Whole-Genome Transcriptome Profiling of Microvascular Free Flaps
Ontology highlight
ABSTRACT: Vascular compromise in microsurgical free flap transfers continues to present devastating outcomes in terms of flap failure and increased operating room costs. Current devices to detect early venous congestion have not become widely accepted because of insufficient sensitivity, incisiveness, or practicality. In our study, we developed a venous obstruction rat model in which the superficial inferior epigastric (SIE) vessels to the lower abdominal flaps was separated and artery or vein was ligated, and the flap reattached. Flaps were harvested 4 hours post-op. Total RNA was isolated and gene expression profiles were compared by Affymetrix Whole Genome 230 2.0. Flaps from groups of Venous or artery congestion (VC or AC, resp.) and sham operation group, were harvested and RNA extraction and hybridization on Affymetrix microarrays. Other controls including histology assays to assure comparable phenotype within groups.
Project description:Vascular compromise in microsurgical free flap transfers continues to present devastating outcomes in terms of flap failure and increased operating room costs. Current devices to detect early venous congestion have not become widely accepted because of insufficient sensitivity, incisiveness, or practicality. In our study, we developed a venous obstruction rat model in which the superficial inferior epigastric (SIE) vessels to the lower abdominal flaps was separated and artery or vein was ligated, and the flap reattached. Flaps were harvested 4 hours post-op. Total RNA was isolated and gene expression profiles were compared by Affymetrix Whole Genome 230 2.0.
Project description:Two matched groups of Heart Failure with reduced ejection fraction patients with no peripheral venous congestion were studied: with recent prior heart failure hospitalization vs. without recent heart failure hospitalization. Peripheral venous congestion was modeled by inflating a cuff around the dominant arm, targeting an ~30mmHg increase in venous pressure (venous stress test). Blood and endothelial cells were sampled before and after 90 minutes of venous stress test.
Project description:Epidemiological studies showed that patients with heart failure frequently develop kidney dysfunction, called cardio-renal syndrome (CRS). Elevated central venous pressure rather than low cardiac output strongly correlates with worsening renal function, and is being increasingly recognized as the pathophysiology responsible for CRS. However, due to the lack of appropriate animal models, the molecular mechanisms underlying the congestion-mediated acceleration of kidney injury, called renal congestion, remain unclear. In the present study, using a novel mouse renal congestion model, we detected injured tubule-specific cell-cell interactions in congestive kidneys and showed that Cellular Communication Network Factor 1 (CCN1) played an important role in this process. Transcriptomics of kidneys with ischemia-reperfusion injury (IRI) and renal congestion revealed the up-regulation of paracrine chemokine-related pathways. The up-regulation of CCN1 was observed in the acute phase after kidney injury with renal congestion. Positive staining for phosphorylated focal adhesion kinase (pFAK), a downstream signaling molecule of CCN1, was noted in fibroblasts at injury sites in congestion-IRI kidneys. CCN1 activated the phosphorylation of FAK and ERK in vitro, which accelerated the migration of fibroblasts and macrophages. We then examined the effects of CCN1 deletion in tubular epithelia on congestion-mediated kidney injury in vivo. pFAK expression in injury sites was down-regulated in CCN1-KO mice, and the congestion-mediated worsening of tissue fibrosis was significantly ameliorated. In conclusion, we herein demonstrated the important role of injured tubule-derived CCN1 on pFAK-mediated fibroblast migration in congestive kidneys. The inhibition of CCN1 has potential as a therapeutic candidate for preventing the transition of renal congestion-mediated kidney injury to fibrosis.
Project description:The number of heart failure (HF) patients is increasing. HF is frequently accompanied by kidney dysfunction and such organ failure is closely related. Recent investigations revealed that increased renal venous pressure, rather than decreased cardiac output, causes the deterioration of kidney function in HF patients; however, the underlying responsible mechanisms are unknown. We demonstrated that reduced blood flow speed in peritubular capillaries (PTCs) by renal congestion and upregulation of nuclear factor-κB (NF-κB) signaling synergistically exacerbate kidney injury. We generated a novel mouse model with unilateral renal congestion by coarctation of the inferior vena cava between renal veins. Intravital imaging highlighted the notable dilatation of PTCs and decreased renal blood flow speed in the congestive kidney. Renal damage after ischemia reperfusion injury was exacerbated in the congestive kidney and accumulation of polymorphonuclear leukocytes (PMNs) within PTCs was observed at the acute phase after injury. Pharmacological inhibition of NF-κB ameliorated renal congestion-mediated exacerbation of kidney injury. In vitro, adhesion of PMNs on the TNFα-stimulated endothelial cells was accelerated by perfusion of PMNs at a slower speed, which was cancelled by the inhibition of NF-κB signaling. Our study demonstrates the importance of slower blood flow accompanying activated NF-κB signaling in the congestive kidney in the exacerbation of renal injury. These mechanisms may explain how increased renal venous pressure in HF patients causes the deterioration of kidney dysfunction. Inhibition of NF-κB signaling may be a therapeutic candidate for the vicious cycle between heart and kidney failure with increased renal venous pressure.
Project description:Vascular calcification (VC) is often associated with cardiovascular and metabolic diseases. However, the molecular mechanisms linking VC to these diseases have yet to be elucidated. Here we report that MDM2-induced polyubiquitination of histone deacetylase 1 (HDAC1) mediates VC. Loss of HDAC1 activity via either chemical inhibitor or genetic ablation enhanced VC. HDAC1 protein, but not mRNA, was reduced in cell and animal calcification models and in human calcified coronary artery. In the calcification-provoking condition, proteasomal degradation of HDAC1 preceded VC. The calcification-provoking condition induced MDM2 E3 ligase, which then resulted in HDAC1 K74 polyubiquitination. Overexpression of MDM2 enhanced VC, whereas loss of MDM2 blunted it. Decoy peptides spanning HDAC1 K74 and RG 7112, an MDM2 inhibitor, prevented VC in vivo and in vitro. These results demonstrate a previously unknown ubiquitination pathway and suggest MDM2-mediated HDAC1 polyubiquitination as a new therapeutic target in VC.
Project description:Vascular calcification (VC) is often associated with cardiovascular and metabolic diseases. However, the molecular mechanisms linking VC to these diseases have yet to be elucidated. Here we report that MDM2-induced polyubiquitination of histone deacetylase 1 (HDAC1) mediates VC. Loss of HDAC1 activity via either chemical inhibitor or genetic ablation enhanced VC. HDAC1 protein, but not mRNA, was reduced in cell and animal calcification models and in human calcified coronary artery. In the calcification-provoking condition, proteasomal degradation of HDAC1 preceded VC. The calcification-provoking condition induced MDM2 E3 ligase, which then resulted in HDAC1 K74 polyubiquitination. Overexpression of MDM2 enhanced VC, whereas loss of MDM2 blunted it. Decoy peptides spanning HDAC1 K74 and RG 7112, an MDM2 inhibitor, prevented VC in vivo and in vitro. These results demonstrate a previously unknown ubiquitination pathway and suggest MDM2-mediated HDAC1 polyubiquitination as a new therapeutic target in VC. Calcification was induced in rat aorta vascular smooth muscle cells with inorganic phosphate (Pi). Total RNA were extracted from the cells 3 and 6 days later. mRNA profile of the sample was compared with normal control.
Project description:Maintenance of cardiomyocyte identity is vital for normal heart development and function. However, our understanding of cardiomyocyte plasticity remains incomplete. Here, we show that sustained expression of the zebrafish transcription factor Nr2f1a prevents the progressive acquisition of ventricular cardiomyocyte (VC) and pacemaker cardiomyocyte (PC) identities within distinct regions of the atrium. Transcriptomic analysis of flow-sorted atrial cardiomyocytes (ACs) from nr2f1a mutant zebrafish embryos showed increased VC marker gene expression and altered expression of core PC regulatory genes, including decreased expression of nkx2.5, a critical repressor of PC differentiation. At the arterial (outflow) pole of the atrium in nr2f1a mutants, cardiomyocytes resolve to VC identity within the expanded atrioventricular canal. However, at the venous (inflow) pole of the atrium, there is a progressive wave of AC transdifferentiation into PCs across the atrium toward the arterial pole. Restoring Nkx2.5 is sufficient to repress PC marker identity in nr2f1a mutant atria and analysis of chromatin accessibility identified a Nr2f1a-dependent nkx2.5 enhancer expressed in the atrial myocardium directly adjacent to PCs. CRISPR/Cas9-mediated deletion of the putative nkx2.5 enhancer leads to a loss of Nkx2.5-expressing ACs and expansion of a PC reporter, supporting that Nr2f1a limits PC differentiation within venous ACs via maintaining nkx2.5 expression. The Nr2f-dependent maintenance of AC identity within discrete atrial compartments may provide insights into the molecular etiology of concurrent structural congenital heart defects and associated arrhythmias.
Project description:Chronic cerebral hypoperfusion, induced by bilateral common carotid artery stenosis (BCAS), models the underlying cause of vascular dementia. We used single-cell transcriptomics to identify endothelial subtype-specific responses to BCAS in the mouse prefrontal cortex. The most dynamic molecular changes were observed in venous endothelial cells, with upregulated pathways linked to vascular remodeling and angiogenesis. Cerebral hypoperfusion upregulated expression of the endothelial PAS domain protein 1 (Epas1 ) gene in venous endothelial cells, while exposure of human venous endothelial cells to 1% oxygen in vitro caused sustained nuclear translocation of EPAS1. Pharmacological inhibition of EPAS1 reduced abnormal venous sprouting and concomitantly dampened microglia activation. Among human subjects with mild cerebrovascular disease, there was a negative correlation observed between their circulating damaged endothelial cells (CECs) and cerebral blood flow levels. In addition, elevated levels of venous-origin CECs were detected in subjects with white matter lesions and were notably linked to poorer overall cognitive function. We conclude that venous endothelial cells are potential therapeutic targets for vessel normalization to mitigate vascular cognitive impairment caused by chronic cerebral hypoperfusion.