Whole-Genome Transcriptome Profiling of Microvascular Free Flaps
Ontology highlight
ABSTRACT:
ORGANISM(S): Rattus norvegicus
PROVIDER: GSE35270 | GEO | 2016/07/24
SECONDARY ACCESSION(S): PRJNA152845
REPOSITORIES: GEO
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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. 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.
2016-07-24 | E-GEOD-35270 | biostudies-arrayexpress
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.
2023-08-28 | GSE237856 | GEO
Project description:The random-pattern skin flap is a crucial technique in reconstructive surgery and flap necrosis caused by ischemia/reperfusion injury is a major postoperative complication. Herein, we investigated the mechanism of mitophagy induced by Melatonin (ML) and its effect on the survival of skin flaps. Our results demonstrated that ML could activate mitophagy, ameliorate oxidative stress and alleviate apoptosis in TBHP-stimulated human umbilical vein endothelial cells in vitro. Inhibiting ML-induced mitophagy considerably abolished its protective effects. Moreover, knockdown of Parkin by siRNA inhibited ML-induced mitophagy, and subsequently exacerbated oxidative stress and apoptosis. Further study demonstrated that inhibition of AMPK reversed these protective effects of ML and downregulated the expression of TFEB. In the vivo study, ML effectively promoted flap survival by activating mitophagy and subsequently ameliorating oxidative stress and mitigating apoptosis. These results established that ML is a potent agent capable for increasing random-pattern skin flap survival by activating Parkin-dependent mitophagy through the AMPK-TFEB signaling pathway.
2022-06-29 | GSE203609 | GEO
Project description:We have previously demonstrated that preconditioning flap donor with electrical stimulation (ES) could increase the survival area of pedicled perforator flaps in a rat model. However, the detailed molecular mechanisms remain unclear. In this study, we first verified the effects of ES through in vivo and in vitro experiments. Then we explored the underlying mechanisms in vitro. The results indicated that preconditioning with ES could not only increase the flap survival area but mitigate human umbilical vein endothelial cells (HUVECs) dysfunction. Furthermore, low level reactive oxygen spices (ROS) were produced in HUVECs after ES, serving assignaling molecule to activate the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HOl) pathway. Then ROS scavenger was used to attenuate thegeneration of ROS, resulting that activation of the Nrf2/HOl pathway was inhibited. These results suggest that ROS/Nrf2/HO1 pathway may play pivotal roles in the ES pretreatment induced flap survival.
2024-11-01 | GSE280048 | GEO
Project description:Prior to ligation, each Okazaki fragment synthesized on the lagging strand in eukaryotes must be nucleolytically processed. Nuclease cleavage takes place in the context of 5’ flap structures generated via strand-displacement synthesis by DNA polymerase delta. At least three DNA nucleases: Rad27 (Fen1), Dna2, and Exo1, have been implicated in processing Okazaki fragment flaps. However, neither the contributions of individual nucleases to lagging-strand synthesis nor the structure of the DNA intermediates formed in their absence have been clearly defined in vivo. By conditionally depleting lagging-strand nucleases and directly analyzing Okazaki fragments synthesized in vivo in S. cerevisiae, we conduct a systematic evaluation of the impact of Rad27, Dna2 and Exo1 on lagging-strand synthesis. We find that Rad27 processes the majority of lagging-strand flaps, with a significant additional contribution from Exo1 but not from Dna2. When nuclease cleavage is impaired, we observe a reduction in strand-displacement synthesis as opposed to the widespread generation of long Okazaki fragment 5’ flaps, as predicted by some models. Further, using cyclin-controlled constructs, we demonstrate that both the nucleolytic processing and the ligation of Okazaki fragments can be uncoupled from DNA replication and delayed until after synthesis of the majority of the genome is complete.
2018-08-04 | GSE118078 | GEO
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.
2024-02-16 | GSE166838 | GEO
Project description:Objective/Hypothesis: To assess the efficacy and mechanism of action of a novel approach to mitigate acute and chronic radiation toxicity in a validated animal model. We propose that synthetic triterpenoid RTA-408, an Nrf2 activator, activates additional protective pathways which stabilize soft tissue during radiation, thereby reducing necrosis and improves surgical outcomes in a subsequently created axial rotational flap. Methods: Experimental animal study utilizing Sprague-Dawley rats were divided into 3 cohorts: (i) radiation + DMSO (inert vehicle), (ii) radiation + RTA-408 (therapeutic drug), and (iii) no radiation + DMSO. Two main groups of rats were utilized in these experiments: (i) rotational flap experiment (n=40) and (ii) transcriptome analysis (n=9). In the first experiment all animals in the radiation cohorts underwent 40 Gy of radiation to the soft tissue of the abdomen. Then all three cohorts underwent surgery with construction of an inferior epigastric axial rotational flap, which was performed 30 days after resolution of acute injury from radiation in the radiation groups. Percentage of flap necrosis, the primary endpoint, was calculated by standardized measurement of tissue necrosis by blinded observers and vascular density measured by CD31 staining. In a second experiment, an additional three cohorts, with identical treatment as described above underwent serial punch biopsies of the abdominal skin before, during, and after radiation and drug/vehicle control treatment. Transcriptome analysis utilizing gene set enrichment analysis and digital PCR were performed at the various timepoints. Results: In the first experiment, 40 rats were divided into the three groups and underwent treatment accordingly. The average flap necrosis was 20% (95% CI, 16-45%) in the radiation control group, 3% (95% CI, 0-11%) in the non-irradiated control, and 3% (95% CI, 0.2-10%) in the radiation group treated with RTA-408. Vascular density was preserved in the treatment group as compared to the radiated control. Nine rats were included in the second experiment, and transcriptome analyses in the treatment group revealed robust activation of antioxidant pathways with induced expression of genes associated with hypoxia and adipogenesis/angiogenesis. Conclusions: Administration of RTA-408 during radiation treatment in a rat model resulted in transcriptome changes which appear to mitigate the toxic effects of radiation, preserving capillary networks and improving flap survival and tissue healing after subsequent surgery. Such reductions in toxicity may have broad implications for functional outcomes and salvage surgery following therapeutic irradiation.
2021-09-17 | GSE184308 | GEO
Project description:Diabetes and obesity are widespread diseases with signifciant socioeconomic implications. We used three different types of human adipose tissue (epigastric, visceral, and subcutaneous) in order to determine differences in global gene expression between these adipose depots in severely obese patients. In this dataset, we include the expression data obtained from three types of adipose tissue; epigastric, subcutaneous, and visceral all obtained through open gastric bypass surgery. 18 total samples were analyzed. Tissues were paired together to run on one genechip, with three pairs of epigastric, three pairs of subcutaneous, and three pairs of visceral were ran on nine genechips. Comparisons of gene expression in the form of fold changes between pairs of adipose types (i.e., subcutaneous/epigastric, visceral/epigastric, and subcutaneous/visceral) were completed by Spotfire Analysis.
2013-08-22 | E-GEOD-42715 | biostudies-arrayexpress
Project description:In patients with severe kidney disease AVF are surgically placed in order to create good access for hemodialysis. In these dialysis patients the failure rates of AVF can be as high as 24% within 6 months after surgery, causing ineffective dialysis and necessitating additional clinical interventions. The pathological processes known to lead to AVF failure are beginning to be unravelled include the formation of venous neointimal hyperplasia (VNIH), thrombosis (Chang et al. PMID 16105066), and venous stenosis (Kanterman et al. PMID7892454, Tang et al. 1998), resulting in a reduced blood flow through the fistula. We established a rat model for AVF failure in human kidney dialysis patients. The characterization of this model has been previously described (Globerman et al. 2011, PubmedID:22002501). In this model the AVFs are surgically constructed in the right leg by connecting the superficial epigastric vein SEV to the common femoral artery (CFA), resulting in exposure of the SEV to arterial pressure with pulsatile and low resistant flow patterns (Globerman et al. 2011, PMID22002501). In the present study we utilized this AVF model in order to assess the effects of arterialized flow, with consequent pathological changes of the vessel wall due to surgical AVF instalment, on the transcriptome of endothelium from the SEV. Within the SEV these pathologies of the vessel wall include the formation of NIH in the main branch, and stenosis in the side branches. By employing this rat model we assessed the changes of the endothelial transcriptome in relation to these pathologies in order to gain mechanistic understanding of the potential roles of venous endothelium in AVF failure, as well as to identify potential biomarkers preceding AVF failure. AVF surgery was performed on N=6 rats, and 13-14 days after surgery the rats were sacrificed. AVFs were extracted from the rats, and microarray transcriptome analyses were performed on luminal endothelial cells that isolated from four different sites of the AVF by employing Laser Capture Microdissection (LCM). These sites included (i) N=5 AVF sections of the superficial epigastric vein (SEV) with neointimal hyperplasia (NIH), (ii) N=3 AVF sections of SEV side branches with luminal stenosis, (iii), N=6 sections of the SEV located distally from a ligation thereby omitting exposure to arterialized flow and consequently preventing the development of NIH or stenosis, and (iv) N=3 sections of the AVF common femoral artery without signs of NIH or stenosis.
2013-10-01 | E-GEOD-46126 | biostudies-arrayexpress