Project description:Recently, mitochondrial-nuclear interaction in aging has been widely studied. However, the nuclear genome controlled by natural mitochondrial variations that influence aging has not been comprehensively understood so far. We hypothesized that mitochondrial polymorphisms could play critical roles in the aging process, probably by regulation of the whole-transcriptome expression. Our results showed that mitochondria polymorphisms not only decreased the mitochondrial mass but also miRNA, lncRNA, mRNA, circRNA and metabolite profiles. Furthermore, most genes that are associated with mitochondria show age-related expression features (P = 3.58E-35). We also constructed a differentially expressed circRNA-lncRNA-miRNA-mRNA regulatory network and a ceRNA network affected by the mitochondrial variations. In addition, Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that the genes affected by the mitochondrial variation were enriched in metabolic activity. We finally constructed a multi-level regulatory network with aging which affected by the mitochondrial variation in Caenorhabditis elegans. The interactions between these genes and metabolites have great values for further aging research. In sum, our findings provide new evidence for understanding the molecular mechanisms of how mitochondria influence aging.
Project description:To identify novel aging-related miRNAs, we initially established a physiological aging mouse model (20-month old male C57BL/6 mouse), compared with 2-month old male C57BL/6 mouse. Then, the Agilent miRNA microarray was performed to profile miRNA expression levels in kidney from 20-month old male C57BL/6 mouse (designated as Aging) and 2-month old male C57BL/6 mouse (designated as Young). Overall design: The miRNA profile was measured in 2-month and 20-month old male C57BL/6. Microarray assay was performed in triplicates, utilizing three independent sets of RNA preparations from each group (young or aging mouse).
Project description:<h4>Background</h4>This study aims to analyze sex differences in mice aging kidney. We applied a proteomic technique based on subfractionation, and liquid chromatography coupled with 2-DE. Samples from male and female CD1-Swiss outbred mice from 28 weeks, 52 weeks, and 76 weeks were analysed by 2-DE, and selected proteins were identified by matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS).<h4>Results</h4>This proteomic analysis detected age-related changes in protein expression in 55 protein-spots, corresponding to 22 spots in males and 33 spots in females. We found a protein expression signature (PES) of aging composed by 8 spots, common for both genders. The identified proteins indicated increases in oxidative and proteolytic proteins and decreases in glycolytic proteins, and antioxidant enzymes.<h4>Conclusion</h4>Our results provide insights into the gender differences associated to the decline of kidney function in aging. Thus, we show that proteomics can provide valuable information on age-related changes in expression levels of proteins and related modifications. This pilot study is still far from providing candidates for aging-biomarkers. However, we suggest that the analysis of these proteins could suggest mechanisms of cellular aging in kidney, and improve the kidney selection for transplantation.
Project description:Kidney miRNA expression was examined in F344 rats at 2, 5, 6, 8, 15, 21, 78, and 104 weeks of age in both sexes using Agilent miRNA microarrays. 311 miRNAs were found to be expressed in at least one age and sex. Filtering criteria of ?1.5 fold change and ANOVA (FDR <5%) revealed 174 differentially expressed miRNAs in the kidney; 173 and 34 miRNAs exhibiting age and sex effects, respectively. Principal component analysis revealed age effects predominated over sex effects, with 2 week miRNA expression being much different from other ages. No significant sexually dimorphic miRNA expression was observed from 5 to 8 weeks, while the most differential expression (13 miRNAs) was observed at 21 weeks. Potential target genes of these differentially expressed miRNAs were identified. Pathway analysis was used to investigate the possible roles of these target genes in age- and sex-specific differences. Untreated male and female F344 rats from 2, 5, 6, 8, 15, 21, 78, and 104 weeks of age (n=5) were sacrificed by CO2 asphyxiation, whole kidneys collected and homogenized, total RNA, including small RNA fraction, was used for miRNA expression arrays (Agilent).
Project description:Kidney aging leads to an increased incidence of end-stage renal disease (ESRD) in the elderly, and aging is a complex biological process controlled by signaling pathways and transcription factors. Podocyte senescence plays a central role in injury resulting from kidney aging. Here, we demonstrated the critical role of C/EBP? in podocyte senescence and kidney aging by generating a genetically modified mouse model of chronological aging in which C/EBP? was selectively deleted in podocytes and by overexpressing C/EBP? in cultured podocytes, in which premature senescence was induced by treatment with adriamycin. Moreover, we illuminated the mechanisms by which podocyte senescence causes tubular impairment by stimulating HK-2 cells with bovine serum albumin (BSA) and chloroquine. Our findings suggest that C/EBP? knockout in podocytes aggravates podocyte senescence through the AMPK/mTOR pathway, leading to glomerulosclerosis, and that subsequent albuminuria exacerbates the epithelial-mesenchymal transdifferentiation of senescent tubular cells by suppressing autophagy. These observations highlight the importance of C/EBP? as a new potential target in kidney aging.
Project description:(1) Background: Lipopolysaccharide (LPS)-induced systemic inflammation is associated with septic acute kidney injury (AKI). We investigated the time-dependent miRNA expression changes in the kidney caused by LPS. (2) Methods: Male outbred NMRI mice were injected with LPS and sacrificed at 1.5 and 6 h (40 mg/kg i.p., early phase, EP) or at 24 and 48 h (10 mg/kg i.p., late phase, LP). The miRNA profile was established using miRCURY LNA™ microarray and confirmed with qPCR. Total renal proteome was analyzed by LC-MS/MS (ProteomeXchange: PXD014664). (3) Results: Septic AKI was confirmed by increases in plasma urea concentration and in renal TNF-? and IL-6 mRNA expression. Most miRNAs were altered at 6 and 24 h and declined by 48 h. In EP miR-762 was newly identified and validated and was the most elevated miRNA. The predicted target of miR-762, Ras related GTPase 1B (Sar1b) was downregulated. In LP miR-21a-5p was the most influenced miRNA followed by miR-451a, miR-144-3p, and miR-146a-5p. Among the potential protein targets of the most influenced miRNAs, only aquaporin-1, a target of miR-144-3p was downregulated at 24 h. (4) Conclusion: Besides already known miRNAs, septic AKI upregulated miR-762, which may regulate GTP signaling, and miR-144-3p and downregulated its target, aquaporin-1.
Project description:PURPOSE OF REVIEW:Transcriptome analysis of human kidney samples provides an integrated output of genetic, physiological, or environmental inputs. This review summarizes recent findings including gene expression and genetic variation integration, bulk and single cell gene expression analysis, and describes how such studies have improved our understanding of kidney disease development. RECENT FINDINGS:Bulk or whole tissue analysis of patient kidney samples identified a large number of genes, whose levels correlate with kidney function and/or structural damage. These genes were enriched for metabolic and immune functions. Using expression quantitative trait analysis, genetic variations-driven gene expression can be identified. Recent developments in single cell sequencing defined cell-type-specific gene expression changes and highlighted specific cell types for disease development. SUMMARY:Recent advancement in whole tissue transcriptomics, specifically incorporating genotype information and single cell data have been powerful to identify kidney disease-associated genes, pathways, and cell types.
Project description:Kidneys age at different rates, such that some people show little or no effects of aging whereas others show rapid functional decline. We sequentially used transcriptional profiling and expression quantitative trait loci (eQTL) mapping to narrow down which genes to test for association with kidney aging. We first performed whole-genome transcriptional profiling to find 630 genes that change expression with age in the kidney. Using two methods to detect eQTLs, we found 101 of these age-regulated genes contain expression-associated SNPs. We tested the eQTLs for association with kidney aging, measured by glomerular filtration rate (GFR) using combined data from the Baltimore Longitudinal Study of Aging (BLSA) and the InCHIANTI study. We found a SNP association (rs1711437 in MMP20) with kidney aging (uncorrected p = 3.6 x 10(-5), empirical p = 0.01) that explains 1%-2% of the variance in GFR among individuals. The results of this sequential analysis may provide the first evidence for a gene association with kidney aging in humans.