Project description:Hypertension is a pathological condition of persistent high blood pressure (BP) of which the underlying mechanisms remain largely obscure. Here, we show that the afferent nerves in perirenal adipose tissue are a regulatory site in triggering and maintaining pathological high BP, without affecting physiological BP. Bilateral perirenal adipose tissue (PRAT) ablation leads to a long-term and effective reduction of BP in spontaneous hypertensive rats (SHR) and high fat and high salt diet fed rats, but has no effect on normal BP in control Wistar-Kyoto or control SD rats. Moreover, gain- and loss-of-function studies show that augmented activities of L1-L2 dorsal root ganglia (DRG) neurons are responsible for hypertension in SHR. Further, L1-L2 DRG neuron transcriptomics uncovers significant changes in neuron development, remodeling, and plasticity. Importantly, calcitonin gene-related peptide (CGRP), a systemic vasodilator, is induced after PRAT ablation. We went on to show that CGRP antagonist blocks the BP-lowering effect of PRAT ablation. CGRP is therefore a key endogenous suppressor of hypertension that is sequestered by anti-hypertensive PRAT in SHRs. Taken together, we identify PRAT afferent nerves as a pathological node of hypertension that sustains high BP via suppressing CGRP, thereby providing a therapeutic target to tackle primary hypertension.
Project description:To investigate the potential function of lncRNAs in Schwann cell (SCs) response to sciatic nerve damage and repair, we extracted the total RNA of crushed sciatic nerves and intact contralateral nerves for RNA-sequencing (RNA-seq). A total of 98 differentially expressed lncRNAs (including 46 up-regulated and 52 down-regulated lncRNAs) and 77 differentially expressed mRNAs (including 55 up-regulated and 22 down-regulated mRNAs) were identified between crushed sciatic nerves and normal control (log 2 FC > 1 and p < 0.001).
Project description:EAE mice were injected with LPC 18:1 and Isobaric C13-His at the optic nerve when they exhibited a clinical score of 2. Visual function was assessed via pattern electroretinogram and optic nerves were harvested 12 days post optic nerve injection. Optic nerves were processed for mass spectrometry to identify the integration of C13-His in newly synthesized proteins.
Project description:Abstract: Background and aims: Portal hypertension (PH) is the most frequent and severe clinical syndrome associated to chronic liver disease (CLD), defined by a pathological increase in the hepatic venous pressure gradient (HVPG). Considering the known mechanobiological effects of hydrostatic pressure and shear stress on endothelial cells, we hypothesized that PH could not only be a consequence of, but significantly influence the phenotype of liver sinusoidal endothelial cells (LSECs) during disease progression. The aim of this study was to investigate the effects of pathological hydrodynamic pressure on LSECs and to identify endothelial-derived biomarkers of PH. Methods: Primary LSECs were cultured under normal or increased hydrodynamic pressure within a pathophysiological range (1 vs 12 mmHg) using a microfluidic liver-on-a-chip device. RNAseq was used to identify pressure-sensitive genes, which were validated in liver biopsies from two independent cohorts of CLD patients with PH (n=73) vs subjects without PH (n=23). Biomarker discovery was performed in plasma from a third independent cohort of 64 patients (46 with PH vs 18 w/o). Results: Transcriptomic analysis revealed a marked deleterious effect of pathological pressure in LSECs and identified chromobox 7 (CBX7) as a key transcription factor diminished by pressure. Hepatic CBX7 downregulation was validated in patients with PH and significantly correlated with HVPG. MicroRNA 181a-5p was identified as pressure-induced upstream regulator of CBX7. Analysis of two downstream targets of CBX7, ECAD and SPINK1, were found increased in the bloodstream of patients with PH and were highly predictive of PH and clinically significant PH, with a sensitivity of 91.3% and 91.4% respectively. Conclusions: We describe the detrimental effects of increased hydrodynamic pressure on the sinusoidal endothelium, identify CBX7 as a pressure-sensitive transcription factor, and propose that the combination of two of its reported products could be used as plasma biomarkers of PH.
Project description:Optic nerves are an accessible part of the CNS, providing a source of glia without the presence of neuronal cell bodies. Therefore, an analysis was carried out of gene expression in optic nerves at P4, before myelination begins and at P10, when myelination is very actively proceeding. The goal was to obtain a profile of the changing gene expression that accompanies this transition from unmyelinated CNS nerve to myelinated nerve. Two microarray experiments were combined here. In the first, RNA was prepared from the optic nerves of 75 P4 C57BL/6J mice and 70 P10 C57BL/6J mice. In the second experiment, RNA was prepared from the optic nerves of 55 P4 C57BL/6J mice and two groups of 50 P10 C57Bl/6J mice. In total, there are 2 P4 RNA samples and 3 P10 RNA samples being hybridized to Affymetrix GeneChip 430A for Mouse Expression.
Project description:We performed gene expression pofiling of Zeb2cKO and control sciatic nerves and identified significantly changed genes ZEB2 is also known as SIP1 4 RNA-Seq samples from P7 sciatic nerves of Ctrl and Zeb2 cKO mice (duplicatess, Ctrl and cKO)
Project description:Cardiac hypertrophy can lead to heart failure, and is induced either by physiological stimuli eg postnatal development, chronic exercise training or pathological stimuli eg pressure or volume overload. Majority of new therapies for heart failure has mixed outcomes. A combined mouse model and oligo-array approach are used to examine whether phosphoinositide 3-kinase (p110-alpha isoform) activity is critical for maintenance of cardiac function and long-term survival in a setting of heart failure. The significance and expected outcome are to recognise genes involved in models of heart failure ie pathological- vs physiology-hypertrophy, and examine the molecular mechanisms responsible for such activity. Growth of the heart can be induced by physiological stimuli e.g., postnatal development, chronic exercise training, or pathological stimuli e.g., pressure or volume overload. Physiological hypertrophy (“good”) is characterised by a normal organisation of cardiac structure, and normal or enhanced cardiac function. In comparison, pathological hypertrophy (”bad”) is associated with fibrosis, cardiac dysfunction, and increased morbidity and mortality. The mechanistic process which allows the heart to enlarge in response to physiological stimuli while maintaining normal or enhanced function is of great clinical relevance because one potential therapeutic strategy is to inhibit the pathological growth process while augmenting the physiological growth process. One of the major process that regulate heart size is by phosphoinositide 3-kinase (PI3K). Thus the end goal of this project is to determine whether the p110 alpha isoform of PI3K could be a potential tool for augmenting physiological growth and improving cardiac function of the failing diseased heart, and to examine the underlying mechanisms responsible. Keywords: Disease progression analysis
Project description:In this study, we analyzed the transcriptome profiles of mouse sciatic nerves subjected to crush injuries after inducible deletion of Raptor conditionally in Schwann cells (using a PLPCreERT2-driven recombination of floxed alleles) as compared to controls (floxed Raptor homozygous, PLPCreERT2-negative). The transcriptome profiles of the contralateral uninjured nerves were also analyzed. Differentially expressed genes, defined as genes with a fold change>1.2 and fold discovery rate <0.05, in injured and contralateral nerves of mutants compared to controls were subjected to gene ontology analysis. Additionally, differentially expressed genes in injured mutants nerves as compared to injured control nerves were further analyzed for enrichment of transcription factor binding motifs in the corresponding promoter regions using the bioinformatic tool Homer version 4.9 (Heinz et al., Molecular Cell, 2010)