Inflammation-Related Factors S100A9 and TLR2 in Cardiomyocyte Hypertrophy

Abstract

Objective

The pathogenesis and progression of heart failure (HF) are governed by complex, interconnected biological pathways, with dysregulated immune responses and maladaptive cardiac remodeling playing central roles. Although specific inflammatory mediators have been implicated in modulating critical features of cardiac remodeling—such as cardiomyocyte hypertrophy and extracellular matrix fibrosis—the precise molecular mechanisms driving these processes remain incompletely characterized.

Methods

Integrated bioinformatics analysis of HF and hypertrophic cardiomyopathy (HCM) transcriptomic datasets identified pathologically relevant candidate genes. A protein-protein interaction (PPI) network was constructed from these candidates using the STRING database, followed by module analysis. Serum S100 calcium-binding protein A9 (S100A9) protein expression in HF patients was quantified by Western blotting under reducing conditions. The functional relevance of prioritized genes was subsequently validated through: (i) in vitro cyclic mechanical stretch in primary neonatal rat cardiomyocytes, and (ii) in vivo pressure overload modeling via transverse aortic constriction (TAC) in mice.

Results

Bioinformatics analysis of HF and HCM datasets revealed a significant association between immune function and cardiac remodeling. Using CytoNCA, we identified core genes, among which the top 25 included multiple inflammatory pathway-related factors, such as S100A9 and Toll-like receptor 2 (TLR2). Notably, S100A9 levels were significantly elevated in the serum of HF patients and in mechanically stretched cardiomyocytes. This increase correlated with upregulated expression of hypertrophy-related markers, including atrial natriuretic peptide (ANP). Furthermore, mechanical stretch-induced S100A9 upregulation markedly enhanced TLR2 expression in cardiomyocytes. Importantly, TLR2 inhibition substantially attenuated the mechanical stretch-induced upregulation of S100A9 mRNA expression, as well as the subsequent hypertrophic and inflammatory responses in cardiomyocytes.

Conclusion

The inflammatory mediators S100A9 and TLR2 engage in reciprocal activation that amplifies the hypertrophic response in mechanically stretched cardiomyocytes. This pathogenic cross-talk exacerbates maladaptive remodeling and likely accelerates HF progression.

Keywords

S100 calcium-binding protein A9 / Toll-like receptor 2 / Cardiomyocyte hepertrophy / Heart failure / Mechanical stretch / Inflammatory response / Transverse aortic constriction / Reciprocal activation

References

[1] BazgirF. The Microenvironment of the Pathogenesis of Cardiac Hypertrophy. Cells, 2023, 12131780.

[2] ChenF. Advances in the study of S100A9 in cardiovascular diseases. Cell prolif, 2024, 2024e13636.

[3] LuH. Engineered Macrophage Membrane-Coated S100A9-siRNA for Ameliorating Myocardial Ischemia-Reperfusion Injury. Adv Sci (Weinh), 2024, 1141e2403542.

[4] LiY, ChenB, YangX, et al.. S100a8/a9 Signaling Causes Mitochondrial Dysfunction and Cardiomyocyte Death in Response to Ischemic/Reperfusion Injury. Circulation., 2019, 140(9): 751-764.

[5] SreejitG, Abdel-LatifA, AthmanathanB, et al.. Neutrophil-Derived S100A8/A9 Amplify Granulopoiesis After Myocardial Infarction. Circulation., 2020, 141(13): 1080-1094.

[6] YuanYP, ShenZY, TengT, et al.. S100a8/9 (S100 Calcium Binding Protein a8/9) Promotes Cardiac Hypertrophy Via Upregulation of FGF23 (Fibroblast Growth Factor 23) in Mice. Journal of the American Heart Association., 2024, 1310. e028006

[7] ArslanF, KeoghB, McGuirkP, et al.. TLR2 and TLR4 in ischemia reperfusion injury. Mediators of inflammation., 2010, 2010. 704202

[8] QianJ, LiangS, WangQ, et al.. Toll-like receptor-2 in cardiomyocytes and macrophages mediates isoproterenol-induced cardiac inflammation and remodeling. FASEB journal : official publication of the Federation of American Societies for Experimental Biology., 2023, 372. e22740

[9] ChaoW. Toll-like receptor signaling: a critical modulator of cell survival and ischemic injury in the heart. American journal of physiology Heart and circulatory physiology., 2009, 296(1): H1-12.

[10] ZhangXY, HuangZ, LiQJ, et al.. Ischemic postconditioning attenuates the inflammatory response in ischemia/reperfusion myocardium by upregulating miR-499 and inhibiting TLR2 activation. Molecular medicine reports., 2020, 22(1): 209-218.

[11] FerenčićA, CuculićD, StembergaV, et al.. Left ventricular hypertrophy is associated with overexpression of HSP60, TLR2, and TLR4 in the myocardium. Scandinavian journal of clinical and laboratory investigation., 2020, 80(3): 236-246.

[12] YeS, LinK, WuG, et al.. Toll-like receptor 2 signaling deficiency in cardiac cells ameliorates Ang II-induced cardiac inflammation and remodeling. Translational research : the journal of laboratory and clinical medicine., 2021, 233: 62-76.

[13] MathurS, WalleyKR, WangY, et al.. Extracellular heat shock protein 70 induces cardiomyocyte inflammation and contractile dysfunction via TLR2. Circulation journal : official journal of the Japanese Circulation Society., 2011, 75(10): 2445-2452.

[14] LiuP, BaoHY, JinCC, et al.. Targeting Extracellular Heat Shock Protein 70 Ameliorates Doxorubicin-Induced Heart Failure Through Resolution of Toll-Like Receptor 2-Mediated Myocardial Inflammation. Journal of the American Heart Association., 2019, 820. e012338

[15] HigashikuniY, TanakaK, KatoM, et al.. Toll-like receptor-2 mediates adaptive cardiac hypertrophy in response to pressure overload through interleukin-1β upregulation via nuclear factor κB activation. Journal of the American Heart Association., 2013, 26. e000267

[16] WuRN, YuTY, ZhouJC, et al.. Targeting HMGB1 ameliorates cardiac fibrosis through restoring TLR2-mediated autophagy suppression in myocardial fibroblasts. International journal of cardiology., 2018, 267: 156-162.

[17] QianJ, WangQ, XuJ, et al.. Macrophage OTUD1-CARD9 axis drives isoproterenol-induced inflammatory heart remodelling. Clinical and translational medicine., 2024, 148. e1790

[18] FengL, LiG, AnJ, et al.. Exercise Training Protects Against Heart Failure Via Expansion of Myeloid-Derived Suppressor Cells Through Regulating IL-10/STAT3/S100A9 Pathway. Circulation Heart failure., 2022, 153. e008550

[19] LuoX, WangR, ZhangX, et al.. Identification CCL2,CXCR2,S100A9 of the immune-related gene markers and immune infiltration characteristics of inflammatory bowel disease and heart failure via bioinformatics analysis and machine learning. Frontiers in cardiovascular medicine., 2023, 101268675.

[20] Hong L, Cai X, Zhan Y, et al. TLR2 activates AP-1 to facilitate CTGF transcription and stimulate doxorubicin-induced myocardial injury. Br J Pharmacol. 2025;46(3):606–617.

[21] PanL, YinC, JinKJ, et al.. Low-density lipoprotein receptor-related protein 6 ameliorates cardiac hypertrophy by regulating CTSD/HSP90α signaling during pressure overload. Acta pharmacologica Sinica., 2025, 46(3): 606-617.

[22] Kumar S, Wang G, Zheng N, et al. HIMF (Hypoxia-Induced Mitogenic Factor)-IL (Interleukin)-6 Signaling Mediates Cardiomyocyte-Fibroblast Crosstalk to Promote Cardiac Hypertrophy and Fibrosis. Hypertension. 2019;73(5):1058–1070.

[23] Wei X, Wu B, Zhao J, et al. Myocardial Hypertrophic Preconditioning Attenuates Cardiomyocyte Hypertrophy and Slows Progression to Heart Failure Through Upregulation of S100A8/A9. Circulation. 2015;131(17):1506–1517.

[24] MarinkovićG, KoenisDS, de CampL, et al.. S100A9 Links Inflammation and Repair in Myocardial Infarction. Circ Res., 2020, 127(5): 664-676.

[25] ZhaiY, AoL, YaoQ, et al.. Elevated Expression of TLR2 in Aging Hearts Exacerbates Cardiac Inflammatory Response and Adverse Remodeling Following Ischemia and Reperfusion Injury. Frontiers in immunology., 2022, 13. 891570

[26] MolesA, MurphyL, WilsonCL, et al.. A TLR2/S100A9/CXCL-2 signaling network is necessary for neutrophil recruitment in acute and chronic liver injury in the mouse. Journal of hepatology., 2014, 60(4): 782-791.

[27] MarinkovićG, Grauen LarsenH, YndigegnT, et al.. Inhibition of pro-inflammatory myeloid cell responses by short-term S100A9 blockade improves cardiac function after myocardial infarction. European heart journal., 2019, 40(32): 2713-2723.

[28] BaiB, XuY, ChenH. Pathogenic roles of neutrophil-derived alarmins (S100A8/A9) in heart failure: From molecular mechanisms to therapeutic insights. British journal of pharmacology., 2023, 180(5): 573-588.

[29] De LucaG, GoetteNP, LevPR, et al.. Elevated levels of damage-associated molecular patterns HMGB1 and S100A8/A9 coupled with toll-like receptor-triggered monocyte activation are associated with inflammation in patients with myelofibrosis. Frontiers in immunology., 2024, 151365015.

Funding

the National Natural Science Foundation of China(82370255)

Shanghai Science and Technology Commission Project(23410761200)

RIGHTS & PERMISSIONS

The Author(s), under exclusive licence to Huazhong University of Science and Technology