# Comprehensive Proteomic Profiling Reveals Dysregulation of Angiogenesis and Inflammatory Pathways in the Brains of SIRT3 Knockout Mice

## TL;DR

This study shows that the absence of SIRT3 in mice leads to changes in brain proteins related to blood vessel growth, cell death, and inflammation, suggesting a link to neurodegeneration.

## Contribution

The study provides the first comprehensive proteomic analysis of SIRT3's role in regulating brain angiogenesis, apoptosis, and inflammation pathways.

## Key findings

- SIRT3 knockout mice showed suppressed angiogenic proteins and altered apoptotic and stress-related proteins.
- Increased inflammatory mediators linked to glial activation and neurodegeneration were observed in SIRT3-deficient brains.
- SIRT3 deficiency disrupts immune surveillance and vascular remodeling proteins in the brain.

## Abstract

Background: Sirtuin 3 (SIRT3), a mitochondrial NAD+-dependent deacetylase, plays a central role in regulating mitochondrial metabolism, oxidative stress, and cell survival. Although SIRT3 has been implicated in angiogenesis, apoptosis, and inflammation, its global proteomic impact on the brain remains unclear. This study aimed to systematically characterize alterations in angiogenesis-, apoptosis-, chemokine-, and cytokine-related proteins in the brains of SIRT3 knockout (SIRT3 KO aka SIRT3−/−) mice compared with wild-type (WT) controls. Methods: Adult male C57BL/6 WT and SIRT3 KO mice were analyzed using proteome profiler antibody microarrays covering 53 angiogenesis factors, 21 apoptosis markers, 28 chemokines, and 111 cytokines. Protein expression changes were quantified by chemiluminescence imaging and densitometric analysis. Results: The results showed a distinct suppression of angiogenic proteins (amphiregulin, angiogenin, DPPIV, GM-CSF, IGFBP-2, IGFBP-3, IL-1β, PDGF-AA, PDGF-BB, proliferin, serpin F1, thrombospeondin-2, TIMP-4, and VEGF-B), activation of both pro-apoptotic (BAD, cytochrome c, Smac/DIABLO, HIF-1α, Fas, TNF R1, and TRAILR2) and anti-apoptotic, stress-related proteins (Bcl-x, catalase, HO/HMOX2, HSP27, HSP70, and MCL1) in the SIRT3 KO animals compared with the WT controls. Notably, SIRT3 deficiency was associated with increased expression of inflammatory mediators linked to glial activation and neurodegeneration (BLC/CCL13, LIX/CXCL5, MIG/CXCL9, chitinase 3-like 1, CCL22/MDC, IL-6, myeloperoxidase, osteopontin, RBP4, Reg3G, and TNF-α), alongside disturbed proteins involved in immune surveillance and vascular remodeling (6Ckine/CCL21, chemerin, DF, EGF, fractalkine/CX3CL1, HGF, IGFBP-6, IL-16, and I-TAC). Conclusions: Collectively, these findings demonstrate that SIRT3 is a key regulator of mitochondrial-dependent vascular, apoptotic, and neuroimmune pathways in the brain, and that its loss creates a molecular environment consistent with heightened vulnerability to neurodegenerative processes.