Effects of Telmisartan, an AT1 receptor antagonist, on mitochondria-specific genes expression in a mouse MPTP model of Parkinsonism
Background: Mitochondrial dysfunction plays a crucial role in Parkinson’s disease (PD) pathogenesis. The present study was undertaken to investigate the effects of Telmisartan (TEL), an angiotensin II type 1 receptor (AT1R) blocker, on the mitochondria-specific genes expression in a mouse model of Parkinsonism. Materials and methods: Mice were divided into 5 groups with 6 in each; Group I received 0.5% CMC (control) + saline, Group II received 0.5% CMC + 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (positive control), Group III & IV received MPTP + TEL 3 and 10 mg/kg, p.o. respectively, Group V received TEL 10 mg/kg, p.o. (drug control). MPTP was given 80 mg/kg intraperitoneal in two divided doses (40 mg/kg 2 at 16 h time interval). Vehicle or TEL was administered 1 h before the MPTP injection. Motor function was assessed 48 h after the first dose of MPTP and animals were euthanized to collect brain. Results: Mice intoxicated with MPTP showed locomotor deficits and significant upregulation of -synuclein (-syn), downregulation of metastasis-associated protein 1 (MTA1), and Ubiquitin C-terminal hydrolase L1 (UCHL1) in the substantia nigra pars compacta (SNpc) and Striatum (STr) regions of brains. In addition, MPTP intoxication down-regulated mitochondria-specific genes such as DJ-1, PTEN-induced putative kinase 1 (PINK1), Parkin, enriched with leucine repeats kinase 2 (LRRK2) gene expfression. Pre-treatment with TEL restored locomotor functions and upregulated PINK1, Parkin, LRRK2, DJ-1, MTA1 and UCHL1. Conclusion: The present study evidences that TEL has the ability to improve mitochondrial functions in PD.
Parkinson’s disease; Telmisartan; Mitochondria; α-synuclein; PINK1; Parkin; DJ-1; LRRK2; MTA1; UCHL1
Mitochondrial dysfunction plays a crucial role in the Parkinson’s disease (PD) pathogenesis . Neurons are particularly vulnerable to mitochondrial dysfunction as they are highly dependent on Electron transport chain (ETC) for energy requirements . The first event in mitochondrial impairment in PD is the deficiency of Complex I in the ETC [3, 4]. Dopaminergic SNpc neurons are susceptible to oxidative stress as they have poorly myelinated long and thin axons . -synuclein (-syn), a presynaptic protein related to PD pathogenesis, was reported to aggregate within the mitochondria which causes cell death [6, 7, 8]. Deposition of Lewy bodies and Lewy neurites (composed of several proteins including -syn) were reported as early changes that occur before the degeneration of the SNpc and expression of clinical symptoms of Parkinsonism [9, 10, 11].
Renin angiotensin system (RAS) in brain play a crucial role in PD . Activation of angiotensin II type 1 receptor (AT1R) triggers inflammatory pathways which increase ROS leading to dopaminergic cell death [12, 13]. Telmisartan (TEL), a lipophilic antihypertensive drug exerts its neuroprotective activity by blocking AT1R in the brain. In our earlier investigations, we have reported its neuroprotective activity acute and chronic model of Parkinsonism in mouse models [14, 15]. Blockade of AT1R using losartan was shown to exert anti-inflammatory activity in MPTP intoxicated mice model of PD [16, 17] and antioxidant properties against 6-OHDA model . Recently, AT1R and AT2R have been discovered in brain mitochondrial outer and inner membrane, respectively . Alleviation of mitochondrial function was shown to decrease oxidative stress and reduced the incidences of apoptosis in various neurological disorders [20, 21, 22, 23].
Recent understandings of the existence of RAS components in mitochondrial structure, we proposed investigate whether AT1R antagonism modulates mitochondrial functions, particularly in PD. As a preliminary approach, the present experiment is designed to unravel the role of AT1R antagonism using TEL on the mitochondria-specific genes expression in a MPTP model of Parkinsonism in mice.
3. Materials and method
Male C57BL/6J mouse (18–22 g b. wt.) were obtained from CPCSEA approved breeder and acclimatized for 7 days before the treatment, with an ambient temperature of 22 3 C with 12 h light/12 h dark cycle. They were provided with the standard diet with purified water ad libitum.
3.2 Chemicals & reagents
Telmisartan API was received as a kind gift from Bal Pharma Limited, Bangalore, India. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and TRIzol reagent were purchased from Sigma Aldrich, USA. PCR master cycler gradient was procured from Genet Bio, Korea. All the chemicals used in the experiment were analytical grade.
3.3 Experimental design
Animals were grouped into 6 per group, where Group I (Control) received 0.5% CMC + Saline as a vehicle, Group II (Positive Control) received MPTP + Saline, and Group III (TEL LD) & Group IV (TEL HD) received TEL 3 and 10 mg/kg p.o. respectively + MPTP and Group V received TEL 10 mg/kg p.o. as drug control. Neurotoxin, MPTP was given 80 mg/kg intraperitoneal in two divided doses (40 mg/kg 2 at 16 h time interval) from the first dose. All the treatment of TEL and vehicle were administered 1 h before the MPTP (Fig. 1). The motor function test was performed after 48th h of the first dose of MPTP administration . After completion of the motor functions tests, animals were perfused with Phosphate Buffered Saline (PBS) intracardially. Further substantia nigra pars compacta (SNpc; ~ Bregma—3.16 mm, interaural 0.64 mm) and Striatum region (ST; Bregma—0.98 mm, interaural 4.78 mm)  was extracted from the mice brain.
3.4 Motor function test
3.4.1 Beam walk experiment
Beam walk test was done after the MPTP intoxication, to cross a narrow beam of 100 cm length connecting to an escape box . An aversive stimulus was created with an optimistic light (60 lux) above the beam to trigger the mice to a dark goal box on the other side of the beam. The mice were kept at the beginning of the beam after 48th h of the first exposure of MPTP injection. The time taken to reach the escape box on the other hand (sec), number of foot slip (s), and immobility period were noted. The observer was blinded to the treatment protocols.
3.4.2 Horizontal grid
Horizontal grid test was done as per Kim et al.  method with minor changes. The apparatus was made up of horizontal grid mesh (size 12 cm: with an opening of 0.5 cm) mounted approximately 20 cm above a surface, supporting against the falling. Animals were kept independently in the center of the horizontal grid apparatus and given support until it grabs the grid. Then the grid was upturned to monitor the hanging time. The observer was blinded to the treatment protocols.
3.4.3 Vertical grid
Vertical grid test was done to assess the motor function as per the method of Kim et al.  with minor modifications. The apparatus is made of an open box of size 8 55 5 cm and the vertically standing back side of the box was prepared of wire mesh, with an open front side covering the other four sides with black Plexiglas. Animals were kept individually in the apparatus at a height of 3 cm from the bottom, keeping the face upwards and allowed to climb down on the grid. Time to climb down the grid and immobility period were noted. The observer was blinded to the treatment protocols.
3.5 Reverse transcriptase PCR (RT-PCR) analysis
Reverse transcriptase-polymerase chain reaction (RT-PCR) was done to determine the level of mRNA expression of -syn, Parkin, MTA1, DJ-1, UCHL1, PINK1, and LRRK2. In brief, total RNA was extracted from SNpc and STr regions of mice brains using TRIzol Reagent (Sigma, USA). Followed by the process of homogenization, the tubes were kept for incubation for 10 min then centrifuged at 1,000 rpm for 5 min. An amount of 200 L chloroform was put into the supernatant, further incubated for 5 min at room temperature followed by centrifugation at 12,000 rpm for 20 min. Total RNA was precipitated by adding 500 L of isopropyl alcohol to the supernatant and centrifuged at 12,000 rpm for 15 min and incubated for period of 10 min. The pellet obtained after decanting the supernatant was further washed 3 times with 75% ethanol then centrifuged at 12,000 rpm for 15 min and allowed to air-dry the pellet. The pellet was resuspended in 20 L of RNase-free water and stored at a temperature of 80 C. In the next step, the isolated RNA was subjected to undergo reverse transcription and polymerization reaction to obtain cDNA using PCR master cycler gradient. Then, the cDNA was processed for electrophoresis at 80 V for 30 min. Finally, the gene expression was analyzed using the bands formed in agarose gel. An amount of 200 nanograms of RNA were used for RT-PCR according to the manufacturer’s instructions (Genet Bio, Korea). The primers used in the experiment are given in Table 1, the images were quantified by ImageJ software.
3.6 Data analysis
Data obtained in the experiment were expressed as mean standard error of the mean (SEM). One-way ANOVA followed by Tukey’s multiple comparisons as post hoc test was applied to analyse the mean differences between the experimental groups in GraphPad Prism 5.0 (San Diego, USA) software considering P 0.05 significant.
4.1 Effect of TEL in motor function in MPTP intoxicated mice
4.1.1 Beam walk test
MPTP intoxicated mice showed an increased immobility period and took a long time in crossing the narrow runway with more numbers of foot slips (P 0.01) when compared to the normal control group. No difference in foot slip was noted in the drug control and normal control mice. Pre-treatment with TEL at 3 mg/kg (P 0.05) and 10 mg/kg (P 0.01) decreased in the time taken in crossing, foot slips, and immobility periods, in a dose-dependent manner, when compared to MPTP intoxicated group (Fig. 2).
4.1.2 Horizontal grid test
MPTP intoxicated mice showed a longer wall hanging time (P 0.01) when compared to normal control. Pre-treatment with TEL has significantly reduced the hanging time at 3 mg/kg (P 0.05) and 10 mg/kg (P 0.01) in a dose-dependent manner when compared to MPTP intoxicated mice. Drug control and normal control groups showed no significant difference in hanging time (Fig. 3).
4.1.3 Vertical grid test
MPTP intoxicated mice took a longer time (P 0.01) to climb down and increased immobility period (P 0.01) in comparison to normal control animals. TEL pre-treatment at 10 mg/kg reduced the climb down time (P 0.05) as well as reduced the immobility (P 0.01) period significantly when compared to MPTP intoxicated mice. No significant difference was observed at the lower dose of TEL (3 mg/kg) in the immobility period while compared to Parkinsonism mice (Fig. 4).
4.2 Reverse transcriptase PCR (RT-PCR) analysis
4.2.1 SNpc region
Significant upregulations of -syn (P 0.01), downregulations of DJ-1 (P 0.01), LRRK2 (P 0.01), MTA1 (P 0.01), Parkin (P 0.01), PINK1 (P 0.01), UCHL1 (P 0.01) mRNA expressions were observed in vehicle treated MPTP mice when compared to control mice. Pre-treatment with TEL downregulated the -syn (P 0.01) and upregulated DJ-1 (P 0.01), LRRK2 (P 0.01), MTA1 (P 0.01), Parkin (P 0.01), PINK1 (P 0.01), UCHL1 (P 0.01) in MPTP intoxicated in SNpc region of mice.
4.2.2 STr region
Significant upregulations of -syn (P 0.01), downregulations of DJ-1 (P 0.05), LRRK2 (P 0.05), MTA1 (P 0.05), Parkin (P 0.05), PINK1 (P 0.05), UCHL1 (P 0.05) mRNA expressions were observed in vehicle-treated MPTP mice when compared to control mice. Pre-treatment with TEL downregulated the -syn (P 0.01) and upregulated DJ-1 (P 0.05), LRRK2 (P 0.05), MTA1 (P 0.05), Parkin (P 0.05), PINK1 (P 0.05), UCHL1 (P 0.05) in MPTP intoxicated in STr region of mice. However, there was no significant difference in mRNA expressions between the normal control and drug control groups (Fig. 5).
The current study adds further evidence on the neuroprotective role of AT1R antagonism and also new information on its ameliorative effects on mitochondria-specific genes expression in PD. Inhibition of Complex I of ETC was reported in PD patient’s brains [28, 29]. Neurotoxin MPTP produces PD-like conditions by inhibiting the Complex I. Recently, AT1R and AT2R (RAS) were identified on the mitochondrial surface and inner membrane, respectively [19, 30]. Activation of AT1R was shown to impair the mitochondrial functions via NAD(P)H mediated oxidative stress in the PD . In our early study, we have shown that TEL suppresses nitrosative stress and elicits neuroprotection in a mouse model of PD . However, to date, there is no evidence on the effects of AT1R antagonism on mitochondria-specific genes expression which plays a crucial role in oxidative stress, inflammatory responses, and apoptosis. Hence, in the present study we investigated the effects of TEL on the mitochondria-specific genes like PINK1, Parkin, LRRK2, DJ-1 which may serve as newer therapeutic target in the treatment of PD.
Knockout/mutation in PINK1 and Parkin proteins are linked with PD pathogenesis [33, 34, 35]. Parkin is selectively recruited by PINK1 to the outer membrane of the damaged mitochondria to promote mitophagy in PD . In the present study, pre-treatment with TEL upregulated the PINK1 and Parkin in MPTP intoxicated mice brains, which indicates that AT1R antagonism may support the PINK1-Parkin mediated mitophagy and in turn improving mitochondrial dynamics [37, 38].
Knockout/mutation (G2019S) in LRRK2 impair autophagy and aggregation of -syn [39, 40, 41, 42]. Pre-treatment with TEL upregulated LRRK2 which might be the possible reason for the observed down-regulation in -syn expression and this can be speculated to improve neuronal clearance of -syn by autophagy process. This indicates that up-regulation of mitochondria-specific gene-LRRK2 via central RAS modulation imparts neuroprotection in PD.
In physiological condition, -syn play a crucial role in the regulating the post-synaptic dopamine uptake [43, 44]. Another mitochondria-specific protein DJ-1 , which acts as an oxidative stress sensor and antioxidant  and its down-regulation is correlated to the increased aggregation of -syn via inhibiting the chaperone-mediated autophagy [47, 48]. UCHL1, an important component of the ubiquitin-proteasome system (UPS), and its down-regulation is linked to increased expression of -syn, confirming its direct link in PD [49, 50, 51]. TEL increased DJ-1 and UCHL1, which further indicates that restoration of the mitochondrial genomic profile imparted neuroprotection via improving -syn clearance, at least partly.
Finally, the upregulation of MTA1 expression is reported to increase dopamine synthesis  and its packaging and subsequent release of dopamine from neuronal vesicles through the upregulation of vesicular monoamine transporter-2 (VMAT2) [53, 54]. The improved motor function recorded in beam walk, horizontal grid, and vertical grid tests with TEL might be due to the increased dopamine levels which may be corroborated by increased expression of MTA1 and DJ-1 in PD mice. The current findings support that modulation of brain RAS function improves mitochondrial function and can impart neuroprotection in PD (Fig. 6).
In conclusion, modulation of central RAS, particularly AT1R antagonism improves mitochondrial functions and exerts neuroprotection in PD.
7. Author contributions
BR performed the study. GR, SV and SR analyzed the data. ST and AMM assisted the study. MME and SBC designed the study corrected and finalized the manuscript.
8. Ethics approval and consent to participate
Institutional animal ethical committee, Central animal house, JSS Academy of higher education and Research, Mysuru, Karnataka, India approved the study (JSSAHER/CPT/IAEC/016/2020).
BR acknowledges the Indian Council of Medical Research (ICMR), New Delhi, Govt. of India, for the Senior Research Fellowship.
This research received no external funding.
11. Conflict of interest
The authors declare no conflict of interest.
-syn, -synuclein; AT1R, Angiotensin II type 1 receptor blocker; CMC, Carboxy methyl cellulose; IAEC, Institutional Animal Ethics Committee; LRRK2, Enriched with leucine repeats kinase 2; MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; MTA1, Metastasis-associated protein 1; PD, Parkinson’s disease; PINK1, PTEN-induced putative kinase 1; RAS, Renin angiotensin system; ROS, Reactive oxygen species; RT PCR, Reverse Transcriptase-Polymerase chain reaction; SEM, Standard error of the mean; SNpc, substantial nigra; STr, Striatum; TELM, Telmisartan; UCHL1, Ubiquitin C-terminal hydrolase L1.
-  Chidambaram SB, Bhat A, Ray B, Sugumar M, Muthukumar SP, Manivasagam T, et al. Cocoa beans improve mitochondrial biogenesis via PPAR/PGC1 dependent signalling pathway in MPP intoxicated human neuroblastoma cells (SH-SY5Y). Nutritional Neuroscience. 2020; 23: 471–480.
-  Martinez-Vicente M. Neuronal mitophagy in neurodegenerative diseases. Frontiers in Molecular Neuroscience. 2017; 10: 64.
-  Schapira AHV, Cooper JM, Dexter D, Jenner P, Clark JB, Marsden CD. Mitochondrial complex I deficiency in parkinson’s disease. The Lancet. 1989; 333: 1269.
-  Schapira AH, Cooper JM, Dexter D, Clark JB, Jenner P, Marsden CD. Mitochondrial complex I deficiency in Parkinson’s disease. Journal of Neurochemistry. 1990; 54: 823–827.
-  Vives-Bauza C, Tocilescu M, Devries RLA, Alessi DM, Jackson-Lewis V, Przedborski S. Control of mitochondrial integrity in Parkinson’s disease. Progress in Brain Research. 2010; 183: 99–113.
-  Parihar MS, Parihar A, Fujita M, Hashimoto M, Ghafourifar P. Mitochondrial association of alpha-synuclein causes oxidative stress. Cellular and Molecular Life Sciences. 2008; 65: 1272–1284.
-  Parihar MS, Parihar A, Fujita M, Hashimoto M, Ghafourifar P. Alpha-synuclein overexpression and aggregation exacerbates impairment of mitochondrial functions by augmenting oxidative stress in human neuroblastoma cells. The International Journal of Biochemistry & Cell Biology. 2009; 41: 2015–2024.
-  Hasan W, Rajak R, Kori RK, Yadav RS, Jat D. Neuroprotective effects of mitochondria-targeted quercetin against rotenone-induced oxidative damage in cerebellum of mice. The International Journal of Nutrition, Pharmacology, Neurological Diseases. 2019; 9: 136–145.
-  Khalifeh M, Barreto GE, Sahebkar A. Trehalose as a promising therapeutic candidate for the treatment of Parkinson’s disease. British Journal of Pharmacology. 2019; 176: 1173–1189.
-  Saeed U, Lang AE, Masellis M. Neuroimaging advances in parkinson’s disease and atypical parkinsonian syndromes. Frontiers in Neurology. 2020; 11: 572976.
-  Venkateshgobi V, Rajasankar S, Johnson WMS, Prabu K, Ramkumar M. Neuroprotective effect of agaricus blazei extract against rotenone-induced motor and nonmotor symptoms in experimental model of parkinson’s disease. The International Journal of Nutrition, Pharmacology, Neurological Diseases. 2018; 8: 59–65.
-  Labandeira-Garcia JL, Rodriguez-Pallares J, Rodríguez-Perez AI, Garrido-Gil P, Villar-Cheda B, Valenzuela R, et al. Brain angiotensin and dopaminergic degeneration: relevance to Parkinson’s disease. American Journal of Neurodegenerative Disease. 2012; 1: 226–244.
-  Labandeira-Garcia JL, Rodriguez-Pallares J, Villar-Cheda B, Rodríguez-Perez AI, Garrido-Gil P, Guerra MJ. Aging, Angiotensin system and dopaminergic degeneration in the substantia nigra. Aging and Disease. 2011; 2: 257–274.
-  Sathiya S, Ranju V, Kalaivani P, Priya RJ, Sumathy H, Sunil AG, et al. Telmisartan attenuates MPTP induced dopaminergic degeneration and motor dysfunction through regulation of -synuclein and neurotrophic factors (BDNF and GDNF) expression in C57BL/6J mice. Neuropharmacology. 2013; 73: 98–110.
-  Sekar S, Mani S, Rajamani B, Manivasagam T, Thenmozhi AJ, Bhat A, et al. Telmisartan ameliorates astroglial and dopaminergic functions in a mouse model of chronic Parkinsonism. Neurotoxicity Research. 2018; 34: 597–612.
-  An J, Nakajima T, Kuba K, Kimura A. Losartan inhibits LPS-induced inflammatory signaling through a PPARgamma-dependent mechanism in human THP-1 macrophages. Hypertension Research. 2010; 33: 831–835.
-  Grammatopoulos TN, Jones SM, Ahmadi FA, Hoover BR, Snell LD, Skoch J, et al. Angiotensin type 1 receptor antagonist losartan, reduces MPTP-induced degeneration of dopaminergic neurons in substantia nigra. Molecular Neurodegeneration. 2007; 2: 1.
-  Moradganjeh A, Ziai SA, Roghani M. Losartan pretreatment reduces neurodegeneration and behavioural symptoms in 6-hydroxydopamine induced unilateral rat model of Parkinson’s disease. Pathophysiology. 2013; 20: 243–248.
-  Abadir PM, Foster DB, Crow M, Cooke CA, Rucker JJ, Jain A, et al. Identification and characterization of a functional mitochondrial angiotensin system. Proceedings of the National Academy of Sciences. 2011; 108: 14849–14854.
-  Liang Y, Huang M, Jiang X, Liu Q, Chang X, Guo Y. The neuroprotective effects of Berberine against amyloid -protein-induced apoptosis in primary cultured hippocampal neurons via mitochondria-related caspase pathway. Neuroscience Letters. 2017; 655: 46–53.
-  Qi H, Shen D, Jiang C, Wang H, Chang M. Ursodeoxycholic acid protects dopaminergic neurons from oxidative stress via regulating mitochondrial function, autophagy, and apoptosis in MPTP/MPP-induced Parkinson’s disease. Neuroscience Letters. 2021; 741: 135493.
-  Seydi E, Mehrpouya L, Sadeghi H, Rahimi S, Pourahmad J. Luteolin attenuates Fipronil-induced neurotoxicity through reduction of the ROS-mediated oxidative stress in rat brain mitochondria. Pesticide Biochemistry and Physiology. 2021; 173: 104785.
-  Yang P, Sheng D, Guo Q, Wang P, Xu S, Qian K, et al. Neuronal mitochondria-targeted micelles relieving oxidative stress for delayed progression of Alzheimer’s disease. Biomaterials. 2020; 238: 119844.
-  Luchtman DW, Shao D, Song C. Behavior, neurotransmitters and inflammation in three regimens of the MPTP mouse model of Parkinson’s disease. Physiology & Behavior. 2009; 98: 130–138.
-  Paxinos G, Franklin KBJ. Paxinos and Franklin’s the mouse brain in stereotaxic coordinates. Cambridge: Academic Press. 2019.
-  Mani S, Sekar S, Barathidasan R, Manivasagam T, Thenmozhi AJ, Sevanan M, et al. Naringenin decreases -Synuclein expression and neuroinflammation in MPTP-induced Parkinson’s disease model in mice. Neurotoxicity Research. 2018; 33: 656–670.
-  Kim ST, Son HJ, Choi JH, Ji IJ, Hwang O. Vertical grid test and modified horizontal grid test are sensitive methods for evaluating motor dysfunctions in the MPTP mouse model of Parkinson’s disease. Brain Research. 2010; 1306: 176–183.
-  Keeney PM, Xie J, Capaldi RA, Bennett JP. Parkinson’s disease brain mitochondrial complex I has oxidatively damaged subunits and is functionally impaired and misassembled. The Journal of Neuroscience. 2006; 26: 5256–5264.
-  Schapira AH, Mann VM, Cooper JM, Dexter D, Daniel SE, Jenner P, et al. Anatomic and disease specificity of NADH CoQ1 reductase (complex I) deficiency in Parkinson’s disease. Journal of Neurochemistry. 1990; 55: 2142–2145.
-  Valenzuela R, Costa-Besada MA, Iglesias-Gonzalez J, Perez-Costas E, Villar-Cheda B, Garrido-Gil P, et al. Mitochondrial angiotensin receptors in dopaminergic neurons. Role in cell protection and aging-related vulnerability to neurodegeneration. Cell Death & Disease. 2016; 7: e2427.
-  Rodriguez-Pallares J, Rey P, Parga JA, Muñoz A, Guerra MJ, Labandeira-Garcia JL. Brain angiotensin enhances dopaminergic cell death via microglial activation and NADPH-derived ROS. Neurobiology of Disease. 2008; 31: 58–73.
-  Sathiya S, Babu CS. Telmisartan alleviates nitrosative stress in turn dopaminergic degeneration in mice MPTP model of parkinsonism—biochemical and histopathological evidences. International Journal of Pharmacy and Pharmaceutical Sciences. 2015; 7: 97–101.
-  Charan RA, LaVoie MJ. Pathologic and therapeutic implications for the cell biology of parkin. Molecular and Cellular Neurosciences. 2015; 66: 62–71.
-  Dave KD, De Silva S, Sheth NP, Ramboz S, Beck MJ, Quang C, et al. Phenotypic characterization of recessive gene knockout rat models of Parkinson’s disease. Neurobiology of Disease. 2014; 70: 190–203.
-  Villeneuve LM, Purnell PR, Boska MD, Fox HS. Early expression of Parkinson’s disease-related mitochondrial abnormalities in PINK1 knockout rats. Molecular Neurobiology. 2016; 53: 171–186.
-  Narendra D, Tanaka A, Suen D, Youle RJ. Parkin is recruited selectively to impaired mitochondria and promotes their autophagy. The Journal of Cell Biology. 2008; 183: 795–803.
-  Wood-Kaczmar A, Gandhi S, Yao Z, Abramov AY, Abramov ASY, Miljan EA, et al. PINK1 is necessary for long term survival and mitochondrial function in human dopaminergic neurons. PLoS ONE. 2008; 3: e2455.
-  Yu W, Sun Y, Guo S, Lu B. The PINK1/Parkin pathway regulates mitochondrial dynamics and function in mammalian hippocampal and dopaminergic neurons. Human Molecular Genetics. 2011; 20: 3227–3240.
-  Sánchez-Danés A, Richaud-Patin Y, Carballo-Carbajal I, Jiménez-Delgado S, Caig C, Mora S, et al. Disease-specific phenotypes in dopamine neurons from human iPS-based models of genetic and sporadic Parkinson’s disease. EMBO Molecular Medicine. 2012; 4: 380–395.
-  Reinhardt P, Schmid B, Burbulla LF, Schöndorf DC, Wagner L, Glatza M, et al. Genetic correction of a LRRK2 mutation in human iPSCs links parkinsonian neurodegeneration to ERK-dependent changes in gene expression. Cell Stem Cell. 2013; 12: 354–367.
-  Ludtmann MHR, Kostic M, Horne A, Gandhi S, Sekler I, Abramov AY. LRRK2 deficiency induced mitochondrial Ca2 efflux inhibition can be rescued by Na/Ca2/Li exchanger upregulation. Cell Death & Disease. 2019; 10: 265.
-  Toyofuku T, Okamoto Y, Ishikawa T, Sasawatari S, Kumanogoh A. LRRK2 regulates endoplasmic reticulum–mitochondrial tethering through the PERK-mediated ubiquitination pathway. The EMBO Journal. 2020; 39: e100875.
-  Agliardi C, Meloni M, Guerini FR, Zanzottera M, Bolognesi E, Baglio F, et al. Oligomeric -syn and SNARE complex proteins in peripheral extracellular vesicles of neural origin are biomarkers for Parkinson’s disease. Neurobiology of Disease. 2021; 148: 105185.
-  Volpicelli-Daley LA, Luk KC, Patel TP, Tanik SA, Riddle DM, Stieber A, et al. Exogenous -synuclein fibrils induce Lewy body pathology leading to synaptic dysfunction and neuron death. Neuron. 2011; 72: 57–71.
-  Zhang L, Shimoji M, Thomas B, Moore DJ, Yu S, Marupudi NI, et al. Mitochondrial localization of the Parkinson’s disease related protein DJ-1: implications for pathogenesis. Human Molecular Genetics. 2005; 14: 2063–2073.
-  Mitsumoto A, Nakagawa Y. DJ-1 is an indicator for endogenous reactive oxygen species elicited by endotoxin. Free Radical Research. 2002; 35: 885–893.
-  Shendelman S, Jonason A, Martinat C, Leete T, Abeliovich A. DJ-1 is a redox-dependent molecular chaperone that inhibits alpha-synuclein aggregate formation. PLoS Biology. 2004; 2: e362.
-  Xu C, Kang W, Chen Y, Jiang T, Zhang J, Zhang L, et al. DJ-1 Inhibits -Synuclein aggregation by regulating chaperone-mediated autophagy. Frontiers in Aging Neuroscience. 2017; 9: 308.
-  Cartier AE, Ubhi K, Spencer B, Vazquez-Roque RA, Kosberg KA, Fourgeaud L, et al. Differential effects of UCHL1 modulation on alpha-synuclein in PD-like models of alpha-synucleinopathy. PLoS ONE 2012; 7: e34713.
-  Kumar R, Jangir DK, Verma G, Shekhar S, Hanpude P, Kumar S, et al. S-nitrosylation of UCHL1 induces its structural instability and promotes -synuclein aggregation. Scientific Reports. 2017; 7: 44558.
-  Osaka H, Wang Y-L, Takada K, Takizawa S, Setsuie R, Li H, et al. Ubiquitin carboxy-terminal hydrolase L1 binds to and stabilizes monoubiquitin in neuron. Human Molecular Genetics. 2003; 12: 1945–1958.
-  Kumar AS, Jagadeeshan S, Subramanian A, Chidambaram SB, Surabhi RP, Singhal M, et al. Molecular Mechanism of Regulation of MTA1 Expression by Granulocyte Colony-stimulating Factor. Journal of Biological Chemistry. 2016; 291: 12310–12321.
-  Lev N, Barhum Y, Pilosof NS, Ickowicz D, Cohen HY, Melamed E, et al. DJ-1 protects against dopamine toxicity: implications for Parkinson’s disease and aging. The Journals of Gerontology: Series A, Biological Sciences and Medical Sciences. 2013; 68: 215–225.
-  Mita Y, Kataoka Y, Saito Y, Kashi T, Hayashi K, Iwasaki A, et al. Distribution of oxidized DJ-1 in Parkinson’s disease-related sites in the brain and in the peripheral tissues: effects of aging and a neurotoxin. Scientific Reports: Nature Publishing Group. 2018; 8: 12056.