Time course of changes in collateral blood flow and isolated vessel size and gene expression after femoral artery occlusion in rats

2004 ◽  
Vol 287 (6) ◽  
pp. H2434-H2447 ◽  
Author(s):  
Barry M. Prior ◽  
Pamela G. Lloyd ◽  
Jie Ren ◽  
Han Li ◽  
H. T. Yang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Blood Flow ◽  
Growth Factor ◽  
Time Course ◽  
Collateral Blood Flow ◽  
Collateral Vessel ◽  
Low Pressures ◽  
Over Time ◽  
Calf Muscles

The objectives of this study were to assess the time course of enlargement and gene expression of a collateral vessel that enlarges following occlusion of the femoral artery and to relate these responses to the increases in collateral-dependent blood flow to the calf muscles in vivo. We employed exercise training to stimulate collateral vessel development. Rats were exercise trained or kept sedentary for various times of up to 25 days postbilateral occlusion ( n = ∼9/time point). Collateral blood flow to the calf muscles, determined with microspheres, increased modestly over the first few days to ∼40 ml·min−1·100 g−1 in sedentary animals; the increase continued over time to ∼80 ml·min−1·100 g−1 in the trained animals. Diameters of the isolated collateral vessels increased progressively over time, whereas an increased vessel compliance observed at low pressures was similar across time. These responses were greater in the trained animals. The time course of upregulation of vascular endotheial growth factor and placental growth factor, and particularly endothelial nitric oxide synthase and fms-like tyrosine kinase 1, mRNAs in the isolated collateral vessel implicates these factors as integral to the arteriogenic process. Collateral vessel enlargement and increased compliance at low pressures contribute to the enlarged circuit available for collateral blood flow. However, modulation of the functioning collateral vessel diameter, by smooth muscle tone, must occur to account for the observed increases in collateral blood flow measured in vivo.

Exercise training enhances basic fibroblast growth factor-induced collateral blood flow

1998 ◽  
Vol 274 (6) ◽  
pp. H2053-H2061 ◽  
Author(s):  
H. T. Yang ◽  
Robert W. Ogilvie ◽  
Ronald L. Terjung
Keyword(s):  
Blood Flow ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Calf Muscle ◽  
Muscle Performance ◽  
Fibroblast Growth ◽  
Collateral Blood Flow ◽  
Collateral Vessel ◽  
Blood Flows

This study evaluated whether daily exercise would enhance the peripheral collateral vessel development found in response to exogenous basic fibroblast growth factor (bFGF) infusion. After bilateral femoral occlusion, male Sprague-Dawley rats (∼325 g) received intra-arterial infusions of either bFGF (1 μg/day; n = 15) or carrier solution ( n = 13) via osmotic pumps for 2 wk. Subgroups of each treatment were kept sedentary (cage activity) or trained by walking at 20 m/min at 15% grade, two times a day, 5 days/wk for 4 wk. Training markedly increased citrate synthase activity in the active muscle ( P < 0.001). Muscle function and blood flows (85Sr microsphere) were evaluated using an isolated hindquarter perfused at 100 mmHg via the abdominal aorta. The significant increase in blood flow to the entire hindlimb in the sedentary animals, caused by bFGF infusion ( P < 0.05), was further increased ( P < 0.01) in the bFGF-trained group. The quantitatively largest increases in blood flows were observed in the collateral-dependent tissues of the distal hindlimb. Blood flows to the entire calf muscle group increased ∼140% in carrier-trained ( P < 0.001), ∼180% in bFGF sedentary ( P< 0.001), and ∼240% in the bFGF-trained ( P < 0.001) groups compared with the carrier sedentary group. The increases in collateral blood flow were functionally important, as improvements in calf muscle performance correlated with measured blood flows. Our results demonstrate that exogenous bFGF administration in combination with a moderate-intensity exercise program greatly increases collateral-dependent blood flow and improves muscle performance. That physical activity enriched the bFGF response is consistent with the hypothesis that hemodynamic factors are important contributors to collateral vessel enlargement.

VEGF121- and bFGF-induced increase in collateral blood flow requires normal nitric oxide production

2001 ◽  
Vol 280 (3) ◽  
pp. H1097-H1104 ◽  
Author(s):  
H. T. Yang ◽  
Z. Yan ◽  
Judith A. Abraham ◽  
Ronald L. Terjung
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Growth Factors ◽  
Growth Factor ◽  
Vascular Remodeling ◽  
No Production ◽  
Collateral Blood Flow ◽  
Angiogenic Growth Factors ◽  
Blood Flows ◽  
Calf Muscles

The angiogenic proteins basic fibroblast growth factor (bFGF; FGF-2) and vascular endothelial growth factor 121 (VEGF121) are each able to enhance the collateral-dependent blood flow after bilateral femoral artery ligation in rats. To study the effect of nitric oxide (NO) synthase (NOS) inhibition on bFGF- or VEGF121-induced blood flow expansion, the femoral arteries of male Sprague-Dawley rats were ligated bilaterally, and the animals were given tap water [non- NG-nitro-l-arginine methyl ester (l-NAME) group; n = 36] or water that contained l-NAME (l-NAME group; 2 mg/ml, n = 36). Animals from each group were further divided into three subgroups: vehicle ( n = 12), bFGF (5 μg · kg−1· day−1, n = 12), or VEGF121(10 μg · kg−1· day−1, n = 12). Growth factors were delivered via intra-arterial infusion with osmotic pumps over days 1–14. On day 16, after a 2-day delay to permit clearance of bFGF and VEGF from the circulation, maximal collateral blood flow was determined by85Sr- and141Ce-labeled microspheres during treadmill running.l-NAME (∼137 mg · kg−1· day−1) for 18 days increased systemic blood pressure (∼26%, P < 0.001). In the absence of l-NAME, collateral-dependent blood flows to the calf muscles were greater in the VEGF121- and bFGF-treated subgroups (85 ± 4.5 and 80 ± 2.9 ml · min−1· 100 g−1, respectively) than in the vehicle subgroup (49 ± 3.0 ml · min−1· 100 g−1, P < 0.001). In the presence of NOS inhibition byl-NAME, blood flows to the calf muscles were essentially equivalent among the three subgroups (54 ± 3.0, 56 ± 5.1, and 47 ± 2.0 ml · min−1· 100 g−1in the bFGF-, VEGF121-, and vehicle-treated subgroups, respectively) and were not different from the blood flow in the non-l-NAME vehicle subgroup. Our results therefore indicate that normal NO production is essential for the enhanced vascular remodeling induced by exogenous bFGF or VEGF121in this rat model of experimental peripheral arterial insufficiency. These results imply that a blunted endothelial NO production could temper vascular remodeling in response to these angiogenic growth factors.

scholarly journals Jonckheere–Terpstra–Kendall-based non-parametric analysis of temporal differential gene expression

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hitoshi Iuchi ◽  
Michiaki Hamada
Keyword(s):  
Gene Expression ◽  
Time Series ◽  
Time Course ◽  
Time Series Data ◽  
Expression Patterns ◽  
Detection Methods ◽  
Series Data ◽  
Expression Levels ◽  
Over Time ◽  
Non Parametric

Abstract Time-course experiments using parallel sequencers have the potential to uncover gradual changes in cells over time that cannot be observed in a two-point comparison. An essential step in time-series data analysis is the identification of temporal differentially expressed genes (TEGs) under two conditions (e.g. control versus case). Model-based approaches, which are typical TEG detection methods, often set one parameter (e.g. degree or degree of freedom) for one dataset. This approach risks modeling of linearly increasing genes with higher-order functions, or fitting of cyclic gene expression with linear functions, thereby leading to false positives/negatives. Here, we present a Jonckheere–Terpstra–Kendall (JTK)-based non-parametric algorithm for TEG detection. Benchmarks, using simulation data, show that the JTK-based approach outperforms existing methods, especially in long time-series experiments. Additionally, application of JTK in the analysis of time-series RNA-seq data from seven tissue types, across developmental stages in mouse and rat, suggested that the wave pattern contributes to the TEG identification of JTK, not the difference in expression levels. This result suggests that JTK is a suitable algorithm when focusing on expression patterns over time rather than expression levels, such as comparisons between different species. These results show that JTK is an excellent candidate for TEG detection.

scholarly journals Lack of Obvious Influence of PLLA Nanofibers on the Gene Expression of BMP-2 and VEGF during Growth and Differentiation of Human Mesenchymal Stem Cells

2009 ◽  
Vol 9 ◽  
pp. 313-319 ◽  
Author(s):  
Markus D. Schofer ◽  
S. Fuchs-Winkelmann ◽  
C. Wack ◽  
M. Rudisile ◽  
R. Dersch ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Time Course ◽  
Negative Impact ◽  
Fracture Repair ◽  
Bone Morphogenetic Protein 2 ◽  
Vegf Gene ◽  
Down Regulation ◽  
Artificial Graft ◽  
The Impact

Growth factors like bone morphogenetic protein 2 (BMP-2) and vascular endothelial growth factor (VEGF) play an important role in bone remodeling and fracture repair. Therefore, with respect to tissue engineering, an artificial graft should have no negative impact on the expression of these factors. In this context, the aim of this study was to analyze the impact of poly(L-lactic acid) (PLLA) nanofibers on VEGF and BMP-2 gene expression during the time course of human mesenchymal stem cell (hMSC) differentiation towards osteoblasts. PLLA matrices were seeded with hMSCs and cultivated over a period of 22 days under growth and osteoinductive conditions, and analyzed during the course of culture, with respect to gene expression of VEGF and BMP-2. Furthermore, BMP-2–enwoven PLLA nanofibers were used in order to elucidate whether initial down-regulation of growth factor expression could be compensated. Although there was a great interpatient variability with respect to the expression of VEGF and BMP-2, PLLA nanofibers tend to result in a down-regulation in BMP-2 expression during the early phase of cultivation. This effect was diminished in the case of VEGF gene expression. The initial down-regulation was overcome when BMP-2 was directly incorporated into the PLLA nanofibers by electrospinning. Furthermore, the incorporation of BMP-2 into the PLLA nanofibers resulted in an increase in VEGF gene expression. Summarized, the results indicate that the PLLA nanofibers have little effect on growth factor production. An enhancement in gene expression of BMP-2 and VEGF can be achieved by an incorporation of BMP-2 into the PLLA nanofibers.

scholarly journals Growth factor–induced shedding of syndecan-1 confers glypican-1 dependence on mitogenic responses of cancer cells

2005 ◽  
Vol 171 (4) ◽  
pp. 729-738 ◽  
Author(s):  
Kan Ding ◽  
Martha Lopez-Burks ◽  
José Antonio Sánchez-Duran ◽  
Murray Korc ◽  
Arthur D. Lander
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Cell Surface ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Sulfate Proteoglycan ◽  
Matrix Metalloproteinase 7 ◽  
Over Time

The cell surface heparan sulfate proteoglycan (HSPG) glypican-1 is up-regulated by pancreatic and breast cancer cells, and its removal renders such cells insensitive to many growth factors. We sought to explain why the cell surface HSPG syndecan-1, which is also up-regulated by these cells and is a known growth factor coreceptor, does not compensate for glypican-1 loss. We show that the initial responses of these cells to the growth factor FGF2 are not glypican dependent, but they become so over time as FGF2 induces shedding of syndecan-1. Manipulations that retain syndecan-1 on the cell surface make long-term FGF2 responses glypican independent, whereas those that trigger syndecan-1 shedding make initial FGF2 responses glypican dependent. We further show that syndecan-1 shedding is mediated by matrix metalloproteinase-7 (MMP7), which, being anchored to cells by HSPGs, also causes its own release in a complex with syndecan-1 ectodomains. These results support a specific role for shed syndecan-1 or MMP7–syndecan-1 complexes in tumor progression and add to accumulating evidence that syndecans and glypicans have nonequivalent functions in vivo.

Abstract 249: Delayed Gene Transfer Increases Transgene Expression in Vein Grafts

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Liang Du ◽  
Jingwan Zhang ◽  
Alexander Clowes ◽  
David Dichek
Keyword(s):  
Gene Expression ◽  
Blood Flow ◽  
Gene Transfer ◽  
Transgene Expression ◽  
Ex Vivo ◽  
Arterial Blood Flow ◽  
Vein Grafts ◽  
Arterial Blood ◽  
En Face

Background Autogenous vein grafts are effective therapies for obstructive arterial disease. However, their long-term utility is limited by stenosis and occlusion. Genetic engineering of veins that prevents intimal hyperplasia and atherosclerosis could significantly improve the clinical utility of vein grafts. We recently reported that a helper-dependent adenoviral vector (HDAd) reduces atherosclerosis 4 wks after gene transfer in fat-fed rabbits and can express a therapeutic transgene (apo AI) in normal rabbit carotids for at least 48 wks. Use of HDAd for vein graft gene therapy will depend on achievement of similarly high and persistent transgene expression in grafted veins. Hypothesis We tested the hypothesis that Ad-mediated transgene expression in grafted veins (at an early time point) can be increased by varying the timing of gene transfer. Methods Rabbit external jugular veins were transduced by exposure to a beta galactosidase (b-gal)-expressing Ad: in situ either without (a) or with (b) immediate arterial grafting; c) ex vivo with grafting after overnight incubation with Ad; d) in vivo immediately after grafting and e) in vivo 4 wks after grafting (n = 6 - 19 veins/group). Transgene expression was measured in veins removed 3 d after Ad exposure by PCR quantitation of b-gal mRNA and by en-face planimetry of blue-stained area. Results B-gal transgene expression was higher in ungrafted veins than in veins grafted immediately after gene transfer (84 ± 17 vs 9.4 ± 2.0 arbitrary units (AU); P < 0.0001). Overnight incubation of veins with Ad increased gene expression ex vivo by 10-fold but neither this nor performing vector infusion immediately after grafting improved gene expression (11 ± 4.7 and 9.1 ± 1.8 AU; P > 0.9 for both vs immediately grafted veins). Delaying gene transfer until 4 wks after grafting significantly increased gene expression, to a level equivalent to transgene expression in ungrafted veins (61 ± 11 AU; P = 0.3 vs ungrafted veins). En face planimetry yielded similar results. Conclusions Exposure of a transduced vein to arterial blood flow is associated with significant loss of transgene expression. Transgene expression in grafted veins is significantly higher when gene transfer is performed 4 wks after exposure of the vein to arterial blood flow.

Fibroblast Growth Factor 23 (FGF23) leads to endolysosomal routing of the renal phosphate co-transporters NaPi-IIa and NaPi-IIc in vivo

2021 ◽  
Author(s):  
Catharina J Küng ◽  
Betül Haykir ◽  
Udo Schnitzbauer ◽  
Daniela Egli-Spichtig ◽  
Nati Hernando ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Time Course ◽  
Fibroblast Growth Factor 23 ◽  
Fibroblast Growth ◽  
Extracellular Signal ◽  
Early Endosomes ◽  
Lysosomal Proteases ◽  
Intracellular Pathway

The sodium-dependent phosphate co-transporters NaPi-IIa and NaPi-IIc located at the brush border membrane of renal proximal tubules are regulated by numerous factors, including fibroblast growth factor 23 (FGF23). FGF23 downregulates NaPi-IIa and NaPi-IIc abundance after activating a signaling pathway involving phosphorylation of the extracellular signal-regulated protein kinase (phospho-ERK1/2). FGF23 also downregulates the expression of renal 1-α-hydroxylase (Cyp27b1) and upregulates 24-hydroxylase (Cyp24a1), thus reducing plasma calcitriol levels. Here, we examined the time course of the FGF23-induced internalization of NaPi-IIa and NaPi-IIc and their intracellular pathway towards degradation in vivo. Mice were injected intraperitoneally with recombinant human FGF23 (rh-FGF23) in the absence (biochemical analysis) or presence (immunohistochemistry) of leupeptin, an inhibitor of lysosomal proteases. Phosphorylation of ERK1/2 was enhanced 60 minutes after rh-FGF23 administration, and increased phosphorylation was still detected 480 minutes post-injection. Co-localization of phospho-ERK1/2 with NaPi-IIa was seen at 60, 120 and partly at 480 minutes. The abundance of both co-transporters was reduced 240 minutes after rh-FGF23 administration, with a further reduction at 480 minutes. NaPi-IIa and NaPi-IIc were found to co-localize with clathrin and early endosomal antigen 1 (EEA1) as early as 120 minutes after rh-FGF23 injection. Both co-transporters partially co-localized with cathepsin B and Lamp1, markers of lysosomes, 120 minutes after rh-FGF23 injection. Thus, NaPi-IIa and NaPi-IIc are internalized within 2 hours upon rh-FGF23 injection. Both co-transporters share the pathway of clathrin-mediated endocytosis that leads first to early endosomes, finally resulting in trafficking towards the lysosome as early as 120 minutes after rh-FGF23 administration.

280 MULTILINEAGE POTENTIAL OF PORCINE BONE MARROW AND ADIPOSE-DERIVED MESENCHYMAL STEM CELLS IN 3-D ALGINATE HYDROGELS

2009 ◽  
Vol 21 (1) ◽  
pp. 237 ◽  
Author(s):  
D. Kim ◽  
A. J. Maki ◽  
H.-J. Kong ◽  
E. Monaco ◽  
M. Bionaz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tissue Engineering ◽  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Adipogenic Differentiation ◽  
Cell Types ◽  
Scaffold Material ◽  
Over Time

Adipose tissue presents an appealing alternative to bone marrow as a source of mesenchymal stem cells (MSC). However, in order to enhance cell proliferation and differentiation, 3-dimensional (3-D) culture may be required. A 3-D culture has benefits due to its more in vivo-like environment. Further, to form a functional tissue, a scaffold material is required to ensure proper shape and allow for efficient delivery of nutrients and growth factors. Alginate, a resorbable hydrogel, is a potential injectable scaffold for fat and bone tissue engineering due to its high biocompatibility, gelation with calcium and slow dissolution in a physiologic environment. In the present study, we examined the viability, gene expression and morphology of MSC, isolated from porcine adipose (ADSC) and bone marrow (BMSC), during osteogenic and adipogenic differentiation in a 3D alginate hydrogel environment for 0, 7 and 14 days (d). ADSC and BMSC were infused into alginate hydrogels, which polymerized upon the addition of Ca+2 ions. Both stem cell types were differentiated into osteoblasts using 0.1 μm dexamethasone, 10 mm beta glycerophosphate and 50 μm ascorbic acid, whereas adipocytes were differentiated using 10 μm insulin, 1 μm dexamethasone, and 0.5 mm IBMX. Osteogenic differentiation was confirmed using alkaline phosphatase, Von Kossa, and alizarin red S staining and adipogenic differentiation was confirmed using Oil Red O. Cell viability and proliferation was quantified using the MTT assay. Gene expression was measured using qPCR. The morphology of ADSC and BMSC differentiated toward osteogenic lineages changed with both cell types forming osteogenic nodules over time. The nodules formed by ADSC were larger in diameter than those formed by BMSC. Unlike the osteogenic cells that formed nodules, the ADSC and BMSC differentiated into adipogenic cells showed no significant changes in cell size or aggregation. Gene expression results indicated increased PPARG expression in BMSC with time whereas ADSC showed a peak of expression on day 7 and then decreased. ADSC showed increased (14-fold) PPRG expression when compared with BMSC. ADSC had 160-fold less expression of ALP than BMSC. BMSC showed a 16-fold higher expression level of BGLAP than ADSC. ADSC showed a 15.8% higher expression than BMSC for COL1a1. Both ADSC and BMSC showed similar trends SPARC expression, but BMSC had a 12-fold higher expression of SPP1 than ADSC. In summary, both types of mesenchymal stem cells successfully differentiated into both lineages and maintained viability in the hydrogel over time. In conclusion, alginate is a viable scaffold material for the differentiation of mesenchymal stem cells for tissue engineering applications. These results allow for future studies using the pig as an in vivo fat and bone tissue engineering model. This research was supported by the Illinois Regenerative Medicine Institute.

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