Table 3.

Role of NOX2 in Amyotrophic Lateral Sclerosis.

Models	Treatments	Results	Ref
	In Vitro and Vivo Experimental Models
hSOD1-G93A rats and primary microglia	diphenyl diselenide (50 μmol/kg) via intraperitoneal diphenyl diselenide (400 nM)	In vivo, diphenyl diselenide reduced the progression of the disease and favored motor neuron survival. While the same treatment in microglia has reduced the expression of the gp91PHOX subunit of NOX2 and also the production of ROS. Moreover, diphenyl diselenide blocked the activation of the inflammasome and reduced the levels of caspase-1 and IL-1β.	[107]
hSOD1-G93A rats	a single injection of mesenchymal cells 2 × 106 labeled via intrathecal in the CSF	The infiltration and differentiation of mesenchymal cells in the injury site reduced the neurodegeneration of motor neurons in the spinal cord. Moreover, the transplantation of mesenchymal cells reduced inflammation and microglial activation as well as NOX2 and COX2 levels.	[108]
mSOD1 microglia	mSOD1 microglia (2000 cells/well) co-culturing with motoneurons	The study has demonstrated changes in mSOD1 microglia of the mouse from a neuroprotective to a neurotoxic phenotype, as well as increased in the expression of NOX2, ROS, and markers including Ym1, CD163, and BDNF.	[109]
mSOD1-G93A mice	mSOD1 microglia (1 × 104 cells/well) co-cultured with Tregs (1 × 104 cells/well) or Teffs cells (1 × 104 cells/well)	The study has shown the interaction between microglial activation and T lymphocytes, through a mechanism that involved IL-4 in the modulation of cytotoxicity. Indeed, Tregs through IL-4 reduced NOX2 and iNOS levels in primary microglial cells. Similarly, IL-4 inhibition promoted the increase of NOX2 and iNOS.	[110]
mSOD1-G93A mice	analysis of spinal cord sections	CD4 + infiltration in the lumbar spinal cord increased IL-4, BDNF, and GDNF levels, as well as promoted motor neuron survival. Similarly, it was shown in the cervical spinal cord both a reduction of the microglial activation and also a reduction in TNF-α, IL-1β, and NOX2.	[111]
mSOD1-G93A mice	bone marrow (3 × 107 cells per mouse) via intraperitoneal	The bone marrow transplantation has led to the recruitment of CD4+ lymphocytes which have preserved motor neurons from the neurodegeneration. Consequently, it was demonstrated the reduction of NOX2 levels and also the increase of BDNF, GDNF, and glutamate transporters.	[112]
MO59J glial cells and NSC-34 neuronal cells and SOD1-G93A mice	Glial MO59J cells (1.0 × 106) and NSC-34 (0.5 × 106) infected with adenoviruses (1000 particles per cell)	Both MO59J glial cells and NSC-34 neuronal cells SOD1G93A-expressing have demonstrated an increase in Rac1, NOX2, ROS, TNFα, and NF-κB levels. Similarly, alsin has shown a higher affinity for Rac1-GTP in MO59J cells, thus reducing Rac1 activation and therefore NOX2 activity.	[113]
Microglial cells and primary motoneuron of spinal cords obtained from C57BL/6 mice	TDP-43 treatment (500 ng/mL) in microglia for 2 days; LPS (40 ng/mL) and PMBS (4 μg/mL)	TDP-43 induced an increase in NOX2 expression and TNF-α and IL-1β levels as well as activation of NLRP3 inflammasome. Similarly, TDP-43 treatment in microglia was able to promote the MAPK and NF-κB pathway. Instead, PMBS co-treatment confirmed that microglia activation depended on TDP-43 and showed no significant changes in NOX2 expression and inflammatory cytokines.	[114]
SOD1-G93A transgenic mice	microglia SOD1-G93A treated with BzATP (10–100 μM)	BzATP improved the NOX2 activity and consequently ROS production through a mechanism mediated by translocation of p67PHOX. Moreover, the administration of apocyanine in microglia treated with BzATP has inhibited NOX2 and reduced ROS. Similarly, a relationship between NOX2 and ERK1/2 phosphorylation mediated by P2 × 7 receptors was demonstrated.	[105]
SOD1-G93A mice and Ra2 microglia	Ra2 microglia (10,000 cells/well) LPS-treated (5 µg/mL), perphenazine (3 mg/kg) or thioridazine (10 mg/kg) intraperitoneal administration	In vivo, it was shown an increase in the expression levels of p22PHOX, p67PHOX, and p47PHOX (NOX2 subunits). Moreover, thioridazine reduced NOX2 and ROS levels, as well as the expression levels of microglial markers Iba1 and CD68. Besides, either treatment with perphenazine or thioridazine in SOD1 G93A mice did not increase motor neuron survival, while in microglia inhibited ROS production and NOX2 activity.	[115]

NOX2: NADPH oxidase2; ROS: reactive oxygen species; IL-1β: interleukin-1beta; CSF: cerebrospinal fluid; SOD1: Superoxide dismutase; COX2: cyclooxygenase2; CD163: Cluster of Differentiation 163; BDNF: Brain-derived neurotrophic factor; IL-4: interleukin-4; iNOS: inducible nitric oxidase synthase; GDNF: Glial cell-derived neurotrophic factor; TNFα: tumor necrosis factor-α; Rac1: Ras-related C3 botulinum toxin substrate 1; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; GTP: Guanosine-5′-triphosphate; TDP-43: TAR DNA-binding protein 43; NLRP3: NLR family pyrin domain containing 3; LPS: lipopolysaccharide; PMBS: polymyxin B sulfate; MAPK: mitogen-activated protein kinase; BzATP:2′-3′-O-(benzoyl-benzoyl) ATP; ERK: extracellular signal-regulated kinase; Iba1: ionized calcium-binding adapter molecule 1; CD68: Cluster of Differentiation 68.