Transcription Factor Hepatocyte Nuclear Factor-1β (HNF-1β) Regulates MicroRNA-200 Expression through a Long Noncoding RNA

Runx2 and Polycystins in Bone Mechanotransduction: Challenges for Therapeutic Opportunities

Bone mechanotransduction is a critical process during skeletal development in embryogenesis and organogenesis. At the same time, the type and level of mechanical loading regulates bone remodeling throughout the adult life. The aberrant mechanosensing of bone cells has been implicated in the development and progression of bone loss disorders, but also in the bone-specific aspect of other clinical entities, such as the tumorigenesis of solid organs. Novel treatment options have come into sight that exploit the mechanosensitivity of osteoblasts, osteocytes, and chondrocytes to achieve efficient bone regeneration. In this regard, runt-related transcription factor 2 (Runx2) has emerged as a chief skeletal-specific molecule of differentiation, which is prominent to induction by mechanical stimuli. Polycystins represent a family of mechanosensitive proteins that interact with Runx2 in mechano-induced signaling cascades and foster the regulation of alternative effectors of mechanotransuction. In the present narrative review, we employed a PubMed search to extract the literature concerning Runx2, polycystins, and their association from 2000 to March 2024. The keywords stated below were used for the article search. We discuss recent advances regarding the implication of Runx2 and polycystins in bone remodeling and regeneration and elaborate on the targeting strategies that may potentially be applied for the treatment of patients with bone loss diseases.

Non-coding RNAs as potential biomarkers and therapeutic targets in polycystic kidney disease

Polycystic kidney disease (PKD) is a significant cause of end-stage kidney failure and there are few effective drugs for treating this inherited condition. Numerous aberrantly expressed non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs), may contribute to PKD pathogenesis by participating in multiple intracellular and intercellular functions through post-transcriptional regulation of protein-encoding genes. Insights into the mechanisms of miRNAs and other ncRNAs in the development of PKD may provide novel therapeutic strategies. In this review, we discuss the current knowledge about the roles of dysregulated miRNAs and other ncRNAs in PKD. These roles involve multiple aspects of cellular function including mitochondrial metabolism, proliferation, cell death, fibrosis and cell-to-cell communication. We also summarize the potential application of miRNAs as biomarkers or therapeutic targets in PKD, and briefly describe strategies to overcome the challenges of delivering RNA to the kidney, providing a better understanding of the fundamental advances in utilizing miRNAs and other non-coding RNAs to treat PKD.

Global alteration of colonic microRNAome landscape associated with inflammatory bowel disease

Inflammatory Bowel Disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract that associates with, among others, increased risk of colorectal cancer. There is a growing evidence that miRNAs have important roles in pathological processes, such as inflammation or carcinogenesis. Understanding the molecular mechanisms such as alterations in microRNAome upon chronic intestinal inflammation is critical for understanding the exact pathomechanism of IBD. Hence, we conducted a genome wide microRNAome analysis by applying miRNA-Seq in a rat model of experimental colitis, validated the data by QPCR, examined the expression of a selection of precursor and mature miRNAs, performed in depth biological interpretation using Ingenuity Pathway Analysis and tested the obtained results on samples derived from human patients. We identified specific, interdependent expression pattern of activator/repressor transcription factors, miRNAs and their direct targets in the inflamed colon samples. Particularly, decreased expression of the miR-200 family members (miR-200a/b/c,-141, and -429) and miR-27b correlates with the reduced level of their enhancers (HNF1B, E2F1), elevated expression of their repressors (ZEB2, NFKB1) and increased expression of their target genes (ZEB2, RUNX1). Moreover, the marked upregulation of six miR-27b target genes (IFI16, GCA, CYP1B1, RUNX1, MEF2C and MMP13) in the inflamed colon tissues is a possible direct consequence of the lack of repression due to the downregulated miRNA-27b expression. Our data indicate that changes in microRNAome are associated with the pathophysiology of IBD, consequently, microRNAs offer potential targets for the diagnosis, prognosis and treatment of IBD.

Icariin inhibits epithelial mesenchymal transition of renal tubular epithelial cells via regulating the miR-122-5p/FOXP2 axis in diabetic nephropathy rats

Epithelial mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs) dominates the pathology of diabetic nephropathy (DN). microRNAs (miRNAs) can influence the fate of DN via regulation of EMT. This study aimed to analyze the role of Icariin (ICA) in EMT of RTECs, hoping to provide theoretical basis for DN management. The DN rat model was established using streptozocin, followed by ICA treatment, histopathological observation, and detection of creatinine and blood urea nitrogen. In vitro cell models were established using high glucose (HG), followed by assessment of cell proliferation, apoptosis, and migration, and E-cadherin, α-SMA, miR-122-5p, and FOXP2 expressions. Cells were transfected with miR-122-5p mimics or si-FOXP2 for joint experiments with ICA. The targeting relationship between miR-122-5p and FOXP2 was verified. ICA repaired renal dysfunctions and glomerular structure abnormities of DN rats in a dose-dependent manner. In vitro, ICA improved proliferation while suppressed migration, apoptosis, and EMT of RTECs. miR-122-5p was up-regulated in DN rats and suppressed by ICA, and miR-122-5p targeted FOXP2. miR-122-5p up-regulation or FOXP2 down-regulation reversed the protective effects of ICA on HG-induced RTECs. Overall, our finding ascertained that ICA inhibited miR-122-5p to promote FOXP2 transcription, thereby attenuating EMT of RTECs and renal injury in DN rats.

Non-Coding RNA and Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the most common chronic microvascular complications of diabetes. In addition to the characteristic clinical manifestations of proteinuria, it also has a complex pathological process that results from the combined effects of multiple factors involving the whole renal structure such as glomeruli, renal tubules, and blood vessels. Non-coding RNAs (ncRNA) are transcripts with no or low coding potential, among which micro RNA (miRNA) has been widely studied as a functional miRNA involved in regulation and a potential biomarker for disease prediction. The abundance of long coding RNA (lncRNA) in vivo is highly expressed with a certain degree of research progress, but the structural similarity makes the research still challenging. The research of circular RNA (circRNA) is still in its early stages. It is more relevant to the study to provide a more relevant link between diseases in the kidney and other tissues or organs. This classification review mainly summarized the biogenesis characteristics, the pathological mechanism of ncRNA-regulating diseases, the ways of ncRNA in the clinical prediction as a potential biomarker, and the interaction networks of ncRNA.

Non-Coding RNAs in Hereditary Kidney Disorders

Single-gene defects have been revealed to be the etiologies of many kidney diseases with the recent advances in molecular genetics. Autosomal dominant polycystic kidney disease (ADPKD), as one of the most common inherited kidney diseases, is caused by mutations of PKD1 or PKD2 gene. Due to the complexity of pathophysiology of cyst formation and progression, limited therapeutic options are available. The roles of noncoding RNAs in development and disease have gained widespread attention in recent years. In particular, microRNAs in promoting PKD progression have been highlighted. The dysregulated microRNAs modulate cyst growth through suppressing the expression of PKD genes and regulating cystic renal epithelial cell proliferation, mitochondrial metabolism, apoptosis and autophagy. The antagonists of microRNAs have emerged as potential therapeutic drugs for the treatment of ADPKD. In addition, studies have also focused on microRNAs as potential biomarkers for ADPKD and other common hereditary kidney diseases, including HNF1β-associated kidney disease, Alport syndrome, congenital abnormalities of the kidney and urinary tract (CAKUT), von Hippel-Lindau (VHL) disease, and Fabry disease. This review assembles the current understanding of the non-coding RNAs, including microRNAs and long noncoding RNAs, in polycystic kidney disease and these common monogenic kidney diseases.

Hepatocyte nuclear factor 1β suppresses canonical Wnt signaling through transcriptional repression of lymphoid enhancer-binding factor 1

Hepatocyte nuclear factor-1β (HNF-1β) is a tissue-specific transcription factor that is required for normal kidney development and renal epithelial differentiation. Mutations of HNF-1β produce congenital kidney abnormalities and inherited renal tubulopathies. Here, we show that ablation of HNF-1β in mIMCD3 renal epithelial cells results in activation of β-catenin and increased expression of lymphoid enhancer-binding factor 1 (LEF1), a downstream effector in the canonical Wnt signaling pathway. Increased expression and nuclear localization of LEF1 are also observed in cystic kidneys from Hnf1b mutant mice. Expression of dominant-negative mutant HNF-1β in mIMCD3 cells produces hyperresponsiveness to exogenous Wnt ligands, which is inhibited by siRNA-mediated knockdown of Lef1. WT HNF-1β binds to two evolutionarily conserved sites located 94 and 30 kb from the mouse Lef1 promoter. Ablation of HNF-1β decreases H3K27 trimethylation repressive marks and increases β-catenin occupancy at a site 4 kb upstream to Lef1. Mechanistically, WT HNF-1β recruits the polycomb-repressive complex 2 that catalyzes H3K27 trimethylation. Deletion of the β-catenin-binding domain of LEF1 in HNF-1β-deficient cells abolishes the increase in Lef1 transcription and decreases the expression of downstream Wnt target genes. The canonical Wnt target gene, Axin2, is also a direct transcriptional target of HNF-1β through binding to negative regulatory elements in the gene promoter. These findings demonstrate that HNF-1β regulates canonical Wnt target genes through long-range effects on histone methylation at Wnt enhancers and reveal a new mode of active transcriptional repression by HNF-1β.

Hepatocyte nuclear factor 1 alpha influences pancreatic cancer growth and metastasis

Hepatocyte nuclear factor 1 homeobox alpha (HNF1α) is a transcription factor involved in endodermal organogenesis and pancreatic precursor cell differentiation and development. Earlier studies have reported a role for HNF1α in pancreatic ductal adenocarcinoma (PDAC) but it is controversial. The mechanism by which it impacts PDAC is yet to be explored in depth. In this study, using the online databases we observed that HNF1α is upregulated in PDAC, which was also confirmed by our immunohistochemical analysis of PDAC tissue microarray. Silencing HNF1α reduced the proliferative, migratory, invasive and colony forming capabilities of pancreatic cancer cells. Key markers involved in these processes (pPI3K, pAKT, pERK, Bcl2, Zeb, Snail, Slug) were significantly changed in response to alterations in HNF1α expression. On the other hand, overexpression of HNF1α did not induce any significant change in the aggressiveness of pancreatic cancer cells. Our results demonstrate that reduced expression of HNF1α leads to inhibition of pancreatic cancer growth and progression, which indicates that it could be a potential oncogene and target for PDAC.

Down-regulation of lncRNA PCGEM1 inhibits cervical carcinoma by modulating the miR-642a-5p/LGMN axis

LncRNA PCGEM1 (PCGEM1) has been reported to exert essential effects on the development and progress of various tumors, while the detailed effects and possible mechanisms of PCGEM1 in cervical carcinoma remain unknown. In the present study, PCGEM1 was over-expressed in cervical carcinoma cells as evidenced by real-time quantitative polymerase chain reaction (RT-qPCR) assay. Knockdown of PCGEM1 significantly repressed proliferation, migration, and invasion, while induced G1 arrest in cervical carcinoma cells. In addition, PCGEM1 was predicted to target miR-642a-5p by bioinformatics software, which was further confirmed by luciferase reporter assay. Besides, RT-qPCR assay indicated that miR-642a-5p expression was decreased in cervical carcinoma cells and knockdown of PCGEM1 could accelerate miR-642a-5p expression. Moreover, inhibition of miR-642a-5p partly abolished the functions of PCGEM1 knockdown on proliferation, cell cycle, migration and invasion of cervical carcinoma cells. Furthermore, miR-642a-5p could bind to the 3'-UTR of LGMN, which was over-expressed in the cervical carcinoma cells. Suppression of LGMN partly restored the functions of miR-642a-5p inhibitor on proliferation, cell cycle distribution, migration and invasion in the cervical carcinoma cells treated with the PCGEM1 shRNA. Taken together, our data indicated that knockdown of PCGEM1 inhibited proliferation, migration and invasion in cervical carcinoma by modulating the miR-642a-5p/ LGMN axis.

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.

Emerging Roles of Long Non-Coding RNAs in Renal Fibrosis

Renal fibrosis is an unavoidable consequence that occurs in nearly all of the nephropathies. It is characterized by a superabundant deposition and accumulation of extracellular matrix (ECM). All compartments in the kidney can be affected, including interstitium, glomeruli, vasculature, and other connective tissue, during the pathogenesis of renal fibrosis. The development of this process eventually causes destruction of renal parenchyma and end-stage renal failure, which is a devastating disease that requires renal replacement therapies. Recently, long non-coding RNAs (lncRNAs) have been emerging as key regulators governing gene expression and affecting various biological processes. These versatile roles include transcriptional regulation, organization of nuclear domains, and the regulation of RNA molecules or proteins. Current evidence proposes the involvement of lncRNAs in the pathologic process of kidney fibrosis. In this review, the biological relevance of lncRNAs in renal fibrosis will be clarified as important novel regulators and potential therapeutic targets. The biology, and subsequently the current understanding, of lncRNAs in renal fibrosis are demonstrated—highlighting the involvement of lncRNAs in kidney cell function, phenotype transition, and vascular damage and rarefaction. Finally, we discuss challenges and future prospects of lncRNAs in diagnostic markers and potential therapeutic targets, hoping to further inspire the management of renal fibrosis.

RNA helicase p68 inhibits the transcription and post-transcription of Pkd1 in ADPKD

Background: Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations of the PKD1 and PKD2 genes. Dysregulation of the expression of PKD genes, the abnormal activation of PKD associated signaling pathways, and the expression and maturation of miRNAs regulates cyst progression. However, the upstream factors regulating these abnormal processes in ADPKD remain elusive.

Methods: To investigate the roles of an RNA helicase, p68, in ADPKD, we performed Western blot and qRT-PCR analysis, immunostaining and ChIP assay in cystic renal epithelium cells and tissues.

Results: We found that p68 was upregulated in cystic renal epithelial cells and tissues. p68 represses Pkd1 gene expression via transcriptional and posttranscriptional mechanisms in renal epithelial cells, in that 1) p68 binds to the promoter of the Pkd1 gene together with p53 to repress transcription; and 2) p68 promotes the expression and maturation of miR-17, miR-200c and miR-182 and via these miRNAs, post-transcriptionally regulates the expression of Pkd1 mRNA. Drosha is involved in this process by forming a complex with p68. p68 also regulates the phosphorylation and activation of PKD proliferation associated signaling and the expression of fibrotic markers in Pkd1 mutant renal epithelial cells. Silence of p68 delays cyst formation in collecting duct cell mediated 3D cultures. In addition, the expression of p68 is induced by H₂O₂-dependent oxidative stress and DNA damage which causes downregulation of Pkd1 transcription in cystic renal epithelial cells and tissues.

Conclusions: p68 plays a critical role in negatively regulating the expression of the PKD1 gene along with positively regulating the expression and maturation of miRNAs and activation of PKD associated signaling pathways to cause renal cyst progression and fibrosis in ADPKD.

Tranilast induces MiR-200c expression through blockade of RelA/p65 activity in leiomyoma smooth muscle cells

OBJECTIVE

To determine the mechanism by which tranilast induces miR-200c expression in leiomyoma smooth muscle cells (LSMCs).

DESIGN

Experimental study.

SETTING

Academic research laboratory.

PATIENT(S)

Women undergoing hysterectomy for leiomyoma.

INTERVENTION(S)

Blockade of RelA/p65.

MAIN OUTCOME MEASURE(S)

Effects of tranilast and blockade of RelA/p65 on miR-200c expression.

RESULT(S)

Tranilast, an inflammation inhibitor, dose-dependently induced miR-200c in LSMCs and myometrium smooth muscle cells (MSMCs), with a more profound effect in LSMCs than in MSMCs. The treatment of LSMCs with Bay 117082, an inhibitor of IκB phosphorylation, further enhanced miR-200c induction by tranilast. The knockdown of RelA/p65 by small interfering RNA also induced miR-200c expression in LSMCs. Although tranilast had no effect on total RelA/p65 protein levels in LSMCs, it significantly induced RelA/p65 phosphorylation at S536 while reducing its activity as well as its nuclear translocation. ChIP assay indicated that tranilast reduces the binding ability of RelA/p65 to miR-200c promoter, resulting in miR-200c induction. Tranilast also inhibited interleukin-8 (IL8) expression in LSMCs. The induction of miR-200c by tranilast partially mediates the inhibitory effect of tranilast on the expression of IL8 and cyclin-dependent kinase 2 in LSMCs.

CONCLUSION(S)

Induction of miR-200c by tranilast in LSMCs is mediated through a transcriptional mechanism involving inhibition of the nuclear factor κB signaling pathway. These results highlight the significance of inflammation in the pathogenesis of leiomyoma and the potential utility of antiinflammatory drugs for treatment of leiomyomas.

Role of transcription factor hepatocyte nuclear factor-1β in polycystic kidney disease

Hepatocyte nuclear factor-1β (HNF-1β) is a DNA-binding transcription factor that is essential for normal kidney development. Mutations of HNF1B in humans produce cystic kidney diseases, including renal cysts and diabetes, multicystic dysplastic kidneys, glomerulocystic kidney disease, and autosomal dominant tubulointerstitial kidney disease. Expression of HNF1B is reduced in cystic kidneys from humans with ADPKD, and HNF1B has been identified as a modifier gene in PKD. Genome-wide analysis of chromatin binding has revealed that HNF-1β directly regulates the expression of known PKD genes, such as PKHD1 and PKD2, as well as genes involved in PKD pathogenesis, including cAMP-dependent signaling, renal fibrosis, and Wnt signaling. In addition, a role of HNF-1β in regulating the expression of noncoding RNAs (microRNAs and long noncoding RNAs) has been identified. These findings indicate that HNF-1β regulates a transcriptional and post-transcriptional network that plays a central role in renal cystogenesis.

DNMT1 recruited by EZH2-mediated silencing of miR-484 contributes to the malignancy of cervical cancer cells through MMP14 and HNF1A

BACKGROUND

Emerging evidence indicates that dysregulation of microRNAs (miRNAs) contributes to cervical cancer (CC) tumorigenesis and development. Previous work showed that miR-484 which regulated the EMT process was obviously downregulated in CC. However, little is known about the precise mechanism.

RESULTS

We found that the deficiency of EZH2-recruited DNA methyltransferases DNMT1 reduced the CpG methylation of miR-484 promoter and then increased the miR-484 expression. Furthermore, the cell membrane-bound matrix metalloproteinase (MMP14) and the hepatocyte nuclear factor 1A (HNF1A) were found to be downregulated by miR-484. miR-484 repressed the expression of MMP14 and HNF1A inhibiting CC growth and metastasis in vitro and in vivo. Upregulation of MMP14 and HNF1A promotes the CC cell adhesion and EMT, all of which contribute to cell motility and metastasis. Moreover, miR-484 negatively regulates the WNT/MAPK and TNF signaling pathway by downregulating HNF1A and MMP14 respectively. Thus, miR-484, who is downregulated by DNMT1-mediated hypermethylation in its promoter, functions as a tumor suppressor by inhibiting MMP14 and HNF1A expression in CC.

CONCLUSION

Our finding characterizes miR-484 as a key suppressive regulator in CC metastasis and reveals a DNMT1-mediated epigenetic mechanism for miR-484 silencing, expanding our understanding of the molecular mechanism underlying CC progression and metastasis.

Hepatocyte nuclear factor-1β regulates Wnt signaling through genome-wide competition with β-catenin/lymphoid enhancer binding factor

Hepatocyte nuclear factor-1β (HNF-1β) is a tissue-specific transcription factor that is essential for normal kidney development and renal tubular function. Mutations of HNF-1β produce cystic kidney disease, a phenotype associated with deregulation of canonical (β-catenin-dependent) Wnt signaling. Here, we show that ablation of HNF-1β in mIMCD3 renal epithelial cells produces hyperresponsiveness to Wnt ligands and increases expression of Wnt target genes, including Axin2, Ccdc80, and Rnf43 Levels of β-catenin and expression of Wnt target genes are also increased in HNF-1β mutant mouse kidneys. Genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) in wild-type and mutant cells showed that ablation of HNF-1β increases by 6-fold the number of sites on chromatin that are occupied by β-catenin. Remarkably, 50% of the sites that are occupied by β-catenin in HNF-1β mutant cells colocalize with HNF-1β-occupied sites in wild-type cells, indicating widespread reciprocal binding. We found that the Wnt target genes Ccdc80 and Rnf43 contain a composite DNA element comprising a β-catenin/lymphoid enhancer binding factor (LEF) site overlapping with an HNF-1β half-site. HNF-1β and β-catenin/LEF compete for binding to this element, and thereby HNF-1β inhibits β-catenin-dependent transcription. Collectively, these studies reveal a mechanism whereby a transcription factor constrains canonical Wnt signaling through direct inhibition of β-catenin/LEF chromatin binding.

Emerging role of miRNAs in renal fibrosis

As one type of the most common endogenous short noncoding RNAs (ncRNAs), microRNAs (miRNAs) act as posttranscriptional regulators of gene expression and have great potential biological functions in the physiological and pathological processes of various diseases. The role of miRNAs in renal fibrosis has also attracted great attention in the previous 20 years, and new therapeutic strategies targeting miRNAs appear to be promising. Some researchers have previously reviewed the roles of miRNA in renal fibrosis disease, but numerous studies have emerged over the recent 5 years. It is necessary to update and summarize research progress in miRNAs in renal fibrosis. Thus, in this review, we summarize progress in miRNA-mediated renal fibrosis over the last 5 years and evaluate the biological functions of some miRNAs in different stages of renal fibrosis. Furthermore, we also expound the recent clinical applications of these miRNAs to provide new insights into the treatment of renal fibrosis disease.

New insights into the role of HNF-1β in kidney (patho)physiology

Hepatocyte nuclear factor-1β (HNF-1β) is an essential transcription factor that regulates the development and function of epithelia in the kidney, liver, pancreas, and genitourinary tract. Humans who carry HNF1B mutations develop heterogeneous renal abnormalities, including multicystic dysplastic kidneys, glomerulocystic kidney disease, renal agenesis, renal hypoplasia, and renal interstitial fibrosis. In the embryonic kidney, HNF-1β is required for ureteric bud branching, initiation of nephrogenesis, and nephron segmentation. Ablation of mouse Hnf1b in nephron progenitors causes defective tubulogenesis, whereas later inactivation in elongating tubules leads to cyst formation due to downregulation of cystic disease genes, including Umod, Pkhd1, and Pkd2. In the adult kidney, HNF-1β controls the expression of genes required for intrarenal metabolism and solute transport by tubular epithelial cells. Tubular abnormalities observed in HNF-1β nephropathy include hyperuricemia with or without gout, hypokalemia, hypomagnesemia, and polyuria. Recent studies have identified novel post-transcriptional and post-translational regulatory mechanisms that control HNF-1β expression and activity, including the miRNA cluster miR17 ∼ 92 and the interacting proteins PCBD1 and zyxin. Further understanding of the molecular mechanisms upstream and downstream of HNF-1β may lead to the development of new therapeutic approaches in cystic kidney disease and other HNF1B-related renal diseases.

miR-194 regulates the proliferation and migration via targeting Hnf1β in mouse metanephric mesenchyme cells

Hepatocyte nuclear factor-1β (Hnf1β) is associated with early embryogenesis failure, renal cysts, and/or diabetes. However, factors regulating Hnf1β expression in metanephric mesenchyme cells remain poorly understood. Here, we analyzed the modulation relationship of Hnf1β and miR-194 in mouse metanephric mesenchyme (MM) cells. Bioinformatics analysis, luciferase assay and semi-quantitative real-time (qPCR), western blotting, 5-ethynyl-2'-deoxyuridine cell proliferation assay, wound healing assay, and flow cytometry were employed to detect the function of miR-194 by targeting on Hnf1β in mouse MM cells. Bioinformatic prediction revealed one conserved binding site (CAGTATT) of miR-194 on Hnf1β 3'-UTR and luciferase reporter assay suggested that this is an effective target site of miR-194, and mutating CAGTATT with CGTACTT had no effects on luciferase activity compared with control. Overexpression of miR-194 decreased Hnf1β mRNA and protein level in mouse MM cells. In addition, miR-194-decreased cell proliferation and miR-194-promoted cell apoptosis and migration were reversed by overexpression of Hnf1β coding region. In addition, Hnf1β-upregulated genes were decreased in miR-194 overexpression cells and rescued in miR-194 and Hnf1β CDS region co-overexpression cells. Our findings explored one new regulator of Hnf1β and revealed the function of their regulation in cell proliferation, migration, and apoptosis in mouse metanephric mesenchyme cells. For strict regulation of Hnf1β in kidney development, these findings provide theoretical guidance for kidney development study and kidney disease therapy.

Systematic evaluation of C. elegans lincRNAs with CRISPR knockout mutants

Background

Long intergenic RNAs (lincRNAs) play critical roles in eukaryotic cells, but systematic analyses of the lincRNAs of an animal for phenotypes are lacking. We generate CRISPR knockout strains for Caenorhabditis elegans lincRNAs and evaluate their phenotypes.

Results

C. elegans lincRNAs demonstrate global features such as shorter length and fewer exons than mRNAs. For the systematic evaluation of C. elegans lincRNAs, we produce CRISPR knockout strains for 155 of the total 170 C. elegans lincRNAs. Mutants of 23 lincRNAs show phenotypes in 6 analyzed traits. We investigate these lincRNAs by phenotype for their gene expression patterns and potential functional mechanisms. Some C. elegans lincRNAs play cis roles to modulate the expression of their neighboring genes, and several lincRNAs play trans roles as ceRNAs against microRNAs. We also examine the regulation of lincRNA expression by transcription factors, and we dissect the pathway by which two transcription factors, UNC-30 and UNC-55, together control the expression of linc-73. Furthermore, linc-73 possesses a cis function to modulate the expression of its neighboring kinesin gene unc-104 and thus plays roles in C. elegans locomotion.

Conclusions

By using CRISPR/cas9 technology, we generate knockout strains of 155 C. elegans lincRNAs as valuable resources for studies in noncoding RNAs, and we provide biological insights for 23 lincRNAs with the phenotypes identified in this study.

Electronic supplementary material

The online version of this article (10.1186/s13059-018-1619-6) contains supplementary material, which is available to authorized users.

Unique interstitial miRNA signature drives fibrosis in a murine model of autosomal dominant polycystic kidney disease

AIM

To delineate changes in miRNA expression localized to the peri-cystic local microenvironment (PLM) in an orthologous mouse model of autosomal dominant polycystic kidney disease (ADPKD) (mcwPkd1^(nl/nl)).

METHODS

We profiled miRNA expression in the whole kidney and laser captured microdissection (LCM) samples from PLM in mcwPkd1^(nl/nl) kidneys with Qiagen miScript 384 HC miRNA PCR arrays. The three times points used are: (1) post-natal (PN) day 21, before the development of trichrome-positive areas; (2) PN28, the earliest sign of trichrome staining; and (3) PN42 following the development of progressive fibrosis. PN21 served as appropriate controls and as the reference time point for comparison of miRNA expression profiles.

RESULTS

LCM samples revealed three temporally upregulated miRNAs [2 to 2.75-fold at PN28 and 2.5 to 4-fold (P ≤ 0.05) at PN42] and four temporally downregulated miRNAs [2 to 2.75 fold at PN28 and 2.75 to 5-fold (P ≤ 0.05) at PN42]. Expression of twenty-six miRNAs showed no change until PN42 [six decreased (2.25 to 3.5-fold) (P ≤ 0.05) and 20 increased (2 to 4-fold) (P ≤ 0.05)]. Many critical miRNA changes seen in the LCM samples from PLM were not seen in the contralateral whole kidney.

CONCLUSION

Precise sampling with LCM identifies miRNA changes that occur with the initiation and progression of renal interstitial fibrosis (RIF). Identification of the target proteins regulated by these miRNAs will provide new insight into the process of fibrosis and identify unique therapeutic targets to prevent or slow the development and progression of RIF in ADPKD.

Innovation for hepatotoxicity in vitro research models: A review

Many categories of drugs can induce hepatotoxicity, so improving the prediction of toxic drugs is important. In vitro models using human hepatocytes are more accurate than in vivo animal models. Good in vitro models require an abundance of metabolic enzyme activities and normal cellular polarity. However, none of the in vitro models can completely simulate hepatocytes in the human body. There are two ways to overcome this limitation: enhancing the metabolic function of hepatocytes and changing the cultural environment. In this review, we summarize the current state of research, including the main characteristics of in vitro models and their limitations, as well as improved technology and developmental prospects. We hope that this review provides some new ideas for hepatotoxicity research.

Mechanism of Fibrosis in HNF1B-Related Autosomal Dominant Tubulointerstitial Kidney Disease

BACKGROUND

Mutation of HNF1B, the gene encoding transcription factor HNF-1β, is one cause of autosomal dominant tubulointerstitial kidney disease, a syndrome characterized by tubular cysts, renal fibrosis, and progressive decline in renal function. HNF-1β has also been implicated in epithelial-mesenchymal transition (EMT) pathways, and sustained EMT is associated with tissue fibrosis. The mechanism whereby mutated HNF1B leads to tubulointerstitial fibrosis is not known.

METHODS

To explore the mechanism of fibrosis, we created HNF-1β-deficient mIMCD3 renal epithelial cells, used RNA-sequencing analysis to reveal differentially expressed genes in wild-type and HNF-1β-deficient mIMCD3 cells, and performed cell lineage analysis in HNF-1β mutant mice.

RESULTS

The HNF-1β-deficient cells exhibited properties characteristic of mesenchymal cells such as fibroblasts, including spindle-shaped morphology, loss of contact inhibition, and increased cell migration. These cells also showed upregulation of fibrosis and EMT pathways, including upregulation of Twist2, Snail1, Snail2, and Zeb2, which are key EMT transcription factors. Mechanistically, HNF-1β directly represses Twist2, and ablation of Twist2 partially rescued the fibroblastic phenotype of HNF-1β mutant cells. Kidneys from HNF-1β mutant mice showed increased expression of Twist2 and its downstream target Snai2. Cell lineage analysis indicated that HNF-1β mutant epithelial cells do not transdifferentiate into kidney myofibroblasts. Rather, HNF-1β mutant epithelial cells secrete high levels of TGF-β ligands that activate downstream Smad transcription factors in renal interstitial cells.

CONCLUSIONS

Ablation of HNF-1β in renal epithelial cells leads to the activation of a Twist2-dependent transcriptional network that induces EMT and aberrant TGF-β signaling, resulting in renal fibrosis through a cell-nonautonomous mechanism.

Cumulative evidence for relationships between multiple variants of HNF1B and the risk of prostate and endometrial cancers

Background

To provide a synopsis of the current understanding of the association between variants of HNF1B and cancer susceptibility, we conducted a comprehensive research synopsis and meta-analysis to evaluate associations between HNF1B variants and prostate and endometrial cancers.

Results

Eighteen studies totaling 34,937 patients and 55,969 controls were eligible for this meta-analysis. Four variants showed a significant association with the risk of individual cancer. Strong significant associations were found between rs4430796 A and the risk of both prostate cancer (OR = 1.247, p = 2.21 × 10^− 77) and endometrial cancer (OR = 1.217, p = 8.98 × 10^− 16); the AA, AG genotypes also showed strong significant associations with the risk of prostate cancer (OR1 = 1.517, p = 4.46 × 10^− 22; OR2 = 1.180, p = 0.002). There was a strong significant association between rs7501939 G and the risk of prostate cancer (OR = 1.201, p = 9.31 × 10^− 31). Strong significant association was found between rs11649743 G (OR = 1.138, p = 1.08 × 10^− 12), rs3760511 C (OR = 1.214, p = 1.57 × 10^− 19) and the prostate cancer risk;the GG, AG genotypes of rs11649743 also showed strong significant associations with the risk of prostate cancer (OR1 = 1.496, p = 3.32 × 10^− 6; OR2 = 1.276, p = 7.82 × 10^− 6). All the cumulative epidemiological evidence of associations was graded as strong.

Conclusions

Our study summarizes the evidence and helps to reveal that common variants of HNF1B are associated with risk of prostate and endometrial cancer.

lncRNAs are novel biomarkers for differentiating between cisplatin-resistant and cisplatin-sensitive ovarian cancer

Cisplatin-resistant ovarian cancer occurs in patients with ovarian cancer treated with cisplatin-based chemotherapy, which results in tumor progression during treatment, or recurrence of the tumor within 6 months of the treatment. It is vital that a novel biomarker for diagnosis, or an efficient therapeutic target of cisplatin-resistant ovarian is identified. Long non-coding (lnc)RNAs were determined to serve critical functions in a variety of distinct types of cancer, including ovarian cancer; however, there is limited knowledge regarding the differential expression levels of lncRNAs in cisplatin-resistant and cisplatin-sensitive ovarian cancer. Therefore, in the present study, the expression levels were determined for these cancer types. The lncRNA expression profile in cisplatin-resistant ovarian cancer was analyzed and compared with the results for cisplatin-sensitive ovarian cancer; gene ontology and pathway analysis demonstrated that the dysregulated lncRNAs participated in important biological processes. Subsequently, it was identified that these dysregulated lncRNAs were present in other ovarian cancer tissues and in SKOV3 ovarian cancer cells, as well as its cisplatin-resistant clone, SKOV3/CDDP. In addition, it was revealed that 8 lncRNAs (Enst0000435726, Enst00000585612, Enst00000566734, Enst00000453783, NR_023915, RP11_697E22.2, uc010jub.1 and tcons_00008505) were associated with cisplatin-resistant ovarian cancer. The present study may assist in improving understanding of the initiation and developmental mechanisms underlying cisplatin-resistant ovarian cancer, which could aid future studies in discovering potential biomarkers for diagnosis or therapeutic targets that may be used in clinical treatment.

Network-directed cis-mediator analysis of normal prostate tissue expression profiles reveals downstream regulatory associations of prostate cancer susceptibility loci

Large-scale genome-wide association studies have identified multiple single-nucleotide polymorphisms associated with risk of prostate cancer. Many of these genetic variants are presumed to be regulatory in nature; however, follow-up expression quantitative trait loci (eQTL) association studies have to-date been restricted largely to cis-acting associations due to study limitations. While trans-eQTL scans suffer from high testing dimensionality, recent evidence indicates most trans-eQTL associations are mediated by cis-regulated genes, such as transcription factors. Leveraging a data-driven gene co-expression network, we conducted a comprehensive cis-mediator analysis using RNA-Seq data from 471 normal prostate tissue samples to identify downstream regulatory associations of previously identified prostate cancer risk variants. We discovered multiple trans-eQTL associations that were significantly mediated by cis-regulated transcripts, four of which involved risk locus 17q12, proximal transcription factor HNF1B, and target trans-genes with known HNF response elements (MIA2, SRC, SEMA6A, KIF12). We additionally identified evidence of cis-acting down-regulation of MSMB via rs10993994 corresponding to reduced co-expression of NDRG1. The majority of these cis-mediator relationships demonstrated trans-eQTL replicability in 87 prostate tissue samples from the Gene-Tissue Expression Project. These findings provide further biological context to known risk loci and outline new hypotheses for investigation into the etiology of prostate cancer.

Suppression of microRNA Activity in Kidney Collecting Ducts Induces Partial Loss of Epithelial Phenotype and Renal Fibrosis

microRNAs (miRNAs) are sequence-specific inhibitors of post-transcriptional gene expression. The physiologic function of these noncoding RNAs in postnatal renal tubules still remains unclear. Surprisingly, they appear to be dispensable for mammalian proximal tubule (PT) function. Here, we examined the effects of miRNA suppression in collecting ducts (CDs). To conclusively evaluate the role of miRNAs, we generated three mouse models with CD-specific inactivation of key miRNA pathway genes Dicer, Dgcr8, and the entire Argonaute gene family (Ago1, 2, 3, and 4). Characterization of these three mouse models revealed that inhibition of miRNAs in CDs spontaneously evokes a renal tubule injury-like response, which culminates in progressive tubulointerstitial fibrosis (TIF) and renal failure. Global miRNA profiling of microdissected renal tubules showed that miRNAs exhibit segmental distribution along the nephron and CDs. In particular, the expression of miR-200c is nearly 70-fold higher in CDs compared with PTs. Accordingly, miR-200s are downregulated in Dicer-KO CDs, its direct target genes Zeb1, Zeb2, and Snail2 are upregulated, and miRNA-depleted CDs undergo partial epithelial-to-mesenchymal transition (EMT). Thus, miRNAs are essential for CD homeostasis. Downregulation of CD-enriched miRNAs and the subsequent induction of partial EMT may be a new mechanism for TIF progression.

Long non-coding RNAs-towards precision medicine in diabetic kidney disease?

Diabetic kidney disease (DKD) is escalating and is the major cause of end stage kidney failure. There is increasing evidence to support the role of epigenetic factors and metabolic memory in linking the environmental and genetic causes of this disease. Although our understanding of this disease has improved, there has been no significant efficacious therapeutic translation in the last decade. Current sequencing technology has allowed interrogation of the human transcriptome. It is evident that although approximately 80% of the genome is transcribed, only 1-2% is read and coded into protein. The remaining non-coding RNA, historically assumed to be 'junk', is now known to have key roles in regulating gene function and orchestrate how and when coding genes are expressed. This largest subset of non-coding RNAs called long non-coding RNAs (LNCRNAs) drives epigenetic changes and has functional relevance best characterized in cancers and cardiovascular disease. This understanding, coupled with the availability and affordability of RNA sequencing, has shifted our therapeutic strategies towards genomic therapy in DKD. The role of LNCRNAs with respect to DKD is only just emerging. In this review we summarize the role of LNCRNAs in DKD and the existing antisense oligonucleotide therapy that may provide precise and targeted medicine to treat DKD in this postgenomic era.

The Functions of MicroRNA-200 Family in Ovarian Cancer: Beyond Epithelial-Mesenchymal Transition

The majority of studies on microRNA-200 family members (miR-200s) in human cancers are based on the premise that miR-200s maintain epithelial cell integrity by suppressing epithelial-mesenchymal transition (EMT) through direct inhibition of mesenchymal transcription factors zinc finger E-box-binding homeobox 1/2 (ZEB1/ZEB2) and transforming growth factor-β (TGF-β), a potent inducer of EMT. Hence, downregulation of miR-200 in cancer cells promotes EMT and cancer metastasis. Yet, miR-200s are highly expressed in ovarian cancer, and ovarian cancer metastasizes primarily by dissemination within the pelvic cavity. In this review, we will refocus the epithelial property of ovarian cancer cells and the role of miR-200s in safeguarding this property, as well as the diverse roles of miR-200s in inclusion cyst formation, cancer cell growth, collective movement, angiogenesis, exosome-mediated cell communication, and chemoresponse. Taken together, miR-200s play a significant role in the initiation, progression and metastasis of ovarian cancer and may serve as diagnostic biomarkers and a target in therapeutic development.

The Functions of MicroRNA-200 Family in Ovarian Cancer: Beyond Epithelial-Mesenchymal Transition

The majority of studies on microRNA-200 family members (miR-200s) in human cancers are based on the premise that miR-200s maintain epithelial cell integrity by suppressing epithelial-mesenchymal transition (EMT) through direct inhibition of mesenchymal transcription factors zinc finger E-box-binding homeobox 1/2 (ZEB1/ZEB2) and transforming growth factor-β (TGF-β), a potent inducer of EMT. Hence, downregulation of miR-200 in cancer cells promotes EMT and cancer metastasis. Yet, miR-200s are highly expressed in ovarian cancer, and ovarian cancer metastasizes primarily by dissemination within the pelvic cavity. In this review, we will refocus the epithelial property of ovarian cancer cells and the role of miR-200s in safeguarding this property, as well as the diverse roles of miR-200s in inclusion cyst formation, cancer cell growth, collective movement, angiogenesis, exosome-mediated cell communication, and chemoresponse. Taken together, miR-200s play a significant role in the initiation, progression and metastasis of ovarian cancer and may serve as diagnostic biomarkers and a target in therapeutic development.

The Functions of MicroRNA-200 Family in Ovarian Cancer: Beyond Epithelial-Mesenchymal Transition

The majority of studies on microRNA-200 family members (miR-200s) in human cancers are based on the premise that miR-200s maintain epithelial cell integrity by suppressing epithelial-mesenchymal transition (EMT) through direct inhibition of mesenchymal transcription factors zinc finger E-box-binding homeobox 1/2 (ZEB1/ZEB2) and transforming growth factor-β (TGF-β), a potent inducer of EMT. Hence, downregulation of miR-200 in cancer cells promotes EMT and cancer metastasis. Yet, miR-200s are highly expressed in ovarian cancer, and ovarian cancer metastasizes primarily by dissemination within the pelvic cavity. In this review, we will refocus the epithelial property of ovarian cancer cells and the role of miR-200s in safeguarding this property, as well as the diverse roles of miR-200s in inclusion cyst formation, cancer cell growth, collective movement, angiogenesis, exosome-mediated cell communication, and chemoresponse. Taken together, miR-200s play a significant role in the initiation, progression and metastasis of ovarian cancer and may serve as diagnostic biomarkers and a target in therapeutic development.

Hepatocyte Nuclear Factor-1β Regulates Urinary Concentration and Response to Hypertonicity

The transcription factor hepatocyte nuclear factor-1β (HNF-1β) is essential for normal kidney development and function. Inactivation of HNF-1β in mouse kidney tubules leads to early-onset cyst formation and postnatal lethality. Here, we used Pkhd1/Cre mice to delete HNF-1β specifically in renal collecting ducts (CDs). CD-specific HNF-1β mutant mice survived long term and developed slowly progressive cystic kidney disease, renal fibrosis, and hydronephrosis. Compared with wild-type littermates, HNF-1β mutant mice exhibited polyuria and polydipsia. Before the development of significant renal structural abnormalities, mutant mice exhibited low urine osmolality at baseline and after water restriction and administration of desmopressin. However, mutant and wild-type mice had similar plasma vasopressin and solute excretion levels. HNF-1β mutant kidneys showed increased expression of aquaporin-2 mRNA but mislocalized expression of aquaporin-2 protein in the cytoplasm of CD cells. Mutant kidneys also had decreased expression of the UT-A urea transporter and collectrin, which is involved in apical membrane vesicle trafficking. Treatment of HNF-1β mutant mIMCD3 cells with hypertonic NaCl inhibited the induction of osmoregulated genes, including Nr1h4, which encodes the transcription factor FXR that is required for maximal urinary concentration. Chromatin immunoprecipitation and sequencing experiments revealed HNF-1β binding to the Nr1h4 promoter in wild-type kidneys, and immunoblot analysis revealed downregulated expression of FXR in HNF-1β mutant kidneys. These findings reveal a novel role of HNF-1β in osmoregulation and identify multiple mechanisms, whereby mutations of HNF-1β produce defects in urinary concentration.

Long noncoding RNAs in the pathogenesis of diabetic kidney disease: implications for novel therapeutic strategies

Diabetic kidney disease is a progressive disorder that develops secondary to diabetes. Current strategies for the clinical management of the disease can delay its onset and prevent progression, yet a significant proportion of patients still develop renal failure. The need for more advanced pharmaceuticals is therefore critical for improved treatment strategies. Recent studies support a role for long noncoding RNAs (lncRNAs) in the pathogenesis of human disease. Here we review recent experimental results linking lncRNAs with diabetic kidney disease. A better understanding of the regulatory role that lncRNAs play in the development of diabetic kidney disease may lead to identification of novel targets for therapeutic intervention.

lncRNA Functional Networks in Oligodendrocytes Reveal Stage-Specific Myelination Control by an lncOL1/Suz12 Complex in the CNS

Long noncoding RNAs (lncRNAs) are emerging as important regulators of cellular functions, but their roles in oligodendrocyte myelination remain undefined. Through de novo transcriptome reconstruction, we establish dynamic expression profiles of lncRNAs at different stages of oligodendrocyte development and uncover a cohort of stage-specific oligodendrocyte-restricted lncRNAs, including a conserved chromatin-associated lncOL1. Co-expression network analyses further define the association of distinct oligodendrocyte-expressing lncRNA clusters with protein-coding genes and predict lncRNA functions in oligodendrocyte myelination. Overexpression of lncOL1 promotes precocious oligodendrocyte differentiation in the developing brain, whereas genetic inactivation of lncOL1 causes defects in CNS myelination and remyelination following injury. Functional analyses illustrate that lncOL1 interacts with Suz12, a component of polycomb repressive complex 2, to promote oligodendrocyte maturation, in part, through Suz12-mediated repression of a differentiation inhibitory network that maintains the precursor state. Together, our findings reveal a key lncRNA epigenetic circuitry through interaction with chromatin-modifying complexes in control of CNS myelination and myelin repair.

Inhibition of the processing of miR-25 by HIPK2-Phosphorylated-MeCP2 induces NOX4 in early diabetic nephropathy

Phosphorylated methyl-CpG binding protein2 (p-MeCP2) suppresses the processing of several microRNAs (miRNAs). Homeo-domain interacting protein kinase2 (HIPK2) phosphorylates MeCP2, a known transcriptional repressor. However, it is not known if MeCP2 and HIPK2 are involved in processing of miRNAs implicated in diabetic nephropathy. p-MeCP2 and HIPK2 levels were significantly increased, but Seven in Absentia Homolog1 (SIAH1), which mediates proteasomal degradation of HIPK2, was decreased in the glomeruli of streptozotocin injected diabetic mice. Among several miRNAs, miR-25 and its precursor were significantly decreased in diabetic mice, whereas primary miR-25 levels were significantly increased. NADPH oxidase4 (NOX4), a target of miR-25, was significantly increased in diabetic mice. Protein levels of p-MeCP2, HIPK2, and NOX4 were increased in high glucose (HG)- or TGF-β-treated mouse glomerular mesangial cells (MMCs). miR-25 (primary, precursor, and mature) and mRNA levels of genes indicated in the in vivo study showed similar trends of regulation in MMCs treated with HG or TGF-β. The HG- or TGF-β-induced upregulation of p-MeCP2, NOX4 and primary miR-25, but downregulation of precursor and mature miR-25, were attenuated by Hipk2 siRNA. These results demonstrate a novel role for the SIAH1/HIPK2/MeCP2 axis in suppressing miR-25 processing and thereby upregulating NOX4 in early diabetic nephropathy.

An endoplasmic reticulum stress-regulated lncRNA hosting a microRNA megacluster induces early features of diabetic nephropathy

It is important to find better treatments for diabetic nephropathy (DN), a debilitating renal complication. Targeting early features of DN, including renal extracellular matrix accumulation (ECM) and glomerular hypertrophy, can prevent disease progression. Here we show that a megacluster of nearly 40 microRNAs and their host long non-coding RNA transcript (lnc-MGC) are coordinately increased in the glomeruli of mouse models of DN, and mesangial cells treated with transforming growth factor-β1 (TGF- β1) or high glucose. Lnc-MGC is regulated by an endoplasmic reticulum (ER) stress-related transcription factor, CHOP. Cluster microRNAs and lnc-MGC are decreased in diabetic Chop^-/- mice that showed protection from DN. Target genes of megacluster microRNAs have functions related to protein synthesis and ER stress. A chemically modified oligonucleotide targeting lnc-MGC inhibits cluster microRNAs, glomerular ECM and hypertrophy in diabetic mice. Relevance to human DN is also demonstrated. These results demonstrate the translational implications of targeting lnc-MGC for controlling DN progression.

Loss of Zeb2 in mesenchyme-derived nephrons causes primary glomerulocystic disease

Primary glomerulocystic kidney disease is a special form of renal cystic disorder characterized by Bowman's space dilatation in the absence of tubular cysts. ZEB2 is a SMAD-interacting transcription factor involved in Mowat-Wilson syndrome, a congenital disorder with an increased risk for kidney anomalies. Here we show that deletion of Zeb2 in mesenchyme-derived nephrons with either Pax2-cre or Six2-cre causes primary glomerulocystic kidney disease without tubular cysts in mice. Glomerulotubular junction analysis revealed many atubular glomeruli in the kidneys of Zeb2 knockout mice, which explains the presence of glomerular cysts in the absence of tubular dilatation. Gene expression analysis showed decreased expression of early proximal tubular markers in the kidneys of Zeb2 knockout mice preceding glomerular cyst formation, suggesting that defects in proximal tubule development during early nephrogenesis contribute to the formation of congenital atubular glomeruli. At the molecular level, Zeb2 deletion caused aberrant expression of Pkd1, Hnf1β, and Glis3, three genes causing glomerular cysts. Thus, Zeb2 regulates the morphogenesis of mesenchyme-derived nephrons and is required for proximal tubule development and glomerulotubular junction formation. Our findings also suggest that ZEB2 might be a novel disease gene in patients with primary glomerular cystic disease.

Differential regulation of serum microRNA expression by HNF1β and HNF1α transcription factors

AIMS/HYPOTHESIS

We aimed to identify microRNAs (miRNAs) under transcriptional control of the HNF1β transcription factor, and investigate whether its effect manifests in serum.

METHODS

The Polish cohort (N = 60) consisted of 11 patients with HNF1B-MODY, 17 with HNF1A-MODY, 13 with GCK-MODY, an HbA1c-matched type 1 diabetic group (n = 9) and ten healthy controls. Replication was performed in 61 clinically-matched British patients mirroring the groups in the Polish cohort. The Polish cohort underwent miRNA serum level profiling with quantitative real-time PCR (qPCR) arrays to identify differentially expressed miRNAs. Validation was performed using qPCR. To determine whether serum content reflects alterations at a cellular level, we quantified miRNA levels in a human hepatocyte cell line (HepG2) with small interfering RNA knockdowns of HNF1α or HNF1β.

RESULTS

Significant differences (adjusted p < 0.05) were noted for 11 miRNAs. Five of them differed between HNF1A-MODY and HNF1B-MODY, and, amongst those, four (miR-24, miR-27b, miR-223 and miR-199a) showed HNF1B-MODY-specific expression levels in the replication group. In all four cases the miRNA expression level was lower in HNF1B-MODY than in all other tested groups. Areas under the receiver operating characteristic curves ranged from 0.79 to 0.86, with sensitivity and specificity reaching 91.7% (miR-24) and 82.1% (miR-199a), respectively. The cellular expression pattern of miRNA was consistent with serum levels, as all were significantly higher in HNF1α- than in HNF1β-deficient HepG2 cells.

CONCLUSIONS/INTERPRETATION

We have shown that expression of specific miRNAs depends on HNF1β function. The impact of HNF1β deficiency was evidenced at serum level, making HNF1β-dependent miRNAs potentially applicable in the diagnosis of HNF1B-MODY.

A novel long non-coding RNA CYP4B1-PS1-001 regulates proliferation and fibrosis in diabetic nephropathy

Diabetic nephropathy is an important microvascular complication of diabetes, and the incidence of end-stage renal disease caused by it are rising annually. Long non-coding RNAs (lncRNAs) are widely regarded to associate with the occurrence and development of various diseases; however, the relationship between lncRNAs and diabetic nephropathy remains largely unknown. This work studied the effect of lncRNAs on diabetic nephropathy pathogenesis. LncRNA microarrays were initially used to detect lncRNAs with altered expression in three cases of kidney tissue from db/db mice with diabetic nephropathy. LncRNAs with differential expression (>2-fold) could be considered candidates. Particularly, CYP4B1-PS1-001 was significantly downregulated in response to early diabetic nephropathy in vitro and in vivo, while overexpression of CYP4B1-PS1-001 inhibited proliferation and fibrosis of mesangial cells. Overall, our data indicate the potential role of CYP4B1-PS1-001 in the proliferation and fibrosis of mice mesangial cells as the prominent features during early stage of diabetic nephropathy, which extend the relationship between lncRNAs and diabetic nephropathy, and may provide a potential therapeutic target and molecular biomarker for the disease.