Renal epithelial miR-205 expression correlates with disease severity in a mouse model of congenital obstructive nephropathy

miR-217 through SIRT1 regulates the immunotoxicity of cadmium in Cyprinus carpio

MicroRNAs (miRNAs) play a critical role in regulating the response of animals exposed to heavy metal stress. As a globally dispersed heavy metal in aquatic ecosystems, cadmium (Cd) is highly toxic to many aquatic species. However, little is known about the miRNA response to Cd stress in fish. To investigate the regulatory effect of miRNAs in response to Cd, common carp (Cyprinus carpio) were exposed to Cd²⁺-containing water (0.005 mg/L, 0.05 mg/L, 0.5 mg/L) for 30 days. After exposure, Cd²⁺ contents were significantly higher in the kidneys of C. carpio compared to other tissues, when exposed to 0.5 mg/L Cd²⁺. Hematoxylin and eosin staining images revealed that elevated Cd induced inflammatory damage in the kidneys of C.carpio. Further, miRNA sequencing revealed nine differentially expressed miRNAs (miR-217, miR-205 and seven novel miRNAs) in the kidneys, between 0.5 mg/L Cd²⁺ exposure and control groups. Potential target mRNAs of miRNAs suggest that miR-217 is involved in immunotoxicity. miR-217 agomir was intraperitoneally administered to C. carpio and RT-PCR revealed that the expression of IL-8 and SIRT1 decreased, while TLR-4, TRAF6, NF-kB, TNF-α, IL-1β, and TGF-β increased in the kidneys of C.carpio. Additionally, the expression of SIRT1 decreased, while the expression of other mRNAs increased in kidneys of C. carpio exposed to Cd. According to mRNAs expression in the agomir and Cd treatment, miRNAs inhibit the expressions of target mRNAs. These results demonstrate that miR-217 via SIRT1 plays a regulatory role in the immunotoxicity of Cd to C. carpio.

A primer on metabolic memory: why existing diabesity treatments fail

Despite massive government and private sector investments into prevention of cardiovascular disease, diabetes mellitus and obesity, efforts have largely failed, and the burden of cost remains in the treatment of downstream morbidity and mortality, with overall stagnating outcomes. A new paradigm shift in the approach to these patients may explain why existing treatment strategies fail, and offer new treatment targets. This review aims to provide a clinician-centred primer on metabolic memory, defined as the sum of irreversible genetic, epigenetic, cellular and tissue-level alterations that occur with long-time exposure to metabolic derangements.

Identification of key microRNAs, transcription factors and genes associated with congenital obstructive nephropathy in a mouse model of megabladder

OBJECTIVE

The present study aimed to investigate the molecular mechanism underlying congenital obstructive nephropathy (CON).

METHODS

The microarray dataset GSE70879 was downloaded from the Gene Expression Omnibus, including 3 kidney samples of megabladder mice and 4 control kidneys. Using this dataset, differentially expressed miRNAs (DEMs) were identified between the kidney samples from megabladder mice and controls, followed by identification of the target genes for these DEMs and construction of a DEM and target gene interaction network. Additionally, the target genes were subjected to Gene Ontology and pathway enrichment analyses, and were used for construction of a protein-protein interaction (PPI) network. Finally, regulatory networks were constructed to analyze transcription factors for the key miRNAs.

RESULTS

From 17 DEMs identified between kidney samples of megabladder mice and controls, 3 key miRNAs were screened, including mmu-miR-150-5p, mmu-miR-374b-5p and mmu-miR-126a-5p. The regulatory networks identified vascular endothelial growth factor A (Vegfa) as the common target gene of mmu-miR-150-5p and five transcription factors, including nuclear receptor subfamily 4, group A, member 2 (Nr4a2), Jun dimerisation protein 2 (Jdp2), Kruppel-like factor 6 (Klf6), Neurexophilin-3 (Nxph3) and RNA binding motif protein 17 (Rbm17). The gene encoding phosphatase and tensin homolog (Pten) was found to be co-regulated by mmu-miR-374b-5p and high mobility group protein A1 (Hmga1), whereas the kirsten rat sarcoma viral oncogene (Kras) was identified as a common target gene of mmu-miR-126a-5p and paired box 6 (Pax6).

CONCLUSIONS

In summary, the above-listed key miRNAs, transcription factors and key genes may be involved in the development of CON.

Epigenetics of kidney disease

DNA methylation and histone modifications determine renal programming and the development and progression of renal disease. The identification of the way in which the renal cell epigenome is altered by environmental modifiers driving the onset and progression of renal diseases has extended our understanding of the pathophysiology of kidney disease progression. In this review, we focus on current knowledge concerning the implications of epigenetic modifications during renal disease from early development to chronic kidney disease progression including renal fibrosis, diabetic nephropathy and the translational potential of identifying new biomarkers and treatments for the prevention and therapy of chronic kidney disease and end-stage kidney disease.