Galectin-3 is associated with glomerular filtration rate and outcome in patients with stable decompensated cirrhosis

Unraveling the pathophysiologic role of galectin-3 in chronically injured liver

Galectin-3 (Gal-3) previously referred to as S-type lectins, is a soluble protein that specifically binds to β-galactoside carbohydrates with high specificity. Gal-3 plays a pivotal role in a variety of pathophysiological processes such as cell proliferation, inflammation, differentiation, angiogenesis, transformation and apoptosis, pre-mRNA splicing, metabolic syndromes, fibrosis, and host defense. The role of Gal-3 has also been implicated in liver diseases. Gal-3 is activated upon a hepatotoxic insult to the liver and its level has been shown to be upregulated in fatty liver diseases, inflammation, nonalcoholic steatohepatitis, fibrosis, cholangitis, cirrhosis, and hepatocellular carcinoma (HCC). Gal-3 directly interacts with the NOD-like receptor family, pyrin domain containing 3, and activates the inflammasome in macrophages of the liver. In the chronically injured liver, Gal-3 secreted by injured hepatocytes and immune cells, activates hepatic stellate cells (HSCs) in a paracrine fashion to acquire a myofibroblast like collagen-producing phenotype. Activated HSCs in the fibrotic liver secrete Gal-3 which acts via autocrine signaling to exacerbate extracellular matrix synthesis and fibrogenesis. In the stromal microenvironment, Gal-3 activates cancer cell proliferation, migration, invasiveness, and metastasis. Clinically, increased serum levels and Gal-3 expression were observed in the liver tissue of nonalcoholic steatohepatitis, fibrotic/cirrhotic, and HCC patients. The pathological role of Gal-3 has been experimentally and clinically reported in the progression of chronic liver disease. Therefore, this review discusses the pathological role of Gal-3 in the progression of chronic liver diseases.

Measurement of Plasma Galectin-3 Concentrations in Patients with Catheter Infections: A Post Hoc Retrospective Cohort Study

Catheter-related infections (CRIs) include catheter-associated urinary tract infections (CAUTIs) and central line-associated bloodstream infections (CLABSIs), and they are associated with high morbidity, mortality, and healthcare costs. The diagnosis of a CRI is made difficult by its non-specific symptoms. We aimed to investigate the factors influencing the plasma concentration of galectin-3 in catheter-bearing patients and to explore its potential usefulness as an index for CRIs. Circulating the concentrations of galectin-3, we measured the chemokine (C-C) motif ligand 2, procalcitonin, and C-reactive protein in 110 patients with a central catheter, in 165 patients with a urinary catheter, and in 72 control subjects. Catheter-bearing patients had higher concentrations (p < 0.001) of galectin-3 than the control group [central catheter: 19.1 (14.0−23.4) µg/L; urinary catheter: 17.1 (12.7−25.4) µg/L; control group: 6.1 (5.0−8.7) µg/L]. We identified chronic kidney disease as an independent determinant of galectin-3 concentrations in patients with a central catheter, and serum creatinine, cardiovascular disease, and number of days that the catheter was indwelling were identified as determinants in urinary catheter patients. We found that measuring galectin-3 concentrations in urinary catheter patients with a CRI was more accurate for diagnosis than the other parameters. We conclude that the measurement of galectin-3 concentration may be useful for assessing the inflammatory status of catheter-bearing patients and may contribute to the diagnosis of CRIs in those with a urinary catheter.

Mesenchymal Stem Cells Ameliorate Fibrosis by Enhancing Autophagy via Inhibiting Galectin-3/Akt/mTOR Pathway and by Alleviating the EMT via Inhibiting Galectin-3/Akt/GSK3β/Snail Pathway in NRK-52E Fibrosis

Background and Objectives

Epithelial-Mesenchymal transition (EMT) is one of the origins of myofibroblasts in renal interstitial fibrosis. Mesenchymal stem cells (MSCs) alleviating EMT has been proved, but the concrete mechanism is unclear. To explore the mechanism, serum-free MSCs conditioned medium (SF-MSCs-CM) was used to treat rat renal tubular epithelial cells (NRK-52E) fibrosis induced by transforming growth factor-β1 (TGF-β1) which ameliorated EMT.

Methods and Results

Galectin-3 knockdown (Gal-3 KD) and overexpression (Gal-3 OE) lentiviral vectors were established and transfected into NRK-52E. NRK-52E fibrosis model was induced by TGF-β1 and treated with the SF-MSCs-CM for 24 h after modelling. Fibrosis and autophagy related indexes were detected by western blot and immunocytochemistry. In model group, the expressions of α-smooth muscle actin (α-SMA), fibronectin (FN), Galectin-3, Snail, Kim-1, and the ratios of P-Akt/Akt, P-GSK3β/GSK3β, P-PI3K/PI3K, P-mTOR/mTOR, TIMP1/MMP9, and LC3B-II/I were obviously increased, and E-Cadherin (E-cad) and P62 decreased significantly compared with control group. SF-MSCs-CM showed an opposite trend after treatment compared with model group. Whether in Gal-3 KD or Gal-3 OE NRK-52E cells, SF-MSCs-CM also showed similar trends. However, the effects of anti-fibrosis and enhanced autophagy in Gal-3 KD cells were more obvious than those in Gal-3 OE cells.

Conclusions

SF-MSCs-CM probably alleviated the EMT via inhibiting Galectin-3/Akt/GSK3β/Snail pathway. Meanwhile, Gal-3 KD possibly enhanced autophagy via inhibiting Galectin-3/Akt/mTOR pathway, which synergistically ameliorated renal fibrosis. Targeting galectin-3 may be a potential target for the treatment of renal fibrosis.

Chronic kidney disease predictors in obese adolescents

BACKGROUND

Glomerular hyperfiltration, initiating development of obesity-related glomerulopathy, results in an enlargement of the glomeruli and unsealing of the filtration barrier. It can be followed by adaptive focal segmental glomerulosclerosis and chronic kidney disease (CKD). The aim of the study was to determine the expression pattern of lipid metabolism and selected kidney damage markers in obese adolescents and to identify potential factors which can predict CKD.

METHODS

The study group consisted of 142 adolescents with a BMI z-score > 2. Sixty-two healthy and normal-weight individuals served as controls. The factors associated with the rate of glomerular filtration in obese adolescents were assessed by linear regression methods using univariate and multivariate analyses. The risk of developing CKD was estimated using the Fisher's exact test.

RESULTS

The study group was divided into "elevated," "normal," and "decreased" glomerular filtration rate (GFR) patients. Increased urine galectin-3 (Gal-3) concentration was diagnosed in all patients. "Decreased GFR" subjects expressed increased urine concentration of neutrophil gelatinase-associated lipocalin (NGAL) and daily megalin excretion. Thirty-nine study participants developed CKD. Increased uric acid (UA) concentration was associated with CKD development both in "normal" and "decreased GFR" patients. Additionally, in "normal" GFR patients, increased concentrations of cholesterol (Ch), triglycerides (TG), and NGAL were associated with CKD.

CONCLUSIONS

Increased serum concentrations of Ch, TG, and UA and increased urine concentration of NGAL might predict CKD development in obese adolescents with normal and decreased GFR. A higher resolution version of the Graphical abstract is available as Supplementary information.

Analysis of the Association between Galectin-3 Concentration in Tears and the Severity of Dry Eye Disease: A Case-Control Study

This study aimed to investigate the relationship between the severity of dry eye disease (DED) and galectin-3 concentration (gal-3) and its cleavage (gal-3C) in tear fluid. Twenty-eight DED patients and 14 controls were recruited at Keio University Hospital. The lissamine green conjunctival staining (LG) score, fluorescein corneal staining (FL) score, tear film break-up time (TBUT), Schirmer’s test, and ocular symptoms questionnaire score (dry eye questionnaire score, DEQS) were evaluated. Furthermore, the correlation between these parameters and the concentrations of gal-3 in tears (ng/µg) and the detection rate of gal-3C (%) were analyzed. Gal-3 concentration in tears was positively correlated with the LG score (R = 0.60, p < 0.01), FL score (R = 0.49, p < 0.01), and DEQS (R = 0.45, p < 0.01), and negatively correlated with the TBUT score (R = −0.40, p < 0.01) and Schirmer’s I value (R = −0.36, p < 0.01). The detection rate of gal-3C in tears was significantly associated with the severity of DED, especially with the LG (p < 0.01) and FL (p < 0.01) scores. Therefore, the concentration of gal-3 and the detection rate of gal-3C in tears had a significant relationship with the severity of ocular surface barrier disruption.

New prognostic score based on galectin-3 has similar performance to model for end-stage liver disease and sodium score in patients with stable decompensated cirrhosis

Background

Galectin-3 (gal-3) has been proposed as a marker of established renal impairment, with predictive value in stable decompensated cirrhosis.

Methods

150 stable decompensated patients were assessed in 2 transplant centers. Patients' renal function was assessed using ⁵¹Chromium-EDTA ("true" glomerular filtration rate). We measured basic laboratory variables and gal-3 in serum samples. Factors associated with patients' outcomes were determined.

Results

Our patients were followed up for 12 months (range 1-48, interquartile range [IQR] 6, 95% confidence interval [CI] 10-13.5) and their mean prognostic scores were Child-Turcotte-Pugh (CTP) 7±2 and model for end-stage liver disease and sodium (MELD-Na) 15±6. Median gal-3 levels were 22 ng/mL. In a multivariate analysis of 94 patients (training group), gal-3 (hazard ratio [HR] 1.026, 95% confidence interval [CI] 1.011-1.041; P=0.003) and serum sodium (HR 1.032, 95%CI 1.006-1.062; P=0.05) were the only factors independently associated with patients' outcomes. Kaplan-Meier analysis using the median gal-3 values revealed different times of survival (log-rank P=0.006). We derived a new prognostic score, (0.026) × serum gal-3+ (-0.079) × serum sodium, with very good discriminative accuracy for the outcome (area under the curve [AUC] 0.71, 95%CI 0.63-0.88), similar to that of the MELD-Na score (AUC 0.69, 95%CI 0.67-0.89; P=0.73), while its diagnostic accuracy was validated in the remaining 56 decompensated patients (AUC 0.81, 95%CI 0.65-0.97).

Conclusions

Gal-3 proved to be an accurate and plausible biomarker of renal dysfunction in patients with decompensated cirrhosis. A new prognostic model incorporating gal-3 and sodium was derived, with very good discriminative accuracy for the outcome.