Multimodal Regulation Orchestrates Normal and Complex Disease States in the Retina

Abstract

Regulation of biological processes occurs through complex, synergistic mechanisms. In this study, we discovered the synergistic orchestration of multiple mechanisms regulating the normal and diseased state (age related macular degeneration, AMD) in the retina. We uncovered gene networks with overlapping feedback loops that are modulated by nuclear hormone receptors (NHR), miRNAs, and epigenetic factors. We utilized a comprehensive filtering and pathway analysis strategy comparing miRNA and microarray data between three mouse models and human donor eyes (normal and AMD). The mouse models lack key NHRS (Nr2e3, RORA) or epigenetic (Ezh2) factors. Fifty-four total miRNAs were differentially expressed, potentially targeting over 150 genes in 18 major representative networks including angiogenesis, metabolism, and immunity. We identified sixty-eight genes and 5 miRNAS directly regulated by NR2E3 and/or RORA. After a comprehensive analysis, we discovered multimodal regulation by miRNA, NHRs, and epigenetic factors of three miRNAs (miR-466, miR1187, and miR-710) and two genes (Ell2 and Entpd1) that are also associated with AMD. These studies provide insight into the complex, dynamic modulation of gene networks as well as their impact on human disease, and provide novel data for the development of innovative and more effective therapeutics.

Cone Vision Changes in the Enhanced S-Cone Syndrome Caused byNR2E3Gene Mutations

“…1,3,15 Progress in understanding photoreceptor developmental pathways has proceeded (for example, see Refs. [16][17][18][19][20] and experiments now suggest that nuclear receptors can be modulators of disease and could play a role in therapy, including the retinal degeneration resulting from NR2E3 mutations. 21,22 Given the possibility of therapy, the present study was performed using both cross-sectional and longitudinal studies of patients with NR2E3 mutations to begin to understand how this unique group of diseases could be monitored through a clinical trial intending to alter therapeutically the natural history of disease.…”

Nr2e3 is a genetic modifier that rescues retinal degeneration and promotes homeostasis in multiple models of retinitis pigmentosa

“…Chromatin immunoprecipitation (chIP) was performed using P30 C57Bl6/J mouse retinas as previously described [49]. A total of 8-10 retinas were used per chIP reaction.…”

“…NHR genes such as Nr2e3 play key roles in modulating homeostasis by regulating many key biological processes and gene networks. Our prior studies and recent Ingenuity Pathway Analysis revealed that Nr2e3 regulates several key biological networks that are critical to maintaining retina homeostasis in the retina including phototransduction, cell survival, apoptosis, immunity, oxidative stress, ER stress, neuroprotection, and metabolism [49]. Representative subsets of treated animals (rd7, Rho −/− , and rd1) were evaluated for differential expression of genes that function in Nr2e3 regulated pathways.…”

“…NR2E3 mutations are also associated with up to 1% of all autosomal dominant retinitis pigmentosa (adRP) [44,45]. The association of NR2E3 with several clinical phenotypes and varying modes of inheritance strongly indicates that these retinal diseases manifest on a permissive or selective genetic background and are influenced, at least in part, by genetic modifier genes [46][47][48][49]. Given the role of NHRs such as NR2E3, to modulate numerous key biological networks essential for maintaining retinal homeostasis, this study evaluated Nr2e3 as a broadspectrum genetic modifier with the potential to attenuate retinal degeneration in several different mouse models.…”

Identification of novel mouse and rat CB1R isoforms and in silico modeling of human CB1R for peripheral cannabinoid therapeutics

“…The extended mCB1R exon 1 might imply that the mouse Cnr1 promoter is more upstream than previously thought, and potential transcription factors may aid in the generation of Cre-Lox recombinant knockout mice and de novo viral expression for mCB1 cell type-specific studies. We conducted a miRBase search using the mCB1 3′UTR of 3.7 kb sequence [27] with an E-value cutoff of 0.1 and found that a mouse mature microRNA target of mCB1R (nucleotide position at NM_007726: 3688-3126) contains a cluster [41] of miR-466i-5p, miR-574-5p, and miR-1187 involved in retina disease and white adipose tissue hypertrophy [42,43]. The evolution of transcription factor and miRNA binding sites of rodent Cnr1 is different from that of human CNR1 [12].…”