Bioinformatics analysis of the microRNA genes associated with type 2 cardiorenal syndrome.

BACKGROUND: MicroRNAs (miRNAs) are important regulatory factors in the normal developmental stages of the heart and kidney. However, it is currently unclear how miRNA is expressed in type 2 cardiorenal syndrome (CRS). This study aimed to detect the differential expression of miRNAs and to clarify the main enrichment pathways of differentially expressed miRNA target genes in type 2 CRS. METHODS: Five cases of healthy control (Group 1), eight of chronic heart failure (CHF, Group 2) and seven of type 2 CRS (Group 3) were enrolled, respectively. Total RNA was extracted from the peripheral blood of each group. To predict the miRNA target genes and biological signalling pathways closely related to type 2 CRS, the Agilent miRNA microarray platform was used for miRNA profiling and bioinformatics analysis of the isolated total RNA samples. RESULTS: After the microarray analysis was done to screen for differentially expressed circulating miRNAs among the three different groups of samples, the target genes and bioinformatic pathways of the differential miRNAs were predicted. A total of 38 differential miRNAs (15 up- and 23 down-regulated) were found in Group 3 compared with Group 1, and a total of 42 differential miRNAs (11 up- and 31 down-regulated) were found in Group 3 compared to Group 2. According to the Gene Ontology (GO) function and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis, the top 10 lists of molecular functions, cellular composition and biological processes, and the top 30 signalling pathways of predicted gene targets of the differentially expressed miRNAs were discriminated among the three groups. CONCLUSION: Between the patients with CHF and type 2 CRS, miRNAs were differentially expressed. Prediction of target genes of differentially expressed miRNAs and the use of GO function and KEGG pathway analysis may reveal the molecular mechanisms of CRS. Circulating miRNAs may contribute to the diagnosis of CRS, and further and larger studies are needed to enhance the robustness of our findings.

Clinical Significance of Apela in Acute Cardiorenal Insuffiency of Chronic Heart Failure.

INTRODUCTION: Apela has a wide range of biological effects on the cardiovascular system, but the changes and significance of endogenous Apela in patients with chronic heart failure (CHF) and acute deterioration of cardiac and renal function are unclear. METHODS: A total of 69 patients with stable CHF combined with well-preserved renal function were enrolled and followed for 12 months. The effects of Apela on human renal glomerular endothelial cells (hRGEC), human glomerular mesangial cells (hMC), and human renal tubular epithelial cells (HK-2) were observed. RESULTS: Serum Apela concentration was positively correlated with NYHA class (r = 0.711) and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration (r = 0.303) but negatively correlated with left ventricular ejection fraction (LVEF) (r = -0.374) and 6-min walk distance (r = -0.860) in patients with stable CHF. Twenty-one patients experiencing deterioration of renal and cardiac function were diagnosed with cardiorenal syndrome (CRS) during the follow-up period. In addition, the serum Apela, as well as the difference in Apela between stable and worsening phases (ΔApela), was correlated with the estimated glomerular filtration rate (eGFR) and ΔeGFR in patients with CRS. Apela significantly inhibited the upregulated expression of MCP-1 and TNF-α induced by angiotensin II (AngII) in hRGEC, hMC, and HK-2 cells. Apela inhibited the adhesion of THP-1 cells to hRGEC and promoted the tubular formation of hRGEC. Moreover, Apela enhanced the expression of MMP-9 in hMC but inhibited the upregulated expression of α-SMA and vimentin in HK-2 cells by AngII. CONCLUSION: This study suggests that the level of Apela can be used to diagnose heart failure and assess the severity of cardiac dysfunction in patients with stable CHF, and its dynamic changes can be used to evaluate the damage to renal function in patients with CRS. Apela plays multiple protective effects on renal cells, highlighting its clinical application prospect in the prevention and treatment of CRS.

Reduced Apela/APJ system expression in patients with pulmonary artery hypertension secondary to chronic obstructive pulmonary disease.

BACKGROUND: Pulmonary artery hypertension (PAH) is a common disease that seriously threatens human physical and mental health. Chronic obstructive pulmonary disease (COPD) is the main cause of secondary PAH. OBJECTIVES: This study observed the differential expression of the endogenous Apela/APJ system in COPD patients with or without PAH. METHODS: A total of 69 COPD patients were enrolled, including 31 patients with PAH (COPD+PAH). Lung tissue from healthy controls, COPD patients, and COPD patients with PAH was used for RT-PCR and histological examination. RESULTS: The serum level of endogenous Apela in COPD+PAH patients was significantly lower than those in the control and COPD groups. Correlation analysis showed that systolic pulmonary artery pressure in COPD+PAH patients was negatively correlated with the serum level of endogenous Apela (r = -0.3842, p < 0.05). The percentage of intima thickening and muscularization of pulmonary arterioles was increased in COPD+PAH patients, while the expression of Apela/APJ was decreased. Compared with the healthy controls and COPD patients, the expression of endothelial markers vWF and CD34 mRNA in the pulmonary arterioles in COPD+PAH patients decreased, while the expression of interstitial markers α-SMA and vimentin mRNA was up-regulated. CONCLUSION: The present study suggests that expression of the Apela/APJ system is decreased in PAH secondary to COPD. The pathological changes involved in PAH secondary to COPD include thickening of the intima and muscularization of the pulmonary arterioles, as well as endothelial-to-mesenchymal transition. Corrective action targeting the diminished Apela/APJ system may be a promising therapeutic strategy for PAH in the future.