👤 Christian Honoré

Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in the elderly. Aging is the most important risk factor for AMD, and the aging immune system seems to be involved in pathogenesis. This study investigates the systemic aging immune profile in relation to AMD stage and treatment response. Treatment-naïve patients with neovascular AMD (nAMD), intermediate AMD and healthy controls were included in this prospective study. Participants were examined for systemic aging immune profiles and compared to AMD stage, as well as initial and one-year treatment response in nAMD patients. Flowcytometry was performed to determine T cell differentiation (naïve, central memory and effector memory) and expression of costimulatory markers (CD27, CD28, CD56). Cytokine assays were performed to measure the concentrations of plasma cytokines IFN-γ, IL-1β, IL-2, IL-6, IL-10, IL-12, IL-17, IL-22, IL-27, TNF-α. Polymorphisms of CFH and ARMS2 genes were compared in nAMD patients. Patients with nAMD had significantly higher proportions of central and effector memory CD8+ T cells compared to controls (both P < 0.036). nAMD patients had significantly elevated concentrations of IFN-γ, IL-1β, IL-2, and IL-10 (all P < 0.05). nAMD patients with poor initial treatment response had a significantly higher concentration of plasma IFN-γ compared to good responders (P =0.026). Patients with nAMD had a more advanced systemic aging immune profile with higher levels of T cell differentiation and plasma cytokines compared to controls. Poor initial response had elevated levels of plasma IFN-γ compared to good responders in nAMD. Show less

Mice lacking the bHLH transcription factor (TF) Neurog3 do not form pancreatic islet cells, including insulin-secreting beta cells, the absence of which leads to diabetes. In humans, homozygous mutations of NEUROG3 manifest with neonatal or childhood diabetes. Despite this critical role in islet cell development, the precise function of and downstream genetic programs regulated directly by NEUROG3 remain elusive. Therefore, we mapped genome-wide NEUROG3 occupancy in human induced pluripotent stem cell (hiPSC)-derived endocrine progenitors and determined NEUROG3 dependency of associated genes to uncover direct targets. We generated a novel hiPSC line (NEUROG3-HA-P2A-Venus) where NEUROG3 is HA-tagged and fused to a self-cleaving fluorescent VENUS reporter. We used the CUT&RUN technique to map NEUROG3 occupancy and epigenetic marks in pancreatic endocrine progenitors (PEP) that were differentiated from this hiPSC line. We integrated NEUROG3 occupancy data with chromatin status and gene expression in PEPs as well as their NEUROG3-dependence. In addition, we investigated whether NEUROG3 binds type 2 diabetes mellitus (T2DM)-associated variants at the PEP stage. CUT&RUN revealed a total of 863 NEUROG3 binding sites assigned to 1263 unique genes. NEUROG3 occupancy was found at promoters as well as at distant cis-regulatory elements that frequently overlapped within PEP active enhancers. De novo motif analyses defined a NEUROG3 consensus binding motif and suggested potential co-regulation of NEUROG3 target genes by FOXA or RFX transcription factors. We found that 22% of the genes downregulated in NEUROG3 Mapping NEUROG3 genome occupancy in PEPs uncovered unexpectedly broad, direct control of the endocrine genes, raising novel hypotheses on how this master regulator controls islet and beta cell differentiation. Show less