Plasma galectin-3 levels are associated with the risk of incident chronic kidney disease

Serum galectin-3 can help distinguish lupus nephritis from systemic lupus erythematosus and is also correlated with the degree of renal damage in lupus nephritis

Lupus nephritis (LN) constitutes a substantial contributor to morbidity and mortality in systemic lupus erythematosus (SLE). The monitoring of renal function in patients with LN is associated with improved prognostication. The objective of this study was to evaluate the clinical utility of serum galectin-3 (Gal-3) levels in differentiating LN from SLE. Moreover, we sought to ascertain whether serum galectin-3 levels can serve as a marker for the degree of renal impairment in patients with LN. In this cross-sectional study, 42 patients with LN and 12 patients with SLE without nephritis were enrolled. Furthermore, 110 healthy subjects were recruited as controls. Serum Gal-3 levels were quantified using a time-resolved fluoroimmunoassay. Furthermore, Gal-3 levels were analyzed in conjunction with other clinical variables. The results demonstrated that patients with LN exhibited a significantly elevated serum Gal-3 concentration (35.98 ± 20.68 ng/mL) in comparison to healthy controls (10.11 ± 2.75 ng/mL, P < .001) and patients with SLE (14.38 ± 2.26, P < .001). The area under the curve of Gal-3 in distinguishing patients with SLE from patients with LN was 0.9157. When the cutoff value was set to 18.91 ng/mL, the sensitivity was 83.33%, and the specificity was 100%. There was a tendency for serum Gal-3 levels to increase with worsening renal impairment in patients with LN. In conclusion, Gal-3 could be a valuable biomarker for distinguishing LN from SLE, providing a useful clinical reference. Elevated serum Gal-3 levels may be associated with the severity of renal impairment in patients with LN.

Galectin-3: action and clinical utility in chronic kidney disease

Chronic kidney disease is a significant cause of morbidity and mortality worldwide. In recent years, Galectin-3 has been put forward as a potential biomarker of chronic kidney disease progression. This review aims to assess the clinical utility of Galectin-3 in various pathological processes leading up to chronic kidney disease such as diabetes and lupus nephritis. We conducted a systematic search on PubMed from inception to September 2023, using the search term ("Galectin-3" OR "gal-3") AND ("renal" OR "kidney"). Galectin-3 has been shown to be both pro-fibrotic and protective against renal fibrosis through various mechanisms such as apoptotic body clearance and modulation of the Wnt pathway. Studies have found associations between raised Galectin-3, incidence and progression of chronic kidney disease. In lupus nephritis, Galectin-3 may serve as a biomarker for lupus nephritis activity. Although Galectin-3 inhibits cystogenesis, there is no correlation between total kidney volume and Galectin-3 in polycystic kidney disease. The role of Galectin-3 in staging and prognostication of renal cell carcinoma is yet to be determined. Galectin-3 has potential in predicting chronic kidney disease progression, in combination with other biomarkers. However, more trials are required given that present studies demonstrate conflicting results on the relationship between Galectin-3 and clinical outcomes in chronic kidney disease patients of varying aetiologies.

Association of suPAR, ST2, and galectin-3 with eGFR decline and mortality in patients with advanced heart failure with reduced ejection fraction

Patients with heart failure with reduced ejection fraction (HFrEF) are at risk for chronic kidney disease (CKD). Elevated levels of circulating biomarkers soluble urokinase plasminogen activator receptor (suPAR), galectin-3, soluble suppression of tumorigenicity 2 (ST2), and N-terminal prohormone B-type natriuretic peptide (NT-proBNP) are associated with CKD progression and mortality. The predictive value of these biomarkers in a population with HFrEF and kidney disease is relatively unknown. We sought to determine whether these biomarkers were associated with longitudinal trajectory of estimated glomerular filtration rate (eGFR) in HFrEF and assess their association with mortality using a joint model to account for competing risks of ventricular assist device (VAD) implantation and heart transplantation. We included participants from the Registry Evaluation of Vital Information for Ventricular Assist Devices in Ambulatory Life with repeated eGFR measures over 2 years. Of 309 participants, mean age was 59 years, median eGFR 60 ml/min/1.73 m2, 45 participants died, 33 received VAD, and 25 received orthotopic heart transplantation. Higher baseline serum standardized suPAR (β coefficient = -0.36 √(ml/min/1.73 m2), 95% confidence interval (-0.48 to -0.24), p < 0.001), standardized galectin-3 (-0.14 √(ml/min/1.73 m2) (-0.27 to -0.02), p = 0.02), and log NT-proBNP (-0.23 √(ml/min/1.73 m2) (-0.31 to -0.15), p < 0.001) were associated with eGFR decline. ST2 and log NT-proBNP were associated with mortality. Higher baseline suPAR, galectin-3, and NT-proBNP are associated with eGFR decline in patients with HFrEF. Only ST2 and NT-proBNP are associated with greater mortality after controlling for other factors including change in eGFR. These biomarkers may provide prognostic value for kidney disease progression in HFrEF and inform candidacy for advanced heart failure therapies.

Circulating galectin-3 level association with cardiovascular risk factors during peritoneal dialysis

OBJECTIVE

Cardiovascular disease (CVD) represents the primary cause of mortality in patients afflicted with end-stage renal disease and undergoing peritoneal dialysis (PD) treatment. Galectin-3 (Gal-3), a molecule known to exhibit a correlation with CVD mortality garners considerable interest. The objective of this study was to explore the potential association between serum Gal-3 levels and other CVD risk factors among PD patients.

METHODS

In this cross-sectional study, a total of 114 PD patients with a minimum of 3 months of PD treatment were enrolled. Serum Gal-3 levels were quantified using an enzyme-linked immunosorbent assay. The data of patients with Gal-3 levels higher and lower than 26.744 pg/ml were compared using Mann-Whitney U tests or t tests. Pearson's correlation or Spearman's correlation analysis and multivariate regression were used to assess the associations between the known risk factors for CVD and Gal-3.

RESULTS

In comparison to the inter-group baseline data, the low Gal-3 group exhibited a higher glomerular filtration rate (GFR). Gal-3 levels correlate positively with PD duration, B-type natriuretic peptide (BNP), growth differentiation factor 15 (GDF-15), interventricular septal thickness in diastolic (IVST), and left ventricular mass index (LVMI). Conversely, Gal-3 exhibited a negative correlation with albumin levels. Multivariate linear regression analysis demonstrated a positive correlation between Gal-3 levels and BNP, GDF-15, PD duration, IVST and LVMI. Gal-3 levels were negatively correlated with albumin levels.

CONCLUSIONS

Gal-3 was strongly associated with BNP, GDF-15, IVST and LVMI in patients undergoing PD treatment. Prospective studies should be carried out to determine whether Gal-3 can be a promising biomarker in predicting increased risk of adverse cardiovascular events in PD patients.

Plasma proteins associated with plant-based diets: Results from the Atherosclerosis Risk in Communities (ARIC) study and Framingham Heart Study (FHS)

BACKGROUND & AIMS

Plant-based diets are associated with a lower risk of chronic diseases. Large-scale proteomics can identify objective biomarkers of plant-based diets, and improve our understanding of the pathways that link plant-based diets to health outcomes. This study investigated the plasma proteome of four different plant-based diets [overall plant-based diet (PDI), provegetarian diet, healthful plant-based diet (hPDI), and unhealthful plant-based diet (uPDI)] in the Atherosclerosis Risk in Communities (ARIC) Study and replicated the findings in the Framingham Heart Study (FHS) Offspring cohort.

METHODS

ARIC Study participants at visit 3 (1993-1995) with completed food frequency questionnaire (FFQ) data and proteomics data were divided into internal discovery (n = 7690) and replication (n = 2543) data sets. Multivariable linear regression was used to examine associations between plant-based diet indices (PDIs) and 4955 individual proteins in the discovery sample. Then, proteins that were internally replicated in the ARIC Study were tested for external replication in FHS (n = 1358). Pathway overrepresentation analysis was conducted for diet-related proteins. C-statistics were used to predict if the proteins improved prediction of plant-based diet indices beyond participant characteristics.

RESULTS

In ARIC discovery, a total of 837 diet-protein associations (PDI = 233; provegetarian = 182; hPDI = 406; uPDI = 16) were observed at false discovery rate (FDR) < 0.05. Of these, 453 diet-protein associations (PDI = 132; provegetarian = 104; hPDI = 208; uPDI = 9) were internally replicated. In FHS, 167/453 diet-protein associations were available for external replication, of which 8 proteins (PDI = 1; provegetarian = 0; hPDI = 8; uPDI = 0) replicated. Complement and coagulation cascades, cell adhesion molecules, and retinol metabolism were over-represented. C-C motif chemokine 25 for PDI and 8 proteins for hPDI modestly but significantly improved the prediction of these indices individually and collectively (P value for difference in C-statistics<0.05 for all tests).

CONCLUSIONS

Using large-scale proteomics, we identified potential candidate biomarkers of plant-based diets, and pathways that may partially explain the associations between plant-based diets and chronic conditions.

Assessment and Risk Prediction of Chronic Kidney Disease and Kidney Fibrosis Using Non-Invasive Biomarkers

Effective management of chronic kidney disease (CKD), a major health problem worldwide, requires accurate and timely diagnosis, prognosis of progression, assessment of therapeutic efficacy, and, ideally, prediction of drug response. Multiple biomarkers and algorithms for evaluating specific aspects of CKD have been proposed in the literature, many of which are based on a small number of samples. Based on the evidence presented in relevant studies, a comprehensive overview of the different biomarkers applicable for clinical implementation is lacking. This review aims to compile information on the non-invasive diagnostic, prognostic, and predictive biomarkers currently available for the management of CKD and provide guidance on the application of these biomarkers. We specifically focus on biomarkers that have demonstrated added value in prospective studies or those based on prospectively collected samples including at least 100 subjects. Published data demonstrate that several valid non-invasive biomarkers of potential value in the management of CKD are currently available.

Association of Urine Galectin-3 With Cardiorenal Outcomes in Patients With Heart Failure

BACKGROUND AND OBJECTIVES

Approaches to distinguishing pathological cardiorenal dysfunction in heart failure (HF) from functional/hemodynamically mediated changes in serum creatinine are needed. We investigated urine galectin-3 as a candidate biomarker of renal fibrosis and a prognostic indicator of cardiorenal dysfunction phenotypes.

METHODS

We measured urine galectin-3 in 2 contemporary HF cohorts: the Yale Transitional Care Clinic (YTCC) cohort (n = 132) and the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial (n = 434). We assessed the association of urine galectin-3 with all-cause mortality in both cohorts and the association with an established marker of renal tissue fibrosis, urinary amino-terminal propeptide of type III procollagen (PIIINP) in TOPCAT.

RESULTS

In the YTCC cohort, there was significant effect modification between higher urine galectin-3 and lower estimated glomerular filtration rates (eGFRs) (Pinteraction = 0.046), such that low eGFR levels had minimal prognostic importance if urine galectin-3 levels were low, but they were important and indicated high risk if urine galectin-3 levels were high. Similar observations were noted in the TOPCAT study (Pinteraction = 0.002). In TOPCAT, urine galectin-3 also positively correlated with urine PIIINP at both baseline (r = 0.43; P < 0.001) and at 12 months (r = 0.42; P < 0.001).

CONCLUSIONS

Urine galectin-3 levels correlated with an established biomarker of renal fibrosis in 2 cohorts and was able to differentiate high- vs low-risk phenotypes of chronic kidney disease in HF. These proof-of-concept results indicate that additional biomarker research to differentiate cardiorenal phenotypes is warranted.

Glucocorticoid- and pioglitazone-induced proteinuria reduction in experimental NS both correlate with glomerular ECM modulation

Idiopathic nephrotic syndrome (NS) is a common glomerular disease. Although glucocorticoids (GC) are the primary treatment, the PPARγ agonist pioglitazone (Pio) also reduces proteinuria in patients with NS and directly protects podocytes from injury. Because both drugs reduce proteinuria, we hypothesized these effects result from overlapping transcriptional patterns. Systems biology approaches compared glomerular transcriptomes from rats with PAN-induced NS treated with GC vs. Pio and identified 29 commonly regulated genes-of-interest, primarily involved in extracellular matrix (ECM) remodeling. Correlation with clinical idiopathic NS patient datasets confirmed glomerular ECM dysregulation as a potential mechanism of injury. Cellular deconvolution in silico revealed GC- and Pio-induced amelioration of altered genes primarily within podocytes and mesangial cells. While validation studies are indicated, these analyses identified molecular pathways involved in the early stages of NS (prior to scarring), suggesting that targeting glomerular ECM dysregulation may enable a future non-immunosuppressive approach for proteinuria reduction in idiopathic NS.

Natural products in traditional Chinese medicine: molecular mechanisms and therapeutic targets of renal fibrosis and state-of-the-art drug delivery systems

Renal fibrosis (RF) is the end stage of several chronic kidney diseases. Its series of changes include excessive accumulation of extracellular matrix, epithelial-mesenchymal transition (EMT) of renal tubular cells, fibroblast activation, immune cell infiltration, and renal cell apoptosis. RF can eventually lead to renal dysfunction or even renal failure. A large body of evidence suggests that natural products in traditional Chinese medicine (TCM) have great potential for treating RF. In this article, we first describe the recent advances in RF treatment by several natural products and clarify their mechanisms of action. They can ameliorate the RF disease phenotype, which includes apoptosis, endoplasmic reticulum stress, and EMT, by affecting relevant signaling pathways and molecular targets, thereby delaying or reversing fibrosis. We also present the roles of nanodrug delivery systems, which have been explored to address the drawback of low oral bioavailability of natural products. This may provide new ideas for using natural products for RF treatment. Finally, we provide new insights into the clinical prospects of herbal natural products.

Kidney fibrosis: Emerging diagnostic and therapeutic strategies

An increasing number of patients worldwide suffers from chronic kidney disease (CKD). CKD is accompanied by kidney fibrosis, which affects all compartments of the kidney, i.e., the glomeruli, tubulointerstitium, and vasculature. Fibrosis is the best predictor of progression of kidney diseases. Currently, there is no specific anti-fibrotic therapy for kidney patients and invasive renal biopsy remains the only option for specific detection and quantification of kidney fibrosis. Here we review emerging diagnostic approaches and potential therapeutic options for fibrosis. We discuss how translational research could help to establish fibrosis-specific endpoints for clinical trials, leading to improved patient stratification and potentially companion diagnostics, and facilitating and optimizing development of novel anti-fibrotic therapies for kidney patients.

Validation of eGFR for Detecting Associations Between Serum Protein Biomarkers and Subsequent GFR Decline

SIGNIFICANCE STATEMENT

eGFR from creatinine, cystatin C, or both has been primarily used in search of biomarkers for GFR decline. Whether the relationships between biomarkers and eGFR decline are similar to associations with measured GFR (mGFR) decline has not been investigated. This study revealed that some biomarkers showed statistically significant different associations with eGFR decline compared with mGFR decline, particularly for eGFR from cystatin C. The findings indicate that non-GFR-related factors, such as age, sex, and body mass index, influence the relationship between biomarkers and eGFR decline. Therefore, the results of biomarker studies using eGFR, particularly eGFRcys, should be interpreted with caution and perhaps validated with mGFR.

BACKGROUND

Several serum protein biomarkers have been proposed as risk factors for GFR decline using eGFR from creatinine or cystatin C. We investigated whether eGFR can be used as a surrogate end point for measured GFR (mGFR) when searching for biomarkers associated with GFR decline.

METHODS

In the Renal Iohexol Clearance Survey, GFR was measured with plasma iohexol clearance in 1627 individuals without diabetes, kidney, or cardiovascular disease at baseline. After 11 years of follow-up, 1409 participants had one or more follow-up GFR measurements. Using logistic regression and interval-censored Cox regression, we analyzed the association between baseline levels of 12 serum protein biomarkers with the risk of accelerated GFR decline and incident CKD for both mGFR and eGFR.

RESULTS

Several biomarkers exhibited different associations with eGFR decline compared with their association with mGFR decline. More biomarkers showed different associations with eGFRcys decline than with eGFRcre decline. Most of the different associations of eGFR decline versus mGFR decline remained statistically significant after adjustment for age, sex, and body mass index, but several were attenuated and not significant after adjusting for the corresponding baseline mGFR or eGFR.

CONCLUSIONS

In studies of some serum protein biomarkers, eGFR decline may not be an appropriate surrogate outcome for mGFR decline. Although the differences from mGFR decline are attenuated by adjustment for confounding factors in most cases, some persist. Therefore, proposed biomarkers from studies using eGFR should preferably be validated with mGFR.

Cardiorenal Syndrome: A Literature Review

Cardiorenal syndrome (CRS) is a condition characterized by the intricate two-way relationship between the heart and kidneys, which can lead to acute or chronic dysfunction in these organs. The interplay between cardiorenal connectors and both hemodynamic and non-hemodynamic factors is crucial to understanding this syndrome. The clinical importance of these interactions is evident in the changes observed in hemodynamic factors, neurohormonal markers, and inflammatory processes. Identifying and understanding biomarkers associated with CRS is valuable for early detection and enabling intervention before significant organ dysfunction occurs. This comprehensive review focuses on the clinical significance of biomarkers in the diagnosis, prognosis, and management of CRS. Finally, it highlights the necessity for further advancements in managing this condition.

Cardiac markers and cardiovascular disease in chronic kidney disease

Cardiovascular disease (CVD) is prevalent in patients with chronic kidney disease (CKD) and it is responsible for approximately half of all CKD-related deaths. CVDs are the primary cause of death in hemodialysis patients due to major adverse cardiovascular events. Therefore, better approaches for differentiating chronic hemodialysis patients at higher cardiovascular risk will help physicians improve clinical outcomes. Hence, there is an urgent need to discover feasible and reliable cardiac biomarkers to improve diagnostic accuracy, reflect myocardial injury, and identify high-risk patients. Numerous biomarkers that have significant prognostic value with respect to adverse CVD outcomes in the setting of mild to severe CKD have been identified. Therefore, a better understanding of the positive clinical impact of cardiac biomarkers on CVD patient outcomes is an important step toward prevention and improving treatment in the future. In this review, we address the relationship between cardiovascular biomarkers and CKD treatment strategies to elucidate the underlying importance of these biomarkers to patient outcomes.

Connection between Cardiac Fibrosis Biomarkers and Echocardiography Parameters in Advanced Chronic Kidney Disease Patients

BACKGROUND

Myocardial fibrosis represents a mainstay pathway in the pathophysiology of uremic cardiomyopathy. This process leads to structural and functional changes in the heart, which can be detected by echocardiography. The purpose of our study was to determine the association between four echocardiographic parameters (ejection fraction (EF), global longitudinal strain (GLS), mean E/e' ratio, and left atrial volume indexed) and biomarkers associated with cardiac fibrosis, such as procollagen type I carboxy-terminal propeptide (PICP), procollagen type III N-terminal peptide (P3NP), and galectin-3 (Gal-3) in patients with end-stage renal disease (ESRD).

METHODS

140 patients with ESRD were enrolled and investigated by echocardiography and the serum levels of the aforementioned biomarkers were determined at baseline.

RESULTS

The mean EF was 53.63 ± 8%, the mean GLS was -10.2 ± 5.3%, the mean E/e' ratio was 9.8 ± 4.3, and the mean left atrial volume indexed (LAVI) was 45.8 ± 14.2 mL/m². The average levels for PICP, P3NP, and Gal-3 were 457.2 ± 240 µg/L, 242 ± 199.9 µg/L, and 10.7 ± 3.7 ng/mL, respectively. In regression analysis, PICP was strongly associated with all four echocardiographic parameters (EF: p = 0.0002, R² = 0.69; GLS: p = 0.00001, R² = 0.81; mean E/e': p = 0.00002; R² = 0.89; LAVI: p = 0.003; R² = 0.73). P3NP and Gal-3 were only associated with the EF (p = 0.01, R² = 0.31 and p = 0.02; R² = 0.35, respectively).

CONCLUSION

Our study evidenced that PICP, a collagen-derived biomarker, is associated with important echocardiography parameters, suggesting that it can serve as an indicator of the presence of subclinical systolic and diastolic dysfunction in patients with advanced CKD.

Kidney fibrosis: from mechanisms to therapeutic medicines

Chronic kidney disease (CKD) is estimated to affect 10-14% of global population. Kidney fibrosis, characterized by excessive extracellular matrix deposition leading to scarring, is a hallmark manifestation in different progressive CKD; However, at present no antifibrotic therapies against CKD exist. Kidney fibrosis is identified by tubule atrophy, interstitial chronic inflammation and fibrogenesis, glomerulosclerosis, and vascular rarefaction. Fibrotic niche, where organ fibrosis initiates, is a complex interplay between injured parenchyma (like tubular cells) and multiple non-parenchymal cell lineages (immune and mesenchymal cells) located spatially within scarring areas. Although the mechanisms of kidney fibrosis are complicated due to the kinds of cells involved, with the help of single-cell technology, many key questions have been explored, such as what kind of renal tubules are profibrotic, where myofibroblasts originate, which immune cells are involved, and how cells communicate with each other. In addition, genetics and epigenetics are deeper mechanisms that regulate kidney fibrosis. And the reversible nature of epigenetic changes including DNA methylation, RNA interference, and chromatin remodeling, gives an opportunity to stop or reverse kidney fibrosis by therapeutic strategies. More marketed (e.g., RAS blockage, SGLT2 inhibitors) have been developed to delay CKD progression in recent years. Furthermore, a better understanding of renal fibrosis is also favored to discover biomarkers of fibrotic injury. In the review, we update recent advances in the mechanism of renal fibrosis and summarize novel biomarkers and antifibrotic treatment for CKD.

Serum Galectin-3 and Mucin-1 (CA15-3) in Relation to Renal Function in Untreated Chinese Patients

BACKGROUND

Galectin-3 is a multi-functional lectin protein and a ligand of mucin-1 (CA15-3), and has been linked to renal fibrosis in animal models and renal function in humans. However, no population study has ever explored the associations with both ligand and receptor. We therefore investigate the independent association of renal function with serum galectin-3 and mucin-1 (CA15-3) in untreated Chinese patients.

METHODS

The study participants were outpatients who were suspected of hypertension, but had not been treated with antihypertensive medication. Serum galectin-3 and mucin-1 (CA15-3) concentrations were both measured by the enzyme-linked immunosorbent assay (ELISA) method. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine by the use of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

The 1,789 participants included 848 (47.4%) men. Mean (±SD) age was 51.3 ± 10.7 years. Multiple regression analyses showed that eGFR was significantly associated with serum galectin-3 and mucin-1 (CA15-3) concentration (0.68 and 1.32 ml/min/1.73 m2 decrease per 1-SD increase in log transformed serum galectin-3 and mucin-1 (CA15-3) concentration, respectively; P ≤ 0.006). The association of eGFR with serum mucin-1 (CA15-3) concentration was significantly stronger in the overweight (BMI 24.0-27.9 kg/m2) and obese (BMI ≥ 28.0 kg/m2) than in normal weight subjects (BMI < 24.0 kg/m2, P for interaction 0.018). Path analysis showed that serum galectin-3 concentration had both a direct (P = 0.016) and a mucin-1 mediated indirect effect (P = 0.014) on eGFR.

CONCLUSIONS

Both circulating galectin-3 and mucin-1 (CA15-3) were significantly associated with renal function. The role of galectin-3 on renal function might be partially via mucin-1.

The potential roles of galectin-3 in AKI and CKD

Acute kidney injury (AKI) is a common condition with high morbidity and mortality, and is associated with the development and progression of chronic kidney disease (CKD). The beta-galactoside binding protein galectin-3 (Gal3), with its proinflammatory and profibrotic properties, has been implicated in the development of both AKI and CKD. Serum Gal3 levels are elevated in patients with AKI and CKD, and elevated Gal3 is associated with progression of CKD. In addition, Gal3 is associated with the incidence of AKI among critically ill patients, and blocking Gal3 in murine models of sepsis and ischemia-reperfusion injury results in significantly lower AKI incidence and mortality. Here we review the role of Gal3 in the pathophysiology of AKI and CKD, as well as the therapeutic potential of targeting Gal3.

Right Heart Function in Cardiorenal Syndrome

PURPOSE OF REVIEW

Since CRS is critically dependent on right heart function and involved in interorgan crosstalk, assessment and monitoring of both right heart and kidney function are of utmost importance for clinical outcomes. This systematic review aims to comprehensively report on novel diagnostic and therapeutic paradigms that are gaining importance for the clinical management of the growing heart failure population suffering from CRS.

RECENT FINDINGS

Cardiorenal syndrome (CRS) in patients with heart failure is associated with poor outcome. Although systemic venous congestion and elevated central venous pressure have been recognized as main contributors to CRS, they are often neglected in clinical practice. The delicate hemodynamic balance in CRS is particularly determined by the respective status of the right heart. The consideration of hemodynamic and CRS profiles is advantageous in tailoring treatment for better preservation of renal function. Assessment and monitoring of right heart and renal function by known and emerging tools like renal Doppler ultrasonography or new biomarkers may have direct clinical implications.

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.

Plasma galectin-3 concentration and estimated glomerular filtration rate in patients with type 2 diabetes with and without albuminuria

This study aimed to investigate the association between galectin-3 concentration and estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes mellitus (T2DM) with and without albuminuria. In this cross-sectional study, we examined 334 patients with T2DM. The eGFR was calculated using a creatinine-based formula (eGFR_crea) and a combined creatinine-cystatin C equation (eGFR_crea-cyst). The participants were categorized into two groups based on the urinary albumin-to-creatinine ratio (UACR): patients without albuminuria (UACR < 30 mg/g) and those with albuminuria (UACR ≥ 30 mg/g). Greater concentrations of plasma galectin-3 were associated with lower eGFR_crea-cyst and eGFR_crea levels in patients with and without albuminuria. Plasma galectin-3 concentrations were negatively correlated with eGFR_crea-cyst in patients with normoalbuminuria and albuminuria (γ = − 0.405, P < 0.001; γ = − 0.525, P < 0.001, respectively). Galectin-3 concentrations were significantly associated with eGFR_crea-cyst after adjusting for sex, age, and other confounding factors, including UACR as a categorical or continuous variable in multiple regression analyses (β = − 0.294, 95% CI − 70.804 to − 41.768, P < 0.001; β = − 0.265, 95% CI − 65.192 to − 36.550, P < 0.001, respectively). Likewise, when eGFR_crea-cyst was treated in place of eGFR_crea, this result was replicated in the correlation and regression analyses. Galectin-3 concentration was negatively associated with eGFR in patients with T2DM, independent of albuminuria status.

The Prognostic Value of Cardiac Biomarkers in Patients with Acute Myocardial Infarction during and after Hospitalization

Background

Myocardial infarction (MI) carries a strong risk of death and the development of major adverse cardiovascular events (MACE). A number of biomarkers have been proposed for risk stratification among patients with MI. The aim of this study was to determine whether elevated galectin-3 and midregional-pro atrial natriuretic peptide (MR-proANP) levels can be used as predictors of MACE in patients with acute myocardial infarction (AMI).

Methods

Plasma levels of galectin-3 and MR-proANP were collected from 96 patients following their first AMI hospitalised in our clinic over the course of a year. Samples were taken on admission, and on the first and fifth day of hospitalization. During hospitalization, all patients were followed up for the occurrence of early major adverse cardiac events (MACE), defined as sudden cardiac arrest, new onset atrial fibrillation and need to use pressor amines. All patients were also followed up twelve months after AMI for the occurrence of late MACE defined as cardiac death, reinfarction and need for unscheduled PCI.

Results

Patients who experienced early MACE had significantly higher galectin-3 and MR-proANP levels assessed on admission (p = 0.007, p = 0.003). ROC curve analysis found also galectin-3 concentration assessed on admission to be a strong predictor of late MACE (AUC = 0.75, p = 0.0061). MRproANP does not appear to have any value in predicting late MACE.

Conclusions

A high concentration of galectin-3 and MR-proANP observed on admission in patients with acute myocardial infarction has significant prognostic value: it may identify patients at high risk of early adverse cardiac events after AMI. In contrast to MR-proANP, a high concentration of galectin-3 observed on admission may also identify patients at high risk of late MACE.

Galectin 3 (LGALS3) Gene Polymorphisms Are Associated with Biochemical Parameters and Primary Disease in Patients with End-Stage Renal Disease in Serbian Population

Galectin 3 plays a significant role in the development of chronic renal failure, particularly end-stage renal disease (ESRD). The aim of our study was to investigate the association between Gal-3 and biochemical parameters and primary disease in ESRD patients, by exploring the polymorphisms LGALS3 rs4644, rs4652, and rs11125. A total of 108 ESRD patients and 38 healthy controls were enrolled in the study. Genotyping of LGALS3 gene rs4644, rs4652, and rs11125 polymorphisms was performed by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). By multivariate logistic regression analysis, we found that LGALS3 rs4644 CC and rs4652 AA genotypes were significantly associated with a higher risk for lower hemoglobin, higher level of parathyroid hormone, and also occurrence of diabetes mellitus and arterial hypertension. The CAA haplotype was significantly more common in patients with diabetes, low hemoglobin level, and normal PTH level. It has been observed as well that the ACT haplotype was more common in patients with low glomerular filtration, low PTH, and normal hemoglobin level. We found that the LGALS3 rs4644 and rs4652 gene polymorphism may be involved in the pathogenesis and appearance of complications in ESRD patients and thus could be considered a new genetic risk factor in this population.

Galectin-3 as a Marker of Cardiorenal Syndrome in Patients with Chronic Heart Failure

Aim. To assess the effect of renal dysfunction on the galectin-3 level in patients with chronic heart failure (HF) with preserved, intermediate and reduced left ventricular ejection fraction (EF).Material and methods. Along with a clinical examination, 69 patients with HF (NYHA class II-IV) underwent tests for the level of NT-proBNP and galectin-3 in serum using enzyme immunoassay.Results. Study participants were divided into 3 groups: 23 patients with preserved EF (HFpEF), 26 patients with midrange EF (HFmrEF), 20 patients with reduced EF (HFrEF). There was a trend to increase the concentration of galectin-3 with increase in NT-proBNP level. Correlation analysis showed significant feedback (r=−0.41, p<0.05) between galectin-3 and EF only in patients with preserved systolic function. In the same group of HFpEF patients, the maximum serum galectin-3 level was 10.5 [6.5; 14.5] ng/ml. Serum galectin-3 level showed negative correlated with the GFR in patients with CHF (r=−0.513, p<0.05). In patients with HF and glomerular filtration rate (GFR) <60 ml/min/1.73 m2 it was higher than in patients with GFR>60 ml/min/1.72 m2 (9 [5.3; 12.6] ng/mL vs 11.8 [6.2; 15.3] ng/mL, p<0.05). According to the ROC-analysis data, galectin-3 level >10.3 ng/ml indicates a high risk of chronic kidney disease stage 3-4 stage development (sensitivity 60%, specificity 75%) and can be considered as a risk factor for development of cardiorenal syndrome in HF patients.Conclusion. Galectin-3 level in patients with HF is more influenced by the degree of reduction in GFR rather than the left ventricular systolic function impairment.

Galectin-3 in Kidney Diseases: From an Old Protein to a New Therapeutic Target

Galectin-3 (Gal-3) is a 30KDa lectin implicated in multiple pathophysiology pathways including renal damage and fibrosis. Gal-3 binds β-galactoside through its carbohydrate-recognition domain. From intra-cellular to extra-cellular localization, Gal-3 has multiple roles including transduction signal pathway, cell-to-cell adhesion, cell to extracellular matrix adhesion, and immunological chemoattractant protein. Moreover, Gal-3 has also been linked to kidney disease in both preclinical models and clinical studies. Gal-3 inhibition appears to improve renal disease in several pathological conditions, thus justifying the development of multiple drug inhibitors. This review aims to summarize the latest literature regarding Gal-3 in renal pathophysiology, from its role as a biomarker to its potential as a therapeutic agent.

Urinary Galectin-3 as a Novel Biomarker for the Prediction of Renal Fibrosis and Kidney Disease Progression

Plasma galectin-3 (Gal-3) is associated with organ fibrosis, but whether urinary Gal-3 is a potential biomarker of kidney disease progression has never been explored. Between 2018 and 2021, we prospectively enrolled 280 patients who underwent renal biopsy and were divided into three groups based on their urinary Gal-3 levels (<354.6, 354.6−510.7, and ≥510.8 pg/mL) to assess kidney disease progression (defined as ≥40% decline in the estimated glomerular filtration rate or end-stage renal disease) and renal histology findings. Patients in the highest urinary Gal-3 tertile had the lowest eGFRs and highest proteinuria levels. In multivariate Cox regression models, patients in the highest tertile had the highest risk of kidney disease progression (adjusted hazard ratio, 4.60; 95% confidence interval, 2.85−7.71) compared to those in the lowest tertile. Higher urinary Gal-3 levels were associated with more severe renal fibrosis. Intrarenal mRNA expression of LGALS3 (Gal-3-encoded gene) was most correlated with the renal stress biomarkers (IGFBP7 and TIMB2), renal function biomarkers (PTGDS) and fibrosis-associated genes (TGFB1). The urinary Gal-3 level may be useful for the identification of patients at high risk of kidney disease progression and renal fibrosis, and for the early initiation of treatments for these patients.

Galectin-3 as an independent prognostic factor after heart transplantation

BACKGROUND

Galectin-3 (GAL3) is linked to the prognosis of patients with heart failure and after heart transplantation (HTx). We assessed the prognostic role of GAL3 in a long-term follow-up after HTx.

METHODS

HTx patients (N = 121) were evaluated in a single-center, noninterventional, prospective, observational study. The median follow-up was 96 months (2,942 days, interquartile range (IQR) 2,408-3,264 days), and 40 patients died. GAL3 was measured before HTx, +10 days after HTx, and during the first posttransplant year. Survival analysis (all-cause mortality) was performed with adjustments for clinical and laboratory variables.

RESULTS

The median pretransplant GAL3 level was 18.0 μg/L (IQR 14.0-25.9), and higher values were associated with older age, worse kidney function, left ventricular assist device use before HTx, a higher IMPACT score and mortality. Increased pretransplant GAL3 predicted shorter survival time (HR 2.05, 95% CI 1.09-3.85, p<0.05). Similar prognostic power had GAL3 on the 10th posttransplant day (HR 2.03, 95% CI 1.08-3.82, p<0.05). GAL3 was an independent predictor of death after adjustment for clinical variables (age, infection, diabetes, smoking, IMPACT score, troponin).

CONCLUSIONS

GAL3 was significantly associated with all-cause mortality after adjusting for clinical and laboratory variables and may serve as an additional prognostic biomarker. This article is protected by copyright. All rights reserved.

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.

Identification of Galectin-3 as Potential Biomarkers for Renal Fibrosis by RNA-Sequencing and Clinicopathologic Findings of Kidney Biopsy

Background: Galectin-3 (Gal-3) is a multifunctional glycan-binding protein shown to be linked to chronic inflammation and fibrogenesis. Plasma Gal-3 is associated with proteinuria and renal dysfunction, but its role has never been confirmed with kidney biopsy results. In our study, we aimed to explore the expression of Gal-3 in biopsy-proven patients, and we tested the hypothesis that chronic kidney disease (CKD) leads to upregulation of plasma Gal-3 expression in corresponding biopsy findings and RNA sequencing analysis. Method: In 249 patients (male/female: 155/94, age: 57.2 ± 16.3 years) who underwent kidney biopsy, plasma levels of Gal-3 were measured to estimate the association of renal fibrosis. Relationships between plasma Gal-3 levels, estimated glomerular filtration rate (eGFR) and renal histology findings were also assessed. We further examined the gene expression of Gal-3 in RNA-sequencing analysis in biopsy-proven patients. Results: Compared to patients without CKD, CKD patients had higher levels of plasma Gal-3 (1,016.3 ± 628.1 pg/mL vs. 811.6 ± 369.6 pg/ml; P = 0.010). Plasma Gal-3 was inversely correlated with eGFR (P = 0.005) but not with proteinuria. Higher Gal-3 levels were associated with interstitial fibrosis, tubular atrophy and vascular intimal fibrosis. RNA-sequencing analysis showed the upregulation of Gal-3 in fibrotic kidney biopsy samples, and the differentially expressed genes were mainly enhanced in immune cell activation and the regulation of cell-cell adhesion. Conclusions: Plasma Gal-3 levels are inverse correlated with eGFR but positively correlated with renal fibrosis, which may be involved in the immune response and associated pathways. These findings support the role of Gal-3 as a predictive marker of renal fibrosis.

Galectin-3 is linked to peripheral artery disease severity, and urinary excretion is associated with long-term mortality

BACKGROUND AND AIMS

Galectin-3 (Gal-3) is a biomarker involved in fibrosis and vascular inflammation. Gal-3 has been linked to chronic kidney disease (CKD) and patients with peripheral artery disease (PAD). Conflicting reports exist about the relevance of Gal-3 in PAD. The study aims to elucidate a possible link between serum and urinary Gal-3 and long-term survival in PAD patients without critical limb ischemia and mild to moderate CKD.

METHODS

Galectin-3 (Gal-3) was measured in serum (n = 311) and urine (n = 266) of PAD patients (age 69 (62-77) years) by bead-based multiplex assay. Urinary Gal-3 concentration was normalized to urine creatinine (cr) levels. Mortality data were retrieved from the Austrian central death registry after a median observation period of 9.2 years. Survival analyses were performed by the Kaplan-Meier method and Cox-regression.

RESULTS

Serum Gal-3 was higher in patients with claudication symptoms (p = 0.001) and correlated inversely with the patients' ankle-brachial index (R = -0.168, p = 0.009). Serum Gal-3 and urinary Gal-3 (uGal-3/cr) were associated with the estimated glomerular filtration rate (R = -0.359, p < 0.001; R = -0.285, p < 0.001). Serum Gal-3 was not linked to all-cause mortality [HR 1.17 (CI 0.96-1.42)] over 9.2 years. However, uGal-3/cr was associated with all-cause mortality [HR 1.60 (CI 1.31-1.95)]. This association sustained multivariable adjustment for cardiovascular risk factors and renal function [HR 1.71 (CI 1.35-2.17)].

CONCLUSIONS

This study is the first to show an association of uGal-3/cr and long-term mortality in patients with PAD. Gal-3 was not predictive of long-term mortality but seems to be a marker of PAD severity in patients without critical limb ischemia.

Biomarkers in Cardiorenal Syndrome

Cardiorenal syndrome is a clinical manifestation of the bidirectional interaction between the heart and kidney diseases. Over the last years, in patients with cardiovascular diseases, several biomarkers have been studied in order to better assess renal function as well as to identify patients prone to experiencing chronic or acute worsening of renal function. The aim of this review is to focus on the possible clinical usefulness of the most recent biomarkers in the setting of cardiorenal syndrome.

Mesenchymal stem cells ameliorate renal fibrosis by galectin-3/Akt/GSK3β/Snail signaling pathway in adenine-induced nephropathy rat

BACKGROUND

Tubulointerstitial fibrosis (TIF) is one of the main pathological features of various progressive renal damages and chronic kidney diseases. Mesenchymal stromal cells (MSCs) have been verified with significant improvement in the therapy of fibrosis diseases, but the mechanism is still unclear. We attempted to explore the new mechanism and therapeutic target of MSCs against renal fibrosis based on renal proteomics.

METHODS

TIF model was induced by adenine gavage. Bone marrow-derived MSCs was injected by tail vein after modeling. Renal function and fibrosis related parameters were assessed by Masson, Sirius red, immunohistochemistry, and western blot. Renal proteomics was analyzed using iTRAQ-based mass spectrometry. Further possible mechanism was explored by transfected galectin-3 gene for knockdown (Gal-3 KD) and overexpression (Gal-3 OE) in HK-2 cells with lentiviral vector.

RESULTS

MSCs treatment clearly decreased the expression of α-SMA, collagen type I, II, III, TGF-β1, Kim-1, p-Smad2/3, IL-6, IL-1β, and TNFα compared with model rats, while p38 MAPK increased. Proteomics showed that only 40 proteins exhibited significant differences (30 upregulated, 10 downregulated) compared MSCs group with the model group. Galectin-3 was downregulated significantly in renal tissues and TGF-β1-induced rat tubular epithelial cells and interstitial fibroblasts, consistent with the iTRAQ results. Gal-3 KD notably inhibited the expression of p-Akt, p-GSK3β and snail in TGF-β1-induced HK-2 cells fibrosis. On the contrary, Gal-3 OE obviously increased the expression of p-Akt, p-GSK3β and snail.

CONCLUSION

The mechanism of MSCs anti-renal fibrosis was probably mediated by galectin-3/Akt/GSK3β/Snail signaling pathway. Galectin-3 may be a valuable target for treating renal fibrosis.

Urinary proteomics for kidney dysfunction: insights and trends

Introduction: Kidney dysfunction poses a high burden on patients and health care systems. Early detection and accurate prediction of kidney disease progression remains a major challenge. Compared to existing clinical parameters, urinary proteomics has the potential to reveal molecular alterations within the kidney that may alter its function before the onset of clinical symptoms. Thus, urinary proteomics has greater prognostic potential for assessment of kidney dysfunction progression.Areas covered: Advances in urinary proteomics for major causes of kidney dysfunction are discussed. The application of urinary extracellular vesicles for studying kidney dysfunction are discussed. Technological advances in urinary proteomics are discussed. The literature was identified using a database search for titles containing 'proteom*' and 'urin*' and published within the past 5 years. Retrieved literature was manually filtered to retain kidney dysfunctions-related studies.Expert opinion: Despite major advances, diagnosis by urinary proteomics has not been fully applied in any clinical settings. This could be attributed to the complex nature of kidney diseases, in addition to the constraints on study power and feasibility of incorporating mass spectrometry techniques in daily routine analysis. Nevertheless, we are confident that advances in urinary proteomics will soon provide superior insights into kidney disease beyond existing clinical parameters.

Galectin-3 N-terminal tail prolines modulate cell activity and glycan-mediated oligomerization/phase separation

Galectin-3 (Gal-3) has a long, aperiodic, and dynamic proline-rich N-terminal tail (NT). The functional role of the NT with its numerous prolines has remained enigmatic since its discovery. To provide some resolution to this puzzle, we individually mutated all 14 NT prolines over the first 68 residues and assessed their effects on various Gal-3-mediated functions. Our findings show that mutation of any single proline (especially P37A, P55A, P60A, P64A/H, and P67A) dramatically and differentially inhibits Gal-3-mediated cellular activities (i.e., cell migration, activation, endocytosis, and hemagglutination). For mechanistic insight, we investigated the role of prolines in mediating Gal-3 oligomerization, a fundamental process required for these cell activities. We showed that Gal-3 oligomerization triggered by binding to glycoproteins is a dynamic process analogous to liquid-liquid phase separation (LLPS). The composition of these heterooligomers is dependent on the concentration of Gal-3 as well as on the concentration and type of glycoprotein. LLPS-like Gal-3 oligomerization/condensation was also observed on the plasma membrane and disrupted endomembranes. Molecular- and cell-based assays indicate that glycan binding-triggered Gal-3 LLPS (or LLPS-like) is driven mainly by dynamic intermolecular interactions between the Gal-3 NT and the carbohydrate recognition domain (CRD) F-face, although NT-NT interactions appear to contribute to a lesser extent. Mutation of each proline within the NT differentially controls NT-CRD interactions, consequently affecting glycan binding, LLPS, and cellular activities. Our results unveil the role of proline polymorphisms (e.g., at P64) associated with many diseases and suggest that the function of glycosylated cell surface receptors is dynamically regulated by Gal-3.

Galectin-3 and Risk of Late Graft Failure in Kidney Transplant Recipients: A 10-year Prospective Cohort Study

BACKGROUND

Galectin-3 may play a causal role in kidney inflammation and fibrosis, which may also be involved in the development of kidney graft failure. With novel galectin-3-targeted pharmacological therapies increasingly coming available, we aimed to investigate whether galectin-3 is associated with risk of late graft failure in kidney transplant recipients (KTR).

METHODS

We studied adult KTR who participated in TransplantLines Insulin Resistance and Inflammation Biobank and Cohort Study, recruited in a university setting (2001-2003). Follow-up was performed for a median of 9.5 (interquartile range, 6.2-10.2) years. Overall and stratified (Pinteraction < 0.05) multivariable-adjusted Cox proportional-hazards regression analyses were performed to study the association of galectin-3 with risk of graft failure (restart of dialysis or retransplantation).

RESULTS

Among 561 KTR (age 52 ± 12 y; 54% males), baseline median galectin-3 was 21.1 (interquartile range, 17.0-27.2) ng/mL. During follow-up, 72 KTR developed graft failure (13, 18, and 44 events over increasing tertiles of galectin-3). Independent of adjustment for donor, recipient, and transplant characteristics, galectin-3-associated with increased risk of graft failure (hazard ratios [HR] per 1 SD change, 2.12; 95% confidence interval [CI], 1.63-2.75; P < 0.001), particularly among KTR with systolic blood pressure ≥140 mmHg (HR, 2.29; 95% CI, 1.80-2.92; P < 0.001; Pinteraction = 0.01) or smoking history (HR, 2.56; 95% CI, 1.95-3.37; P < 0.001; Pinteraction = 0.03). Similarly, patients in the highest tertile of galectin-3 were consistently at increased risk of graft failure.

CONCLUSIONS

Serum galectin-3 levels are elevated in KTR, and independently associated with increased risk of late graft failure. Whether galectin-3-targeted therapies may represent novel opportunities to decrease the long-standing high burden of late graft failure in stable KTR warrants further studies.

Galectin-3 in septic acute kidney injury: a translational study

BACKGROUND

Galectin-3 (Gal-3) is a pleiotropic glycan-binding protein shown to be involved in sepsis and acute kidney injury (AKI). However, its role has never been elucidated in sepsis-associated AKI (S-AKI). We aimed to explore Gal-3's role and its potential utility as a therapeutic target in S-AKI.

METHODS

In 57 patients admitted to the intensive care unit (ICU) with sepsis, serum Gal-3 was examined as a predictor of ICU mortality and development of AKI. In a rat model of S-AKI induced by cecal ligation and puncture (CLP), 7-day mortality and serum Gal-3, Interleukin-6 (IL-6), and creatinine were examined at 2, 8, and 24 hours (h) post-CLP. Two experimental groups received the Gal-3 inhibitor modified citrus pectin (P-MCP) at 400 mg/kg/day and 1200 mg/kg/day, while the control group received water only (n = 18 in each group).

RESULTS

Among 57 patients, 27 developed AKI and 8 died in the ICU. Serum Gal-3 was an independent predictor of AKI (OR = 1.2 [95% CI 1.1-1.4], p = 0.01) and ICU mortality (OR = 1.4 [95% CI 1.1-2.2], p = 0.04) before and after controlling for age, AKI, and acute physiology and chronic health evaluation (APACHE II) score. In the CLP rat experiment, serum Gal-3 peaked earlier than IL-6. Serum Gal-3 was significantly lower in both P-MCP groups compared to control at 2 h post-CLP (400 mg: p = 0.003; 1200 mg: p = 0.002), and IL-6 was significantly lower in both P-MCP groups at all time points with a maximum difference at 24 h post-CLP (400 mg: p = 0.015; 1200 mg: p = 0.02). In the Gal-3 inhibitor groups, 7-day mortality was significantly reduced from 61% in the control group to 28% (400 mg P-MCP: p = 0.03) and 22% (1200 mg P-MCP: p = 0.001). Rates of AKI per RIFLE criteria were significantly reduced from 89% in the control group to 44% in both P-MCP groups (400 mg: p = 0.007; 1200 mg: p = 0.007).

CONCLUSIONS

This translational study demonstrates the importance of Gal-3 in the pathogenesis of S-AKI, and its potential utility as a therapeutic target.

Soluble ST2 and Galectin-3 as Predictors of Chronic Kidney Disease Progression and Outcomes

BACKGROUND

Soluble suppression of tumorigenicity-2 (sST2) and galectin-3, novel biomarkers of heart failure and cardiovascular stress, predict cardiovascular events (CVEs) and mortality. However, their relationship with kidney function and adverse outcomes in CKD are uncertain. The purpose of this study was to determine the association between sST2 and galectin-3 with CKD progression and adverse clinical outcomes.

METHODS

We measured baseline sST2 and galectin-3 levels in the CKD patient cohort at our institution between October 2013 and December 2014. The primary outcome was CKD progression (kidney failure with replacement therapy or ≥50% reduction in estimated glomerular filtration rate from the baseline). The secondary outcome was the composite of CVEs and death. We used a Cox proportional hazards model to evaluate the associations between sST2 and galectin-3 levels, with kidney and clinical outcomes.

RESULTS

In total, 352 patients were enrolled in this study. At baseline, log sST2 and galectin-3 were directly associated with the serum creatinine (Cr) and urine protein-to-Cr ratio. Cox regression analysis showed that the baseline log sST2 level independently predicted CKD progression and composite outcome after adjustment for age, sex, smoking, diabetes mellitus, hypertension, cardiovascular disease, renin-angiotensin system blocker, calcium channel blocker, β-blocker, diuretics, antiplatelet agents, anemia, and hypoalbuminemia. The baseline log galectin-3 level was independently associated with CKD progression, but not with the composite outcome after adjustment for confounding variables.

CONCLUSIONS

Elevated levels of sST2 and galectin-3 are significantly associated with CKD progression, but only sST2 is associated with adverse clinical outcomes.

Elevated levels of soluble ST2 but not galectin-3 are associated with increased risk of mortality in hemodialysis patients

Background

The soluble forms of suppression of tumorigenicity-2 (ST2) and galectin-3 have been proposed as novel biomarkers for cardiac fibrosis and heart failure, as well as predictors of cardiovascular events and mortality. However, there are limited data on the association between soluble ST2 and galectin-3 and clinical outcomes in patients with kidney failure on replacement therapy. To determine this, we examined the associations between soluble ST2 and galectin-3 and all-cause mortality and cardiovascular events in patients on hemodialysis.

Methods

This study included maintenance hemodialysis patients (over 18 years old) who consented to preserve their serum in the Biobank at our institution between March 2014 and March 2015. We used Cox proportional hazards regression analysis to evaluate the associations between soluble ST2, galectin-3 levels, and clinical outcomes. The primary outcome was all-cause mortality, the secondary outcome was cardiovascular disease, and patients were followed for both outcomes until March 2018.

Results

A total of 296 patients were analyzed in this study. The mean age was 57 ± 13 years, and 53.0% were male. Serum concentration of soluble ST2 was significantly associated with higher mortality, after adjustment for confounding factors, but was not associated with cardiovascular disease. Serum galectin-3 level was not independently associated with either outcome after adjustment.

Conclusion

Elevated soluble ST2 is independently associated with an increased risk of mortality, but not with cardiovascular disease, in patients on hemodialysis. Elevated galectin-3 was not associated with mortality or cardiovascular disease.

Fibrosis and Inflammatory Markers and Long-Term Risk of Peripheral Artery Disease: The ARIC Study

OBJECTIVE

Inflammatory markers, such as hs-CRP (high-sensitivity C-reactive protein), have been reported to be related to peripheral artery disease (PAD). Galectin-3, a biomarker of fibrosis, has been linked to vascular remodeling and atherogenesis. However, its prospective association with incident PAD is unknown; as is the influence of inflammation on the association between galectin-3 and PAD. Approach and Results: In 9851 Atherosclerosis Risk in Communities Study participants free of PAD at baseline (1996-1998), we quantified the association of galactin-3 and hs-CRP with incident PAD (hospitalizations with PAD diagnosis [International Classification of Diseases-Ninth Revision: 440.2-440.4] or leg revascularization [eg, International Classification of Diseases-Ninth Revision: 38.18]) as well as its severe form, critical limb ischemia (PAD cases with resting pain, ulcer, gangrene, or leg amputation) using Cox models. Over a median follow-up of 17.4 years, there were 316 cases of PAD including 119 critical limb ischemia cases. Log-transformed galectin-3 was associated with incident PAD (adjusted hazard ratio, 1.17 [1.05-1.31] per 1 SD increment) and critical limb ischemia (1.25 [1.05-1.49] per 1 SD increment). The association was slightly attenuated after further adjusting for hs-CRP (1.14 [1.02-1.27] and 1.22 [1.02-1.45], respectively). Log-transformed hs-CRP demonstrated robust associations with PAD and critical limb ischemia even after adjusting for galectin-3 (adjusted hazard ratio per 1 SD increment 1.34 [1.18-1.52] and 1.34 [1.09-1.65], respectively). The addition of galectin-3 and hs-CRP to traditional atherosclerotic predictors (C statistic of the base model 0.843 [0.815-0.871]) improved the risk prediction of PAD (ΔC statistics, 0.011 [0.002-0.020]).

CONCLUSIONS

Galectin-3 and hs-CRP were independently associated with incident PAD in the general population, supporting the involvement of fibrosis and inflammation in the pathophysiology of PAD.

Associations Between Plasma Immunomodulatory and Inflammatory Mediators With VACS Index Scores Among Older HIV-Infected Adults on Antiretroviral Therapy

The prevalence of age-related comorbidities is increased in people living with HIV, even in those well-controlled on combination antiretroviral therapy (ART). Persistent immune activation and inflammation may play pivotal roles in the pathogenesis; however, the burden of morbidities in the older HIV infected population may be exacerbated and driven by distinct mechanisms. In a cross sectional study of 45 HIV-infected participants 60 years or older, we examined the relationships between 14 immunomodulatory and inflammatory factors and the Veterans Aging Cohort Study (VACS) Index, a metric of multimorbidity and mortality comprised of age, CD4 count, hemoglobin, Fibrosis-4 [FIB-4], and estimated glomerular filtration rate [eGFR], by linear regression analysis. All participants were virally suppressed (<50 HIV RNA copies/mL), on ART, and primarily Caucasian (86.7%), and male (91.1%). Plasma levels of monocyte/macrophage-associated (neopterin, IP-10, sCD163, sCD14, and MCP-1) and glycan-binding immunomodulatory factors (galectin (Gal)-1, Gal-3, and Gal-9) were assessed, as well as inflammatory biomarkers previously linked to the VACS Index (i.e., CRP, cystatin C, TNF-α, TNFRI, IL-6, and D-dimer) for comparison. In regression analysis, higher VACS index scores were associated with higher levels of neopterin, cystatin C, TNFRI, and Gal-9 (all p < 0.05), potentially driven by correlations found with individual VACS components, including age, CD4 count, FIB-4, and eGFR. Gal-9, cystatin C, and TNFRI directly correlated with the extent of multimorbidity. Multiple correlations among markers were observed, suggesting an interplay of overlapping, but distinct, pathways. Collectively, in addition to cystatin C and TNFRI, both galectin-9 and neopterin, independently emerged as novel fluid markers of the VACS Index and burden of comorbidity and may further guide in understanding pathogenic mechanisms of age-related disorders in older HIV-infected individuals on suppressive ART.

Lifestyle, Inflammation, and Vascular Calcification in Kidney Transplant Recipients: Perspectives on Long-Term Outcomes

After decades of pioneering and improvement, kidney transplantation is now the renal replacement therapy of choice for most patients with end-stage kidney disease (ESKD). Where focus has traditionally been on surgical techniques and immunosuppressive treatment with prevention of rejection and infection in relation to short-term outcomes, nowadays, so many people are long-living with a transplanted kidney that lifestyle, including diet and exposure to toxic contaminants, also becomes of importance for the kidney transplantation field. Beyond hazards of immunological nature, a systematic assessment of potentially modifiable-yet rather overlooked-risk factors for late graft failure and excess cardiovascular risk may reveal novel targets for clinical intervention to optimize long-term health and downturn current rates of premature death of kidney transplant recipients (KTR). It should also be realized that while kidney transplantation aims to restore kidney function, it incompletely mitigates mechanisms of disease such as chronic low-grade inflammation with persistent redox imbalance and deregulated mineral and bone metabolism. While the vicious circle between inflammation and oxidative stress as common final pathway of a multitude of insults plays an established pathological role in native chronic kidney disease, its characterization post-kidney transplant remains less than satisfactory. Next to chronic inflammatory status, markedly accelerated vascular calcification persists after kidney transplantation and is likewise suggested a major independent mechanism, whose mitigation may counterbalance the excess risk of cardiovascular disease post-kidney transplant. Hereby, we first discuss modifiable dietary elements and toxic environmental contaminants that may explain increased risk of cardiovascular mortality and late graft failure in KTR. Next, we specify laboratory and clinical readouts, with a postulated role within persisting mechanisms of disease post-kidney transplantation (i.e., inflammation and redox imbalance and vascular calcification), as potential non-traditional risk factors for adverse long-term outcomes in KTR. Reflection on these current research opportunities is warranted among the research and clinical kidney transplantation community.

Oh cystinosin: let me count the ways!

Nephropathic cystinosis is the most common genetic cause of a renal Fanconi syndrome and results from dysfunction of the lysosomal cystine-transporter protein cystinosin. The multiple organ dysfunctions of affected patients were thought to be related to the defective protein, with cystine crystal formation. However, such crystals were not always present when looked for. More recently, study of the biology of cystinosis has expanded to include many other cellular processes that may be pathogenic in the disease, and now galectin-3 can be added to those identified.

Galectins as potential pharmacological targets in renal injuries of diverse etiology

Galectins are carbohydrate-binding proteins, and their importance in renal diseases of diverse etiology has been documented. Amongst different galectins, the role of galectin-3 in the pathophysiology of renal diseases has been well documented. There is an increase in galectin-3 in the circulation as well as on the kidneys in chronic kidney disease patients. The increase in galectin-3 is negatively correlated with a decrease in renal function and overall survival rate. The preclinical studies also correlate the increase in galectin-3 levels with renal dysfunction. Accordingly, scientists have exploited galectin-3 as a potential pharmacological target to improve renal functions in different preclinical models of renal injury. Apart from galectin-3, there have been few studies documenting the role of galectin-1, 8, and 9 in renal diseases. The role of galectin-1 is not clearly identified, and there have been conflicting reports regarding its role in renal diseases. Galectin-8 and 9 impart renoprotective effects as per clinical and preclinical studies, respectively. The present review discusses the role of different galectins in renal diseases of diverse etiology.

Potential biomarkers for early detection of diabetic kidney disease

INTRODUCTION

To assess the potential of galectin-3 and growth differentiation factor-15 (GDF-15) biomarkers for the early detection of diabetic kidney disease (DKD).

METHODOLOGY

This was a cross-sectional study conducted over a period of 1.2 years. Patients were stratified based on estimated glomerular filtration rate (eGFR) and albuminuria level. The receiver operating characteristic (ROC) curve was plotted to assess the diagnostic potential of biomarkers.

RESULTS

A total of 90 patients included in this study. Patients were grouped as normoalbuminuria (30 patients), microalbuminuria (30 patients), and macroalbuminuria (30 patients). Galectin-3 and GDF-15 levels were significantly elevated in T2DM patients with macroalbuminuria (p = <0.05). Higher levels of galectin-3 and GDF-15 were found in patients with poor kidney function (Stage IV-V CKD). Negative correlation was observed between galectin- 3 (r = -0.472) and eGFR (p = 0.000), GDF-15 (r = -0.917) and eGFR (p <0.000). The ROC analysis yielded an area under curve (AUC) of 0.776 (95% CI: 0.677 to 0.875; p = <0.0001) for galectin-3 and an AUC of 0.963 (95% CI: 0.929 to 0.997; p = <0.0001) for GDF-15.

CONCLUSION

In DKD patients the galectin-3 and GDF-15 levels were inversely related to the eGFR which was further confirmed by the ROC curve demonstrating the potential of galectin-3 and GDF-15 as a biomarker.

High-sensitivity Troponin I Predicts Galectin-3 in Chronic Kidney Disease Patients

PURPOSE

Plasma galectin-3 (pG3) regulates inflammation. B-type natriuretic peptide (BNP), high-sensitivity Troponin I (hsTnI), and pG3 concentrations are elevated in chronic kidney disease (CKD) patients. The associations of pG3 with hsTnI/BNP are unclear. We explored the relationship of hsTnI and BNP with pG3 in Asian CKD patients and healthy controls.

METHODS

We retrieved prospectively collected frozen plasma samples from 163 stable CKD patients and 105 healthy controls. BNP, hsTnI and pG3 were assayed. pG3 was assessed for associations with age, gender, ethnicity, blood pressures; height, weight, body mass index (BMI), previously diagnosed CKD, diabetes, hypertension, coronary artery disease, estimated glomerular filtration rate (eGFR); C-reactive protein, beta-trace protein, 24 h urine protein, serum albumin, uric acid and cystatin C. We created two models predicting pG3 using multiple linear regression. Akaike Information Criterion (AIC) was used for comparison. Significance was taken at P < 0.05.

RESULTS

CKD versus healthy participants: mean BMI (28.2 vs. 24.9 kg/m²), median serum creatinine (159 vs. 69 µmol/L; 1.8 vs. 0.78 mg/dL), median eGFR (49 vs. 104 mL/min/1.73m²), median pG3 (29.4 vs. 15.4 ng/mL), median BNP (136 vs. 23 pg/mL), and median hsTnI (12.5 vs. 2.6 pg/mL). By univariate analysis, all variables are associated with pG3 except weight, gender and diagnosis of cerebrovascular or peripheral vascular diseases. A parsimonious model selected for hsTnI, BMI, serum albumin, cystatin C and eGFR (AIC = 77.6).

CONCLUSION

BNP and hsTnI are associated with pG3 in Asian CKD patients. hsTnI is a better predictor of pG3.

Galectin 3 protects from cisplatin-induced acute kidney injury by promoting TLR-2-dependent activation of IDO1/Kynurenine pathway in renal DCs

Strategies targeting cross-talk between immunosuppressive renal dendritic cells (DCs) and T regulatory cells (Tregs) may be effective in treating cisplatin (CDDP)-induced acute kidney injury (AKI). Galectin 3 (Gal-3), expressed on renal DCs, is known as a crucial regulator of immune response in the kidneys. In this study, we investigated the role of Gal-3 for DCs-mediated expansion of Tregs in the attenuation of CDDP-induced AKI. Methods: AKI was induced in CDDP-treated wild type (WT) C57BL/6 and Gal-3 deficient (Gal-3^-/-) mice. Biochemical, histological analysis, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, real-time PCR, magnetic cell sorting, flow cytometry and intracellular staining of renal-infiltrated immune cells were used to determine the differences between CDDP-treated WT and Gal-3^-/- mice. Newly synthesized selective inhibitor of Gal-3 (Davanat) was used for pharmacological inhibition of Gal-3. Recombinant Gal-3 was used to demonstrate the effects of exogenously administered soluble Gal-3 on AKI progression. Pam3CSK4 was used for activation of Toll-like receptor (TLR)-2 in DCs. Cyclophosphamide or anti-CD25 antibody were used for the depletion of Tregs. 1-Methyl Tryptophan (1-MT) was used for pharmacological inhibition of Indoleamine 2,3-dioxygenase-1 (IDO1) in TLR-2-primed DCs which were afterwards used in passive transfer experiments. Results: CDDP-induced nephrotoxicity was significantly more aggravated in Gal-3^-/- mice. Significantly reduced number of immunosuppressive TLR-2 and IDO1-expressing renal DCs, lower serum levels of KYN, decreased presence of IL-10-producing Tregs and significantly higher number of inflammatory IFN-γ and IL-17-producing neutrophils, Th1 and Th17 cells were observed in the CDDP-injured kidneys of Gal-3^-/- mice. Pharmacological inhibitor of Gal-3 aggravated CDDP-induced AKI in WT animals while recombinant Gal-3 attenuated renal injury and inflammation in CDDP-treated Gal-3^-/- mice. CDDP-induced apoptosis, driven by Bax and caspase-3, was aggravated in Gal-3^-/- animals and in WT mice that received Gal-3 inhibitor (CDDP+Davanat-treated mice). Recombinant Gal-3 managed to completely attenuate CDDP-induced apoptosis in CDDP-injured kidneys of Gal-3^-/- mice. Genetic deletion as well as pharmacological inhibition of Gal-3 in renal DCs remarkably reduced TLR-2-dependent activation of IDO1/KYN pathway in these cells diminishing their capacity to prevent transdifferentiation of Tregs in inflammatory Th1 and Th17 cells. Additionally, Tregs generated by Gal-3 deficient DCs were not able to suppress production of IFN-γ and IL-17 in activated neutrophils. TLR-2-primed DCs significantly enhanced capacity of Tregs for attenuation of CDDP-induced AKI and inflammation and expression of Gal-3 on TLR-2-primed DCs was crucially important for their capacity to enhance nephroprotective and immunosuppressive properties of Tregs. Adoptive transfer of TLR-2-primed WTDCs significantly expanded Tregs in the kidneys of CDDP-treated WT and Gal-3^-/- recipients resulting in the suppression of IFN-γ and IL-17-driven inflammation and alleviation of AKI. Importantly, this phenomenon was not observed in CDDP-treated WT and Gal-3^-/- recipients of TLR-2-primed Gal-3^-/-DCs. Gal-3-dependent nephroprotective and immunosuppressive effects of renal DCs was due to the IDO1-induced expansion of renal Tregs since either inhibition of IDO1 activity in TLR-2-primed DCs or depletion of Tregs completely diminished DCs-mediated attenuation of CDDP-induced AKI. Conclusions: Gal-3 protects from CDDP-induced AKI by promoting TLR-2-dependent activation of IDO1/KYN pathway in renal DCs resulting in increased expansion of immunosuppressive Tregs in injured kidneys. Activation of Gal-3:TLR-2:IDO1 pathway in renal DCs should be further explored as new therapeutic approach for DC-based immunosuppression of inflammatory renal diseases.

Association between high Gal-3 serum levels and worsening of renal function in chronic heart failure outpatients

Aim: The aim of the study was to evaluate the association between Gal-3 serum levels and the progression of renal dysfunction in chronic heart failure outpatients. Methods & results: This prospective study of 260 chronic heart failure patients showed that Gal-3 was associated with 1-year worsening of renal function both in univariate (odds ratio: 1.12; 95% CI: 1.06-1.18; p < 0.001) and in forward stepwise multivariate (odds ratio: 1.09; 95% CI: 1.03-1.15; p = 0.004) logistic regression analyses. Moreover, high Gal-3 levels at baseline were associated with a progressive decline in the estimated glomerular filtration rate. Conclusion: Gal-3 is a biomarker associated with the progression of renal function decline thus further supporting its possible usefulness in predicting cardiorenal syndrome progression.

Blood and urine biomarkers in chronic kidney disease: An update

INTRODUCTION

Chronic kidney disease (CKD) is a silent disease. Most CKD patients are unaware of their condition during the early stages of the disease which poses a challenge for healthcare professionals to institute treatment or start prevention. The trouble with the diagnosis of CKD is that in most parts of the world, it is still diagnosed based on measurements of serum creatinine and corresponding calculations of eGFR. There are controversies with the current staging system, especially in the methodology to diagnose and prognosticate CKD.

OBJECTIVE

The aim of this review is to examine studies that focused on the different types of samples which may serve as a good and promising biomarker for early diagnosis of CKD or to detect rapidly declining renal function among CKD patient.

METHOD

The review of international literature was made on paper and electronic databases Nature, PubMed, Springer Link and Science Direct. The Scopus index was used to verify the scientific relevance of the papers. Publications were selected based on the inclusion and exclusion criteria.

RESULT

63 publications were found to be compatible with the study objectives. Several biomarkers of interest with different sample types were taken for comparison.

CONCLUSION

Biomarkers from urine samples yield more significant outcome as compare to biomarkers from blood samples. But, validation and confirmation with a different type of study designed on a larger population is needed. More comparison studies on different types of samples are needed to further illuminate which biomarker is the better tool for the diagnosis and prognosis of CKD.