FSTL1 promotes liver fibrosis by reprogramming macrophage function through modulating the intracellular function of PKM2

Objective Follistatin-like protein 1 (FSTL1) is widely recognised as a secreted glycoprotein, but its role in modulating macrophage-related inflammation during liver fibrosis has not been documented. Herein, we aimed to characterise the roles of macrophage FSTL1 in the development of liver fibrosis. Design Expression analysis was conducted with human liver samples obtained from 33 patients with liver fibrosis and 18 individuals without fibrosis serving as controls. Myeloid-specific FSTL1-knockout (FSTL1M-KO) mice were constructed to explore the function and mechanism of macrophage FSTL1 in 3 murine models of liver fibrosis induced by carbon tetrachloride injection, bile duct ligation or a methionine-deficient and choline-deficient diet. Results FSTL1 expression was significantly elevated in macrophages from fibrotic livers of both humans and mice. Myeloid-specific FSTL1 deficiency effectively attenuated the progression of liver fibrosis. In FSTL1M-KO mice, the microenvironment that developed during liver fibrosis showed relatively less inflammation, as demonstrated by attenuated infiltration of monocytes/macrophages and neutrophils and decreased expression of proinflammatory factors. FSTL1M-KO macrophages exhibited suppressed proinflammatory M1 polarisation and nuclear factor kappa B pathway activation in vivo and in vitro. Furthermore, this study showed that, through its FK domain, FSTL1 bound directly to the pyruvate kinase M2 (PKM2). Interestingly, FSTL1 promoted PKM2 phosphorylation and nuclear translocation, reduced PKM2 ubiquitination to enhance PKM2-dependent glycolysis and increased M1 polarisation. Pharmacological activation of PKM2 (DASA-58) partially countered FSTL1-mediated glycolysis and inflammation. Conclusion Macrophage FSTL1 promotes the progression of liver fibrosis by inducing M1 polarisation and inflammation based on the intracellular PKM2 reprogramming function of macrophages.

[1]  Y. Liu,et al.  FSTL1 aggravates cigarette smoke-induced airway inflammation and airway remodeling by regulating autophagy , 2020, BMC Pulmonary Medicine.

[2]  Jie-shou Li,et al.  Follistatin like protein-1 modulates macrophage polarization and aggravates dextran sodium sulfate-induced colitis. , 2020, International immunopharmacology.

[3]  Fangfang Zhou,et al.  The function and clinical application of extracellular vesicles in innate immune regulation , 2020, Cellular & Molecular Immunology.

[4]  T. Vanhaecke,et al.  Robustness testing and optimization of an adverse outcome pathway on cholestatic liver injury , 2020, Archives of Toxicology.

[5]  T. Vanhaecke,et al.  Robustness testing and optimization of an adverse outcome pathway on cholestatic liver injury , 2020, Archives of Toxicology.

[6]  Tao Xu,et al.  PKM2 suppresses osteogenesis and facilitates adipogenesis by regulating β-catenin signaling and mitochondrial fusion and fission , 2020, Aging.

[7]  J. Alcorn,et al.  FSTL-1 Attenuation Causes Spontaneous Smoke-Resistant Pulmonary Emphysema , 2020 .

[8]  P. Doevendans,et al.  Follistatin-like 1 in Cardiovascular Disease and Inflammation. , 2019, Mini reviews in medicinal chemistry.

[9]  C. Ponting,et al.  Resolving the fibrotic niche of human liver cirrhosis at single cell level , 2019, Nature.

[10]  Dong-liang Fang,et al.  The glycoprotein follistatin-like 1 promotes brown adipose thermogenesis. , 2019, Metabolism: clinical and experimental.

[11]  W. Ning,et al.  Structural and functional study of FK domain of Fstl1 , 2019, Protein science : a publication of the Protein Society.

[12]  M. Pinzani,et al.  Liver fibrosis: Pathophysiology, pathogenetic targets and clinical issues. , 2019, Molecular aspects of medicine.

[13]  K. Schroder,et al.  Hepatic expression profiling identifies steatosis-independent and steatosis-driven advanced fibrosis genes. , 2018, JCI insight.

[14]  M. V. D. van den Hoff,et al.  Follistatin-like 1 in development and human diseases , 2018, Cellular and Molecular Life Sciences.

[15]  F. Recchia,et al.  Acute and Chronic Increases of Circulating FSTL1 Normalize Energy Substrate Metabolism in Pacing-Induced Heart Failure , 2018, Circulation. Heart failure.

[16]  J. Ladero,et al.  Liver fibrosis. , 2018, The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology.

[17]  W. Ning,et al.  TGF-β1 induces Fstl1 via the Smad3-c-Jun pathway in lung fibroblasts. , 2017, American journal of physiology. Lung cellular and molecular physiology.

[18]  D. Broide,et al.  Autophagy plays a role in FSTL1-induced epithelial mesenchymal transition and airway remodeling in asthma. , 2017, American journal of physiology. Lung cellular and molecular physiology.

[19]  S. Friedman,et al.  Mechanisms of hepatic stellate cell activation , 2017, Nature Reviews Gastroenterology &Hepatology.

[20]  Y. Koyama,et al.  Liver inflammation and fibrosis. , 2017, The Journal of clinical investigation.

[21]  T. Jacks,et al.  PKM2, cancer metabolism, and the road ahead , 2016, EMBO reports.

[22]  L. O’Neill,et al.  Metabolic reprogramming in macrophages and dendritic cells in innate immunity , 2015, Cell Research.

[23]  Ping Wang,et al.  Structural insight into mechanisms for dynamic regulation of PKM2 , 2015, Protein & Cell.

[24]  Y. Geng,et al.  Blocking follistatin-like 1 attenuates bleomycin-induced pulmonary fibrosis in mice , 2015, The Journal of experimental medicine.

[25]  Susan R. Quinn,et al.  Pyruvate kinase M2 regulates Hif-1α activity and IL-1β induction and is a critical determinant of the warburg effect in LPS-activated macrophages. , 2015, Cell metabolism.

[26]  Mohsen Naghavi,et al.  Liver cirrhosis mortality in 187 countries between 1980 and 2010: a systematic analysis , 2014, BMC Medicine.

[27]  Haichao Wang,et al.  PKM2 Regulates the Warburg Effect and Promotes HMGB1 Release in Sepsis , 2014, Nature Communications.

[28]  B. Hostager,et al.  Follistatin-like protein 1 and its role in inflammation and inflammatory diseases , 2014, Immunologic research.

[29]  Frank Tacke,et al.  Macrophage heterogeneity in liver injury and fibrosis. , 2014, Journal of hepatology.

[30]  J. Kellum,et al.  Follistatin‐like protein 1 enhances NLRP3 inflammasome‐mediated IL‐1β secretion from monocytes and macrophages , 2014, European journal of immunology.

[31]  Alberto Mantovani,et al.  Macrophage plasticity and polarization in liver homeostasis and pathology , 2014, Hepatology.

[32]  J. Fallowfield,et al.  Liver fibrosis and repair: immune regulation of wound healing in a solid organ , 2014, Nature Reviews Immunology.

[33]  R. Schwabe,et al.  Hepatic macrophages but not dendritic cells contribute to liver fibrosis by promoting the survival of activated hepatic stellate cells in mice , 2013, Hepatology.

[34]  Liang Zheng,et al.  Succinate is an inflammatory signal that induces IL-1β through HIF-1α , 2013, Nature.

[35]  K. Aldape,et al.  ERK1/2-dependent phosphorylation and nuclear translocation of PKM2 promotes the Warburg effect , 2012, Nature Cell Biology.

[36]  Christian M. Metallo,et al.  Pyruvate kinase M2 activators promote tetramer formation and suppress tumorigenesis , 2012, Nature chemical biology.

[37]  Zheng Zhang,et al.  Liver fibrosis: mechanisms of immune-mediated liver injury , 2011, Cellular and Molecular Immunology.

[38]  Matthew K. Knabel,et al.  Pyruvate Kinase M2 Is a PHD3-Stimulated Coactivator for Hypoxia-Inducible Factor 1 , 2011, Cell.

[39]  Ye Guang Chen,et al.  Follistatin-like 1 (Fstl1) is a bone morphogenetic protein (BMP) 4 signaling antagonist in controlling mouse lung development , 2011, Proceedings of the National Academy of Sciences.

[40]  Dawei Li,et al.  Follistatin-like protein 1 is elevated in systemic autoimmune diseases and correlated with disease activity in patients with rheumatoid arthritis , 2011, Arthritis Research & Therapy.

[41]  S. Friedman,et al.  Pathogenesis of liver fibrosis. , 2011, Annual review of pathology.

[42]  D. Brenner,et al.  Toll-like receptor 9 promotes steatohepatitis by induction of interleukin-1beta in mice. , 2010, Gastroenterology.

[43]  Yosuke Osawa,et al.  TLR4 enhances TGF-β signaling and hepatic fibrosis , 2007, Nature Medicine.

[44]  D. Brenner,et al.  The role of TGFbeta1 in initiating hepatic stellate cell activation in vivo. , 1999, Journal of hepatology.

[45]  J. Iredale,et al.  Pathogenesis of liver fibrosis. , 1997, Clinical science.

[46]  A. B. Sukhomlinov,et al.  [Liver cirrhosis]. , 1989, Fel'dsher i akusherka.