic morphology, length, spine number and expression of synaptophysin, PSD-95, and pro-inflammatory and apoptotic proteins. Results demonstrate that cypermethrin induces inflammation and alters dendritic morphology, length and spine number, which are encountered by ibuprofen. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is the second most familiar, progressive and movement-related neurodegenerative disorder after Alzheimer disease. This study aimed to decipher the role of autophagy in cypermethrin-induced Parkinsonism, an animal model of PD. Indicators of autophagy [expression of beclin 1, autophagy-related protein 12 (Atg 12), unc-51 like autophagy activating kinase 1 (Ulk 1), p62 and lysosome-associated membrane protein 2 (LAMP 2) and conversion of microtubule-associated protein 1A/1B-light chain 3 (LC3) I to II], signalling cascade [phosphorylated (p) 5′ adenosine monophosphate-activated protein kinase (p-AMPK), sirtuin 1 (Sirt 1), phosphorylated-mammalian target of rapamycin (p-mTOR), tuberous sclerosis complex 2 (TSC 2), pUlk 1 and pUlk 1 levels] and lysosome morphology were assessed in control and cypermethrin-treated rat model of PD. Autophagy markers were also measured in cypermethrin-treated neuroblastoma cells in the presence of 3-methyl adenine, a phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) class III inhibitor; vinblastine, an autophagosome elongation inhibitor; bafilomycin A1, an autophagolysosome and lysosome fusion/abnormal acidification inhibitor or torin 1, a mechanistic target of rapamycin inhibitor. Cypermethrin reduced LAMP 2 and increased p-AMPK and Sirt 1 without causing any change in other signalling proteins. 3-Methyl adenine did not change LC3 conversion; vinblastine and bafilomycin A1 decreased LAMP 2 expression in controls. While cypermethrin increased LC3 conversion in the presence of 3-methyl adenine, LAMP 2 reduction was more pronounced in vinblastine and bafilomycin A1-treated cells. Torin 1 normalized the expression of LAMP 2 without any change in other autophagy markers. Results demonstrate that albeit cypermethrin activates autophagosome formation, it reduces LAMP 2 expression and lysosome quality leading to autophagy inhibition. [ABSTRACT FROM AUTHOR]