Role of Galectin-3 in Obesity and Impaired Glucose Homeostasis. Oxid Med Cell Longev. 2016;2016:9618092. [PMID: 26770660 PMCID: PMC4684889 DOI: 10.1155/2016/9618092]

Liraglutide improves adipose tissue remodeling and mitochondrial dynamics in a visceral obesity model induced by a high-fat diet

Central obesity is characterized by visceral adipose tissue (VAT) expansion, considered one of the main risk factors for metabolic complications. In recent years, new drugs have been studied for obesity treatment. Liraglutide (LGT), a GLP-1 agonist, decreases body weight, however, several mechanisms of action on VAT are still unknown.

Aim

to study the effect of LGT on factors associated with VAT remodeling and mitochondrial dynamics in mice fed a high-fat diet (HFD).

Methods

C57BL/6 mice were divided into Control (C) and HFD. After 15 weeks of feeding, each group was subdivided according to LGT administration for 5 weeks: C, C + LGT, HFD, and HFD + LGT. In epididymal AT (EAT) we evaluated histological and mitochondrial characteristics, vascularity, gelatinase activity (MMPs), and galectin-3 expression.

Results

HFD presented larger adipocytes (p < 0.05), and lower vascular density and MMP-9 activity (p < 0.01) than C, while a major number of smaller adipocytes (p < 0.05) and an increase in vascularity (p < 0.001) and MMP-9 activity (p < 0.01) was observed in HFD + LGT. Collagen content was higher (p < 0.05) in EAT from HFD and decreased in HFD + LGT. In C, C + LGT, and HFD + LGT, mitochondria were predominantly tubular-shaped while in HFD mitochondria were mostly spherical (p < 0.001).

Conclusion

LGT positively influences VAT behavior by modulating gelatinase activity, enhancing vascularization, and improving adipocyte histological characteristics. Additionally, LGT improves mitochondrial dynamics, a process that would favor VAT functionality.

Metabolic profiling of galectin-1 and galectin-3: a cross-sectional, multi-omics, association study

OBJECTIVES

Experimental studies indicate a role for galectin-1 and galectin-3 in metabolic disease, but clinical evidence from larger populations is limited.

METHODS

We measured circulating levels of galectin-1 and galectin-3 in the Prospective investigation of Obesity, Energy and Metabolism (POEM) study, participants (n = 502, all aged 50 years) and characterized the individual association profiles with metabolic markers, including clinical measures, metabolomics, adipose tissue distribution (Imiomics) and proteomics.

RESULTS

Galectin-1 and galectin-3 were associated with fatty acids, lipoproteins and triglycerides including lipid measurements in the metabolomics analysis adjusted for body mass index (BMI). Galectin-1 was associated with several measurements of adiposity, insulin secretion and insulin sensitivity, while galectin-3 was associated with triglyceride-glucose index (TyG) and fasting insulin levels. Both galectins were associated with inflammatory pathways and fatty acid binding protein (FABP)4 and -5-regulated triglyceride metabolic pathways. Galectin-1 was also associated with several proteins related to adipose tissue differentiation.

CONCLUSIONS

The association profiles for galectin-1 and galectin-3 indicate overlapping metabolic effects in humans, while the distinctly different associations seen with fat mass, fat distribution, and adipose tissue differentiation markers may suggest a functional role of galectin-1 in obesity.

Impaired Remodeling of White Adipose Tissue in Obesity and Aging: From Defective Adipogenesis to Adipose Organ Dysfunction

The adipose organ adapts and responds to internal and environmental stimuli by remodeling both its cellular and extracellular components. Under conditions of energy surplus, the subcutaneous white adipose tissue (WAT) is capable of expanding through the enlargement of existing adipocytes (hypertrophy), followed by de novo adipogenesis (hyperplasia), which is impaired in hypertrophic obesity. However, an impaired hyperplastic response may result from various defects in adipogenesis, leading to different WAT features and metabolic consequences, as discussed here by reviewing the results of the studies in animal models with either overexpression or knockdown of the main molecular regulators of the two steps of the adipogenesis process. Moreover, impaired WAT remodeling with aging has been associated with various age-related conditions and reduced lifespan expectancy. Here, we delve into the latest advancements in comprehending the molecular and cellular processes underlying age-related changes in WAT function, their involvement in common aging pathologies, and their potential as therapeutic targets to influence both the health of elderly people and longevity. Overall, this review aims to encourage research on the mechanisms of WAT maladaptation common to conditions of both excessive and insufficient fat tissue. The goal is to devise adipocyte-targeted therapies that are effective against both obesity- and age-related disorders.

Galectin-3, Metabolic Risk, and Incident Heart Failure: The ARIC Study

BACKGROUND

It is unclear how metabolic syndrome (MetS) and diabetes affect Gal-3 (galectin 3) levels and the resulting implications for heart failure (HF) risk. We assessed relationships of MetS and diabetes with Gal-3, and their joint associations with incident HF.

METHODS AND RESULTS

We included 8445 participants without HF (mean age, 63 years; 59% men; 16% Black race) at ARIC (Atherosclerosis Risk in Communities) study visit 4 (1996-1999). We categorized participants as having MetS only, MetS with diabetes, or neither, and by quartiles of MetS severity Z score. We assessed cross-sectional associations of metabolic risk categories with high Gal-3 level (≥75th percentile) using logistic regression. We used Cox regression to evaluate combined associations of metabolic risk categories and Gal-3 quartiles with HF. In cross-sectional analyses, compared with no MetS and no diabetes, MetS only (odds ratio [OR], 1.24 [95% CI, 1.10-1.41]) and MetS with diabetes (OR, 1.59 [95% CI, 1.32-1.92]) were associated with elevated Gal-3. Over a median follow-up of 20.5 years, there were 1749 HF events. Compared with individuals with neither diabetes nor MetS and with Gal-3 in the lowest quartile, the combination of MetS with diabetes and Gal-3 ≥75th percentile was associated with a 4-fold higher HF risk (hazard ratio, 4.35 [95% CI, 3.30-5.73]). Gal-3 provided HF prognostic information above and beyond MetS, NT-proBNP (N-terminal pro-B-type natriuretic peptide), high-sensitivity cardiac troponin T, and CRP (C-reactive protein) (ΔC statistic for models with versus without Gal-3: 0.003; P=0.004).

CONCLUSIONS

MetS and diabetes are associated with elevated Gal-3. The HF risk significantly increased with the combination of greater metabolic risk and higher Gal-3.

Circulating Galectin-3 levels in women with polycystic ovary syndrome: A meta-analysis

Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine disorder characterized by multifactorial and intricate pathogenesis. The discovery of novel markers has been a significant step toward understanding the mechanisms of PCOS. Galectin-3 has emerged as a novel factor in metabolic disorders. This meta-analysis examines the association between circulating Galectin-3 and PCOS. A systematic review and meta-analysis were performed to identify relevant articles in the electronic databases PubMed, Web of Science, Scopus, Cochrane, EMBASE, and Google Scholar. The search covered the period from January 2000 to March 2023 and followed a predefined search strategy. Eight articles were included in the analysis with a total of 594 participants (322 patients with PCOS and 272 controls). Pooled standardized mean difference (SMD) and 95 % confidence interval [CI] were used to evaluate the association between Galectin-3 levels and PCOS. The results indicated a significant association between PCOS and galectin-3 levels (SMD = 0.58; 95 % CI: 0.15-1.01; p = 0.007). In addition, subgroup analysis showed a significant difference in serum Galectin-3 levels in women with PCOS and a higher homeostatic model assessment for insulin resistance ratio (SMD = 0.89; 95 % CI: 0.45-1.33; p < 0.001). The researchers also performed meta-regression and subgroup analyses to specify sources of heterogeneity. The results of our meta-analysis suggest an association between increased levels of galectin-3 and PCOS. Galectin-3 plays a significant role in the progression of PCOS and could be used as a novel diagnostic biomarker. Nevertheless, it is essential to perform further studies to confirm and support our conclusions.

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.

Role of galectin-3 as a biomarker in obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Because obstructive sleep apnea (OSA) is a prevalent condition, biomarkers for OSA would be very useful. Galectin-3 has gained attention as a marker for several diseases. The aim of this study was to investigate the association between circulating galectin-3 levels and OSA.

METHODS

PubMed, Scopus, Embase, and Web of Science were explored to find the studies evaluating galectin-3 in OSA and controls, within different severities of OSA, or before and after continuous positive airway pressure (CPAP) treatment in cases with OSA. We used random-effect meta-analysis to calculate standardized mean differences (SMD) along with 95% confidence intervals (CI). Newcastle-Ottawa Scale was used assessment of the risk of bias in studies.

RESULTS

An initial search resulted in 289 results. After exclusion of duplicate studies, screening of titles/abstracts and assessments of full texts, six studies were included comprised of 987 cases with a mean age of 54.4 years. Meta-analysis showed that there were significantly higher galectin-3 circulating levels in patients with OSA than in healthy controls (SMD 0.80, 95% CI 0.30 to 1.31, p value < 0.01). Severe OSA was related to higher levels of galectin-3, in comparison to non-severe OSA (SMD 0.76, 95% CI 0.29 to 1.22, p value < 0.01). CPAP therapy also significantly reduced galectin-3 peripheral levels in patients with OSA (SMD - 3.55, 95% CI - 6.90 to - 0.20, p value = 0.04).

CONCLUSION

The findings suggest that Galectin-3 may have potential utility as a biomarker in patients with OSA. Further research is needed to demonstrate its role in pathophysiology, as well as its possible use in diagnosis and prognosis.

TNF-α promotes CXCL-1/8 production in keratinocytes by downregulating galectin-3 through NF-κB and hsa-miR-27a-3p pathway to contribute psoriasis development

OBJECTIVE

Treatment with TNF-α inhibitors improve psoriasis with minimize/minor neutrophils infiltration and CXCL-1/8 expression in psoriatic lesions. However, the fine mechanism of TNF-α initiating psoriatic inflammation by tuning keratinocytes is unclear. Our previous research identified the deficiency of intracellular galectin-3 was sufficient to promote psoriasis inflammation characterized by neutrophil accumulation. This study aims to investigate whether TNF-α participated in psoriasis development through dysregulating galectin-3 expression.

METHODS

mRNA levels were assessed through quantitative real-time PCR. Flow cytometry was used to detect cell cycle/apoptosis. Western blot was used to evaluate the activation of the NF-κB signaling pathway. HE staining and immunochemistry were used to detect epidermal thickness and MPO expression, respectively. Specific small interfering RNA (siRNA) was used to knock down hsa-miR-27a-3p while plasmids transfection was used to overexpress galectin-3. Further, the multiMiR R package was utilized to predict microRNA-target interaction.

RESULTS AND DISCUSSION

We found that TNF-α stimulation altered cell proliferation and differentiation and promoted the production of psoriasis-related inflammatory mediators along with the inhibition of galectin-3 expression in keratinocytes. Supplement of galectin-3 could counteract the rise of CXCL-1/8 but not the other phenotypes of keratinocytes induced by TNF-α. Mechanistically, inhibition of the NF-κB signaling pathway could counteract the decrease of galectin-3 and the increase of hsa-miR-27a-3p expression whereas silence of hsa-miR-27a-3p could counteract the decrease of galectin-3 expression induced by TNF-α treatment in keratinocytes. Intradermal injection of murine anti-CXCL-2 antibody greatly alleviated imiquimod-induced psoriasis-like dermatitis.

CONCLUSION

TNF-α initiates psoriatic inflammation by increasing CXCL-1/8 in keratinocytes mediated by the axis of NF-κB-hsa-miR-27a-3p-galectin-3 pathway.

Galectin-3 Mediates Vascular Dysfunction in Obesity by Regulating NADPH Oxidase 1

BACKGROUND

Obesity is associated with increased risk of cardiovascular disease, but underlying mechanisms remain elusive. Metabolic dysfunction, especially hyperglycemia, is thought to be a major contributor, but how glucose impacts vascular function is unclear. GAL3 (galectin-3) is a sugar-binding lectin upregulated by hyperglycemia, but its role as a causative mechanism of cardiovascular disease remains poorly understood. Therefore, the objective of this study was to determine the role of GAL3 in regulating microvascular endothelial vasodilation in obesity.

METHODS

GAL3 was measured and found to be markedly increased in the plasma of overweight and obese patients, as well as in the microvascular endothelium of diabetic patients. To investigate causative mechanisms in cardiovascular disease, mice deficient in GAL3 were bred with obese db/db mice to generate lean, lean GAL3 knockout, obese, and obese GAL3 knockout genotypes. Endothelial cell-specific GAL3 knockout mice with novel AAV-induced obesity recapitulated whole-body knockout studies to confirm cell specificity.

RESULTS

Deletion of GAL3 did not alter body mass, adiposity, or plasma indices of glycemia and lipidemia, but levels of plasma reactive oxygen species as assessed by plasma thiobarbituric acid reactive substances were normalized in obese GAL3 knockout mice. Obese mice exhibited profound endothelial dysfunction and hypertension, both of which were rescued by GAL3 deletion. Isolated microvascular endothelial cells from obese mice had increased expression of NOX1 (nicotinamide adenine dinucleotide phosphate oxidase 1), which we have previously shown to contribute to increased oxidative stress and endothelial dysfunction, which was normalized in microvascular endothelium from mice lacking GAL3. Cell-specific deletion confirmed that endothelial GAL3 regulates obesity-induced NOX1 overexpression and subsequent microvascular function. Furthermore, improvement of metabolic syndrome by increasing muscle mass, improving insulin signaling, or treating with metformin decreased microvascular GAL3, and thereby NOX1, expression levels.

CONCLUSIONS

Deletion of GAL3 normalizes microvascular endothelial function in obese db/db mice, likely through a NOX1-mediated mechanism. Pathological levels of GAL3, and in turn NOX1, are amenable to improvements in metabolic status, presenting a potential therapeutic target to ameliorate pathological cardiovascular consequences of obesity.

Galectin-3 and RAGE differentially control advanced glycation endproduct-induced collagen damage in murine intervertebral disc organ culture

Background

Back and neck pain are leading causes of global disability that are associated with intervertebral disc (IVD) degeneration. Causes of IVD degeneration are multifactorial, and diet, age, and diabetes have all been linked to IVD degeneration. Advanced glycation endproducts (AGEs) accumulate in the IVD as a result of aging, diet, and diabetes, and AGE accumulation in the IVD has been shown to induce oxidative stress and catabolic activity that result in collagen damage. An association between AGE accumulation and IVD degeneration is emerging, yet mechanism behind this association remains unclear. The Receptor for AGEs (RAGE) is thought to induce catabolic responses in the IVD, and the AGE receptor Galectin 3 (Gal3) had a protective effect in other tissue systems but has not been evaluated in the IVD.

Methods

This study used an IVD organ culture model with genetically modified mice to analyze the roles of RAGE and Gal3 in an AGE challenge.

Results

Gal3 was protective against an AGE challenge in the murine IVD ex vivo, limiting collagen damage and biomechanical property changes. Gal3 receptor levels in the AF significantly decreased upon an AGE challenge. RAGE was necessary for AGE-induced collagen damage in the IVD, and RAGE receptor levels in the AF significantly increased upon AGE challenge.

Discussion

These findings suggest both RAGE and Gal3 are important in the IVD response to AGEs and highlight Gal3 as an important receptor with protective effects on collagen damage. This research improves understanding the mechanisms of AGE-induced IVD degeneration and suggests Gal3 receptor modulation as a potential target for preventative and therapeutic treatment for IVD degeneration.

Galectin-3 shapes toxic alpha-synuclein strains in Parkinson's disease

Parkinson's Disease (PD) is a neurodegenerative and progressive disorder characterised by intracytoplasmic inclusions called Lewy bodies (LB) and degeneration of dopaminergic neurons in the substantia nigra (SN). Aggregated α-synuclein (αSYN) is known to be the main component of the LB. It has also been reported to interact with several proteins and organelles. Galectin-3 (GAL3) is known to have a detrimental function in neurodegenerative diseases. It is a galactose-binding protein without known catalytic activity and is expressed mainly by activated microglial cells in the central nervous system (CNS). GAL3 has been previously found in the outer layer of the LB in post-mortem brains. However, the role of GAL3 in PD is yet to be elucidated. In post-mortem samples, we identified an association between GAL3 and LB in all the PD subjects studied. GAL3 was linked to less αSYN in the LB outer layer and other αSYN deposits, including pale bodies. GAL3 was also associated with disrupted lysosomes. In vitro studies demonstrate that exogenous recombinant Gal3 is internalised by neuronal cell lines and primary neurons where it interacts with endogenous αSyn fibrils. In addition, aggregation experiments show that Gal3 affects spatial propagation and the stability of pre-formed αSyn fibrils resulting in short, amorphous toxic strains. To further investigate these observations in vivo, we take advantage of WT and Gal3KO mice subjected to intranigral injection of adenovirus overexpressing human αSyn as a PD model. In line with our in vitro studies, under these conditions, genetic deletion of GAL3 leads to increased intracellular αSyn accumulation within dopaminergic neurons and remarkably preserved dopaminergic integrity and motor function. Overall, our data suggest a prominent role for GAL3 in the aggregation process of αSYN and LB formation, leading to the production of short species to the detriment of larger strains which triggers neuronal degeneration in a mouse model of PD.

Adipokines as Diagnostic and Prognostic Markers for the Severity of COVID-19

Accumulating evidence implicates obesity as a risk factor for increased severity of disease outcomes in patients infected with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). Obesity is associated with adipose tissue dysfunction, which not only predisposes individuals to metabolic complications, but also substantially contributes to low-grade systemic inflammation, altered immune cell composition, and compromised immune function. This seems to impact the susceptibility and outcome of diseases caused by viruses, as obese people appear more vulnerable to developing infections and they recover later from infectious diseases than normal-weight individuals. Based on these findings, increased efforts to identify suitable diagnostic and prognostic markers in obese Coronavirus disease 2019 (COVID-19) patients to predict disease outcomes have been made. This includes the analysis of cytokines secreted from adipose tissues (adipokines), which have multiple regulatory functions in the body; for instance, modulating insulin sensitivity, blood pressure, lipid metabolism, appetite, and fertility. Most relevant in the context of viral infections, adipokines also influence the immune cell number, with consequences for overall immune cell activity and function. Hence, the analysis of the circulating levels of diverse adipokines in patients infected with SARS-CoV-2 have been considered to reveal diagnostic and prognostic COVID-19 markers. This review article summarizes the findings aimed to correlate the circulating levels of adipokines with progression and disease outcomes of COVID-19. Several studies provided insights on chemerin, adiponectin, leptin, resistin, and galectin-3 levels in SARS-CoV-2-infected patients, while limited information is yet available on the adipokines apelin and visfatin in COVID-19. Altogether, current evidence points at circulating galectin-3 and resistin levels being of diagnostic and prognostic value in COVID-19 disease.

Galectin-3 Mediates Vascular Dysfunction in Obesity by Regulating NADPH Oxidase 1

Rationale

Obesity increases the risk of cardiovascular disease (CVD) through mechanisms that remain incompletely defined. Metabolic dysfunction, especially hyperglycemia, is thought to be a major contributor but how glucose impacts vascular function is unclear. Galectin-3 (GAL3) is a sugar binding lectin upregulated by hyperglycemia but its role as a causative mechanism of CVD remains poorly understood.

Objective

To determine the role of GAL3 in regulating microvascular endothelial vasodilation in obesity.

Methods and Results

GAL3 was markedly increased in the plasma of overweight and obese patients, as well as in the microvascular endothelium of diabetic patients. To investigate a role for GAL3 in CVD, mice deficient in GAL3 were bred with obese db/db mice to generate lean, lean GAL3 knockout (KO), obese, and obese GAL3 KO genotypes. GAL3 KO did not alter body mass, adiposity, glycemia or lipidemia, but normalized elevated markers of reactive oxygen species (TBARS) in plasma. Obese mice exhibited profound endothelial dysfunction and hypertension, both of which were rescued by GAL3 deletion. Isolated microvascular endothelial cells (EC) from obese mice had increased NOX1 expression, which we have previously shown to contribute to increased oxidative stress and endothelial dysfunction, and NOX1 levels were normalized in EC from obese mice lacking GAL3. EC-specific GAL3 knockout mice made obese using a novel AAV-approach recapitulated whole-body knockout studies, confirming that endothelial GAL3 drives obesity-induced NOX1 overexpression and endothelial dysfunction. Improved metabolism through increased muscle mass, enhanced insulin signaling, or metformin treatment, decreased microvascular GAL3 and NOX1. GAL3 increased NOX1 promoter activity and this was dependent on GAL3 oligomerization.

Conclusions

Deletion of GAL3 normalizes microvascular endothelial function in obese db/db mice, likely through a NOX1-mediated mechanism. Pathological levels of GAL3 and in turn, NOX1, are amenable to improvements in metabolic status, presenting a potential therapeutic target to ameliorate pathological cardiovascular consequences of obesity.

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.

Galectins as pivotal components in oncogenesis and immune exclusion in human malignancies

Galectins are galactoside-binding proteins, exerting numerous functions inside and outside the cell, particularly conferring adaptation to stress factors. For most of them, aberrant expression profiles have been reported in the context of cancer. Albeit not being oncogenic drivers, galectins can be harnessed to exacerbate the malignant phenotype. Their impact on disease establishment and progression is not limited to making cancer cells resistant to apoptosis, but is prominent in the context of the tumor microenvironment, where it fosters angiogenesis, immune escape and exclusion. This review focuses mainly on Gal-1, Gal-3 and Gal-9 for which the involvement in cancer biology is best known. It presents the types of galectin dysregulations, attempts to explain the mechanisms behind them and analyzes the different ways in which they favor tumour growth. In an era where tumour resistance to immunotherapy appears as a major challenge, we highlight the crucial immunosuppressive roles of galectins and the potential therapeutic benefits of combinatorial approaches including galectin inhibition.

The interplay of galectins-1, -3, and -9 in the immune-inflammatory response underlying cardiovascular and metabolic disease

Galectins are β-galactoside-binding proteins that bind and crosslink molecules via their sugar moieties, forming signaling and adhesion networks involved in cellular communication, differentiation, migration, and survival. Galectins are expressed ubiquitously across immune cells, and their function varies with their tissue-specific and subcellular location. Particularly galectin-1, -3, and -9 are highly expressed by inflammatory cells and are involved in the modulation of several innate and adaptive immune responses. Modulation in the expression of these proteins accompany major processes in cardiovascular diseases and metabolic disorders, such as atherosclerosis, thrombosis, obesity, and diabetes, making them attractive therapeutic targets. In this review we consider the broad cellular activities ascribed to galectin-1, -3, and -9, highlighting those linked to the progression of different inflammatory driven pathologies in the context of cardiovascular and metabolic disease, to better understand their mechanism of action and provide new insights into the design of novel therapeutic strategies.

A Physiological Approach to Inflammatory Markers in Obesity

Obesity is one of the most critical health problems all over the world; it is associated with metabolic dysfunction and overnutrition. Changes in the physiological function of adipose tissue, leading to altered secretion of adipocytokines, inflammatory mediators release, and chronic low-grade inflammation, are seen in obesity. Macrophages, neutrophils, CD4+ and CD8+ T cells, B cells, natural killer T (NKT) cells, eosinophils, mast cells, and adipocytes are involved in the inflammatory response that occurs during obesity. Various inflammatory markers are released from these cells. In this chapter, we will mention inflammatory mechanisms and markers of obesity.

Intermittent fasting and changes in Galectin-3: A secondary analysis of a randomized controlled trial of disease-free subjects

BACKGROUND AND AIMS

Intermittent fasting reduces risk of interrelated cardiometabolic diseases, including type 2 diabetes and heart failure (HF). Previously, we reported that intermittent fasting reduced homeostasis model assessment of insulin resistance (HOMA-IR) and Metabolic Syndrome Score (MSS) in the WONDERFUL Trial. Galectin-3 may act to reduce insulin resistance. This post hoc evaluation assessed whether intermittent fasting increased galectin-3.

METHODS AND RESULTS

The WONDERFUL Trial enrolled adults ages 21-70 years with ≥1 metabolic syndrome features or type 2 diabetes who were not taking anti-diabetic medication, were free of statins, and had elevated LDL-C. Subjects were randomized to water-only 24-h intermittent fasting conducted twice-per-week for 4 weeks and once-per-week for 22 weeks or to a parallel control arm with ad libitum energy intake. The study evaluated 26-week change scores of galectin-3 and other biomarkers. Overall, n = 67 subjects (intermittent fasting: n = 36; control: n = 31) completed the trial and had galectin-3 results. At 26-weeks, the galectin-3 change score was increased by intermittent fasting (median: 0.793 ng/mL, IQR: -0.538, 2.245) versus control (median: -0.332 ng/mL, IQR: -0.992, 0.776; p = 0.021). Galectin-3 changes correlated inversely with 26-week change scores of HOMA-IR (r = -0.288, p = 0.018) and MSS (r = -0.238, p = 0.052). Other HF biomarkers were unchanged by fasting.

CONCLUSION

A 24-h water-only intermittent fasting regimen increased galectin-3. The fasting-triggered galectin-3 elevation was inversely correlated with declines in HOMA-IR and MSS. This may be an evolutionary adaptive survival response that protects human health by modifying disease risks, including by reducing inflammation and insulin resistance.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02770313 (registered on May 12, 2016; first subject enrolled: November 30, 2016; final subject's 26-week study visit: February 19, 2020).

Galectin-3 S-glutathionylation regulates its effect on adipocyte insulin signaling

Protein-S-glutathionylation promotes redox signaling in physiological and oxidative distress conditions. Galectin-3 (Gal-3) promotes insulin resistance by down-regulating adipocyte insulin signaling, however, its S-glutathionylation and significance is not known. In this context, we report reversible S-glutathionylation of Gal-3. Site-directed mutagenesis established Gal-3 Cys187 as the putative S-glutathionylation site. Glutathionylated Gal-3 prevents Gal-3(WT)-Insulin Receptor interaction and facilitates insulin-induced murine adipocyte p-IRS1(tyr895) and p-AKT(ser473) signaling and glucose uptake in a Gal-3 Cys187 glutathionylation dependent manner in murine adipocytes, as assessed by Western blotting and 2-NBDG uptake assay respectively. Pre-glutathionylated Gal-3 at Cys187 resisted irreversible oxidation by H₂O₂. M2 macrophages showed enhanced Gal-3 S-glutathionylation when compared to M1 phenotype. Serum and stromal vascular fraction (SVF) isolated from control mice showed increased Gal-3 S-glutathionylation as compared to db/db mice. A significant increase in Gal-3 S-glutathionylation was observed in metformin-treated db/db mice when compared to db/db mice alone. Similar to murine, enhanced Gal-3 S-glutathionylation is observed in primary human monocyte derived M2 macrophages when compared to the M1 macrophage phenotype and Gal-3 regulates primary human adipocyte insulin signaling in a glutathionylation dependent manner. Collectively, we identified Gal-3 S-glutathionylation as a protective phenomenon, which relieves its inhibitory effect on adipocyte insulin signaling.

Trend of Galectin-3 Levels in Patients with Non-ST-Elevation and ST-Elevation Myocardial Infarction

Background and Objectives: Given the fact that galectin-3 has a predictive significance on the development of myocardial dysfunction after acute myocardial infarction, the aim of our study was to examine potential factors that could be important for the dynamics of the concentration of this biomarker in the early postinfarction period. Materials and Methods: This study included 89 patients with a diagnosis of stable angina pectoris (SAP) or the first non-ST elevation (NSTEMI) or ST-elevation (STEMI) myocardial infarction, who underwent percutaneous coronary intervention (PCI). The study group included 23 patients with the first NSTEMI and 42 patients with STEMI, while the control group consisted of 24 patients with SAP hospitalized for elective PCI without a previous MI. All patients had preserved left ventricular ejection fraction. Galectin-3 levels were determined on days 1, 5, and 30 after PCI. The significance of various independent variables as predictors of galectin-3 concentration was analyzed after a series of univariate linear regression modeling in a multivariate linear regression model. Results: The average patients’ age was 63.99 ± 9.13 years. Statistically significantly higher values of C-reactive protein were established in STEMI compared to SAP (p < 0.01) or NSTEMI (p < 0.001), whereas WBC count was significantly lower in SAP than in STEMI (p < 0.001) and NSTEMI (p < 0.01) group. Although there were no statistically significant differences in measured galectin-3 concentrations between the examined groups on days 1, 5, and 30 after PCI, HTA, triglyceride level, LA size, treatment with trimetazidine and long-acting nitrates, as well as percentage of LM stenosis and E/A ratio were identified as independent predictors of galectin-3 concentration. Conclusions: In the post-MI period, very early values of galectin-3 correlate mostly with atherosclerosis factors, while on day 30 this biomarker correlates with diastolic dysfunction and “announces” left ventricular remodeling.

Diagnostic Value of Serum Concentration of Galectin-3 in Patients With Heart Failure With Preserved Ejection Fraction

BACKGROUND

Although the predictive value of galectin-3 for heart failure with preserved ejection fraction has been demonstrated, the diagnostic value remains unclear. The present study was performed to address this issue.

HYPOTHESIS

Galectin-3 has diagnostic value for heart failure with preserved ejection fraction.

METHODS

This is a diagnostic experiment. We conducted an observational study of 223 patients with combined symptoms of heart failure and diseases that can lead to heart failure with preserved ejection fraction. Patients were grouped into the heart failure group and control group in accordance with the 2016 European Society of Cardiology heart failure guidelines for heart failure with preserved ejection fraction. Baseline information and serum galectin-3 concentration were assessed within 24 h after admission.

RESULTS

Serum galectin-3 concentration was significantly higher in the heart failure group compared with the control group. Binary logistic regression analysis showed that higher galectin-3 concentration was associated with the occurrence of heart failure with preserved ejection fraction. The area under the curve of galectin-3 was 0.763, indicating that galectin-3 has moderate diagnostic value for heart failure with preserved ejection fraction. Galectin-3 >15.974 ng/mL identified heart failure with preserved ejection fraction with 76.0% sensitivity and 71.9% specificity.

CONCLUSIONS

There was a correlation between galectin-3 and heart failure with preserved ejection fraction, and galectin-3 was an independent predictor of heart failure with preserved ejection fraction. The diagnostic value of galectin-3 for heart failure with preserved ejection fraction was moderate (AUC: 0.763, 95% CI: 0.696-0.821, P < 0.01, and the sensitivity is 76.0% while the specificity is 71.9% at the threshold 15.974 ng/mL) and was higher than that of interventricular septal thickness or E/A ratio.

Underestimated Prediabetic Biomarkers: Are We Blind to Their Strategy?

Type 2 Diabetes (T2D) is currently one of the fastest growing health challenging, a non-communicable disease result of the XXI century lifestyle. Given its growing incidence and prevalence, it became increasingly imperative to develop new technologies and implement new biomarkers for early diagnosis in order to promote lifestyle changes and thus cause a setback of the disease. Promising biomarkers have been identified as predictive of T2D development; however, none of them have yet been implemented in clinical practice routine. Moreover, many prediabetic biomarkers can also represent potential therapeutical targets in disease management. Previous studies have identified the most popular biomarkers, which are being thoroughly investigated. However, there are some biomarkers with promising preliminary results with limited associated studies; hence there is still much to be understood about its mechanisms and associations in T2D pathophysiology. This work identifies and discusses the promising results of Galectin-3, Ophthalmate and Fetuin-A.

Peripheral oscillometric arterial performance does not depict coronary status in patients with type 2 diabetes mellitus

BACKGROUND

Arterial stiffness is associated with cardiovascular events. Matrix metalloproteases (MMPs), their tissue inhibitors (TIMPs) and galectin-3 are involved in the pathogenesis of end organ damage. This study aimed to evaluate the contribution of arterial stiffness, MMPs, TIMPs and galectin-3 with the current vascular status in type 2 diabetes mellitus (T2DM).

METHODS

74 patients with T2DM, 36 with coronary heart disease (CHD) (T2DM + CHD) and 38 without CHD (T2DM - CHD) were included. Aortic pulse wave velocity (PWVao), aortic and brachial augmentation indices (AIx aortic and AIx brachial) and central-aortic blood pressure values were determined by non-invasive arteriography. MMPs, TIMPs and galectin-3 plasma concentrations were analysed by ELISA.

RESULTS

Patients with T2DM and CHD presented with significantly increased arterial stiffness determined as AIx and significantly elevated values for TIMP-4 and galectin-3. Heterogeneous peripheral vascular status regardless of the CHD status was observed, and increasing severity of CHD was associated with an increased arterial stiffness. TIMP-4 correlated significantly with an elevated PWVao in the whole cohort independently from CHD status.

CONCLUSION

Determination of arterial stiffness is an effective and, compared to laboratory markers, more reliable method for determining the peripheral vascular situation in patients with T2DM, but it does not clearly depict coronary situation.

In Vivo Human Single-Chain Fragment Variable Phage Display-Assisted Identification of Galectin-3 as a New Biomarker of Atherosclerosis

Background

Atherosclerosis is a complex pathology in which dysfunctional endothelium, activated leucocytes, macrophages, and lipid‐laden foam cells are implicated, and in which plaque disruption is driven by many putative actors. This study aimed to identify accurate targetable biomarkers using new in vivo approaches to propose tools for improved diagnosis and treatment.

Methods and Results

Human scFv (single‐chain fragment variable) selected by in vivo phage display in a rabbit model of atherosclerosis was reformatted as scFv fused to the scFv‐Fc (single‐chain fragment variable fused to the crystallizable fragment of immunoglobulin G format) antibodies. Their reactivity was tested using flow cytometry and immunoassays, and aorta sections from animal models and human carotid and coronary artery specimens. A pool of atherosclerotic proteins from human endarterectomies was co‐immunoprecipitated with the selected scFv‐Fc followed by mass spectrometry for target identification. Near‐infrared fluorescence imaging was performed in Apoe^−/− mice after injection of an Alexa Fluor 647–labeled scFv‐Fc‐2c antibody produced in a baculovirus system with 2 additional cysteine residues (ie, 2c) for future coupling to nano‐objects for theranostic applications. One scFv‐Fc clone (P3) displayed the highest cross‐reactivity against atherosclerotic lesion sections (rabbit, mouse, and human) and was chosen for translational development. Mass spectrometry identified galectin‐3, a β‐galactoside‐binding lectin, as the leader target. ELISA and immunofluorescence assays with a commercial anti‐galectin‐3 antibody confirmed this specificity. P3 scFv‐Fc‐2c specifically targeted atherosclerotic plaques in the Apoe^−/− mouse model.

Conclusions

These results provide evidence that the P3 antibody holds great promise for molecular imaging of atherosclerosis and other inflammatory pathologies involving macrophages. Recently, galectin‐3 was proposed as a high‐value biomarker for the assessment of coronary and carotid atherosclerosis.

Physical Activity Attenuates the Obesity-Induced Dysregulated Expression of Brown Adipokines in Murine Interscapular Brown Adipose Tissue

In recent years, brown adipose tissue (BAT), which has a high heat-producing capacity, has been confirmed to exist even in adults, and it has become a focal point for the prevention and the improvement of obesity and lifestyle-related diseases. However, the influences of obesity and physical activity (PA) on the fluid factors secreted from BAT (brown adipokines) are not well understood. In this study, therefore, we focused on brown adipokines and investigated the effects of obesity and PA. The abnormal expressions of gene fluid factors such as galectin-3 (Lgals3) and Lgals3 binding protein (Lgals3bp), whose proteins are secreted from HB2 brown adipocytes, were observed in the interscapular BAT of obese mice fed a high-fat diet for 4 months. PA attenuated the abnormalities in the expressions of these genes. Furthermore, although the gene expressions of factors related to brown adipocyte differentiation such as peroxisome proliferator-activated receptor gamma coactivator 1-α were also down-regulated in the BAT of the obese mice, PA suppressed the down-regulation of these factors. On the other hand, lipogenesis was increased more in HB2 cells overexpressing Lgals3 compared with that in control cells, and the overexpression of Lgals3bp decreased the mitochondrial mass. These results indicate that PA attenuates the obesity-induced dysregulated expression of brown adipokines and suggests that Lgals3 and Lgals3bp are involved in brown adipocyte differentiation.

Associations of galectin-3 expression and LGALS-3 (rs4652) gene variant with coronary artery disease risk in diabetics

Background

Galectin-3 protein encoded by lectin galactoside-binding soluble-3 (LGALS-3) gene is an important genetic factor in type 2 diabetes mellitus (T2DM) and its cardiovascular obstacles in various populations. We aimed to elicit the pro-inflammatory effect of galectin-3 as determined by interleukin-6 (IL-6) serum levels and to explore the relationship between galectin-3 (LGALS-3 rs4652) gene variant and its expression levels with coronary artery disease (CAD) risk among T2DM Egyptian patients.

Methods

112 lean subjects were compared to 100 T2DM without CAD and 84 T2DM with CAD. A tetra-primer amplification refractory mutation system polymerase chain reaction was used to test LGALS-3 (rs4652), and galectin3 expression was tested with a quantitative real-time polymerase chain reaction. Serum IL-6 was measured using an enzyme-linked immunosorbent assay.

Results

We found that the prevalence of LGALS-3 (rs4652) AC genotype and galectin-3 gene expression levels in T2DM with CAD were significantly higher than the additional 2 groups and were correlated positively to IL-6 circulating levels. Also, the C allele carriers (AC+CC) had significantly higher relative Galectin-3 expression levels compared to the A allele carriers (AA).

Conclusions

We concluded that galectin-3 expression levels and LGALS-3 (rs4652) AC genotype were coronary artery disease risk factors in people with type two diabetes among an Egyptian sample.

Prevalence of periodontitis in obese patients in Bahrain: a cross-sectional study

Background

Adult obesity has been associated with various systemic diseases and is an increasing problem in Bahrain. Recent evidence indicates a correlation between adult obesity and periodontitis. Hence the aim of this study was to assess the prevalence of periodontitis in overweight/obese adults in Bahrain and to determine the factors associated with periodontitis in these obese adults.

Method

This cross-sectional study was conducted in overweight subjects attending Ministry of Health (MOH) Nutrition Clinics at primary health centers in Bahrain. After obtaining the institutional ethics approval, the demographic and anthropometric data, including Body Mass Index (BMI) and waist circumference (WC) using World Health Organization (WHO) thresholds for severity of obesity, were recorded. Periodontal status was measured using the Community Periodontal Index (CPI) and the extent and severity of periodontal disease were categorized according to the number of sextants with CPI codes 3 and 4.

Results

A total of 372 participated with a mean age 44.0 (± 10.5) years for males, and 42.5 (± 11.2) years for females. Periodontitis was present in 361 (97%) of participants. Hypertension and diabetes were the most prevalent co-morbidities at 23.4% and 16% respectively. Mean WC was significantly greater in males at 114 cm (± 15.6) compared to females 109.5 cm (± 12.5) (p < 0.001). BMI was not associated with severity or extent of periodontitis but WC was weakly correlated in males but not in females (Spearman rho =  + 0.2, p < 0.05). In the logistic regression model using overall WC to predict the severity of periodontitis, the adjusted OR was 1.02 (95% CI 1.00–1.04) and for age it was 1.05 (95% CI 1.00–1.07).

Conclusion

The prevalence of periodontitis was high in this sample of overweight Bahrainis. BMI was not correlated with periodontitis but WC had a weak positive correlation. Implementation of periodontal health screening as a routine part of a nutrition clinic program is recommended.

Leptin, Galectin-3 and Angiotensin II Type 1 Receptor Polymorphism in Overweight and Obese Patients with Heart Failure - Role and Functional Interplay

Background and Aims

Leptin, one of the best-known adipocytes, together with the renin-angiotensin-aldosterone system and galectin-3 are important players in inflammation, arterial hypertension and heart failure pathophysiology. Moreover, uninucleotide A1166C polymorphism is associated with hypertension and poor prognosis in heart failure. The aim of the study was to investigate a possible relationship between leptin serum values, specific heart failure biomarkers and the presence of AT1 receptor A1166C polymorphism in overweight and obese heart failure patients.

Methods

The study included 88 consecutive overweight and obese patients admitted for decompensated heart failure. NT-proBNP, MR-proANP, galectin-3 and leptin levels were determined on the arrival day. Genotyping of the A1166C allele – AT1 receptor gene was performed in all patients in order to find variants.

Results

We found a strong positive correlation (r = 0.347, p = 0.001) between leptin serum concentrations and BMI. Leptin levels were not correlated with heart failure biomarkers (NT-proBNP, MR-proANP and galectin-3). All homozygote CC variants were hypertensive, but we registered no significant difference in genetic AC and AA variants distribution between hypertensive and normotensive. Leptin was not significantly modified by the presence of potentially pathogenic A1166C–AT 1 receptor genotypes (AC + CC). But, galectin-3 was found in higher concentrations in patients with heterozygous and homozygous A1166C mutations.

Conclusion

Overweight and obese patients with heart failure display high leptin serum levels. Leptin does not offer incremental prognostic value in heart failure overweight and obese patients. But, galectin-3 was found in higher concentrations in patients with heterozygous and homozygous A1166C mutations, suggesting a worse prognosis probably due to more advanced cardiac fibrosis.

RAGE silencing deters CML-AGE induced inflammation and TLR4 expression in endothelial cells

The N^ε-(carboxymethyl)lysine (CML), the predominant advanced glycation end products (AGEs) in diabetes and its RAGE induced cytokine release has been well explored. But the CML mediated multiple AGEs receptor expression is still not understood and the role played by RAGE silencing in modulating CML generated pro-inflammatory cytokines in micro and macrovascular endothelial cells is yet to be studied. HUVEC and HREC cells were exposed with CML for 24 h. RAGE, AGER1, AGER2, Gal-3, TLR4, TLR2, CD36, FEEL-1, FEEL-2, and chemokine HMGB1 were quantified by either qPCR/western blotting. The receptor's expression was also determined in control vs diabetic retina. Expression of pro-inflammatory genes, ROS, and mitochondrial membrane potential change were assessed using ELISA, DCFDA, and JC-1 method respectively. RAGE expression was silenced either by Si-RAGE or neutralising antibody with anti-RAGE and expression of other AGE receptors, adaptors, and signalling pathway were studied compared with Si-Control. CML activated RAGE, TLR4, HMGB1(p < 0.001) and Gal-3 (p < 0.05) expression in both micro and macro vascular cells. Cadaveric diabetic retinal tissues also showed increased expression of RAGE, TLR4 and HMGB1 (p < 0.05). RAGE silencing significantly reduced TLR4, HMGB1 (p < 0.05) expression and inhibited the phosphorylation of NFκB and ERK1/2 in both these cells. The TLR4 adaptors MyD88 and TIRAP (p < 0.05) showed down regulation on RAGE silencing. This study shows CML induces AGE receptors expression as observed in diabetic retina and RAGE silencing down regulated TLR4 signalling and cytokine release by partly modulating TLR4 adaptors which needs further validation. From this study we speculate targeting the TLR4 adaptors like MyD88 and TIRAP can be a potential therapeutic target for reducing diabetic induced vascular complications.

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.

Association of circulating galectin-3 with gestational diabetes mellitus, progesterone, and insulin resistance

BACKGROUND/OBJECTIVE

Because galectin-3 has been proposed to regulate obesity and insulin resistance in mice, we hypothesized that circulating galectin-3 levels are associated with presence of gestational diabetes mellitus (GDM), progesterone, and insulin resistance.

METHODS

Circulating galectin-3 levels were measured using an enzyme-linked immunosorbent assay (ELISA) in women with GDM (n = 137) and their controls (n = 81). Associations of galectin-3 and progesterone with GDM and insulin resistance were evaluated using regression models.

RESULTS

Circulating galectin-3 levels were increased in the individuals with GDM (P < .001) and associated significantly with progesterone (r = 0.42, P < .001), gestational age at sampling (r = 0.23, P < .001), current body mass index (BMI; r = 0.17, P = .02), estrogen (r = 0.15, P < .03), fasting glucose (r = 0.41, P < .001), fasting insulin (r = 0.39, P < .001), and homeostasis model assessment of insulin resistance (HOMA-IR; r = 0.44, P < .001). After adjustment for potential confounders, including current BMI, subjects in the highest tertile of galectin-3 levels were more likely to have GDM (odds ratio 4.71, 95% confidence interval 2.01-11.06) as compared with the lowest tertile. The association between circulating galectin-3 levels and GDM remained significant after adjusting for progesterone, but significantly attenuated after adjustment with HOMA-IR. Furthermore, the multiple linear regression analyses after adjustment for confounders showed an independent association between galectin-3 levels and HOMA-IR (β = .41, P < .001), suggesting that association of circulating gelactin-3 levels with GDM might be mediated via insulin resistance. Progesterone demonstrated the expected associations with galectin-3, GDM, and HOMA-IR.

CONCLUSIONS

Circulating galectin-3 levels are associated with GDM possibly through increased insulin resistance. The association of galectin-3 with progesterone highlights a potential role of progesterone in its interaction with galectin-3.

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.

Galectin-3 gene deletion results in defective adipose tissue maturation and impaired insulin sensitivity and glucose homeostasis

Adiposopathy is a pathological adipose tissue (AT) response to overfeeding characterized by reduced AT expandability due to impaired adipogenesis, which favors inflammation, insulin resistance (IR), and abnormal glucose regulation. However, it is unclear whether defective adipogenesis causes metabolic derangement also independently of an increased demand for fat storage. As galectin-3 has been implicated in both adipocyte differentiation and glucose homeostasis, we tested this hypothesis in galectin-3 knockout (Lgal3^−/−) mice fed a standard chow. In vitro, Lgal3^−/− adipocyte precursors showed impaired terminal differentiation (maturation). Two-month-old Lgal3^−/− mice showed impaired AT maturation, with reduced adipocyte size and expression of adipogenic genes, but unchanged fat mass and no sign of adipocyte degeneration/death or ectopic fat accumulation. AT immaturity was associated with AT and whole-body inflammation and IR, glucose intolerance, and hyperglycemia. Five-month-old Lgal3^−/− mice exhibited a more mature AT phenotype, with no difference in insulin sensitivity and expression of inflammatory cytokines versus WT animals, though abnormal glucose homeostasis persisted and was associated with reduced β-cell function. These data show that adipogenesis capacity per se affects AT function, insulin sensitivity, and glucose homeostasis independently of increased fat intake, accumulation and redistribution, thus uncovering a direct link between defective adipogenesis, IR and susceptibility to diabetes.

Alzheimer's disease and type 2 diabetes mellitus: A systematic review of proteomic studies

Similar to dementia, the risk for developing type 2 diabetes mellitus (T2DM) increases with age, and T2DM also increases the risk for dementia, particularly Alzheimer's disease (AD). Although T2DM is primarily a peripheral disorder and AD is a central nervous system disease, both share some common features as they are chronic and complex diseases, and both show involvement of oxidative stress and inflammation in their progression. These characteristics suggest that T2DM may be associated with AD, which gave rise to a new term, type 3 diabetes (T3DM). In this study, we searched for matching peripheral proteomic biomarkers of AD and T2DM based in a systematic review of the available literature. We identified 17 common biomarkers that were differentially expressed in both patients with AD or T2DM when compared with healthy controls. These biomarkers could provide a useful workflow for screening T2DM patients at risk to develop AD.

Could Galectin 3 Be a Good Prognostic Factor in Endometrial Cancer?

Galectin 3 is a modulator of several basic biological functions. It may be involved in the development of obesity and type 2 diabetes—risk factors of endometrial cancer. The study involved 144 patients, after abrasion due to postmenopausal bleeding. Galectin 3 concentrations were quantified in serum by multiplex fluorescent bead-based immunoassays. Median serum galectin 3 concentrations revealed significant differences between FIGO III and IV vs. FIGO I and II patients. Statistically higher concentrations were reported for patients with lymph node metastases compared to patients without it (p = 0.001) as well as in patients with lymphovascular space invasion compared to patients without LVSI (p = 0.02). No statistically significant differences were observed for median of galectin 3 levels depending on the surgical procedure (laparoscopy vs. laparotomy, p = 0.0608). Patients with galectin 3 levels exceeding the median value were characterized by overall survival being shorter by 11.9 months. High levels of galectin 3 were correlated with shorter disease-free survival, the difference is up to 14.8 months. Galectin 3 can be an independent prognostic factor in patients with endometrial cancer. Among the recognized prognostic factors and the concentrations of the galectin 3 marker at the adopted time points, the univariate analysis showed a significant effect of staging, grading, and cutoff galectin 3 on the OS. For multivariate analysis, the galectin 3 cutoff point had the greatest significant impact on OS.

miR-124-3p increases in high glucose induced osteocyte-derived exosomes and regulates galectin-3 expression: A possible mechanism in bone remodeling alteration in diabetic periodontitis

The mechanisms underlying the two-way relationship between diabetes mellitus (DM) and periodontitis are unclear. We examined a possible effect of galectin-3 (Gal-3), a factor in DM and bone metabolism, on periodontitis with or without DM. Using enzyme-linked immunosorbent assay, we detected saliva Gal-3 in patients with periodontitis, with or without type 2 diabetes mellitus (T2DM). In animal models, we measured periodontal bone microarchitecture via micro computed tomography, and detected Gal-3, Runt-related transcription factor 2 (Runx2), and interleukin-6 (IL-6) expression in alveolar bone. Applying dual luciferase reporter assay, we explored the target binding of miR-124-3p and Gal-3. We examined osteocyte-derived exosomes with transmission electron microscopy and detected miR-124-3p, Gal-3, and IL-6 expression in exosomes. Saliva Gal-3 was increased in DM compared with controls but decreased in patients with moderate periodontitis and DM compared with those who had moderate periodontitis only. Alveolar bone mass was increased in DM and exacerbated in DM with periodontitis. Gal-3 and Runx2 were both increased in periodontitis and DM compared with controls, but decreased in DM with periodontitis compared with DM alone. MiR-124-3p targeted and inhibited Gal-3 expression in vitro. Osteocytes secreted exosomes carrying miR-124-3p, Gal-3, and IL-6, which were influenced by high glucose. These findings indicate that osteocyte-derived exosomes carrying miR-124-3p may regulate Gal-3 expression of osteoblasts, especially under high-glucose conditions, suggesting a possible mechanism for DM-related alveolar bone pathologies.

The Emerging Role of Galectins and O-GlcNAc Homeostasis in Processes of Cellular Differentiation

Galectins are a family of soluble β-galactoside-binding proteins with diverse glycan-dependent and glycan-independent functions outside and inside the cell. Human cells express twelve out of sixteen recognized mammalian galectin genes and their expression profiles are very different between cell types and tissues. In this review, we summarize the current knowledge on the changes in the expression of individual galectins at mRNA and protein levels in different types of differentiating cells and the effects of recombinant galectins on cellular differentiation. A new model of galectin regulation is proposed considering the change in O-GlcNAc homeostasis between progenitor/stem cells and mature differentiated cells. The recognition of galectins as regulatory factors controlling cell differentiation and self-renewal is essential for developmental and cancer biology to develop innovative strategies for prevention and targeted treatment of proliferative diseases, tissue regeneration, and stem-cell therapy.

Increased serum levels of advanced glycation end products due to induced molting in hen layers trigger a proinflammatory response by peripheral blood leukocytes

Induced molting (IM), a severe detriment to animal welfare, is still used in the poultry industry in some countries to increase or rejuvenate egg production and is responsible for several physiological perturbations, possibly including reactive oxidative stress, a form of metabolic stress. Because metabolic stress has been shown to induce a proinflammatory response involved in attempts to restore homeostasis, we hypothesized that similar responses followed IM. To confirm this hypothesis, we initially confirmed the establishment of oxidative stress during IM in 75-wk-old layers by demonstrating increased production of advanced glycation end products (AGE). Concomitant with increased oxidative metabolites, cellular stress was demonstrated in peripheral blood leukocytes (PBL) by increased levels of stress gene products (the glucocorticoid receptor, sirtuin-1, and heat shock protein 70 mRNA). Increased expression of stress proteins in PBL was followed by a proinflammatory response as demonstrated by increased levels of proinflammatory gene products (IL-6 and IL-1β mRNA); increased expression of these gene products was also demonstrated in direct response to AGE in vitro, thus establishing a direct link between oxidative and cellular stress. To establish a possible pathway for inducing a proinflammatory response by PBL, we showed that AGE increased a time dependent expression of galactin-3, Toll-like receptor-4, and nuclear factor - κB, all involved in the proinflammatory activation pathway. In vivo, AGE formed complexes with increased levels of circulating acute phase proteins (lysozyme and transferrin), products of a proinflammatory immune response, thereby demonstrating an effector response to cope with the consequences of oxidative stress. Thus, the harmful consequences of IM for animal welfare are extended here by demonstrating the activation of a resource-demanding proinflammatory response.

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.

Inhibition of Galectin-3 Alleviates Cigarette Smoke Extract-Induced Autophagy and Dysfunction in Endothelial Progenitor Cells

Endothelial progenitor cells (EPCs) have the potential to repair damaged blood vessels and promote angiogenesis. Smoking, an important risk factor for cardiovascular diseases, is associated with impaired functions of EPCs. However, the underlying mechanisms remain unclear. The aim of the study was to investigate the effects of cigarette smoke extract (CSE) on autophagy and dysfunction of EPCs and the involvement of galectin-3 in its effects. EPCs were treated with 8% CSE for 24 h (without affecting cell viability). EPC functions were assessed by tube formation and migration capacity and intracellular ROS and eNOS expression. Autophagy was assessed by autophagic protein expression by Western blotting and immunofluorescence microscopy and autophagosome accumulation by transmission electron microscopy. Galectin-3 expression was measured by real-time PCR, Western blotting, and immunofluorescence microscopy, while phospho-AMPK and phospho-mTOR were measured by Western blotting. EPCs were transfected by shRNA-Gal-3 or shRNA-NC before treatment with CSE to examine the effects of galectin-3 on CSE-induced autophagy and dysfunction of EPCs. CSE-treated EPCs showed decreased tube formation and migration ability and eNOS expression but increased oxidative stress. CSE also induced autophagy which was characterized by a decrease in p62 protein, an increase in LC3B-II/I ratio, and accumulation of autophagosomes. CSE upregulated galectin-3 expression on EPCs. Inhibition of galectin-3 abrogated CSE-induced autophagy and dysfunction of EPCs. CSE activated phospho-AMPK and inhibited phospho-mTOR, and inhibition of galectin-3 abolished CSE's effect on activating phospho-AMPK and inhibiting phospho-mTOR. In conclusion, our results suggest that galectin-3 mediates CSE-induced EPC autophagy and dysfunction, likely via the AMPK/mTOR signaling pathway.

Berberine inhibits adipocyte differentiation, proliferation and adiposity through down-regulating galectin-3

This study is designed to investigate the effects of berberine (BBR) on galectin-3 (Gal-3) and the relationships to its suppressive activities on adipocyte differentiation, proliferation and adiposity. Our results showed that BBR greatly suppressed the differentiation and proliferation of mouse primary preadipocytes isolated from epididymal white adipose tissue (eWAT), during which the expression level of Gal-3 was down-regulated significantly. Overexpression of Gal-3 totally abolished the suppressive activities of BBR on Gal-3 expression, preadipocyte differentiation and proliferation. BBR reduced Gal-3 promoter activity, destabilized its mRNA and inhibited firefly luciferase activity of a recombinant plasmid containing the Gal-3 3′ untranslated region (UTR). Furthermore, BBR up-regulated microRNA (miRNA) let-7d expression and the suppressive activity on Gal-3 3′UTR was abolished by point mutation on the let-7d binding site. In mice fed a high-fat diet (HFD), BBR up-regulated let-7d and down-regulated Gal-3 expression in eWAT; it also suppressed adipocyte differentiation and proliferation and reduced adiposity greatly. In summary, our study proves that BBR inhibits the differentiation and proliferation of adipocytes through down-regulating Gal-3, which is closely associated with its anti-obesity effect. Our results may support the future clinical application of BBR for the treatment of obesity or related diseases.

Galectin-3 is involved in HIV-1 expression through NF-κB activation and associated with Tat in latently infected cells

Galectin-3 (Gal-3) is involved in many biological processes and pathogenesis of diseases in part through nuclear factor (NF)-κB activation. We demonstrated that Gal-3 expression was significantly induced by tumor necrosis factor (TNF)-α or phorbol 12-myristate 13-acetate in OM-10.1 and ACH-2 cells, which are considered as a model of HIV-1 latently infected cells. The expression of Gal-3 was also associated with their viral production. However, the induction of Gal-3 by TNF-α was not observed in their uninfected parental cells. Knockdown of Gal-3 resulted in the suppression of NF-κB activation and HIV-1 replication in the latently infected cells. The expression level of Gal-3 was highly correlated with that of HIV-1 Tat in the latently infected cells stimulated with TNF-α. Furthermore, colocalization and possible interaction of Gal-3 and Tat were observed in the stimulated cells. These results suggent that Gal-3 expression is closely correlated with HIV-1 expression in latently infected cells through NF-κB activation and the interaction with Tat.

Micro-environment and intracellular metabolism modulation of adipose tissue macrophage polarization in relation to chronic inflammatory diseases

The accumulation and pro-inflammatory polarization of immune cells, mainly macrophages, in adipose tissue (AT) are considered crucial factors for obesity-induced chronic inflammatory diseases. In this review, we highlighted the role of adipose tissue macrophage (ATM) polarization on AT function in the obese state and the effect of the micro-environment and intracellular metabolism on the dynamic switch of ATMs into their pro-inflammatory or anti-inflammatory phenotypes, which may have distinct influences on obesity-related chronic inflammatory diseases. Obesity-associated metabolic dysfunctions, including those of glucose, fatty acid, cholesterol, and other nutrient substrates such as vitamin D and iron in AT, promote the pro-inflammatory polarization of ATMs and AT inflammation via regulating the interaction between ATMs and adipocytes and intracellular metabolic pathways, including glycolysis, fatty acid oxidation, and reverse cholesterol transportation. Focusing on the regulation of ATM metabolism will provide a novel target for the treatment of obesity-related chronic inflammatory diseases, including insulin resistance, cardiovascular diseases, and cancers.

Mice lacking galectin-3 (Lgals3) function have decreased home cage movement

Background

Galectins are a large family of proteins evolved to recognize specific carbohydrate moieties. Given the importance of pattern recognition processes for multiple biological tasks, including CNS development and immune recognition, we examined the home cage behavioral phenotype of mice lacking galectin-3 (Lgals3) function. Using a sophisticated monitoring apparatus capable of examining feeding, drinking, and movement at millisecond temporal and 0.5 cm spatial resolutions, we observed daily behavioral patterns from 10 wildtype male C57BL/6J and 10 Lgals3 constitutive knockout (Lgals3^−/−; both cohorts aged 2–3 months) mice over 17 consecutive days. We performed a second behavioral assessment of this cohort at age 6–7 months.

Results

At both ages, Lgals3^−/− mice demonstrated less movement compared to wildtype controls. Both forward locomotion and movement-in-place behaviors were decreased in Lgals3^−/− mice, due to decreased bout numbers, initiation rates, and durations. We additionally noted perturbation of behavioral circadian rhythms in Lgals3^−/− mice, with mice at both ages demonstrating greater variability in day-to-day performance of feeding, drinking, and movement (as assessed by Lomb-Scargle analysis) compared to wildtype.

Conclusion

Carbohydrate recognition tasks performed by Lgals3 may be required for appropriate development of CNS structures involved in the generation and control of locomotor behavior.

Electronic supplementary material

The online version of this article (10.1186/s12868-018-0428-x) contains supplementary material, which is available to authorized users.

Inhibition of galectin-3 ameliorates the consequences of cardiac lipotoxicity in a rat model of diet-induced obesity

Obesity is accompanied by metabolic alterations characterized by insulin resistance and cardiac lipotoxicity. Galectin-3 (Gal-3) induces cardiac inflammation and fibrosis in the context of obesity; however, its role in the metabolic consequences of obesity is not totally established. We have investigated the potential role of Gal-3 in the cardiac metabolic disturbances associated with obesity. In addition, we have explored whether this participation is, at least partially, acting on mitochondrial damage. Gal-3 inhibition in rats that were fed a high-fat diet (HFD) for 6 weeks with modified citrus pectin (MCP; 100 mg/kg/day) attenuated the increase in cardiac levels of total triglyceride (TG). MCP treatment also prevented the increase in cardiac protein levels of carnitine palmitoyl transferase IA, mitofusin 1, and mitochondrial complexes I and II, reactive oxygen species accumulation and decrease in those of complex V but did not affect the reduction in ¹⁸F-fluorodeoxyglucose uptake observed in HFD rats. The exposure of cardiac myoblasts (H9c2) to palmitic acid increased the rate of respiration, mainly due to an increase in the proton leak, glycolysis, oxidative stress, β-oxidation and reduced mitochondrial membrane potential. Inhibition of Gal-3 activity was unable to affect these changes. Our findings indicate that Gal-3 inhibition attenuates some of the consequences of cardiac lipotoxicity induced by a HFD since it reduced TG and lysophosphatidyl choline (LPC) levels. These reductions were accompanied by amelioration of the mitochondrial damage observed in HFD rats, although no improvement was observed regarding insulin resistance. These findings increase the interest for Gal-3 as a potential new target for therapeutic intervention to prevent obesity-associated cardiac lipotoxicity and subsequent mitochondrial dysfunction.

Summary: Inhibition of Gal-3 activity reduced the excessive cardiac accumulation of lipids in rats fed a high fat diet. This was accompanied by the amelioration of mitochondria damage observed in obese rats.

Mouse Thyroid Gland Changes in Aging: Implication of Galectin-3 and Sphingomyelinase

Prevalence of thyroid dysfunction and its impact on cognition in older people has been demonstrated, but many points remain unclarified. In order to study the effect of aging on the thyroid gland, we compared the thyroid gland of very old mice with that of younger ones. We have first investigated the changes of thyroid microstructure and the possibility that molecules involved in thyroid function might be associated with structural changes. Results from this study indicate changes in the height of the thyrocytes and in the amplitude of interfollicular spaces, anomalous expression/localization of thyrotropin, thyrotropin receptor, and thyroglobulin aging. Thyrotropin and thyrotropin receptor are upregulated and are distributed inside the colloid while thyroglobulin fills the interfollicular spaces. In an approach aimed at defining the behavior of molecules that change in different physiopathological conditions of thyroid, such as galectin-3 and sphingomyelinase, we then wondered what was their behavior in the thyroid gland in aging. Importantly, in comparison with the thyroid of young animals, we have found a higher expression of galectin-3 and a delocalization of neutral sphingomyelinase in the thyroid of old animals. A possible relationship between galectin-3, neutral sphingomyelinase, and aging has been discussed.

Galectin-3 levels relate in children to total body fat, abdominal fat, body fat distribution, and cardiac size

Galectin-3 has recently been proposed as a novel biomarker for cardiovascular disease in adults. The purpose of this investigation was to assess relationships between galectin-3 levels and total body fat, abdominal fat, body fat distribution, aerobic fitness, blood pressure, left ventricular mass, left atrial size, and increase in body fat over a 2-year period in a population-based sample of children. Our study included 170 children aged 8-11 years. Total fat mass and abdominal fat were measured by dual-energy x-ray absorptiometry (DXA). Body fat distribution was expressed as abdominal fat/total fat mass. Maximal oxygen uptake was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure and pulse pressure were measured. Left atrial size, left ventricular mass, and relative wall thickness were measured by echocardiography. Frozen serum samples were analyzed for galectin-3 by the Proximity Extension Assay technique. A follow-up DXA scan was performed in 152 children 2 years after the baseline exam. Partial correlations, with adjustment for sex and age, between galectin-3 versus body fat measurements indicated weak to moderate relationships. Moreover, left atrial size, left ventricular mass, and relative wall thickness and pulse pressure were also correlated with galectin-3. Neither systolic blood pressure nor maximal oxygen uptake was correlated with galectin-3. There was also a correlation between galectin-3 and increase in total body fat over 2 years, while no such correlations were found for the other fat measurements.

CONCLUSION

More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker for cardiovascular disease in adults. • Information on this subject in children is very scarce. What is New: • The present study demonstrates a relationship between galectin-3 levels and total body fat, abdominal fat, body fat distribution, cardiac size and geometry, and increase in total body fat over 2 years in young children.

Galectin-3: an emerging biomarker in stroke and cerebrovascular diseases

The carbohydrate-binding molecule galectin-3 has garnered significant attention recently as a biomarker for various conditions ranging from cardiac disease to obesity. Although there have been several recent studies investigating its role in stroke and other cerebrovascular diseases, awareness of this emerging biomarker in the wider neurology community is limited. We performed a systematic search in PubMed, Embase, Scopus, CINAHL, Clinicaltrials.gov and the Cochrane library in November and December 2016 for articles related to galectin-3 and cerebrovascular disease. We included both human and pre-clinical studies in order to provide a comprehensive view of the state of the literature on this topic. The majority of the relevant literature focuses on stroke, cerebral ischemia and atherosclerosis, but some recent attention has also been devoted to intracranial and subarachnoid hemorrhage. Higher blood levels of galectin-3 correlate with worse outcomes in atherosclerotic disease as well as in intracranial and subarachnoid hemorrhage in human studies. However, experimental evidence supporting the role of galectin-3 in these phenotypes is not as robust. It is likely that the role of galectin-3 in the inflammatory cascade within the central nervous system following injury is responsible for many of its effects, but its varied physiological functions and multiple sites of expression mean that it may have different effects depending on the nature of the disease condition and the time since injury. In summary, experimental and human research raises the possibility that galectin-3, which is closely linked to the inflammatory cascade, could be of value as a prognostic marker and therapeutic target in cerebrovascular disease.

Role of Galectin-3 in Bone Cell Differentiation, Bone Pathophysiology and Vascular Osteogenesis

Galectin-3 is expressed in various tissues, including the bone, where it is considered a marker of chondrogenic and osteogenic cell lineages. Galectin-3 protein was found to be increased in the differentiated chondrocytes of the metaphyseal plate cartilage, where it favors chondrocyte survival and cartilage matrix mineralization. It was also shown to be highly expressed in differentiating osteoblasts and osteoclasts, in concomitance with expression of osteogenic markers and Runt-related transcription factor 2 and with the appearance of a mature phenotype. Galectin-3 is expressed also by osteocytes, though its function in these cells has not been fully elucidated. The effects of galectin-3 on bone cells were also investigated in galectin-3 null mice, further supporting its role in all stages of bone biology, from development to remodeling. Galectin-3 was also shown to act as a receptor for advanced glycation endproducts, which have been implicated in age-dependent and diabetes-associated bone fragility. Moreover, its regulatory role in inflammatory bone and joint disorders entitles galectin-3 as a possible therapeutic target. Finally, galectin-3 capacity to commit mesenchymal stem cells to the osteoblastic lineage and to favor transdifferentiation of vascular smooth muscle cells into an osteoblast-like phenotype open a new area of interest in bone and vascular pathologies.