Genetic Variation in the H19-IGF2 Cluster Might Confer Risk of Developing Impaired Renal Function

LncRNA H19: a novel player in the regulation of diabetic kidney disease

Diabetic kidney disease (DKD), one of the most severe complications of diabetes mellitus (DM), has received considerable attention owing to its increasing prevalence and contribution to chronic kidney disease (CKD) and end-stage kidney disease (ESRD). However, the use of drugs targeting DKD remains limited. Recent data suggest that long non-coding RNAs (lncRNAs) play a vital role in the development of DKD. The lncRNA H19 is the first imprinted gene, which is expressed in the embryo and down-regulated at birth, and its role in tumors has long been a subject of controversy, however, in recent years, it has received increasing attention in kidney disease. The LncRNA H19 is engaged in the pathological progression of DKD, including glomerulosclerosis and tubulointerstitial fibrosis via the induction of inflammatory responses, apoptosis, ferroptosis, pyroptosis, autophagy, and oxidative damage. In this review, we highlight the most recent research on the molecular mechanism and regulatory forms of lncRNA H19 in DKD, including epigenetic, post-transcriptional, and post-translational regulation, providing a new predictive marker and therapeutic target for the management of DKD.

Serum Long Noncoding RNA H19 and CKD Progression in IgA Nephropathy

BACKGROUND

IgA nephropathy (IgAN) is one of the most common primary glomerular diseases worldwide, especially in young Asian adults. Long RNA H19 is associated with renal pathologies, such as renal cell injury; however, a connection between serum H19 expression and kidney disease progression has not been demonstrated.

METHOD

Our cohort consisted of 204 patients with IgAN. Serum H19 levels were determined with reverse-transcription quantitative polymerase between 1 May, 2014 and 1 May, 2015. H19 levels were log-transformed and categorical variables were categorized according to cutoff points of a ROC curve. Restricted cubic spline and generalized estimating equation analyses were performed to determine the association between serum H19 and kidney disease progression.

RESULTS

H19 expression was significantly downregulated in patients with IgAN compared to healthy controls. Restricted cubic spline analyses showed that the relationship was negatively and linearly correlated (P for nonlinearly = 0.256). After adjusting for other potential clinical, pathologic, and treatment factors, H19 was found to be a protective factor for prognosis in IgAN (HR, 0.52; 95% CI 0.32-0.84; P = 0.008). ROC curve analysis showed that the clinical value of lncRNA H19 with CKD and area under the ROC curve was 0.746 (95% CI 0.663-0.829; P < 0.001) of the clinical prognostic value of H19. Serum restricted cubic spline analyses showed that the relationship was negatively and linearly correlated (P for non-linearly = 0.256). H19 > 0.097 in patients in IgAN was associated with a reduction of the risk of kidney progression by approximately 70% within 5 years compared to H19≤0.097 (HR, 0.30;95% CI 0.12-0.74; P = 0.009).

CONCLUSION

H19 is an independent protective factor, and a high level of H19 often indicates better renal outcome within 5 years.

Loss of RTN3 phenocopies chronic kidney disease and results in activation of the IGF2-JAK2 pathway in proximal tubular epithelial cells

Reticulon 3 (RTN3) is an endoplasmic reticulum protein that has previously been shown to play roles in neurodegenerative diseases, but little is known about its function in the kidneys. The aim of the present study was to clarify the roles of RTN3 in chronic kidney disease (CKD) and kidney fibrosis. In this study, RTN3 levels were measured in kidney tissues from healthy controls and CKD or kidney fibrosis patients. An RTN3-null mouse model was generated to explore the pathophysiological roles of RTN3 in the kidneys. The underlying mechanisms were studied in primary proximal tubular epithelial cells and HEK293 cells in vitro. The results showed that (1) a reduction in RTN3 in mice induces CKD and kidney fibrosis; (2) decreased RTN3 expression is found in patients with CKD; (3) RTN3 plays critical roles in regulating collagen biosynthesis and mitochondrial function; and (4) mechanistically, RTN3 regulates these phenotypes by interacting with GC-Rich Promoter Binding Protein 1 (GPBP1), which activates the IGF2-JAK2-STAT3 pathway. Our study indicates that RTN3 might play crucial roles in CKD and kidney fibrosis and that a reduction in RTN3 in the kidneys might be a risk factor for CKD and kidney fibrosis.

A protein (RTN3) known to be involved in neurodegenerative diseases may play a causative role in kidney fibrosis or scarring, and chronic kidney disease (CKD). An estimated 20% of CKD cases may have genetic causes and identifying the genes involved may help find better treatments. Ri-Qiang Yan at the University of Connecticut Health, Farmington, USA, and Rong Xian at Central South University, China, noticed that mice in which the gene coding for RTN3 was inactivated had kidney fibrosis. The researchers showed that RTN3 levels were also lower in kidney tissues of patients with CKD than in healthy individuals and that RTN3 levels were inversely proportional to disease progression. Further investigation showed that decreased RTN3 caused extra collagen deposition and misshapen mitochondria, the cellular powerhouses, in the kidney. These results identify a potential novel risk factor for CKD.

Emerging role of lncRNAs in renal fibrosis

Fibrosis is the final common pathological feature of a wide variety of chronic kidney disease (CKD). However, an understanding of the mechanisms underlying the development of renal fibrosis remains challenging and controversial. As the current focus of molecular research, noncoding RNAs (ncRNAs), mainly microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular noncoding RNAs (circRNAs), have powerful and abundant biological functions, which essentially makes them mediators of the physiological and pathological processes of various system diseases. The role of ncRNAs in renal fibrosis has also received great attention in recent years, but most research has mainly focused on miRNAs. In fact, although a large number of studies of lncRNAs have emerged recently, the role these molecules play in renal fibrosis haven't been fully understood till now. Thus, this review discusses the discovery of lncRNAs and their biological functions in different types of renal fibrosis, as well as the imminent applications of these findings in clinical use. Undoubtedly, in the future, further understanding of the function of all types of lncRNAs will reveal large breakthroughs in the treatment of renal fibrosis.

Functional polymorphisms of the lncRNA H19 promoter region contribute to the cancer risk and clinical outcomes in advanced colorectal cancer

Background

The long non-coding RNA H19 plays critical roles in cancer occurrence, development, and progression. The present study is for the first time to evaluate the association of genetic variations in the H19 promoter region with advanced colorectal cancer (CRC) susceptibility, environmental factors, and clinical outcomes.

Methods

16 single-nucleotide polymorphisms (SNPs) were identified in the H19 gene promoter by DNA sequencing, and 3 SNPs among which including rs4930101, rs11042170, and rs2735970 further expanded samples with 572 advanced CRC patients and 555 healthy controls.

Results

We found that harboring SNP [rs4930101 (P = 0.009), rs2735970 (P = 0.003), and rs11042170 (P = 0.003)] or carrying more than one combined risk genotypes significantly increased the risk for CRC [P < 0.0001, adjusted OR (95% CI) 6.48 (2.97–14.15)]. In the correlation analysis with environmental factors, rs2735970 and gender, combined risk genotypes (> 1 vs. ≤ 1) and family history of cancer demonstrated significant interactions. Furthermore, a remarkably worse clinical outcome was found in combined risk genotypes (> 1 vs. ≤ 1), especially in CRC patients with body weight ≥ 61 kg, smoking, and first-degree family history of cancer (Log-rank test: P = 0.006, P = 0.018, and P = 0.013, respectively). More importantly, the multivariate Cox regression analyses further verified that combined risk genotypes > 1 showed a prognostic risk factor for CRC patients with body weight ≥ 61 kg (P = 0.002), smoking (P = 0.008), and family history of cancer (P = 0.006). In addition, MDR analysis consistently revealed that the combination of selected SNPs and nine known risk factors showed a better prediction prognosis and represented the best model to predict advanced CRC prognosis.

Conclusion

3 SNPs of rs4930101, rs11042170, and rs27359703 among 16 identified SNPs of H19 gene remarkably increased CRC risk. Furthermore, the combined risk genotypes had a significant impact on environmental factors and clinical outcomes in the advanced CRC patients with body weight ≥ 61 kg, ever-smoking, and first-degree family history of cancer. These data suggest that H19 promoter SNPs, especially these combined SNPs might be more potentially functional biomarkers in the prediction of advanced CRC risk and prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0895-x) contains supplementary material, which is available to authorized users.

Long non-coding RNA H19 is associated with polycystic ovary syndrome in Chinese women: a preliminary study

Polycystic ovary syndrome (PCOS) represents a serious reproductive and endocrine condition and is associated with high incidence rates. H19 is a compelling long noncoding RNA (lncRNA) which carries out a range of biological functions. However, prior to this study, little was known as to whether there was an association between lncRNA H19 and PCOS. In the current study, we used quantitative real-time polymerase chain reaction (qRT-PCR) to determine lncRNA H19 expression levels in peripheral blood leukocytes from patients with PCOS and compared this data with that derived from normal controls. We also screened data for potential relationships between lncRNA H19 and a range of endocrine variables in PCOS. The expression of lncRNA H19 was significantly higher in cases of PCOS than in controls. Individuals exhibiting higher expression levels of lncRNA H19 were associated with a significantly higher risk of PCOS than those with lower expression levels. Moreover, lncRNA H19 expression was positively correlated with fasting plasma glucose levels; this was the case with both raw data, and after adjustment for age and BMI in the PCOS group. However, lncRNA H19 expression showed no significant correlation with total testosterone or insulin resistance in either PCOS cases or the controls. In conclusion, we demonstrate the first evidence to indicate that lncRNA H19 is associated with PCOS, suggesting that elevated lncRNA H19 levels are a risk factor for PCOS. For susceptible individuals, lncRNA H19 may represent a useful biomarker of the early stages of endocrine and metabolic disorders in PCOS.