Galectin-3 inhibition ameliorates hypoxia-induced pulmonary artery hypertension

Glycopolymer Inhibitors of Galectin-3 Suppress the Markers of Tissue Remodeling in Pulmonary Hypertension

Pulmonary hypertension is a cardiovascular disease with a low survival rate. The protein galectin-3 (Gal-3) binding β-galactosides of cellular glycoproteins plays an important role in the onset and development of this disease. Carbohydrate-based drugs that target Gal-3 represent a new therapeutic strategy in the treatment of pulmonary hypertension. Here, we present the synthesis of novel hydrophilic glycopolymer inhibitors of Gal-3 based on a polyoxazoline chain decorated with carbohydrate ligands. Biolayer interferometry revealed a high binding affinity of these glycopolymers to Gal-3 in the subnanomolar range. In the cell cultures of cardiac fibroblasts and pulmonary artery smooth muscle cells, the most potent glycopolymer 18 (Lac-high) caused a decrease in the expression of markers of tissue remodeling in pulmonary hypertension. The glycopolymers were shown to penetrate into the cells. In a biodistribution and pharmacokinetics study in rats, the glycopolymers accumulated in heart and lung tissues, which are most affected by pulmonary hypertension.

Pilot Study Investigating Brain Natriuretic Peptide, Troponin, Galectin-3, and miRNA-126a-5p as Biomarkers of Persistent Pulmonary Hypertension in Neonates with Hypoxic-Ischemic Injury Receiving Therapeutic Hypothermia

OBJECTIVE

 The objective was to evaluate the utility of brain natriuretic peptide (BNP), troponin, galectin-3 (Gal-3), and microRNA (miRNA)-126a-5p as screening biomarkers for persistent pulmonary hypertension of the newborn (PPHN) by comparing expression in serum of infants with hypoxic-ischemic injury that develop PPHN to those that do not.

STUDY DESIGN

 This was a prospective, observational pilot study including neonates with hypoxic-ischemic injury undergoing therapeutic hypothermia (TH) at two regional perinatal medical centers. PPHN in this population was diagnosed clinically and confirmed by echocardiogram. Serial measurements of biomarkers were performed from 6 to 96 hours post-TH initiation in 40 patients.

RESULTS

 Of 40 infants in the study, 10 (25%) developed PPHN and 30 (75%) did not. Baseline demographics and hemodynamics were similar between the groups. Patients with PPHN had a significantly higher need for vasopressors compared with patients without PPHN (70 vs. 27%, p = 0.007). Mean serum BNP and troponin levels were significantly higher in the PPHN group peaking at 12 to 24 hours and decreasing following PPHN treatment initiation. miRNA-126a-5p expression was increased in patients with PPHN compared with patients without, with statistical significance detected at 12 hours (p = 0.005) and 96 hours (p = 0.01). Mean circulating Gal-3 levels were not statistically different between the two groups; however, Gal-3 was elevated in all patients with hypoxic-ischemic injury on TH compared with healthy infants from prior studies.

CONCLUSION

 BNP and troponin are readily available, low-cost biomarkers that showed significant serial elevations in the PPHN group of the study and, thus, may have value in screening for PPHN in the setting of hypoxic-ischemic encephalopathy (HIE). Gal-3 was elevated in all patients with HIE and may be a useful biomarker of hypoxic injury in infants being evaluated for TH. Elevations in miRNA-126a-5p were not consistently seen in this study. Larger studies are required to establish an association between PPHN and these biomarkers in patients with and without HIE.

KEY POINTS

· Serum biomarkers of persistent pulmonary hypertension of the newborn. · Serum biomarkers of hypoxic-ischemic injury.

Precision Hypertension

Hypertension affects >1 billion people worldwide. Complications of hypertension include stroke, renal failure, cardiac hypertrophy, myocardial infarction, and cardiac failure. Despite the development of various antihypertensive drugs, the number of people with uncontrolled hypertension continues to rise. While the lack of compliance associated with frequent side effects to medication is a contributory issue, there has been a failure to consider the diverse nature of hypertensive populations. Instead, we propose that hypertension can only be truly managed by precision. A precision medicine approach would consider each patient's unique factors. In this review, we discuss the progress toward precision medicine for hypertension with more predictiveness and individualization of treatment. We will highlight the advances in data science, omics (genomics, metabolomics, proteomics, etc), artificial intelligence, gene therapy, and gene editing and their application to precision hypertension.

RNA Therapeutics for the Cardiovascular System

RNA therapeutics hold significant promise in the treatment of cardiovascular diseases. RNAs are biologically diverse and functionally specific and can be used for gain- or loss-of-function purposes. The effectiveness of mRNA-based vaccines in the recent COVID-19 pandemic has undoubtedly proven the benefits of an RNA-based approach. RNA-based therapies are becoming more common as a treatment modality for cardiovascular disease. This is most evident in hypertension where several small interfering RNA-based drugs have proven to be effective in managing high blood pressure in several clinical trials. As befits a rapidly burgeoning field, there is significant interest in other classes of RNA. Revascularization of the infarcted heart through an mRNA drug is under clinical investigation. mRNA technology may provide the platform for the expression of paracrine factors for myocardial protection and regeneration. Emergent technologies on the basis of microRNAs and gene editing are tackling complex diseases in a novel fashion. RNA-based gene editing offers hope of permanent cures for monogenic cardiovascular diseases, and long-term control of complex diseases such as essential hypertension, as well. Likewise, microRNAs are proving effective in regenerating cardiac muscle. The aim of this review is to provide an overview of the current landscape of RNA-based therapies for the treatment of cardiovascular disease. The review describes the large number of RNA molecules that exist with a discussion of the clinical development of each RNA type. In addition, the review also presents a number of avenues for future development.

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

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

Cannabidiol alleviates right ventricular fibrosis by inhibiting the transforming growth factor β pathway in monocrotaline-induced pulmonary hypertension in rats

Cannabidiol (CBD) is a non-intoxicating compound of Cannabis with anti-fibrotic properties. Pulmonary hypertension (PH) is a disease that can lead to right ventricular (RV) failure and premature death. There is evidence that CBD reduces monocrotaline (MCT)-induced PH, including reducing right ventricular systolic pressure (RVSP), vasorelaxant effect on pulmonary arteries, and decreasing expression of profibrotic markers in the lungs. The aim of our study was to investigate the effect of chronic administration of CBD (10 mg/kg daily for 21 days) on profibrotic parameters in the RVs of MCT-induced PH rats. In MCT-induced PH, we found an increase in profibrotic parameters and parameters related to RV dysfunction, i.e. plasma pro-B-type natriuretic peptide (NT-proBNP), cardiomyocyte width, interstitial and perivascular fibrosis area, amount of fibroblasts and fibronectin, as well as overexpression of the transforming growth of factor β1 (TGF-β1), galectin-3 (Gal-3), suppressor of mothers against decapentaplegic 2 (SMAD2), phosphorylated SMAD2 (pSMAD2) and alpha-smooth muscle actin (α-SMA). In contrast, vascular endothelial cadherin (VE-cadherin) levels were decreased in the RVs of MCT-induced PH rats. Administration of CBD reduced the amount of plasma NT-proBNP, the width of cardiomyocytes, the amount of fibrosis area, fibronectin and fibroblast expression, as well as decreased the expression of TGF-β1, Gal-3, SMAD2, pSMAD2, and increased the level of VE-cadherin. Overall, CBD has been found to have the anti-fibrotic potential in MCT-induced PH. As such, CBD may act as an adjuvant therapy for PH, however, further detailed investigations are recommended to confirm our promising results.

Smooth Muscle Cell Phenotypic Switch Induced by Traditional Cigarette Smoke Condensate: A Holistic Overview

Cigarette smoke (CS) is a risk factor for inflammatory diseases, such as atherosclerosis. CS condensate (CSC) contains lipophilic components that may represent a systemic cardiac risk factor. To better understand CSC effects, we incubated mouse and human aortic smooth muscle cells (SMCs) with CSC. We evaluated specific markers for contractile [i.e., actin, aortic smooth muscle (ACTA2), calponin-1 (CNN1), the Kruppel-like factor 4 (KLF4), and myocardin (MYOCD) genes] and inflammatory [i.e., IL-1β, and IL-6, IL-8, and galectin-3 (LGALS-3) genes] phenotypes. CSC increased the expression of inflammatory markers and reduced the contractile ones in both cell types, with KLF4 modulating the SMC phenotypic switch. Next, we performed a mass spectrometry-based differential proteomic approach on human SMCs and could show 11 proteins were significantly affected by exposition to CSC (FC ≥ 2.7, p ≤ 0.05). These proteins are active in signaling pathways related to expression of pro-inflammatory cytokines and IFN, inflammasome assembly and activation, cytoskeleton regulation and SMC contraction, mitochondrial integrity and cellular response to oxidative stress, proteostasis control via ubiquitination, and cell proliferation and epithelial-to-mesenchymal transition. Through specific bioinformatics resources, we showed their tight functional correlation in a close interaction niche mainly orchestrated by the interferon-induced double-stranded RNA-activated protein kinase (alternative name: protein kinase RNA-activated; PKR) (EIF2AK2/PKR). Finally, by combining gene expression and protein abundance data we obtained a hybrid network showing reciprocal integration of the CSC-deregulated factors and indicating KLF4 and PKR as the most relevant factors.

Cannabidiol inhibits lung proliferation in monocrotaline-induced pulmonary hypertension in rats

Cannabidiol (CBD) is a safe and well-tolerated plant-derived drug with anti-proliferative properties. Pulmonary hypertension (PH) is a rapidly progressive and still incurable disease. CBD diminishes monocrotaline (MCT)-induced PH, including reduced right ventricular systolic pressure, pulmonary vascular hypertrophy, and right ventricular remodeling. The aim of our study was to investigate the effect of chronic administration of CBD (10 mg/kg once daily for 21 days) on selected remodeling parameters in the lung of MCT-induced PH rats. In MCT-induced PH, we found an increase in profibrotic parameters, e.g., transforming growth factor β1 (TGF-β1), galectin-3 (Gal-3), procollagen I, collagen I, C-propeptide, matrix metalloproteinase 9 (MMP-9) and an increased number of mast cells. In our study, we observed that the TGF-β1, Gal-3, procollagen I, collagen I, C-propeptide, and mast cell levels in lung tissue were decreased after CBD administration to MCT-treated rats. In summary, CBD treatment has an anti-proliferative effect on MCT-induced PH. Given the beneficial multidirectional effects of CBD on PH, we believe that CBD can be used as an adjuvant PH therapy, but this argument needs to be confirmed by clinical trials.

A placenta-on-a-chip model to determine the regulation of FKBPL and galectin-3 in preeclampsia

Preeclampsia is a pregnancy-specific cardiovascular disorder, involving significant maternal endothelial dysfunction. Although inappropriate placentation due to aberrant angiogenesis, inflammation and shallow trophoblast invasion are the root causes of preeclampsia, pathogenic mechanisms are poorly understood, particularly in early pregnancy. Here, we first confirm the abnormal expression of important vascular and inflammatory proteins, FK506-binding protein-like (FKBPL) and galectin-3 (Gal-3), in human plasma and placental tissues from women with preeclampsia and normotensive controls. We then employ a three-dimensional microfluidic placental model incorporating human umbilical vein endothelial cells (HUVECs) and a first trimester trophoblast cell line (ACH-3P) to investigate FKBPL and Gal-3 signaling in inflammatory conditions. In human samples, both circulating (n = 17 controls; n = 30 preeclampsia) and placental (n ≥ 6) FKBPL and Gal-3 levels were increased in preeclampsia compared to controls (plasma: FKBPL, p < 0.0001; Gal-3, p < 0.01; placenta: FKBPL, p < 0.05; Gal-3, p < 0.01), indicative of vascular dysfunction in preeclampsia. In our placenta-on-a-chip model, we show that endothelial cells are critical for trophoblast-mediated migration and that trophoblasts effectively remodel endothelial vascular networks. Inflammatory cytokine tumour necrosis factor-α (10 ng/mL) modulates both FKBPL and Gal-3 signaling in conjunction with trophoblast migration and impairs vascular network formation (p < 0.005). Our placenta-on-a-chip recapitulates aspects of inappropriate placental development and vascular dysfunction in preeclampsia.

Chimeric galectin-3 and collagens: Biomarkers and potential therapeutic targets in fibroproliferative diseases

Fibrosis, stiffening and scarring of an organ/tissue due to genetic abnormalities, environmental factors, infection, and/or injury, is responsible for > 40% of all deaths in the industrialized world, and to date, there is no cure for it despite extensive research and numerous clinical trials. Several biomarkers have been identified, but no effective therapeutic targets are available. Human galectin-3 is a chimeric gene product formed by the fusion of the internal domain of the collagen alpha gene [N-terminal domain (ND)] at the 5'-end of galectin-1 [C-terminal domain (CRD)] that appeared during evolution together with vertebrates. Due to the overlapping structural similarities between collagen and galectin-3 and their shared susceptibility to cleavage by matrix metalloproteases to generate circulating collagen-like peptides, this review will discuss present knowledge on the role of collagen and galectin-3 as biomarkers of fibrosis. We will also highlight the need for transformative approaches targeting both the ND and CRD domains of galectin-3, since glycoconjugate binding by the CRD is triggered by ND-mediated oligomerization and the therapies targeted only at the CRD have so far achieved limited success.

Prognostic value of galectin-3 and right ventricular function for long-term mortality in heart failure patients treated with cardiac resynchronization therapy

Recently, associations between the biomarker galectin-3 and numerous pathological processes involved in heart failure (HF) and right ventricular (RV) function have been observed. We aimed to assess the long-term prognostic ability of galectin-3 and RV function parameters for all-cause mortality in HF patients treated with cardiac resynchronization therapy (CRT). We prospectively studied 63 symptomatic HF patients with a left ventricular (LV) ejection fraction (EF) ≤ 35%. The median serum galectin-3 concentration was 13.4 ng/mL (IQR 11.05, 17.15). A detailed assessment of LV and RV geometry and function was performed with echocardiography. CRT defibrillator implantation was achieved in all patients without major complications. The follow-up lasted 5 years. In the multivariable Cox regression model, independent predictors for all-cause mortality were log baseline galectin-3 and baseline RV function expressed as tricuspid annular plane systolic excursion with HR 2.96 (p = 0.037) and HR 0.88 (p = 0.023), respectively. Analysis of subgroups defined by galectin-3 concentration and CRT response showed that patients with high baseline galectin-3 concentrations and a lack of response to CRT had a significantly lower probability of survival. In our patient cohort, the baseline galectin-3 concentration and RV function were independent predictors of long-term all-cause mortality in HFrEF patients following CRT implantation.

CRISPR/Cas9 Mediated Deletion of the Angiotensinogen Gene Reduces Hypertension: A Potential for Cure?

[Figure: see text].

Endothelial-to-Mesenchymal Transition in Pulmonary Arterial Hypertension

Endothelial-to-mesenchymal transition (EndMT) is a process that encompasses extensive transcriptional reprogramming of activated endothelial cells leading to a shift toward mesenchymal cellular phenotypes and functional responses. Initially observed in the context of embryonic development, in the last few decades EndMT is increasingly recognized as a process that contributes to a variety of pathologies in the adult organism. Within the settings of cardiovascular biology, EndMT plays a role in various diseases, including atherosclerosis, heart valvular disease, cardiac fibrosis, and myocardial infarction. EndMT is also being progressively implicated in development and progression of pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH). This review covers the current knowledge about EndMT in PH and PAH, and provides comprehensive overview of seminal discoveries. Topics covered include evidence linking EndMT to factors associated with PAH development, including hypoxia responses, inflammation, dysregulation of bone-morphogenetic protein receptor 2 (BMPR2), and redox signaling. This review amalgamates these discoveries into potential insights for the identification of underlying mechanisms driving EndMT in PH and PAH, and discusses future directions for EndMT-based therapeutic strategies in disease management.

Activation of AMPK inhibits Galectin-3-induced pulmonary artery smooth muscle cells proliferation by upregulating hippo signaling effector YAP

Galectin-3(Gal-3) is an effective regulator in the pathological process of pulmonary arterial hypertension (PAH). However, the detailed mechanisms underlying Gal-3 contribution to PAH are not yet entirely clear. The aim of the present study was to explore these issues. Proliferation of rat pulmonary arterial smooth muscle cells (PASMCs) was determined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Small interfering RNA (siRNA) was applied to silence the expression of yes-associated protein (YAP) and Forkhead box M1 (FOXM1). The protein expression and phosphorylation were measured by immunoblotting. The subcellular location of YAP was determined using immunoblotting and immunofluorescence. Gal-3-stimulated PASMCs proliferation in a time- and dose-dependent manner, this was accompanied with, YAP upregulation, dephosphorylation, and nucleus translocation. Gal-3 further increased FOXM1 and cyclinD1 expression via YAP activation. Interfering YAP/FOXM1 axis suppressed Gal-3-induced PASMCs proliferation. Activation of AMPK also inhibited Gal-3-triggered cells proliferation by targeting YAP/FOXM1/cyclinD1 pathway. Gal-3 induced PASMCs proliferation by regulating YAP/FOXM1/cyclinD1 signaling cascade, and activation of AMPK targeted on this axis and suppressed Gal-3-stimulated PASMCs proliferation. Our study provides novel therapeutic targets for prevention and treatment of PAH.

Galectin-3 Promotes ROS, Inflammation, and Vascular Fibrosis in Pulmonary Arterial Hypertension

Pulmonary Arterial Hypertension (PAH) is a progressive vascular disease arising from the narrowing of pulmonary arteries (PA) resulting in high pulmonary arterial blood pressure and ultimately right ventricular (RV) failure. A defining characteristic of PAH is the excessive remodeling of PA that includes increased proliferation, inflammation, and fibrosis. There is no cure for PAH nor interventions that effectively impede or reverse PA remodeling, and research over the past several decades has sought to identify novel molecular mechanisms of therapeutic benefit. Galectin-3 (Gal-3; Mac-2) is a carbohydrate-binding lectin that is remarkable for its chimeric structure, comprised of an N-terminal oligomerization domain and a C-terminal carbohydrate-recognition domain. Gal-3 is a regulator of changes in cell behavior that contribute to aberrant PA remodeling including cell proliferation, inflammation, and fibrosis, but its role in PAH is poorly understood. Herein, we summarize the recent literature on the role of Gal-3 in the development of PAH and provide experimental evidence supporting the ability of Gal-3 to influence reactive oxygen species (ROS) production, NOX enzyme expression, inflammation, and fibrosis, which contributes to PA remodeling. Finally, we address the clinical significance of Gal-3 as a target in the development of therapeutic agents as a treatment for PAH.

Galectin-3 is related to right ventricular dysfunction in heart failure patients with reduced ejection fraction and may affect exercise capacity

Galectin-3 is a biomarker of fibrosis, inflammation and oxidative stress, and its role in heart remodelling and exercise intolerance has not been conclusively proven in heart failure (HF) patients with reduced ejection fraction (rEF). We prospectively assessed 67 consecutive patients with symptomatic HF and left ventricular (LV) EF ≤ 35% during optimal medical therapy, with a mean serum galectin-3 concentration of 15.3 ± 6.4 and a median of 13.5 ng/mL. The group with galectin-3 concentrations greater than or equal to the median had significantly worse right ventricular (RV) systolic function parameters (s′, TAPSE), higher pulmonary artery systolic pressure, more advanced tricuspid regurgitation and lower RV-to-pulmonary circulation coupling index, while no significant differences were found in LV parameters. Moreover, this group achieved significantly lower parameters in cardiopulmonary exercise testing. Significant negative correlations were found between galectin-3 concentration and RV parameters and exercise capacity parameters and have persisted after adjustment for glomerular filtration rate, but not all of them have persisted after adjustment for NT-proBNP. Multivariate regression analysis revealed that TAPSE (β coefficient: − 0.605; p < 0.001) and heart rate at peak exercise (β coefficient: − 0.98; p = 0.009) were independently related to galectin-3 concentration. Elevated galectin-3 concentration in patients with HFrEF might indicate concomitant RV dysfunction and exercise intolerance.

Hyperinflammation and Fibrosis in Severe COVID-19 Patients: Galectin-3, a Target Molecule to Consider

COVID-19 disease have become so far the most important sanitary crisis in the XXI century. In light of the events, any clinical resource should be considered to alleviate this crisis. Severe COVID-19 cases present a so-called cytokine storm as the most life-threatening symptom accompanied by lung fibrosis. Galectin-3 has been widely described as regulator of both processes. Hereby, we present compelling evidences on the potential role of galectin-3 in COVID-19 in the regulation of the inflammatory response, fibrosis and infection progression. Moreover, we provide a strong rationale of the utility of measuring plasma galectin-3 as a prognosis biomarker for COVID-19 patients and propose that inhibition of galectin-3 represents a feasible and promising new therapeutical approach.

Galectin-3 mediates pulmonary vascular endothelial cell dynamics via TRPC1/4 under acute hypoxia

Galectin-3 (Gal-3) has been implicated in various biological functions, yet little is known about its role in regulating the dynamics of pulmonary vascular endothelial cells. Gal-3 was shown to be increased in hypoxic model rats by sequencing analysis. We exposed pulmonary vessel endothelial cells (PVECs) to hypoxia or Gal-3 stimulation, following which cell apoptosis and autophagy were measured with the relevant methods. The results demonstrated that hypoxia elevated nuclear factor-κB (NF-κB) activity and Gal-3 expression. Gla-3 decreased the expression of Bcl-2, Alix, Beclin-1, Atg5, and LC3A/B. The messenger RNA and protein levels of transient receptor potential channel 1/4 (TRPC1/4) and calpain were reduced after Gal-3 treatment. Gal-3 also activated protein kinase B/glycogen synthase kinase-3 β/mammalian target of rapamycin signaling pathways in PVECs. These results suggest that a hypoxia-mediated increase in Gal-3 promotes apoptosis and inhibits autophagy by inhibiting the TRPC1/4 pathway and activating the protein kinase B/glycogen synthase kinase-3 β/mammalian target of rapamycin signaling pathway in PVECs. Furthermore, these results may provide us with a new direction to explore the pathogenesis of pulmonary artery hypertension.

Galectin-3: A Harbinger of Reactive Oxygen Species, Fibrosis, and Inflammation in Pulmonary Arterial Hypertension

Significance: Pulmonary arterial hypertension (PAH) is a progressive disease arising from the narrowing of pulmonary arteries (PAs) resulting in high pulmonary arterial blood pressure and ultimately right ventricle (RV) failure. A defining characteristic of PAH is the excessive and unrelenting inward remodeling of PAs that includes increased proliferation, inflammation, and fibrosis. Critical Issues: There is no cure for PAH nor interventions that effectively arrest or reverse PA remodeling, and intensive research over the past several decades has sought to identify novel molecular mechanisms of therapeutic value. Recent Advances: Galectin-3 (Gal-3) is a carbohydrate-binding lectin remarkable for its chimeric structure, composed of an N-terminal oligomerization domain and a C-terminal carbohydrate-recognition domain. Gal-3 has been identified as a regulator of numerous changes in cell behavior that contributes to aberrant PA remodeling, including cell proliferation, inflammation, and fibrosis, but its role in PAH has remained poorly understood until recently. In contrast, pathological roles for Gal-3 have been proposed in cancer and inflammatory and fibroproliferative disorders, such as pulmonary vascular and cardiac fibrosis. Herein, we summarize the recent literature on the role of Gal-3 in the development of PAH. We provide experimental evidence supporting the ability of Gal-3 to influence reactive oxygen species production, NADPH oxidase enzyme expression, and redox signaling, which have been shown to contribute to both vascular remodeling and increased pulmonary arterial pressure. Future Directions: While several preclinical studies suggest that Gal-3 promotes hypertensive pulmonary vascular remodeling, the clinical significance of Gal-3 in human PAH remains to be established. Antioxid. Redox Signal. 00, 000-000.

Galectin-3 Mediates Endothelial-to-Mesenchymal Transition in Pulmonary Arterial Hypertension

Galectin-3 (Gal-3) is highly expressed in fibrotic tissue related to diverse etiologies. endothelial-to-mesenchymal transition (EndoMT), A less well studied phenomenon serves as a critical process in pulmonary vascular remodeling associated with the development of pulmonary arterial hypertension (PAH). EndoMT is hypothesized to contribute to the over-proliferation of αSMA positive cells. We aim to investigate the potential role of Gal-3 in regulating EndoMT in PAH. We observed an upregulation in both Gal-3 and αSMA expression in the monocrotaline (MCT) and Hypoxia PAH model, accompanied with intimal thickening. For more profound vascular remodeling and endothelial layer lesion in former model, we employed Gal-3 knockdown and overexpression lentivirus methodology to the MCT rats to determine the mechanisms underlying abnormal endothelial cell transition in PAH. PAH was evaluated according to right ventricular systolic pressure, right heart hypertrophy and pulmonary artery remodeling. A reduction in Gal-3 was protective against the development of PAH, while Gal-3 upregulation aggravated pulmonary vascular occlusion. In addition, Gal-3 deficiency suppressed pulmonary vascular cell proliferation and macrophage infiltration. Finally, we revealed that in endothelial cells treated with tumor necrosis factor α and hypoxia (representing an in vitro model of PAH), inhibition of Gal-3 by siRNA was able to abolish the associated upregulation of αSMA. These observations suggesting Gal-3 serves as a critical mediator in PAH by regulating EndoMT. Inhibition of Gal-3 may represent a novel therapeutic target for PAH treatment.

Galectin-3 aggravates pulmonary arterial hypertension via immunomodulation in congenital heart disease

Pulmonary arterial hypertension (PAH) is reported to contribute to right ventricular failure and death. PAH of variable degrees is often related to congenital heart disease (CHD). Galectin-3 (Gal-3) has been proven to be of great importance in PAH and CHD. Therefore, we investigated the specific mechanism of Gal-3 in CHD-PAH. Patients with CHD-PAH were enrolled to detect the changes of T-cell subsets, cytokine levels, and other related inflammatory cells in the plasma and to assess the Gal-3 levels in the serum. Next, CHD-PAH mouse models were established and treated with restored or depleted Gal-3 to evaluate the systolic pulmonary artery pressure (sPAP) and right ventricular hypertrophy index (RVHI), to determine levels of IL-4, IL-5, IL-13, AKT and p-AKT along with proliferation of pulmonary artery smooth muscle cells (PASMCs). Finally, we explored the effects of adoptive transfer of CD4⁺T cells on CHD-PAH in mice with Gal-3 knockdown to further investigate the role of Gal-3 in vivo. Initially, Gal-3 was up-regulated in patients with CHD-PAH. Subsequently, it was demonstrated that restored Gal-3 increased sPAP and RVHI, and promoted proliferation of PASMCs by activating the immune response with elevated levels of IL-4, IL-5, IL-13 and p-AKT. Finally, adoptive transfer of CD4⁺T cells promoted CD4⁺T cell perivascular infiltration and the progression of CHD-PAH in mice with Gal-3 knockdown. Collectively, the current study suggests a facilitating role of Gal-3 in pulmonary artery remodeling and progression of CHD-PAH via activation of Th2.

Galectin-3 is expressed in vascular smooth muscle cells and promotes pulmonary hypertension through changes in proliferation, apoptosis, and fibrosis

A defining characteristic of pulmonary hypertension (PH) is the extensive remodeling of pulmonary arteries (PAs), which results in progressive increases in vascular resistance and stiffness and eventual failure of the right ventricle. There is no cure for PH and identification of novel molecular mechanisms that underlie increased proliferation, reduced apoptosis, and excessive extracellular matrix production in pulmonary artery smooth muscle cells (PASMCs) is a vital objective. Galectin-3 (Gal-3) is a chimeric lectin and potent driver of many aspects of fibrosis, but its role in regulating PASMC behavior in PH remains poorly understood. Herein, we evaluated the importance of increased Gal-3 expression and signaling on PA vascular remodeling and cardiopulmonary function in experimental models of PH. Gal-3 expression was quantified by qRT-PCR, immunoblotting, and immunofluorescence imaging, and its functional role was assessed by specific Gal-3 inhibitors and CRISPR/Cas9-mediated knockout of Gal-3 in the rat. In rat models of PH, we observed increased Gal-3 expression in PASMCs, which stimulated migration and resistance to apoptosis, whereas silencing or genetic deletion reduced cellular migration and PA fibrosis and increased apoptosis. Gal-3 inhibitors attenuated and reversed PA remodeling and fibrosis, as well as hemodynamic indices in monocrotaline (MCT)-treated rats in vivo. These results were supported by genetic deletion of Gal-3 in both MCT and Sugen Hypoxia rat models. In conclusion, our results suggest that elevated Gal-3 levels contribute to inappropriate PA remodeling in PH by enhancing multiple profibrotic mechanisms. Therapeutic strategies targeting Gal-3 may be of benefit in the treatment of PH.

A potential biomarker hsa-miR-200a-5p distinguishing between benign thyroid tumors with papillary hyperplasia and papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common endocrine cancer with a significantly increase of the incidence recently. Several cytokines, such as thyroid peroxidase (TPO), cluster of differentiation 56 (CD56), Galectin-3, mesothelial cell (MC), cytokeratin 19 (CK19) and BRAF (B-raf) were recommended to be tested by immunohistochemistry (IHC) for a definitive diagnosis, but were still limited in clinical use because of their relative lower sensitivity and specificity. MicroRNA (miRNA), as a new molecular biomarkers, however, has not been reported yet so far. To address this, hsa-miR-200a-5p, a miRNA, was selected and detected in PTC patients by in situ hybrization with benign thyroid tumor with papillary hyperplasia as a control, and the differential expression of hsa-miR-200a-5p between fresh PTC tissues and control was detected by qRT-PCR. Expressive levels of cytokines of TPO, CD56, Galectin-3, MC, CK19 and B-raf were also detected by immunohistochemistry. The correlation was analyzed by SPSS software using Spearman methods. As expected, the hsa-miR-200a-5p expressive level was significantly increased in PTC patients, compared to that of control, and was consistent with that of TPO, CD56, Galectin-3, MC, CK19 and B-raf. In addition, expression of hsa-miR-200a-5p showed negative correlation to that of TPO (rs = - 0.734; **: P < 0.01) and CD56 (rs = - 0.570; **: P < 0.01), but positive correlation to that of Galectin-3 (rs = 0.601; **: P < 0.01), MC (rs = 0.508; **: P < 0.01), CK19 (rs = 0.712; **: P < 0.01) and B-raf (rs = 0.378; **: P < 0.01). PTC and papillary benign thyroid papillary hyperplasia are difficult to distinguish in morphology, so requiring immunohistochemistry to further differentiate the diagnosis, however, for the existing clinical common diagnostic marker for immunohistochemistry, the sensitivity and accuracy are low, it is easy to miss diagnosis. Therefore, there is an urgent need for a rapid and sensitive molecular marker. So miR-200a-5p can be used to assist in the diagnosis of PTC at the molecular level, and as a biomarker, can be effectively used to distinguish between PTC and benign thyroid tumor with papillary hyperplasia.

Galectin-3 mediates pulmonary vascular remodeling in hypoxia-induced pulmonary arterial hypertension

Pulmonary vascular adventitia serves as a key regulator of pulmonary vascular remodeling in the pathogenesis of pulmonary arterial hypertension (PAH). Excessive proliferation and differentiation of pulmonary adventitial fibroblasts (PAFs) are proven to be crucial in the pathogenesis of PAH. Galectin-3 (Gal-3) is known as a key fibroblasts activating factor which is involved in the fibrogenesis of several diseases, such as pulmonary fibrosis, vascular fibrosis, and heart failure. Therefore, we seek to investigate the potential role of Gal-3 in regulating PAF cells in the pathogenesis of PAH. Gal-3 plasma concentration was significantly higher in PAH patients. Gal-3 was upregulated in pulmonary artery adventitia of hypoxia-induced PAH rats. Inhibition of Gal-3 with N-Acetyl-D-lactosamine (N-Lac) ameliorated PAH and pulmonary vascular remodeling. Gal-3 can stimulate the proliferation, differentiation, and collagen synthesis of PAFs, which was reversed by N-Lac. Transforming growth factor β1 increased Gal-3 expression in PAFs, whereas N-Lac significantly suppressed transforming growth factor β1-induced proliferation, differentiation, and collagen synthesis of PAFs. Gal-3 serves as a critical regulator in the pathogenesis of PAH by regulating the proliferation, differentiation, and extracellular matrix deposition synthesis of PAFs. Inhibition of Gal-3 may represent a novel therapeutic target for PAH treatment.

RNAi therapy to the wall of arteries and veins: anatomical, physiologic, and pharmacological considerations

Background

Cardiovascular disease remains a major health care challenge. The knowledge about the underlying mechanisms of the respective vascular disease etiologies has greatly expanded over the last decades. This includes the contribution of microRNAs, endogenous non-coding RNA molecules, known to vastly influence gene expression. In addition, short interference RNA has been established as a mechanism to temporarily affect gene expression. This review discusses challenges relating to the design of a RNA interference therapy strategy for the modulation of vascular disease. Despite advances in medical and surgical therapies, atherosclerosis (ATH), aortic aneurysms (AA) are still associated with high morbidity and mortality. In addition, intimal hyperplasia (IH) remains a leading cause of late vein and prosthetic bypass graft failure. Pathomechanisms of all three entities include activation of endothelial cells (EC) and dedifferentiation of vascular smooth muscle cells (VSMC). RNA interference represents a promising technology that may be utilized to silence genes contributing to ATH, AA or IH. Successful RNAi delivery to the vessel wall faces multiple obstacles. These include the challenge of cell specific, targeted delivery of RNAi, anatomical barriers such as basal membrane, elastic laminae in arterial walls, multiple layers of VSMC, as well as adventitial tissues. Another major decision point is the route of delivery and potential methods of transfection. A plethora of transfection reagents and adjuncts have been described with varying efficacies and side effects. Timing and duration of RNAi therapy as well as target gene choice are further relevant aspects that need to be addressed in a temporo-spatial fashion.

Conclusions

While multiple preclinical studies reported encouraging results of RNAi delivery to the vascular wall, it remains to be seen if a single target can be sufficient to the achieve clinically desirable changes in the injured vascular wall in humans. It might be necessary to achieve simultaneous and/or sequential silencing of multiple, synergistically acting target genes. Some advances in cell specific RNAi delivery have been made, but a reliable vascular cell specific transfection strategy is still missing. Also, off-target effects of RNAi and unwanted effects of transfection agents on gene expression are challenges to be addressed. Close collaborative efforts between clinicians, geneticists, biologists, and chemical and medical engineers will be needed to provide tailored therapeutics for the various types of vascular diseases.