Table 1.
Role of NOX2 in Parkinson’s disease.
| Models | Treatments | Results | Ref |
|---|---|---|---|
| In Vitro and Vivo Experimental Models | |||
| Primary microglial cells obtained from whole brains of wild type (WT) or CD11b−/− mice; microglia BV2 cell line |
α-Syn (50, 100, and 200) nM; pre-treatment with anti-CD11b antibody (2.5 μg/mL) for 30 min. |
The translocation of p47PHOX into the membrane and consequently, ROS production in microglia α-Syn-induced. BV2 microglia α-Syn-induced were pre-treated with anti-CD11b antibody to block CD11b activation for demonstrating its implication in NOX2 activation. | [67] |
| Adult male SD rats (9 weeks old); Primary mesencephalic neuron-glia, microglia-depleted, and mixed-glia cultures; BV2 microglial cell line; |
Intraperitoneal injection of HD (400 mg/kg/die) five times in 1 week for consecutive 5 weeks in rats; HD (1, 4, 8, and 16) mM. |
Increased levels of both ROS and p47PHOX levels were observed in HD-treated BV2 microglia, demonstrating NOX2 activation. Instead, microglia cells were pre-treated with apocynin (NOX2 inhibitor), further suggesting that NOX2 was responsible for inducing ROS production. Furthermore, integrin αMβ2 (also known as CD11b) has been shown to be involved in NOX2 activation. Indeed, its inhibition would reduce ROS and p47PHOX translocation. | [68] |
| BV2 microglial cells | Combination of paraquat and maneb (10 + 0.6) μM. | The co-treatment induced an increase in ROS levels and p47PHOX translocation, evidencing NOX2 activation. Furthermore, the inactivation of the C3 receptor (integrins) decreased the production of superoxide and translocation of p47PHOX, supporting the involvement of integrins in the activation of NOX2. The inactivation of integrins impacted the Src-ERK pathway. | [69] |
| Male C57BL/6J (NOX2+/+ and NOX2−/−) mice | Intraperitoneal injection of paraquat + maneb (10 + 30) mg/kg 2 times in one week for 6 weeks in mice; Pre-treatment with Taurine (150 mg/kg) |
Exposure to paraquat + maneb induced both an increase in NOX2 subunits (p47PHOX and gp91PHOX), as well as α-Syn expression levels which demonstrate neurodegeneration. Moreover, NOX2 could induce microglial polarization. Instead, pretreatment with taurine counteracted neurodegeneration and reduced translocation of NOX2 subunits. | [70] |
| Male C57BL/6J (NOX2+/+ and NOX2−/−) mice; neuron-glia culture cells obtained from mouse or rat embryos; HAPI cells |
Injection of A29-V40 (α-Syn) peptide (5 mg/kg) for 24 h in mice; Treatment with PMA (100 Nm) or LPS (150 EU/mL); Pre-treatment with apocynin (0.25 mM) |
PMA and A29-V40 treatment-induced translocation of p47PHOX and p67PHOX and could bind gp91PHOX subunit in mice. The co-treatment with apocynin restored the viability of dopaminergic neurons and their ability to DA uptake. Instead, microglia culture pre-treated with H2O2 in gp91PHOX −/− microglia promoted the phosphorylation of p47PHOX and Erk1/2 demonstrating that several factors could affect NOX2 activation. | [71] |
| Primary midbrain neuron-glia cultures obtained from brains of SD rats; primary glia cultures obtained from NOX2+/+ and NOX2−/− mice; Male C57BL/6J (NOX2+/+ and NOX2−/−) mice; |
Cultures were treated with LPS (0.5 ng/mL) and/or Syn (20 nmol/L) for 8 days LPS (0.2 ug/uL) + syn (0.0125 ug/uL) treatment was administered in mice. Pre-treatment with DPI (0.01 and 0.1) μM |
ROS levels, p47PHOX, and gp91PHOX were increased after LPS + syn treatment. Interestingly, a decrease in both dopaminergic levels and DA uptake was found in NOX2+/+ mice. Conversely, both the number of microglia and the ROS levels increased. The same results were found in rat primary midbrain neuron-glia cultures obtained from NOX2+/+ and NOX2−/− mice. Instead, DPI improved the viability of dopaminergic neurons and reduced ROS. | [72] |
| neuron-glia mixed culture cells of Time-pregnant Fisher F344 rats Wild-type C57BL/6J (gp91phox+/+) and NOX2-deficient (gp91phox−/−) mice |
LPS (15 ng/mL) or MPP+ (0.25 μM) treatment MPTP injections (20 mg/kg, s.c.) for 6 days. One day prior to MPTP injection, clozapine or CNO (1 mg/kg, s.c.) was administered twice daily for 21 consecutive days and pre-treatment with DPI (3 mg/kg, i.p) |
LPS-treatment in NOX2+/+ mice promoted both mRNA NOX2 expression and release of ROS in a time-dependent manner. Co-treatment with CNO or NDC showed how NOX2 activation influenced DA uptake and release of pro-inflammatory compounds. DPI-Pre-treatment reduced both ROS and inflammatory cytokines such as TNFα, MCP-1, and LPS-induced IL-1β | [73] |
| B6.129S6-Cybbtm1Din (NOX2−/−) and C57BL/6J 000,664 (NOX2+/+) mice | Intraperitoneal injection of LPS (5 mg/kg). | LPS-treatment in C57BL/6J mice promoted both mRNA NOX2 expression and release of ROS in a time-dependent manner. Instead, pre-treatment with DPI reduced both ROS and inflammatory cytokines such as TNFα, MCP-1and IL-1β demonstrating that NOX2 promoting microglia activation, subsequently the release of inflammatory cytokines. | [74] |
| Mixed-glia cultures of B10.129P2(B6)-IL-10tm1Cgn/J (IL-10 knockout or IL-10−/−) mice and their WT or IL-10+/+ control mice (C57BL/10J), as well as B6N.129S2-Casp1tm1Flv/J (caspase-1 knockout or CASP-1−/−) mice and their WT (CASP-1+/+) control mice. | Intranigral injection of LPS (3 μg) | NOX2 activation and the consequent increase in ROS were responsible for the activation of NLPR3 inflammasome. The increased levels of IL-10 were able to suppress ROS-NOX2 induced and to block the NLPR3 activation, preventing neuroinflammation. | [75] |
| Microglial cultures of male C57BL/6J and NOD2 knockout (NOD2−/−) mice. BV2 microglial cells SH-SY5Y cells |
Injection of 6-OHDA (2 μL) Injection of MDP (4 μg/μL) in the right striatum |
Treatment with MDP or 6-OHDA induced a reduction in DA and an increase in both apoptotic proteins and inflammatory cytokines. Instead, increased NOX2, NOD2, and iNOS promoting neuroinflammation was observed in 6-OHDA-induced microglia. | [76] |
| Ten week-old male C57BL/6 (gp91PHOX−/−) and WT mice Microglial cultures C57BL/6) and gp91PHOX−/− mice |
6-OHDA (10 µg/µL) was unilaterally injected into the right striatum Minocycline (40 mg/kg) was injected(i.p) 7 days before PD induction |
Treatment with 6-OHDA in the striatum of gp91PHOX−/− mice reduced the dopaminergic neurons, explaining NOX2-mediated neurotoxicity. Furthermore, co-treatment with minocycline promoted the neurodegeneration and release of TNFα in gp91PHOX+/+ mice, supporting NOX2 activation. | [77] |
| Microglial cultures of C57 BL/6J (NOX2+/+ and NOX2−/−) mice. | Fe2+-treatment (5, 25, and 100) μM | Treatment with Fe2+ significantly increases both p47PHOX and gp91PHOX expression, suggesting Fe2+-induced NOX2 activation. Moreover, an increase in mRNA expression and protein levels of p38, ERK 1/2, and JNK was observed, therefore Fe2+ exposure could promote neuroinflammation. | [78] |
| Mesencephalic neuron-glia, microglia-depleted, and microglia-enriched cultures of C57BL/6J, SP-deficient (TAC1−/−), and SP receptor-deficient (NK1R−/−)mice | Treatment with LPS (15 × 106 EU/kg) or MPTP (15 mg/kg) for 6 days | Significant loss of dopaminergic neurons was observed in WT mice treated with SP + LPS or SP + MPP + compared to gp91PHOX−/− culture, thus it was inferred that NOX2 may play a role in promoting neurotoxicity. Moreover, it was observed an increase in the translocation of p47PHOX and p67PHOX as well as of several inflammatory factors such as TNFα, iNOS, and MCP-1, suggesting activation of NOX2. Furthermore, MAPK and NF-Κb pathways were activated by NOX2 in microglia after toxicity-induced. | [79] |
| Mesencephalic neuron-glia cultures from the ventral mesencephalon of embryonic Fischer 334 rats and also on A53T mutant α-synuclein transgenic mice. | The intranigral and intraperitoneal injection of LPS (5 mg/kg) and subcutaneous injection MPTP (15 mg/kg) | Increased levels in both gp91PHOX and G6PD were observed after LPS or MPTP treatment in mice. Neuron-glia culture treated with LPS demonstrated an increase of NADPH levels and G6PD activity, so it could be the promoter of NOX2 activation that induces neuroinflammation. Moreover, an increase of both G6PD and NOX2 in microglia are responsible to implement oxidative stress, the NF-Kb translocation, and subsequent neurodegeneration. | [63] |
WT: wild type; CD11b: cluster of differentiation molecule 11b; α-Syn: α-Synuclein; ROS: reactive oxygen species; NOX2: NADPH oxidase 2; SD: Sprague Dawley; HD: 2,5-hexanedione; Src: Proto-oncogene tyrosine-protein kinase; ERK: extracellular signal-regulated kinase; DA: dopamine; HAPI: highly aggressively proliferating immortalized; PMA: phorbol 12-myristate 13-acetate; LPS: lipopolysaccharide; H2O2: hydrogen peroxide; DPI: diphenyleneiodonium; MPP+: 1-methyl-4-phenylpyridinium; MPTP: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; CNO: clozapine N-oxide; NDC: N-Desmethylclozapine; TNFα: tumor necrosis factor-α; MCP-1: monocyte chemoattractant protein-1; IL-1β: interleukin-1beta; IL-10: interleukin-10; KO: knockdown; casp-1: caspase-1; NLRP3: NLR family pyrin domain containing 3; 6-OHDA: 6-hyroxydopamine; MDP: muramyl dipeptide; NOD2: Nucleotide-binding oligomerization domain-containing protein; Fe2+: iron (II); p38: p38 mitogen-activated protein kinase; JNK: c-Jun N-terminal kinase; SP: substance P; iNOS: inducible nitric oxidase synthase; MAPK: mitogen-activated protein kinase; NF-Kb: nuclear factor-Κb; G6PD: glucose-6-phosphatase-dehydrogenase.