Multi-Functional Role of RECK in Metabolic Dysfunction-Associated Steatotic Liver Disease Development: A Mass Spectrometry-Proteomic Approach

Metabolic dysfunction-associated steatotic liver disease (MASLD, previously referred to as nonalcoholic fatty liver disease) is characterized by increased fat deposition and inflammation in the liver as well as dysregulation of cellular processes that affect the extracellular matrix (ECM). We previously observed that the expression of Reversion Inducing Cysteine Rich Protein with Kazal motifs (RECK), a key ECM regulatory protein, negatively correlates with MASLD-associated fibrosis and inflammation (metabolic dysfunction-associated steatohepatitis, MASH). However, mechanisms governing this relationship remain unclear. Therefore, we hypothesized that overexpression of RECK is hepatoprotective in the setting of MASH by altering several ECM-linked pathways, as analyzed by proteomics. Accordingly, we generated hepatocyte-specific Reck-overexpressing transgenic mice. Male hepatocyte-specific Reck-overexpressing transgenic mice and littermate controls were fed a Western diet high in fat, carbohydrate, and cholesterol for 24 weeks (n=6/group). Whole liver tissue was submitted for mass spectrometry-proteomic analysis. We identified 370 differentially expressed proteins out of a total of 4693 proteins using a q-value cutoff of ≤0.10; of which 90 proteins were significantly upregulated while 280 significantly downregulated. This included an upregulation of Cyp2b (adjusted p≤0.01) and downregulation of Taok1, C/EBPβ, and Vitronectin (all adjusted p≤0.01), all of which have been shown to be important in liver health and metabolism in the context of MASH. Predictive pathway analysis using Ingenuity Pathway Analysis software (Qiagen) identified several significantly altered pathways, including those involved in ECM regulator pathways (integrin signaling, z-score=6.0; mTOR signaling, z-score=5.3; leukocyte extravasation signaling, z-score=5.1), cell-signaling (chemokine signaling, z-score=5.4; CXCR4 signaling chemokine signaling, z-score=5.0), and inflammatory responses (leukocyte extravasation signaling, z-score=5.1; CXCR4 signaling, z-score=5.0). Interestingly, pathway analysis based on significantly altered proteins predicted the downregulation of critical components of hepatic inflammation and fibrosis, including TGF-β, IL-1β, and TNFα. These novel results reveal the regulatory role of RECK in MASH progression, specifically governing the components of ECM remodeling and inflammation. Our goal is to develop RECK inducers and identify additional therapeutic targets in MASH development and progression. This work was funded by the NIH award R01DK130243. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.