Galectin-3 is independently associated with progression of nephropathy in type 2 diabetes mellitus

Integrated magneto-plasmonic nanostructures-based immunoassay for galectin-3 detection

Cardiovascular diseases remain a leading cause of global mortality, highlighting the need for accurate diagnostic tools and the detection of specific cardiac biomarkers. Surface-enhanced Raman scattering (SERS) spectroscopy has proved to be a promising alternative diagnostic tool to detect relevant biomarkers compared to traditional methods. To our knowledge, SERS methodology has never been used to detect galectin-3 (Gal-3), a crucial biomarker for cardiovascular conditions. Our study aimed to develop plasmonic and magneto-plasmonic nanoplatforms for the sensitive immunodetection of Gal-3 using SERS. Spherical gold nanoparticles (AuNPs) were synthesized and functionalized with 11-mercaptoundecanoic acid (MUDA) to enable antibody binding and 4-mercaptobenzoic acid (4MBA) that served as a Raman reporter due to its intense Raman signal. Following bioconjugation with Gal-3 antibody, the AuNPs were employed in the immunodetection of Gal-3 in phosphate-buffer saline (PBS) solution, offering a limit of detection (LOD) of 12.2 ng mL-1 and a working range up to 120 ng mL-1. Furthermore, our SERS-based immunosystem demonstrated selectivity for Gal-3 (40 ng mL-1) in the presence of other biomolecules such as α-amylase, bovine serum albumin and human C-reactive protein. As a proof of concept, we developed magneto-plasmonic nanoparticles composed of silica-coated magnetite decorated with the bioconjugated AuNPs aimed at enhancing the uptake and detection of Gal-3 via SERS coupled with Raman imaging. Our findings underscore the potential of SERS-based techniques for the sensitive and specific detection of biomarkers, holding significant implications for improved diagnosis and surveillance of cardiovascular diseases. Future research will focus on further optimizing these nanoplatforms and their translation into clinical settings.

Association of serum galectin-3 levels with mortality and cardiovascular disease outcomes in hemodialysis patients: a systematic review and dose-response meta-analysis

BACKGROUND

Galectin-3 has been proposed as a candidate marker for cardiovascular risk stratification, although its role in kidney failure is unclear. The aim of this systematic review was to assess the association of serum galectin-3 levels with overall survival and cardiovascular outcomes among hemodialysis patients.

METHODS

Medline, Scopus, Web of Science and CENTRAL were systematically searched from inception till Aug 20, 2023. Observational studies evaluating the association of serum galectin-3 with mortality, cardiovascular disease and arterial stiffness in hemodialysis patients were included. The exposure-response relationship between galectin-3 and mortality was explored by dose-response meta-analysis using restricted cubic splines in a one-stage approach.

RESULTS

Overall, 13 studies were included (9 cohort and 4 cross-sectional), comprising 6025 hemodialysis individuals. Increasing galectin-3 values were associated with greater all-cause mortality risk (χ2: 18.71, p-value < 0.001) and an insignificant trend toward higher cardiovascular mortality risk (χ2: 5.06, p-value: 0.079). Compared to a reference galectin-3 value of 10 ng/ml, all-cause mortality risk was significantly higher with levels of 20 ng/ml (Hazard ratio-HR: 2.62, 95% confidence intervals-CI: 1.66-4.15), 30 ng/ml (HR: 3.78, 95% CI: 2.05-6.97) and 40 ng/ml (HR: 4.01, 95% CI: 2.14-7.52). Qualitative synthesis of evidence indicated that serum galectin-3 may be linked to abdominal aortic calcification severity and progression, as well as to left ventricular systolic and diastolic dysfunction.

CONCLUSIONS

This study suggests that high serum galectin-3 levels are associated with greater all-cause mortality risk among patients on maintenance hemodialysis. Preliminary cross-sectional evidence indicates that serum galectin-3 may be associated with arterial stiffness and left ventricular dysfunction.

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.

Galectin-3 in chronic kidney disease

BACKGROUND AND AIMS

High serum galectin-3 has been associated with adverse outcomes among dialysis patients, although its prognostic role remains unclear among individuals with earlier-stage chronic kidney disease. The present systematic review aims to evaluate the association of serum galectin-3 with survival, cardiovascular disease and kidney disease progression among non-dialysis chronic kidney disease patients.

METHODS

PubMed, Scopus, Web of Science, CENTRAL and Google Scholar were systematically searched till November 10, 2023. All observational studies assessing the prognostic role of serum galectin-3 in patients with non-dialysis chronic kidney disease were included.

RESULTS

Overall, 12 studies (10 cohort, 2 cross-sectional) were included, comprising 9,349 patients. The endpoint of survival was assessed in 5 studies, indicating a significant association between increasing serum galectin-3 levels and higher all-cause mortality risk (Hazard ratio per unit: 1.22, 95 % confidence intervals-CI: 1.05-1.41, ≥6 ng/mL: 2.66, 95 % CI: 1.68-4.23). Current evidence coming from 4 studies was inconclusive regarding the potential link of galectin-3 and kidney function decline, yielding conflicting results. No significant associations between serum galectin-3 and heart failure, cardiovascular events or death were consistently reported.

CONCLUSIONS

This systematic review supports the prognostic role of galectin-3 in chronic kidney disease, as its increased serum values may be associated with higher all-cause mortality risk. No clear role could be supported for serum galectin-3 regarding the prediction of cardiovascular disease or kidney disease progression.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Time-course analysis of liver and serum galectin-3 in acute liver injury after alpha-galactosylceramide injection

Galectin-3 is a beta-galactoside-binding lectin that plays important roles in diverse physiological functions, such as cell proliferation, apoptosis, and mRNA splicing. This protein is expressed on inflammatory cells and acts as a local inflammatory mediator. Recently, galectin-3 has been detected in several diseases, such as chronic liver, heart, and kidney diseases, diabetes, viral infection, autoimmune and neurodegenerative diseases, and tumors, and its role as a biomarker has attracted attention. Alpha-galactosylceramide is an artificially synthesized sphingolipid that can induce acute liver injury via the natural killer T pathway. However, the pathophysiological roles and kinetics of galectin-3 in acute liver injury are not fully understood. This study aimed to elucidate the expression and time course of galectin-3 in liver tissues during acute liver injury following alpha-galactosylceramide injection. Animals were histologically examined on days 1, 2, 4, and 7 after intraperitoneal injection of alpha-galactosylceramide, and the expressions of galectin-3 and ionized calcium-binding adaptor molecule 1 were analyzed. Notably, galectin-3 formed characteristic cluster foci, particularly on day 2 after injection. Cluster formation was not observed in chronic liver disease. Simultaneously, ionized calcium-binding adaptor molecule 1-positive cells were observed in the cluster foci. Serum galectin-3 levels increased on day 2 of treatment and correlated well with the number of galectin-3-positive cell clusters in the liver. Moreover, galectin-3 expression was an important mediator of the early phase of liver injury after alpha-galactosylceramide injection. These results suggest that serum galectin-3 may be a biomarker for the early diagnosis of acute liver injury and that clusters of galectin-3-positive cells may be a specific finding in acute liver injury.

High blood galectin-3 level associated with risk of frailty in aging

Background

Frailty is one of the most problematic expressions of population aging, but its underlying mechanism has not been fully elucidated. Circulating galectin-3 (Gal-3) is involved in the pathogenesis of many age-related diseases. This study aims to explore the influence of circulating Gal-3 on the regulation of frailty and aging and to identify the potential mechanism further.

Methods

In this cross-sectional analysis, the Fried frailty phenotype (FP) was assessed among 149 community elderly residents in Shanghai. Peripheral blood mononuclear cells (PBMCs) were isolated by the Ficoll-Paque density gradient method, and differentially expressed genes (DEGs) encoding transcription factors in frailty were detected by Illumina and bioinformatics analyzed with R software. Gene Ontology (GO) enrichment analyses and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to explore the functional roles of these DEGs and the target genes related to frailty phenotypes. The serum Gal-3 concentration was tested by enzyme-linked immunosorbent assay (ELISA). Mouse frailty phenotype was used to construct an in vivo model of frailty, after which the serum levels of circulating Gal-3 and its gene expression levels in mouse tissues were determined.

Results

Participants' mean age was 72.04 ± 7.05 years. In total, 21.48% were frail and 36.91% were pre-frail. The mean serum Gal-3 concentration was 46.34 ± 17.99 ng/mL in frail participants, 32.30 ± 8.14 ng/mL in pre-frail participants, and 26.00 ± 5.87 ng/mL in non-frail individuals (p < 0.001). Significant positive correlations between serum Gal-3 level and FP score, SARC-F score, C-reactive protein (CRP), interleukin-6, etc., were observed. In addition, the KEGG pathway and GO enrichment analyses showed that 265 DEGs in PBMCs of frail participants were mainly related to inflammatory response, translation, RNA binding, protein binding, ribosome, and primary immunodeficiency. LGALS3 was identified as the overlapping gene between frailty-related DEGs and aging-related DEGs. The elevated serum Gal-3 concentration in the in vivo model of frailty was consistent with the results in participants.

Conclusion

In both community-dwelling older adults and aged mice, serum Gal-3 concentration was positively correlated with frailty. This circulating mediator may be a promising indicator of frailty.

Clinical trial registration

Chinese Clinical Trial Registry identifier, ChiCTR2000036399.

The Role of Galectin-3 in Heart Failure-The Diagnostic, Prognostic and Therapeutic Potential-Where Do We Stand?

Heart failure (HF) is a clinical syndrome with high morbidity and mortality, and its prevalence is rapidly increasing. Galectin-3 (Gal-3) is an important factor in the pathophysiology of HF, mainly due to its role in cardiac fibrosis, inflammation, and ventricular remodeling. Fibrosis is a hallmark of cardiac remodeling, HF, and atrial fibrillation development. This review aims to explore the involvement of Gal-3 in HF and its role in the pathogenesis and clinical diagnostic and prognostic significance. We report data on Gal-3 structure and molecular mechanisms of biological function crucial for HF development. Over the last decade, numerous studies have shown an association between echocardiographic and CMR biomarkers in HF and Gal-3 serum concentration. We discuss facts and concerns about Gal-3's utility in acute and chronic HF with preserved and reduced ejection fraction for diagnosis, prognosis, and risk stratification. Finally, we present attempts to use Gal-3 as a therapeutic target in HF.

The Role of Galectin-3 in Predicting Congenital Heart Disease Outcome: A Review of the Literature

Galectin-3 (Gal-3) is a novel pro-fibrotic biomarker that can predict both right and left cardiac dysfunction caused by various cardiovascular conditions. Its expression seems to be progressively altered with evolving cardiac remodeling processes, even before the onset of heart failure. Hence, Gal-3 has been found to be an individual predictor of acute and chronic heart failure or to serve as part of an integrated biomarker panel that can foresee adverse cardiac outcomes. In congenital heart disease (CHD), Gal-3 correlates with cardiac mortality and complications in both children and adults and is proposed as a therapeutic target in order to reverse the activation of pro-fibrosis pathways that lead to heart failure. Positive associations between serum Gal-3 levels, post-operatory hospitalization rates, complications and ventricular dysfunction have also been reported within studies conducted on patients with CHD who underwent corrective surgery. Thus, this review tried to address the potential utility of Gal-3 in patients with CHD and particularly in those who undergo corrective surgery. The heterogeneity of the literature data and the lack of validation of the results obtained by the current studies on larger cohorts cannot be neglected, though. Further longitudinal research is required to establish how Gal-3 can relate to long-term outcomes in pediatric CHD.

Circulating Galectin-3 levels and Diabetic Nephropathy: a systematic review and meta-analysis

AIMS

Changes of serum galectin-3 (Gal-3) is associated with the pathogenesis of diabetic nephropathy (DN). However, current literature indicates that the given results remain debatable and inconsistent. Hence, the aim of this present meta-analysis was to focus on the predictive role of serum Gal-3 in patients with DN.

METHODS

The PubMed, Embase, Cochrane Library and Web of Science databases were systematically searched for studies that reported the relationship between Gal-3 levels and DN risk, from the inception of each database to March, 2023. The literature we selected for inclusion based on inclusion and exclusion criteria. The standard mean difference (SMD) with corresponding 95% confidence intervals (95% CI) were used to investigate the association. When I2 value exceeding 50%, we will consider it has the presence of a higher level of heterogeneity. A sensitivity analysis and subgroup analysis were performed to seek the potential sources of heterogeneity. The quality assessment was performed using according to the Newcastle-Ottawa Quality Assessment Scale (NOS). The data analysis was conducted using STATA version 13.0 software.

RESULTS

We ultimately enrolled 9 studies enrolling a total of 3137 patients in the final analysis. The SMD of serum Gal-3 was higher in patients with DN group (SMD 1.10 ng/mL [0.63, 1.57]; I2: 96.1%). Upon removal of a study in sensitivity analysis, patients with DN had higher serum Gal-3 levels compared to control patients (SMD 1.03 ng/mL [0.52, 1.54], I2: 94.4%). Further subgroup analysis was performed based on the region. No matter in Asia, Europe or Africa, the serum Gal-3 level of DN patients is significantly higher than that of the control population (SMD: 0.73; 95% CI: 0.58 to 0.87 for Asian; SMD: 0.79; 95% CI: 0.48 to 1.10 for Europe; SMD: 3.15; 95% CI: 2.73 to 3.56 for Africa).

CONCLUSION

In conclusion, these results suggested that higher serum Gal-3 may increase the risk of DN. More fundamental studies are necessary to clarify the exact physiopathological basis mechanisms of Gal-3 effects. In addition, further research, especially emphasis on the cut-off value should be given, and is best to predict their actual importance as well as the diagnostic accuracy.

Precision Medicine and/or Biomarker Based Therapy in T2DM: Ready for Prime Time?

Approximately 30-40% of people with type 2 diabetes mellitus develop chronic kidney disease. This is characterised by elevated blood pressure, declining kidney function and enhanced cardiovascular morbidity and mortality. Increased albuminuria and decreasing estimated glomerular function has to be evaluated regularly to diagsnose kidney disease. New biomarkers may facilitate early diagnosis and provide infomation on undlying pathology thereby supporting early precision intervention for the optimal benefit. A number of biomarkers have been suggested but are not yet implemented in clinical practice. iI the future such bimarkers may pave the way for personalized treatment.

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.

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.

Galectin-3 as a Potential Prognostic Biomarker for COVID-19 Disease: A Case-Control Study

Background

Recent studies have investigated the importance of Galetin-3 in inflammation, fibrosis, cell proliferation, cardiac disease, diabetes, and tumor formation.

Aims

This study aims to investigate the role of the Galectin-3 level in the diagnosis of COVID-19 pneumonia and the value of the Galectin-3 level in predicting the clinical course of the patient.

Methods

This study employed a prospective, case-control study design and was conducted at Bakircay University Ciğli Training and Research Hospital. A total of 100 patients (40 had moderate and 60 had severe/critical COVID-19 disease according to World Health Organisation guidelines) and 50 non-symptomatic healthy volunteers participated in the study. Blood samples were taken from patients at the time of hospital admission, after which serum was isolated. Following the isolation of serum, Galectin-3 levels were evaluated using the enzyme-linked immunosorbent assay (ELISA) method. 

Results

The serum Galectin-3 level was measured as 13.57 (10.9-16.4) ng/mL in the control group, 13.52 (10.69-16.6) ng/mL in the moderate disease group, and 11.65 (6.09-14.33) ng/mL in the severe/critical disease group. Serum Galectin-3 levels were significantly lower in the severe/critical disease group compared to the control and moderate disease groups (p=0.001 and p=0.019, respectively).

Using ROC analysis, a larger area under the curve (AUC) for the serum Galectin-3 levels of the control group (AUC=0.622, 95% CI =0.529-0.714; p=0.015) was calculated compared to the COVID-19 patient group for the diagnosis of COVID-19 disease. The Galectin-3 level was found to be 75% sensitive and 50% specific at a cut-off level of 11.3 ng/mL in predicting the need for ICU treatment.

Conclusion

Galectin-3 levels may be a beneficial biomarker in predicting the clinical severity of COVID-19 disease when used in conjunction with other known biomarkers, at the time of admission to the emergency department (ED).

Galectin-3 as a Potential Biomarker of Microvascular Complications in Patients with Type 2 Diabetes

Introduction

Human Galectin-3 is a 32- to 35-kDa size lectin, mainly comprises a C-terminal carbohydrate recognition binding domain (CRD) and N-terminal domain. It acts as a powerful pro-inflammatory signalling factor, which plays an important role in the activation, chemotaxis, and cytokine release of inflammatory cells. Galectin-3 has also been studied in relation to development of insulin resistance. The levels of galectin-3 have been observed to be associated with both diabetes prevalence and incidence, independent of traditional diabetes risk factors. It is also associated with development of microvascular complications of diabetes mellitus like retinopathy, nephropathy and neuropathy.

Methods

Tertiary care hospital-based cross-sectional prospective study. 150 patients selected by simple random sampling and were divided into 3 groups., Group A - Patients of Type 2 Diabetes mellitus without microvascular complications (n=50), Group B - patients of Type 2 diabetes mellitus with microvascular complications (n=50) and Group C - Healthy control (n=50).

Statistical Analysis

Descriptive statistics was performed by calculating mean and standard deviation for the continuous variables. chi-square goodness-to-fit test, Student T test (unpaired) and Analysis of variance (ANOVA) and multivariate analysis were used to compare means. The p-value was taken significant when less than 0.05 (P<0.05) and a confidence interval of 95%.

Results

In group A, B and C majority of patients were between 56-60 years with 34%, 40% and 36% cases, respectively. The mean BMI shows that the Patients with complications had significantly higher BMI than those without complications and controls had significantly lower BMI than patients having diabetes. The data shows statistical significance with deranged biochemical profile in patients with DM with complications as compared to patients without complications and control group. In both groups A and B patients with HbA1c between 9.1-12 had mean serum galectin level (20.2 in group A, 25.9 in group B) significantly higher than patients with HbA1c between 6.5-9 (18.5 in group A and 20.4 in group B). patients with deranged lipid profile had significantly higher serum galectin level in all 3 groups, with cases from group B having higher values than group A. While controls had the lowest value of serum galectin (P value<0.001). There was a highly significant correlation between high serum galectin levels and the incidence of both non-progressive and progressive retinopathy (P value=0.0001). The mean galectin of patients with neuropathy was 28.3 ± 3.1 ng/ml, which was significantly higher than patients from group B without neuropathy (24.5 ± 2.6 ng/ml). The mean serum galectin level of patients with macroalbuminuria was 30.1± 1.3 ng/ml which was significantly higher than those with microalbuminuria having mean galectin level of 22.8 ±4.8 ng/ml. There was a highly significant correlation between high serum galectin levels and the incidence of both micro and macroalbuminuria (P value=0.0001).

Conclusion

This study concludes that elevated serum Galectin-3 levels are associated with diabetes-related chronic inflammatory processing pathway, and closely relates to the severity of diabetes in T2DM both with and without complications. Therefore, Galectin-3 may be helpful in the diagnosis and prognosis of microvascular and macrovascular complications in T2DM patients.

Nonsteroidal Mineralocorticoid Receptor Antagonism by Finerenone—Translational Aspects and Clinical Perspectives across Multiple Organ Systems

Perception of the role of the aldosterone/mineralocorticoid receptor (MR) ensemble has been extended from a previously renal epithelial-centered focus on sodium and volume homeostasis to an understanding of their role as systemic modulators of reactive oxygen species, inflammation, and fibrosis. Steroidal MR antagonists (MRAs) are included in treatment paradigms for resistant hypertension and heart failure with reduced ejection fraction, while more recently, the nonsteroidal MRA finerenone was shown to reduce renal and cardiovascular outcomes in two large phase III trials (FIDELIO-DKD and FIGARO-DKD) in patients with chronic kidney disease and type 2 diabetes, respectively. Here, we provide an overview of the pathophysiologic role of MR overactivation and preclinical evidence with the nonsteroidal MRA finerenone in a range of different disease models with respect to major components of the aggregate mode of action, including interfering with reactive oxygen species generation, inflammation, fibrosis, and hypertrophy. We describe a time-dependent effect of these mechanistic components and the potential modification of major clinical parameters, as well as the impact on clinical renal and cardiovascular outcomes as observed in FIDELIO-DKD and FIGARO-DKD. Finally, we provide an outlook on potential future clinical indications and ongoing clinical studies with finerenone, including a combination study with a sodium–glucose cotransporter-2 inhibitor.

Molecular Mechanisms and Therapeutic Targets for Diabetic Kidney Disease

Diabetic kidney disease has a high global disease burden and substantially increases risk of kidney failure and cardiovascular events. Despite treatment, there is substantial residual risk of disease progression with existing therapies. Therefore, there is an urgent need to better understand the molecular mechanisms driving diabetic kidney disease to help identify new therapies that slow progression and reduce associated risks. Diabetic kidney disease is initiated by diabetes-related disturbances in glucose metabolism, which then trigger other metabolic, hemodynamic, inflammatory, and fibrotic processes that contribute to disease progression. This review summarizes existing evidence on the molecular drivers of diabetic kidney disease onset and progression, focusing on inflammatory and fibrotic mediators-factors that are largely unaddressed as primary treatment targets and for which there is increasing evidence supporting key roles in the pathophysiology of diabetic kidney disease. Results from recent clinical trials highlight promising new drug therapies, as well as a role for dietary strategies, in treating diabetic kidney disease.

The impact of zinc supplementation on galectin-3 and metabolic markers in diabetic patients on hemodialysis: A randomized, double-blind, placebo-controlled trial

Purpose

There is little information about the association between zinc sulfate (ZnSO4) supplementation and metabolic profiles in zinc-deficient diabetic patients on hemodialysis (DHPs). Therefore, we aimed to investigate the association between ZnSO4 supplementation and serum levels of galectin-3 (Gal-3) and cardiometabolic parameters in zinc-deficient DHPs.

Methods

In the present randomized double-blind placebo-controlled clinical trial, 46 zinc-deficient DHPs (35-62 years) were included and assigned to receive either 220 mg/d ZnSO4 or placebo for 8 weeks. Serum levels of Gal-3, lipid profile, and blood pressure (BP) were assessed at baseline and the end of trial.

Results

We found a significant effect of ZnSO4 intake on the reduction of serum Gal-3 (P =  < 0.001), triglycerides (P =  < 0.001), total cholesterol (P =  < 0.001), low-density lipoprotein cholesterol (P =  < 0.001) and increased high-density lipoprotein cholesterol (P =  < 0.001) as compared to the control group. Additionally, systolic blood pressure (SBP) (P = 0.006) and diastolic blood pressure (DBP) (P = 0.01) were significantly reduced following 8 weeks of ZnSO4 supplementation.

Conclusion

Taken together, 220 mg ZnSO4 supplementation per day for 8 weeks among zinc-deficient DHPs had beneficial effects on Gal-3 and metabolic profiles.

Iranian Registry of Clinical Trials Identifier

IRCT20191217045765N1, date of registration: 2020-02-09.

Emerging roles of Galectin-3 in diabetes and diabetes complications: A snapshot

Galectin-3 is a member of the galectin family, widely expressed in immune cells and plays a role mainly in inflammation, autoimmunity, apoptosis, and chemotaxis. We summarized the roles of Galectin-3 in diabetes and its complications, as well as the underlying mechanisms. Clinical research has determined that the circulating level of Galectin-3 is closely related to diabetes and its complications, thus it is promising to use Galectin-3 as a predictor and biomarker for those diseases. Galectin-3 also may be considered as an ideal therapeutic target, which has broad prospects in the prevention and treatment of diabetes and its complications, especially macrovascular and microvascular complications.

Cardiovascular Biomarkers: Lessons of the Past and Prospects for the Future

Cardiovascular diseases (CVDs) are a major healthcare burden on the population worldwide. Early detection of this disease is important in prevention and treatment to minimise morbidity and mortality. Biomarkers are a critical tool to either diagnose, screen, or provide prognostic information for pathological conditions. This review discusses the historical cardiac biomarkers used to detect these conditions, discussing their application and their limitations. Identification of new biomarkers have since replaced these and are now in use in routine clinical practice, but still do not detect all disease. Future cardiac biomarkers are showing promise in early studies, but further studies are required to show their value in improving detection of CVD above the current biomarkers. Additionally, the analytical platforms that would allow them to be adopted in healthcare are yet to be established. There is also the need to identify whether these biomarkers can be used for diagnostic, prognostic, or screening purposes, which will impact their implementation in routine clinical practice.

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.

Improving the residual risk of renal and cardiovascular outcomes in diabetic kidney disease: A review of pathophysiology, mechanisms, and evidence from recent trials

Based on global estimates, almost 10% of adults have diabetes, of whom 40% are estimated to also have chronic kidney disease (CKD). Almost 2 decades ago, treatments targeting the renin-angiotensin system (RAS) were shown to slow the progression of kidney disease. More recently, studies have reported the additive benefits of antihyperglycaemic sodium-glucose co-transporter-2 inhibitors in combination with RAS inhibitors on both CKD progression and cardiovascular outcomes. However, these recent data also showed that patients continue to progress to kidney failure or die from kidney- or cardiovascular-related causes. Therefore, new agents are needed to address this continuing risk. Overactivation of the mineralocorticoid (MR) receptor contributes to kidney inflammation and fibrosis, suggesting that it is an appropriate treatment target in patients with diabetes and CKD. Novel, selective non-steroidal MR antagonists are being studied in these patients, and the results of two large recently completed clinical trials have shown that one such treatment, finerenone, significantly reduces CKD progression and cardiovascular events compared with standard of care. This review summarizes the pathogenic mechanisms of CKD in type 2 diabetes and examines the potential benefit of novel disease-modifying agents that target inflammatory and fibrotic factors in these patients.

Establishment of Galectin-3 Time-resolved Fluoroimmunoassay and its Application in Idiopathic Membranous Nephropathy

The aim of this study was to establish a time-resolved fluorescent immunoassay (TRFIA) for the detection of serum Galectin-3 (Gal-3) and apply this method to evaluate the clinical significance of serum Gal-3 in predicting Idiopathic Membranous Nephropathy (IMN) progression. The Gal-3-TRFIA was established using the double antibody sandwich method, with the capture antibodies coated on a 96-well microplate and the detection antibodies chelated with Europium (III) (Eu³⁺). Serum Gal-3 was detected in 81 patients with IMN and 123 healthy controls to further evaluate the value of the Gal-3 in staging of IMN. The sensitivity of the Gal-3-TRFIA assay was 0.85 ng/mL, and the detection range was 0.85-1000 ng/mL. The Gal-3 intra-batch and inter-batch coefficients of variation were 3.45% and 5.12%, respectively. The correlation coefficient (R) between the Gal-3-TRFIA assay and commercially available enzyme-linked immunosorbent assay kits was 0.83. The serum Gal-3 concentration was higher in patients with IMN (65.57 ± 55.90 ng/mL) compared to healthy controls (16.29 ± 9.91 ng/mL, P < 0.0001). In this study, a wide detection range Gal-3-TRFIA assay was developed using lanthanide (Eu³⁺) chelates for the detection of Gal-3 concentrations in serum. Gal-3 concentration is elevated in patients with IMN.

The Diagnostic and Therapeutic Potential of Galectin-3 in Cardiovascular Diseases

Galectin-3 plays a prominent role in chronic inflammation and has been implicated in the development of many disease conditions, including heart disease. Galectin-3, a regulatory protein, is elevated in both acute and chronic heart failure and is involved in the inflammatory pathway after injury leading to myocardial tissue remodelling. We discussed the potential utility of galectin-3 as a diagnostic and disease severity/prognostic biomarker in different cardio/cerebrovascular diseases, such as acute ischemic stroke, acute coronary syndromes, heart failure and arrhythmogenic cardiomyopathy. Over the last decade there has been a marked increase in the understanding the role of galectin-3 in myocardial fibrosis and inflammation and as a therapeutic target for the treatment of heart failure and myocardial infarction.

Endothelial ADAM17 Expression in the Progression of Kidney Injury in an Obese Mouse Model of Pre-Diabetes

Disintegrin and metalloproteinase domain 17 (ADAM17) activates inflammatory and fibrotic processes through the shedding of various molecules such as Tumor Necrosis Factor-α (TNF-α) or Transforming Growht Factor-α (TGF-α). There is a well-recognised link between TNF-α, obesity, inflammation, and diabetes. In physiological situations, ADAM17 is expressed mainly in the distal tubular cell while, in renal damage, its expression increases throughout the kidney including the endothelium. The aim of this study was to characterize, for the first time, an experimental mouse model fed a high-fat diet (HFD) with a specific deletion of Adam17 in endothelial cells and to analyse the effects on different renal structures. Endothelial Adam17 knockout male mice and their controls were fed a high-fat diet, to induce obesity, or standard rodent chow, for 22 weeks. Glucose tolerance, urinary albumin-to-creatinine ratio, renal histology, macrophage infiltration, and galectin-3 levels were evaluated. Results showed that obese mice presented higher blood glucose levels, dysregulated glucose homeostasis, and higher body weight compared to control mice. In addition, obese wild-type mice presented an increased albumin-to-creatinine ratio; greater glomerular size and mesangial matrix expansion; and tubular fibrosis with increased galectin-3 expression. Adam17 deletion decreased the albumin-to-creatinine ratio, glomerular mesangial index, and tubular galectin-3 expression. Moreover, macrophage infiltration in the glomeruli of obese Adam17 knockout mice was reduced as compared to obese wild-type mice. In conclusion, the expression of ADAM17 in endothelial cells impacted renal inflammation, modulating the renal function and histology in an obese pre-diabetic mouse model.

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.

Mineralocorticoid Receptor Pathway and Its Antagonism in a Model of Diabetic Retinopathy

Diabetic retinopathy remains a major cause of vision loss worldwide. Mineralocorticoid receptor (MR) pathway activation contributes to diabetic nephropathy, but its role in retinopathy is unknown. In this study, we show that MR is overexpressed in the retina of type 2 diabetic Goto-Kakizaki (GK) rats and humans and that cortisol is the MR ligand in human eyes. Lipocalin 2 and galectin 3, two biomarkers of diabetes complications regulated by MR, are increased in GK and human retina. The sustained intraocular delivery of spironolactone, a steroidal mineralocorticoid antagonist, decreased the early and late pathogenic features of retinopathy in GK rats, such as retinal inflammation, vascular leakage, and retinal edema, through the upregulation of genes encoding proteins known to intervene in vascular permeability such as Hey1, Vldlr, Pten, Slc7a1, Tjp1, Dlg1, and Sesn2 but did not decrease VEGF. Spironolactone also normalized the distribution of ion and water channels in macroglial cells. These results indicate that MR is activated in GK and human diabetic retina and that local MR antagonism could be a novel therapeutic option for diabetic retinopathy.

Galectins in Cancer and the Microenvironment: Functional Roles, Therapeutic Developments, and Perspectives

Changes in cell growth and metabolism are affected by the surrounding environmental factors to adapt to the cell’s most appropriate growth model. However, abnormal cell metabolism is correlated with the occurrence of many diseases and is accompanied by changes in galectin (Gal) performance. Gals were found to be some of the master regulators of cell–cell interactions that reconstruct the microenvironment, and disordered expression of Gals is associated with multiple human metabolic-related diseases including cancer development. Cancer cells can interact with surrounding cells through Gals to create more suitable conditions that promote cancer cell aggressiveness. In this review, we organize the current understanding of Gals in a systematic way to dissect Gals’ effect on human disease, including how Gals’ dysregulated expression affects the tumor microenvironment’s metabolism and elucidating the mechanisms involved in Gal-mediated diseases. This information may shed light on a more precise understanding of how Gals regulate cell biology and facilitate the development of more effective therapeutic strategies for cancer treatment by targeting the Gal family.

Role of novel biomarkers in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is commonly defined as cardiomyopathy in patients with diabetes mellitus in the absence of coronary artery disease and hypertension. As DCM is now recognized as a cause of substantial morbidity and mortality among patients with diabetes mellitus and clinical diagnosis is still inappropriate, various expert groups struggled to identify a suitable biomarker that will help in the recognition and management of DCM, with little success so far. Hence, we thought it important to address the role of biomarkers that have shown potential in either human or animal studies and which could eventually result in mitigating the poor outcomes of DCM. Among the array of biomarkers we thoroughly analyzed, long noncoding ribonucleic acids, soluble form of suppression of tumorigenicity 2 and galectin-3 seem to be most beneficial for DCM detection, as their plasma/serum levels accurately correlate with the early stages of DCM. The combination of relatively inexpensive and accurate speckle tracking echocardiography with some of the highlighted biomarkers may be a promising screening method for newly diagnosed diabetes mellitus type 2 patients. The purpose of the screening test would be to direct affected patients to more specific confirmation tests. This perspective is in concordance with current guidelines that accentuate the importance of an interdisciplinary team-based approach.

Galectin-3/adiponectin as a new biological indicator for assessing the risk of type 2 diabetes: a cross-sectional study in a community population

OBJECTIVE

This study aimed to explore the association between the risk of newly diagnosed type 2 diabetes and galectin-3 and adiponectin and to investigate whether their joint action shows a favorable diabetes assessment performance.

METHODS

We conducted a community-based study in 135 newly diagnosed patients with type 2 diabetes and 270 age- and sex-matched nondiabetic patients. Odds ratios and 95% confidence intervals were determined using logistic regression analysis. Receiver operating characteristic curve, decision curve analysis and calibration plot were used to explore their efficacy and clinical utility for models.

RESULTS

High quartiles of galectin-3/adiponectin (quartile 4 vs 1: OR 2.43 [95% CIs: 1.21-5.00]) showed the strongest correlation with an increased risk of type 2 diabetes in the total population, which was consistent in the older population (age≥50 years old) in adjustment models. The combination + lipids + galectin-3/adiponectin model (AUC = 0.72 [95% CIs: 0.66-0.77]) displayed better diabetes assessment performance than the other two models.

CONCLUSIONS

High galectin-3 and low adiponectin levels were associated with the high risk of diabetes, and their joint action was a superior promising factor for evaluating diabetes risk. The diabetes discriminative strength of galectin-3/adiponectin was better in the older population than the younger.

Heart Failure and Diabetes Mellitus: Biomarkers in Risk Stratification and Prognostication

Heart failure (HF) and type 2 diabetes mellitus (T2DM) have a synergistic effect on cardiovascular (CV) morbidity and mortality in patients with established CV disease (CVD). The aim of this review is to summarize the knowledge regarding the discriminative abilities of conventional and novel biomarkers in T2DM patients with established HF or at higher risk of developing HF. While conventional biomarkers, such as natriuretic peptides and high-sensitivity troponins demonstrate high predictive ability in HF with reduced ejection fraction (HFrEF), this is not the case for HF with preserved ejection fraction (HFpEF). HFpEF is a heterogeneous disease with a high variability of CVD and conventional risk factors including T2DM, hypertension, renal disease, older age, and female sex; therefore, the extrapolation of predictive abilities of traditional biomarkers on this population is constrained. New biomarker-based approaches are disputed to be sufficient for improving risk stratification and the prediction of poor clinical outcomes in patients with HFpEF. Novel biomarkers of biomechanical stress, fibrosis, inflammation, oxidative stress, and collagen turn-over have shown potential benefits in determining prognosis in T2DM patients with HF regardless of natriuretic peptides, but their role in point-to-care and in routine practice requires elucidation in large clinical trials.

Galectin-3 in T cell-mediated immunopathology and autoimmunity

Galectin-3 (Gal-3) is the only member of galectin family able to form pentamers and heterodimers with chemokines. Its presence in various cells and tissues suggests variety of regulatory functions in physiological conditions, but increasing body of evidence indicates involvement of Gal-3 in pathological cascades of many diseases. Gal-3 exerts different, sometimes opposite, effects in various disorders or in different phases of the same disease. These differences in action of Gal-3 are related to the localization of Gal-3 in the cell, types of receptors through which it acts, or the types of cells that secrete it. As a regulator of immune response and T-cell activity, Gal-3 appears to have important role in development of autoimmunity mediated by T cells. Absence of Gal-3 in C57Bl6 mice favors Th2 mediated inflammatory myocarditis but attenuate fibrosis. Recent data also indicate Gal-3 involvement in development atherosclerosis. In pathogenesis of diabetes type 1 and autoimmune components of diabetes type 2 Gal-3 may have detrimental or protective role depending on its intracellular or extracellular localization. Gal-3 mediates autoimmune hepatic damage through activation of T-cells or natural killer T cells. Gal-3 is an important mediator in neurodevelopment, neuropathology and behavior due to its expression both in neurons and glial cells. All together, assessing the role of Gal-3 in immunopathology and autoimmunity it could be concluded that it is an important participant in pathogenesis, as well as promising monitoring marker and therapeutic target.

Insulin Receptor Substrate p53 Ameliorates High-Glucose-Induced Activation of NF-κB and Impaired Mobility of HUVECs

Diabetes-related macrovascular and microvascular complications lead to poor prognosis. Insulin receptor substrate p53 (IRSp53) is known to act as a substrate for the insulin receptor tyrosine kinase, but its role in endothelial dysfunction remains unclear. Human umbilical vein endothelial cells (HUVECs) treated with D-glucose at different concentrations and a streptozocin-induced rat diabetes mellitus (DM) model were used to investigate the effects of hyperglycemia on the expression levels of IRSp53 and galectin-3 (gal-3) and the inflammatory state and mobility of HUVECs. Thereafter, IRSp53-overexpressing HUVECs and IRSp53-knockdown HUVECs were established using IRSp53-overexpressing lentivirus or IRSp53-siRNA to explore the role of IRSp53 in the HUVEC inflammatory state and HUVEC mobility. D-glucose at high concentration (HG) and hyperglycemia were found to induce downregulation of IRSp53 and upregulation of gal-3 in vitro and in vivo. Treatment with HG resulted in activation of NF-κB in HUVECs and impaired HUVEC mobility. Insulin restored HG-induced changes in the expression levels of IRSp53 and gal-3 in HUVECs and protected the cells from NF-κB activation and impaired mobility. Overexpression of IRSp53 inhibited the activation of NF-κB in HUVECs and strengthened HUVEC migration. Knockdown of IRSp53 facilitated the activation of NF-κB in HUVECs and decreased HUVEC migration. However, neither overexpression nor knockdown of IRSp53 altered the effects of insulin on HG-induced detrimental changes in HUVECs. HG and hyperglycemia resulted in downregulation of IRSp53 in vitro and in vivo. IRSp53 is concluded to inhibit the activation of NF-κB in HUVECs and to strengthen HUVEC migration.

Galectin-3 mediates cardiac remodeling caused by impaired glucose and lipid metabolism through inhibiting two pathways of activating Akt

Pathological cardiac remodeling is a leading cause of mortality in patients with diabetes. Given the glucose and lipid metabolism disorders (GLDs) in patients with diabetes, it is urgent to conduct a comprehensive study of the myocardial damage under GLDs and find key mechanisms. Apolipoprotein E knockout (ApoE-/-) mice, low-density lipoprotein receptor heterozygote (Ldlr+/-) Syrian golden hamsters, or H9C2 cells were used to construct GLDs models. GLDs significantly promoted cardiomyocyte fibrosis, apoptosis, and hypertrophy in vivo and in vitro, but inhibition of galectin-3 (Gal-3) could significantly reverse this process. Then, the signal transmission pathways were determined. It was found that GLDs considerably inhibited the phosphorylation of Akt at Thr308/Ser473, whereas the silencing of Gal-3 could reverse the inhibition of Akt activity through phosphoinositide 3-kinase-AktThr308 (PI3K-AktThr308) and AMP-activated protein kinase-mammalian target of rapamycin complex 2-AktSer473 (AMPK-mTOR2-AktSer473) pathways. Finally, the PI3K, mTOR, AMPK inhibitor, and Akt activator were used to investigate the role of pathways in regulating cardiac remodeling. Phospho-AktThr308 could mediate myocardial fibrosis, whereas myocardial apoptosis and hypertrophy were regulated by both phospho-AktThr308 and phospho-AktSer473. In conclusion, Gal-3 was an important regulatory factor in GLDs-induced cardiac remodeling, and Gal-3 could suppress the phosphorylation of Akt at different sites in mediating cardiomyocyte fibrosis, apoptosis, and hypertrophy.NEW & NOTEWORTHY Studies on the pathogenesis of diabetic cardiac remodeling are highly desired. Glucose and lipid metabolism are both disordered in diabetes. Glucose and lipid metabolism disturbances promote myocardial fibrosis, apoptosis, and hypertrophy through galectin-3. Galectin-3 promotes cardiac remodeling by inhibiting phosphorylation of AktThr308 or AktSer473. The present study finds that glucose and lipid metabolism disorders are important causes for myocardial damage and provides novel ideas for the prevention and treatment of diabetic cardiac remodeling.

Research progress on the role of gal-3 in cardio/cerebrovascular diseases

Galectin-3 (gal-3), a member of the galectin family, is a glycoprotein with high affinity for β-galactoside. Gal-3 is a cytoplasmically synthesized protein that can shuttle between the cytoplasm and nucleus and can even be transported to the membrane and secreted into the extracellular environment. Cardio/cerebrovascular diseases generally refer to ischemic or hemorrhagic diseases occurring in the heart, brain and systemic tissues, which are characterized by high morbidity, high disability rates and high mortality rates. To date, considerable research has demonstrated that gal-3 expression is aberrantly increased and plays important roles in cardio/cerebrovascular diseases, such as acute ischemic stroke (AIS), myocardial fibrosis, acute coronary syndrome (ACS), and heart failure (HF). Hence, understanding the biological roles of gal-3 in these diseases may be essential for cardio/cerebrovascular disease treatment and diagnosis to improve patient quality of life. In this review, we summarize current research on the roles of gal-3 in human cardiovascular diseases and potential inhibitors of gal-3, which may provide new strategies for disease therapies.

The therapeutic potential of galectin-3 inhibition in fibrotic disease

Galectin-3 is a beta-galactoside-binding mammalian lectin and part of the 15 member galectin family that are evolutionarily highly conserved. It is the only chimeric protein with a C-terminal carbohydrate recognition domain (CRD) linked to a proline, glycine, and tyrosine rich additional N-terminal domain. Galectin-3 binds several cell surface glycoproteins via its CRD domain as well as undergoing oligomerization, via binding at the N-terminal or the CRD, resulting in the formation of a galectin-3 lattice on the cell surface. The galectin-3 lattice has been regarded as being a crucial mechanism whereby extracellular galectin-3 modulates cellular signalling by prolonging retention time or retarding lateral movement of cell surface receptors in the plasma membrane. As such galectin-3 can regulate various cellular functions such as diffusion, compartmentalization and endocytosis of plasma membrane glycoproteins and glycolipids and the functionality of membrane receptors. In multiple models of organ fibrosis, it has been demonstrated that galectin-3 is potently pro-fibrotic and modulates the activity of fibroblasts and macrophages in chronically inflamed organs. Increased galectin-3 expression also activates myofibroblasts resulting in scar formation and may therefore impact common fibrotic pathways leading to fibrosis in multiple organs. Over the last decade there has been a marked increase in the scientific literature investigating galectin-3 in a range of fibrotic diseases as well as the clinical development of new galectin-3 inhibitors. In this review we will examine the role of galectin-3 in fibrosis, the therapeutic strategies for inhibiting galectin-3 in fibrotic disease and the clinical landscape to date.

Galectin-3: A Potential Prognostic and Diagnostic Marker for Heart Disease and Detection of Early Stage Pathology

The use of molecular biomarkers for the early detection of heart disease, before their onset of symptoms, is an attractive novel approach. Ideal molecular biomarkers, those that are both sensitive and specific to heart disease, are likely to provide a much earlier diagnosis, thereby providing better treatment outcomes. Galectin-3 is expressed by various immune cells, including mast cells, histiocytes and macrophages, and plays an important role in diverse physiological functions. Since galectin-3 is readily expressed on the cell surface, and is readily secreted by injured and inflammatory cells, it has been suggested that cardiac galectin-3 could be a marker for cardiac disorders such as cardiac inflammation and fibrosis, depending on the specific pathogenesis. Thus, galectin-3 may be a novel candidate biomarker for the diagnosis, analysis and prognosis of various cardiac diseases, including heart failure. The goals of heart disease treatment are to prevent acute onset and to predict their occurrence by using the ideal molecular biomarkers. In this review, we discuss and summarize recent developments of galectin-3 as a next-generation molecular biomarker of heart disease. Furthermore, we describe how galectin-3 may be useful as a diagnostic marker for detecting the early stages of various heart diseases, which may contribute to improved early therapeutic interventions.

Prevalence of mild cognitive impairment in type 2 diabetes mellitus is associated with serum galectin-3 level

AIMS/INTRODUCTION

Galectin-3 (Gal3) contributes to insulin resistance, inflammation and obesity, the three risk factors for mild cognitive impairment (MCI) in type 2 diabetes mellitus patients.

MATERIALS AND METHODS

A total of 134 hospitalized type 2 diabetes mellitus patients were assessed by the Montreal Cognitive Assessment method, and divided into 65 MCI and 69 controls. Levels of variables, Gal3 and Aβ42, were investigated in relation with cognitive function in both type 2 diabetes mellitus patients with MCI and high-fat diet/streptozotocin induced type 2 diabetes mellitus rats.

RESULTS

Significantly higher levels of serum Gal3 and lower levels of plasma Aβ42 (all P < 0.05) were found in the MCI type 2 diabetes mellitus group as compared with the non-MCI type 2 diabetes mellitus control. Partial correlation analysis showed that Gal3 is negatively correlated with both MMSE score (r = -0.51, P < 0.01) and Montreal Cognitive Assessment score (r = -0.47, P < 0.001) after adjustment for glycated hemoglobin, homoeostasis model assessment of insulin resistance and Aβ42 in all type 2 diabetes mellitus patients, with a stronger effect seen in the MCI type 2 diabetes mellitus group after further analysis with MCI strata. A simple logistic regression model showed that Gal3 and Aβ42 are significantly associated with MCI type 2 diabetes mellitus patients after adjustment with the covariates sex, age, body mass index, glycated hemoglobin, homoeostasis model assessment of insulin resistance and antidiabetic drugs. Serum and brain Gal3 levels were significantly increased in high-fat diet/streptozotocin diabetic rats, which correlate to the impairment of learning and memory ability. Gal3 inhibitor modified citrus pectin decreased serum and brain Gal3 levels in diabetic rats, accompanied by the amelioration of learning and memory impairment.

CONCLUSIONS

Gal3 might be associated with cognitive impairment in type 2 diabetes mellitus, and serum Gal3 level might be a new risk factor of MCI in type 2 diabetes mellitus patients.

Circulating Cardiac Biomarkers in Diabetes Mellitus: A New Dawn for Risk Stratification-A Narrative Review

The aim of this narrative review is to update the current knowledge on the differential choice of circulating cardiac biomarkers in patients with prediabetes and established type 2 diabetes mellitus (T2DM). There are numerous circulating biomarkers with unconfirmed abilities to predict clinical outcomes in pre-DM and DM individuals; the prognostication ability of the cardiac biomarkers reported here has been established, and they are still being studied. The conventional cardiac biomarkers, such as natriuretic peptides (NPs), soluble suppressor tumorigenisity-2, high-sensitivity circulating cardiac troponins and galectin-3, were useful to ascertain cardiovascular (CV) risk. Each cardiac biomarker has its strengths and weaknesses that affect the price of usage, specificity, sensitivity, predictive value and superiority in face-to-face comparisons. Additionally, there have been confusing reports regarding their abilities to be predictably relevant among patients without known CV disease. The large spectrum of promising cardiac biomarkers (growth/differential factor-15, heart-type fatty acid-binding protein, cardiotrophin-1, carboxy-terminal telopeptide of collagen type 1, apelin and non-coding RNAs) is discussed in the context of predicting CV diseases and events in patients with known prediabetes and T2DM. Various reasons have been critically discussed related to the variable findings regarding biomarker-based prediction of CV risk among patients with metabolic disease. It was found that NPs and hs-cTnT are still the most important tools that have an affordable price as well as high sensitivity and specificity to predict clinical outcomes among patients with pre-DM and DM in routine clinical practice, but other circulating biomarkers need to be carefully investigated in large trials in the future.

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.

Galectin-3 mediates high-glucose-induced cardiomyocyte injury by the NADPH oxidase/reactive oxygen species pathway

Galectin-3 is a member of the β-galactoside-binding lectin family taking part in the regulation of inflammation, angiogenesis, and fibrosis. This study was designed to study the improved effect of galectin-3 inhibition on diabetic cardiomyopathy (DCM). Sprague-Dawley rats were randomized into the control, DCM, and DCM + modified citrus pectin (MCP) (a galectin-3 pharmacological inhibitor) groups. After 8 weeks, streptozotocin-induced DCM led to high blood glucose level, oxidative stress, cardiac injury, and dysfunction accompanied by suppressed body mass. On the contrary, MCP (100 mg·kg^-1·day^-1) administration improved body mass and blood glucose level and attenuated cardiac injury and dysfunction in DCM rats. Additionally, MCP attenuated pathological changes in plasma and myocardial tissue markers of oxidative stress, such as hydrogen peroxide and malonyldialdehyde, although it did not change superoxide dismutase activities, which were decreased in the DCM group. The levels of oxidative stress associated proteins evaluated by Western blot, such as p67^phox and NADPH oxidase 4, were obviously increased in the DCM group, while they were reversed by MCP treatment. Therefore, galectin-3-mediated high-glucose-induced cardiomyocyte injury and galectin-3 inhibition attenuated DCM by suppressing NADPH oxidase. These findings suggested that galectin-3 could be a potential target for treatment of patients with DCM.

Galectin-3 as a Next-Generation Biomarker for Detecting Early Stage of Various Diseases

Galectin-3 is a β-galactoside-binding lectin which is important in numerous biological activities in various organs, including cell proliferation, apoptotic regulation, inflammation, fibrosis, and host defense. Galectin-3 is predominantly located in the cytoplasm and expressed on the cell surface, and then often secreted into biological fluids, like serum and urine. It is also released from injured cells and inflammatory cells under various pathological conditions. Many studies have revealed that galectin-3 plays an important role as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease, viral infection, autoimmune disease, neurodegenerative disorders, and tumor formation. In particular, it has been recognized that galectin-3 is extremely useful for detecting many of these diseases in their early stages. The purpose of this article is to review and summarize the recent literature focusing on the biomarker characteristics and long-term outcome predictions of galectin-3, in not only patients with various types of diseases, but associated animal models.

Carbamylated Lipoproteins and Progression of Diabetic Kidney Disease

BACKGROUND AND OBJECTIVES

Protein carbamylation is a consequence of uremia and carbamylated lipoproteins contribute to atherogenesis in CKD. Proteins can also be carbamylated by a urea-independent mechanism, and whether carbamylated lipoproteins contribute to the progression of CKD has not been investigated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A case-control study was performed to determine whether there were changes in plasma levels of carbamylated lipoproteins in individuals with type 2 diabetes with eGFR >60 ml/min per 1.73 m² compared with a group of age- and sex-matched healthy controls. A cohort of 1320 patients with type 2 diabetes with baseline eGFR ≥30 ml/min per 1.73 m² was longitudinally followed up to evaluate the association between carbamylated lipoproteins and progression of CKD. The primary kidney outcome was defined as doubling of serum creatinine and/or initiation of KRT during follow-up. Plasma carbamylated LDLs and HDLs was measured by ELISA.

RESULTS

In individuals with diabetes with eGFR >60 ml/min per 1.73 m², both plasma carbamylated LDL and HDL levels were higher compared with healthy controls (P<0.001). After a mean follow-up of 9 years of the diabetic cohort, individuals in the top quartile of carbamylated LDL (hazard ratio, 2.21; 95% confidence interval, 1.42 to 3.46; P<0.001) and carbamylated HDL (hazard ratio, 4.53; 95% confidence interval, 2.87 to 7.13; P<0.001) had higher risk of deterioration of kidney function compared with those in the lowest quartile. On multivariable Cox regression analysis, plasma carbamylated LDL was no longer associated with kidney outcome after adjusting for baseline eGFR and potential confounding factors. However, the association between plasma carbamylated HDL and kidney outcome remained significant and was independent of HDL cholesterol.

CONCLUSIONS

Plasma carbamylated HDL but not carbamylated LDL was independently associated with progression of CKD in patients with type 2 diabetes.

Association of Galectin-3 With Diabetes Mellitus in the Dallas Heart Study

CONTEXT

Galectin-3 is a biomarker associated with inflammation and fibrosis in cardiac, liver, and renal disease. Galectin-3 is higher in overweight and obese individuals; whether an association with diabetes exists independent of weight is unknown.

OBJECTIVE

To evaluate if galectin-3 is associated with diabetes mellitus.

DESIGN

We performed measurements of galectin-3 among participants in the Dallas Heart Study (DHS) Phases 1 and 2 (DHS-1 and DHS-2; n = 3392, and n = 3194, respectively). Of these, 1989 participants were evaluated longitudinally in both studies. Associations of galectin-3 with prevalent and incident type 2 diabetes were determined using logistic regression models. Associations of galectin-3 with relevant biomarkers and fat compartments were evaluated using Spearman correlation coefficients and multivariable linear regression models, respectively.

SETTING AND PARTICIPANTS

DHS is a population-based, single-site, multiethnic study conducted in Dallas County, Texas, with oversampling to comprise 50% blacks.

RESULTS

Galectin-3 levels were associated with diabetes prevalence in DHS-1 [OR 1.56 per SD change in log-galectin (95% CI 1.41 to 1.73)] and DHS-2 [OR 1.86 (95% CI 1.67 to 2.06)]. Galectin-3 levels in DHS-1 also associated with incident diabetes mellitus over the 7.1 (interquartile range 6.6 to 7.6)-year follow-up period [OR 1.34 (95% CI 1.14 to 1.58)]. These associations maintained significance in models adjusted for traditional metabolic risk factors (age, sex, race, body mass index, and hypertension) and renal function. Galectin-3 levels correlated with levels of biomarkers implicated in inflammation (high-sensitivity C-reactive peptide, IL-18, monocyte chemoattractant protein 1, soluble TNF receptor 1A, myeloperoxidase), insulin secretion (C-peptide and C-peptide/homeostatic model assessment for insulin resistance), and subcutaneous adiposity.

CONCLUSIONS

Galectin-3 is associated with diabetes prevalence and incidence, possibly through the inflammatory pathway contributing to β-cell fibrosis and impaired insulin secretion.

Long non-coding RNA Rpph1 promotes inflammation and proliferation of mesangial cells in diabetic nephropathy via an interaction with Gal-3

Diabetic nephropathy (DN) is one of the most significant complications of diabetes and is the primary cause of end-stage kidney disease. Cumulating evidence has shown that renal inflammation plays a role in the development and progression of DN, but the exact cellular mechanisms are unclear. Irregular expression of long non-coding RNAs (lncRNAs) is present in many diseases, including DN. However, the relationship between lncRNAs and inflammation in DN is unclear. In this study, we identified differentially expressed lncRNAs in DN using RNA-sequencing. Among these lncRNAs, we identified seven DN-related lncRNAs in vivo and in vitro using quantitative real-time PCR. One lncRNA in particular, Rpph1 (ribonuclease P RNA component H1), exhibited significantly increased expression. Further, over-expression or knockdown of Rpph1 was found to regulate cell proliferation and the expression of inflammatory cytokines in mesangial cells (MCs). The results revealed that Rpph1 directly interacts with the DN-related factor galectin-3 (Gal-3). Further, over-expression of Rpph1 promoted inflammation and cell proliferation through the Gal-3/Mek/Erk signaling pathway in MCs under low glucose conditions, while knockdown of Rpph1 inhibited inflammation and cell proliferation through the Gal-3/Mek/Erk pathway in MCs under high glucose conditions. These results provide new insight into the association between Rpph1 and the Gal-3/Mek/Erk signaling pathway during DN progression.

Elevated Platelet Galectin-3 and Rho-Associated Protein Kinase Activity Are Associated with Hemodialysis Arteriovenous Shunt Dysfunction among Subjects with Diabetes Mellitus

Introduction

Hyperglycemia is a major factor in influencing the patency rate of arteriovenous shunts, potentially associated with the RhoA/Rho-associated protein kinase (ROCK) pathway. Besides, galectin-3 mediates thrombotic mechanisms in venous thrombosis and peripheral artery disease. We hypothesized that high ROCK activity and galectin-3 levels are associated with arteriovenous shunt dysfunction.

Methods

We prospectively enrolled 38 patients diagnosed with arteriovenous shunt dysfunction. 29 patients received a complete follow-up and each provided two blood samples, which were collected at the first visit for occluded status of arteriovenous shunts and 1 month later for patent status. A Western blot assay for a myosin phosphatase target subunit (MYPT) was performed to examine Rho-kinase activity. A Western blot assay for platelet galectin-3 and enzyme-linked immunosorbent assay (ELISA) for circulating galectin-3 were completed.

Results

Higher platelet MYPT ratios and galectin-3 levels were identified at occluded arteriovenous shunts (MYPT ratio: 0.5 [0.3-1.4] vs. 0.4 [0.3-0.6], p = 0.01; galectin-3: 1.2 [0.4-1.6] vs. 0.7 [0.1-1.2], p = 0.0004). The plasma galectin-3 binding protein ELISA was also higher at occluded arteriovenous shunts (8.4 [6.0-9.7] μg/mL vs. 7.1 [4.5-9.1] μg/mL, p = 0.009). Biomarker ratios (occluded/patent status) trended high in patients with poorly controlled diabetes (MYPT ratio: 1.7 [1.0-3.0] vs. 1.1 [0.7-1.3], p = 0.06; galectin-3: 1.6 [1.3-3.4] vs. 1.1 [0.8-1.9], p = 0.05).

Conclusion

High platelet ROCK activity and galectin-3 levels are associated with increased risk in arteriovenous shunt dysfunction, especially in patients with poorly controlled diabetes.