P0073 Evaluation of PYGL as a Biomarker and Therapeutic Target in Ulcerative Colitis
Authors: Kang MD.- PhD. S B , Yang C H 
Published: January 2025

Background

Inflammation begins when innate immune cells recognize and respond to infections or tissue injuries to protect the body. In particular, cells such as macrophages and dendritic cells require more energy to manage these conditions. Glycogen metabolism is a crucial function for cells recruited to the site of inflammation to obtain energy. Within that process, glycogen phosphorylase plays a pivotal role as an enzyme for glycogenolysis. Because ulcerative colitis (UC) is a long-term condition in which the colon and rectum become inflamed, patients with the disease might have high levels of protein or activity of glycogen phosphorylase (PYGL) in the blood. Therefore, this study aims to identify the protein level and activity of PYGL in the serum and peripheral blood mononuclear cells (PBMC) of ulcerative colitis patients.

Methods

After blood from UC patients was provided by Daejeon St. Mary's Hospital, the PBMCs were isolated using Leucosep tube pre-filled with separation medium (Greiner bio-one, 163288), and the serum was isolated by centrifugation at 1000 x g for 10 minutes in a refrigerated centrifuge (Labogene, 1248R). The PBMCs were stored in an LN2 cell storage tank (ICBiomedical, LS6000), and the serum was stored in a deep freezer (Nihon freezer, CLN-52UW) at -80°C until samples of 60 patients were gathered. To compare with UC patients, normal human PBMCs (STEMCELL Technologies, 70025.1) were used.

PYGL levels in serum and PBMCs from normal and UC patients were measured using Human PYGL ELISA Kit (Colorimetric) (Novus, NBP2-82520).

PYGL activity in serum and PBMCs from normal and UC patients were measured using Glycogen phosphorylase activity assay kit (Colorimetric) (Abcam, ab273271).

Activity Vmax and level from serum and PBMCs were analyzed using an unpaired t-test to determine significant differences (p &lt; 0.05), fitting the standard. Activity reaction curve from serum and PBMCs was anlyzed using an mutiple unpaired t-test to determine significant differences (q &lt; 0.05). GraphPad Prism 10 software was used for all analysis and the data were presented as Mean and SEM.

Results

Significant differences in PYGL activity were observed between UC patients and healthy controls in both serum and PBMC samples, though PYGL levels did not exhibit notable variation. These findings support the hypothesis that PYGL activity is linked to UC pathology and may serve as a marker for disease severity and progression.

Conclusion

This study provides initial evidence that PYGL activity could be a predictive biomarker and therapeutic target in UC. Future studies are warranted to further elucidate its role and assess the potential of PYGL inhibitors as a treatment strategy for autoimmune and inflammatory conditions like UC.

References

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Ma J, Wei K, Liu J et al. Glycogen metabolism regulates macrophage-mediated acute inflammatory responses. Nat Commun. 2020 Apr 14;11(1):1769.

Roach PJ, Depaoli-Roach AA, Hurley TD, Tagliabracci VS. Glycogen and its metabolism: some new developments and old themes. Biochem J. 2012 Feb 1;441(3):763-87.

Thwe PM, Pelgrom LR, Cooper R et al. Cell-Intrinsic Glycogen Metabolism Supports Early Glycolytic Reprogramming Required for Dendritic Cell Immune Responses. Cell Metab. 2019 Jul 2;30(1):225.