Nrf2 activation by sulforaphane restores the age-related decrease of TH1 immunity: Role of dendritic cells

AbstractAge-related macular degeneration (AMD) is genetically associated with complement. Dendritic cells (DCs) play key roles during innate and adaptive immunity, and express complement components and their receptors. We investigated ocular DC heterogeneity and the role of DCs in the laser-induced choroidal neovascularization (CNV) model. In order to determine the function of DCs, we used two models of DC deficiency: the Flt3−/− and Flt3l−/− mouse. We identified three types of ocular DCs: plasmacytoid DC, classical DC-1, and classical DC-2. At steady-state, classical DCs were found in the iris and choroid but were not detectable in the retina. Plasmacytoid DCs existed at very low levels in iris, choroid, and retina. After laser injury, the number of each DC subset was up-regulated in the choroid and retina. In Flt3−/− mice, we found reduced numbers of classical DCs at steady-state, but each DC subset equally increased after laser injury between wildtype and Flt3−/− mice. In Flt3l−/− mice, each DC subsets was severely reduced after laser injury. Neither Flt3−/− or Flt3l−/− mice demonstrated reduced CNV area compared to wildtype mice. DCs do not play any significant role during the laser-induced CNV model of neovascular AMD.

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An Overview of the Nrf2/ARE Pathway and Its Role in Neurodegenerative Diseases

International Journal of Molecular Sciences ◽

10.3390/ijms22179592 ◽

2021 ◽

Vol 22 (17) ◽

pp. 9592

Author(s):

Emilia Zgorzynska ◽

Barbara Dziedzic ◽

Anna Walczewska

Keyword(s):

Leucine Zipper ◽

Target Genes ◽

Protective Efficacy ◽

Antioxidant Response ◽

Activation Mechanism ◽

Age Related ◽

Nrf2 Activation ◽

Metabolic Conditions ◽

Lateral Sclerosis

Nrf2 is a basic region leucine-zipper transcription factor that plays a pivotal role in the coordinated gene expression of antioxidant and detoxifying enzymes, promoting cell survival in adverse environmental or defective metabolic conditions. After synthesis, Nrf2 is arrested in the cytoplasm by the Kelch-like ECH-associated protein 1 suppressor (Keap1) leading Nrf2 to ubiquitin-dependent degradation. One Nrf2 activation mechanism relies on disconnection from the Keap1 homodimer through the oxidation of cysteine at specific sites of Keap1. Free Nrf2 enters the nucleus, dimerizes with small musculoaponeurotic fibrosarcoma proteins (sMafs), and binds to the antioxidant response element (ARE) sequence of the target genes. Since oxidative stress, next to neuroinflammation and mitochondrial dysfunction, is one of the hallmarks of neurodegenerative pathologies, a molecular intervention into Nrf2/ARE signaling and the enhancement of the transcriptional activity of particular genes are targets for prevention or delaying the onset of age-related and inherited neurogenerative diseases. In this study, we review evidence for the Nrf2/ARE-driven pathway dysfunctions leading to various neurological pathologies, such as Alzheimer’s, Parkinson’s, and Huntington’s diseases, as well as amyotrophic lateral sclerosis, and the beneficial role of natural and synthetic molecules that are able to interact with Nrf2 to enhance its protective efficacy.

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