Role of Chitinase 3-Like 1 Protein in the Pathogenesis of Hepatic Insulin Resistance in Nonalcoholic Fatty Liver Disease

YKL-40, cardiovascular events, and mortality in individuals recently diagnosed with type 2 diabetes: A Danish cohort study

AIMS

We investigated the association of the inflammatory biomarker YKL-40 with cardiovascular events (CVEs) and mortality in individuals with type 2 diabetes.

METHODS

We followed 11,346 individuals recently diagnosed with type 2 diabetes for up to 14 years. Baseline YKL-40 levels (measured in 9,010 individuals) were grouped into percentiles (0-33 %, 34-66 %, 67-90 %, and 91-100 %) and analyzed continuously (per 1 SD log increment), with comparisons to CRP (measured in 9,644 individuals). Cox regression assessed associations with atrial fibrillation (AF), ischemic stroke (IS), venous thromboembolism (VTE), myocardial infarction (MI), heart failure (HF), peripheral artery disease (PAD), and all-cause, cardiovascular, and cancer mortality.

RESULTS

Adjusted HRs (95% CIs) for the highest (91-100%) versus the lowest (0-33%) YKL-40 percentile category were 1.31 (1.04-1.66) for AF, 1.43 (0.98-2.07) for IS, 1.07 (0.65-1.76) VTE, 0.88 (0.52-1.48) for MI, 1.66 (1.19-2.31) for HF, 1.66 (1.12-2.48) for PAD, and 2.18 (1.85-2.56) for all-cause, 1.64 (1.07-2.50) for cardiovascular, and 2.73 (2.05-3.63) for cancer mortality. Each 1 SD log increase in YKL-40 and CRP levels similarly increased CVE risks, with CRP being superior for MI and cardiovascular mortality.

CONCLUSIONS

YKL-40 is a prognostic biomarker for most CVEs, and even more so for all-cause mortality, primarily driven by cancer-related causes.

Inflammatory Effects and Regulatory Mechanisms of Chitinase-3-like-1 in Multiple Human Body Systems: A Comprehensive Review

Chitinase-3-like-1 (Chi3l1), also known as YKL-40 or BRP-39, is a highly conserved mammalian chitinase with a chitin-binding ability but no chitinase enzymatic activity. Chi3l1 is secreted by various cell types and induced by several inflammatory cytokines. It can mediate a series of cell biological processes, such as proliferation, apoptosis, migration, differentiation, and polarization. Accumulating evidence has verified that Chi3l1 is involved in diverse inflammatory conditions; however, a systematic and comprehensive understanding of the roles and mechanisms of Chi3l1 in almost all human body system-related inflammatory diseases is still lacking. The human body consists of ten organ systems, which are combinations of multiple organs that perform one or more physiological functions. Abnormalities in these human systems can trigger a series of inflammatory environments, posing serious threats to the quality of life and lifespan of humans. Therefore, exploring novel and reliable biomarkers for these diseases is highly important, with Chi3l1 being one such parameter because of its physiological and pathophysiological roles in the development of multiple inflammatory diseases. Reportedly, Chi3l1 plays an important role in diagnosing and determining disease activity/severity/prognosis related to multiple human body system inflammation disorders. Additionally, many studies have revealed the influencing factors and regulatory mechanisms (e.g., the ERK and MAPK pathways) of Chi3l1 in these inflammatory conditions, identifying potential novel therapeutic targets for these diseases. In this review, we comprehensively summarize the potential roles and underlying mechanisms of Chi3l1 in inflammatory disorders of the respiratory, digestive, circulatory, nervous, urinary, endocrine, skeletal, muscular, and reproductive systems, which provides a more systematic understanding of Chi3l1 in multiple human body system-related inflammatory diseases. Moreover, this article summarizes potential therapeutic strategies for inflammatory diseases in these systems on the basis of the revealed roles and mechanisms mediated by Chi3l1.

Identification and functional analysis of genes mediating osteoclast-driven progression of osteoporosis

OBJECTIVE

The pathological mechanism of osteoporosis (OP) involves increased bone resorption mediated by osteoclasts and decreased bone formation mediated by osteoblasts, leading to an imbalance in bone homeostasis. Identifying key molecules in osteoclast-mediated OP progression is crucial for the prevention and treatment of OP.

METHODS

Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were performed on the OP patient datasets from the GEO database. The results were intersected with the differential expression results from the osteoclast differentiation dataset to identify key genes. These key genes were then subjected to disease relevance analysis, and consensus clustering was performed on OP patient samples based on their expression profiles. The subgroups were analyzed for differences, followed by GO, KEGG, GSEA, and GSVA analyses, and immune infiltration. Finally, osteoclast differentiation model was constructed. After validating the success of the model using TRAP and F-actin staining, the differential expression of key genes was validated in vitro via Western blot.

RESULTS

CTRL, ARHGEF5, PPAP2C, VSIG2, and PBLD were identified as key genes. These genes exhibited strong disease relevance (AUC > 0.9). Functional enrichment results also indicated their close association with OP and osteoclast differentiation. In vitro differential expression validation showed that during osteoclast differentiation, CTRL was downregulated, while ARHGEF5, PPAP2C, VSIG2, and PBLD were upregulated, with all differences being statistically significant (P < 0.05).

DISCUSSION

Currently, there are no studies on the effects of these five genes on osteoclast differentiation. Therefore, it is meaningful to design in vivo and in vitro perturbation experiments to observe the impact of each gene on osteoclast differentiation and OP progression.

CONCLUSION

CTRL, ARHGEF5, PPAP2C, VSIG2, and PBLD show high potential as molecular targets for basic and clinical research in osteoclast-mediated OP.

Chitinase-3 like-protein-1, a prognostic biomarker in patients with hepatocellular carcinoma and concomitant myosteatosis

BACKGROUND

Chitinase-3 like-protein-1 (CHI3L1) is a member of the mammalian chitinase-like proteins and elevated serum CHI3L1 level has been proved to be associated with poor prognosis in hepatocellular carcinoma (HCC). This study aimed to investigate the relationship between serum CHI3L1 levels and body composition parameters in patients with HCC after liver transplantation (LT).

METHODS

This retrospective study enrolled 200 patients after LT for HCC. Blood samples were collected and serum concentrations of CHI3L1 were measured by enzyme-linked immunosorbent assay. Computer tomography (CT) were used to estimate skeletal muscle and adipose tissue mass. Spearman's rank correlation test was performed to assess associations between serum CHI3L1 levels and these body composition parameters. A Cox proportional-hazards regression model was performed to identify independent prognostic factors. Overall survival (OS) and recurrence-free survival (RFS) curves were constructed using the Kaplan-Meier method and compared by the log-rank test.

RESULTS

Total 71 patients (35.5%) were diagnosed with myosteatosis according to skeletal muscle radiation attenuation (SMRA). The 5-year OS rates were 66.9% in non-myosteatosis group, significantly higher than 49.5% in myosteatosis group (p = 0.025), while the RFS of myosteatosis group (5-year RFS: 52.6%) or non-myosteatosis group (5-year RFS: 42.0%) shown no significant difference (p = 0.068). The serum CHI3L1 level were significantly negative correlated with SMRA (r = -0.3, p < 0.001). Interestingly, in patients with myosteatosis, Kaplan-Meier analysis revealed that elevated serum CHI3L1 levels were associated with worse OS (p < 0.001) and RFS (p = 0.047). However, in patients without myosteatosis, Kaplan-Meier analysis found elevated serum CHI3L1 levels were not associated with OS (p = 0.070) or RFS (p = 0.104).

CONCLUSIONS

Elevated CHI3L1 was negatively correlated with SMRA, and predicted poorer prognosis in Chinese population after LT for HCC, especially in those patients with concomitant myosteatosis. Monitoring serum CHI3L1 can predict prognosis and effectively guide individual nutrition intervention.

Association between chitinase-3-like protein 1 and metabolic-associated fatty liver disease in patients with type 2 diabetes mellitus

BACKGROUND AND AIM

Early identification of liver fibrosis is essential for the prognosis of metabolic-associated fatty liver disease (MAFLD), particularly in type 2 diabetes mellitus (T2DM) patients. Here, we explored the association of chitinase-3-like protein 1 (CHI3L1) and liver fibrosis in T2DM-MAFLD patients.

METHODS

Liver fibrosis was staged in T2DM-MAFLD patients, and a liver stiffness measurement (LSM) of ≥ 8 kPa was used to differentiate between non-significant (NSLF) and significant liver fibrosis (SLF) subgroups. The two subgroups were compared for serum CHI3L1 and other parameters. Linear correlation, logistic regression, and restricted cubic spline (RCS) analyses were performed to evaluate the association between CHI3L1 and liver fibrosis. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic accuracy of CHI3L1.

RESULTS

Among T2DM-MAFLD, SLF patients had higher CHI3L1 compared to NSLF patients. CHI3L1 was found to be positively correlated with LSM. Multivariate logistic regression analysis suggested that CHI3L1 may be a potential independent risk factor for SLF. Further stratified analysis indicated that the odds ratios of SLF in the high CHI3L1 group were higher than in the low CHI3L1 group in the subgroups. RCS analysis suggested an increasing trend in the incidence of significant fibrosis with the rising level of CHI3L1. The area under the ROC curve for detecting significant fibrosis was 0.749 (95% CI: 0.668-0.829).

CONCLUSIONS

Serum CHI3L1 demonstrates an association with significant liver fibrosis. High serum levels of CHI3L1 may indicate the existence of significant liver fibrosis in T2DM-MAFLD patients.

Uncovering novel mechanisms of chitinase-3-like protein 1 in driving inflammation-associated cancers

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein that is induced and regulated by multiple factors during inflammation in enteritis, pneumonia, asthma, arthritis, and other diseases. It is associated with the deterioration of the inflammatory environment in tissues with chronic inflammation caused by microbial infection or autoimmune diseases. The expression of CHI3L1 expression is upregulated in several malignant tumors, underscoring the crucial role of chronic inflammation in the initiation and progression of cancer. While the precise mechanism connecting inflammation and cancer is unclear, the involvement of CHI3L1 is involved in chronic inflammation, suggesting its role as a contributing factor to in the link between inflammation and cancer. CHI3L1 can aggravate DNA oxidative damage, induce the cancerous phenotype, promote the development of a tumor inflammatory environment and angiogenesis, inhibit immune cells, and promote cancer cell growth, invasion, and migration. Furthermore, it participates in the initiation of cancer progression and metastasis by binding with transmembrane receptors to mediate intracellular signal transduction. Based on the current research on CHI3L1, we explore introduce the receptors that interact with CHI3L1 along with the signaling pathways that may be triggered during chronic inflammation to enhance tumorigenesis and progression. In the last section of the article, we provide a brief overview of anti-inflammatory therapies that target CHI3L1.

Research advances in serum chitinase-3-like protein 1 in liver fibrosis

While liver fibrosis remains a serious, progressive, chronic liver disease, and factors causing damage persist, liver fibrosis may develop into cirrhosis and liver cancer. However, short-term liver fibrosis is reversible. Therefore, an early diagnosis of liver fibrosis in the reversible transition phase is important for effective treatment of liver diseases. Chitinase-3-like protein 1 (CHI3L1), an inflammatory response factor that participates in various biological processes and is abundant in liver tissue, holds promise as a potential biomarker for liver diseases. Here, we aimed to review research developments regarding serum CHI3L1 in relation to the pathophysiology and diagnosis of liver fibrosis of various etiologies, providing a reference for the diagnosis, treatment, and prognosis of liver diseases.

Serum YKL-40 in coronary heart disease: linkage with inflammatory cytokines, artery stenosis, and optimal cut-off value for estimating major adverse cardiovascular events

Objective

YKL-40, previously known as chitinase-3-like protein 1 (CHI3L1), is an inflammation-related glycoprotein that promotes atherosclerosis, but its application and optimal cut-off value as a prognostic biomarker in coronary heart disease (CHD) require more clinical evidence. Thus, this prospective study aimed to evaluate the linkage of serum YKL-40 with disease features, inflammatory cytokines, and major adverse cardiovascular events (MACEs) in CHD patients.

Methods

A total of 410 CHD patients were enrolled for serum YKL-40 determination via enzyme-linked immunosorbent assay. Meanwhile, serum YKL-40 levels in 100 healthy controls (HCs) were also quantified.

Results

YKL-40 level was higher in CHD patients compared with that in HCs (P < 0.001). YKL-40 was positively linked with hyperlipidemia (P = 0.014), diabetes mellitus (P = 0.001), fasting blood glucose (P = 0.045), C-reactive protein (P < 0.001), the Gensini score (P < 0.001), and stenosis degree (graded by the Gensini score) (P < 0.001) in CHD patients. In addition, an elevated YKL-40 level was associated with increased levels of tumor necrosis factor alpha (P = 0.001), interleukin (IL)-1β (P = 0.001), IL-6 (P < 0.001), and IL-17A (P = 0.002) in CHD patients. The 1-/2-/3-year cumulative MACE rates of CHD patients were 5.5%, 14.4%, and 25.0%, respectively. Regarding the prognostic capability, YKL-40 ≥100 ng/ml (the median cut-off value) (P = 0.003) and YKL-40 ≥150 ng/ml (the third interquartile cut-off value) (P = 0.021) reflected an elevated accumulating MACE rate, whereas accumulating MACE was not different between CHD patients with YKL-40 ≥80 and <80 ng/ml (the first interquartile cut-off value) (P = 0.083).

Conclusion

Serum YKL-40 is positively linked with inflammatory cytokines and the Gensini score, whose high expression cut-off by 100 and 150 ng/ml estimates a higher MACE risk in CHD patients.

Association of Non-Invasive Markers with Significant Fibrosis in Patients with Nonalcoholic Fatty Liver Disease: A Cross-Sectional Study

Purpose

The identification of significant fibrosis is critical for predicting the prognosis of non-alcoholic fatty liver disease (NAFLD). This study aimed to compare the predictive value of chitinase-3-like protein 1 (CHl3L1) and other non-invasive biomarkers, as well as to establish a novel non-invasive diagnostic model for assessing the risk of significant fibrosis in NAFLD.

Patients and Methods

A total of 71 patients with confirmed NAFLD based on liver biopsy were included in this study. Serum CHI3L1 levels and other non-invasive fibrosis assessment measures were determined. The aspartate aminotransferase-to-platelet ratio index (APRI) and Fibrosis-4 Index (FIB-4) were calculated to assess the diagnostic superiority of serum CHI3L1 compared to other non-invasive fibrosis assessment measures. Multivariate logistic regression analysis was conducted to identify relevant variables for constructing a diagnostic model. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of each index, including the area under ROC curve (AUC), sensitivity, and specificity. A nomogram was established based on the logistic regression model.

Results

Serum CHI3LI levels were found to be higher in NAFLD patients with significant fibrosis compared to those without significant fibrosis. Multivariate logistic regression analysis revealed that aspartate aminotransferase (AST), type IV collagen (IV-C), CHI3L1, and liver stiffness measurement (LSM) were identified as potential independent risk factors associated with significant fibrosis in patients. The AUC of CHI3L1 for diagnosing significant liver fibrosis was 0.716 (0.596,0.836), with the optimal cut-off point of 125.315. The nomogram incorporating CHI3LI, AST, IV-C, and LSM further improved the potential predictive value, with an AUC for diagnosing significant fibrosis of 0.864 (0.766,0.962). This was superior to IV-C, CHI3L1, LSM, and APRI (all p < 0.05).

Conclusion

The diagnostic model constructed by CHI3L1 combined with the existing non-invasive markers AST, IV-C, and LSM can help assess the risk of significant liver fibrosis in NAFLD.

Association of serum YKL-40 change with prognosis in acute ischemic stroke patients complicated with diabetes mellitus

Objective: This study intended to explore the serum YKL-40 change and its prognostic implication in acute ischemic stroke (AIS) patients with diabetes mellitus (DM). Methods: YKL-40 was detected from serum by ELISA in 121 AIS patients with DM at baseline, day (D)1, D3, D7 and D30 after disease onset. Results: YKL-40 increased from baseline to D3, then decreased until D30 (p < 0.001). Notably, 20.7% of patients had stroke recurrence, and 6.6% of patients died during follow-up. YKL-40 at D1 (p = 0.043), D7 (p = 0.007) and D30 (p = 0.001) predicted higher stroke recurrence risk; additionally, YKL-40 at D3 (p = 0.010), D7 (p = 0.007) and D30 (p = 0.002) estimated higher mortality risk. Conclusion: Serum YKL-40 has a prognostic effect on the management of AIS patients with DM.

Multi-omics profiling reveals Chitinase-3-like protein 1 as a key mediator in the crosstalk between sarcopenia and liver cancer

Sarcopenia is prevalent in patients with hepatocellular carcinoma (HCC), and can adversely affect their outcomes. This study aims to explore the key mechanisms in the crosstalk between sarcopenia and HCC based on multi-omics profiling. A total of 136 male patients with HCC were enrolled. Sarcopenia was an independent risk factor for poor outcomes after liver transplantation (p < 0.05). Inflammatory cytokine and metabolomic profiling on these patients identified elevated plasma sTNF-R1/CHI3L1 and dysregulated lipid metabolism as related to sarcopenia and tumor recurrence risk concurrently (p < 0.05). Integrated analysis revealed close relationship between CHI3L1 and fatty acid metabolism. In mouse cachectic models by intraperitoneal injection of H22 cells, CHI3L1 was significantly elevated in the atrophic muscle tissue, as well as in circulation. In-vitro, CHI3L1 was up-regulated in muscle cells to protect itself from inflammatory damage through TNF-α/TNF-R1 signaling. CHI3L1 secreted by the muscle cells promoted the invasion of co-cultured HCC cells. Tumor tissue transcriptome data for 73 out of the 136 patients revealed that CHI3L1 may regulate fatty acid metabolism and oxidative stress. In vitro, CHI3L1 caused ROS and lipid accumulation. Targeted lipid profiling further proved that CHI3L1 was able to activate arachidonic acid metabolism, leading to lipid peroxide (LPO) accumulation. Meanwhile, LPO inhibition could compromise the remarkable pro-cancerous effects of CHI3L1. In conclusion, sarcopenia adversely affects the outcomes of liver transplantation for HCC. In sarcopenic patients, CHI3L1 was up-regulated and secreted by the skeletal muscle to protect itself through TNF-α/TNF-R1 signaling, which, in turn, can promote HCC tumor progression by inducing LPO accumulation.

Identification of Shared Gene Signatures in Different Stages of Nonalcoholic Fatty Liver Disease Using Integrated Microarray Datasets

Background: Nonalcoholic fatty liver disease (NAFLD) is the most common type of chronic liver disease worldwide. Left untreated, it can be a risk factor for developing cirrhosis or hepatocellular carcinoma (HCC). Although experts have made many efforts to find the underlying mechanisms of NAFLD, they remain a mystery. Objectives: This study aimed to distinguish common gene signatures and pathways in the human liver during NAFLD progression through systems biology. Methods: In this study, the researchers selected three microarray datasets, GSE48452, GSE63067, and GSE89632, from the NCBI GEO database to explore differentially expressed genes (DEGs) among healthy controls, simple steatosis, and nonalcoholic steatohepatitis (NASH) patients. Furthermore, protein-protein interaction (PPI) networks and pathway enrichment analyses were used to detect common genes and biological pathways in different stages of NAFLD. Results: The current study included 45 healthy participants, 36 simple steatosis patients, and 46 NASH patients. Common genes for NAFLD progression were Chi3L1, ICAM1, MT1A, MT1H, ABCB11, ACOT1, CYP2C9, HSP90B1, and CPB2, which are involved in inflammation and oxidative stress pathways. Conclusions: The present study investigated the shared vital genes and pathways between different stages of NAFLD, which may facilitate understanding NAFLD mechanisms and identifying potential therapeutic targets in this disease.

Serum CHI3L1 as a diagnostic marker and risk factor for liver fibrosis in HBeAg-negative chronic hepatitis B

Chronic hepatitis B (CHB) as the major inducement of hepatocellular carcinoma and cirrhosis, imposes a heavy health burden upon patients. This research aims to investigate the diagnostic value of serum chitinase 3-like 1 (CHI3L1) in hepatitis B e antigen (HBeAg)-negative CHB liver fibrosis (LF) and to analyze the risk factors. We selected 78 patients with HBeAg-negative CHB admitted to our hospital between October 2018 and October 2019, and grouped them (F_0,1 group, n=38; F_2-4 group, n=40) based on their stages evaluated by the METAVIR scoring system. Cubital venous blood was collected from patients in both groups to quantify the content of CHI3L1 after serum extraction. The correlation of CHI3L1 in CHB with LF diagnostic markers fibrosis 4 (FIB-4) and γ-glutamyltranspeptidase (GGT) to platelet (PLT) ratio (GPR) as well as LF staging was analyzed. The diagnostic value of serum CHI3L1 in HBeAg-negative CHB fibrosis staging was analyzed by receiver operating characteristic (ROC) curve, and the multivariate analysis of the risk factors for FB in HBeAg-negative CHB patients was performed using the Logistic regression model. This study found that serum CHI3L1 was positively correlated not only with LF markers (FIB-4, GPR), but also with LF staging. Serum CHI3L1 had high diagnostic efficiency for LF staging, with the sensitivity and specificity of 80.00% and 71.05%, respectively. In addition, CHI3L1, FIB-4, and GPR were identified to be the risk factors for LF in HBeAg-negative CHB. In conclusion, serum CHI3L1 can be used as a diagnostic marker and risk factor for LF in patients with HBeAg-negative CHB.

Tim-1 Deficiency Aggravates High-Fat Diet-Induced Steatohepatitis in Mice

Non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) is commonly associated with obesity and characterized by excessive lipid accumulation and liver inflammation. The T cell immunoglobulin and mucin domain 1 (Tim-1), also known as hepatitis A virus cellular receptor 1 (Havcr-1) and kidney injury molecule 1 (Kim-1), has been shown to affect innate immunity-driven proinflammatory cascade in liver ischemia-reperfusion injury. However, its contribution to obesity-related NAFLD/NASH remains unknown. Thus, this study was designed to evaluate the role of Tim-1 in obesity-related liver inflammation and injury in wild-type (WT) and Tim-1-deficient (Tim-1^-/-) C57BL/6J mice fed a high-fat diet (HFD) for 5-6 months. HFD feeding induced steatosis and upregulated Tim-1 gene expression in the liver of WT mice. Surprisingly, Tim-1^-/- mice on HFD diet exhibited an exacerbation of hepatic steatosis, accompanied with an elevation of protein levels of fatty acid translocase CD36 and sterol regulatory element binding protein 1 (SREBP1). Tim-1 deficiency also enhanced HFD-induced liver inflammation and injury, as evidenced by augmented increase in hepatic expression of pro-inflammatory factor lipocalin 2 and elevated serum alanine transaminase (ALT). In addition, gene expression of type I, III and IV collagens and liver fibrosis were greatly enhanced in HFD Tim-1^-/- mice compared with HFD WT mice. HFD-induced hepatic expression of YM-1, a specific mouse M2 macrophage marker, was further upregulated by deletion of Tim-1. Together, these results show that Tim-1 deficiency aggravates the effects of HFD diet on lipid accumulation and liver fibrosis, most likely through enhanced infiltration and activation of inflammatory cells.

Chitinase 3-like-1 contributes to acetaminophen-induced liver injury by promoting hepatic platelet recruitment

Background

Hepatic platelet accumulation contributes to acetaminophen (APAP)-induced liver injury (AILI). However, little is known about the molecular pathways involved in platelet recruitment to the liver and whether targeting such pathways could attenuate AILI.

Methods

Mice were fasted overnight before intraperitoneally (i.p.) injected with APAP at a dose of 210 mg/kg for male mice and 325 mg/kg for female mice. Platelets adherent to Kupffer cells were determined in both mice and patients overdosed with APAP. The impact of α-chitinase 3-like-1 (α-Chi3l1) on alleviation of AILI was determined in a therapeutic setting, and liver injury was analyzed.

Results

The present study unveiled a critical role of Chi3l1 in hepatic platelet recruitment during AILI. Increased Chi3l1 and platelets in the liver were observed in patients and mice overdosed with APAP. Compared to wild-type (WT) mice, Chil1-/- mice developed attenuated AILI with markedly reduced hepatic platelet accumulation. Mechanistic studies revealed that Chi3l1 signaled through CD44 on macrophages to induce podoplanin expression, which mediated platelet recruitment through C-type lectin-like receptor 2. Moreover, APAP treatment of Cd44-/- mice resulted in much lower numbers of hepatic platelets and liver injury than WT mice, a phenotype similar to that in Chil1-/- mice. Recombinant Chi3l1 could restore hepatic platelet accumulation and AILI in Chil1-/- mice, but not in Cd44-/- mice. Importantly, we generated anti-Chi3l1 monoclonal antibodies and demonstrated that they could effectively inhibit hepatic platelet accumulation and AILI.

Conclusions

We uncovered the Chi3l1/CD44 axis as a critical pathway mediating APAP-induced hepatic platelet recruitment and tissue injury. We demonstrated the feasibility and potential of targeting Chi3l1 to treat AILI.

Funding

ZS received funding from NSFC (32071129). FWL received funding from NIH (GM123261). ALFSG received funding from NIDDK (DK 058369). ZA received funding from CPRIT (RP150551 and RP190561) and the Welch Foundation (AU-0042-20030616). CJ received funding from NIH (DK122708, DK109574, DK121330, and DK122796) and support from a University of Texas System Translational STARs award. Portions of this work were supported with resources and the use of facilities of the Michael E. DeBakey VA Medical Center and funding from Department of Veterans Affairs I01 BX002551 (Equipment, Personnel, Supplies). The contents do not represent the views of the US Department of Veterans Affairs or the US Government.