Pediatric reference values of NT-proBNP and Galectin-3 based on a French cohort.

BACKGROUND: In pediatric cardiology, the fact that some new biomarkers have assay-specific normal values has to be considered for correct clinical decisions. The current study aimed to provide age-adjusted normative values for NT-proBNP and Galectin-3 using the Abbott immunoassay system from a prospective French pediatric cohort sera collection and to validate our data for NT-proBNP on a second retrospective cohort. METHODS: We analyzed 283 consecutive samples for NT-proBNP and 140 samples for Galectin-3 collected from apparently healthy children (0-18 years) with outpatient treatment at our institution (Hôpital Necker-Enfants malades, Paris, France) during 24 months. RESULTS: For NT-proBNP and Galectin-3, we establish four age partitions, respectively two (<2 years / >2 years) and establish upper reference values and their 90 % CI for each biomarker (Galectin-3 (ng/mL): 56 [44-70] / 26 [23-29]). We evaluated the diagnostic performance of our upper reference values of NT-proBNP on a retrospective cohort (n = 428) with positive predictive value of 0.92. CONCLUSIONS: Using Abbott immunoassay system, we report age-specific reference values for NT-proBNP and for the first time for Galectin-3 in a healthy French pediatric cohort. These data call for larger cohort studies to define more robustly percentiles and diagnostic performance for NT-proBNP.

Oligosaccharides from Stellaria dichotoma L. var. lanceolate bind to galectin-3 and ameliorate effects of colitis.

Even though Stellaria dichotoma L. var. lanceolate (S. dichotoma) is a well-known medicinal plant in the family Caryophyllaceae, its oligosaccharides remain unexplored in terms of their potential as bioactive agents. Here, we isolated a mixture of oligosaccharides from S. dichotoma (Yield: 12 % w/w), that are primarily non-classical raffinose family oligosaccharides (RFOs). Nine major oligosaccharides were purified and identified from the mixture, including sucrose, raffinose, 1-planteose, lychnose, stellariose, along with four new non-classical RFOs. Two of the four new oligosaccharides are linear hexose pentamers with α-galactosyl extensions on their lychnose moieties, and the other two are branched hexose hexamers with α-galactosyl extensions on their stellariose groups. Their interactions with galectin-3 (Gal-3) revealed significant binding, with the terminal galactose providing enhanced affinity for the lectin. Notably, Gal-3 residues Arg144, His158, Asn160, Arg162, Asn174, Trp181, Glu184 and Arg186 coordinate with the lychnose. In vivo studies using the dextran sulfate sodium (DSS) mouse model for colitis demonstrated the ability of these carbohydrates in mitigating ulcerative colitis (UC). Overall, our study has provided structural information and potential applications of S. dichotoma oligosaccharides, also offers new approaches for the development of medicinal oligosaccharides.

In vitro and in vivo effects of Galectin-3 inhibitor TD139 on inflammation and ERK/JNK/p38 pathway in gestational diabetes mellitus.

This study aims to investigate the effects of the Galectin-3 (Gal-3) inhibitor TD139 on inflammation and the extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK)/p38 pathway in gestational diabetes mellitus (GDM). Human placental tissues were treated with TD139 and TNF-α, assessing Gal-3, ERK/JNK/p38 activation, and inflammatory cytokines. GDM was induced in mice via subcutaneous injections of streptozotocin (STZ). After confirming GDM, mice were treated with 15 mg/kg TD139 on GD 10.5 12.5, 14.5, 16.5, and 18.5. Serum inflammatory cytokines were measured on GD 20.5, and post-delivery placental tissues were analyzed. Data were analyzed using one-way or two-way repeated measures ANOVA with post hoc tests. TD139 suppressed TNF-α-induced increases in Gal-3, IL-1ß, IL-6, MCP-1, and ERK/JNK/p38 activation in placental tissues. In STZ-induced GDM mice, TD139 reduced glucose levels, weight loss, and food and water intake. TD139 significantly lowered TNF-α, IL-1ß, IL-6, and MCP-1 in serum and placental tissues and inhibited the ERK/JNK/p38 pathway. TD139 improved pup numbers in GDM mice compared to untreated ones. TD139 reduces inflammation and inhibits the ERK/JNK/p38 pathway in TNF-α stimulated placental tissues and STZ-induced GDM mice, suggesting its therapeutic potential for managing GDM-related placental inflammation and improving pregnancy outcomes. The study used TNF-α to mimic GDM in placental tissues and an STZ-induced GDM mouse model, which may not fully represent human GDM complexity. Future research should explore alternative models, and broader signaling pathways, and thoroughly evaluate TD139's safety in pregnancy.

Hepatic Mac2-BP expression depends on liver fibrosis and inflammation due to fat accumulation in patients with metabolic dysfunction-associated steatotic liver disease.

AIM: Data on the upregulation of Mac-2 binding protein (M2BP) expression associated with fat accumulation in the liver are limited. Therefore, we aimed to assess the relationship between hepatic M2BP expression and changes in the liver microenvironment due to fat accumulation in patients with metabolic dysfunction associated steatotic liver disease (MASLD). METHODS: Liver specimens obtained from 46 patients with MASLD were subjected to immunohistochemical staining to visualize M2BP expression in the liver. The staining intensity in the hepatocytes and sinusoidal cells was classified as high or low grade. First, the correlation between hepatic M2BP expression and microenvironmental changes caused by fat accumulation was examined. Then, the influence of hepatic M2BP expression on serum M2BP glycosylation isomer levels in patients with MASLD was evaluated. RESULTS: The staining grade of M2BP was higher in the sinusoidal cells than in the hepatocytes (p = 0.015). The patients with high staining grade in their hepatocytes had more severe lobular inflammation than those with low staining grade (p = 0.037). Additionally, the patients with high staining grade in their sinusoidal cells presented more severe fibrosis than those with low staining grade (p = 0.018). The staining grade in the hepatocytes correlated positively with serum M2BP glycosylation isomer levels (p = 0.023), whereas no correlation was observed between sinusoidal staining grade and serum M2BP glycosylation isomer levels (p = 0.393). CONCLUSIONS: Fat accumulation in patients with MASLD leads to M2BP expression in hepatocytes due to liver inflammation and that in sinusoidal cells due to fibrosis.

Diagnostic Modalities in Heart Failure: A Narrative Review.

Heart failure (HF) can present acutely or progress over time. It can lead to morbidity and mortality affecting 6.5 million Americans over the age of 20. The HF type is described according to the ejection fraction classification, defined as the percentage of blood volume that exits the left ventricle after myocardial contraction, undergoing ejection into the circulation, also called stroke volume, and is proportional to the ejection fraction. Cardiac catheterization is an invasive procedure to evaluate coronary artery disease leading to HF. Several biomarkers are being studied that could lead to early detection of HF and better symptom management. Testing for various biomarkers in the patient's blood is instrumental in confirming the diagnosis and elucidating the etiology of HF. There are various biomarkers elevated in response to increased myocardial stress and volume overload, including B-type natriuretic peptide (BNP) and its N-terminal prohormone BNP. We explored online libraries such as PubMed, Google Scholar, and Cochrane to find relevant articles. Our narrative review aims to extensively shed light on diagnostic modalities and novel techniques for diagnosing HF.

Heart failure biomarkers in revascularized patients with stable coronary heart disease as clinical outcome predictors.

Introduction: The aim of this study was to investigate serum levels of galectin-3 (Gal-3) and N-terminal pro-brain Natriuretic Peptide (NT-proBNP) in patients with stable obstructive coronary artery disease, as well as their potential to predict clinical outcomes. Methods: This was a single-center cross-sectional cohort study. 168 patients were divided into three groups: percutaneous coronary intervention (PCI) group (N 64), coronary artery bypass graft surgery (CABG) group (N 57), and group with no coronary stenosis (N 47). Gal-3 and NT-proBNP levels were measured and the Syntax score (Ss) was calculated. Results: The mean value of Gal-3 was 19.98 ng/ml and 9.51 ng/ml (p < 0.001) in the study group and control group, respectively. Highest value of Gal-3 was found in the group of subjects with three-vessel disease (p < 0.001). The mean value of NT-proBNP in the study group was 401.3 pg/ml, and in the control group 100.3 pg/ml (p = 0.159). The highest value of NT-proBNP was found in the group of subjects with three-vessel disease (p = 0.021). There was a statistically significant association between Gal-3, NT-proBNP and occurrence of adverse cardiovascular event (p = 0.0018; p = 0.0019). Conclusion: Gal-3 and NT-proBNP could be used as an additional tool for diagnosis and severity assessment of stable obstructive coronary artery disease. Furthermore, it could help identify high-risk patients who could experience major adverse cardiovascular events.

Exploration into Galectin-3 Driven Endocytosis and Lattices.

Essentially all plasma membrane proteins are glycosylated, and their activity is regulated by tuning their cell surface dynamics. This is achieved by glycan-binding proteins of the galectin family that either retain glycoproteins within lattices or drive their endocytic uptake via the clathrin-independent glycolipid-lectin (GL-Lect) mechanism. Here, we have used immunofluorescence-based assays to analyze how lattice and GL-Lect mechanisms affect the internalization of the cell adhesion and migration glycoprotein α5ß1 integrin. In retinal pigment epithelial (RPE-1) cells, internalized α5ß1 integrin is found in small peripheral endosomes under unperturbed conditions. Pharmacological compounds were used to competitively inhibit one of the galectin family members, galectin-3 (Gal3), or to inhibit the expression of glycosphingolipids, both of which are the fabric of the GL-Lect mechanism. We found that under acute inhibition conditions, endocytic uptake of α5ß1 integrin was strongly reduced, in agreement with previous studies on the GL-Lect driven internalization of the protein. In contrast, upon prolonged inhibitor treatment, the uptake of α5ß1 integrin was increased, and the protein was now internalized by alternative pathways into large perinuclear endosomes. Our findings suggest that under these prolonged inhibitor treatment conditions, α5ß1 integrin containing galectin lattices are dissociated, leading to an altered endocytic compartmentalization.

Galectin-3 Predicts Long-Term Risk of Cerebral Disability and Mortality in Out-of-Hospital Cardiac Arrest Survivors.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is associated with high mortality and cerebral disability in survivors. Current models of risk prediction and survival are mainly based on resuscitation duration. We examined the prognostic value of circulating biomarkers in predicting mortality and severe cerebral disability for OHCA survivors, alongside traditional clinical risk indicators. METHODS: Biomarkers including BNP, troponin I, and galectin-3 were measured at hospital admission in resuscitated OHCA patients. Prognostic significance for mortality and cerebral disability involving circulating biomarkers, resuscitation duration, demographics, and laboratory and clinical characteristics was examined via univariate and multivariate Cox proportional hazards regression models. The incremental prognostic value of the index covariates was examined through model diagnostics, focusing on the Akaike information criterion (AIC) and Harrell's concordance statistic (c-statistic). RESULTS: In a combinatorial analysis of 144 OHCA survivors (median follow-up 5.7 years (IQR 2.9-6.6)), BNP, galectin-3, arterial pH, and resuscitation time were significant predictors of all-cause death and severe cerebral disability, whereas troponin I levels were not. Multivariate regression, adjusting for BNP, arterial pH, and resuscitation time, identified galectin-3 as an independent predictor of long-term mortality. Multiple linear regression models also confirmed galectin-3 as the strongest predictor of cerebral disability. The incorporation of galectin-3 into models for predicting mortality and cerebral disability enhanced fit and discrimination, demonstrating the incremental value of galectin-3 beyond traditional risk predictors. CONCLUSIONS: Galectin-3 is a significant, independent long-term risk predictor of cerebral disability and mortality in OHCA survivors. Incorporating galectin-3 into current risk stratification models may enhance early prognostication and guide targeted clinical interventions.

Natriuretic peptides and soluble ST2 improves echocardiographic diagnosis of elevated left ventricular filling pressures.

Elevated filling pressure of the left ventricle (LV) defines diastolic dysfunction. The gold standard for diagnosis is represented by the measurement of LV end-diastolic pressure (LVEDP) during cardiac catheterization, but it has the disadvantage of being an invasive procedure. This study aimed to investigate the correlation between LVEDP and cardiac serum biomarkers such as natriuretic peptides (mid-regional pro-atrial natriuretic peptide [MR-proANP], B-type natriuretic peptide [BNP], and N-terminal prohormone BNP [NT-proBNP]), soluble ST2 (sST2), galectin-3 and mid-regional pro-adrenomedullin (MR-proAMD). Consecutive patients hospitalized in a tertiary center and undergoing left cardiac catheterization were included in the study. Diastolic dysfunction was considered present if the end-expiratory LVEDP was ≥ 15 mmHg. Cardiac biomarkers were determined from pre-procedural peripheral venous blood samples. A total of 110 patients were included, of whom 76 (69.0%) were males, with a median age of 65 (55-71) years. Median LVEDP was 13.5 (8-19) mmHg and diastolic dysfunction was present in 50 (45.4%) of the patients. LVEDP correlated with BNP (p < 0.0001, r = 0.39 [0.20-0.53]), NT-proBNP (p < 0.0001, r = 0.40 [0.22-0.55]), MR-proANP (p = 0.001, r = 0.30 [0.11-0.46]), sST2 (p < 0.0001, r = 0.47 [0.30-0.60]), but not with MR-proAMD (p = 0.77) or galectin-3 (p = 0.76). In the final stepwise multivariable binary logistic regression model, diastolic dysfunction was predicted by NT-proBNP, mitral average E/e', sST2, atrial fibrillation, and left atrium reservoir strain. BNP, NT-proBNP, MR-proANP, and sST2 had predictive value for diastolic dysfunction. In contrast, galectin-3 and MR-proAMD were not associated with increased filling pressures. Furthermore, NT-proBNP and sST2 significantly improved diastolic dysfunction prediction in the final multivariable model.

Unlocking the role of Galectin-3: Implications for sleep disorders and health.

Galectin-3 is a member of the lectin family, and is an intriguing protein that is found in diverse tissues across the body. It is known for its multifaceted involvement in various physiological functions, including tissue repair, immune function and neuroinflammation in the central nervous system. It also serves as a paracrine signal, promoting the growth of certain cells and contributing to fibrosis, while higher levels of Galectin-3 in the bloodstream correlate with an increased risk of mortality and cardiovascular disease-related outcomes in the general population. Recent scientific studies have identified a potential link between Galectin-3 and sleep disorders. However, the precise mechanisms through which galectin-3 influences sleep disorders remain an active area of investigation. Although initial studies suggest a potential association between Galectin-3 and sleep disruptions, including conditions, such as insomnia, insufficient sleep time, and obstructive sleep apnea, further research is required to establish a more definitive relationship. This review explores recent findings regarding the potential connection between Galectin-3 and sleep patterns, and offers insights into the complex interplay between this protein and sleep. These discoveries present promising prospects for the development of innovative therapeutic approaches aimed at sleep disorder management, using Galectin-3 as a potential target for interventions or as a biomarker for sleep health.

The GPI sidechain of Toxoplasma gondii inhibits parasite pathogenesis.

Glycosylphosphatidylinositols (GPIs) are highly conserved anchors for eukaryotic cell surface proteins. The apicomplexan parasite, Toxoplasma gondii, is a widespread intracellular parasite of warm-blooded animals whose plasma membrane is covered with GPI-anchored proteins, and free GPIs called GIPLs. While the glycan portion is conserved, species differ in sidechains added to the triple mannose core. The functional significance of the Glcα1,4GalNAcß1- sidechain reported in Toxoplasma gondii has remained largely unknown without understanding its biosynthesis. Here we identify and disrupt two glycosyltransferase genes and confirm their respective roles by serology and mass spectrometry. Parasites lacking the sidechain on account of deletion of the first glycosyltransferase, PIGJ, exhibit increased virulence during primary and secondary infections, suggesting it is an important pathogenesis factor. Cytokine responses, antibody recognition of GPI-anchored SAGs, and complement binding to PIGJ mutants are intact. By contrast, the scavenger receptor CD36 shows enhanced binding to PIGJ mutants, potentially explaining a subtle tropism for macrophages detected early in infection. Galectin-3, which binds GIPLs, exhibits an enhancement of binding to PIGJ mutants, and the protection of galectin-3 knockout mice from lethality suggests that Δpigj parasite virulence in this context is sidechain dependent. Parasite numbers are not affected by Δpigj early in the infection in wild-type mice, suggesting a breakdown of tolerance. However, increased tissue cysts in the brains of mice infected with Δpigj parasites indicate an advantage over wild-type strains. Thus, the GPI sidechain of T. gondii plays a crucial and diverse role in regulating disease outcomes in the infected host.IMPORTANCEThe functional significance of sidechain modifications to the glycosylphosphatidylinositol (GPI) anchor in parasites has yet to be determined because the glycosyltransferases responsible for these modifications have not been identified. Here we present identification and characterization of both Toxoplasmsa gondii GPI sidechain-modifying glycosyltransferases. Removal of the glycosyltransferase that adds the first GalNAc to the sidechain results in parasites without a sidechain on the GPI, and increased host susceptibility to infection. Loss of the second glycosyltransferase results in a sidechain with GalNAc alone, and no glucose added, and has negligible effect on disease outcomes. This indicates GPI sidechains are fundamental to host-parasite interactions.

A Few Charged Residues in Galectin-3's Folded and Disordered Regions Regulate Phase Separation.

Proteins with intrinsically disordered regions (IDRs) often undergo phase separation to control their functions spatiotemporally. Changing the pH alters the protonation levels of charged sidechains, which in turn affects the attractive or repulsive force for phase separation. In a cell, the rupture of membrane-bound compartments, such as lysosomes, creates an abrupt change in pH. However, how proteins' phase separation reacts to different pH environments remains largely unexplored. Here, using extensive mutagenesis, NMR spectroscopy, and biophysical techniques, it is shown that the assembly of galectin-3, a widely studied lysosomal damage marker, is driven by cation-π interactions between positively charged residues in its folded domain with aromatic residues in the IDR in addition to π-π interaction between IDRs. It is also found that the sole two negatively charged residues in its IDR sense pH changes for tuning the condensation tendency. Also, these two residues may prevent this prion-like IDR domain from forming rapid and extensive aggregates. These results demonstrate how cation-π, π-π, and electrostatic interactions can regulate protein condensation between disordered and structured domains and highlight the importance of sparse negatively charged residues in prion-like IDRs.

Targeting AnxA2-EGFR signaling: hydroxychloroquine as a therapeutic strategy for bleomycin-induced pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a disease that causes progressive failure of lung function, and its molecular mechanism remains poorly understood. However, the AnnexinA2-epidermal growth factor receptor (EGFR) signaling pathway has been identified as playing a significant role in its development. Hydroxychloroquine, a common anti-malarial drug, has been found to inhibit this pathway and slow down the progression of IPF. To better understand the role of the AnxA2-EGFR signaling pathway in pulmonary fibrosis, an in vivo study was conducted. In this study, mice were induced with pulmonary fibrosis using bleomycin, and HCQ was administered intraperitoneally the next day of bleomycin induction. The study also employed nintedanib as a positive control. After the induction, the lungs showed increased levels of fibronectin and vimentin, along with enhanced expression of AnxA2, EGFR, and Gal-3, indicating pulmonary fibrosis. Additionally, the study also found that HCQ significantly inhibited these effects and showed antifibrotic properties similar to nintedanib. Overall, these findings suggest that HCQ can attenuate bleomycin-induced pulmonary fibrosis by inhibiting the AnxA2-EGFR signaling pathway. These results are promising for developing new treatments for IPF.

Significance of Galectin-3 and N-terminal pro b-type natriuretic peptide in the prediction of atrial fibrillation after cardiac surgery.

Background: Post-operative atrial fibrillation (POAF) is a frequent complication after cardiac surgery. It is associated with prolonged hospital stay, increased morbidity, mortality rate and economic costs. The aim of the study was to determine the association between the values of Galectin3 and N-terminal pro-B-type natriuretic peptide (NTproBNP) with POAF after cardiac surgery. Methods: A prospective study enrolled patients aged 18-85 years old admitted due to elective coronary artery bypass graft surgery (CABG) or CABG + aortic valve replacement. The plasma Galectin-3 and NT-proBNP levels were measured one day before surgery postoperative days 1 and 7. Results: The study included a total of 103 patients. POAF was registered in 45 patients. The mean age of patients in whom POAF occurred was 68.8 years, while other patients' mean age was 65.5 years (p=0.028). Patients with POAF did not differ from the group without POAF in the values of Galectin-3 and NT-proBNP preoperatively as well as on the first and seventh postoperative days. Changes in Galectin-3 levels on the first postoperative day had statistically significant value for predicting POAF (AUC=0.627 0.509-0.745 , p<0.05). Decrease in Galectin-3 level con centration on the first postoperative day over 17% increases the risk of developing AF. Conclusions: Preoperative values of Galectin-3 and NTproBNP are not associated with POAF development after cardiac surgery.

The correlation between ultrasonographic morphology and structure of the left atrial appendage, blood flow velocity, and plasma galectin-3 levels with thrombus formation in the left atrial appendage of patients with atrial fibrillation.

Background: To explore the correlation between left atrial appendage morphology, blood flow velocity and plasma galectin-3 and thrombosis in patients with atrial fibrillation. Methods: Patients with atrial fibrillation who received treatment and completed ultrasound examination in hospital from 2022 to December 2023 were enrolled. According to whether there was left atrial appendage thrombosis, the patients were divided into a control group (no left atrial appendage thrombosis was found) and a study group (left atrial appendage thrombosis was found). The morphology and structure of the left atrial appendage, blood flow velocity and plasma galectin-3 level were recorded exploring its correlation with left atrium thrombosis. Results: A total of 330 patients with atrial fibrillation were enrolled, including 278 in the control group and 52 in the study group. Left group and the control group of morphological structure differences (P < 0.05). The main lobe length, ostial area, longest diameter, shortest diameter, left atrial appendage volume and left atrial volume in the study group were higher than those in the control group (P < 0.05). The left atrial appendage emptying velocity, filling velocity and left ventricular ejection fraction of the study group were lower than those of the control group, and the left ventricular end-diastolic diameter was higher than that of the control group (P < 0.05). Group of white blood cell count, neutrophils/lymphocyte ratio, plasma galactose lectin-3 levels were higher than control group (P < 0.05). ROC curve analysis of left atrial appendage emptying velocity, left atrial appendage filling velocity, left atrial enddiastolic diameter and left atrial ejection fraction had higher diagnostic value (P < 0.05). Conclusions: Left atrial appendage morphology, blood flow velocity and plasma galectin-3 level are important factors to evaluate the risk of left atrial appendage thrombosis in patients with atrial fibrillation. This study improves the understanding of thrombosis, further elucidates the risk factors for thrombosis, and improves patient prognosis.

Combined High-Throughput Proteomics and Random Forest Machine-Learning Approach Differentiates and Classifies Metabolic, Immune, Signaling and ECM Intra-Tumor Heterogeneity of Colorectal Cancer.

Colorectal cancer (CRC) is a frequent, worldwide tumor described for its huge complexity, including inter-/intra-heterogeneity and tumor microenvironment (TME) variability. Intra-tumor heterogeneity and its connections with metabolic reprogramming and epithelial-mesenchymal transition (EMT) were investigated with explorative shotgun proteomics complemented by a Random Forest (RF) machine-learning approach. Deep and superficial tumor regions and distant-site non-tumor samples from the same patients (n = 16) were analyzed. Among the 2009 proteins analyzed, 91 proteins, including 23 novel potential CRC hallmarks, showed significant quantitative changes. In addition, a 98.4% accurate classification of the three analyzed tissues was obtained by RF using a set of 21 proteins. Subunit E1 of 2-oxoglutarate dehydrogenase (OGDH-E1) was the best classifying factor for the superficial tumor region, while sorting nexin-18 and coatomer-beta protein (beta-COP), implicated in protein trafficking, classified the deep region. Down- and up-regulations of metabolic checkpoints involved different proteins in superficial and deep tumors. Analogously to immune checkpoints affecting the TME, cytoskeleton and extracellular matrix (ECM) dynamics were crucial for EMT. Galectin-3, basigin, S100A9, and fibronectin involved in TME-CRC-ECM crosstalk were found to be differently variated in both tumor regions. Different metabolic strategies appeared to be adopted by the two CRC regions to uncouple the Krebs cycle and cytosolic glucose metabolism, promote lipogenesis, promote amino acid synthesis, down-regulate bioenergetics in mitochondria, and up-regulate oxidative stress. Finally, correlations with the Dukes stage and budding supported the finding of novel potential CRC hallmarks and therapeutic targets.

The role of galectin-3 in bone homeostasis: A review.

The skeletal system maintains a delicate balance known as bone homeostasis, which is essential for the lifelong preservation of bone mass, shape, and integrity. This equilibrium relies on a complex interplay between bone marrow mesenchymal stem cells (BMSCs), osteoblasts, osteocytes, and osteoclasts. Galectin-3 (Gal-3), a chimeric galectin with a unique N-terminal tail and a conserved carbohydrate recognition domain (CRD) at its C-terminus, has emerged as a critical regulator in bone homeostasis. The CRD of Gal-3 mediates carbohydrate binding, while its N-terminal tail is implicated in oligomerization and phase separation, which are vital for its functionality. Gal-3's multivalency is central to its role in a range of cellular activities, including inflammation, immune response, apoptosis, cell adhesion, and migration. Imbalances in bone homeostasis often arise from disruptions in osteoblast differentiation and activity, increased osteoclast differentiation and activity. Gal-3's influence on these processes suggests its significant role in the regulation of bone remodeling. This review will examine the molecular mechanisms through which Gal-3 contributes to bone remodeling and discuss its potential as a therapeutic target for the treatment of bone-related disorders.

Galectin-2 Agglutinates Helicobacter pylori via Lipopolysaccharide Containing H Type I Under Weakly Acidic Conditions.

Galectins are ß-galactoside-binding animal lectins involved in various biological functions, such as host defense. Galectin-2 and -3 are members of the galectin family that are expressed in the stomach, including the gastric mucosa and surface mucous cells. Galectin-3 exhibits aggregation and bactericidal activity against Helicobacter pylori in a ß-galactoside-dependent manner. We previously reported that galectin-2 has the same activity under neutral pH conditions. In this study, the H. pylori aggregation activity of galectin-2 was examined under weakly acidic conditions, in which H. pylori survived. Galectin-2 agglutinated H. pylori even at pH 6.0, but not at pH 5.0, correlating with its structural stability, as determined using circular dichroism. Additionally, galectin-2 binding to the lipopolysaccharide (LPS) of H. pylori cultured under weakly acidic conditions was investigated using affinity chromatography and Western blotting. Galectin-2 could bind to H. pylori LPS containing H type I, a Lewis antigen, in a ß-galactoside-dependent manner. In contrast, galectin-3 was structurally more stable than galectin-2 under acidic conditions and bound to H. pylori LPS containing H type I and Lewis X. In conclusion, galectin-2 and -3 might function cooperatively in the defense against H. pylori in the stomach under different pH conditions.

Relative bioavailability and food effect of the galectin-3 inhibitor selvigaltin (GB1211) administered as a tablet in healthy participants (GALBA-1).

PURPOSE: Overexpression of galectin-3, a ß-galactoside-binding lectin, is associated with fibrotic diseases and cancer. Selvigaltin is an oral galectin-3 inhibitor, previously administered as a 50 mg capsule. This study aimed to evaluate the relative bioavailability and food effect of selvigaltin as a 100 mg tablet in healthy volunteers. METHODS: In this single-dose, randomized, three-period, crossover study (GALBA-1; NCT05747573), participants received selvigaltin as a 100 mg tablet (under fasted and fed conditions) or as two 50 mg capsules (under fasted conditions). Primary endpoints included plasma and urine pharmacokinetic (PK) parameters. Secondary endpoints were safety and tolerability. RESULTS: Of the 13 enrolled participants, 12 completed the study. Under fasted conditions, geometric mean maximum observed plasma concentration (Cmax) and systemic exposure (AUC0─inf) of selvigaltin were 161.0% and 84.0% higher, respectively, after administration of a tablet vs. capsules. Under fed vs. fasted conditions, geometric mean Cmax of the selvigaltin tablet was 20.0% lower, whereas AUC0─inf was unaffected. Geometric mean percentage of total dose of selvigaltin excreted in urine over 0─96 h was 30.3% and 35.9% for the tablet under fasted and fed conditions, respectively, and 14.5% for the capsules. No treatment-emergent severe or serious adverse events or study discontinuations due to a treatment-emergent adverse event were reported. CONCLUSION: The tablet formulation of selvigaltin displayed higher bioavailability vs. the capsule formulation, with minimal effect of food on PK. Selvigaltin was well-tolerated during all treatments. These findings warrant further clinical development of the tablet formulation of selvigaltin without specific food restrictions. CLINICAL TRIAL REGISTRATION: NCT05747573; February 28, 2023.

Targeting Myeloid Differentiation Primary Response Protein 88 (MyD88) and Galectin-3 to Develop Broad-Spectrum Host-Mediated Therapeutics against SARS-CoV-2.

Nearly six million people worldwide have died from the coronavirus disease (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although COVID-19 vaccines are largely successful in reducing the severity of the disease and deaths, the decline in vaccine-induced immunity over time and the continuing emergence of new viral variants or mutations underscore the need for an alternative strategy for developing broad-spectrum host-mediated therapeutics against SARS-CoV-2. A key feature of severe COVID-19 is dysregulated innate immune signaling, culminating in a high expression of numerous pro-inflammatory cytokines and chemokines and a lack of antiviral interferons (IFNs), particularly type I (alpha and beta) and type III (lambda). As a natural host defense, the myeloid differentiation primary response protein, MyD88, plays pivotal roles in innate and acquired immune responses via the signal transduction pathways of Toll-like receptors (TLRs), a type of pathogen recognition receptors (PRRs). However, recent studies have highlighted that infection with viruses upregulates MyD88 expression and impairs the host antiviral response by negatively regulating type I IFN. Galectin-3 (Gal3), another key player in viral infections, has been shown to modulate the host immune response by regulating viral entry and activating TLRs, the NLRP3 inflammasome, and NF-κB, resulting in the release of pro-inflammatory cytokines and contributing to the overall inflammatory response, the so-called "cytokine storm". These studies suggest that the specific inhibition of MyD88 and Gal3 could be a promising therapy for COVID-19. This review presents future directions for MyD88- and Gal3-targeted antiviral drug discovery, highlighting the potential to restore host immunity in SARS-CoV-2 infections.