Correlation between serum YKL-40 levels and albuminuria in type 2 diabetes

Increased levels of YKL-40 in patients with diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Diabetes mellitus (DM) could be classified as type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), gestational diabetes mellitus (GDM) and others according to etiology and pathology. Diabetic nephropathy (DN) is one of the most serious complications of DM. YKL-40 is a marker of inflammation and some studies have indicated that DM was related with inflammation. The objective of our study is to perform a systematic review and meta-analysis to confirm the relationship between YKL-40 and DM as well as DN.

METHODS

Pubmed, Embase, CNKI and Chinese wanfang databases were searched for eligible studies by two independent authors. Studies were included in this meta-analysis if they fulfilled the following inclusion criteria: (1) a study involving the role of YKL-40 in DM (or DN) designed as a case-control study or cohort study; (2) the data of serum YKL-40 levels were available; (3) studies were published in English or Chinese. Finally, twenty-five studies were included in this meta-analysis.

RESULTS

Compared with healthy controls, DM patients had significantly higher levels of YKL-40 (DM: SMD = 1.62, 95% CI 1.08 to 2.25, P = 0.000; GDM: SMD = 2.85, 95% CI 1.01 to 4.70, P = 0.002). Additionally, DM patients with different degree of albuminuria had significantly higher levels of YKL-40 compared with healthy controls (normoalbuminuria: SMD = 1.58, 95% CI 0.59 to 2.56, P = 0.002; microalbuminuria: SMD = 2.57, 95% CI 0.92 to 4.22, P = 0.002; macroalbuminuria: SMD = 2.69, 95% CI 1.40 to 3.98, P = 0.000) and serum YKL-40 levels increased with increasing severity of albuminuria among DM patients (microalbuminuria vs normoalbuminuria: SMD = 1.49, 95% CI 0.28 to 2.71, P = 0.016; macroalbuminuria vs microalbuminuria: SMD = 0.93, 95% CI 0.34 to 1.52, P = 0.002).

CONCLUSIONS

Our current meta-analysis demonstrates that serum level of YKL-40 is increased in DM and positively associated with the severe degree of albuminuria. Therefore, we suggest that YKL-40 could be considered to be detected, along with other inflammatory markers, if DM, especially DN, is suspected.

Diagnostic Performance of Biomarkers Urinary KIM-1 and YKL-40 for Early Diabetic Nephropathy, in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

There is a lack of prediction markers for early diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (T2DM). The aim of this systematic review and meta-analysis was to evaluate the performance of two promising biomarkers, urinary kidney injury molecule 1 (uKIM-1) and Chitinase-3-like protein 1 (YKL-40) in the diagnosis of early diabetic nephropathy in type 2 diabetic patients. A comprehensive search was performed on PubMed by two reviewers until May 2020. For each study, a 2 × 2 contingency table was formulated. Sensitivity, specificity, and other estimates of accuracy were calculated using the bivariate random effects model. The hierarchical summary receiver operating characteristic curve hsROC) was used to pool data and evaluate the area under curve (AUC). The sources of heterogeneity were explored by sensitivity analysis. Publication bias was assessed using Deek’s test. The meta-analysis enrolled 14 studies involving 598 healthy individuals, 765 T2DM patients with normoalbuminuria, 549 T2DM patients with microalbuminuria, and 551 T2DM patients with macroalbuminuria, in total for both biomarkers. The AUC of uKIM-1 and YKL-40 for T2DM patients with normoalbuminuria, was 0.85 (95%CI; 0.82–0.88) and 0.91 (95%CI; 0.88–0.93), respectively. The results of this meta-analysis suggest that both uKIM-1 and YKL-40 can be considered as valuable biomarkers for the early detection of DN in T2DM patients with the latter showing slightly better performance than the former.

Common Pathological Mechanisms and Risk Factors for Alzheimer's Disease and Type-2 Diabetes: Focus on Inflammation

BACKGROUND

Diabetes is considered as a risk factor for Alzheimer's Disease, but it is yet unclear whether this pathological link is reciprocal. Although Alzheimer's disease and diabetes appear as entirely different pathological entities affecting the Central Nervous System and a peripheral organ (pancreas), respectively, they share a common pathological core. Recent evidence suggests that in the pancreas in the case of diabetes, as in the brain for Alzheimer's Disease, the initial pathological event may be the accumulation of toxic proteins yielding amyloidosis. Moreover, in both pathologies, amyloidosis is likely responsible for local inflammation, which acts as a driving force for cell death and tissue degeneration. These pathological events are all inter-connected and establish a vicious cycle resulting in the progressive character of both pathologies.

OBJECTIVE

To address the literature supporting the hypothesis of a common pathological core for both diseases.

DISCUSSION

We will focus on the analogies and differences between the disease-related inflammatory changes in a peripheral organ, such as the pancreas, versus those observed in the brain. Recent evidence suggesting an impact of peripheral inflammation on neuroinflammation in Alzheimer's disease will be presented.

CONCLUSION

We propose that it is now necessary to consider whether neuroinflammation in Alzheimer's disease affects inflammation in the pancreas related to diabetes.

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.

YKL-40: A biomarker for early nephropathy in type 2 diabetic patients and its association with inflammatory cytokines

Diabetic Nephropathy (DN) is an important cause of morbidity and death amongst diabetes. Persistent micro and macroalbuminuria are well known predictors of DN leading to progressive end-stage renal disease. However, albuminuria has several limitations. Increasing evidences show that YKL-40 is highly expressed in variety of inflammatory diseases and also recognized as a non-invasive prognostic biomarker for inflammation. In the present study, we measured plasma YKL-40 levels in different stages of albuminuria and assessed its diagnostic accuracy as a biomarker for DN and correlated with different families of circulatory cytokines. A total of 306 subjects were recruited and divided into three groups [Group-I, control (n = 83), Group-II, Normoalbuminuria (n = 81), Group-III, DN (n = 142)]. Group-III is further subdivided into: Group-IIIa, microalbuminuria (n = 73), Group-IIIb, macroalbuminuria (n = 69). The median levels of YKL-40 (p = 0.001) showed a marked stepwise increase from normo to macroalbuminuria and positively correlated with eGFR. The AUC_ROC for YKL-40 was found to be high [0.95; (95% CI: 0.88-1.0)], when compared to other acute phase markers. Plasma YKL-40 showed a positive correlation with LIGHT/TNFSF14, sIL-6Ra, gp130/sIL-6Rβ, IFN-β, IL-8, TNFSF14, sCD-30 and eGFR meanwhile a negative correlation with TWEAK/TNFSF12, IL-7 like cytokine and IFN-λ2. Plasma YKL-40 could be a potential biomarker for early diagnosis of incipient DN among South Indian population.

A Heparin Binding Motif Rich in Arginine and Lysine is the Functional Domain of YKL-40

The heparin-binding glycoprotein YKL-40 (CHI3L1) is intimately associated with microvascularization in multiple human diseases including cancer and inflammation. However, the heparin-binding domain(s) pertinent to the angiogenic activity have yet been identified. YKL-40 harbors a consensus heparin-binding motif that consists of positively charged arginine (R) and lysine (K) (RRDK; residues 144–147); but they don't bind to heparin. Intriguingly, we identified a separate KR-rich domain (residues 334–345) that does display strong heparin binding affinity. A short synthetic peptide spanning this KR-rich domain successfully competed with YKL-40 and blocked its ability to bind heparin. Three individual point mutations, where alanine (A) substituted for K or R (K337A, K342A, R344A), led to remarkable decreases in heparin-binding ability and angiogenic activity. In addition, a neutralizing anti-YKL-40 antibody that targets these residues and prevents heparin binding impeded angiogenesis in vitro. MDA-MB-231 breast cancer cells engineered to express ectopic K337A, K342A or R344A mutants displayed reduced tumor development and compromised tumor vessel formation in mice relative to control cells expressing wild-type YKL-40. These data reveal that the KR-rich heparin-binding motif is the functional heparin-binding domain of YKL-40. Our findings shed light on novel molecular mechanisms underlying endothelial cell angiogenesis promoted by YKL-40 in a variety of diseases.