The Potential of Angiogenin as a Serum Biomarker for Diseases: Systematic Review and Meta-Analysis

Ribonuclease inhibitor 1 emerges as a potential biomarker and modulates inflammation and iron homeostasis in sepsis

Sepsis, marked by organ dysfunction, necessitates reliable biomarkers. Ribonuclease inhibitor 1 (RNH1), a ribonuclease (RNase) inhibitor, emerged as a potential biomarker for acute kidney injury and mortality in thoracoabdominal aortic aneurysm patients. Our study investigates RNH1 dynamics in sepsis, its links to mortality and organ dysfunction, and the interplay with RNase 1 and RNase 5. Furthermore, we explore RNH1 as a therapeutic target in sepsis-related processes like inflammation, non-canonical inflammasome activation, and iron homeostasis. We showed that RNH1 levels are significantly higher in deceased patients compared to sepsis survivors and correlate with creatine kinase, aspartate and alanine transaminase, bilirubin, serum creatinine and RNase 5, but not RNase 1. RNH1 mitigated LPS-induced TNFα and RNase 5 secretion, and relative mRNA expression of ferroptosis-associated genes HMOX1, FTH1 and HAMP in PBMCs. Monocytes were identified as the predominant type of LPS-positive PBMCs. Exogenous RNH1 attenuated LPS-induced CASP5 expression, while increasing IL-1β secretion in PBMCs and THP-1 macrophages. As RNH1 has contradictory effects on inflammation and non-canonical inflammasome activation, its use as a therapeutic agent is limited. However, RNH1 levels may play a central role in iron homeostasis during sepsis, supporting our clinical observations. Hence, RNH1 shows promise as biomarkers for renal and hepatic dysfunction and hepatocyte injury, and may be useful in predicting the outcome of septic patients.

Investigating angiogenin/ribonuclease 5 as a diagnostic biomarker for bladder cancer: In-depth analysis from a systematic review and meta-analysis

Bladder cancer (BC) represents a prevalent malignancy in North America and Europe, posing significant health burdens. The identification of a reliable biomarker for early BC detection is imperative to enhance prognostic outcomes. Our aim for this study is to determine the diagnostic accuracy and potential clinical utility of Angiogenin/Ribonuclease 5 (ANG/RNase 5) as a biomarker for detection of BC. A systematic literature search across multiple databases up to March 20, 2024, was conducted. CMA 3.7 and Meta-disk 1.4 were used to analyze specificity, sensitivity, AUC, DOR, LR+, LR-, Q*index, and SROC for ANG as a urinary biomarker in BC patients. Publication bias was assessed using Egger's regression asymmetry and Begg's rank correlation tests. Additional diagnosing analyses were performed using Python programming language version 3.12.1. In this meta-analysis of seven case-control studies comprising 1,051 participants (576 cases and 481 controls), pooled sensitivity was 0.701 (95 % CI: 0.662-0.738), specificity was 0.787 (95 % CI: 0.752-0.819), LR + was 3.582 (95 % CI: 2.260-5.676), LR- was 0.398 (95 % CI: 0.327-0.485), and DOR was 10.637 (95 % CI: 6.106-18.529). The AUC and Q* index values were 0.823 and 0.756, respectively. Both Begg and Mazumdar Rank Correlation Test (p = 0.229) and Egger's Test of the Intercept (p = 0.135) revealed no significant evidence of publication bias. Our meta-analysis confirms ANG/RNase 5 as a reliable biomarker for early bladder cancer detection, showing strong diagnostic accuracy and no publication bias.

Research progress on the structure, function, and use of angiogenin in malignant tumours

Angiogenin (ANG) is a specialised secreted ribonuclease, also known as RNase5, that is widely expressed in vertebrates. ANG dysregulation is closely associated with the development of breast, nasopharyngeal, and lung cancers. In recent years, studies have found that ANG not only induces neovascularisation by activating endothelial cells, but also plays a regulatory role in the plasticity of cancer cells. Cellular plasticity plays pivotal roles in cancer initiation, progression, migration, therapeutic resistance, and relapse. Therefore, it is a promising biomarker for cancer diagnosis, prognostic evaluation, and therapy. This review summarises the current knowledge regarding the roles and clinical applications of ANG in cancer development and progression.

Plasma proteomics of diabetic kidney disease among Asians with younger-onset type 2 diabetes

CONTEXT

Patients with younger onset of type 2 diabetes (YT2D) have increased risk for kidney failure compared to those with late onset. However, the mechanism of diabetic kidney disease (DKD) progression in this high-risk group is poorly understood.

OBJECTIVES

To identify novel biomarkers and potential causal proteins associated with DKD progression in patients with YT2D.

DESIGN AND PARTICIPANTS

Among YT2D (T2D onset age ≤ 40 years), 144 DKD progressors (cases) were matched for T2D onset age, sex, and ethnicity with 292 non-progressors (controls) and divided into discovery and validation sets. DKD progression was defined as decline of estimated glomerular filtration rate (eGFR) of 3ml/min/1.73m2 or greater or 40% decline in eGFR from baseline. 1472 plasma proteins were measured through a multiplex immunoassay that uses a proximity extension assay technology. Multivariable logistic regression was used to identify proteins associated with DKD progression. Mendelian randomization (MR) was used to evaluate causal relationship between plasma proteins and DKD progression.

RESULTS

42 plasma proteins were associated with DKD progression, independent of traditional cardio-renal risk factors, baseline eGFR and urine albumin-to-creatinine ratio (uACR). The proteins identified were related to inflammatory and remodelling biological processes. Our findings suggested angiogenin as one of the top signals (odds ratio =5.29, 95% CI 2.39-11.73, P = 4.03 × 10-5). Furthermore, genetically determined plasma angiogenin level was associated with increased odds of DKD progression.

CONCLUSION

Large-scale proteomic analysis identified novel proteomic biomarkers for DKD progression in YT2D. Genetic evidence suggest a causal role of plasma angiogenin in DKD progression.

Association of plasma angiogenin with risk of major cardiovascular events in type 2 diabetes

BACKGROUND

Angiogenin, an enzyme belonging to the ribonucleases A superfamily, plays an important role in vascular biology. Here, we sought to study the association of plasma angiogenin and major adverse cardiovascular events (MACEs) in patients with type 2 diabetes (T2D).

METHODS

This prospective study included 1083 T2D individuals recruited from a secondary hospital and a primary care facility. The primary outcome was a composite of four-point MACE (nonfatal myocardial infarction, stroke, unstable angina pectoris leading to hospitalization and cardiovascular death). Circulating angiogenin was measured by a proximity extension assay. Cox regression models were used to evaluate the association of baseline plasma angiogenin with the risk of MACE.

RESULTS

During a median follow-up of 9.3 years, 109 (10%) MACE were identified. Plasma angiogenin was significantly higher in participants with MACE than in those without MACE (P < 0.001). Doubling of plasma angiogenin concentration was associated with a 3.10-fold (95% CI 1.84-5.22) increased risk for MACE. The association was only moderately attenuated after adjustment for demographic and cardiometabolic risk factors (adjusted HR 2.38, 95% CI 1.34-4.23) and remained statistically significant after additional adjustment for estimated glomerular filtration rate (eGFR) and urinary albumin to creatinine ratio (uACR) (adjusted HR 1.90, 95% CI 1.02-3.53). A consistent outcome was obtained when plasma angiogenin was analysed as a categorical variable in tertiles.

CONCLUSIONS

Plasma angiogenin was associated with the risk of future cardiovascular events in patients with T2D and may be a promising novel biomarker for identifying high-risk T2D patients for early management.

Dual function of angiogenin-4 inducing intestinal stem cells and apoptosis

The intestinal epithelium is the first line of host defense, and its homeostasis is dependent on soluble factors that comprise the crypt niche. Antimicrobial proteins are one of the mediators to maintain gut homeostasis. Angiogenin-4 (Ang4) is a member of the ribonuclease A superfamily and plays a pivotal role in antimicrobial activity against gut microbiota. However, the functions of Ang4 within the intestinal crypt niche, particularly its involvement in the development of intestinal epithelial cells (IECs), remain unknown. Here, we demonstrate that Ang4 plays a significant role in maintaining Lgr5+ intestinal stem cells (ISCs) and induces apoptosis of IECs in a concentration-dependent manner. We revealed that Ang4 is highly expressed by Paneth cells in the small intestine, as well as regenerating islet-derived family member-4 (Reg4) expressing goblet cells in the colon, and both cell subsets highly contribute to ISC maintenance. Functional analysis using intestinal organoids revealed that Ang4 induces Wnt and Notch signaling, increases Lgr5+ stem cell expansion, and promotes organoid growth. Furthermore, high concentrations of Ang4 induced apoptosis in the IEC cell line and organoids. Collectively, we propose that Ang4 is a dual functional protein and is a novel member of the crypt niche factor that promotes the expansion of ISCs and induces apoptosis.

Angiogenin Levels and Carotid Intima-Media Thickness in Patients with Type 1 Diabetes and Metabolic Syndrome

It is well documented that in patients with type 1 diabetes (DM1), decreased levels of angiogenin are associated with the development of overt nephropathy. However, little is known about angiogenin levels and subclinical macrovascular organ damage in patients with DM1 and concomitant metabolic syndrome (MS). Therefore, we analyzed the relationship between angiogenin levels and carotid intima-media thickness (cIMT) in DM1 patients with and without MS. We found that angiogenin concentration was significantly lower in DM1 patients compared to controls, while the cIMT measurements were comparable. Exclusion of patients with MS, patients with hypertension, undergoing treatment, or cigarette smokers did not change these findings. Of note, when comparing the subgroups of DM1 patients with and without MS, there was no significant difference between angiogenin levels. However, we did note a significant difference in these levels after the exclusion of smokers. The comparison of cIMT in these subgroups showed a significant difference between the study subgroups. This difference was no longer observed when the age of the patients was taken into account. In summary, it can be concluded that metabolic syndrome in patients with type 1 diabetes does not appear to impact angiogenin levels or cIMT.

PRP of T2DM Patient Immobilized on PCL Nanofibers Stimulate Endothelial Cells Proliferation

Diabetic foot ulcers (DFU) are a common complication of Type 2 Diabetes Mellitus (T2DM). Development of bioactive wound healing covers is an important task in medicine. The use of autologous platelet-rich plasma (PRP) consisting of growth factors, cytokines and components of extracellular matrix is a perspective approach for DFU treatment, but we previously found that some T2DM PRP samples have a toxic effect on mesenchymal stem cells (MSCs) in vitro. Here, we covalently immobilized T2DM PRP proteins on polycaprolactone (PCL) nanofibers, and the growth of endothelial cells on the PCL-COOH-PRP was investigated. Additionally, the level of NO reflecting the cytotoxic effects of PRP, angiogenin, and VEGF levels were measured in T2DM PRP samples. The results showed that the application of PCL-COOH-PRP nanofibers allows to remove the cytotoxicity of T2DM PRP and to improve endothelial cell adhesion and proliferative activity. We showed that the origin of T2DM PRP (the level of PRP toxicity or presence/absence of DFU) does not influence the efficiency of cell growth on PCL-COOH-PRP, and on the level of angiogenin, vascular epidermal growth factor (VEGF) in PRP itself.

Human and mouse angiogenins: Emerging insights and potential opportunities

Angiogenin, a well-known angiogenic factor, is crucial to the angiogenesis in gastrointestinal tumors. Human angiogenin has only one gene, whereas the murine angiogenin family has extended to incorporate six genes. Evolutionary studies have suggested functional variations among murine angiogenin paralogs, even though the three-dimensional structures of angiogenin proteins are remarkably similar. In addition to angiogenesis, the ubiquitous pattern of angiogenin expression suggests a variety of functions, such as tumorigenesis, neuroprotective, antimicrobial activity, and innate immunity. Here, we comprehensively reviewed studies on the structures and functions of human and mouse angiogenins. Understanding the structure and function of angiogenins from a broader perspective could facilitate future research related to development of novel therapeutics on its biological processes, especially in gastrointestinal cancers.

The role of human ribonuclease A family in health and diseases: A systematic review

The ribonuclease A (RNase A) family is one of the best-characterized vertebrate-specific proteins. In humans, eight catalytically active RNases (numbered 1–8) have been identified and have unique tissue distributions. Apart from the digestion of dietary RNA, a broad range of biological actions, including the regulation of intra- or extra-cellular RNA metabolism as well as antiviral, antibacterial, and antifungal activities, neurotoxicity, promotion of cell proliferation, anti-apoptosis, and immunomodulatory abilities, have been recently reported for the members of this family. Based on multiple biological roles, RNases are found to participate in the pathogenic processes of many diseases, such as infection, immune dysfunction, neurodegeneration, cancer, and cardiovascular disorders. This review summarizes the available data on the human RNase A family and illustrates the significant roles of the eight canonical RNases in health and disease, for stimulating further basic research and development of ideas on the potential solutions for disease diagnosis and treatment.

tRNA-Derived Small RNAs: Novel Insights into the Pathogenesis and Treatment of Cardiovascular Diseases

tRNA-derived small RNAs (tsRNAs) are non-coding RNAs with diverse functions in various diseases. Although research on tsRNAs has focused on their roles in cancer, such as gene expression regulation to influence cancer progression and realize clinical effects, a growing number of studies are investigating the association of tsRNAs with cardiovascular diseases (CVDs), including atherosclerosis, myocardial infarction, and pulmonary hypertension. tsRNA expression varies across these diseases and could be regulated by epigenetics, tsRNA structure, and tRNA-binding proteins. tsRNAs play key roles in CVD progression, including the regulation of protein synthesis, and the different mechanisms underlying these functional roles of tsRNAs have been elucidated. Furthermore, tsRNAs are potential diagnostic biomarkers and therapeutic targets in CVDs. In this review, we summarize the biogenesis, classification, and regulation of tsRNAs and their potential application for CVD diagnosis and therapy. We also highlight the current challenges and provide perspectives for further investigation.

Angiogenesis, Lymphangiogenesis, and Inflammation in Chronic Obstructive Pulmonary Disease (COPD): Few Certainties and Many Outstanding Questions

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation, predominantly affecting the lung parenchyma and peripheral airways, that results in progressive and irreversible airflow obstruction. COPD development is promoted by persistent pulmonary inflammation in response to several stimuli (e.g., cigarette smoke, bacterial and viral infections, air pollution, etc.). Angiogenesis, the formation of new blood vessels, and lymphangiogenesis, the formation of new lymphatic vessels, are features of airway inflammation in COPD. There is compelling evidence that effector cells of inflammation (lung-resident macrophages and mast cells and infiltrating neutrophils, eosinophils, basophils, lymphocytes, etc.) are major sources of a vast array of angiogenic (e.g., vascular endothelial growth factor-A (VEGF-A), angiopoietins) and/or lymphangiogenic factors (VEGF-C, -D). Further, structural cells, including bronchial and alveolar epithelial cells, endothelial cells, fibroblasts/myofibroblasts, and airway smooth muscle cells, can contribute to inflammation and angiogenesis in COPD. Although there is evidence that alterations of angiogenesis and, to a lesser extent, lymphangiogenesis, are associated with COPD, there are still many unanswered questions.

Angiogenin Levels and Their Association with Cardiometabolic Indices Following Vitamin D Status Correction in Saudi Adults

Simple Summary

Angiogenin (ANG) is a small 123 amino acid protein which in normal growth is associated with formation of new blood vessels in a process called angiogenesis; however, the abnormal levels of this protein in blood has been associated with diseases such as cancer, neurological disorders, and cardiovascular diseases. Vitamin D deficiency and elevated levels of blood lipids have also been associated with many diseases including cardiovascular diseases. In this study, the investigators tried to evaluate the relationship between the circulating levels of ANG, vitamin D, and lipids. The model used was vitamin D supplementation of deficient Saudi adults in order to find the effect of vitamin D correction on circulating levels of ANG and blood lipids. With vitamin D supplementation, modest but non-significant elevation in ANG was observed, as well as significant increase in apolipoproteins CIII and E and significant decrease in apo B. In addition, the correlation between circulating levels of ANG and apolipoproteins especially apo E observed in this study are interesting and should be investigated more as both are linked with neurologic disorders like Alzheimer’s and Parkinson’s diseases.

Abstract

Angiogenin (ANG), a multifunctional protein known to induce blood vessel formation, is a potential biomarker for cardiovascular diseases; however, whether it is affected by vitamin D supplementation is not known. This interventional study in vitamin D-deficient Saudi adults was designed to investigate it. A total of 100 vitamin D-deficient Saudi adults aged 30–50 years were randomly selected to undergo 6-month vitamin D supplementation. Circulating levels of fasting glucose, lipids, vitamin D, apolipoproteins (AI, AII, B, CI, CII, CIII, E, and H), and ANG were measured using commercially available assays at baseline and after six months. Overall, vitamin D levels increased significantly post intervention. With this, levels of apo-CIII and apo-E significantly increased (p-values of 0.001 and 0.009, respectively) with a significant parallel decrease in apo-B (p = 0.003). ANG levels were significantly positively associated with most apolipoproteins and inversely correlated with HDL-cholesterol. Post intervention, the changes in ANG levels were positively correlated with apo-E (r = 0.32; p < 0.01 in all subjects and r = 0.40; p < 0.05 in males). Vitamin D supplementation may modestly affect ANG levels. The association observed between ANG and apo-E is worthy of further investigation since both biomarkers have been linked to neurodegenerative disorders.

Putative regulatory functions of SNPs associated with bronchial asthma, arterial hypertension and their comorbid phenotype

Linkage disequilibrium (LD) of single nucleotide polymorphisms (SNPs) of TLR4/AL160272.2 (rs1927914, rs1928298, rs7038716, rs7026297, rs7025144) was estimated in the Slavs of West Siberia. We further investigated an association of SNPs in TLR4/AL160272.2 (rs1927914, rs7038716, rs7025144), SERPINA1 (rs1980616), ATXN2/BRAP (rs11065987), IL2RB (rs2284033), NT5C2 (rs11191582), CARD8 (rs11669386), ANG/RNASE4 (rs1010461), and ABTB2/ САТ (rs2022318) genes with bronchial asthma (BA), arterial hypertension (AH) and their comorbidity. Then, the disease-associated SNPs were annotated in silico in relation to their potential regulatory functions. Strong LD was detected between rs1928298 and rs1927914, as well as rs7026297 and rs7038716 in the Slavs of West Siberia. It was found that the rs1927914 G allele of the TLR4 gene and the rs1980616 C allele of the SERPINA1 gene are associated with the predisposition to BA. These SNPs can affect binding affinity of transcription factors of the Pou and Klf4 families, as well as the expression levels of the TLR4 and SERPINA1 genes. The rs11065987 allele A of the ATXN2/BRAP genes, the rs11669386 A allele of the CARD8 gene, the rs2284033 allele G of the IL2RB gene, and the rs11191582 allele G of the NT5C2 gene were associated with the risk of AH. These variants can alter binding affinity of the Hoxa9, Irf, RORalpha1 and HMG-IY transcription factors, as well as the expression levels of the ALDH2, CARD8, NT5C2, ARL3, and SFXN2 genes in blood cells/vessels/heart, respectively. The risk of developing a comorbid phenotype of AD and AH is associated with the A allele of rs7038716 and the T allele of rs7025144 of the TLR4/AL160272.2 genes, the A allele of rs1010461 of the ANG gene and the C allele of rs2022318 of the ABTB2/CAT genes. Variants rs7038716 and rs7025144 can change the expression levels of the TLR4 gene in blood cells, while rs1010461 and rs2022318 influence the expression levels of the ANG and RNASE4 genes as well as the CAT and ABTB2 genes in blood cells, lungs/vessels/heart.

Oxaliplatin inhibits angiogenin proliferative and cell migration effects in prostate cancer cells

Angiogenin (Ang) is a potent angiogenic protein that is overexpressed in many types of cancer at concentration values correlated to the tumor aggressiveness. Here, by means of an integrated multi-technique approach based on crystallographic, spectrometric and spectroscopic analyses, we demonstrate that the anti-cancer drug oxaliplatin efficiently binds angiogenin. Microscopy cellular studies, carried out on the prostate cancer cell (PC-3) line , show that oxaliplatin inhibits the angiogenin prompting effect on cell proliferation and migration, which are typical features of angiogenesis process. Overall, our findings point to angiogenin as a possible target of oxaliplatin, thus suggesting a potential novel mechanism for the antineoplastic activity of this platinum drug and opening the avenue to novel approaches in the combined anti-cancer anti-angiogenic therapy.

Biomarkers in Acute Heart Failure Syndromes: An Update

Heart failure is one of the leading healthcare problems in the world. Clinical data lacks sensitivity and specificity in the diagnosis of heart failure. Laboratory biomarkers are a non-invasive method of assessing suspected decompensated heart failure. Biomarkers such as natriuretic peptides have shown promising results in the management of heart failure. The literature does not provide comprehensive guidance in the utilization of biomarkers in the setting of acute heart failure syndrome. Many conditions that manifest with similar pathophysiology as acute heart failure syndrome may demonstrate positive biomarkers. The following is a review of biomarkers in heart failure, enlightening their role in diagnosis, prognosis and management of heart failure.

Urinary Angiogenin as a Marker for Bladder Cancer: A Meta-Analysis

AIMS

Bladder cancer (BCa) is a common cancer in North America and Europe that carries considerable morbidity and mortality. A reliable biomarker for early detection of the bladder is crucial for improving the prognosis of BCA. In this meta-analysis, we examine the diagnostic role of the angiogenin (ANG) protein in patients' urine with bladder neoplasm.

METHODS

We performed a systematic literature search using ScienceDirect, Web of Science, PubMed/MEDLINE, Scopus, Google Scholar, and Embase, up to 10th October 2020 databases. Meta-Disc V.1.4 and Comprehensive Meta-Analysis V.2.2 software calculated the pooled specificity, sensitivity, area under the curve (AUC), diagnostic odds ratio (DOR), positive likelihood ratio (LR+), negative likelihood ratio (LR-), Q ∗ index, and summary receiver-operating characteristic (SROC) for the role of ANG as a urinary biomarker for BCa patients.

RESULTS

Four case-control studies were included with 656 participants (417 cases and 239 controls) in this meta-analysis. The pooled sensitivity of 0.71 (95% CI: 0.66-0.75), specificity of 0.78 (95% CI: 0.73-0.81), LR+ of 3.34 (95% CI: 2.02-5.53), LR- of 0.37 (95% CI: 0.32-0.44), DOR of 9.99 (95% CI: 4.69-21.28), and AUC of 0.789 and Q ∗ index of 0.726 demonstrate acceptable diagnostic precision of ANG in identifying BCa.

CONCLUSION

This meta-analysis showed that ANG could be a fair biomarker for the diagnosis of BCa patients.

Serum concentration of matrix metalloproteinases and angiogenic factors in patients with venous leg ulcers

INTRODUCTION

Leg ulcers are a frequently observed medical problem affecting 3-5% of the general population over 65 years of age. The most common factor responsible for the development of leg ulcers is chronic venous insufficiency (CVI). It is believed that during the formation of an ulcer there are two processes occurring simultaneously, extracellular matrix (ECM) degradation and angiogenesis in which several proteins including matrix metalloproteinases, angiogenic and regulatory factors are engaged.

AIM

To determine the serum concentration of matrix metalloproteinase-1 (MMP-1), -9 (MMP-9), tissue inhibitors of metalloproteinases-1 (TIMP-1), angiogenin and vascular endothelial growth factor (VEGF) in patients suffering from venous leg ulcers and in the healthy control group.

MATERIAL AND METHODS

The study group consisted of 71 Caucasians (39 patients, 32 controls). To evaluate the serum concentration of MMP-1, MMP-9, TIMP-1, VEGF and angiogenin, the ELISA technique was used.

RESULTS

Mean MMP-1 and MMP-9 concentrations in the study group were 14.16 ±2.98 and 12.45 ±3.85 ng/ml, respectively, and in controls 6.08 ±2.51 ng/ml and 6.77 ±2.41 ng/ml, respectively and both differences were statistically significant (p < 0.001). There was no significant difference between the study and the control group in TIMP-1 concentration. Mean VEGF and ANG concentrations in the study group were 589.3 ±346.2 pg/ml and 1802.0 ±415.7 pg/ml, respectively, and in controls 220.3 ±110.4 pg/ml and 1229.0 ±337.7 pg/ml, respectively and both differences were statistically significant (p < 0.001).

CONCLUSIONS

Lack of significant differences in the concentration of TIMP-1 between the control and the study group confirms that proteolysis is a hallmark of CVI, but increased concentration of VEGF and angiogenin in the study group compared to the control group shows that angiogenesis occurs simultaneously with ECM remodelling.

Angiogenin-A Proposed Biomarker for Cardiovascular Disease-Is Not Associated With Long-Term Survival in Patients With Peripheral Artery Disease

We evaluated angiogenin as a prospective biomarker in peripheral artery disease (PAD) patients with and without claudication symptoms. A pilot study suggested an elevation of angiogenin in critical limb ischemia. However, in PAD patients, the predictive value of angiogenin has not yet been evaluated. For this purpose, 342 patients with PAD (age: 69 ± 10 years, 34.5% women) were followed-up for 7 years in a cross-sectional study. Angiogenin was measured by enzyme-linked immunosorbent assay. All-cause and cardiovascular mortality were analyzed by Cox regression. Angiogenin levels were higher in men (P = .001) and were associated with patient waist-to-hip ratio (P < .001), fasting triglycerides (P = .011), and inversely with estimated glomerular filtration rate (P = .009). However, angiogenin showed no association with age, characteristics of diabetes, markers of lipid metabolism, or C-reactive protein. Angiogenin did not correlate with markers of angiogenesis such as vascular endothelial growth factor, angiopoietin-2, or tie-2. Furthermore, angiogenin was not associated with PAD Fontaine stages or with patient ankle-brachial index in addition to all-cause mortality (hazard ratio [HR] = 1.09 [95% CI: 0.89-1.34]) or cardiovascular morality (HR = 1.05 [0.82-1.35]). These results suggest that angiogenin does not provide further information regarding outcome prediction in patients with PAD.

Effects of Recombinant Angiogenin on Collagen Fiber Formation and Angiogenesis in the Dermis of Wistar Rats

Purpose

The purpose of this study was to assess the capability of recombinant angiogenin isolated from Pichia pastoris yeasts to stimulate regenerative processes in the dermis of experimental animals.

Patients and Methods

Wistar rats were administered with recombinant angiogenin intracutaneously. Morphological examination of the skin and the assessment of the proliferative activity of the epidermal cells were carried out. Additionally, cytokine production by human whole blood cells exposed to angiogenin was analyzed ex vivo.

Results

Administration of angiogenin stimulates collagen fiber formation and angiogenesis. This stimulation is tightly associated with an increase in the number of fibroblasts, an increased numerical density of dermal blood vessels and an increased density of collagen fibers; also, it activates the proliferation of basal cells. Angiogenin induces the production of MCP, IL-8, IL-6, IL-1β, TNF-α, IL-10, TGF-β, and VEGF by blood cells.

Conclusion

The results obtained indicate a broad spectrum of actions of recombinant angiogenin during regenerative processes in the basal layer of the dermis.

Tear Fluid Angiogenic Factors: Potential Noninvasive Biomarkers for Retinopathy of Prematurity Screening in Preterm Infants

Purpose

To determine the status of proangiogenic factors in the tear fluid of preterm infants with and without retinopathy of prematurity (ROP).

Methods

Preterm infants (n = 36) undergoing routine ROP screening included in the prospective study were categorized as No-ROP (n = 13, no ROP at any visits), ROP (if ROP was present at first visit; n = 18), or No-ROP to ROP (no disease at first visit, but developed ROP subsequently; n = 5). Infants with ROP were also grouped as progressing (n = 7) and regressing (n = 16) based on ROP evolution between the first and subsequent visits. Schirmer's strips were used to collect tear fluid and proangiogenic factors (VEGF, angiogenin, soluble vascular cell adhesion molecule, and fractalkine) levels (in picograms per milliliter) in tear fluid were measured by multiplex ELISA.

Results

Lower levels of VEGF (135 ± 69; mean ± standard deviation) and higher levels of angiogenin (6568 ± 4975) were observed in infants with ROP compared with infants without ROP (172.5 ± 54.0; 4139 ± 3909) at the first visit. Significantly lower levels of VEGF were observed in the No-ROP to ROP group compared with the No-ROP and ROP groups. The VEGF and angiogenin levels at the first visit were significantly lower in infants with ROP with progressing disease. Angiogenin levels negatively correlated with birth weight and gestational age in ROP. The area under the curve (AUC) and odds ratio (OR) analysis demonstrated that angiogenin/birth weight (AUC = 0.776; OR, 8.6); angiogenin/gestational age (AUC = 0.706; OR, 7.3) and Angiogenin/VEGF (AUC = 0.806; OR, 14.3) ratios were able to differentiated preterm infants with and without ROP.

Conclusions

The association between angiogenin and ROP suggests its possible role in ROP. The ratio of angiogenin level with birth weight, gestational age, and/or VEGF could serve as a potential noninvasive screening biomarker for ROP.

tRNA-Derived Small RNAs and Their Potential Roles in Cardiac Hypertrophy

Transfer RNAs (tRNAs) are abundantly expressed, small non-coding RNAs that have long been recognized as essential components of the protein translation machinery. The tRNA-derived small RNAs (tsRNAs), including tRNA halves (tiRNAs), and tRNA fragments (tRFs), were unexpectedly discovered and have been implicated in a variety of important biological functions such as cell proliferation, cell differentiation, and apoptosis. Mechanistically, tsRNAs regulate mRNA destabilization and translation, as well as retro-element reverse transcriptional and post-transcriptional processes. Emerging evidence has shown that tsRNAs are expressed in the heart, and their expression can be induced by pathological stress, such as hypertrophy. Interestingly, cardiac pathophysiological conditions, such as oxidative stress, aging, and metabolic disorders can be viewed as inducers of tsRNA biogenesis, which further highlights the potential involvement of tsRNAs in these conditions. There is increasing enthusiasm for investigating the molecular and biological functions of tsRNAs in the heart and their role in cardiovascular disease. It is anticipated that this new class of small non-coding RNAs will offer new perspectives in understanding disease mechanisms and may provide new therapeutic targets to treat cardiovascular disease.

The Tumor Suppressor TGFBR3 Blocks Lymph Node Metastasis in Head and Neck Cancer

The TGF-β type III receptor (TGFBR3) is an essential constituent of the TGF-β signaling. In this study, we observed a down-regulation of TGFBR3 in oral cancer, a subtype of head and neck cancer (HNC), and patients with low TGFBR3 had poor clinical outcomes. Ectopic expression of TGFBR3 decreased migration and invasion of oral cancer cells and lymph node metastasis of tumors, whereas depletion of TGFBR3 had the opposite effect. In SMAD4-positive OC-2 oral cancer cells, TGFBR3-mediated suppression requires both of its cytoplasmic interacting partners ARRB2 and GIPC1. We demonstrated that TGFBR3 induces the abundance of secreted angiogenin (ANG), a known pro-angiogenic factor, and ANG is essential and sufficient to mediate TGFBR3-dependent inhibition of migration and invasion of oral cancer cells. Notably, in SMAD4-deficient CAL-27 oral cancer cells, only GIPC1 is essential for TGFBR3-induced suppressive activity. Accordingly, HNC patients with low expressions of both TGFBR3 and GIPC1 had the poorest overall survival. In summary, we conclude that TGFBR3 is as a tumor suppressor via SMAD4-dependent and -independent manner in both tumor and stromal cells during oral carcinogenesis. Our study should facilitate the possibility of using TGFBR3-mediated tumor suppression for HNC treatment.

Emerging roles of novel small non-coding regulatory RNAs in immunity and cancer

The term small non-coding RNAs (ncRNAs) refers to all those RNAs that even without encoding for a protein, can play important functional roles. Transfer RNA and ribosomal RNA-derived fragments (tRFs and rRFs, respectively) are an emerging class of ncRNAs originally considered as simple degradation products, which though play important roles in stress responses, signalling, or gene expression. They control all levels of gene expression regulating transcription and translation and affecting RNA processing and maturation. They have been linked to pivotal cellular processes such as self-renewal, differentiation, and proliferation. For this reason, mis-regulation of this novel class of ncRNAs can lead to various pathological processes such as neurodegenerative and development diseases, metabolism and immune system disorders, and cancer. In this review, we summarise the classification, biogenesis, and functions of tRFs and rRFs with a special focus on their role in immunity and cancer.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

The secretion of the angiogenic and neurotrophic factor angiogenin is COPII and microtubule dependent

The RNaseA superfamily member Angiogenin (ANG) is a secreted protein involved in neovascularization, cell proliferation and stress response. Dysregulation of ANG expression is found in many cancers with poor prognosis and mutations in ANG are associated with neurodegenerative diseases. While the uptake and nuclear translocation of ANG is relatively well characterised, little is known about how it reaches the plasma membrane and its mode of secretion. We generated SH-SY5Y neuroblastoma cell lines constitutively expressing wild type (WT) Hemagglutinin (HA) epitope tagged mouse Ang1 (mAng1), and two amyotrophic lateral sclerosis associated ANG variants (C39W and K40I). Herein, we show that these cell lines secrete mAng1 into the culture media. Using small molecule inhibitors we probed the route taken between the endoplasmic reticulum and trans-Golgi network during secretion and have characterised it as COPII and microtubule dependent. In addition, we show that disruption by the PI3-kinase inhibitor wortmannin of the later stages of transit to the plasma membrane leads to mAng1 trafficking to lysosomal compartments. This suggests an autophagy dependent regulation of secretion.

Melatonin protects the heart and endothelium against high fructose corn syrup consumption-induced cardiovascular toxicity via SIRT-1 signaling

High fructose corn syrup (HFCS) has been shown to cause cardiovascular toxicity via oxidative stress and inflammation. The aim of this study is to demonstrate the protective effects of melatonin (MLT) against HFCS-induced endothelial and cardiac dysfunction via oxidative stress and inflammation. Thirty-two Sprague Dawley male rats were distributed into three groups as control, HFCS, and HFCS + MLT. HFCS form F55 was prepared as 20% fructose syrup solution and given to the rats through drinking water for 10 weeks, and MLT administrated 10 mg/kg/day orally for last 6 weeks in addition to F55. After decapitation, blood and half of the heart samples were collected for biochemical analysis and other half of the tissues for histopathological and immunohistochemical analysis. Aspartate transaminase, creatine kinase MB, lactate dehydrogenase, total oxidant status and oxidative stress index, and caspase-3 levels increased and total antioxidant status levels decreased significantly in HFCS group. MLT treatment reversed all these parameters. Histopathologically, hyperemia, endothelial cell damage and increased levels of angiogenin, C-reactive protein, inducible nitric oxide synthase, myeloperoxidase and decreased sirtuin-1 (SIRT-1) expressions were observed in HFCS group. MLT ameliorated all these changes. MLT has an anti-inflammatory, antioxidant, antiapoptotic effects on HFCS-induced cardiovascular toxicity through enhancing the expression of SIRT-1.

GPCR-Hippo Signaling in Cancer

The Hippo signaling pathway is involved in tissue size regulation and tumorigenesis. Genetic deletion or aberrant expression of some Hippo pathway genes lead to enhanced cell proliferation, tumorigenesis, and cancer metastasis. Recently, multiple studies have identified a wide range of upstream regulators of the Hippo pathway, including mechanical cues and ligands of G protein-coupled receptors (GPCRs). Through the activation related G proteins and possibly rearrangements of actin cytoskeleton, GPCR signaling can potently modulate the phosphorylation states and activity of YAP and TAZ, two homologous oncogenic transcriptional co-activators, and major effectors of the Hippo pathway. Herein, we summarize the network, regulation, and functions of GPCR-Hippo signaling, and we will also discuss potential anti-cancer therapies targeting GPCR-YAP signaling.

Angiogenin promotes colorectal cancer metastasis via tiRNA production

Metastasis of colorectal cancer (CRC) is the leading cause of CRC-associated mortality. Angiogenin (ANG), a member of the ribonuclease A superfamily, not only activates endothelial cells to induce tumor angiogenesis, but also targets tumor cells to promote cell survival, proliferation and/or migration. However, its clinical significance and underlying mechanism in CRC metastasis are still largely unknown. Here, we reported that ANG was upregulated in CRC tissues and associated with metastasis in CRC patients. We then revealed that ANG enhanced CRC growth and metastasis in both in vitro and in vivo systems. Intriguingly, we characterized a bunch of tRNA-derived stress-induced small RNAs (tiRNAs), produced through ANG cleavage, that was enriched in both CRC tumor tissues and highly metastatic cells, and functioned in ANG-promoted CRC metastasis. Moreover, higher level of a 5'-tiRNA from mature tRNA-Val (5'-tiRNA-Val) was observed in CRC patients and was correlated with tumor metastasis. Taken together, we propose that a novel ANG-tiRNAs-cell migration and invasion regulatory axis promotes CRC metastasis, which might be of potential target for CRC diagnosis and treatment.

A novel ligand-receptor relationship between families of ribonucleases and receptor tyrosine kinases

Pancreatic ribonuclease is known to participate in host defense system against pathogens, such as parasites, bacteria, and virus, which results in innate immune response. Nevertheless, its potential impact to host cells remains unclear. Of interest, several ribonucleases do not act as catalytically competent enzymes, suggesting that ribonucleases may be associated with certain intrinsic functions other than their ribonucleolytic activities. Most recently, human pancreatic ribonuclease 5 (hRNase5; also named angiogenin; hereinafter referred to as hRNase5/ANG), which belongs to the human ribonuclease A superfamily, has been demonstrated to function as a ligand of epidermal growth factor receptor (EGFR), a member of the receptor tyrosine kinase family. As a newly identified EGFR ligand, hRNase5/ANG associates with EGFR and stimulates EGFR and the downstream signaling in a catalytic-independent manner. Notably, hRNase5/ANG, whose level in sera of pancreatic cancer patients, serves as a non-invasive serum biomarker to stratify patients for predicting the sensitivity to EGFR-targeted therapy. Here, we describe the hRNase5/ANG-EGFR pair as an example to highlight a ligand-receptor relationship between families of ribonucleases and receptor tyrosine kinases, which are thought as two unrelated protein families associated with distinct biological functions. The notion of serum biomarker-guided EGFR-targeted therapies will also be discussed. Furthering our understanding of this novel ligand-receptor interaction will shed new light on the search of ligands for their cognate receptors, especially those orphan receptors without known ligands, and deepen our knowledge of the fundamental research in membrane receptor biology and the translational application toward the development of precision medicine.