Increased Circulating Angiopoietin-Like Protein 8 Levels Are Associated with Thoracic Aortic Dissection and Higher Inflammatory Conditions

Influence of false lumen status on systemic inflammatory response triggered by acute aortic dissection

We investigated the influence of false lumen (FL) status on the systemic inflammatory response triggered by acute aortic dissection (AAD) using cytokine profiling. The study included 44 patients with AAD. Patients were divided between those with a thrombosed FL (Group T, n = 21) and those with a non-thrombosed FL (Group P, n = 23). On-admission serum concentrations of 29 cytokines were compared between unmatched and propensity-score matched (n = 10 pairs) FL groups and a control group (non-ruptured thoracic aortic aneurysm, Group C, n = 20). Unmatched analysis showed 12 cytokines differed between groups and fell into three categories: Category A (increased expression in both FL groups: IL-6, IL-10, IL-15, G-CSF); Category B (increased expression only in Group P: IL-1Ra, IL-1β, IL-8, IL-12p70, GM-CSF); and Category C (others: IP-10, VEGF-A, eotaxin). The increases in Category A and Category B cytokines in Group T were attenuated, but not significantly, compared to their increases in Group P. Propensity-score matching analysis revealed a similar expression pattern with respect to all four Category A cytokines, four Category B cytokines (IL-1β, IL-1Ra, IL-12p70, and GM-CSF), and two Category C cytokines (IP-10 and VEGF-A). A robust inflammatory response occurs in patients with AAD, but the response is attenuated when the FL is thrombosed.

Adipocyte Angptl8 deletion improves glucose and energy metabolism and obesity associated inflammation in mice

Angiopoietin-like protein 8 (Angptl8), expressed in the liver and adipocytes, forms a complex with Angptl3 or Angptl4, which regulates lipoprotein lipase and triglyceride metabolism. However, the precise functions of adipocyte Angptl8 remain elusive. Here we report that adipocyte-specific inducible Angptl8-knockout (AT-A8-KO) male mice on normal diet showed minor phenotypic changes, but after a high-fat high fructose (HFHF) diet, exhibited decreased body weight gain and glycemia, elevated rectal temperature and early dark phase energy expenditure compared to the Cre controls. AT-A8-KO mice also displayed improved glucose tolerance, a trend for better insulin sensitivity, improved insulin-stimulated glucose uptake in adipose tissues, and reduced visceral adipose tissue crown-like structures, plasma MCP-1 and leptin levels. The results indicate the importance of adipose Angptl8 in the context of nutri-stress and obesity, as its deletion in mice promotes a metabolically healthy obese phenotype by slightly ameliorating obesity, improving glucose and energy homeostasis, and mitigating inflammation.

CircNRIP1 promotes proliferation, migration and phenotypic switch of Ang II-induced HA-VSMCs by increasing CXCL5 mRNA stability via recruiting IGF2BP1

Circular RNA (circRNA) has been found to be differentially expressed and involved in regulating the processes of human diseases, including thoracic aortic dissection (TAD). However, the role and mechanism of circNRIP1 in the TAD process are still unclear. GEO database was used to screen the differentially expressed circRNA and mRNA in type A TAD patients and age-matched normal donors. Angiotensin II (Ang II)-induced human aortic vascular smooth muscle cells (HA-VSMCs) were used to construct TAD cell models. The expression levels of circNRIP1, NRIP1, CXC-motif chemokine 5 (CXCL5) and IGF2BP1 were detected by quantitative real-time PCR. Cell proliferation and migration were determined by EdU assay, transwell assay and wound healing assay. The protein levels of synthetic phenotype markers, contractile phenotype markers, CXCL5 and IGF2BP1 were tested by western blot analysis. The interaction between IGF2BP1 and circNRIP1/CXCL5 was confirmed by RIP assay, and CXCL5 mRNA stability was assessed by actinomycin D assay. CircNRIP1 was upregulated in TAD patients and Ang II-induced HA-VSMCs. Knockdown of circNRIP1 suppressed Ang II-induced proliferation, migration and phenotypic switch of HA-VSMCs. Also, high expression of CXCL5 was observed in TAD patients, and its knockdown could inhibit Ang II-induced HA-VSMCs proliferation, migration and phenotypic switch. Moreover, CXCL5 overexpression reversed the regulation of circNRIP1 knockdown on Ang II-induced HA-VSMCs functions. Mechanistically, circNRIP1 could competitively bind to IGF2BP1 and subsequently enhance CXCL5 mRNA stability. CircNRIP1 might contribute to TAD progression by promoting CXCL5 mRNA stability via recruiting IGF2BP1.

Angiopoietin-like 4 facilitates human aortic smooth muscle cell phenotype switch and dysfunctions through the PI3K/Akt signaling in aortic dissection

PURPOSE

Vascular smooth muscle cell (VSMC) phenotype switch and dysfunctions have been reported to participate in aortic dissection (AD) progression. This study was aimed to investigate the role of angiopoietin-like 4 (ANGPTL4) in regulating VSMCs phenotype switch.

MATERIALS AND METHODS

Key genes were analyzed in AD using public datasets, and it was found that the central differential gene ANGPTL4 was up-regulated in AD. The KEGG signaling pathway annotation was performed to validate the associated pathways, and the expression of ANGPTL4 was verified using multiple datasets and clinical samples. Furthermore, the specific functions of ANGPTL4 on platelet-derived growth factor-BB (PDGF-BB)-treated human aortic smooth muscle cell (HASMC) phenotypes were investigated. The dynamic effects of ANGPTL4 and core signaling antagonists on HASMC phenotypes were examined.

RESULTS

Hub gene ANGPTL4 was significantly up-regulated in AD. ANGPTL4 was linked to the PI3K/Akt signaling, angiogenesis, and neovascularization and remodeling. ANGPTL4 overexpression further enhanced PDGF-BB effects on HASMC phenotypes, including promoted cell viability and migration, decreased contractile VSMC markers α-SMA and SM22α, elevated ECM degradation markers MMP-2 and MMP-9, and promoted phosphorylation of PI3K and Akt. ANGPTL4 knockdown partially abolished PDGF-BB-induced contractile/synthetic VSMCs imbalance and HASMC dysfunctions. Furthermore, in ANGPTL4-overexpressing HASMCs pre-treated with PDGF-BB, the PI3K/Akt signaling inhibitor LY294002 also partially eliminated the effects caused by the PDGF-BB treatment and ANGPTL4 overexpression.

CONCLUSIONS

ANGPTL4 is significantly up-regulated in AD. ANGPTL4 overexpression further enhanced PDGF-BB effects on HASMC phenotype switch and dysfunctions, which might be involved in the PI3K/Akt signaling.

Inhibition of ANGPTL8 protects against diabetes-associated cognitive dysfunction by reducing synaptic loss via the PirB signaling pathway

BACKGROUND

Type 2 diabetes mellitus (T2D) is associated with an increased risk of cognitive dysfunction. Angiopoietin-like protein 8 (ANGPTL8) is an important regulator in T2D, but the role of ANGPTL8 in diabetes-associated cognitive dysfunction remains unknown. Here, we explored the role of ANGPTL8 in diabetes-associated cognitive dysfunction through its interaction with paired immunoglobulin-like receptor B (PirB) in the central nervous system.

METHODS

The levels of ANGPTL8 in type 2 diabetic patients with cognitive dysfunction and control individuals were measured. Mouse models of diabetes-associated cognitive dysfunction were constructed to investigate the role of ANGPTL8 in cognitive function. The cognitive function of the mice was assessed by the Barnes Maze test and the novel object recognition test, and levels of ANGPTL8, synaptic and axonal markers, and pro-inflammatory cytokines were measured. Primary neurons and microglia were treated with recombinant ANGPTL8 protein (rA8), and subsequent changes were examined. In addition, the changes induced by ANGPTL8 were validated after blocking PirB and its downstream pathways. Finally, mice with central nervous system-specific knockout of Angptl8 and PirB-/- mice were generated, and relevant in vivo experiments were performed.

RESULTS

Here, we demonstrated that in the diabetic brain, ANGPTL8 was secreted by neurons into the hippocampus, resulting in neuroinflammation and impairment of synaptic plasticity. Moreover, neuron-specific Angptl8 knockout prevented diabetes-associated cognitive dysfunction and neuroinflammation. Mechanistically, ANGPTL8 acted in parallel to neurons and microglia via its receptor PirB, manifesting as downregulation of synaptic and axonal markers in neurons and upregulation of proinflammatory cytokine expression in microglia. In vivo, PirB-/- mice exhibited resistance to ANGPTL8-induced neuroinflammation and synaptic damage.

CONCLUSION

Taken together, our findings reveal the role of ANGPTL8 in the pathogenesis of diabetes-associated cognitive dysfunction and identify the ANGPTL8-PirB signaling pathway as a potential target for the management of this condition.

Murine double minute 2-mediated estrogen receptor 1 degradation activates macrophage migration inhibitory factor to promote vascular smooth muscle cell dedifferentiation and oxidative stress during thoracic aortic aneurysm progression

Estrogen receptor 1 (ESR1) has been recently demonstrated as a potential diagnostic biomarker for thoracic aortic aneurysm (TAA). However, its precise role in the progression of TAA remains unclear. In this study, TAA models were established in ApoE-knockout mice and primary mouse vascular smooth muscle cells (VSMCs) through treatment with angiotensin (Ang) II. Our findings revealed a downregulation of ESR1 in Ang II-induced TAA mice and VSMCs. Upregulation of ESR1 mitigated expansion and cell apoptosis in the mouse aorta, reduced pathogenetic transformation of VSMCs, and reduced inflammatory infiltration and oxidative stress both in vitro and in vivo. Furthermore, we identified macrophage migration inhibitory factor (MIF) as a biological target of ESR1. ESR1 bound to the MIF promoter to suppress its transcription. Artificial MIF restoration negated the mitigating effects of ESR1 on TAA. Additionally, we discovered that murine double minute 2 (MDM2) was highly expressed in TAA models and mediated protein degradation of ESR1 through ubiquitination modification. Silencing of MDM2 reduced VSMC dedifferentiation and suppressed oxidative stress. However, these effects were reversed upon further silencing of ESR1. In conclusion, this study demonstrates that MDM2 activates MIF by mediating ESR1 degradation, thus promoting VSMC dedifferentiation and oxidative stress during TAA progression.

Biomarkers in aortic dissection: Diagnostic and prognostic value from clinical research

ABSTRACT

Aortic dissection is a life-threatening condition for which diagnosis mainly relies on imaging examinations, while reliable biomarkers to detect or monitor are still under investigation. Recent advances in technologies provide an unprecedented opportunity to yield the identification of clinically valuable biomarkers, including proteins, ribonucleic acids (RNAs), and deoxyribonucleic acids (DNAs), for early detection of pathological changes in susceptible patients, rapid diagnosis at the bedside after onset, and a superior therapeutic regimen primarily within the concept of personalized and tailored endovascular therapy for aortic dissection.

Macrophage in Sporadic Thoracic Aortic Aneurysm and Dissection: Potential Therapeutic and Preventing Target

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening cardiovascular disorder lacking effective clinical pharmacological therapies. The underlying molecular mechanisms of TAAD still remain elusive with participation of versatile cell types and components including endothelial cells (ECs), smooth muscle cells (SMCs), fibroblasts, immune cells, and the extracellular matrix (ECM). The main pathological features of TAAD include SMC dysfunction, phenotypic switching, and ECM degradation, which is closely associated with inflammation and immune cell infiltration. Among various types of immune cells, macrophages are a distinct participator in the formation and progression of TAAD. In this review, we first highlight the important role of inflammation and immune cell infiltration in TAAD. Furthermore, we discuss the role of macrophages in TAAD from the aspects of macrophage origination, classification, and functions. On the basis of experimental and clinical studies, we summarize key regulators of macrophages in TAAD. Finally, we review how targeting macrophages can reduce TAAD in murine models. A better understanding of the molecular and cellular mechanisms of TAAD may provide novel insights into preventing and treating the condition.

Angiopoietin-Like Proteins: Cardiovascular Biology and Therapeutic Targeting for the Prevention of Cardiovascular Diseases

Despite the best pharmacologic tools available, cardiovascular diseases (CVDs) remain a major cause of morbidity and mortality in developed countries. After 2 decades of research, new therapeutic targets, such as angiopoietin-like proteins (ANGPTLs), are emerging. ANGPTLs belong to a family of 8 members, from ANGPTL1 to ANGPTL8; they have structural homology with angiopoietins and are secreted in the circulation. ANGPTLs display a multitude of physiological and pathologic functions; they contribute to inflammation, angiogenesis, cell death, senescence, hematopoiesis, and play a role in repair, maintenance, and tissue homeostasis. ANGPTLs-particularly the triad ANGPTL3, 4, and 8-have an established role in lipid metabolism through the regulation of triacylglycerol trafficking according to the nutritional status. Some ANGPTLs also contribute to glucose metabolism. Therefore, dysregulation in ANGPTL expression associated with abnormal circulating levels are linked to a plethora of CVD and metabolic disorders including atherosclerosis, heart diseases, diabetes, but also obesity and cancers. Because ANGPTLs bind to different receptors according to the cell type, antagonists are therapeutically inadequate. Recently, direct inhibitors of ANGPTLs, mainly ANGPTL3, have been developed, and specific monoclonal antibodies and antisense oligonucleotides are currently being tested in clinical trials. The aim of the current review is to provide an up-to-date preclinical and clinical overview on the function of the 8 members of the ANGPTL family in the cardiovascular system, their contribution to CVD, and the therapeutic potential of manipulating some of them.

Diagnostic biomarkers and aortic dissection: a systematic review and meta-analysis

BACKGROUND

Aortic dissection (AD) is a serious and fatal vascular disease. The earlier the condition of AD patients can be assessed precisely, the more scientifically controlled the patient's condition will be. Therefore, timely and accurate diagnosis is significant for AD. Blood biomarker testing as a method of liquid biopsy can improve the diagnostic efficiency of AD. This study conducted a systematic review of the current blood diagnostic biomarkers of AD.

METHODS

The PubMed, Cochrane Library, Web of Science, and Embase electronic databases were systematically searched from inception to January 1, 2023, using the terms "aortic dissection", "serum", "plasma" and "diagnosis". Stata 12.0 software was used to perform Random effects meta-analysis was performed using Stata 12.0 software to determine the effect sizes and corresponding 95% confidence intervals. Then, a summary receiver operator characteristic (SROC) curve was drawn, and the area under the ROC curve (AUC) was calculated.

RESULTS

D-dimer had the best sensitivity and AUC for AD, with values of 0.96 (95% CI: 0.93-0.98) and 0.95 (95% CI: 0.93-0.97), respectively. The sensitivity and AUC values for D-dimer with a cut-off value of 500 ng/mL were 0.97 (95% CI: 0.95-0.99) and 0.94 (95% CI: 0.92-0.96), respectively. In contrast, microRNA had a better specificity value for AD, at 0.79 (95% CI: 0.73-0.83).

CONCLUSIONS

D-dimer and microRNA have good accuracy in the diagnosis of AD, but the specificity of D-dimer is worse, and studies of microRNA are insufficient. The combination of different biomarkers can improve the diagnostic accuracy. Other blood biomarkers are related to the pathological progression of AD and can be selected according to pathological progress.

Vascular smooth muscle cells specific deletion of angiopoietin-like protein 8 prevents angiotensin II-promoted hypertension and cardiovascular hypertrophy

AIMS

Angiopoietin-like protein 8 (ANGPTL8) plays important roles in lipid metabolism, glucose metabolism, inflammation, and cell proliferation and migration. Clinical studies have indicated that circulating ANGPTL8 concentrations are increased in patients with hypertension and positively associated with blood pressure. ANGPTL8 deficiency ameliorates blood pressure in mice treated with chronic intermittent hypoxia. Currently, little is known regarding the pathophysiological role of the vascular smooth muscle cell (VSMC)-derived ANGPTL8 in hypertension and hypertensive cardiovascular remodelling.

METHODS AND RESULTS

Circulating ANGPTL8 concentrations, as determined by enzyme-linked immunosorbent assay, were significantly higher in hypertensive patients than in controls (524.51 ± 26.97 vs. 962.92 ± 15.91 pg/mL; P < 0.001). In hypertensive mice [angiotensin II (AngII) treatment for 14 days] and spontaneously hypertensive rats, ANGPTL8 expression was increased and predominantly located in VSMCs. In AngII-treated mice, systolic and diastolic blood pressure in Tagln-Cre-ANGPTL8fl/fl mice were approximately 15-25 mmHg lower than that in ANGPTL8fl/fl mice. AngII-induced vascular remodelling, vascular constriction, and increased expression of cell markers of proliferation (PCNA and Ki67) and migration (MMP-2 and MMP-9) were strikingly attenuated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. Furthermore, the AngII-induced increase in the heart size, heart weight, heart/body weight ratio, cardiomyocyte cross-sectional area, and collagen deposition was ameliorated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. In rat artery smooth muscle cells, ANGPTL8-short hairpin RNA decreased intracellular calcium levels and prevented AngII-induced proliferation and migration through the PI3K-Akt pathway, as shown using LY294002 (inhibitor of PI3K) and Akt inhibitor VIII.

CONCLUSION

This study suggests that ANGPTL8 in VSMCs plays an important role in AngII-induced hypertension and associated cardiovascular remodelling. ANGPTL8 may be a novel therapeutic target against pathological hypertension and hypertensive cardiovascular hypertrophy.

LILRB2/PirB mediates macrophage recruitment in fibrogenesis of nonalcoholic steatohepatitis

Inhibition of immunocyte infiltration and activation has been suggested to effectively ameliorate nonalcoholic steatohepatitis (NASH). Paired immunoglobulin-like receptor B (PirB) and its human ortholog receptor, leukocyte immunoglobulin-like receptor B (LILRB2), are immune-inhibitory receptors. However, their role in NASH pathogenesis is still unclear. Here, we demonstrate that PirB/LILRB2 regulates the migration of macrophages during NASH by binding with its ligand angiopoietin-like protein 8 (ANGPTL8). Hepatocyte-specific ANGPTL8 knockout reduces MDM infiltration and resolves lipid accumulation and fibrosis progression in the livers of NASH mice. In addition, PirB^-/- bone marrow (BM) chimeras abrogate ANGPTL8-induced MDM migration to the liver. And yet, PirB ectodomain protein could ameliorate NASH by sequestering ANGPTL8. Furthermore, LILRB2-ANGPTL8 binding-promoted MDM migration and inflammatory activation are also observed in human peripheral blood monocytes. Taken together, our findings reveal the role of PirB/LILRB2 in NASH pathogenesis and identify PirB/LILRB2-ANGPTL8 signaling as a potential target for the management or treatment of NASH.

ANGPTL8 deletion attenuates abdominal aortic aneurysm formation in ApoE-/- mice

Angiopoietin-like protein 8 (ANGPTL8) plays important roles in lipid metabolism, glucose metabolism, inflammation, and cell proliferation and migration. Clinical studies have indicated that circulating ANGPTL8 levels are increased in patients with thoracic aortic dissection (TAD). TAD shares several risk factors with abdominal aortic aneurysm (AAA). However, the role of ANGPTL8 in AAA pathogenesis has never been investigated. Here, we investigated the effect of ANGPTL8 knockout on AAA in ApoE-/- mice. ApoE-/-ANGPTL8-/- mice were generated by crossing ANGPTL8-/- and ApoE-/- mice. AAA was induced in ApoE-/- using perfusion of angiotensin II (AngII). ANGPTL8 was significantly up-regulated in AAA tissues of human and experimental mice. Knockout of ANGPTL8 significantly reduced AngII-induced AAA formation, elastin breaks, aortic inflammatory cytokines, matrix metalloproteinase expression, and smooth muscle cell apoptosis in ApoE-/- mice. Similarly, ANGPTL8 sh-RNA significantly reduced AngII-induced AAA formation in ApoE-/- mice. ANGPTL8 deficiency inhibited AAA formation, and ANGPTL8 may therefore be a potential therapeutic target for AAA.

Dual role of ANGPTL8 in promoting tumor cell proliferation and immune escape during hepatocarcinogenesis

The interplay between hepatocellular carcinoma (HCC) cells and the tumor microenvironment is essential for hepatocarcinogenesis, but their contributions to HCC development are incompletely understood. We assessed the role of ANGPTL8, a protein secreted by HCC cells, in hepatocarcinogenesis and the mechanisms through which ANGPTL8 mediates crosstalk between HCC cells and tumor-associated macrophages. Immunohistochemical, Western blotting, RNA-Seq, and flow cytometry analyses of ANGPTL8 were performed. A series of in vitro and in vivo experiments were conducted to reveal the role of ANGPTL8 in the progression of HCC. ANGPTL8 expression was positively correlated with tumor malignancy in HCC, and high ANGPTL8 expression was associated with poor overall survival (OS) and disease-free survival (DFS). ANGPTL8 promoted HCC cell proliferation in vitro and in vivo, and ANGPTL8 KO inhibited the development of HCC in both DEN-induced and DEN-plus-CCL4-induced mouse HCC tumors. Mechanistically, the ANGPTL8-LILRB2/PIRB interaction promoted polarization of macrophages to the immunosuppressive M2 phenotype in macrophages and recruited immunosuppressive T cells. In hepatocytes, ANGPTL8-mediated stimulation of LILRB2/PIRB regulated the ROS/ERK pathway and upregulated autophagy, leading to the proliferation of HCC cells. Our data support the notion that ANGPTL8 has a dual role in promoting tumor cell proliferation and immune escape during hepatocarcinogenesis.

Angiopoietin-like protein 8 deficiency attenuates thoracic aortic aneurysm/dissection development in β-aminopropionitrile monofumarate-induced model mice

Thoracic aortic aneurysm/dissection (TAAD) is a life-threatening cardiovascular disorder. Endoplasmic reticulum stress (ERS) and vascular smooth muscle cell (VSMC) apoptosis are involved in TAAD progression. The Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) pathway is associated with VSMC apoptosis. Serum Angiopoietin-Like Protein 8 (ANGPTL8) levels are associated with aortic diameter and rupture rate of TAAD. However, a direct role of ANGPTL8 in TAAD has not been determined. β-Aminopropionitrile monofumarate (BAPN) was used to induce TAAD in C57BL/6 mice. ANGPTL8 knockout mice were used to detect the effects of ANGPTL8 on TAAD development. ANGPTL8knockdown in vitro was used to analyze the role of ANGPTL8 in VSMCs and ERS. In addition, over-expression of ANGPTL8 in VSMCs and a PERK inhibitor were used to assess the effect of ANGPTL8 on the PERK pathway. ANGPTL8 levels were increased in the aortic wall and VSMCs of BAPN-induced TAAD mice. Compared with BAPN-treated wild-type mice, ANGPTL8 knockout significantly reduced the rupture rate of TAAD to 0 %. In addition, the protein levels of proinflammatory cytokines and matrix metalloproteinase 9 (MMP9) and ERS proteins were decreased in the aorta wall. Angptl8 shRNA decreased MMP9 and ERS protein levels in VSMCs in vitro. Overexpression of ANGPTL8 significantly increased the levels of ERS proteins and MMPs, while a PERK inhibitor significantly decreased the effects of ANGPTL8 in VSMCs. ANGPTL8 contributed to TAAD development by inducing ERS activation and degradation of extracellular matrix in the aorta wall. Inhibition of ANGPTL8 may therefore represent a new strategy for TAAD therapy.

Applying multi-omics techniques to the discovery of biomarkers for acute aortic dissection

Acute aortic dissection (AAD) is a cardiovascular disease that manifests suddenly and fatally. Due to the lack of specific early symptoms, many patients with AAD are often overlooked or misdiagnosed, which is undoubtedly catastrophic for patients. The particular pathogenic mechanism of AAD is yet unknown, which makes clinical pharmacological therapy extremely difficult. Therefore, it is necessary and crucial to find and employ unique biomarkers for Acute aortic dissection (AAD) as soon as possible in clinical practice and research. This will aid in the early detection of AAD and give clear guidelines for the creation of focused treatment agents. This goal has been made attainable over the past 20 years by the quick advancement of omics technologies and the development of high-throughput tissue specimen biomarker screening. The primary histology data support and add to one another to create a more thorough and three-dimensional picture of the disease. Based on the introduction of the main histology technologies, in this review, we summarize the current situation and most recent developments in the application of multi-omics technologies to AAD biomarker discovery and emphasize the significance of concentrating on integration concepts for integrating multi-omics data. In this context, we seek to offer fresh concepts and recommendations for fundamental investigation, perspective innovation, and therapeutic development in AAD.

Energy Homeostasis Gene Nucleotide Variants and Survival of Hemodialysis Patients-A Genetic Cohort Study

Background: Patients undergoing hemodialysis (HD) therapy have an increased risk of death compared to the general population. We investigated whether selected single nucleotide variants (SNVs) involved in glucose and lipid metabolism are associated with mortality risk in HD patients. Methods: The study included 805 HD patients tested for 11 SNVs in FOXO3, IGFBP3, FABP1, PCSK9, ANGPTL6, and DOCK6 using HRM analysis and TaqMan assays. FOXO3, IGFBP3, L-FABP, PCSK9, ANGPTL6, and ANGPTL8 plasma concentrations were measured by ELISA in 86 individuals. The Kaplan–Meier method and Cox proportional hazards models were used for survival analyses. Results: We found out that the carriers of a C allele in ANGPTL6 rs8112063 had an increased risk of all-cause, cardiovascular, and cardiac mortality. In addition, the C allele of DOCK6 rs737337 was associated with all-cause and cardiac mortality. The G allele of DOCK6 rs17699089 was correlated with the mortality risk of patients initiating HD therapy. The T allele of FOXO3 rs4946936 was negatively associated with cardiac and cardiovascular mortality in HD patients. We observed no association between the tested proteins’ circulating levels and the survival of HD patients. Conclusions: The ANGPTL6 rs8112063, FOXO3 rs4946936, DOCK6 rs737337, and rs17699089 nucleotide variants are predictors of survival in patients undergoing HD.

ANGPTL8 accelerates liver fibrosis mediated by HFD-induced inflammatory activity via LILRB2/ERK signaling pathways

INTRODUCTION

High calorie intake is known to induce nonalcoholic fatty liver disease (NAFLD) by promoting chronic inflammation. However, the mechanisms are poorly understood.

OBJECTIVES

This study examined the roles of ANGPTL8 in the regulation of NAFLD-associated liver fibrosis progression induced by high fat diet (HFD)-mediated inflammation.

METHODS

The ANGPTL8 concentration was measured in serum samples from liver cancer and liver cirrhosis patients. ANGPTL8 knockout mice were used to induce disease models (HFD, HFHC and CCL4) followed by pathological staining, western blot and immunohistochemistry. Hydrodynamic injection of an adeno-associated virus 8 (AAV8) was used to establish a model for restoring ANGPTL8 expression specifically in ANGPTL8 KO mice livers. RNA-sequencing, protein array, Co-IP, etc. were used to study ANGPTL8's mechanisms in regulating liver fibrosis progression, and drug screening was used to identify an effective inhibitor of ANGPTL8 expression.

RESULTS

ANGPTL8 level is associated with liver fibrogenesis in both cirrhosis and hepatocellular carcinoma patients. Mouse studies demonstrated that ANGPTL8 deficiency suppresses HFD-stimulated inflammatory activity, hepatic steatosis and liver fibrosis. The AAV-mediated restoration of liver ANGPTL8 expression indicated that liver-derived ANGPTL8 accelerates HFD-induced liver fibrosis. Liver-derived ANGPTL8, as a proinflammatory factor, activates HSCs (hepatic stellate cells) by interacting with the LILRB2 receptor to induce ERK signaling and increase the expression of genes that promote liver fibrosis. The FDA-approved drug metformin, an ANGPTL8 inhibitor, inhibited HFD-induced liver fibrosis in vivo.

CONCLUSIONS

Our data support that ANGPTL8 is a proinflammatory factor that accelerates NAFLD-associated liver fibrosis induced by HFD. The serum ANGPTL8 level may be a potential and specific diagnostic marker for liver fibrosis, and targeting ANGPTL8 holds great promise for developing innovative therapies to treat NAFLD-associated liver fibrosis.

Tracking an Elusive Killer: State of the Art of Molecular-Genetic Knowledge and Laboratory Role in Diagnosis and Risk Stratification of Thoracic Aortic Aneurysm and Dissection

The main challenge in diagnosing and managing thoracic aortic aneurysm and dissection (TAA/D) is represented by the early detection of a disease that is both deadly and “elusive”, as it generally grows asymptomatically prior to rupture, leading to death in the majority of cases. Gender differences exist in aortic dissection in terms of incidence and treatment options. Efforts have been made to identify biomarkers that may help in early diagnosis and in detecting those patients at a higher risk of developing life-threatening complications. As soon as the hereditability of the TAA/D was demonstrated, several genetic factors were found to be associated with both the syndromic and non-syndromic forms of the disease, and they currently play a role in patient diagnosis/prognosis and management-guidance purposes. Likewise, circulating biomarker could represent a valuable resource in assisting the diagnosis, and several studies have attempted to identify specific molecules that may help with risk stratification outside the emergency department. Even if promising, those data lack specificity/sensitivity, and, in most cases, they need more testing before entering the “clinical arena”. This review summarizes the state of the art of the laboratory in TAA/D diagnostics, with particular reference to the current and future role of molecular-genetic testing.

ANGPTL8 is a negative regulator in pathological cardiac hypertrophy

Pathological cardiac hypertrophy is an independent risk factor for heart failure and is considered a target for the treatment of heart failure. However, the mechanisms underlying pathological cardiac hypertrophy remain largely unknown. We aimed to investigate the role of angiopoietin-like protein 8 (ANGPTL8) in pathological cardiac hypertrophy. We found that serum ANGPTL8 levels were significantly increased in hypertensive patients with cardiac hypertrophy and in mice with cardiac hypertrophy induced by Ang II or TAC. Furthermore, the secretion of ANGPTL8 from the liver was increased during hypertrophic processes, which were triggered by Ang II. In the Ang II- and transverse aortic constriction (TAC)-induced mouse cardiac hypertrophy model, ANGPTL8 deficiency remarkably accelerated cardiac hypertrophy and fibrosis with deteriorating cardiac dysfunction. Accordingly, both recombinant human full-length ANGPTL8 (rANGPTL8) protein and ANGPTL8 overexpression significantly mitigated Ang II-induced cell enlargement in primary neonatal rat cardiomyocytes (NRCMs) and H9c2 cells. Mechanistically, the antihypertrophic effects of ANGPTL8 depended on inhibiting Akt and GSK-3β activation, and the Akt activator SC-79 abolished the antihypertrophic effects of rANGPTL8 in vitro. Moreover, we demonstrated that ANGPTL8 directly bound to the paired Ig-like receptor PIRB (LILRB3) by RNA-seq and immunoprecipitation-mass screening. Remarkably, the antihypertrophic effects of ANGPTL8 were largely blocked by anti-LILRB3 and siRNA-LILRB3. Our study indicated that ANGPTL8 served as a novel negative regulator of pathological cardiac hypertrophy by binding to LILRB3 (PIRB) and inhibiting Akt/GSK3β activation, suggesting that ANGPTL8 may provide synergistic effects in combination with AT1 blockers and become a therapeutic target for cardiac hypertrophy and heart failure.

The Effect of Rosuvastatin on Plasma/Serum Levels of High-Sensitivity C-Reactive Protein, Interleukin-6, and D-Dimer in People Living with Human Immunodeficiency Virus: A Systematic Review and Meta-Analysis

Rosuvastatin therapy might have an effect on the inflammatory and coagulation biomarkers. However, the evidence about the effect of rosuvastatin therapy on the high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and D-dimer levels among people living with human immunodeficiency virus (PLHIV) is still unclear. Therefore, this study investigated the relational effect of rosuvastatin therapy on serum/plasma hsCRP, IL-6 and D-dimer levels in PLHIV. The literature search was done from Embase, PubMed, and Web of Science databases. The review and meta-analysis included studies written in English language up to January 4, 2020. Random effects model was used to evaluate the pooled standard mean difference with 95% confidence interval. A meta-analysis was performed using nine articles with 392 PLHIV. The result revealed that the plasma/serum levels of IL-6 were significantly reduced after the intervention. However, hsCRP and D-dimer levels showed no significant difference (p > .05) between before and after the intervention. The subgroup analysis showed that there was significant association between PLHIV ages <45 years and cohort studies with IL-6 levels. The current CD4⁺ counts ≥350 cells/mm³ correlated with hsCRP as well as IL-6. Similarly, nadir CD4⁺ counts ≥200 cells/mm³ and duration of HIV diagnosis <10 years also showed significant association with IL-6 and D-dimer levels. It was also indicated that participants who were under antiretroviral drug for <7 years were significantly associated with hsCRP levels. This study established that IL-6 levels were significantly reduced after the intervention while hsCRP and D-dimer levels showed no significant difference between before and after the intervention.

Analysis of the Expression and Prognostic Potential of a Novel Metabolic Regulator ANGPTL8/Betatrophin in Human Cancers

The angiopoietin-like protein (ANGPTL) family members, except for the novel atypical member ANGPTL8/betatrophin, have been reported to participate in angiogenesis, inflammation and cancer. ANGPTL8/betatrophin is a metabolic regulator that is involved in lipid metabolism and glucose homeostasis. However, little is known about the expression and prognostic value of ANGPTL8/betatrophin in human cancers. In this study, we first conducted detailed analyses of ANGPTL8/betatrophin expression in cancer/normal samples via the Human Protein Atlas (HPA), Gene Expression Profiling Interactive Analysis (GEPIA), DriverDBv3, ENCORI and UALCAN databases. ANGPTL8/betatrophin showed high tissue specificity (enriched in the liver) and cell-type specificity (enriched in HepG2 and MCF7 cell lines). More than one databases demonstrated that the gene expression of ANGPTL8/betatrophin was significantly lower in cholangiocarcinoma (CHOL), breast invasive carcinoma (BRCA), lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), uterine corpus endometrial carcinoma (UCEC), and significantly higher in kidney renal clear cell carcinoma (KIRC) compared with that in normal samples. However, the protein expression of ANGPTL8/betatrophin displayed opposite results in clear cell renal cell carcinoma (ccRCC)/KIRC. Based on the expression profiles, the prognostic value was evaluated with the GEPIA, DriverDBv3, Kaplan Meier plotter and ENCORI databases. Two or more databases demonstrated that ANGPTL8/betatrophin significantly affected the survival of KIRC, uterine corpus endometrial carcinoma (UCEC), pheochromocytoma and paraganglioma (PCPG) and sarcoma (SARC); patients with PCPG and SARC may benifit from high ANGPTL8/betatrophin expression while high ANGPTL8/betatrophin expression was associated with poor prognosis in KIRC and UCEC. Functional analyses with the GeneMANIA, Metascape and STRING databases suggested that ANGPTL8/betatrophin was mainly involved in lipid homeostasis, especially triglyceride and cholesterol metabolism; glucose homeostasis, especially insulin resistance; AMPK signaling pathway; PI3K/Akt signaling pathway; PPAR signaling pathway; mTOR signaling pathway; HIF-1 signaling pathway; autophagy; regulation of inflammatory response. ANGPTL8/betatrophin may be a promising prognostic biomarker and therapeutic target, thus providing evidence to support further exploration of its role in defined human cancers.

Association of ANGPTL8 and Resistin With Diabetic Nephropathy in Type 2 Diabetes Mellitus

Background

Previous studies showed altered angiopoietin-like protein-8 (ANGPTL-8) and resistin circulating levels in type 2 diabetes mellitus (T2DM). Whether or not the alteration in ANGPTL-8 and resistin level can be a predictive maker for increased diabetic nephropathy risk remains unclear.

Aim

To Investigate the possible association of ANGPTL-8 and resistin with DN, and whether this association is affected by NAFLD status.

Methods

A total of 278 T2DM patients were enrolled. Serum levels of ANGPTL8, resistin, BMI, blood pressure, duration of diabetes, glycosylated hemoglobin (HbA1c), fasting blood glucose (FPG), hypersensitive C-reactive protein (hs-CRP), lipid profile, liver, and kidney function tests were assessed. The relationship between DN with ANGPTL8 and resistin was analyzed in the unadjusted and multiple-adjusted regression models.

Results

Serum levels of ANGPTL8 and resistin were significantly higher in DN compared with T2DM subjects without DN (respectively; P <0.001), especially in non-NAFLD populations. ANGPTL8 and resistin showed positive correlation with hs-CRP (respectively; P<0.01), and negative correlation with estimated GFR (eGFR) (respectively; P=<0.001) but no significant correlation to HOMA-IR(respectively; P>0.05). Analysis showed ANGPTL8 levels were positively associated with resistin but only in T2DM patients with DN(r=0.1867; P<0.05), and this significant correlation disappeared in T2DM patients without DN. After adjusting for confounding factors, both ANGPTL8(OR=2.095, 95%CI 1.253-3.502 P=0.005) and resistin (OR=2.499, 95%CI 1.484-4.208 P=0.001) were risk factors for DN. Data in non-NAFLD population increased the relationship between ANGPTL8 (OR=2.713, 95% CI 1.494-4.926 P=0.001), resistin (OR=4.248, 95% CI 2.260-7.987 P<0.001)and DN. The area under the curve (AUC) on receiver operating characteristic (ROC) analysis of the combination of ANGPTL8 and resistin was 0.703, and the specificity was 70.4%. These data were also increased in non-NAFLD population, as the AUC (95%CI) was 0.756, and the specificity was 91.2%.

Conclusion

This study highlights a close association between ANGPTL8, resistin and DN, especially in non-NAFLD populations. These results suggest that ANGPTL-8 and resistin may be risk predictors of DN.

Emerging roles of angiopoietin-like proteins in inflammation: Mechanisms and potential as pharmacological targets

Angiopoietin-like proteins (ANGPTLs), a family of eight secreted glycoproteins termed ANGTPL1-8, are involved in angiogenesis, lipid metabolism, cancer progression, and inflammation. Their roles in regulating lipid metabolism have been intensively studied, as some ANGPTLs are promising pharmacological targets for hypertriglyceridemia and associated cardiovascular disease. Recently, the emerging roles of ANGPTLs in inflammation have attracted great attention. First, elevated levels of multiple circulating ANGPTLs in inflammatory diseases make them potential disease biomarkers. Second, multiple ANGPTLs regulate acute or chronic inflammation via various mechanisms, including triggering inflammatory signaling through their action as ligands for integrin or forming homo- /hetero-oligomers to regulate signal transduction via extra- or intracellular mechanisms. As dysregulation of the inflammatory response is a critical trigger in many diseases, understanding the roles of ANGPTLs in inflammation will aid in drug/therapy development. Here, we summarize the roles, mechanisms, and potential therapeutic values for ANGPTLs in inflammation and inflammatory diseases.

Analysis of Hub Genes and the Mechanism of Immune Infiltration in Stanford Type a Aortic Dissection

Background: Stanford type A aortic dissection (AAD) is a catastrophic disease. An immune infiltrate has been found within the aortic wall of dissected aortic specimens. The recall and activation of macrophages are key events in the early phases of AAD. Herein, the immune filtration profile of AAD was uncovered.

Methods: Gene expression data from the GSE52093, GSE98770 and GSE153434 datasets were downloaded from the Gene Expression Omnibus (GEO). The differentially expressed genes (DEGs) of each dataset were calculated and then integrated. A protein-protein interaction (PPI) network was established with the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), and the hub genes were identified in Cytoscape. Furthermore, gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of hub genes were performed. Finally, we set GSE52093 and GSE98770 as the training set and GSE153434 as the validation set to assess immune infiltration in AAD using CIBERSORTx and analyzed the correlations between immune cells and hub genes in both the training and validation sets.

Results: Sixty-one integrated DEGs were identified. The top 10 hub genes were selected from the PPI network, and 140 biological process (BP) terms and 12 pathways were enriched among the top 10 hub genes. The proportions of monocytes and macrophages were significantly higher in AAD tissues than in normal tissues. Notably, this result was consistent in the training set and the validation set. In addition, we found that among the hub genes, CA9, CXCL5, GDF15, VEGFA, CCL20, HMOX1, and SPP1 were positively correlated with CD14, a cell marker of monocytes, while CA9, CXCL5, GDF15, and VEGFA were positively correlated with CD68, a cell marker of macrophages in the training set. Finally, according to the results of the GO and KEGG analysis of hub genes, we found that the monocyte/macrophage-related genes were involved in immune-inflammatory responses through degradation of the extracellular matrix, endothelial cell apoptosis, hypoxia and the interaction of cytokines and chemokines.

Conclusion: The monocyte-macrophage system plays a major role in immune-inflammatory responses in the development of AAD. Several hub genes are involved in this process via diverse mechanisms.

Diagnostic value of monocyte to high-density lipoprotein ratio in acute aortic dissection in a Chinese han population

Background: Recently, considerable evidence pointed out monocyte to high-density lipoprotein ratio (MHR) is highly related to inflammatory related diseases. We aim to explore the level of MHR in acute aortic dissection (AAD) patients and determine whether MHR can be a novel diagnostic marker of AAD. Research design and methods: A total of 228 subjects including 128 AAD patients and 110 healthy control were enrolled. MHR levels and other serum samples were obtained at admission. Results: The baseline MHR levels were significantly higher in patients with AAD (p < 0.0001). A cutoff value of MHR >0.37 was associated with a sensitivity of 86.70% and a specificity of 93.60% for AAD. MHR levels were positively correlated with the time from symptom onset (R² = 0.0318, p = 0.0003). Additionally, the area under the curve (AUC) was increased to 0.979 in patients whose time from onset of symptoms >24 h, with a sensitivity of 98.04% and a specificity of 93.64%. Multivariate logistic regression demonstrated that MHR levels, history of hypertension, and coronary artery disease (CHD) emerged as independent predictors of AAD. Expert Opinion: MHR has a high diagnostic value in AAD patients, especially in those whose time from onset of symptoms >24 h.