Project description:Maternal ketosis during pregnancy can impact fetal development, yet its effects on kidney development are not well understood. This study investigates the impact of maternal ketosis on offspring nephrogenesis using two mouse models: a ketogenic diet and β-hydroxybutyrate supplementation. Pregnant mice were subjected to either intervention from conception until birth. Offspring kidneys were analyzed at birth and in adulthood for nephron number, glomerular density, and renal function. Nephron progenitor cells (NPCs) were isolated from embryonic kidneys and analyzed using RNA sequencing, immunostaining, and quantitative PCR. Both ketosis models resulted in significantly reduced glomerular density at birth and a 25% decrease in nephron number in adult offspring, accompanied by impaired renal function. RNA sequencing revealed over 1,000 differentially expressed genes in the ketogenic diet group and 164 in the β-hydroxybutyrate group, with 67 overlapping genes. Pathway analysis showed downregulation of cell cycle and Myc target pathways, and upregulation of inflammatory pathways in both models. Immunostaining confirmed a 40% reduction in NPC proliferation and decreased c-Myc expression under ketotic conditions. Additionally, ketosis increased TNFα expression and activated the NFκB pathway in NPCs. These findings provide the first evidence linking maternal ketosis to impaired nephrogenesis, demonstrating a negative impact on offspring kidney development by altering NPC proliferation, Myc signaling, and inflammatory responses. This study highlights potential risks associated with ketogenic diets or other ketosis-inducing conditions during pregnancy.
Project description:Hepatic molecular adaptations underlying periparturient metabolic diseases such as ketosis in dairy cows are largely unknown. We used a simple model for induction of ketosis to examine liver gene expression profiles using a microarray consisting of 13,257 annotated cattle oligonucleotides. At 4 days post-partum, 7 cows classified as healthy after a physical examination were fed at 50% of intake at day 4 from day 5 to signs of ketosis or until 14 days post-partum. Another group of 7 healthy cows served as controls. Liver was biopsied at 9-14 (ketosis) or 14 days post-partum (controls). More than 9,000 sequences represented on the microarray were expressed in liver. Keywords: disease state analysis
Project description:Hypoxia-induced intrauterine growth restriction increases the risk for chronic diseases in adults, affecting more than 140 million high altitude residents worldwide. Still, not much is known about the fetal mechanisms that prone these individuals to disease. Using bottom-up proteomics and the kidney as a readout, we delineated a dichotomous response to chronic hypoxic stress, comprising mechanisms that promote survival, but also induce premature senescence. Combined outcome is the manifestation of a predetermined aging phenotype already during fetal development. This aging phenotype is associated with a characteristic biomarker profile in tissue and blood serum samples, exploitable for targeting and monitoring disease.
Project description:Human kidney is a major metabolic organ, which plays a crucial role in regulating homeostasis of human body. However, gene expression characterizations of human fetal kidney development is still not fully explored. Here, we used single-cell RNA-seq to analyze more than 3,000 individual renal cells of human fetal kidneys covering over four months of development in vivo.We found co-expression of self-renewal and differentiation genes in cap mesenchyme, progenitors differed from that of mouse as they persistently express SIX1 throughout the renal morphogenesis. Besides, we recapitulated the transcription factors and signaling pathways potentially important for segmentation of nephron tubule. Furthermore, we explored the human specific features of the heterogeneous collecting duct epithelium. We also dissected the metabolism signatures of fetal kidney as well as the extracellular matrix composition of glomerulus mesangium. Eventually, we identified novel markers for renal tubules. Our study highlights the gene expression features of human fetal kidney development, which will contribute to dissecting the mechanisms of renal dysplasia and congenital nephrotic disease.
Project description:Little is known about the repertoire of nonhuman primate kidney genes expressed throughout development. The present work establishes an understanding of the primate renal transcriptome at different stages of fetal development and defines the framework of gene expression in the context of renal maturation, which provides a basis for identifying deviations in transcriptome expression resulting from suboptimal conditions during renal development. The baboon kidney transcriptome was characterized at 60 days gestation (DG), 90DG, 125DG, 160DG and adulthood (6-12 years) using human genome arrays to identify differential gene expression in the context of biological pathways and hierarchical clusters. Whole genome expression profiling showed 11,331 genes that were expressed during kidney development, 4,698 of which were differentially expressed among the developmental time points. Pathway analysis indicated activation of annotated pathways previously reported to be important to kidney development and pathways not reported as relevant to kidney development. QRT-PCR for genes central to these pathways validated expression profiles and revealed differences between males and females at specific times in gestation. Hierarchical clustering indicated that two clusters best fit the data, one containing genes that increased in expression from 60DG to adult and one that decreased. Cluster analysis also revealed gene splice variants with discordant expression profiles during development. For example, SMAD4, which is central to Wnt signaling, TGF-β signaling and cell cycle, showed up-regulation of the full-length splice variant during development and down-regulation of a shorter variant that is missing DNA binding and protein heterotrimerization domains suggesting decreased inhibition of cell proliferation, which may impact renal cell number and maturation. This study provides the first detailed genetic analysis of the developing primate kidney, and our findings of discordant expression of gene splice variants suggest that gene arrays likely provide a simplified view and demonstrate the need to study the fetal renal proteome.
Project description:Contradictorily, both up- and downregulation of miR-25 can reverse heart failure. Importantly, these findings were based on the same animal model of pressure overloaded transverse aortic constriction (TAC) mice. How can we explain and, if possible, reconcile these two conflicting findings? Heart failure is a multi-step process that involves multiple organs, and we hypothesized that determining whether altering miR-25 alone could induce heart failure should provide a mechanistic basis for miR-25âs action in this process. Here, we show that overexpression of miR-25 in normal mice caused cardiomyocyte fibrosis and apoptosis but no obvious kidney impairment. By contrast, inhibition of miR-25 in normal mice led to hypertension, mild heart dilation, and severe kidney dysfunction. With the expectation that restoring miR-25 might ameliorate kidney injury, we demonstrated that increasing miR-25 reversed proteinuria and kidney fibrosis in diabetic nephropathy. MiR-25 expression in humans is initially decreased at the onset of heart failure but is later increased in end-stage heart failure. RNA sequencing of mouse kidneys with elevated and reduced miR-25 identified distinct alterations of a number of putative miR-25 target mRNAs, including those involved in the Ras signaling pathway, oxidant stress. In summary, differences in miR-25 expression during different stages of heart disease and its distinct roles in the heart and kidney, offer a new perspective for the role of miR-25 function in heart failure, which may begin to resolve this catch-22. Detect the mRNA alteration in wildtype and miR-25 agomir or antagomir treated mice
Project description:Acute fetal hypoxia is a form of fetal stress that stimulates renal vasoconstriction and ischemia as a consequence of the physiological redistribution of combined ventricular output. We have demonstrated that hypoxia in late ovine gestation induces inflammation in the brain that is ameliorated by treatment with ketamine. We hypothesized that the fetal kidney would also respond to hypoxia with an increase in the expression of inflammatory genes, and that ketamine (an N-Methyl-D-aspartate receptor antagonist) would reduce or block this response. Enriched biological processes for the 427 upregulated genes were immune and inflammatory responses and for the 946 down-regulated genes were metabolic processes. Ketamine countered the effects of hypoxia on upregulated immune/inflammatory responses as well as the down-regulated metabolic responses. We conclude that our transcriptomics modeling predicts that hypoxia activates inflammatory pathways and reduces metabolism in the fetal kidney cortex, and ketamine blocks or ameliorates this response. The results suggest that ketamine may have therapeutic potential for protection from ischemic renal damage.
Project description:Acute fetal hypoxia is a form of fetal stress that stimulates renal vasoconstriction and ischemia as a consequence of the physiological redistribution of combined ventricular output. We have demonstrated that hypoxia in late ovine gestation induces inflammation in the brain that is ameliorated by treatment with ketamine. We hypothesized that the fetal kidney would also respond to hypoxia with an increase in the expression of inflammatory genes, and that ketamine (an N-Methyl-D-aspartate receptor antagonist) would reduce or block this response. Enriched biological processes for the 427 upregulated genes were immune and inflammatory responses and for the 946 down-regulated genes were metabolic processes. Ketamine countered the effects of hypoxia on upregulated immune/inflammatory responses as well as the down-regulated metabolic responses. We conclude that our transcriptomics modeling predicts that hypoxia activates inflammatory pathways and reduces metabolism in the fetal kidney cortex, and ketamine blocks or ameliorates this response. The results suggest that ketamine may have therapeutic potential for protection from ischemic renal damage. At the time of surgery, fetuses were randomly assigned to one of the four groups (n=3-4/group): normoxic control, normoxia+ketamine, hypoxic control, and hypoxia+ketamine. Hypoxia was induced for 30 min in chronically catheterized fetal sheep (125±3 d; term=145-147d), with or without ketamine (3 mg/kg) administered intravenously to the fetus 10 min prior to hypoxia. Fetuses were euthanized 24 hours after the onset of hypoxia, and the kidney cortex were collected for RNA extraction and gene array studies. Gene expression was analyzed using ovine Agilent 15.5 k array and validated with qPCR. Significant differences in gene expression between groups were determined with t-statistics using the limma package for R (Pâ¤0.05).
Project description:Purpose: The 10x Genomics Visium platform allows us to define the spatial topography of gene expression and provides detailed molecular maps that overcome limitations associated with sn/scRNA-seq and microscopy-based spatial transcriptomics methods. The goals of this study are to compare and identify unique transcriptome profiling (RNA-seq) signature between unfavorable and favorable Wilms Tumors and against human fetal kidney. Methods: Human fetal kidney and Wilms tumor spatial topography of gene expression were generated using the 10X Visium platform Results: Using an optimized data analysis workflow, we mapped the reads to the hg38 genome build and grouped the spots into 9 clusters based on gene expression profiles. Conclusion: Our study represents the first implement of Visium technology in human fetal kidney and Wilms Tumor tissue, providing a number of important functional insights about the spatial and molecular definitions of cell populations across human fetal kidney and different subtypes of Wilms Tumor through analyzing gene expression within the intact spatial organization of the human samples.