The role of TGFβ1 and LRG1 in cardiac remodelling and heart failure

Shared signaling pathways and comprehensive therapeutic approaches among diabetes complications

The growing global prevalence of diabetes mellitus (DM), along with its associated complications, continues to rise. When clinically detected most DM complications are irreversible. It is therefore crucial to detect and address these complications early and systematically in order to improve patient care and outcomes. The current clinical practice often prioritizes DM complications by addressing one complication while overlooking others that could occur. It is proposed that the commonly targeted cell types including vascular cells, immune cells, glial cells, and fibroblasts that mediate DM complications, might share early responses to diabetes. In addition, the impact of one complication could be influenced by other complications. Recognizing and focusing on the shared early responses among DM complications, and the impacted cellular constituents, will allow to simultaneously address all DM-related complications and limit adverse treatment impacts. This review explores the current understanding of shared pathological signaling mechanisms among DM complications and recognizes new concepts that will benefit from further investigation in both basic and clinical settings. The ultimate goal is to develop more comprehensive treatment strategies, which effectively impact DM complications in multiple organs and improve patient care and outcomes.

Pioglitazone as a potential modulator in autoimmune diseases: a review on its effects in systemic lupus erythematosus, psoriasis, inflammatory bowel disease, and multiple sclerosis

INTRODUCTION

Current medications for autoimmune disorders often induce broad-ranging side effects, prompting a growing interest in therapies with more specific immune system modulation. Pioglitazone, known for its anti-diabetic properties, is increasingly recognized for significant immunomodulatory potential. Beyond its traditional use in diabetes management, pioglitazone emerges as a promising therapeutic candidate for autoimmune disorders.

AREAS COVERED

This comprehensive review explores pioglitazone's impact on four prominent autoimmune conditions: systemic lupus erythematosus, psoriasis, inflammatory bowel disease, and multiple sclerosis. We focus on pioglitazone's diverse effects on immune cells and cytokines in these diseases, highlighting its potential as a valuable therapeutic option for autoimmune diseases. Here we have reviewed the latest and most current research literature available on PubMed, based on research published in the last 15 years.

EXPERT OPINION

Pioglitazone as an immunomodulatory agent can regulate T cell differentiation, inhibit inflammatory cytokines, and promote anti-inflammatory macrophages. While further clinical studies are needed to fully understand its mechanisms and optimize treatment strategies, pioglitazone represents a potential therapeutic approach to improve outcomes for patients with these challenging autoimmune conditions. The future of autoimmune disease research may involve personalized treatment approaches, and collaborative efforts to improve patient quality of life.

Evaluating Biomarkers as Tools for Early Detection and Prognosis of Heart Failure: A Comprehensive Review

There is a high prevalence of heart failure (HF) worldwide, which has significant consequences for healthcare costs, patient death and quality of life. Therefore, there has been much focus on finding and using biomarkers for early diagnosis, prognostication and therapy of HF. This overview of the research presents a thorough examination of the current state of HF biomarkers and their many uses. Their function in diagnosing HF, gauging its severity and monitoring its response to therapy are all discussed. Particularly promising in HF diagnosis and risk stratification are the cardiac-specific biomarkers, B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide. Markers of oxidative stress, extracellular matrix, renal function, inflammation and cardiac peptides have shown promise in evaluating HF severity and prognosis. MicroRNAs and insulin-like growth factor are two emerging biomarkers that have shown potential in helping with HF diagnosis and prognosis.

Plasma leucine-rich α-2 glycoprotein 1 in ST-elevation myocardial infarction: vertical variation, correlation with T helper 17/regulatory T ratio, and predictive value on major adverse cardiovascular events

Objective

Leucine-rich α-2 glycoprotein 1 (LRG1) promotes inflammation and myocardial injury, but its clinical role in ST-elevation myocardial infarction (STEMI) is rarely disclosed. Herein, this prospective study aimed to explore the value of plasma LRG1 at different time points to predict major adverse cardiovascular event (MACE) risk in patients with STEMI.

Methods

In total, 209 patients with STEMI were enrolled for determining plasma LRG1 at admission and on day (D)1/D7/D30 after admission via enzyme-linked immunosorbent assay, as well as for determination of peripheral blood T helper 17 (Th17) cells and regulatory T (Treg) cells by flow cytometry. In addition, plasma LRG1 was obtained from 30 healthy controls at enrollment.

Results

LRG1 was increased in patients with STEMI at admission compared with healthy controls (P < 0.001). In patients with STEMI, LRG1 varied at different time points (P < 0.001), which elevated from admission to D1, and gradually declined thereafter. LRG1 at admission was positively associated with Th17 cells (P = 0.001) and Th17/Treg ratio (P = 0.014). LRG1 at admission (P = 0.013), D1 (P = 0.034), D7 (P = 0.001), and D30 (P = 0.010) were increased in patients with MACE compared with those without. LRG1 at D7 exhibited good ability to estimate MACE risk (area under curve = 0.750, 95% confidence interval = 0.641-0.858). LRG1 at admission > 60 μg/ml (P = 0.031) and D7 > 60 μg/ml (P = 0.018) were linked with increased accumulating MACE. Importantly, LRG1 at D7 > 60 μg/ml was independently correlated with increased MACE risk (hazard ratio = 5.216, P = 0.033).

Conclusion

Plasma LRG1 increases from admission to D1 and gradually declines until D30, which positively links with Th17 cells and MACE risk in patients with STEMI.

Increased level of serum leucine-rich-alpha-2-glycoprotein 1 in patients with clear cell renal cell carcinoma

BACKGROUND

Currently, no useful serum markers exist for clear cell renal cell carcinoma (ccRCC), making early detection challenging as diagnosis relies solely on imaging tests. Radiation exposure is also a concern due to multiple required CT examinations during treatment. Renal cell carcinoma (RCC) histological types include ccRCC and non-clear cell RCC (non-ccRCC); however, treatment response to medications varies which necessitates accurate differentiation between the two. Therefore, we aimed to identify a novel serum marker of RCC. Increased LRG1 expression in the serum has been demonstrated in multiple cancer types. However, the expression of LRG1 expression in the serum and cancer tissues of patients with RCC has not been reported. Since ccRCC is a hypervascular tumor and LRG1 is capable of accelerating angiogenesis, we hypothesized that the LRG1 levels may be related to ccRCC. Therefore, we examined LRG1 expression in sera from patients with RCC.

METHODS

Using an enzyme-linked immunosorbent assay, serum levels of leucine-rich-alpha-2-glycoprotein 1 (LRG1) were measured in 64 patients with ccRCC and 22 patients non-ccRCC who underwent radical or partial nephrectomy, as well as in 63 patients without cancer.

RESULTS

Median values of serum LRG1 and their inter-quartile ranges were 63.2 (42.8-94.2) µg/mL in ccRCC, 23.4 (17.7-29.6) µg/mL in non-ccRCC, and 36.0 (23.7-56.7) µg/mL in patients without cancer, respectively (ccRCC vs. non-ccRCC or patients without cancer: P < 0.001). C-reactive protein (CRP) levels (P = 0.002), anemia (P = 0.037), hypercalcemia (P = 0.023), and grade (P = 0.031) were independent predictors of serum LRG1 levels in ccRCC. To assess diagnostic performance, the area under the receiver operating characteristic curve of serum LRG1 was utilized to differentiate ccRCC from non-cancer and non-ccRCC, with values of 0.73 (95% CI, 0.64-0.82) and 0.91 (95% CI, 0.82-0.96), respectively.

CONCLUSIONS

LRG1 served as a serum marker associated with inflammation, indicated by CRP, anemia, hypercalcemia, and malignant potential in ccRCC. Clinically, serum LRG1 levels may assist in differentiating ccRCC from non-ccRCC with excellent diagnostic accuracy.

Leucine-Rich Alpha-2 Glycoprotein 1 Accumulates in Complicated Atherosclerosis and Promotes Calcification

Atherosclerosis is the primary cause of cardiovascular disease. The development of plaque complications, such as calcification and neo-angiogenesis, strongly impacts plaque stability and is a good predictor of mortality in patients with atherosclerosis. Despite well-known risk factors of plaque complications, such as diabetes mellitus and chronic kidney disease, the mechanisms involved are not fully understood. We and others have identified that the concentration of circulating leucine-rich α-2 glycoprotein 1 (LRG1) was increased in diabetic and chronic kidney disease patients. Using apolipoprotein E knockout mice (ApoE-/-) (fed with Western diet) that developed advanced atherosclerosis and using human carotid endarterectomy, we showed that LRG1 accumulated into an atherosclerotic plaque, preferentially in calcified areas. We then investigated the possible origin of LRG1 and its functions on vascular cells and found that LRG1 expression was specifically enhanced in endothelial cells via inflammatory mediators and not in vascular smooth muscle cells (VSMC). Moreover, we identified that LRG1 was able to induce calcification and SMAD1/5-signaling pathways in VSMC. In conclusion, our results identified for the first time that LRG1 is a direct contributor to vascular calcification and suggest a role of this molecule in the development of plaque complications in patients with atherosclerosis.

Exosome enriched leucine-rich alpha-2-glycoprotein-1 and extracellular matrix protein 1 proteins induce abnormal placental angiogenesis in pregnant mice

INTRODUCTION

Gestational Diabetes Mellitus (GDM) is characterized by a high risk of fetal macrosomia and placenta hypervascularization. Exosomes has been known participating in various physiological and pathological processes, including pro-angiogenic function. However, the effects of umbilical cord blood derived exosomes from cases of GDM (GDM-exo) on placental vascular network formation remain unclear.

METHODS

In the current study, we isolated and identified exosomes in umbilical cord blood from both normal (N-exo) and GDM pregnancies. Meanwhile, we investigated the effects of umbilical cord blood derived exosomes on placental angiogenesis both in vitro and in vivo.

RESULTS

Our data indicated that in a mouse model, the placenta and fetus weight were significantly higher in the ones administrated with GDM-exo when compared with N-exo. Meanwhile, GDM-exo significantly enhanced placental endothelial cells functions in both HUVEC and HPMEC endothelial cell models. Importantly, we explored two up-regulated proteins in GDM-exo, namely leucine-rich alpha-2-glycoprotein-1 (LRG1) and extracellular matrix protein 1 (ECM1) by proteome analysis, which performed largely pro-angiogenic function and probably resulted in hypervascularization in GDM placenta.

DISCUSSION

Thus, we proposed that abundant LRG1 and ECM1 enriched GDM-exo may take important roles in regulating pathological placental angiogenesis.

LRG1 Promotes ECM Integrity by Activating the TGF-β Signaling Pathway in Fibroblasts

Leucine-rich alpha-2-glycoprotein 1 (LRG1) mediates skin repair and fibrosis by stimulating the transforming growth factor-beta (TGF-β) signaling pathway. In the present study, we investigated the effect of LRG1 on extracellular matrix (ECM) integrity in fibroblasts, as well as on skin aging. The treatment of dermal fibroblasts with purified recombinant human LRG1 increased type I collagen secretion and decreased matrix metalloproteinase-1 secretion. Additionally, LRG1 promoted SMAD2/SMAD3 phosphorylation in a pattern similar to that of TGF-β1 treatment. An inhibitor of TGF-β receptor 1 abolished LRG1-induced SMAD2 phosphorylation. RNA sequencing identified "extracellular region", "extracellular space", and "extracellular matrix" as the main Gene Ontology terms in the differentially expressed genes of fibroblasts treated with or without LRG1. LRG1 increased TGF-β1 mRNA levels, suggesting that LRG1 partially transactivates the expression of TGF-β1. Furthermore, an increased expression of type I collagen was also observed in fibroblasts grown in three-dimensional cultures on a collagen gel mimicking the dermis. LRG1 mRNA and protein levels were significantly reduced in elderly human skin tissues with weakened ECM integrity compared to in young human skin tissues. Taken together, our results suggest that LRG1 could retard skin aging by activating the TGF-β signaling pathway, increasing ECM deposition while decreasing its degradation.

Leucine-Rich Alpha-2-Glycoprotein: A Novel Predictor of Diastolic Dysfunction

Leucine-rich α2-glycoprotein (LRG1) mediates cardiac fibrocyte activation. It is upregulated in inflammatory conditions, atherosclerosis, and fibrosis. Diastolic dysfunction (DD) is due to myocardial fibrosis. This cross-sectional study examined the relationship between LRG1 and DD. Patients with symptoms of chronic coronary ischemia were recruited. Patients with symptoms of overt heart failure, ejection fraction (EF) < 55%, impaired renal function, infection, and recent trauma were excluded from the study. Clinical parameters examined were SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) score, echocardiographic assessment, and LRG1 levels. Binary stepwise logistic regression was used to evaluate the association between LRG1 and DD. Receiver Operating Characteristic (ROC) analysis was used to determine optimal cut-off values and predictive performance of LRG1. A total of 94 patients were enrolled in the study, with 47 having a clinical diagnosis of DD. Plasma LRG1 was significantly (U = 417.00, p < 0.001) higher in the DD group (M = 14) compared to the No-DD group (M = 8) by Mann-Whitney U test. There were higher SYNTAX scores in the DD group (M = 24.5) compared with No-DD (M = 7). LRG1 had significant predictability of DD (OR = 1.32 (95% CI: 1.14-1.53)). The ROC showed an AUC = 0.89 (95% CI: 0.82-0.95). LRG1 had a 78% sensitivity (95% CI: 65.3-87.7) and 72.3% specificity (95% CI: 57.4-84.4) for predicting DD at a cut-off value of "9". In conclusion, we identified LRG1 as a novel independent predictor of DD. Further studies are warranted to validate the utility of LRG1 in predicting DD.

Association between Higher Circulating Leucine-Rich α-2 Glycoprotein 1 Concentrations and Specific Plasma Ceramides in Postmenopausal Women with Type 2 Diabetes

Background: Although ceramides are involved in the pathophysiology of cardiovascular disease and other inflammation-associated disorders, there is a paucity of data on the association between plasma ceramides and inflammatory biomarkers in type 2 diabetes mellitus (T2DM). Therefore, we explored whether there was an association between plasma leucine-rich α-2 glycoprotein 1 (LRG1) concentrations (i.e., a novel proinflammatory signaling molecule) and specific plasma ceramides in postmenopausal women with T2DM. Methods: We measured six previously identified plasma ceramides, which have been associated with increased cardiovascular risk [plasma Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/20:0), Cer(d18:1/22:0), Cer(d18:1/24:0) and Cer(d18:1/24:1)], amongst 99 Caucasian postmenopausal women with non-insulin-treated T2DM (mean age 72 ± 8 years, mean hemoglobin A1c 6.9 ± 0.7%), who consecutively attended our diabetes outpatient service during a 3-month period. Plasma ceramide and LRG1 concentrations were measured with a targeted liquid chromatography-tandem mass spectrometry assay and a Milliplex® MAP human cardiovascular disease magnetic bead kit, respectively. Results: In linear regression analyses, higher plasma LRG1 levels (1st tertile vs. 2nd and 3rd tertiles combined) were associated with higher levels of plasma Cer(d18:1/16:0) (standardized β coefficient: 0.289, p = 0.004), Cer(d18:1/18:0) (standardized β coefficient: 0.307, p = 0.002), Cer(d18:1/20:0) (standardized β coefficient: 0.261, p = 0.009) or Cer(d18:1/24:1) (standardized β coefficient: 0.343, p < 0.001). These associations remained significant even after adjusting for age, body mass index, systolic blood pressure, total cholesterol level, hemoglobin A1c, insulin resistance and statin use. Conclusions: The results of our pilot exploratory study suggest that higher plasma LRG1 concentration was associated with higher levels of specific high-risk plasma ceramide molecules in elderly postmenopausal women with metabolically well-controlled T2DM, even after adjusting for known cardiovascular risk factors and other potential confounding variables.

Association of gene polymorphisms in FBN1 and TGF-β signaling with the susceptibility and prognostic outcomes of Stanford type B aortic dissection

Background

This study is aimed at investigating the association of Fibrillin-1 (FBN1) and transforming growth factor β (TGF-β) signaling-related gene polymorphisms with the susceptibility of Stanford type B aortic dissection (AD) and its clinical prognostic outcomes.

Methods

Five single-nucleotide polymorphism (SNPs) (FBN1rs 145233125, rs201170905, rs11070646, TGFB1rs1800469, and TGFB2rs900) were analyzed in patients with Stanford type B AD (164) and healthy controls (317). Gene–gene and gene–environment interactions were assessed by generalized multifactor dimensionality reduction. A 4-year follow-up was performed for all AD patients.

Results

G carriers of FBN1 rs201170905 and TGFB1 rs1800469 have an increased risk of Stanford type B AD. The interaction of FBN1, TGFB1, TGFB2 and environmental promoted to the increased risk of type B AD (cross-validation consistency = 10/10, P = 0.001). Dominant models of FBN1rs145233125 TC + CC genotype (P = 0.028), FBN1 rs201170905 AG + GG (P = 0.047) and TGFB1 rs1800469 AG + GG (P = 0.052) were associated with an increased risk of death of Stanford type B AD. The recessive model of FBN1 rs145233125 CC genotype (P < 0.001), FBN1rs201170905 GG (P < 0.001), TGFB1 rs1800469 AG + GG genotype (P = 0.011) was associated with an increased risk of recurrence of chest pain in Stanford type B AD.

Conclusions

The interactions of gene–gene and gene–environment are related with the risk of Stanford type B AD. C carriers of rs145233125, G carriers of rs201170905 and G carriers of rs1800469 may be the poor clinical outcome indicators of mortality and recurrent chest pain in Stanford type B AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01213-z.

Levels of angiogenesis markers in patients with different heart failure phenotypes

Aim. To assess the relationship between the levels of angiogenesis markers and various heart failure (HF) phenotypes in patients with class II-IV HF of ischemic origin.

Material and methods. This cross-sectional cohort study was based on the clinical departments of the National Medical Research Center for Therapy and Preventive Medicine. The study involved 180 patients aged 30-85 years with class II-IV HF of ischemic origin as follows with (n=90) and without (n=90) metabolic syndrome (MS). All patients included in the study signed an informed consent to personal data processing, participation in a clinical trial and consent to blood biobanking. All patients were divided into three groups: HF with reduced ejection fraction (HFrEF)  — left ventricular (LV) EF <40%, HF with mildly reduced EF (HFmrEF) — LVEF from 40 to 49%, HF with preserved EF (HFpEF)  — LVEF >49%. In addition to the standard paraclinical investigations, angiogenesis markers were analyzed with the determination of transforming growth factor β (TGF-β), vascular endothelial growth factor A (VEGF-A), pentraxin-3 (PTX-3). Statistical analysis was performed using Microsoft Office Excel, STATISTICA 10.0 software packages (Statsoft, USA).

Results. Transthoracic echocardiography determined that 74 (41,1%) patients had LVEF <50%, while 71 (39,4%)  — <40%. For the group of patients with HFpEF, there was an association with an increase in TGF-β ≥7,2 ng/ml (p=0,011). The threshold level of PTX-3 ≥55 ng/ml is associated with the development of HFpEF (p=0,001). For the HFmrEF phenotype, the threshold values of VEGF-A, TGF-β and PTX-3 were determined, which did not reach the significance level. However, an upward trend in VEGF-A >200 ng/ml was noted (p=0,052). In HFrEF patients, a threshold value of VEGF-A >195 ng/ml (p=0,001) associated with reduced LVEF was determined.

Conclusion. Thus, the present work showed the relevance of using PTX-3, VEGF-A and TGF-β as additional markers for assessing the HF course. So, patients with HFpEF had increased levels of PTX-3 and TGF-β, while patients with HFmrEF and HFrEF  — increased VEGF-A values. Determination of the level of these angiogenesis markers should be used to improve the efficiency of diagnosis and treatment of patients with various class II-IV HF phenotypes.

LRG1: an emerging player in disease pathogenesis

The secreted glycoprotein leucine-rich α-2 glycoprotein 1 (LRG1) was first described as a key player in pathogenic ocular neovascularization almost a decade ago. Since then, an increasing number of publications have reported the involvement of LRG1 in multiple human conditions including cancer, diabetes, cardiovascular disease, neurological disease, and inflammatory disorders. The purpose of this review is to provide, for the first time, a comprehensive overview of the LRG1 literature considering its role in health and disease. Although LRG1 is constitutively expressed by hepatocytes and neutrophils, Lrg1-/- mice show no overt phenotypic abnormality suggesting that LRG1 is essentially redundant in development and homeostasis. However, emerging data are challenging this view by suggesting a novel role for LRG1 in innate immunity and preservation of tissue integrity. While our understanding of beneficial LRG1 functions in physiology remains limited, a consistent body of evidence shows that, in response to various inflammatory stimuli, LRG1 expression is induced and directly contributes to disease pathogenesis. Its potential role as a biomarker for the diagnosis, prognosis and monitoring of multiple conditions is widely discussed while dissecting the mechanisms underlying LRG1 pathogenic functions. Emphasis is given to the role that LRG1 plays as a vasculopathic factor where it disrupts the cellular interactions normally required for the formation and maintenance of mature vessels, thereby indirectly contributing to the establishment of a highly hypoxic and immunosuppressive microenvironment. In addition, LRG1 has also been reported to affect other cell types (including epithelial, immune, mesenchymal and cancer cells) mostly by modulating the TGFβ signalling pathway in a context-dependent manner. Crucially, animal studies have shown that LRG1 inhibition, through gene deletion or a function-blocking antibody, is sufficient to attenuate disease progression. In view of this, and taking into consideration its role as an upstream modifier of TGFβ signalling, LRG1 is suggested as a potentially important therapeutic target. While further investigations are needed to fill gaps in our current understanding of LRG1 function, the studies reviewed here confirm LRG1 as a pleiotropic and pathogenic signalling molecule providing a strong rationale for its use in the clinic as a biomarker and therapeutic target.

Proteomic analysis of serum proteins in children with brain death

BACKGROUND

Brain death (BD) is a catastrophic physiological outcome that can occur in individuals with terminal illness and can adversely affect the graft quality after donation of their organs. As BD has no specific symptoms, it can be difficult to diagnose in a timely manner. The present study was designed to investigate the serum protein expression profiles of children affected by BD in an effort to define diagnostic biomarkers for this condition.

METHODS

Blood samples were collected from 8 patients with BD and 8 healthy controls during the same time period. Tandem mass tags and mass spectrometry were used to conduct a proteomic analysis of serum extracted from the samples. The potential regulatory roles of the top 5 upregulated and downregulated proteins identified through the analysis were then explored using bioinformatics analyses and a review of the related literature.

RESULTS

The top 5 upregulated proteins in the serum samples from patients with BD were lipopolysaccharide-binding protein (LBP), α1-acid glycoprotein (α1-AGP), α1-antichymotrypsin (α1-ACT), leucine-rich α1-glycoprotein (LRG1), and lactate dehydrogenase B heavy chain (LDHB), and the 5 most downregulated proteins in these samples were actin-binding protein 2 (transgelin-2), platelet basic protein (PBP), tropomyosin α4 chain (TPM4), tropomyosin α3 chain (TPM3), and peptidase inhibitor 16 (PI16). Literature searches indicated that several of the identified proteins influence the pathogeneses of various diseases, with LBP, α1-AGP, α1-ACT, LRG1, transgelin-2, and PBP all being related to inflammatory activity.

CONCLUSIONS

Through a proteomics-based analysis, several differentially expressed proteins were identified in patients with BD relative to healthy controls. Most of these proteins are associated with inflammatory responses that have the potential to persist after the occurrence of BD. Further clinical work is needed to clarify the functional roles of the identified proteins.

Plasma-derived extracellular vesicles from myocardial infarction patients inhibits tumor necrosis factor-alpha induced cardiac cell death

RATIONALE

Extracellular vesicles (EVs) derived exogenously from pluripotent stem cells or endogenously from healthy human serum exert cardioprotective effects after injury. However role of endogenous EVs from myocardial infarction (MI) patients not well understood in this settings.

METHODS AND RESULTS

The EVs from plasma of MI patients with preserved or reduced left ventricular ejection fraction (LVEF) and healthy controls (HC) were purified and characterized by flow cytometry, mass spectrometry (MS) and transmission electron microscopy (TEM). HCM and human cardiac microvascular endothelial cells (hCMVECs), under individual culture or co-culture, were used to study functional effects of EVs upon TNFα stimulation. These effects of EVs on HCM and hCMVECs were observed using cell death assays, western blots and confocal microscopy. Higher concentrations of platelet-, leukocyte-, endothelial- and erythrocyte-derived EVs were found in MI patients, both with preserved and reduced LVEF, compared to HC, and MS data on MI EVs proteome displayed alteration in several proteins. MI EVs protected HCM and hCMVECs against staurosporine-induced apoptosis. Furthermore, MI EVs were observed to abrogate TNFα-triggered HCM and hCMVECs death under both individually cultured and co-cultured conditions. MI EVs failed to inhibit TNFα induced hCMVECs and HCM activation when cultured individually, however co-cultured hCMVECs with HCM supported MI EVs capacity to attenuate TNFα induced cells activation. MI CD41+ EVs but not HC EVs were found to be internalized by HCM directly or migrated through hCMVECs to HCM. MI EVs indirectly restores TNFα mediated drop in mitochondrial membrane potential.

CONCLUSIONS

Endogenous EVs from MI patients, regardless of severity of the MI exert cardioprotective potential upon TNFα-induced cell death. Patient-derived EVs needs to be further explored to elucidate their potential cardioprotective role during MI.

LRG1 is an adipokine that mediates obesity-induced hepatosteatosis and insulin resistance

Dysregulation in adipokine biosynthesis and function contributes to obesity-induced metabolic diseases. However, the identities and functions of many of the obesity-induced secretory molecules remain unknown. Here, we report the identification of leucine-rich alpha-2-glycoprotein 1 (LRG1) as an obesity-associated adipokine that exacerbates high fat diet-induced hepatosteatosis and insulin resistance. Serum levels of LRG1 were markedly elevated in obese humans and mice compared to their respective controls. LRG1 deficiency in mice greatly alleviated diet-induced hepatosteatosis, obesity, and insulin resistance. Mechanistically, LRG1 bound with high selectivity to the liver and promoted hepatosteatosis by increasing de novo lipogenesis and suppressing fatty acid β-oxidation. LRG1 also inhibited hepatic insulin signaling by down-regulating insulin receptor substrates 1 and 2. Our study identified LRG1 as a key molecule that mediates the crosstalk between adipocytes and hepatocytes in diet-induced hepatosteatosis and insulin resistance. Suppressing LRG1 expression and function may be a promising strategy for the treatment of obesity-related metabolic diseases.

Mechanism of miR-30b-5p-Loaded PEG-PLGA Nanoparticles for Targeted Treatment of Heart Failure

Objective: Exploring the effectiveness of miR-30b-5p-loaded PEG-PLGA nanoparticles (NPs) for the treatment of heart failure and the underlying mechanism.

Methods: PEG-PLGA characteristics with different loading amounts were first examined to determine the loading, encapsulation, and release of miR-30b-5p from NPs. The effects of miR-30b-5p NPs on cardiac function and structure were assessed by immunofluorescence, echocardiography, HE/Masson staining, and TUNEL staining. The effects of NPs on the expression of factors related to cardiac hypertrophy and inflammation were examined by RT-PCR and western blotting, and the mechanism of miR-30b-5p treatment on heart failure was explored by dual luciferase reporter assay and RT-PCR.

Results: The size of PEG-PLGA NPs with different loading amounts ranged from 200 to 300 nm, and the zeta potential of PEG-PLGA NPs was negative. The mean entrapment efficiency of the NPs for miR-30b-5p was high (81.8 ± 2.1%), and the release rate reached 5 days with more than 90% release. Distribution experiments showed that NPs were mainly distributed in the heart and had a protective effect on myocardial injury and cardiac function. Compared with a rat model of cardiac failure and miR-30b-5p-non-loaede NP groups, the expression of cardiac hypertrophy markers (ANP, BNPβ-MHC) and inflammatory factors (IL-1β, IL-6) were significantly decreased. Dual luciferase reporter assay assays indicated that miR-30b-5p exerted its effects mainly by targeting TGFBR2.

Conclusion: PEG-PLGA NPs loaded with miR-30b-5p improved cardiac function, attenuated myocardial injury, and regulated the expression of factors associated with cardiac hypertrophy and inflammation by targeting TGFBR2.

Serum LRG1 as a novel biomarker for cardioembolic stroke

BACKGROUND

In recent years, LRG1 was found to be closely related to atrial fibrillation, heart failure, and myocardial remodeling after myocardial infarction. While its role in cerebral infarction was still controversial. We aimed to explore the value of LRG1 to identify the cardioembolic stroke.

METHODS

283 acute ischemic stroke(AIS) patients and 169 controls were enrolled. The AIS patients were divided into a CE(cardiogenic embolism) group and a non-CE group. Serum LRG1 levels were quantified by ELISA.

RESULTS

The serum LRG1 levels were decreased in the AIS patients. CE group had higher serum LRG1 levels than the non-CE group. LRG1 was an independent risk factor for cardioembolic stroke. The area under the curve (AUC) was 0.768 with a sensitivity of 72.5% and specificity of 69.5%, which was not second to BNP and LAD. The combined predictive model we designed, including LRG1, BNP, and LAD, greatly improved the prediction effect. A positive correlation was shown between LRG1 and stroke severity in the CE group. Those who experienced poor outcomes had higher serum LRG1 levels compared with good ones.

CONCLUSION

Serum LRG1 was a promising indicator to predict cardioembolic stroke, as well as stroke severity and the 3-month prognosis of it.

LRG1 promotes epithelial-mesenchymal transition of retinal pigment epithelium cells by activating NOX4

AIM

To investigate the effect of leucine-rich-alpha-2-glycoprotein 1 (LRG1) on epithelial-mesenchymal transition (EMT) in retinal pigment epithelium (RPE) cells, and to explore the role of NADPH oxidase 4 (NOX4).

METHODS

RPE cells (ARPE-19 cell line) were treated with transforming growth factor-β1 (TGF-β1) to induce EMT. Changes of the mRNA and protein expression levels of LRG1 were tested in the TGF-β1 treated cells. The recombinant human LRG1 protein (rLRG1) and siRNA of LRG1 were used to establish accumulation of exogenous LRG1 model and the down-regulation of LRG1 model in ARPE-19 cells respectively, and to detect EMT-related markers including fibronectin, α-smooth muscle actin (α-SMA) and zonula occludens-1 (ZO-1). The mRNA and protein expression level of NOX4 were measured according to the above treatments. VAS2870 was used as a NOX4 inhibitor in rLRG1-treated cells. EMT-related markers were detected to verify the effect of NOX4 in the process of EMT.

RESULTS

TGF-β1 promoted the expression of LRG1 at both the mRNA and protein levels during the process of EMT which showed the up-regulation of fibronectin and α-SMA, as well as the down-regulation of ZO-1. Furthermore, the rLRG1 promoted EMT of ARPE-19 cells, which manifested high levels of fibronectin and α-SMA and low level of ZO-1, whereas knockdown of LRG1 prevented EMT by decreasing the expressions of fibronectin and α-SMA and increasing the expression of ZO-1 in ARPE-19 cells. Besides, the rLRG1 activated and LRG1 siRNA suppressed NOX4 expression. EMT was inhibited when VAS2870 was used in the rLRG1-treated cells.

CONCLUSION

These results for the first time demonstrate that LRG1 promotes EMT of RPE cells by activating NOX4, which may provide a novel direction to explore the mechanisms of subretinal fibrosis.

Identification and Validation of Leucine-rich α-2-glycoprotein 1 as a Noninvasive Biomarker for Improved Precision in Prostate Cancer Risk Stratification

Background

More accurate risk assessments are needed to improve prostate cancer management.

Objective

To identify blood-based protein biomarkers that provided prognostic information for risk stratification.

Design, setting, and participants

Mass spectrometry was used to identify biomarker candidates from blood, and validation studies were performed in four independent cohorts retrospectively collected between 1988 and 2015.

Outcome measurements and statistical analysis

The primary outcome objectives were progression-free survival, prostate cancer–specific survival (PCSS), and overall survival. Statistical analyses to assess survival and model performance were performed.

Results and limitation

Serum leucine-rich α-2-glycoprotein 1 (LRG1) was found to be elevated in fatal prostate cancer. LRG1 provided prognostic information independent of metastasis and increased the accuracy in predicting PCSS, particularly in the first 3 yr. A high LRG1 level is associated with an average of two-fold higher risk of disease-progression and mortality in both high-risk and metastatic patients. However, our study design, with a retrospective analysis of samples spanning several decades back, limits the assessment of the clinical utility of LRG1 in today’s clinical practice. Thus, independent prospective studies are needed to establish LRG1 as a clinically useful biomarker for patient management.

Conclusions

High blood levels of LRG1 are unfavourable in newly diagnosed high-risk and metastatic prostate cancer, and LRG1 increased the accuracy of risk stratification of prostate cancer patients.

Patient summary

High blood levels of leucine-rich α-2-glycoprotein 1 are unfavourable in newly diagnosed high-risk and metastatic prostate cancer.

MicroRNA-497 elevation or LRG1 knockdown promotes osteoblast proliferation and collagen synthesis in osteoporosis via TGF-β1/Smads signalling pathway

MicroRNAs (miRNAs) have been corroborated to engage in the process of cellular activities in osteoporosis. However, few researches have been conducted to expose the integrated role of miR‐497, leucine‐rich alpha‐2‐glycoprotein‐1 (LRG1) and transforming growth factor beta 1 (TGF‐β1)/Smads signalling pathway in osteoporosis. Thereafter, the study is set out to delve into miR‐497/LRG1/TGF‐β1/Smads signalling pathway axis in osteoporosis. Osteoporosis bone tissues and normal bone tissues were collected. Rat osteoporosis models were constructed via ovariectomy. Model rats were injected with restored miR‐497 or depleted LRG1 to explore their roles in osteoporosis. Rat osteoblasts were extracted from osteoporosis rats and transfected with restored miR‐497 or depleted LRG1 for further verification. MiR‐497 and LRG1 expression in femoral head tissues and osteoblasts of osteoporosis rats were detected. TGF‐β1/Smads signalling pathway‐related factors were detected. MiR‐497 was poorly expressed while LRG1 was highly expressed and TGF‐β1/Smads signalling pathway activation was inhibited in osteoporosis. MiR‐497 up‐regulation or LRG1 down‐regulation activated TGF‐β1/Smads signalling pathway, promoted collagen type 1 synthesis and suppressed oxidative stress in femoral head tissues in osteoporosis. MiR‐497 restoration or LRG1 knockdown activated TGF‐β1/Smads signalling pathway, promoted viability and suppressed apoptosis of osteoblasts in osteoporosis. Our study suggests that miR‐497 up‐regulation or LRG1 down‐regulation promotes osteoblast viability and collagen synthesis via activating TGF‐β1/Smads signalling pathway, which may provide a novel reference for osteoporosis treatment.

The Clinical Prognostic Value of LRG1 in Esophageal Squamous Cell Carcinoma

BACKGROUND

Leucine-rich-alpha-2-glycoprotein1 (LRG1) is a new oncogene-related gene, which has been proven important for the development and poor prognosis of human cancers. However, whether it participates in esophageal squamous cell carcinoma (ESCC) progression remains unclear.

OBJECTIVE

To investigate the expression level and functional influence of LRG1 in ESCC.

METHODS

The expression of LRG1 was evaluated on the mRNA and protein level in ESCC patients. Then, correlation of LRG1 expression with clinicpathological variables was analyzed in ESCC. Besides, to clarify the biological function of LRG1, Eca109 and KYSE150 cells were transfected with LRG1 shRNA, the cell viability, clonal efficiency, apoptosis and invasion assays in vitro were performed.

RESULTS

LRG1 was significantly over-expressed in ESCC and related to deeper invasion depth (T stage) and distal metastasis (M stage). Kaplan-Meier analysis indicated that LRG1 up-regulation in ESCC was closely correlated to worse clinical survival (overall survival and progression-free survival), all P<0.001. LRG1 was confirmed to be an independent poor premonitory indicator for clinical outcomes in ESCC through the univariate and multivariate analyses. Down-regulation of LRG1 in ESCC cells markedly suppressed cell proliferation and invasion, stimulated apoptosis (all p <0.01).

CONCLUSION

LRG1 might play a significant role in the progression of ESCC, and could be served as a promising prognostic prediction for ESCC patients.

Role of VEGF-A and LRG1 in Abnormal Angiogenesis Associated With Diabetic Nephropathy

Diabetic nephropathy (DN) is an important public health concern of increasing proportions and the leading cause of end-stage renal disease (ESRD) in diabetic patients. It is one of the most common long-term microvascular complications of diabetes mellitus that is characterized by proteinuria and glomerular structural changes. Angiogenesis has long been considered to contribute to the pathogenesis of DN, whereas the molecular mechanisms of which are barely known. Angiogenic factors associated with angiogenesis are the major candidates to explain the microvascular and pathologic finds of DN. Vascular endothelial growth factor A (VEGF-A), leucine-rich α-2-glycoprotein 1, angiopoietins and vasohibin family signal between the podocytes, endothelium, and mesangium have important roles in the maintenance of renal functions. An appropriate amount of VEGF-A is beneficial to maintaining glomerular structure, while excessive VEGF-A can lead to abnormal angiogenesis. LRG1 is a novel pro-angiogenic factors involved in the abnormal angiogenesis and renal fibrosis in DN. The imbalance of Ang1/Ang2 ratio has a role in leading to glomerular disease. Vasohibin-2 is recently shown to be in diabetes-induced glomerular alterations. This review will focus on current understanding of these angiogenic factors in angiogenesis and pathogenesis associated with the development of DN, with the aim of evaluating the potential of anti-angiogenesis therapy in patients with DN.

Angiogenesis in Patients with Chronic Heart Failure: Focus on Endothelial Vascular Growth Factor, Pentraxin-3 and Transforming Growth Factor Beta

Chronic heart failure (CHF) is considered the leading cause of death in patients with established cardiovascular (CVD) and metabolic diseases. Although the current treatment strategy has improved survival and clinical outcomes, the prevalence of CHF shows an increase. Current clinical guidelines for the treatment and prevention of CVD note the role of biological markers as a fairly simple and powerful tool for diagnosing, stratifying risk and predicting CHF. However, it is unclear whether all of these biological markers are equally capable of predicting cardiovascular mortality and heart failure related outcomes in patients with acute and chronic heart failure, as well as in different phenotypes of heart failure. However, the results of numerous studies demonstrate scientific interest in the processes of angiogenesis among patients with CHF. There is an impressive body of evidence linking CHF to the level of markers such as vascular endothelial growth factor, pentraxin-3, and transforming growth factor beta. The review presents the data of domestic and foreign clinical studies devoted to the study of the level of angiogenesis markers among patients with CHF.

Clinical Proteomics Profiling for Biomarker Identification Among Patients Suffering With Indian Post Kala Azar Dermal Leishmaniasis

Background: Post Kala Azar Dermal Leishmaniasis (PKDL) is a non-fatal dermal sequel of Visceral Leishmaniasis (VL), affecting individuals worldwide. Available diagnostic tools lack sensitivity and specificity toward identifying macular (MAC) PKDL patients, due to low parasite load in patients' sample. Confirmatory test like punch biopsy are invasive and painful. Considering the rural nature of this disease and the prevailing situation of diagnostic scenario, PKDL patients mostly remains unattended from receiving proper medical care. They in turn act as “mobile parasite reservoir,” responsible for VL transmission among healthy individuals (HI). This study aims to identify PKDL disease specific glycated protein biomarkers, utilizing the powerful LC-MS/MS technology, which is the tool of choice to efficiently identify and quantify disease specific protein biomarkers. These identified PKDL disease specific novel glycoproteins could be developed in future as immunochromatographic based assay for efficient case detection.

Methodology: Previously our lab had identified importance of glycated (Circulating Immune Complexes) CICs, among PKDL patients. This study aims to further characterize disease specific glycated protein biomarkers, among MAC PKDL patients for both diagnostic and prognostic evaluation of the disease. LC-MS/MS based comparative spectral count analysis of MAC PKDL to polymorphic (POLY) PKDL, HI, and Cured (CR) individuals were performed. Proteins level alterations among all study groups were confirmed by Western blot and enzyme-linked immunosorbant Assay (ELISA).

Results: Among MAC PKDL patients 43, 60, 90 proteins were altered compared to POLY PKDL, HI, and CR groups, respectively. Filtering for the most significant proteins, Plasminogen (PLG) and Vitronectin (VTN) were identified which promisingly identified MAC PKDL cases. Active surveillance results from endemic districts of West Bengal revealed drastic rise of MAC PKDL cases, alarming the urgency for field adaptive efficient biomarker.

Conclusion: This current study aims to establish PLG and VTN as novel diagnostic and prognostic protein biomarker for MAC and POLY PKDL cases management.

Cardiovascular-renal axis disorder and acute-phase proteins in cats with congestive heart failure caused by primary cardiomyopathy

BACKGROUND

Currently, the pathogenesis of congestive heart failure (CHF) in cats is not fully understood.

OBJECTIVE

To identify novel biomarkers for CHF in cats caused by primary cardiomyopathy, particularly related to cardiovascular-renal axis disorder and systemic inflammatory response.

ANIMALS

Twenty-five cats in CHF caused by primary cardiomyopathy, 12 cats with preclinical cardiomyopathy, and 20 healthy controls.

METHODS

Case control and observational case series. The following serum biomarkers were compared among the 3 cat groups: a cardiorenal profile that included N-terminal pro-brain natriuretic peptide (NT-proBNP), symmetric dimethylarginine (SDMA), and creatinine and an inflammatory profile that included 7 acute-phase proteins (APPs). Survival analyses and longitudinal studies were performed in CHF cats.

RESULTS

All cardiorenal biomarkers were positively correlated and higher in CHF cats, and high NT-proBNP and SDMA were associated with poor clinical outcome. Cats with CHF had significantly higher leucine-rich alpha-2-glycoprotein 1, serum amyloid A, and ceruloplasmin, and these APPs were positively correlated with NT-proBNP and left atrial size. In a multivariable survival analysis, alpha-1-acid glycoprotein concentration (P = .01), body weight (P = .02) and left atrial-to-aortic root ratio (P = .01) were independent prognostic factors for CHF in these cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

In cats, CHF is an inflammatory disorder and outcome in CHF may be determined by the extent of inflammation and possibly the amount of residual renal function. These novel biomarkers have potential use for the clinical management, prognosis, and future research into CHF and cardiomyopathy in cats.

Identification of the initial molecular changes in response to circulating angiogenic cells-mediated therapy in critical limb ischemia

Background

Critical limb ischemia (CLI) constitutes the most aggressive form of peripheral arterial occlusive disease, characterized by the blockade of arteries supplying blood to the lower extremities, significantly diminishing oxygen and nutrient supply. CLI patients usually undergo amputation of fingers, feet, or extremities, with a high risk of mortality due to associated comorbidities.

Circulating angiogenic cells (CACs), also known as early endothelial progenitor cells, constitute promising candidates for cell therapy in CLI due to their assigned vascular regenerative properties. Preclinical and clinical assays with CACs have shown promising results. A better understanding of how these cells participate in vascular regeneration would significantly help to potentiate their role in revascularization.

Herein, we analyzed the initial molecular mechanisms triggered by human CACs after being administered to a murine model of CLI, in order to understand how these cells promote angiogenesis within the ischemic tissues.

Methods

Balb-c nude mice (n:24) were distributed in four different groups: healthy controls (C, n:4), shams (SH, n:4), and ischemic mice (after femoral ligation) that received either 50 μl physiological serum (SC, n:8) or 5 × 10⁵ human CACs (SE, n:8). Ischemic mice were sacrificed on days 2 and 4 (n:4/group/day), and immunohistochemistry assays and qPCR amplification of Alu-human-specific sequences were carried out for cell detection and vascular density measurements. Additionally, a label-free MS-based quantitative approach was performed to identify protein changes related.

Results

Administration of CACs induced in the ischemic tissues an increase in the number of blood vessels as well as the diameter size compared to ischemic, non-treated mice, although the number of CACs decreased within time. The initial protein changes taking place in response to ischemia and more importantly, right after administration of CACs to CLI mice, are shown.

Conclusions

Our results indicate that CACs migrate to the injured area; moreover, they trigger protein changes correlated with cell migration, cell death, angiogenesis, and arteriogenesis in the host. These changes indicate that CACs promote from the beginning an increase in the number of vessels as well as the development of an appropriate vascular network.

Graphical abstract

Expression Profile Analysis of Selenium-Related Genes in Peripheral Blood Mononuclear Cells of Patients with Keshan Disease

Keshan disease (KD) is an endemic cardiomyopathy, which mainly occurs in China. Selenium deficiency is believed to play an important role in the pathogenesis of KD, but the molecular mechanism of selenium-induced damage remains unclear. To identify the key genes involved in selenium-induced damage, we compared the expression profiles of selenium-related genes between patients with KD and normal controls. Total RNA was isolated, amplified, labeled, and hybridized to Agilent human 4 × 44 K whole genome microarrays. Selenium-related genes were screened using the Comparative Toxicogenomics Database. The microarray data were subjected to single-gene and gene ontology (GO) expression analysis using R Studio and Gene Set Enrichment Analysis (GSEA) software. Quantitative real-time PCR was conducted to validate the microarray results. We identified 16 upregulated and 11 downregulated selenium-related genes in patients. These genes are involved in apoptosis, metabolism, transcription regulation, ion transport, and growth and development. Of the significantly enriched GO categories in KD patients, we identified four apoptosis-related, two metabolism-related, four growth and development-related, and four ion transport-related GOs. Based on our results, we suggest that selenium might contribute to the development of KD through dysfunction of selenium-related genes involved in apoptosis, metabolism, ion transport, and growth and development in the myocardium.

Proteomic Identification of Biomarkers Associated with Eating Control and Bariatric Surgery Outcomes in Patients with Morbid Obesity

BACKGROUND

The current therapeutics of morbid obesity could be significantly improved after the identification of novel biomarkers associated with the food addiction endophenotype of obesity and with bariatric surgery outcomes.

METHODS

We applied differential expression proteomics and enzyme-linked immunosorbent confirmatory assays to identify (a) proteins that varied according to loss of control over eating in morbidly obese patients and (b) proteins that varied between normoweight controls and patients before and 1 year after bariatric surgery.

RESULTS

Clusterin was the only protein that consistently varied according to eating control in patients. Patients showed increased levels of serum amyloid P protein, apolipoprotein A4, serotransferrin, complement factors B and C3 and haptoglobin with respect to controls; the levels of all these proteins tended to return to control values 1 year after surgery. In contrast, apolipoprotein A1 and transthyretin were initially downregulated in patients and were scarcely changed by surgery. Leucine-rich alpha-2-glycoprotein was markedly increased in patients only after surgery.

CONCLUSIONS

Clusterin could be of interest as a putative biomarker for food addiction diagnosis in people with morbid obesity. In addition, postsurgical normalization of the proteins initially dysregulated in obese subjects might help monitor clinical improvements after surgery, while lasting or newly detected alterations (i.e., those affecting transthyretin and leucine-rich alpha-2-glycoprotein) could reflect partial refractoriness and/or contribute to the early prediction of clinical problems.

Oxymatrine Inhibits Transforming Growth Factor β1 (TGF-β1)-Induced Cardiac Fibroblast-to-Myofibroblast Transformation (FMT) by Mediating the Notch Signaling Pathway In Vitro

Background

Oxymatrine, a component extracted from the traditional Chinese herb Sophora japonica (Sophora flavescens Ait.), has various pharmacological effects, especially on the cardiovascular system. However, its cardiac protection effects and the underlying mechanism are still poorly understood. In the present study, we investigated the inhibitory effect and mechanism of oxymatrine on cardiac fibrosis induced by TGF-β1.

Material/Methods

Cardiac fibroblasts were isolated and purified from neonatal rats. Immunocytochemical staining was used to identify the cells. MTT assay and immunofluorescence staining were used to assess cardiac fibroblasts proliferation and myofibroblasts transformation. Hematoxylin-eosin staining was performed to evaluate morphological changes of cardiac fibroblasts. The secretion of type I and III collagen was assessed by staining with picrosirius red and the hydroxyproline content was determined by colorimetric assay. Cardiac fibroblast migration was examined by scratch assay and DNA content was detected to analyze cell cycle distribution using flow cytometry. Western blot analysis was used to detect the protein expressions of Notch pathway-associated protein in cardiac fibroblasts.

Results

Oxymatrine and Notch signaling pathway inhibitor DAPT could attenuated TGF-β1 induced the capacity of proliferation and migration increased in cardiac fibroblasts, as well as the secretion of collagen and hydroxyproline colorimetric content in medium. TGF-β1 induced the biomarker α-SMA of fibroblast-to-myofibroblast transformation (FMT), which was inhibited by oxymatrine and DAPT. Western blotting confirmed that oxymatrine blocked the activation of Notch induced by TGF-β1.

Conclusions

Oxymatrine is a potential inhibitor FMT induced by TGF-β1, which is at least in part mediated via inhibition of Notch signaling.

High-throughput serum proteomics for the identification of protein biomarkers of mortality in older men

The biological perturbations associated with incident mortality are not well elucidated, and there are limited biomarkers for the prediction of mortality. We used a novel high‐throughput proteomics approach to identify serum peptides and proteins associated with 5‐year mortality in community‐dwelling men age ≥65 years who participated in a longitudinal observational study of musculoskeletal aging (Osteoporotic Fractures in Men: MrOS). In a discovery phase, serum specimens collected at baseline in 2473 men were analyzed using liquid chromatography–ion mobility–mass spectrometry, and incident mortality in the subsequent 5 years was ascertained by tri‐annual questionnaire. Rigorous statistical methods were utilized to identify 56 peptides (31 proteins) that were associated with 5‐year mortality. In an independent replication phase, selected reaction monitoring was used to examine 21 of those peptides in baseline serum from 750 additional men; 81% of those peptides remained significantly associated with mortality. Mortality‐associated proteins included a variety involved in inflammation or complement activation; several have been previously linked to mortality (e.g., C‐reactive protein, alpha 1‐antichymotrypsin) and others are not previously known to be associated with mortality. Other novel proteins of interest included pregnancy‐associated plasma protein, VE‐cadherin, leucine‐rich α‐2 glycoprotein 1, vinculin, vitronectin, mast/stem cell growth factor receptor, and Saa4. A panel of peptides improved the predictive value of a commonly used clinical predictor of mortality. Overall, these results suggest that complex inflammatory pathways, and proteins in other pathways, are linked to 5‐year mortality risk. This work may serve to identify novel biomarkers for near‐term mortality.

Effect of Riociguat and Sildenafil on Right Heart Remodeling and Function in Pressure Overload Induced Model of Pulmonary Arterial Banding

Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by remodeling of the pulmonary vasculature and a rise in right ventricular (RV) afterload. The increased RV afterload leads to right ventricular failure (RVF) which is the reason for the high morbidity and mortality in PAH patients. The objective was to evaluate the therapeutic efficacy and antiremodeling potential of the phosphodiesterase type 5 (PDE5) inhibitor sildenafil and the soluble guanylate cyclase stimulator riociguat in a model of pressure overload RV hypertrophy induced by pulmonary artery banding (PAB). Mice subjected to PAB, one week after surgery, were treated with either sildenafil (100 mg/kg/d, n = 5), riociguat (30 mg/kg/d, n = 5), or vehicle (n = 5) for 14 days. RV function and remodeling were assessed by right heart catheterization, magnetic resonance imaging (MRI), and histomorphometry. Both sildenafil and riociguat prevented the deterioration of RV function, as determined by a decrease in RV dilation and restoration of the RV ejection fraction (EF). Although both compounds did not decrease right heart mass and cellular hypertrophy, riociguat prevented RV fibrosis induced by PAB. Both compounds diminished TGF-beta1 induced collagen synthesis of RV cardiac fibroblasts in vitro. Treatment with either riociguat or sildenafil prevented the progression of pressure overload-induced RVF, representing a novel therapeutic approach.

Leucine-rich α2-glycoprotein overexpression in the brain contributes to memory impairment

We previously reported increase in leucine-rich α2-glycoprotein (LRG) concentration in cerebrospinal fluid is associated with cognitive decline in humans. To investigate relationship between LRG expression in the brain and memory impairment, we analyzed transgenic mice overexpressing LRG in the brain (LRG-Tg) focusing on hippocampus. Immunostaining and Western blotting revealed age-related increase in LRG expression in hippocampal neurons in 8-, 24-, and 48-week-old controls and LRG-Tg. Y-maze and Morris water maze tests indicated retained spatial memory in 8- and 24-week-old LRG-Tg, while deteriorated in 48-week-old LRG-Tg compared with age-matched controls. Field excitatory postsynaptic potentials declined with age in LRG-Tg compared with controls at 8, 24, and 48 weeks. Paired-pulse ratio decreased with age in LRG-Tg, while increased in controls. As a result, long-term potentiation was retained in 8- and 24-week-old LRG-Tg, whereas diminished in 48-week-old LRG-Tg compared with age-matched controls. Electron microscopy observations revealed fewer synaptic vesicles and junctions in LRG-Tg compared with age-matched controls, which became significant with age. Hippocampal LRG overexpression contributes to synaptic dysfunction, which leads to memory impairment with advance of age.

Delivery of growth factor-based therapeutics in vascular diseases: Challenges and strategies

Either cardiovascular or peripheral vascular diseases have become the major cause of morbidity and mortality worldwide. Recently, growth factors therapeutics, whatever administrated in form of exogenous growth factors or their relevant genes have been discovered to be an effective strategy for the prevention and therapy of vascular diseases, because of their promoting angiogenesis. Besides, as an alternative, stem cell-based therapy has been also developed in view of their paracrine-mediated effect or ability of differentiation toward angiogenesis-related cells under assistance of growth factors. Despite of being specific and potent, no matter growth factors or stem cells-based therapy, their full clinical transformation is limited from bench to bedside. In this review, the potential choices of therapeutic modes based on types of different growth factors or stem cells were firstly summarized for vascular diseases. The confronted various challenges such as lack of non-invasive delivery method, the physiochemical challenge, the short half-life time, and poor cell survival, were carefully analyzed for these therapeutic modes. Various strategies to overcome these limitations are put forward from the perspective of drug delivery. The expertised design of a suitable delivery form will undoubtedly provide valuable insight into their clinical application in the regenerative medicine.

Identification of candidate diagnostic serum biomarkers for Kawasaki disease using proteomic analysis

Kawasaki disease (KD) is a systemic vasculitis and childhood febrile disease that can lead to cardiovascular complications. The diagnosis of KD depends on its clinical features, and thus it is sometimes difficult to make a definitive diagnosis. In order to identify diagnostic serum biomarkers for KD, we explored serum KD-related proteins, which differentially expressed during the acute and recovery phases of two patients by mass spectrometry (MS). We identified a total of 1,879 proteins by MS-based proteomic analysis. The levels of three of these proteins, namely lipopolysaccharide-binding protein (LBP), leucine-rich alpha-2-glycoprotein (LRG1), and angiotensinogen (AGT), were higher in acute phase patients. In contrast, the level of retinol-binding protein 4 (RBP4) was decreased. To confirm the usefulness of these proteins as biomarkers, we analyzed a total of 270 samples, including those collected from 55 patients with acute phase KD, by using western blot analysis and microarray enzyme-linked immunosorbent assays (ELISAs). Over the course of this experiment, we determined that the expression level of these proteins changes specifically in the acute phase of KD, rather than the recovery phase of KD or other febrile illness. Thus, LRG1 could be used as biomarkers to facilitate KD diagnosis based on clinical features.

LRG1 promotes angiogenesis through upregulating the TGF‑β1 pathway in ischemic rat brain

Stroke is a life-threatening disease that results in significant disability in the human population. Despite the advances in current stroke therapies, a host of patients do not benefit from the conventional treatments. Thus, more effective therapies are required. It has been previously reported that leucine-rich-α2-glycoprotein 1 (LRG1) is crucial during the formation of new blood vessels in retinal diseases. However, the function of LRG1 in the brain during the neovessel growth process following ischemic stroke has not been fully elucidated and the mechanism underlying its effect on angiogenesis remains unclear. The purpose of the current study was to demonstrate whether LRG1 may promote angiogenesis through the transforming growth factor (TGF)-β1 signaling pathway in ischemic rat brain following middle cerebral artery occlusion (MCAO). In the present study, the spatial and temporal expression of LRG1, TGF-β1, vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) were detected in ischemic rat brain following MCAO using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and immunohistochemistry. CD34 immunohistochemistry staining was used as an indicator of microvessel density (MVD). The RT-qPCR and western blotting results revealed that the levels of LRG1 and TGF-β1 mRNA and protein expression were significantly increased as early as 6 and 12 h after MCAO (P<0.05), respectively, peaked at 3 days and persisted at significantly higher level until 14 days, in comparison with the control group. Additionally, VEGF and Ang-2 were also increased following MCAO. Furthermore, the immunohistochemistry results suggested that the MVD was increased following MCAO. In addition, the results also revealed that the percentage of LRG1-positive cells was positively correlated with the percentage of TGF-β1-positive cells, and the percentage of LRG1-positive and TGF-β1-positive cells had a positively correlation with the MVD. Taken together, the present study indicated that LRG1 may promote angiogenesis through upregulating the TGF-β1 signaling pathway in ischemic rat brain following MCAO. This may provide a potential therapeutic target for the treatment of ischemic stroke.

LRG1 expression indicates unfavorable clinical outcome in hepatocellular carcinoma

Leucine-rich-alpha-2-glycoprotein1 (LRG1) is a novel oncogene-associated protein which has been clarified vital to the progression of human cancers, but its role in hepatocellular carcinoma (HCC) remains unclear. Here, we showed that the expression of LRG1 was noticeably increased in HCC tissues, compared to the nontumorous tissues. High LRG1 expression was significantly associated with tumor size (P = 0.004), tumor differentiation (P = 0.010), TNM stage (P < 0.001) and vascular invasion (P = 0.019). Kaplan-Meier analysis showed that LRG1 expression was closely correlated to overall survival and disease-free survival in a training cohort of 474 patients with HCC. The correlation was further validated in an independent cohort of 303 HCC patients. The prognostic implication of LRG1 was confirmed by stratified survival analyses. Multivariate Cox regression model indicated LRG1 as an independent poor prognostic indicator for overall survival (Hazard ratio = 1.582, 95% confident interval: 1.345–1.862, P < 0.001) and disease-free survival (Hazard ratio = 1.280, 95% confident interval: 1.037–1.581, P = 0.022) in HCC. In vitro data showed that LRG1 markedly promoted cell migration but has no effect on cell proliferation. Collectively, our data show that LRG1 is markedly up-regulated and serves as an independent factor of poor outcomes in HCC. Our study therefore provides a promising biomarker for prognostic prediction in clinical management of HCC.

Activin A stimulates the proliferation and differentiation of cardiac fibroblasts via the ERK1/2 and p38-MAPK pathways

Activin A is a key regulator of cardiac fibrosis. However, little is known about the mechanisms by which it contributes to cardiac fibrosis. Our study explored the effects of activin A on proliferation and differentiation of adult rat cardiac fibroblasts (CFs) via the activin A receptor, activin receptor-like kinase 4 (ALK4). CF proliferation was measured by CCK8 and EdU assays, while differentiation, fibrosis and signaling were measured by western blot analysis of α-smooth muscle actin, collagen type I, phosphorylated extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (p38-MAPK) expression. Activin A levels were measured by ELISA and western blot analysis. We demonstrated that CFs express activin A and its expression was significantly enhanced by angiotensin II (Ang II), but follistatin (activin A inhibitor) significantly reversed Ang II-induced activin A upregulation, CF proliferation, differentiation, collagen type I expression as well as ERK1/2 and p38-MAPK pathways activation. Conversely, recombinant activin A largely increased these parameters in both the presence and absence of Ang II. Interestingly, p38-MAPK (SB203580) and ALK4 (SB431542) inhibitors significantly reduced all activin A-mediated responses; however, an ERK1/2 inhibitor (PD98059) could only significantly reduce CF proliferation and collagen type I expression but not differentiation. Importantly, the most significant effects were observed in the presence vs. absence of Ang II. Thus, activin A promotes basal and Ang II-induced CF proliferation and differentiation via ALK4, and the effects are partly mediated through the ERK1/2 and p38-MAPK pathways. These data suggest that activin A is a potential therapeutic target for cardiac fibrosis.

Sex differences in porcine left ventricular myocardial remodeling due to right ventricular pacing

Background

Although sex differences in heart failure (HF) prevalence and severity have been recognized, its molecular mechanisms are poorly understood. We used a tachycardia-induced cardiomyopathy model to determine the sex specific remodeling pattern in male and female adult pigs.

Methods

We compared the echocardiographic and molecular measures of myocardial remodeling in 19 male and 12 female pigs with chronic symptomatic systolic HF due to right ventricle (RV) pacing (170 bpm) and 6 male and 5 female sham-operated controls. Males achieved subsequent HF stages earlier than females.

Results

The progression of symptomatic HF was associated with the reduction of the left ventricle (LV) ejection fraction in both sexes (all p < 0.05). A significant LV dilatation occurred only in males (p < 0.001). The HF development was accompanied by an increased pro-hypertrophic factor GATA4 and TGF-β1 messenger RNA (mRNA) expression in the LV only in male pigs (all p < 0.01). The total gelatinolytic activity in LV was higher in males than females (irrespective of HF, p < 0.05), and the HF progression was associated with a reduced total gelatinolytic activity (p < 0.05) in the LV only in males. No differences in LV myocardial collagen content were found between HF groups and sexes. Cardiomyocyte cross-sectional diameter was significantly smaller in male hearts as compared to female (p < 0.05).

Conclusions

Male and female porcine hearts respond differently to RV pacing. Males, most likely due to a higher extracellular matrix turnover, demonstrated a significant LV dilatation, followed by a strong induction of pro-hypertrophic program, and an earlier development of symptomatic HF.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-015-0048-4) contains supplementary material, which is available to authorized users.

Pioglitazone regulates myelin phagocytosis and multiple sclerosis monocytes

OBJECTIVE

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Myeloid phagocytes, including blood monocytes recruited to demyelinating lesions, may play a dual role in MS: on one hand, they might enhance CNS damage after differentiating toward a proinflammatory phenotype; on the other, they promote remyelination and repair through effective phagocytosis of myelin debris. We have previously determined that the retinoid X receptor (RXR) plays an important role in monocyte phagocytosis of myelin. Peroxisome proliferator-activated receptor γ is an RXR binding partner that plays a key role in myeloid cell biology and is targeted by the thiazolidinedione group of antidiabetics such as pioglitazone. Consequently, the purpose of this study was to determine if monocyte functions and differentiation profiles differ in MS patients compared to healthy volunteers (HV) and whether pioglitazone can reverse these differences to promote CNS recovery.

METHODS

Monocytes were isolated from MS patients and HV (n ≥ 36/group), and their ability to phagocytose myelin and modulate inflammation in the presence/absence of 1 μmol/L pioglitazone (the in vivo achievable concentration) was quantified by flow cytometry, transcriptional profiling, and proteomic assays.

RESULTS

MS monocytes display impaired phagocytosis of myelin debris and enhanced proinflammatory differentiation. Pioglitazone treatment causes partial normalization of identified monocyte abnormalities in MS and fully reverses the deficit in myelin phagocytosis.

INTERPRETATION

These findings suggest that by inhibiting proinflammatory differentiation of monocytes and enhancing their phagocytosis of myelin, pioglitazone may be a useful adjunct therapy to immunomodulatory agents that target dysregulated adaptive immunity in MS.