The level of native and oxidized lipoprotein(a) in children with nephrotic syndrome

Exploring the role of lipoprotein(a) in cardiovascular diseases and diabetes in Chinese population

A high level of lipoprotein (a) in the plasma has been associated with a variety of cardiovascular diseases and is considered to be an independent predictor of some other diseases. Based on recent studies, the concentration levels of Lp(a) in the Chinese population exhibit a distinctive variation from other populations. In the Chinese population, a high level of Lp(a) indicates a higher incidence of revascularization, platelet aggregation, and thrombogenicity following PCI. Increased risk of atherosclerotic cardiovascular disease (ASCVD) in Chinese population has been linked to higher levels of Lp(a), according to studies. More specifically, it has been found that in Chinese populations, higher levels of Lp(a) were linked to an increased risk of coronary heart disease, severe aortic valve stenosis, deep vein thrombosis in patients with spinal cord injuries, central vein thrombosis in patients receiving hemodialysis, and stroke. Furthermore, new and consistent data retrieved from several clinical trials also suggest that Lp (a) might also play an essential role in some other conditions, including metabolic syndrome, type 2 diabetes and cancers. This review explores the clinical and epidemiological relationships among Lp(a), cardiovascular diseases and diabetes in the Chinese population as well as potential Lp(a) underlying mechanisms in these diseases. However, further research is needed to better understand the role of Lp(a) in cardiovascular diseases and especially diabetes in the Chinese population.

Lipoprotein(a) and Atherosclerotic Cardiovascular Diseases: Evidence from Chinese Population

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Multiple factors are involved in CVD, and emerging data indicate that lipoprotein(a) (Lp(a)) may be associated with atherosclerotic cardiovascular disease (ASCVD) independent of other traditional risk factors. Lp(a) has been identified as a novel therapeutic target. Previous studies on the influence of Lp(a) in CVD have mainly used in western populations. In this review, the association of plasma Lp(a) concentration with ASCVD was summarized, with regards to epidemiological, population-based observational, and pathological studies in Chinese populations. Lp(a) mutations and copy number variations in Chinese populations are also explored. Finally, the impact of plasma Lp(a) levels on patients with type 2 diabetes mellitus, cancer, and familial hypercholesterolemia are discussed.

Mir-142-5p as an indicator of autoimmune processes in childhood idiopathic nephrotic syndrome and as a part of MicroRNAs expression panels for its diagnosis and prediction of response to steroid treatment

BACKGROUND

Nephrotic syndrome (NS) is the most frequent glomerular disease among children. Renal biopsy is the most precise procedure for diagnosing and following childhood NS; however, it is an invasive procedure with potential complications. As a result, early non-invasive diagnostic and prognostic indicators and new treatment targets are urgently needed for this disease.

PURPOSE

To assess the miR-142-5p expression in peripheral blood as an indicator of the autoimmune processes in children with NS and the role of differential microRNAs (miR) expression and expression panels in diagnosing and predicting the response to steroid treatment in children with NS.

METHODS

Eighty (80) children with NS and 100 subjects matched for age and gender used as controls constitute the study sample in this case-control study. MiR-142-5p, miR-191, miR-181-5p, miR-30a-5p and miR-50a-5p expression are measured in all enrolled children by real-time PCR. We assessed the sensitivity and accuracy of different MicroRNAs panels.

RESULTS

miR-142-5p, miR-191, miR-181-5p, miR-30a-5p and miR-150a-5p expressions were significantly increased in the children with NS than controls. There was a significant difference in the five mRNAs differential expressions between steroid-resistant and steroid-sensitive children with NS. Of the selected five microRNAs, miR-142a-5p was the best to allow very good discrimination of the children with NS and predict steroid resistance (AUC = 0.965 and 1.00, respectively), suggesting the possible autoimmunity processes' role in the pathogenesis of NS and the resistance to steroids. The (miR-142a-5p with miR-181a-5p and miR-30a-5p) was the best expression panel to diagnose new NS cases and predict steroid resistance.

CONCLUSIONS

microRNAs expressions, either differential or as a panel, are important for early diagnosing childhood NS and may provide a non-invasive clue for the response to steroid treatment in these patients. The (miR-142a-5p, miR-181-5p, and miR-30a-5p) panel was the best one to cover both the diagnosis of the new cases and prediction of response to steroid treatment. Autoimmunity has an important role in NS pathogenesis and resistance to steroid treatment.

Association of apoE gene polymorphisms with lipid metabolism in renal diseases

BACKGROUND AND OBJECTIVES

Apolipoprotein E (apoE) plays a central role in the metabolism and homeostasis of lipids. ApoE gene encodes three major isoforms: ε2, ε3 a nd ε4 forming six phenotypes: E2E2, E2E3, E2E4, E3E3, E3E3 and E4E4. Disorders of the lipid metabolism and the homeostasis are frequently coexist in renal diseases. The association between gene polymorphisms of apoE and lipid metabolism were not consistent. This meta-analysis was performed to assess the association between gene polymorphisms of apoE and lipid metabolism in renal diseases.

METHODS

A pre-defined literatures search and selection of eligible relevant investigations were performed to extract and collect data from electronic databases.

RESULTS

Sixteen articles were enrolled for the analysis of association between apoE gene polymorphisms and lipid metabolism. Subjects with E3E4 had a higher total cholesterol (TC) than those with E3E3, and subjects with E2E3 had a lower TC than those with E3E3. Subjects with ε2, had a lower TC than those with ε3 or ε4, and subjects with ε4 had a higher TC than those with, ε3. Subjects with E2E2, E2E3 or E4E4 had a higher triglyceride (TG) than those with E3E3. Subjects with ε4 had a higher TG than those with ε3. Subjects with ε2, had a higher level of TG than those with non-ε2. Subjects with E3E4 had a slightly lower high-density lipoprotein (HDL) than those with E3E3. E3E4 appeared to be associated with lower levels of HDL. Subjects with E2E2, E2E3 had a notably lower low-density lipoprotein (LDL) than those with E3E3. Subjects with ε2, had a lower LDL than those with ε3 or ε4 ApoE gene polymorphisms were not associated with very low-density lipoprotein, and lipoprotein (a) [Lp(a)]. Subjects with E2E3 or E2E4 had higher apoE levels than those with E3E3, and subjects with E4E4 had lower apoE levels than those with E3E3.

CONCLUSION

ApoE gene polymorphisms are associated with the expression of TC, TG HDL, LDL, Lp(a) or apoE.

Increased urinary exosomal microRNAs in children with idiopathic nephrotic syndrome

BACKGROUND

Urinary exosomal miRNAs are gaining increasing attention for their potential as ideal non-invasive biomarkers for kidney diseases; however, little is known about their diagnostic ability for paediatric nephrotic syndrome (NS). This study explored the clinical value of urinary exosomal miRNAs for paediatric idiopathic NS.

METHODS

Urine samples were collected from 129 NS children and 126 age-/sex-matched healthy controls. The miRNA profile of urinary exosomes was analysed by high-throughput Illumina sequencing via synthesis (SBS) technology followed by verification with a quantitative reverse-transcription polymerase chain reaction (RT-qPCR) assay arranged in two independent cohorts. Additionally, paired urine samples from 65 of these patients were collected before and after treatment.

FINDINGS

The Illumina SBS identified 30 markedly increased urinary exosomal miRNAs in NS children compared with controls (≥ 5-fold, P < .05). Fifteen miRNAs were selected for further investigation, of which 5 (miR-194-5p, miR-146b-5p, miR-378a-3p, miR-23b-3p and miR-30a-5p) were verified by RT-qPCR to be significantly and steadily increased in NS (> 3-fold, P < .01) and markedly reduced during the clinical remission period (P < .001). Moreover, the concentrations of miR-194-5p and miR-23b-3p were significantly positively correlated with the urine protein content and were markedly higher in the high urine protein group than in the low urine protein group (P < .001 and P < .01, respectively).

INTERPRETATIONS

We identified 5 altered urinary exosomal miRNAs in NS children with disease progression and treatment. These urinary exosomal miRNAs could be promising and non-invasive potential biomarker candidates for diagnosing, monitoring and stratifying paediatric NS. FUND: National Natural Science Foundation of China; Fund of State Key Laboratory of Analytical Chemistry for Life Science; National Basic Research Programme of China; Foundation of Jiangsu Provincial Medical Youth Talent.

Circulating microRNAs and Bioinformatics Tools to Discover Novel Diagnostic Biomarkers of Pediatric Diseases

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the post-transcriptional level. Current studies have shown that miRNAs are also present in extracellular spaces, packaged into various membrane-bound vesicles, or associated with RNA-binding proteins. Circulating miRNAs are highly stable and can act as intercellular messengers to affect many physiological processes. MicroRNAs circulating in body fluids have generated strong interest in their potential use as clinical biomarkers. In fact, their remarkable stability and the relative ease of detection make circulating miRNAs ideal tools for rapid and non-invasive diagnosis. This review summarizes recent insights about the origin, functions and diagnostic potential of extracellular miRNAs by especially focusing on pediatric diseases in order to explore the feasibility of alternative sampling sources for the development of non-invasive pediatric diagnostics. We will also discuss specific bioinformatics tools and databases for circulating miRNAs focused on the identification and discovery of novel diagnostic biomarkers of pediatric diseases.

Lipoprotein (a): impact by ethnicity and environmental and medical conditions

Levels of lipoprotein (a) [Lp(a)], a complex between an LDL-like lipid moiety containing one copy of apoB, and apo(a), a plasminogen-derived carbohydrate-rich hydrophilic protein, are primarily genetically regulated. Although stable intra-individually, Lp(a) levels have a skewed distribution inter-individually and are strongly impacted by a size polymorphism of the LPA gene, resulting in a variable number of kringle IV (KIV) units, a key motif of apo(a). The variation in KIV units is a strong predictor of plasma Lp(a) levels resulting in stable plasma levels across the lifespan. Studies have demonstrated pronounced differences across ethnicities with regard to Lp(a) levels and some of this difference, but not all of it, can be explained by genetic variations across ethnic groups. Increasing evidence suggests that age, sex, and hormonal impact may have a modest modulatory influence on Lp(a) levels. Among clinical conditions, Lp(a) levels are reported to be affected by kidney and liver diseases.

Increased serum and urinary microRNAs in children with idiopathic nephrotic syndrome

BACKGROUND

MicroRNAs (miRNAs) are present in body fluids and may have the potential to serve as disease biomarkers. This study explored the clinical value of miRNAs in serum and urine as biomarkers for idiopathic childhood nephrotic syndrome (NS).

METHODS

We obtained serum samples from 159 NS children (24 steroid resistant and 135 steroid sensitive), 109 age/sex-matched healthy controls and 44 children with other kidney diseases. Serum miRNAs were analyzed with the TaqMan Low Density Array and then validated with a quantitative reverse-transcription PCR assay with 126 individual samples. Moreover, we collected paired serum samples from 50 patients before and after treatment to determine the value of these miRNAs for condition assessment. In addition, urine samples from these patients were examined for candidate miRNAs.

RESULTS

The concentrations of serum miR-30a-5p, miR-151-3p, miR-150, miR-191, and miR-19b were highly increased in NS children compared with controls (P < 0.0001). The urinary miR-30a-5p concentration was also increased in NS (P = 0.001). The area under the ROC curve and the odds ratio for the combined 5 serum miRNAs were 0.90 (95% CI, 0.86-0.94; P < 0.0001) and 40.7 (95% CI, 6.06-103; P < 0.0001), respectively. Moreover, the concentrations of the 5 serum miRNAs and urinary miR-30a-5p markedly declined with the clinical improvement of the patients.

CONCLUSIONS

We determined that 5 distinct serum miRNAs and urinary miR-30a-5p were increased in NS children. These circulating or urinary miRNAs may represent potential diagnostic and prognostic biomarkers for idiopathic pediatric NS.