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

A Systematic Review and Meta-Analysis of the Diagnostic Value of Galectin-3 in Acute Coronary Syndrome

Background/Objectives: We investigated the potential diagnostic role of galectin-3 (Gal-3) in patients presenting with suspected acute coronary syndromes (ACS). Methods: We searched PubMed Central, Scopus, EMBASE, and the Cochrane Library from inception until 20 June 2024. We measured effect sizes using odds ratios (OR) with 95% CIs for dichotomous data and mean differences (MD) with CIs for continuous data. Random synthesis analysis was performed if I2 was less than 50% or Q test p values were less than 0.05. Otherwise, a fixed pooled meta-analysis was performed. Results: The meta-analysis includes 15 eligible studies. Gal-3 levels were substantially higher in the ACS group (12.84 ± 8.48 ng/mL) compared to the control group (7.23 ± 6.05 ng/mL; MD = 3.89; 95% CI: 2.83 to 4.95; p < 0.001). Gal-3 levels in acute myocardial infarction (AMI) and control groups differed (10.09 ± 8.16 vs. 4.64 ± 3.07 ng/mL, MD = 4.30; 95% CI: 0.41 to 8.18; p < 0.001). Statistical analysis revealed significant differences in Gal-3 levels between ST-elevated myocardial infarction (STEMI) and control groups (10.62 ± 7.34 vs. 5.54 ± 2.96 ng/mL; MD = 5.54; 95% CI: 3.12 to 7.97; p < 0.001). No significant differences were found between the non-ST-elevated myocardial infarction (NSTEMI) vs. control groups or patients with STEMI vs. patients with NSTEMI. Conclusions: Gal-3 may be beneficial for detecting acute coronary syndromes but not NSTEMI or differentiating between ACS types. This meta-analysis is promising, but further research is needed to prove Gal-3's potential diagnostic value, exact cut-offs, and advantages over cardiospecific troponins. Gal-3 may be a useful diagnostic biomarker; however, more clinical trials are needed to prove its utility.

Novel targets and therapies of metformin in dementia: old drug, new insights

Dementia is a devastating disorder characterized by progressive and persistent cognitive decline, imposing a heavy public health burden on the individual and society. Despite numerous efforts by researchers in the field of dementia, pharmacological treatments are limited to relieving symptoms and fail to prevent disease progression. Therefore, studies exploring novel therapeutics or repurposing classical drugs indicated for other diseases are urgently needed. Metformin, a first-line antihyperglycemic drug used to treat type 2 diabetes, has been shown to be beneficial in neurodegenerative diseases including dementia. This review discusses and evaluates the neuroprotective role of metformin in dementia, from the perspective of basic and clinical studies. Mechanistically, metformin has been shown to improve insulin resistance, reduce neuronal apoptosis, and decrease oxidative stress and neuroinflammation in the brain. Collectively, the current data presented here support the future potential of metformin as a potential therapeutic strategy for dementia. This study also inspires a new field for future translational studies and clinical research to discover novel therapeutic targets for dementia.

Fibroblasts' secretome from calcified and non-calcified dermis in Pseudoxanthoma elasticum differently contributes to elastin calcification

Pseudoxanthoma elasticum (PXE) is a rare disease characterized by ectopic calcification, however, despite the widely spread effect of pro/anti-calcifying systemic factors associated with this genetic metabolic condition, it is not known why elastic fibers in the same patient are mainly fragmented or highly mineralized in clinically unaffected (CUS) and affected (CAS) skin, respectively. Cellular morphology and secretome are investigated in vitro in CUS and CAS fibroblasts. Here we show that, compared to CUS, CAS fibroblasts exhibit: a) differently distributed and organized focal adhesions and stress fibers; b) modified cell-matrix interactions (i.e., collagen gel retraction); c) imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinases; d) differentially expressed pro- and anti-calcifying proteoglycans and elastic-fibers associated glycoproteins. These data emphasize that in the development of pathologic mineral deposition fibroblasts play an active role altering the stability of elastic fibers and of the extracellular matrix milieu creating a local microenvironment guiding the level of matrix remodeling at an extent that may lead to degradation (in CUS) or to degradation and calcification (in CAS) of the elastic component. In conclusion, this study contributes to a better understanding of the mechanisms of the mineral deposition that can be also associated with several inherited or age-related diseases (e.g., diabetes, atherosclerosis, chronic kidney diseases).

Pectin: Health-promoting properties as a natural galectin-3 inhibitor

Galectin-3 has a variety of important pathophysiological significance in the human body. Much evidence shows that the abnormal expression of galectin-3 is related to the formation and development of many diseases. Pectin is mostly obtained from processed citrus fruits and apples and is a known natural inhibitor of galactin-3. A large number of peels produced each year are discarded, and it is necessary to recycle some of the economically valuable active compounds in these by-products to reduce resource waste and environmental pollution. By binding with galectin-3, pectin can directly reduce the expression level of galectin-3 on the one hand, and regulate the expression level of cytokines by regulating certain signaling pathways on the other hand, to achieve the effect of treating diseases. This paper begins by presenting an overview of the basic structure of pectin, subsequently followed by a description of the structure of galectin-3 and its detrimental impact on human health when expressed abnormally. The health effects of pectin as a galectin-3 inhibitor were then summarized from the perspectives of anticancer, anti-inflammatory, ameliorating fibrotic diseases, and anti-diabetes. Finally, the challenges and prospects of future research on pectin are presented, which provide important references for expanding the application of pectin in the pharmaceutical industry or developing functional dietary supplements.

Separation of high-purity plasma extracellular vesicles for investigating proteomic signatures in diabetic retinopathy

Extracellular vesicles (EVs) play a multifaceted role in intercellular communication and hold significant promise as bio-functional indicators for clinical diagnosis. Although plasma samples represent one of the most critical sources of circulating EVs, the existing technical challenges associated with plasma-EV isolation have restricted their application in disease diagnosis and biomarker discovery. In this study, we introduce a two-step purification method utilizing ultracentrifugation (UC) to isolate crude extracellular vesicle (EV) samples, followed by a phospholipid affinity-based technique for the selective isolation of small EVs, ensuring a high level of purity for downstream proteomic analysis. Our research demonstrates that the UC & TiO2-coated magnetic bead (TiMB) purification system significantly improves the purity of EVs when compared to conventional UC or TiMB along. We further revealed that proteomic alterations in plasma EVs effectively reflect key gene ontology components associated with diabetic retinopathy (DR) pathogenesis, including the VEGF-activated neuropilin pathway, positive regulation of angiogenesis, angiogenesis, cellular response to vascular endothelial growth factor stimulus, and immune response. By employing a comprehensive analytical approach, which incorporates both time-series analysis (cluster analysis) and differential analysis, we have identified three potential protein signatures including LGALS3, MYH10, and CPB2 that closely associated with the retinopathy process. These proteins exhibit promising diagnostic and severity-classification capabilities for DR disease. This adaptable EV isolation system can be regarded as an effective analytical tool for enhancing plasma-based liquid biopsies toward clinical applications.

Galectin-3 and Severity of Liver Fibrosis in Metabolic Dysfunction-Associated Fatty Liver Disease

Metabolic dysfunction-associated Fatty Liver Disease (MAFLD) is a chronic liver disease characterized by the accumulation of fat in the liver and hepatic steatosis, which can progress to critical conditions, including Metabolic dysfunction-associated Steatohepatitis (MASH), liver fibrosis, hepatic cirrhosis, and hepatocellular carcinoma. Galectin-3, a member of the galectin family of proteins, has been involved in cascades that are responsible for the pathogenesis and progression of liver fibrosis in MAFLD. This review summarizes the present understanding of the role of galectin-3 in the severity of MAFLD and its associated liver fibrosis. The article assesses the underlying role of galectin-3-mediated fibrogenesis, including the triggering of hepatic stellate cells, the regulation of extracellular degradation, and the modulation of immune reactions and responses. It also highlights the assessments of the potential diagnostic and therapeutic implications of galectin-3 in liver fibrosis during MAFLD. Overall, this review provides insights into the multifaceted interaction between galectin-3 and liver fibrosis in MAFLD, which could lead to the development of novel strategies for diagnosis and treatment of this prevalent liver disease.

Association between serum Galectin-3 and periodontitis in patients with type 2 diabetes mellitus

OBJECTIVES

This study aims to investigate the correlation between serum Galectin-3 levels and the risk of periodontitis in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 140 patients with T2DM admitted to the endocrinology department of Weifang People's Hospital, Affiliated to Weifang Medical College from July 2021 to November 2022 were selected and divided into T2DM without periodontitis group (T2DM group, n=67) and T2DM with periodontitis group (T2DMP group, n=73) according to whether they were combined with periodontitis. In the same period, 65 non-periodontitis volunteers with normal blood glucose were selected as healthy control group (NC group). Blood samples of all subjects were collected, and serum Galectin-3 levels and related laboratory indices were detected and compared among the three groups.

RESULTS

Serum Galectin-3 levels in the NC, T2DM, and T2DMP groups were 3.81 (3.49, 4.15), 4.82 (4.25, 5.26), and 6.83 (5.19, 7.28) ng/mL, respectively. After adjusting for the influence of baseline data by multiple linear regression, serum Galectin-3 levels in the T2DMP and T2DM groups were significantly higher than those in the NC group (all P<0.05). Multiple linear regression analysis showed that serum Galectin-3 levels were positively correlated with homeostatic model of the insulin resistance index (β=0.254, 95%CI:0.089-0.419, P=0.003), glycosylated hemoglobin A1c (β=0.397, 95%CI: 0.049-0.745, P=0.026), and clinical attachment loss (β=0.298, 95%CI: 0.024-0.572, P=0.033). After adjusting for the effects of covariates, binary logistic regression showed that serum Galectin-3 levels were significantly associated with the risk of periodontitis in patients with T2DM (OR=2.146, 95%CI: 1.260-3.655, P=0.005). Trend test showed that the risk of periodontitis in patients with T2DM increased with increasing serum Galectin-3 levels (Ptrend=0.011). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of serum Galectin-3 in predicting T2DM periodontitis was 0.861 (95%CI: 0.801-0.920, Z=11.806, P<0.001).

CONCLUSIONS

Serum Galectin-3 levels were elevated in patients with T2DM and pe-riodontitis and associated with the risk of periodontitis.

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.

Elevated galectin-3 levels detected in women with hyperglycemia during early and mid-pregnancy antagonizes high glucose - induced trophoblast cells apoptosis via galectin-3/foxc1 pathway

OBJECTIVE

This study was to evaluate plasma galectin-3 levels from early pregnancy to delivery and explore the effects of galectin-3 on the function of trophoblast cells under high glucose exposure.

METHODS

The plasma galectin-3 levels were quantified by enzyme-linked immunosorbent assay (ELISA) in the China National Birth Cohort (CNBC) at Peking University First Hospital, and the underlying signaling pathway was identified by protein-protein interaction (PPI) analysis, gene set enrichment analysis (GSEA), quantitative PCR (qPCR), western blotting, small interfering RNA (siRNA) transfections, and flow cytometry.

RESULTS

Significantly higher galectin-3 levels were found in patients with gestational diabetes mellitus (GDM group; n = 77) during the first and second trimesters than that in healthy pregnant women (HP group; n = 113) (P < 0.05). No significant differences in plasma galectin-3 levels were detected between GDM and HP groups in maternal third-trimester blood and cord blood. PPI analysis suggested potential interactions between galectin-3 and foxc1. The findings of GSEA showed that galectin-3 was involved in the cytochrome P450-related and complement-related pathways, and foxc1 was associated with type I diabetes mellitus. Additionally, high glucose (25 mM) significantly increased the expression levels of galectin-3 and foxc1 and induced apoptosis in HTR-8/SVneo cells. Further in vitro experiments showed that galectin-3/foxc1 pathway could protect HTR-8/SVneo cells against high glucose - induced apoptosis.

CONCLUSION

Future studies were required to validate whether plasma galectin-3 might become a potential biomarker for hyperglycemia during pregnancy. Elevated galectin-3 levels might be a vital protective mechanism among those exposed to hyperglycemia during pregnancy.

Inhibition of Galectins and the P2X7 Purinergic Receptor as a Therapeutic Approach in the Neurovascular Inflammation of Diabetic Retinopathy

Diabetic retinopathy (DR) is the most frequent microvascular retinal complication of diabetic patients, contributing to loss of vision. Recently, retinal neuroinflammation and neurodegeneration have emerged as key players in DR progression, and therefore, this review examines the neuroinflammatory molecular basis of DR. We focus on four important aspects of retinal neuroinflammation: (i) the exacerbation of endoplasmic reticulum (ER) stress; (ii) the activation of the NLRP3 inflammasome; (iii) the role of galectins; and (iv) the activation of purinergic 2X7 receptor (P2X7R). Moreover, this review proposes the selective inhibition of galectins and the P2X7R as a potential pharmacological approach to prevent the progression of DR.

The Pivotal Role of Galectin-3 in Viral Infection: A Multifaceted Player in Host-Pathogen Interactions

Galectin-3 (Gal-3), a beta-galactoside-binding lectin, plays a pivotal role in various cellular processes, including immune responses, inflammation, and cancer progression. This comprehensive review aims to elucidate the multifaceted functions of Gal-3, starting with its crucial involvement in viral entry through facilitating viral attachment and catalyzing internalization. Furthermore, Gal-3 assumes significant roles in modulating immune responses, encompassing the activation and recruitment of immune cells, regulation of immune signaling pathways, and orchestration of cellular processes such as apoptosis and autophagy. The impact of Gal-3 extends to the viral life cycle, encompassing critical phases such as replication, assembly, and release. Notably, Gal-3 also contributes to viral pathogenesis, demonstrating involvement in tissue damage, inflammation, and viral persistence and latency elements. A detailed examination of specific viral diseases, including SARS-CoV-2, HIV, and influenza A, underscores the intricate role of Gal-3 in modulating immune responses and facilitating viral adherence and entry. Moreover, the potential of Gal-3 as a biomarker for disease severity, particularly in COVID-19, is considered. Gaining further insight into the mechanisms and roles of Gal-3 in these infections could pave the way for the development of innovative treatment and prevention options for a wide range of viral diseases.

Positive Association of Serum Galectin-3 with the Development of Aortic Stiffness of Patients on Peritoneal Dialysis

A novel cardiovascular stress biomarker known as galectin-3 might be useful for anticipating adverse cardiovascular outcomes. The objective of the current investigation was to assess the association between serum galectin-3 levels and aortic stiffness (AS) in 196 patients on peritoneal dialysis. An enzyme-linked immunosorbent examination and a cuff-based volumetric displacement were employed to determine the levels of serum galectin-3 and the carotid-femoral pulse wave velocity (cfPWV), respectively. The AS group had 48 patients in total (24.5%) with cfPWV greater than 10 m/s. The AS group, when compared with the group without AS, had a significantly higher prevalence of diabetes mellitus and hypertension in addition to greater fasting glucose levels, waist circumference, systolic blood pressure, and serum galectin-3 levels. Multivariate logistic and linear regression analysis demonstrated that serum glactin-3 levels, in addition to gender and age, were significantly and independently associated with cfPWV and AS. Serum galectin-3 levels were linked with AS, according to a receiver operating characteristic curve analysis, with an area under the curve of 0.648 (95% confidence interval, 0.576-0.714; p = 0.0018). In summary, there was a significant correlation between serum galectin-3 levels and cfPWV in patients undergoing peritoneal dialysis therapy for end-stage kidney disease.

Fecal and Urinary Adipokines as Disease Biomarkers

The use of biomarkers is of great clinical value for the diagnosis and prognosis of disease and the assessment of treatment efficacy. In this context, adipokines secreted from adipose tissue are of interest, as their elevated circulating levels are associated with a range of metabolic dysfunctions, inflammation, renal and hepatic diseases and cancers. In addition to serum, adipokines can also be detected in the urine and feces, and current experimental evidence on the analysis of fecal and urinary adipokine levels points to their potential as disease biomarkers. This includes increased urinary adiponectin, lipocalin-2, leptin and interleukin-6 (IL-6) levels in renal diseases and an association of elevated urinary chemerin as well as urinary and fecal lipocalin-2 levels with active inflammatory bowel diseases. Urinary IL-6 levels are also upregulated in rheumatoid arthritis and may become an early marker for kidney transplant rejection, while fecal IL-6 levels are increased in decompensated liver cirrhosis and acute gastroenteritis. In addition, galectin-3 levels in urine and stool may emerge as a biomarker for several cancers. With the analysis of urine and feces from patients being cost-efficient and non-invasive, the identification and utilization of adipokine levels as urinary and fecal biomarkers could become a great advantage for disease diagnosis and predicting treatment outcomes. This review article highlights data on the abundance of selected adipokines in urine and feces, underscoring their potential to serve as diagnostic and prognostic biomarkers.

Modeling SILAC Data to Assess Protein Turnover in a Cellular Model of Diabetic Nephropathy

Protein turnover rate is finely regulated through intracellular mechanisms and signals that are still incompletely understood but that are essential for the correct function of cellular processes. Indeed, a dysfunctional proteostasis often impacts the cell's ability to remove unfolded, misfolded, degraded, non-functional, or damaged proteins. Thus, altered cellular mechanisms controlling protein turnover impinge on the pathophysiology of many diseases, making the study of protein synthesis and degradation rates an important step for a more comprehensive understanding of these pathologies. In this manuscript, we describe the application of a dynamic-SILAC approach to study the turnover rate and the abundance of proteins in a cellular model of diabetic nephropathy. We estimated protein half-lives and relative abundance for thousands of proteins, several of which are characterized by either an altered turnover rate or altered abundance between diabetic nephropathic subjects and diabetic controls. Many of these proteins were previously shown to be related to diabetic complications and represent therefore, possible biomarkers or therapeutic targets. Beside the aspects strictly related to the pathological condition, our data also represent a consistent compendium of protein half-lives in human fibroblasts and a rich source of important information related to basic cell biology.

The Blessed Union of Glycobiology and Immunology: A Marriage That Worked

In this article, we discuss the main aspects regarding the recognition of cell surface glycoconjugates and the immunomodulation of responses against the progression of certain pathologies, such as cancer and infectious diseases. In the first part, we talk about different aspects of glycoconjugates and delve deeper into the importance of N-glycans in cancer immunotherapy. Then, we describe two important lectin families that have been very well studied in the last 20 years. Examples include the sialic acid-binding immunoglobulin (Ig)-like lectins (siglecs), and galectins. Finally, we discuss a topic that needs to be better addressed in the field of glycoimmunology: the impact of oncofetal antigens on the cells of the immune system. New findings in this area are of great importance for advancement, especially in the field of oncology, since it is already known that cellular interactions mediated by carbohydrate-carbohydrate and/or carbohydrate proteins are able to modulate the progression of different types of cancer in events that compromise the functionality of the immune responses.

Advanced Glycation End Products and Inflammation in Type 1 Diabetes Development

Type 1 diabetes (T1D) is an autoimmune disease in which the β-cells of the pancreas are attacked by the host's immune system, ultimately resulting in hyperglycemia. It is a complex multifactorial disease postulated to result from a combination of genetic and environmental factors. In parallel with increasing prevalence of T1D in genetically stable populations, highlighting an environmental component, consumption of advanced glycation end products (AGEs) commonly found in in Western diets has increased significantly over the past decades. AGEs can bind to cell surface receptors including the receptor for advanced glycation end products (RAGE). RAGE has proinflammatory roles including in host-pathogen defense, thereby influencing immune cell behavior and can activate and cause proliferation of immune cells such as islet infiltrating CD8+ and CD4+ T cells and suppress the activity of T regulatory cells, contributing to β-cell injury and hyperglycemia. Insights from studies of individuals at risk of T1D have demonstrated that progression to symptomatic onset and diagnosis can vary, ranging from months to years, providing a window of opportunity for prevention strategies. Interaction between AGEs and RAGE is believed to be a major environmental risk factor for T1D and targeting the AGE-RAGE axis may act as a potential therapeutic strategy for T1D prevention.