| 1. |
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| 2. |
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| 3. |
- Becirovic-Agic, Mediha, et al.
(författare)
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Time course of decompensation after angiotensin II and high-salt diet in Balb/CJ mice suggests pulmonary hypertension-induced cardiorenal syndrome
- 2019
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Ingår i: American Journal of Physiology. Regulatory Integrative and Comparative Physiology. - : the American Physiological Society. - 0363-6119 .- 1522-1490. ; 316:5, s. R563-R570
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Tidskriftsartikel (refereegranskat)abstract
- The genetic background of a mouse strain determines its susceptibility to disease. C57BL/6J and Balb/CJ are two widely used inbred mouse strains that we found react dramatically differently to angiotensin II and high-salt diet (ANG II + Salt). Balb/CJ show increased mortality associated with anuria and edema formation while C57BL/6J develop arterial hypertension but do not decompensate and die. Clinical symptoms of heart failure in Balb/CJ mice gave the hypothesis that ANG II + Salt impairs cardiac function and induces cardiac remodeling in male Balb/CJ but not in male C57BL/6J mice. To test this hypothesis, we measured cardiac function using echocardiography before treatment and every day for 7 days during treatment with ANG II + Salt. Interestingly, pulsed wave Doppler of pulmonary artery flow indicated increased pulmonary vascular resistance and right ventricle systolic pressure in Balb/CJ mice, already 24 h after ANG II + Salt treatment was started. In addition, Balb/CJ mice showed abnormal diastolic filling indicated by reduced early and late filling and increased isovolumic relaxation time. Furthermore, Balb/CJ exhibited lower cardiac output compared with C57BL/6J even though they retained more sodium and water, as assessed using metabolic cages. Left posterior wall thickness increased during ANG II + Salt treatment but did not differ between the strains. In conclusion, ANG II + Salt treatment causes early restriction of pulmonary flow and reduced left ventricular filling and cardiac output in Balb/CJ, which results in fluid retention and peripheral edema. This makes Balb/CJ a potential model to study the adaptive capacity of the heart for identifying new disease mechanisms and drug targets.
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| 4. |
- Jönsson, Sofia, et al.
(författare)
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Angiotensin II and salt-induced decompensation in Balb/CJ mice is aggravated by fluid retention related to low oxidative stress
- 2019
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Ingår i: American Journal of Physiology - Renal Physiology. - : American Physiological Society. - 1931-857X .- 1522-1466. ; 316:5, s. F914-F933
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Tidskriftsartikel (refereegranskat)abstract
- Balb/CJ mice are more sensitive to treatment with angiotensin II (ANG II) and high-salt diet compared with C57BL/6J mice. Together with higher mortality, they develop edema, signs of heart failure, and acute kidney injury. The aim of the present study was to identify differences in renal gene regulation that may affect kidney function and fluid balance, which could contribute to decompensation in Balb/CJ mice after ANG II + salt treatment. Male Balb/CJ and C57BL/6J mice were divided into the following five different treatment groups: control, ANG II, salt, ANG II + salt. and ANG II + salt + N-acetylcysteine. Gene expression microarrays were used to explore differential gene expression after treatment and between the strains. Published data from the Mouse Genome Database were used to identify the associated genomic differences. The glomerular filtration rate (GFR) was measured using inulin clearance, and fluid balance was measured using metabolic cages. Gene ontology enrichment analysis of gene expression microarrays identified glutathione transferase (antioxidant system) as highly enriched among differentially expressed genes. Balb/CJ mice had similar GFR compared with C57BL/6J mice but excreted less Na+ and water, although net fluid and electrolyte balance did not differ, suggesting that Balb/CJ mice may be inherently more prone to decompensation. Interestingly, C57BL/6J mice had higher urinary oxidative stress despite their relative protection from decompensation. In addition, treatment with the antioxidant N-acetylcysteine decreased oxidative stress in C57BL/6J mice, reduced urine excretion, and increased mortality. Balb/CJ mice are more sensitive than C57BL/6J to ANG II + salt, in part mediated by lower oxidative stress, which favors fluid and Na+ retention.
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| 5. |
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| 6. |
- Tveitarås, Maria K, et al.
(författare)
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Matrix Metalloproteinase-2 Knockout and Heterozygote Mice Are Protected from Hydronephrosis and Kidney Fibrosis after Unilateral Ureteral Obstruction
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Matrix Metalloproteinase-2 (Mmp2) is a collagenase known to be important in the development of renal fibrosis. In unilateral ureteral obstruction (UUO) the obstructed kidney (OK) develops fibrosis, while the contralateral (CL) does not. In this study we investigated the effect of UUO on gene expression, fibrosis and pelvic remodeling in the kidneys of Mmp2 deficient mice (Mmp2-/-), heterozygous animals (Mmp2+/-) and wild-type mice (Mmp2+/+). Sham operated animals served as controls (Cntrl). UUO was prepared under isoflurane anaesthesia, and the animals were sacrificed after one week. UUO caused hydronephrosis, dilation of renal tubules, loss of parenchymal thickness, and fibrosis. Damage was most severe in Mmp2+/+ mice, while both Mmp2-/- and Mmp2+/- groups showed considerably milder hydronephrosis, no tubular necrosis, and less tubular dilation. Picrosirius red quantification of fibrous collagen showed 1.63±0.25% positivity in OK and 0.29±0.11% in CL (p<0.05) of Mmp2+/+, Mmp2-/- OK and Mmp2-/- CL exhibited only 0.49±0.09% and 0.23±0.04% (p<0.05) positivity, respectively. Mmp2+/- OK and Mmp2+/- CL showed 0.43±0.09% and 0.22±0.06% (p<0.05) positivity, respectively. Transcriptomic analysis showed that 26 genes (out of 48 examined) were differentially expressed by ANOVA (p<0.05). 25 genes were upregulated in Mmp2+/+ OK compared to Mmp2+/+ CL: Adamts1, -2, Col1a1, -2, -3a1, -4a1, -5a1, -5a2, Dcn, Fbln1, -5, Fmod, Fn1, Itga2, Loxl1, Mgp, Mmp2, -3, Nid1, Pdgfb, Spp1, Tgfb1, Timp2, Trf, Vim. In Mmp2-/- and Mmp2+/- 18 and 12 genes were expressed differentially between OK and CL, respectively. Only Mmp2 was differentially regulated when comparing Mmp2-/- OK and Mmp2+/- OK. Under stress, it appears that Mmp2+/- OK responds with less Mmp2 upregulation than Mmp2+/+ OK, suggesting that there is a threshold level of Mmp2 necessary for damage and fibrosis to occur. In conclusion, reduced Mmp2 expression during UUO protects mice against hydronephrosis and renal fibrosis.
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| 7. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 8. |
- Arteaga-Marrero, Natalia, et al.
(författare)
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Radiation treatment monitoring using multimodal functional imaging: PET/CT ((18)F-Fluoromisonidazole & (18)F-Fluorocholine) and DCE-US.
- 2015
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Ingår i: Journal of Translational Medicine. - : Springer Science and Business Media LLC. - 1479-5876. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- This study aims to assess the effect of radiation treatment on the tumour vasculature and its downstream effects on hypoxia and choline metabolism using a multimodal approach in the murine prostate tumour model CWR22. Functional parameters derived from Positron Emission Tomography (PET)/Computer Tomography (CT) with (18)F-Fluoromisonidazole ((18)F-FMISO) and (18)F-Fluorocholine ((18)F-FCH) as well as Dynamic Contrast-Enhanced Ultrasound (DCE-US) were employed to determine the relationship between metabolic parameters and microvascular parameters that reflect the tumour microenvironment. Immunohistochemical analysis was employed for validation.
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| 9. |
- Arteaga-Marrero, Natalia, et al.
(författare)
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Radiation treatment monitoring with DCE-US in CWR22 prostate tumor xenografts
- 2019
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Ingår i: Acta Radiologica. - : Sage Publications. - 0284-1851 .- 1600-0455. ; 60:6, s. 788-797
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Tidskriftsartikel (refereegranskat)abstract
- Background: Longitudinal monitoring of potential radiotherapy treatment effects can be determined by dynamic contrast-enhanced ultrasound (DCE-US).Purpose: To assess functional parameters by means of DCE-US in a murine subcutaneous model of human prostate cancer, and their relationship to dose deposition and time-frame after treatment. A special focus has been placed to evaluate the vascular heterogeneity of the tumor and on the most suitable data analysis approach that reflects this heterogeneity.Material and Methods: In vivo DCE-US was acquired 24 h and 48 h after radiation treatment with a single dose of 7.5 Gy and 10 Gy, respectively. Tumor vasculature was characterized pixelwise using the Brix pharmacokinetic analysis of the time-intensity curves.Results: Longitudinal changes were detected (P < 0.001) at 24 h and 48 h after treatment. At 48 h, the eliminating rate constant of the contrast agent from the plasma, kel, was correlated (P ≤ 0.05) positively with microvessel density (MVD; rτ = 0.7) and negatively with necrosis (rτ = –0.6) for the treated group. Furthermore, Akep, a parameter related to transcapillary transport properties, was also correlated to MVD (rτ = 0.6, P ≤ 0.05).Conclusion: DCE-US has been shown to detect vascular changes at a very early stage after radiotherapy, which is a great advantage since DCE-US is non-invasive, available at most hospitals, and is low in cost compared to other techniques used in clinical practice.
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| 10. |
- Burmakin, Mikhail, et al.
(författare)
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Imatinib increases oxygen delivery in extracellular matrix-rich but not in matrix-poor experimental carcinoma
- 2017
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Ingår i: Journal of Translational Medicine. - : BioMed Central. - 1479-5876. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Imatinib causes increased turnover of stromal collagen, reduces collagen fibril diameter, enhances extracellular fluid turnover and lowers interstitial fluid pressure (IFP) in the human colonic carcinoma KAT-4/HT-29 (KAT-4) xenograft model. Methods: We compared the effects of imatinib on oxygen levels, vascular morphology and IFP in three experimental tumor models differing in their content of a collagenous extracellular matrix. Results: Neither the KAT4 and CT-26 colonic carcinoma models, nor B16BB melanoma expressed PDGF beta-receptors in the malignant cells. KAT-4 tumors exhibited a well-developed ECM in contrast to the other two model systems. The collagen content was substantially higher in KAT-4 than in CT-26, while collagen was not detectable in B16BB tumors. The pO(2) was on average 5.4, 13.9 and 19.3 mmHg in KAT-4, CT-26 and B16BB tumors, respectively. Treatment with imatinib resulted in similar pO(2)-levels in all three tumor models but only in KAT-4 tumors did the increase reach statistical significance. It is likely that after imatinib treatment the increase in pO(2) in KAT-4 tumors is caused by increased blood flow due to reduced vascular resistance. This notion is supported by the significant reduction observed in IFP in KAT-4 tumors after imatinib treatment. Vessel area varied between 4.5 and 7% in the three tumor models and was not affected by imatinib treatment. Imatinib had no effect on the fraction of proliferating cells, whereas the fraction of apoptotic cells increased to a similar degree in all three tumor models. Conclusion: Our data suggest that the effects of imatinib on pO(2)-levels depend on a well-developed ECM and provide further support to the suggestion that imatinib acts by causing interstitial stroma cells to produce a less dense ECM, which would in turn allow for an increased blood flow. The potential of imatinib treatment to render solid tumors more accessible to conventional treatments would therefore depend on the degree of tumor desmoplasia.
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| 11. |
- Friman, Tomas, et al.
(författare)
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Increased Fibrosis and Interstitial Fluid Pressure in Two Different Types of Syngeneic Murine Carcinoma Grown in Integrin β3-Subunit Deficient Mice
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3, s. e34082-
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Tidskriftsartikel (refereegranskat)abstract
- Stroma properties affect carcinoma physiology and direct malignant cell development. Here we present data showing that alpha(V)beta(3) expressed by stromal cells is involved in the control of interstitial fluid pressure (IFP), extracellular volume (ECV) and collagen scaffold architecture in experimental murine carcinoma. IFP was elevated and ECV lowered in syngeneic CT26 colon and LM3 mammary carcinomas grown in integrin beta(3)-deficient compared to wild-type BALB/ c mice. Integrin beta(3)-deficiency had no effect on carcinoma growth rate or on vascular morphology and function. Analyses by electron microscopy of carcinomas from integrin beta(3)-deficient mice revealed a coarser and denser collagen network compared to carcinomas in wild-type littermates. Collagen fibers were built from heterogeneous and thicker collagen fibrils in carcinomas from integrin beta(3)-deficient mice. The fibrotic extracellular matrix (ECM) did not correlate with increased macrophage infiltration in integrin beta(3)-deficient mice bearing CT26 tumors, indicating that the fibrotic phenotype was not mediated by increased inflammation. In conclusion, we report that integrin beta(3)-deficiency in tumor stroma led to an elevated IFP and lowered ECV that correlated with a more fibrotic ECM, underlining the role of the collagen network for carcinoma physiology.
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| 12. |
- Heuchel, Rainer, et al.
(författare)
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Platelet-derived growth factor beta receptor regulates interstitial fluid homeostasis through phosphatidylinositol-3' kinase signaling
- 1999
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Ingår i: Proc Natl Acad Sci U S A. ; 96:20, s. 11410-5
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) isoforms lead to mitogenic, survival, and chemotactic responses in a variety of mesenchymal cell types during development and in the adult. We have studied the importance of phosphatidylinositol-3' kinase (PI3K) signaling in these responses by mutating the PI3K-binding sites in the PDGF-beta receptor by gene targeting in embryonic stem cells. Homozygous mutant mice developed normally; however, cells derived from the mutants were less chemotactic and had largely lost their ability to contract collagen gels in response to PDGF. Injection of a mast cell degranulating agent in mice led to a decrease in interstitial fluid pressure resulting in edema formation. In contrast to wild-type mice, mutant mice were unable to normalize the pressure after treatment with PDGF. Taken together, these observations suggest a function for PDGF signaling through PI3K in interstitial fluid homeostasis by modulating the tension between cells and extracellular matrix structures.
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| 13. |
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| 14. |
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| 15. |
- Kłosowska-Wardega, Agnieszka, et al.
(författare)
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Combined anti-angiogenic therapy targeting PDGF and VEGF receptors lowers the interstitial fluid pressure in a murine experimental carcinoma
- 2009
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:12, s. e8149-
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Tidskriftsartikel (refereegranskat)abstract
- Elevation of the interstitial fluid pressure (IFP) of carcinoma is an obstacle in treatment of tumors by chemotherapy and correlates with poor drug uptake. Previous studies have shown that treatment with inhibitors of platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF) signaling lowers the IFP of tumors and improve chemotherapy. In this study, we investigated whether the combination of PDGFR and VEGFR inhibitors could further reduce the IFP of KAT-4 human carcinoma tumors. The tumor IFP was measured using the wick-in-needle technique. The combination of STI571 and PTK/ZK gave an additive effect on the lowering of the IFP of KAT-4 tumors, but the timing of the treatment was crucial. The lowering of IFP following combination therapy was accompanied by vascular remodeling and decreased vascular leakiness. The effects of the inhibitors on the therapeutic efficiency of Taxol were investigated. Whereas the anti-PDGF and anti-VEGF treatment did not significantly inhibit tumor growth, the inhibitors enhanced the effect of chemotherapy. Despite having an additive effect in decreasing tumor IFP, the combination therapy did not further enhance the effect of chemotherapy. Simultaneous targeting of VEGFR and PDGFR kinase activity may be a useful strategy to decrease tumor IFP, but the timing of the inhibitors should be carefully determined.
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| 16. |
- Lidén, Åsa, et al.
(författare)
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A secreted collagen- and fibronectin-binding streptococcal protein modulates cell-mediated collagen gel contraction and interstitial fluid pressure
- 2008
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 283:3, s. 1234-1242
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Tidskriftsartikel (refereegranskat)abstract
- Fibroblast-mediated collagen gel contraction depends on collagen-binding beta1 integrins. Perturbation of these integrins reveals an alternative contraction process that is integrin alphaVbeta3-dependent and platelet-derived growth factor (PDGF) BB-stimulated. Connective tissue cells actively control interstitial fluid pressure (IFP), and inflammation-induced lowering of IFP provides a driving force for edema formation. PDGF-BB normalizes a lowered IFP by an alphaVbeta3-dependent process. A potential modulation of IFP by extracellular matrix-binding bacterial proteins has previously not been addressed. The fibronectin (FN)-binding protein FNE is specifically secreted by the highly virulent Streptococcus equi subspecies equi. FNE bound FN and native collagen type I with K(d) values of approximately 20 and approximately 50 nm determined by solid-phase binding assays. Rotary shadowing revealed a single FNE binding site located at on average 122 nm from the C terminus of procollagen type I. FNE induced alphaVbeta3-mediated contraction by C2C12 cells in a concentration-dependent manner having a maximal effect at approximately 100 nm. This activity of FNE required cellular FN, and FNE acted synergistically to added plasma FN or PDGF-BB. FNE enhanced binding of soluble FN to immobilized collagen, and conversely the binding of collagen to immobilized FN. Marked bell-shaped concentration dependences for these interactions suggest that FNE forms a bridge between FN and collagen. Finally, FNE normalized dermal IFP lowered by anaphylaxis. Our data suggest that secreted FNE normalized lowering of IFP by stimulating connective tissue cell contraction.
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| 17. |
- Liden, Åsa, et al.
(författare)
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Integrin αVβ3 can substitute for collagen‐binding β1‐integrins in vivo to maintain a homeostatic interstitial fluid pressure
- 2018
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Ingår i: Experimental Physiology. - 0958-0670 .- 1469-445X. ; 103:5, s. 629-634
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Tidskriftsartikel (refereegranskat)abstract
- Accumulated data indicate that cell‐mediated contraction of reconstituted collagenous gels in vitro can serve as a model for cell‐mediated control of interstitial fluid pressure (PIF) in vivo. A central role for collagen‐binding β1‐integrins in both processes has been established. Furthermore, integrin αVβ3 takes over the role of collagen‐binding β1‐integrins in mediating contraction after perturbations of collagen‐binding β1‐integrins in vitro. Integrin αVβ3 is also instrumental for normalization of dermal PIF that has been lowered due to mast cell degranulation with compound 48/80 (C48/80) in vivo. Here we demonstrate a role of integrin αVβ3 in maintaining a long term homeostatic dermal PIF in mice lacking the collagen‐binding integrin α11β1 (α11−/− mice). Measurements of PIF were performed after circulatory arrest. Furthermore, cell‐mediated integrin αVβ3‐directed contraction of collagenous gels in vitro depends on free access to a collagen site known to bind several extracellular matrix (ECM) proteins that form substrates for αVβ3‐directed cell attachment, such as fibronectin and fibrin. A streptococcal collagen‐binding protein, CNE, specifically binds to and blocks this site on the collagen triple helix. Here we show that whereas CNE perturbed αVβ3‐directed and platelet‐derived growth factor BB‐induced normalization of dermal PIF after C48/80, it did not affect αVβ3‐dependent maintenance of a homeostatic dermal PIF. These data imply that dynamic modification of the ECM structure is needed during acute patho‐physiological modulations of PIF but not for long‐term maintenance of a homeostatic PIF. Our data thus show that collagen‐binding β1‐integrins, integrin αVβ3 and ECM structure are potential targets for novel therapy aimed at modulating oedema formation and hypovolemic shock during anaphylaxis.
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| 18. |
- Lidén, Åsa, et al.
(författare)
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Platelet-derived growth factor BB-mediated normalization of dermal interstitial fluid pressure after mast cell degranulation depends on beta3 but not beta1 integrins
- 2006
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Ingår i: Circulation Research. - 0009-7330 .- 1524-4571. ; 98:5, s. 635-641
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Tidskriftsartikel (refereegranskat)abstract
- Interstitial fluid pressure (PIF) is one of the determinants of transcapillary fluid flux and thereby interstitial fluid volume. Cell-mediated control of PIF regulates fluid content in the loose interstitial connective tissues that surround the capillary bed. To maintain a normal PIF in dermis, β1 integrins mediate the tensile strength applied by connective tissue cells on the extracellular matrix. Platelet-derived growth factor (PDGF)-BB normalizes anaphylaxis-induced reduction of PIF. Anti–β3 integrin IgG and a cyclic RGD peptide that inhibits the αVβ3 integrin blocked the ability of PDGF-BB to normalize the lowered PIF resulting from mast cell degranulation. PDGF-BB was unable to normalize PIF lowered as a result of mast cell degranulation in β3-negative mice. Monoclonal anti–β3 integrin IgG had no effect on PIF in normal mouse dermis. In contrast, administration of anti–β1 integrin IgM lowered PIF in normal dermis but had no effect on PDGF-BB–induced normalization of PIF after anaphylaxis. Furthermore, collagen gel contraction mediated by wild-type mouse embryonal fibroblasts were only marginally affected by function-blocking anti–β1 integrin antibodies, especially in the presence of PDGF-BB. In contrast, contraction mediated by αV-negative mouse embryonic fibroblasts was completely blocked by anti–β1 integrin antibodies, even after stimulation with PDGF-BB. These results show a previously unrecognized in vivo function for the αVβ3 integrin, as a participant in the control of PIF during inflammatory reactions. Furthermore, our data demonstrate that PDGF-BB induces connective tissue cells to generate tensile forces via αVβ3 during such reactions.
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| 19. |
- Pietras, Kristian, et al.
(författare)
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Inhibition of platelet-derived growth factor receptors reduces interstitial hypertension and increases transcapillary transport in tumors.
- 2001
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Ingår i: Cancer Res. - : American Association for Cancer Research. ; 61:7, s. 2929-2934
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Tidskriftsartikel (refereegranskat)abstract
- Most solid malignancies display interstitial hypertension and a poor uptake of anticancer drugs. Platelet-derived growth factor (PDGF) and the cognate tyrosine kinase receptors are expressed in many tumors. Signaling through PDGFbeta receptors was shown recently to increase interstitial fluid pressure (IFP) in dermis after anaphylaxis-induced lowering of IFP. In this study, we show that treatment with the selective PDGF receptor kinase inhibitor, STI571, formerly known as CGP57148B, decreased the interstitial hypertension and increased capillary-to-interstitium transport of 51Cr-EDTA in s.c. growing rat PROb colonic carcinomas. Furthermore, treatment with an antagonistic PDGF-B oligonucleotide aptamer decreased interstitial hypertension in these tumors. PDGFbeta receptors were expressed in blood vessels and stromal cells but not in the tumor cells of PROb colonic carcinomas. Our study indicates a previously unrecognized role of PDGF receptors in tumor biology, although similar effects of PDGF on IFP have been demonstrated previously in the dermis. The data suggest interference with PDGF receptors, or their ligands, as a novel strategy to increase drug uptake and therapeutic effectiveness of cancer chemotherapy.
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| 20. |
- Reed, Rolf K., et al.
(författare)
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Edema and fluid dynamics in connective tissue remodelling
- 2010
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Ingår i: Journal of Molecular and Cellular Cardiology. - : Elsevier BV. - 0022-2828 .- 1095-8584. ; 48:3, s. 518-523
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Forskningsöversikt (refereegranskat)abstract
- The review describes the role of loose connective tissues with focus on transcapillary exchange and edema formation with relevance for inflammation, fibrosis and tumors. Based on studies in these tissues, comparisons are made to the fibrotic processes in the heart.
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| 21. |
- Reed, Rolf K., et al.
(författare)
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Transcapillary exchange : role and importance of the interstitial fluid pressure and the extracellular matrix
- 2010
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Ingår i: Cardiovascular Research. - : Oxford University Press (OUP). - 0008-6363 .- 1755-3245. ; 87:2, s. 211-217
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Forskningsöversikt (refereegranskat)abstract
- This review will summarize current knowledge on the role of the extracellular matrix (ECM) in general and on the interstitial fluid pressure (P-if) in particular with regard to their importance in transcapillary exchange. The fluid volume in the interstitial space is normally regulated within narrow limits by automatic re-adjustment of the interstitial hydrostatic and colloid osmotic pressures in response to perturbations in capillary filtration and by the lymphatics. Contrary to this commonly accepted view, P-if can become an active force and create a fluid flux across the capillaries in several inflammatory reactions and trauma situations rather than limit the changes occurring. The molecular mechanisms involved in the lowering of P-if include the release of cellular tension exerted on the collagen and microfibril networks in the connective tissue via the collagen-binding beta(1)-integrins, thereby allowing the glycosaminoglycan ground substance, which is normally underhydrated, to expand and take up fluid. Several growth factors and cytokines, including the platelet-derived growth factor BB, are able to reverse a lowering of P-if and restore the normal compaction of the ECM. The magnitude of the lowering of P-if varies with the inflammatory response. In several inflammatory reactions, a lowering of P-if to -5 to -10 mmHg is seen, which will increase capillary filtration by 10-20 times since the normal capillary filtration pressure is usually 0.5-1 mmHg (skin and skeletal muscle). Unless this lowering of P-if is taken into account, the enhanced solute flux resulting from an inflammatory response will be ascribed to an increased capillary permeability.
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| 22. |
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| 23. |
- Salnikov, Alexei, et al.
(författare)
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Inhibition of carcinoma cell-derived VEGF reduces inflammatory characteristics in xenograft carcinoma
- 2006
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 119:12, s. 2795-2802
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Tidskriftsartikel (refereegranskat)abstract
- The stroma of carcinomas shares several characteristics with inflamed tissues including a distorted vasculature, active angiogenesis and macrophage infiltration. In addition, the tumor interstitial fluid pressure (P-IF) of the stroma is pathologically elevated. We show here that bevacizumab [rhuMab vascular endothelial growth factor (VEGF), Avastin], a monoclonal antibody to VEGF, at a dose of 5 mg/kg modulated inflammation in KAT-4 xenograft human anaplastic thyroid carcinoma tissue. At this dose, bevacizumab reduced the density of macrophages, MHC class II antigen expression by macrophages and II-1 beta mRNA expression. Furthermore, bevacizumab lowered tumor extracellular fluid volume, plasma protein leakage from tumor vessels, the number of CD31positive structures and tumor P-IF. The tumor plasma volume and the number of alpha-smooth muscle actin-positive vessels, however, remained unchanged. Our data suggest that carcinoma cellderived VEGF either directly or indirectly participates in maintaining an inflammatory microenvironment in experimental KAT4 carcinoma. Furthermore, our data indicate that the reduction of inflammation resulting in reduced vascular permeability and decrease in the tumor extracellular fluid volume by bevacizurnab contributes to reduced tumor P-IF.
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| 24. |
- Skogstrand, Trude, et al.
(författare)
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Arterial damage precedes the development of interstitial damage in the nonclipped kidney of two-kidney, one-clip hypertensive rats
- 2013
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Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 31:1, s. 152-159
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Tidskriftsartikel (refereegranskat)abstract
- Background: The progression of damage in the renal cortex has not been investigated in the nonclipped kidney of the two-kidney, one-clip model of renal hypertension. In other hypertensive models, damage has been found to progress from the juxtamedullary cortex (JMC) and outward, which has been attributed to early vascular effects. Method: The present study investigated the relation between perivascular deposition of collagen and structural damage after 16 and 24 weeks of hypertension in the nonclipped kidney in rats. Results: Periarterial collagen density in the kidney was significantly increased already 16 weeks after clipping, at that time tubulointerstitial damage was not evident. After 24 weeks of clipping, periarterial collagen was further increased, and tubulointerstitial damage had developed in the JMC, whereas the outer cortex was protected. Interstitial collagen was not significantly increased in any cortex part during the course of the experiment. Collagen type I a1 mRNA was increased in the JMC after 24 weeks, and alpha smooth muscle actin histochemistry and collagen type I a2 in-situ hybridization identified myofibroblasts around the arteries after 16 and 24 weeks as the major source of this increase. Conclusion: Fibrosis in the nonclipped kidney of renal hypertensive rats starts around the juxtamedullary resistance vessels and then progresses in the JMC, whereas the outer cortex is protected. This suggests that pressure-induced injury to the vasculature attracts or activates fibroblasts in the perivascular area, which may allow damage to progress by impairing vessel function.
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| 25. |
- Stuhr, L. E. B., et al.
(författare)
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High-dose, short-term, anti-inflammatory treatment with dexamethasone reduces growth and augments the effects of 5-fluorouracil on dimethyl-alpha- benzanthracene-induced mammary tumors in rats
- 2006
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 66:6, s. 477-486
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To evaluate the effects of dexamethasone (DXM) alone or in combination with 5-fluorouracil (5-FU) on dimethyl-alpha-benzanthracene (DMBA)-induced mammary tumors in rats. Material and methods. Female Sprague-Dawley rats were divided into 4 groups receiving: 1) saline (controls), 2) DXM (3 mg/kg), 3) 5-FU (1.5 mg/kg) and 4) DXM and 5-FU combined. The drugs were given i.p. every day for 4 days. Interstitial fluid pressure (Pif) and tumor growth were determined in all tumors on days 1, 5 and 7 using the "wick-in-the needle'' technique and by external size measurements, respectively. Vessel density and inflammatory cell infiltration of tumor tissue were analyzed by immunohistochemistry. Results. DXM treatment significantly retarded tumor growth and reduced Pif. Treatment with a combination of DXM and 5-FU reduced tumor size significantly more than any of the agents alone (p < 0.01 - 0.001). Enhanced uptake of 5-FU by DXM treatment was demonstrated by microdialysis. There were no differences in the density of CD31-positive vessels after DXM or 5-FU treatment, but inflammatory cell infiltration of tumor tissue was significantly reduced after DXM treatment. Conclusions. Our data suggest that DXM may be beneficial as an adjuvant to chemotherapy in the treatment of mammary cancer by increasing the uptake of 5-FU in the tumor.
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| 26. |
- Stuhr, Linda E. B., et al.
(författare)
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Peritumoral TNF alpha administration influences tumour stroma structure and physiology independently of growth in DMBA-induced mammary tumours
- 2008
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 68:7, s. 602-611
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Tidskriftsartikel (refereegranskat)abstract
- Background. Systemic treatment of malignancies with high doses of tumour necrosis factor-alpha (TNF alpha) has an anticancer effect, but also serious side effects. The aim of the present study was to elucidate the effects of local TNF alpha administration alone or in combination with chemotherapy on tumour stroma structure and physiology in di-methyl-benz-anthracene (DMBA)-induced mammary carcinomas in rats. Methods. TNF alpha (500 ng/mL in a volume of 5 mu L) was given s.c. around the carcinoma and 5-fluorouracil (5-FU) (1.5 mg/kg, volume of 0.2 mL) was given i.p on days 1, 4, 7 and 10. Results. Treatment with TNF alpha resulted in a significant reduction of tumour interstitial fluid pressure (TIFP: 75-87 %, p<0.02-0.001), as well as in the number of tumour-infiltrating macrophages, extracellular volume (ECV) and collagen fibril density in carcinoma. In addition, pH was lowered in tumours treated with TNF alpha, suggesting decreased aerobic metabolism. Treatment with TNF alpha, however, had no effect on tumour growth, arterial blood pressure, tumour vessel density, plasma volume or body weight. Concentrations of locally produced VEGF and IL-1 beta in carcinoma interstitial fluid or in serum were not affected by TNF alpha. The study demonstrated that these cytokines are produced locally in the tumour. Furthermore, TNF alpha had no effect on efficacy of treatment with 5-FU. Conclusions: Locally administered TNF alpha did not affect DMBA-induced mammary tumour growth or vasculature, but reduced inflammation and ECM structure, suggesting the latter to be of importance in the observed reduction in TIFP.
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| 27. |
- Svendsen, Oyvind Sverre, et al.
(författare)
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Integrin alphavbeta3 acts downstream of insulin in normalization of interstitial fluid pressure in sepsis and in cell-mediated collagen gel contraction
- 2008
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Ingår i: American Journal of Physiology. Heart and Circulatory Physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 295:2, s. H555-60
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Tidskriftsartikel (refereegranskat)abstract
- The administration of insulin is recommended to patients with severe sepsis and hyperglycemia. Previously, we demonstrated that insulin may have direct anti-inflammatory properties and counteracted fluid losses from the circulation by normalizing the interstitial fluid pressure (P(IF)). P(IF) is one of the Starling forces determining fluid flux over the capillary wall, and a lowered P(IF) is one of the driving forces in early edema formation in inflammatory reactions. Here we demonstrate that insulin restores a lipopolysaccharide (LPS)-lowered P(IF) via a mechanism involving integrin alpha(v)beta(3). In C57 black mice (n = 6), LPS lowered P(IF) from -0.2 +/- 0.2 to -1.6 +/- 0.3 (P < 0.05) and after insulin averaged -0.8 +/- 0.2 mmHg (P = 0.098 compared with after LPS). Corresponding values in wild-type BALB/c mice (n = 5) were -0.8 +/- 0.1, -2.1 +/- 0.3 (P < 0.05), and -0.8 +/- 0.3 mmHg (P < 0.05 compared with LPS) after insulin administration. In BALB/c integrin beta(3)-deficient (beta(3)(-/-)) mice (n = 6), LPS lowered P(IF) from -0.1 +/- 0.2 to -1.5 +/- 0.3 mmHg (P < 0.05). Insulin did not, however, restore P(IF) in these mice (averaged -1.7 +/- 0.3 mmHg after insulin administration). Cell-mediated collagen gel contraction can serve as an in vitro model for in vivo measurements of P(IF). Insulin induced alpha(v)beta(3)-integrin-dependent collagen gel contraction mediated by C2C12 cells. Our findings suggest a beneficiary effect of insulin for patients with sepsis with regard to the fluid balance, and this effect may in part be due to a normalization of P(IF) by a mechanism involving the integrin alpha(v)beta(3).
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| 28. |
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