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.

[Role and mechanisms of CHI3L1 in coronary artery lesions in a mouse model of Kawasaki disease-like vasculitis]

OBJECTIVES

To explore the role and potential mechanisms of chitinase-3-like protein 1 (CHI3L1) in coronary artery lesions in a mouse model of Kawasaki disease (KD)-like vasculitis.

METHODS

Four-week-old male SPF-grade C57BL/6 mice were randomly divided into a control group and a model group, with 10 mice in each group. The model group mice were intraperitoneally injected with 0.5 mL of lactobacillus casei cell wall extract (LCWE) to establish a mouse model of KD-like vasculitis, while the control group mice were injected with an equal volume of normal saline. The general conditions of the mice were observed on the 3rd, 7th, and 14th day after injection. Changes in coronary artery tissue pathology were observed using hematoxylin-eosin staining. The level of CHI3L1 in mouse serum was measured by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to detect the expression and localization of CHI3L1, von Willebrand factor (vWF), and α-smooth muscle actin (α-SMA) in coronary artery tissue. Western blot analysis was used to detect the expression of CHI3L1, vWF, vascular endothelial cadherin (VE cadherin), Caspase-3, B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), nuclear factor κB (NF-κB), and phosphorylated NF-κB (p-NF-κB) in coronary artery tissue.

RESULTS

The serum level of CHI3L1 in the model group was significantly higher than that in the control group (P<0.05). Compared to the control group, the expression of CHI3L1 in the coronary artery tissue was higher, while the expression of vWF was lower in the model group. The relative expression levels of CHI3L1, Bax, Caspase-3, NF-κB, and p-NF-κB were significantly higher in the model group than in the control group (P<0.05). The relative expression levels of vWF, VE cadherin, and Bcl-2 were lower in the model group than in the control group (P<0.05).

CONCLUSIONS

In the LCWE-induced mouse model of KD-like vasculitis, the expression levels of CHI3L1 in serum and coronary arteries increase, and it may play a role in coronary artery lesions through endothelial cell apoptosis mediated by inflammatory reactions.

[Diagnostic value of novel hepatic fibrosis markers in assessing cirrhosis in patients with chronic hepatitis C]

Objective: To investigate the efficacy of chitinase-3-like protein 1 (CHI3L1) and Golgi protein 73 (GP73) in the diagnosis of cirrhosis and the dynamic changes of CHI3L1 and GP73 after HCV clearance in patients with chronic hepatitis C (CHC) treated with direct-acting antiviral drugs (DAAs). The comparison of continuous variables of normal distribution were statistically analyzed by ANOVA and t-test. The comparison of continuous variables of non-normal distribution were statistically analyzed by rank sum test. The categorical variables were statistically analyzed by Fisher's exact test and χ(2) test. Correlation analysis was performed using Spearman correlation analysis. Methods: Data of 105 patients with CHC diagnosed from January 2017 to December 2019 were collected. The receiver operating characteristic curve (ROC curve) was plotted to study the efficacy of serum CHI3L1 and GP73 for the diagnosis of cirrhosis. Friedman test was used to compare CHI3L1 and GP73 change characteristics. Results: The areas under the ROC curve for CHI3L1 and GP73 in the diagnosis of cirrhosis at baseline were 0.939 and 0.839, respectively. Serum levels of CHI3L1 and GP73 in the DAAs group decreased significantly at the end of treatment compared with baseline [123.79 (60.25, 178.80) ng/ml vs. 118.20 (47.68, 151.36) ng/ml, P = 0.001; 105.73 (85.05, 130.69) ng/ml vs. 95.52 (69.52, 118.97) ng/ml, P = 0.001]. Serum CHI3L1 and GP73 in the pegylated interferon combined with ribavirin (PR) group were significantly lower at the end of 24 weeks of treatment than the baseline [89.15 (39.15, 149.74) ng/ml vs. 69.98 (20.52, 71.96) ng/ml, P < 0.05; 85.07 (60.07, 121) ng/ml vs. 54.17 (29.17, 78.65) ng/ml, P < 0.05]. Conclusion: CHI3L1 and GP73 are sensitive serological markers that can be used to monitor the fibrosis prognosis in CHC patients during treatment and after obtaining a sustained virological response. Serum CHI3L1 and GP73 levels in the DAAs group decreased earlier than those in the PR group, and the serum CHI3L1 levels in the untreated group increased compared with the baseline at about two years of follow-up.

Effects of Peroral Omega-3 Fatty Acid Supplementation on Cerebrospinal Fluid Biomarkers in Patients with Alzheimer's Disease: A Randomized Controlled Trial-The OmegAD Study

BACKGROUND

Studies have suggested a connection between a decrease in the levels of polyunsaturated fatty acids (PUFAs) and Alzheimer's disease (AD). We aimed to assess the effect of supplementation with omega-3 fatty acids (n-3 FAs) on biomarkers analyzed in the cerebrospinal fluid (CSF) of patients diagnosed with AD.

OBJECTIVE

To investigate the effects of daily supplementation with 2.3 g of PUFAs in AD patients on the biomarkers in CSF described below. We also explored the possible correlation between these biomarkers and the performance in the cognitive test Mini-Mental State Examination (MMSE).

METHODS

Thirty-three patients diagnosed with AD were randomized to either treatment with a daily intake of 2.3 g of n-3 FAs (n  =  18) or placebo (n  =  15). CSF samples were collected at baseline and after six months of treatment, and the following biomarkers were analyzed: Aβ 38, Aβ 40, Aβ 42, t-tau, p-tau, neurofilament light (NfL), chitinase-3-like protein 1 (YKL-40), acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), soluble IL-1 receptor type II (sIL-1RII), and IL-6.

RESULTS

There were no significant differences between the groups concerning the level of the different biomarkers in the CSF at baseline. Within the treatment group, there was a small but significant increase in both YKL-40 (p = 0.04) and NfL (p = 0.03), while the other CSF biomarkers remained stable.

CONCLUSION

Supplementation with n-3 FAs had a statistically significant effect on NfL and YKL-40, resulting in an increase of both biomarkers, indicating a possible increase of inflammatory response and axonal damage. This increase in biomarkers did not correlate with MMSE score.

Effects of chitinase-3-like protein 1 on brain death-induced hepatocyte apoptosis via PAR2-JNK-caspase-3

Hepatocyte apoptosis is a crucial factor affecting liver quality in brain-dead donors. The identification of key molecular proteins involved in brain-death (BD)-induced hepatocyte apoptosis may help determine an effective method for improving the quality of livers from brain-dead donors. In this study, we used in vivo and in vitro models to investigate the role of chitinase-3-like protein 1 (CHI3L1) in promoting liver cell apoptosis after BD. Chitin was used to inhibit CHI3L1 in a rat model of BD. Macrophage polarization of THP-1 cells and hypoxia/reoxygenation (H/R) of LO-2 cells were used to mimic BD-induced cell stress in liver. We found that CHI3L1 played a vital role in promoting liver cell apoptosis. Six hours after BD, CHI3L1 expression was significantly upregulated in liver macrophages and was associated with BD-induced M1 polarization of these cells. In liver cells cultured under H/R conditions, recombinant CHI3L1 activated the protease-activated receptor 2 (PAR2)/c-June N-terminal kinase (JNK) apoptotic pathway and aggravated apoptosis. Compared with the control group, chitin particles inhibited the expression of CHI3L1 in the liver of brain dead rats, thereby reducing activation of the hepatocyte surface receptor, PAR2, and its downstream JNK/caspase-3 signaling pathway, ultimately reducing hepatocyte apoptosis. In conclusion, our results indicate that CHI3L1 relies on a PAR2/JNK-mediated mechanism to promote BD-induced hepatocyte apoptosis.

Efficacy of chitinase-3-like protein 1 as an in vivo bone formation predictable marker of maxillary/mandibular bone marrow stromal cells

Introduction

Maxillary/mandibular bone marrow stromal cells (MBMSCs) are a useful cell source for bone regeneration in the oral and maxillofacial region. To further ensure the clinical application of MBMSCs in bone regenerative therapy, it is important to determine the bone formation capacity of MBMSCs before transplantation. The aim of this study is to identify the molecular marker that determines the in vivo bone formation capacity of MBMSCs.

Methods

The cell growth, cell surface antigens, in vitro and in vivo bone formation capacity of MBMSCs were examined. The amount of chitinase-3-like protein 1 (CHI3L1) secreted into the conditioned medium was quantified. The effects of CHI3L1 on the cell growth and osteogenic differentiation potential of MBMSCs and on the cell growth and migration of vascular endothelial cells and fibroblasts were examined.

Results

The cell growth, and in vitro and in vivo bone formation capacity of the cells treated with different conditions were observed. MBMSCs that secreted a large amount of CHI3L1 into the conditioned medium tended to have low in vivo bone formation capacity, whereas MBMSCs that secreted a small amount of CHI3L1 had greater in vivo bone formation capacity. CHI3L1 promoted the migration of vascular endothelial cells, and the cell growth and migration of fibroblasts.

Conclusion

Our study indicates that the in vitro osteogenic differentiation capacity of MBMSCs and the in vivo bone formation capacities of MBMSCs were not necessarily correlated. The transplantation of high CHI3L1 secretory MBMSCs may suppress bone formation by inducing fibrosis at the site. These results suggest that the CHI3L1 secretion levels from MBMSCs may be used as a predictable marker of bone formation capacity in vivo.

•

In vitro and in vivo bone formation capacities of MBMSCs were not correlated.

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MBMSCs with high CHI3L1 secretion tended to have low in vivo bone formation.

•

MBMSCs with low CHI3L1 secretion tended to have high in vivo bone formation.

•

CHI3L1 can be in vivo bone formation capacity predictable marker of MBMSCs.

Effect of chitinase-3-like protein 1 on glucose metabolism: In vitro skeletal muscle and human genetic association study

We investigated the effect of chitinase-3-like protein 1 (CHI3L1) on glucose metabolism and its underlying mechanisms in skeletal muscle cells, and evaluated whether the observed effects are relevant in humans. CHI3L1 was associated with increased glucose uptake in skeletal muscles in an AMP-activated protein kinase (AMPK)-dependent manner, and with increased intracellular calcium levels via PAR2. The improvement in glucose metabolism observed in an intraperitoneal glucose tolerance test on male C57BL/6J mice supported this association. Inhibition of the CaMKK was associated with suppression of CHI3L1-mediated glucose uptake. Additionally, CHI3L1 was found to influence glucose uptake through the PI3K/AKT pathway. Results suggested that CHI3L1 stimulated the phosphorylation of AS160 and p38 MAPK downstream of AMPK and AKT, and the resultant GLUT4 translocation. In primary myoblast cells, stimulation of AMPK and AKT was observed in response to CHI3L1, underscoring the biological relevance of CHI3L1. CHI3L1 levels were elevated in cells under conditions that mimic exercise in vitro and in exercised mice in vivo, indicating that CHI3L1 is secreted during muscle contraction. Finally, similar associations between CHI3L1 and metabolic parameters were observed in humans alongside genotype associations between CHI3L1 and diabetes at the population level. CHI3L1 may be a potential therapeutic target for the treatment of diabetes.

Serum chitinase-3-like protein 1 is a biomarker of liver fibrosis in patients with chronic hepatitis B in China

BACKGROUND

Serum chitinase-3-like protein 1 (CHI3L1) is a potential biomarker for fibrosis assessment. We aimed to evaluate serum CHI3L1 as a noninvasive diagnostic marker for chronic hepatitis B virus-related fibrosis.

METHODS

Serum CHI3L1 levels were measured by ELISA in 134 chronic hepatitis B (CHB) patients. Significant fibrosis was defined as a liver stiffness > 9.7 kPa. The performance of CHI3L1 was assessed and compared to that of other noninvasive tests by receiver operating characteristic (ROC) analysis.

RESULTS

Serum CHI3L1 levels were significantly higher in CHB patients with significant hepatic fibrosis (≥ F2, 81.9 ng/mL) than in those without significant hepatic fibrosis (< F2, 56.5 ng/mL) (P < 0.001). In CHB patients, the specificity and sensitivity of CHI3L1 for predicting significant fibrosis were 75.6% and 59.1%, respectively, with a cut-off of 76.0 ng/mL and an area under the ROC curve of 0.728 (95% CI: 0.637-0.820).

CONCLUSIONS

Serum CHI3L1 levels could be an effective new serological biomarker for the diagnosis of liver. Moreover, CHI3L1 is feasible in monitoring disease progression.

Biomarker profiling beyond amyloid and tau: cerebrospinal fluid markers, hippocampal atrophy, and memory change in cognitively unimpaired older adults

Brain changes occurring in aging can be indexed by biomarkers. We used cluster analysis to identify subgroups of cognitively unimpaired individuals (n = 99, 64-93 years) with different profiles of the cerebrospinal fluid biomarkers beta amyloid 1-42 (Aβ42), phosphorylated tau (P-tau), total tau, chitinase-3-like protein 1 (YKL-40), fatty acid binding protein 3 (FABP3), and neurofilament light (NFL). Hippocampal volume and memory were assessed across multiple follow-up examinations covering up to 6.8 years. Clustering revealed one group (39%) with more pathological concentrations of all biomarkers, which could further be divided into one group (20%) characterized by tauopathy and high FABP3 and one (19%) by brain β-amyloidosis, high NFL, and slightly higher YKL-40. The clustering approach clearly outperformed classification based on Aβ42 and P-tau alone in prediction of memory decline, with the individuals with most tauopathy and FABP3 showing more memory decline, but not more hippocampal volume change. The results demonstrate that older adults can be classified based on biomarkers beyond amyloid and tau, with improved prediction of memory decline.

MicroRNA-24 protects retina from degeneration in rats by down-regulating chitinase-3-like protein 1

MicroRNAs (miRNAs) have been shown to play critical roles in the pathogenesis and progression of degenerative retinal diseases like age-related macular degeneration (AMD). In this study, we first demonstrated that miR-24 plays an important role in maintaining retinal structure and visual function of rats by targeting chitinase-3-like protein 1 (CHI3L1). In the retinal pigment epithelial (RPE) cells of Royal College of Surgeons (RCS) rats, an animal model of genetic retinal degeneration (RD), miR-24 was found lower and CHI3L1 level was higher in comparison with those in Sprague-Dawley (SD) rats. Other changes in the eyes of RCS rats include activated AKT/mTOR and ERK pathways and abnormal autophagy in the RPE cells. Such roles of miR-24 and CHI3L1 were further confirmed in RCS rats by subretinal injection of agomiR-24, which decreased CHI3L1 level and preserved retinal structure and function. Upstream, NF-κB was identified as the regulator of miR-24 in the RPE cells of these rats. On the other hand, in SD rats, intraocular treatment of antagomiR-24 induced pathological changes similar to those in RCS rats. The results revealed the protective roles for miR-24 to RPE cells and a mechanism for RD in RCS rats was proposed: extracellular stress stimuli first activate the NF-κB signaling pathway, which lowers miR-24 expression so that CHI3L1 increased. CHI3L1 sequentially results in aberrant autophagy and RPE dysfunction by activating AKT/mTOR and ERK pathways. Taken together, although the possibility, that the therapeutic effects in RCS rats are caused by other transcriptional changes regulated by miR-24, cannot be excluded, these findings indicate that miR-24 protects rat retina by targeting CHI3L1. Thus, miR-24 and CHI3L1 might be the targets for developing more effective therapy for degenerative retinal diseases like AMD.

Chitinase-3-like Protein 1 (YKL-40) Is Expressed in Lesional Skin in Hidradenitis Suppurativa

BACKGROUND/AIM

Hidradenitis suppurativa (HS) is a chronic disease. Recently, we suggested, chitinase-3-like protein 1 (YKL-40) as a new biomarker for HS since its serum levels were found to be elevated in patients. The objective of this study was to examine YKL-40 tissue expression in HS.

MATERIALS AND METHODS

The study was conducted on 7 patients with HS. The biopsies were obtained from lesional and non-lesional skin. The tissue expression of YKL-40 was assessed using an immunohistochemical method.

RESULTS

Inflammatory infiltrates of various grades were visible in all samples of lesional skin. The inflammatory cells within those infiltrates showed a strong cytoplasmic expression of YKL-40. In non-lesional HS skin the pattern of YKL-40 expression was similar to that observed in healthy skin.

CONCLUSION

Inflammatory infiltrates in HS skin lesions may be responsible for the elevated YKL-40 serum level. YKL-40 can be considered one of the most valuable biomarkers of HS.

Glial activation and inflammation along the Alzheimer's disease continuum

Background

Neuronal and glial cell interaction is essential for synaptic homeostasis and may be affected in Alzheimer’s disease (AD). We measured cerebrospinal fluid (CSF) neuronal and glia markers along the AD continuum, to reveal putative protective or harmful stage-dependent patterns of activation.

Methods

We included healthy controls (n = 36) and Aβ-positive (Aβ+) cases (as defined by pathological CSF amyloid beta 1-42 (Aβ42)) with either subjective cognitive decline (SCD, n = 19), mild cognitive impairment (MCI, n = 39), or AD dementia (n = 27). The following CSF markers were measured: a microglial activation marker—soluble triggering receptor expressed on myeloid cells 2 (sTREM2), a marker of microglial inflammatory reaction—monocyte chemoattractant protein-1 (MCP-1), two astroglial activation markers—chitinase-3-like protein 1 (YKL-40) and clusterin, a neuron-microglia communication marker—fractalkine, and the CSF AD biomarkers (Aβ42, phosphorylated tau (P-tau), total tau (T-tau)). Using ANOVA with planned comparisons, or Kruskal-Wallis tests with Dunn’s pairwise comparisons, CSF levels were compared between clinical groups and between stages of biomarker severity using CSF biomarkers for classification based on amyloid pathology (A), tau pathology (T), and neurodegeneration (N) giving rise to the A/T/N score.

Results

Compared to healthy controls, sTREM2 was increased in SCD (p < .01), MCI (p < .05), and AD dementia cases (p < .001) and increased in AD dementia compared to MCI cases (p < .05). MCP-1 was increased in MCI (p < .05) and AD dementia compared to both healthy controls (p < .001) and SCD cases (p < .01). YKL-40 was increased in dementia compared to healthy controls (p < .01) and MCI (p < .05). All of the CSF activation markers were increased in subjects with pathological CSF T-tau (A+T−N+ and A+T+N+), compared to subjects without neurodegeneration (A−T−N− and A+T−N−).

Discussion

Microglial activation as indicated by increased sTREM2 is present already at the preclinical SCD stage; increased MCP-1 and astroglial activation markers (YKL-40 and clusterin) were noted only at the MCI and AD dementia stages, respectively, and in Aβ+ cases (A+) with pathological T-tau (N+). Possible different effects of early and later glial activation need to be explored.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1399-2) contains supplementary material, which is available to authorized users.

Chitinase-3-like protein 1 may be a potential biomarker in patients with drug-resistant epilepsy

The mechanisms of the pathogenesis of epilepsy remain unclear. Recent research shows that the inflammatory process occurring in the brain may be a common and critical mechanism of seizures. Chitinase-3-like protein 1 (CHI3L1 or YKL-40) is a newly discovered inflammatory factor. We aimed to evaluate the role of YKL-40 as a biomarker for epilepsy. 124 subjects were classified as control group (n = 23), new-diagnosis epilepsy group (NDE, n = 34), drug responsive epilepsy group (DPE, n = 37), and drug-resistant epilepsy group (DRE, n = 30) YKL-40 was measured by ELISA in serum and cerebrospinal fluid (CSF). The concentrations of serum and CSF YKL-40 and its diagnostic accuracy for epilepsy were analysed. Patients with DRE had higher concentrations of YKL-40 in serum and CSF, while patients with NDE and DPE had increased YKL-40 levels in CSF but not serum in comparison with control. Moreover, serum and CSF YKL-40 provide high diagnostic accuracy for DRE. YKL-40 may play a possible pathogenic role in epilepsy. YKL-40 may represent a potential biomarker of brain inflammation in patients with DRE.

Association of the Polymorphisms and Plasma Level of CHI3L1 with Alzheimer's Disease in the Chinese Han Population: A Case-Control Study

OBJECTIVE

To investigate whether the polymorphisms and plasma level of chitinase-3-like protein 1 (CHI3L1) are associated with Alzheimer's disease (AD) in the Chinese Han population.

METHODS

A total of 166 patients who were initially diagnosed with AD were enrolled as the case group, and 184 healthy subjects were recruited as the healthy controls. TaqMan® SNP genotyping assays were applied for the genotyping of rs4950928, rs10399931 and rs6691378. The plasma level of CHI3L1 was determined by enzyme-linked immunosorbent assay.

RESULTS

The CG+GG genotype of rs4950928 C>G is a protective factor for AD and could effectively reduce the severity of AD. Patients with the CT+TT genotype of rs10399931 C>T had a significantly increased risk of AD, and it apparently aggravated the severity of AD. Moreover, the plasma CHI3L1 level in AD patients was significantly higher than that in healthy controls, which was increased with the severity of AD. A Kaplan-Meier survival curve showed that significant differences in 5-year survival rates were found in AD patients in different genotypes of CHI3L1 rs4950928 C>G and rs10399931 C>T. The AD patients and healthy controls who carried the CG+GG genotype of rs4950928 C>G had lower plasma CHI3L1 levels than CC genotype carriers. However, the CT+TT genotype of rs10399931 in the AD patients had an elevated plasma level of CHI3L1 as compared with the CC genotype. Binary logistic regression analysis showed that the plasma level of CHI3L1, the CC genotype of rs4950928 C>G and the CT+TT genotype of rs10399931 C>T were risk factors for AD.

CONCLUSION

Polymorphisms of the CHI3L1 gene (rs4950928 C>G and rs10399931 C>T) are associated with the risk and prognosis of AD and can affect the expression of CHI3L1 in plasma.

Obesity modulates the association between sleep apnea treatment and CHI3L1 levels but not CHIT1 activity in moderate to severe OSA: an observational study

Purpose

The inflammatory markers chitinase-3-like protein 1 (CHI3L1) and chitotriosidase (CHIT1) have both been associated with cardiovascular complications. The aim of this preliminary observational study was to assess the roles and interaction of obstructive sleep apnea (OSA) severity and body mass index (BMI) with plasma CHI3L1 levels and CHIT1 activity in patients with moderate to severe OSA. The second aim was to assess the roles and interaction of positive airway pressure (PAP) treatment and BMI on the expression of the same proteins.

Methods

The study included 97 OSA patients with an apnea–hypopnea index (AHI) ≥ 15 and full usage of PAP treatment after 4 months. Plasma CHI3L1 levels and CHIT1 activity were measured before and after treatment.

Results

Multiple linear regression analysis demonstrated an independent association of BMI on CHI3L1 levels (p < 0.05) but not on CHIT1 activity. The OSA severity markers (AHI and oxygen desaturation index) did not independently or in interaction with BMI levels associate with CHI3L1 levels or with CHIT1 activity (p > 0.05). A two-way repeated measures ANOVA revealed a significant interaction between PAP treatment effect (before vs. after) and BMI groups (< 35 kg/m² vs. ≥ 35 kg/m²) on CHI3L1 levels (p = 0.03) but not on CHIT1 activity (p = 0.98).

Conclusions

Obesity independently associated with CHI3L1 levels. Association between OSA severity and CHI3L1 levels or CHIT1 activity (independent of or dependent on obesity level) could not be confirmed. However, decrease was observed in CHI3L1 levels after PAP treatment in severely obese OSA patients but not in those less obese.

Electronic supplementary material

The online version of this article (10.1007/s11325-018-1731-6) contains supplementary material, which is available to authorized users.

Cerebrospinal fluid phosphorylated tau, visinin-like protein-1, and chitinase-3-like protein 1 in mild cognitive impairment and Alzheimer's disease

Background

Visinin-like protein-1 (VILIP-1) and chitinase-3-like protein 1 (CHI3L1 or YKL-40) in cerebrospinal fluid (CSF) are newly discovered markers indicating neuronal damage and microglial activation, respectively. Phosphorylated tau (p-tau) reflects the neuropathology of Alzheimer's disease (AD) and is useful as diagnostic markers for AD. However, it is unknown whether these biomarkers have similar or complementary information in AD.

Methods

We stratified 121 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database into cognitively normal (CN), stable mild cognitive impairment (sMCI), progressive MCI (pMCI), and dementia due to AD. Analysis of covariance (ANOVA) and chi-square analyses, Spearman correlation, and logistic regression models were performed to test the demographic, associations between biomarkers, and diagnostic accuracies, respectively. Linear mixed-effects models were used to evaluate the effects of CSF amyloid-β (Aβ) on above biomarkers within diagnostic groups, the combination of diagnostic group and Aβ status as predictor, and CSF biomarkers as predictors of AD features, including cognition measured by Mini-Mental State Examination (MMSE) and brain structure and white matter hyperintensity (WMH) measured by magnetic resonance imaging (MRI).

Results

P-tau, VILIP-1, and YKL-40 were all predictors of AD diagnosis, but combinations of biomarkers did not improve the diagnostic accuracy (AUC 0.924 for p-tau, VILIP-1, and YKL-40) compared to p-tau (AUC 0.922). P-tau and VILIP-1 were highly correlated (r = 0.639, p < 0.001) and strongly associated with Aβ pathology across clinical stages of AD, while YKL-40 was correlated with Aβ pathology in CN and AD groups. VILIP-1 was associated with acceleration of cognitive decline, hippocampal atrophy, and expansion of ventricles in longitudinal analyses. YKL-40 was associated with hippocampal atrophy at baseline and follow-up, while p-tau was only associated with worsening WMH at baseline.

Conclusions

CSF levels of p-tau, VILIP-1, and YKL-40 may have utility for discriminating between cognitively normal subjects and patients with AD. Increased levels of both VILIP-1 and YKL-40 may be associated with disease degeneration. These CSF biomarkers should be considered for future assessment in the characterization of the natural history of AD.

A Novel Biomarker in Diabetic Macular Edema with Serous Retinal Detachment: Serum Chitinase-3-Like Protein 1

PURPOSE

To determine whether serum chitinase-3-like protein 1 (CHI3L1) and interleukin-6 (IL-6) levels correlate with serous retinal detachment (SRD) in diabetic macular edema (DME) using spectral-domain optical coherence tomography (SD-OCT).

METHODS

In this cross-sectional case-control study, 394 patients (treatment-naive DME patients, n = 218; diabetic patients without DME, n = 96; nondiabetic controls, n = 80) were included in the study. Eyes were classified according to SD-OCT features of DME: SRD, cystoid macular edema (CMO), and diffuse retinal thickness (DRT). Serum concentrations of CHI3L1 and IL-6 were analyzed using enzyme-linked immunosorbent assay.

RESULTS

Serum CHI3L1 and IL-6 levels were significantly higher in DME with SRD compared to patients with CMO and DRT (p < 0.001 for all groups). Multivariate regression analysis showed that CHI3L1 and IL-6 had a stronger influence on the presence of SRD in DME (r = 1.162, p = 0.026, and r = 1.242, p = 0.016, respectively). Serum concentration of CHI3L1 was significantly correlated with that of IL-6 (r = 0.386, p = 0.0015).

CONCLUSIONS

Our data suggest that serum concentrations of CHI3L1 and IL-6 are involved in the process of SRD in DME. CHI3L1 can be investigated further as a new diagnostic biomarker for DME with SRD.

[Diagnostic value of serum chitinase-3-like protein 1 in chronic liver disease of significant fibrosis and cirrhosis]

Objective: To study the correlation between the level of serum Chitinase-3-like protein 1 (CHI3L1) and the significant liver fibrosis and liver cirrhosis in patients with chronic liver disease, and to evaluate its diagnostic value. Methods: 165 patients with chronic liver disease were selected, liver histopathological examination was performed to detect serum CHI3L1 concentration. Four indexes of hepatic fibrosis (type III procollagen, collagen IV, laminin, hyaluronic acid), aspartate aminotransferase/platelet ratio index (APRI) and FIB-4 (fibrosis- 4) scores were based on the pathological findings of liver biopsy and compared the advantages and disadvantages of serum CHI3L1 with other methods for the diagnosis of hepatic fibrosis and liver cirrhosis. A multivariate regression analysis model was created, and receiver operating characteristic curve was analyzed. Results: The level of serum CHI3L1 increased with increase of fibrosis stage and was highest in liver cirrhosis stage. In the period of S0 to 1, the levels of S2 to 3 and S4 were 62.82 (41.40 ~ 87.20), 70.94 (48.47 to 122.60) and 141.06 (78.18 ~ 197.40), and there were statistically significant differences between the groups (P < 0.001). The area under the curve for the diagnosis of significant liver fibrosis was 0.68 (0.60 to 0.77), and 0.74 (0.65 to 0.83) for cirrhosis in CHI3L1. Multivariate regression analysis showed that CHI3L1 was an independent predictor of significant fibrosis and cirrhosis. The combined diagnostic model based on CHI3L1, collagen IV and FIB-4 scores further improved the diagnostic value. The area under the curve for the diagnosis of significant fibrosis and cirrhosis was 0.79 (0.72 to 0.86) and 0.80 (0.73 to 0.87), respectively. Conclusion: CHI3L1 has a good diagnostic value in patients with chronic liver disease with significant fibrosis and liver cirrhosis. The diagnostic model in combination with other markers like Collagen IV and FIB-4 scores could further improve the diagnostic value and is worthy of further study.

YKL-40/chitinase-3-like protein 1 is associated with poor prognosis and promotes cell growth and migration of cholangiocarcinoma

YKL-40, a chitinase-like glycoprotein, is expressed at a high level in cancer patients. Its exact function is unknown and is the subject of current investigation. Here, we report the correlation of plasma YKL-40 levels with clinicopathological features of cholangiocarcinoma (CCA), a lethal bile duct cancer, particularly prevalent in Northeastern Thailand. Statistical analysis of plasma YKL-40 concentrations in 57 CCA patients and 41 normal healthy subjects gave a median value of 169.5 ng/mL for CCA patients compared with 46.9 ng/mL for the control subjects (P < 0.0001). There was no significant association of plasma YKL-40 levels with patient age, tumor grade, or histology type. However, Kaplan-Meier analysis suggested that the elevated plasma YKL-40 level was particularly associated with short survival in CCA patients (P = 0.038). Immunohistochemical examination of 34 CCA tissues revealed low expression of YKL-40 in CCA cells, but high expression in adjacent intratumoral stroma, liver, and connective tissues. Univariate analysis showed significant association of the intratumoral YKL-40 expression in CCA tissues with the non-papillary type CCA. Addition of rYKL-40 in the culture medium and transient expression of YKL-40 in CCA cell lines were shown to promote the growth and migration of the tumor cells, and that YKL-40 interacted with a cell-surface receptor involved in the Akt/Erk-mediated pathway. In conclusion, our results support the proposal of YKL-40 as a new candidate prognostic biomarker for cancer diseases.