-
[show abstract]
[hide abstract]
ABSTRACT: A major clinical problem in orthopedics is the healing of nonunion fractures. Limitations of this bone repair process include insufficient angiogenesis and mineralization. Integrating appropriate biomaterials with site-specific neovascularization and osteogenesis at the wound site has been the focus of several clinically relevant therapeutic strategies. As an extracellular protein, acidic fibroblast growth factor (FGF-1) induces, coordinates, and sustains site-specific molecular responses associated with angiogenesis and osteogenesis. To establish the ability of this growth factor to coordinate bone regenerative process in vivo, site-specific delivery of FGF-1, entrapped in a fibrin/hydroxyapatite composite, was evaluated. Kinetic analysis in vivo revealed the biocomposite was capable of delivering biologically active FGF-1. Release kinetics revealed an initial delivery of 87.5 ng/h of active FGF-1 in the first 20 h, followed by a reduced delivery of 28 ng/h during the next 20 h. In situ immunohistological analyses demonstrated that FGF-1-containing implants induced increased angiogenesis and infiltration of cells expressing osteogenic related markers (i.e., osteopontin, osteocalcin). Collectively, these efforts support that site-specific delivery of active FGF-1 in a fibrin/hydroxyapatite composite is competent to induce not only angiogenesis but also osteogenic cellular responses.
Journal of Biomedical Materials Research Part A 12/2004; 71(2):316-25. · 2.63 Impact Factor
-
M.N. Achasov,
R.R. Akhmetshin,
V.M. Aulchenko,
V.Sh. Banzarov,
A. Baratt,
L.M. Barkov,
S.E. Baru,
N.S. Bashtovoy,
K.I. Beloborodov,
A.V. Berdugin, [......],
A.N. Skrinsky,
I.G. Snopkov,
E.P. Solodov, J.A. Thompson,
Y.V. Usov,
A.A. Valishev,
A.V. Vasiljev,
Y.V. Yudin,
A.S. Zaitsev,
S.G. Zverev
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Magnetic Detector(CMD-2) and Spherical Neutral Detector(SND) operated at the VEPP-2M electron-positron collider in the c.m. energy range 360-1380MeV. The total integrated luminosity above 60pb–1 has been collected by both detectors. The cross sections of hadronic production have been measured with high precision. New results for the light vector meson parameters and rare decay mode were obtained.PACS: 13.66.Bc Hadron production in e–e+ interactions – 13.66.Jn Precision measurements in e–e+ interactions
European Physical Journal C 06/2004; 33:s583-s585. · 3.63 Impact Factor
-
R. R. Akhmetshin,
E. V. Anashkin,
V. M. Aulchenko,
V. Sh. Banzarov,
L. M. Barkov,
S. E. Baru,
N. S. Bashtovoy,
A. E. Bondar,
D. V. Bondarev,
A. V. Bragin, [......],
V. P. Smakhtin,
I. G. Snopkov,
E. P. Solodov,
P. Yu. Stepanov,
A. I. Sukhanov, J. A. Thompson,
V. M. Titov,
A. A. Valishev,
Yu. V. Yudin,
S. G. Zverev
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Magnetic Detector (CMD‐2) and main it’s parameters are shortly described. The results for the cross sections of e+e− annihilation into hadrons are presented in the c.m. energy range from 0.37 to 1.39 GeV. The total integrated luminosity of about 31 pb−1 has been collected. The new results for the ρ and ω meson parameters were obtained. The pion form factor was determinated with a 0.6% systematic uncertainty. The major decay modes of the ϕ meson as well as multihadron final states have been studied in a broad energy range. © 2002 American Institute of Physics
AIP Conference Proceedings. 06/2002; 619(1):15-29.
-
[show abstract]
[hide abstract]
ABSTRACT: Endogenous tyrosine nitration and inactivation of manganese superoxide dismutase (MnSOD) has previously been reported to occur during end-stage human renal allograft rejection. In order to determine whether nitration and inactivation of this critical mitochondrial protein might play a contributory role in the onset of transplant rejection, we employed a rodent model of Chronic Allograft Nephropathy (or CAN). Using this model we followed kidney function from 2-52 weeks post-transplant and correlated graft function with levels of nitration in the renal allograft. Tyrosine nitration of both glomerular and tubular structures occurred at 2 weeks post-transplant. At later times (16 weeks) post-transplant, tyrosine nitration appeared to be confined to tubular structures; however glomerular nitration returned at 52 weeks post-transplant. Interestingly, nitration and inactivation of MnSOD occurs prior to the onset of renal dysfunction in this rat model of chronic allograft nephropathy (2 weeks versus 16 weeks post-transplant). Furthermore, we have identified an additional mitochondrial protein, cytochrome c, as being endogenously nitrated during chronic rejection. The kinetics of cytochrome c nitration lagged behind MnSOD nitration and inactivation (4 weeks compared to 2 weeks); suggesting that loss of MnSOD activity likely contributes to elevation of the nitrating species and further nitration of other targets.
Free Radical Biology and Medicine 01/2002; 31(12):1603-8. · 5.42 Impact Factor
-
M Aslan,
T M Ryan,
B Adler,
T M Townes,
D A Parks, J A Thompson,
A Tousson,
M T Gladwin,
R P Patel,
M M Tarpey,
I Batinic-Haberle,
C R White,
B A Freeman
[show abstract]
[hide abstract]
ABSTRACT: Plasma xanthine oxidase (XO) activity was defined as a source of enhanced vascular superoxide (O(2)( *-)) and hydrogen peroxide (H(2)O(2)) production in both sickle cell disease (SCD) patients and knockout-transgenic SCD mice. There was a significant increase in the plasma XO activity of SCD patients that was similarly reflected in the SCD mouse model. Western blot and enzymatic analysis of liver tissue from SCD mice revealed decreased XO content. Hematoxylin and eosin staining of liver tissue of knockout-transgenic SCD mice indicated extensive hepatocellular injury that was accompanied by increased plasma content of the liver enzyme alanine aminotransferase. Immunocytochemical and enzymatic analysis of XO in thoracic aorta and liver tissue of SCD mice showed increased vessel wall and decreased liver XO, with XO concentrated on and in vascular luminal cells. Steady-state rates of vascular O(2)( *-) production, as indicated by coelenterazine chemiluminescence, were significantly increased, and nitric oxide (( *)NO)-dependent vasorelaxation of aortic ring segments was severely impaired in SCD mice, implying oxidative inactivation of ( *)NO. Pretreatment of aortic vessels with the superoxide dismutase mimetic manganese 5,10,15,20-tetrakis(N-ethylpyridinium-2-yl)porphyrin markedly decreased O(2)( small middle dot-) levels and significantly restored acetylcholine-dependent relaxation, whereas catalase had no effect. These data reveal that episodes of intrahepatic hypoxia-reoxygenation associated with SCD can induce the release of XO into the circulation from the liver. This circulating XO can then bind avidly to vessel luminal cells and impair vascular function by creating an oxidative milieu and catalytically consuming (*)NO via O(2)( small middle dot-)-dependent mechanisms.
Proceedings of the National Academy of Sciences 01/2002; 98(26):15215-20. · 9.68 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: After trauma injury to the musculoskeletal system, conditions such as ischemia and inflammation involve excess production of superoxide (O2*), nitric oxide (*NO), and their reaction product, peroxynitrite (ONOO-). Exposure of murine osteoblasts and rat-derived primary osteoblast precursors to ONOO- resulted in a dose- and time-dependent delayed cell death that was more characteristic of apoptosis than necrosis. Exposure of both cell populations to ONOO- immediately enhanced phosphorylation and nitration of tyrosine residues within several polypeptides. Treatment of osteoblasts and osteoblast precursors with exogenous acidic fibroblast growth factor (FGF-1) enhanced cellular growth, increased endogenous levels of tyrosine phosphorylation, and significantly induced expression of both osteopontin and osteocalcin messenger RNA (mRNA) as well as osteopontin protein. Pretreatment of both cell populations with exogenous FGF-1 prevented ONOO(-)-mediated death. Cell signaling induced by FGF-1 pretreatment had no major effect of total levels of tyrosine nitration after ONOO- treatment. Collectively, these in vitro efforts show that FGF-1 signaling renders osteoblasts and osteoblast precursors resistant to the cytotoxic effects of ONOO-. Consequently, results presented here predict the therapeutic use of this growth factor for promoting the progression of bone repair mechanisms after fracture trauma.
Journal of Bone and Mineral Research 11/2001; 16(10):1917-25. · 6.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Estrogen is vasoprotective in animal models of vascular injury, yet the mechanisms involved are incompletely understood. The role of inducible nitric oxide synthase (iNOS) in vascular repair is controversial, but many lines of evidence indicate that it plays a role in neointima formation after arterial injury and that 17beta-estradiol (E(2)) modulates iNOS expression. This study tested the hypothesis that E(2) reduces neointima formation after vascular injury via a mechanism that is dependent on modulation of iNOS expression.
Male and female wild-type (iNOS(+/+)) mice and mice with homozygous deletion of the iNOS gene (iNOS(-/-)) were studied intact (INT) or after ovariectomy (OVX) and implantation of E(2) or vehicle (V) pellets. Mice were randomized to 8 groups based on sex, iNOS status, OVX, and treatment with E(2) or V. Twenty-eight days after carotid artery ligation, mice were euthanized, and occluded vessels were evaluated for neointima formation by morphometric analysis. There was a marked sexual dimorphism in neointima formation in both the iNOS(+/+) mice and the iNOS(-/-) mice. iNOS(+/+) INT females had a >90% reduction in neointima formation compared with iNOS(+/+) males, and iNOS(-/-) INT females had a 65% reduction in neointima formation compared with iNOS(-/-) males. The sexually dimorphic response was attenuated by OVX and restored by E(2) replacement in both iNOS(+/+) and iNOS(-/-) mice.
These results demonstrate that the vasoprotective effects of E(2) after ligation vascular injury are, at least in part, independent of iNOS expression.
Circulation 11/2001; 104(22):2740-5. · 14.74 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have previously demonstrated that expression of the atrial natriuretic peptide (ANP) clearance receptor (NPR-C) is reduced selectively in the lung of rats and mice exposed to hypoxia but not in pulmonary arterial smooth muscle cells (PASMCs) cultured under hypoxic conditions. The current study tested the hypothesis that hypoxia-responsive growth factors, fibroblast growth factors (FGF-1 and FGF-2) and platelet-derived growth factor-BB (PDGF-BB), that activate tyrosine kinase receptors can reduce expression of NPR-C in PASMCs independent of environmental oxygen tension. Growth-arrested rat PASMCs were incubated under hypoxic conditions (1% O2) for 24 h; with FGF-1, FGF-2, or PDGF-BB (0.1-20 ng/ml for 1-24 h); or with ANG II (1-100 nM), endothelin-1 (ET-1, 0.1 microM), ANP (0.1 microM), sodium nitroprusside (SNP, 0.1 microM), or 8-bromo-cGMP (0.1 mM) for 24 h under normoxic conditions. Steady-state NPR-C mRNA levels were assessed by Northern blot analysis. FGF-1, FGF-2, and PDGF-BB induced dose- and time-dependent reduction of NPR-C mRNA expression within 1 h at a threshold concentration of 1 ng/ml; hypoxia, ANG II, ET-1, ANP, SNP, or cGMP did not decrease NPR-C mRNA levels in PASMCs under the above conditions. Downregulation of NPR-C expression by FGF-1, FGF-2, and PDGF-BB was inhibited by the selective FGF-1 receptor tyrosine kinase inhibitor PD-166866 and mitogen-activated protein/extracellular signal-regulated kinase inhibitors U-0126 and PD-98059. These results indicate that activation of tyrosine kinase receptors by hypoxia-responsive growth factors, but neither hypoxia per se nor activation of G protein-coupled receptors, inhibits NPR-C gene expression in PASMCs. These results suggest that FGF-1, FGF-2, and PDGF-BB play a role in the signal transduction pathway linking hypoxia to altered NPR-C expression in lung.
AJP Lung Cellular and Molecular Physiology 08/2001; 281(1):L155-63. · 3.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Previous immunohistochemical studies have demonstrated enhanced appearance of FGF-1 and nitrotyrosine, a footprint of reactive nitrogen species peroxynitrite (ONOO(-)), in human pancreatic adenocarcinoma. We have examined the consequences of constitutive exposure to FGF-1 in nontumorigenic rat ductal epithelial cells (ARIP). ARIP cells were transduced with either a secreted chimera of FGF-1, ARIP(FGF-1), or a control plasmid, 65 RIP(betag). These cells were evaluated for alteration in growth and morphology, responses to ONOO(-) (protein tyrosine nitration/phosphorylation), and in vivo tumor formation. ARIP(FGF-1) cells, in contrast to 65 RIP(betag), demonstrated a transformed morphology, a 2-fold increased growth rate, and enhanced protein tyrosine phosphorylation. Treatment with 150 microM ONOO(-) resulted in 86 and 7% (p <.01) death of ARIP(betag) and ARIP(FGF-1), respectively. Exposure of 65 RIP(betag) cells to ONOO(-) enhanced tyrosine phosphorylation and tyrosine nitration of several polypeptides. Cell signaling by FGF-1 enhanced both phosphorylation and nitration of tyrosine residues in target proteins modified by ONOO(-). ARIP(betag) cells failed to exhibit tumor formation in nude mice, but at d 7 in vivo cells were TUNEL and nitrotyrosine positive and FGF-1 negative. ARIP(FGF-1) cells readily formed tumor nodules, exhibiting features of pancreatic adenocarcinoma and demonstrating FGF-1-positive, nitrotyrosine-positive, and TUNEL-negative epithelium. These results suggest an interdependent role between FGF-1 and ONOO(-) during the development and progression of pancreatic adenocarcinoma.
Free Radical Biology and Medicine 05/2001; 30(9):957-66. · 5.42 Impact Factor
-
R. R. Akhmetshin,
E. V. Anashkin,
M. Arpagaus,
V. M. Aulchenko,
V. S. Banzarov,
L. M. Barkov,
S. E. Baru,
N. S. Bashtovoy,
D. V. Chernyak,
A. E. Bondar, [......],
V. A. Sidorov,
A. N. Skrinsky,
V. P. Smakhtin,
I. G. Snopkov,
E. P. Solodov,
P. Y. Stepanov,
A. I. Sukhanov,
Y. V. Yudin,
S. G. Zverev, J. A. Thompson
Physics Letters B 04/2001; 508:217-218. · 3.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Skeletal injury and associated ischemia and inflammation induce the generation of pro-oxidants such as peroxynitrite (ONOO-), which has been demonstrated to induce apoptosis in several cell lines. Fibroblast growth factor (FGF-1) is important for coordinating osteogenesis and angiogenesis of osseous repair. In vitro studies were performed examining the effect of FGF-1 on human osteoblast progenitor stromal stem (HSS) cell proliferation, differentiation, and response to ONOO-.
HSS cells were isolated and growth kinetics determined in the presence and absence of FGF-1. The effect of FGF-1 on HSS cell expression of osteoblast-specific osteopontin and osteocalcin mRNA and protein was examined by reverse transcriptase polymerase chain reaction and Western blot techniques. To determine the sensitivity of HSS cells to ONOO- in the absence and presence of FGF-1 pretreatment, cells were exposed to varying concentrations of the oxidant and examined for cell death using quantitative fluorescence staining with fluorescein diacetate and propidium diacetate.
Treatment of HSS cells with FGF-1 significantly enhanced cellular growth rates by 5 days (4.6 x 105 cells/mL vs. 3.1 x 105 cells/mL) and induced expression of both osteopontin and osteocalcin mRNA and protein. Exposure of HSS cells to ONOO- resulted in a dose- and time-dependent delayed cell death that was more characteristic of apoptosis than necrosis. Pretreatment of HSS cells with FGF-1 prevented ONOO- mediated apoptosis.
In vitro, treatment of HSS cells with FGF-1 stimulates cell growth and induces expression of differentiation markers specific to osteoblasts. FGF-1 treatment renders osteoblast precursors resistant to the cytotoxic effects of ONOO-. These results suggest that FGF-1 promotes the progression of bone repair mechanisms by increasing the population of osteoblasts and imparting protection to the cell line from the hostile inflammatory environment.
The Journal of trauma 04/2001; 50(3):433-8; discussion 439. · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Chronic allograft nephropathy (CAN), a major problem in renal transplantation, is related to both alloantigen-dependent and -independent processes. Because dietary salt intake modulated glomerular production of transforming growth factor-beta, which has been shown to play an important role in CAN, we hypothesized that dietary salt would directly enhance renal injury in a rodent model of CAN.
Dietary NaCl was increased from 1.0% (normal) to 8.0% in a group of Fisher/Lewis rats 25 days following orthotopic renal transplantation and was continued until 16 weeks after transplantation.
Blood pressure, which was recorded using radiotelemetry in the first eight-weeks post-transplantation, did not differ between the groups, but allograft recipients on the 8.0% NaCl diet rapidly demonstrated increased urinary albumin excretion. Renal function determined by dynamic functional imaging was worse in allograft recipients on the 8.0% NaCl diet by six weeks following transplantation. Histologic examination at 16 weeks confirmed a significant increase in allograft damage in the 8.0% NaCl group compared with allografts from rats on 1.0% NaCl diet. These findings included glomerulosclerosis and tubulointerstitial injury that consisted of fibrosis, tubular atrophy and dilation, intratubular casts, and tubular epithelial cell damage. Small arteries and arterioles did not show evidence of damage from hypertension or other abnormality.
In this model of CAN, renal allograft dysfunction preceded hypertension and was accelerated significantly by an increase in dietary salt.
Kidney International 04/2001; 59(3):1149-57. · 6.61 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Early immunologic and non-immunologic injury of renal allografts adversely affects long-term graft survival. Some degree of preservation injury is inevitable in cadaveric renal transplantation, and, with the reduction in early acute rejection, this non-immunologic injury has assumed a greater relative importance. Optimal graft preservation will maximize the chances of early graft function and long-term graft survival, but the best method of preservation pulsatile perfusion (PP) versus cold storage (CS) is debated.
Primary cadaveric kidney recipients from January 1990 through December 1995 were evaluated. The effects of implantation warm ischemic time (WIT) ( < or = 20 min, 21-40 min, or > 40 min) and total ischemic time (TIT) ( < or > or = 20 h) on death-censored graft survival were compared between kidneys preserved by PP versus those preserved by CS. The effect of preservation method on delayed graft function (DGF) was also examined.
There were 568 PP kidneys and 268 CS kidneys. Overall death-censored graft survival was not significantly different between groups, despite worse donor and recipient characteristics in the PP group. CS kidneys with an implantation WIT > 40 min had worse graft survival than those with < 40 min (p = 0.0004). Survival of PP kidneys and those transplanted into 2 DR-matched recipients was not affected by longer implantation WIT. Longer TIT did not impact survival. DGF was more likely after CS preservation (20.2% versus 8.8%, p = 0.001).
Preservation with PP improves early graft function and lessens the adverse effect of increased warm ischemia in cadaveric renal transplantation. This method is likely associated with less preservation injury and/or increases the threshold for injury from other sources and is superior to CS.
Clinical Transplantation 12/2000; 14(6):543-9. · 1.67 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Previous in vitro studies have suggested that estrogen attenuates the vascular injury response by modulating vascular smooth muscle cell (VSMC) expression of soluble factor(s) directing migration of adventitial fibroblasts. Previous in vivo studies have established a role for osteopontin (OPN) and its integrin receptors after vascular injury. In this study, we examined OPN expression in activated VSMCs, its modulation by estrogen, and its effects on adventitial fibroblast migration. In addition, the relative functional roles of beta(1)- and beta(3)-integrin-matrix interactions were examined.
Primary cultures of VSMCs and adventitial fibroblasts were derived from female Sprague-Dawley rats. Serum-activated VSMCs expressed high levels of OPN mRNA and secreted protein that was effectively inhibited by estrogen treatment (10(-7) mol/L). Compared with VSMCs, fibroblasts expressed similar levels of integrins alphanu and beta(1) and higher levels of integrin-beta(3). Exogenous OPN (5.0 to 40 microg/mL) directed fibroblast migration in a dose-dependent fashion. Anti-beta(3)-integrin antibody (F11) pretreatment markedly inhibited adventitial fibroblast migration directed by exogenous OPN or VSMC-conditioned medium in a dose-dependent manner. In contrast, anti-beta(1)-integrin antibody (Ha2/5) did not affect fibroblast migration. Similarly, pretreatment with either linear or cyclic RGD peptides (10 to 1000 micromol/L) inhibited fibroblast migration directed by OPN or VSMC-conditioned medium in a dose-dependent manner.
These observations suggest that estrogen indirectly attenuates integrin-beta(3)-dependent adventitial fibroblast migration after inhibition of OPN expression in VSMCs.
Circulation 07/2000; 101(25):2949-55. · 14.74 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: During pancreatic tumorigenesis, the equilibrium between cell survival and cell death is altered, allowing aggressive neoplasia and resistance to radiation and chemotherapy. Local oxidative stress is one mechanism regulating programmed cell death and growth and may contribute to both tumor progression and suppression. Our recent in situ immunohistochemical studies demonstrated that levels of total nitrotyrosine, a footprint of the reactive nitrogen species peroxynitrite, are elevated in human pancreatic ductal adenocarcinomas. In this study, quantitative HPLC-EC techniques demonstrated a 21- to 97-fold increase in the overall levels of nitrotyrosine of human pancreatic tumor extracts compared to normal pancreatic extracts. Western blot analysis of human pancreatic tumor extracts showed that tyrosine nitration was restricted to a few specific proteins. Immunoprecipitation coupled with Western analysis identified c-Src tyrosine kinase as a target of both tyrosine nitration and tyrosine phosphorylation. Peroxynitrite treatment of human pancreatic carcinoma cells in vitro resulted in increased tyrosine nitration and tyrosine phosphorylation of c-Src kinase, increased (>2-fold) c-Src kinase activity, and increased association between c-Src kinase and its downstream substrate cortactin. Collectively, these observations suggest that peroxynitrite-mediated tyrosine nitration and tyrosine phosphorylation of c-Src kinase may lead to enhanced tyrosine kinase signaling observed during pancreatic ductal adenocarcinoma growth and metastasis.
Archives of Biochemistry and Biophysics 06/2000; 377(2):350-6. · 2.93 Impact Factor
-
The American Journal of Cardiology 06/2000; 85(10):1276-9. · 3.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Recombinant human acidic fibroblast growth factor (FGF-1) was radiolabeled with (99m)Tc by the HYNIC method. The (99m)Tc-FGF-1 retained its representative molecular mass, heparin affinity, cellular binding to both low (Kd = 9.5 nM) and high (Kd = 125 pM) affinity sites, and mitogenic activity. Gamma camera imaging after intravenous dosing in rats confirmed high liver and kidney binding. Heparin significantly decreased (99m)Tc-FGF-1 liver uptake and increased urinary excretion. These studies illustrate a new method for imaging FGF-1 targeting under various conditions.
Nuclear Medicine and Biology 06/2000; 27(4):407-14. · 3.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Previous studies have shown that estrogen (E2) is vasoprotective in multiple animal models of vascular injury, including mice with homologous disruptions of either the alpha or beta isoforms of the estrogen receptor (ER) gene, calling into question the ER dependency of the vasoprotective effect. This study used ICI 182,780, a nonselective ER antagonist, to test the hypothesis that the vasoprotective effect of E2 in the rat carotid injury model is ER mediated.
Intact female Sprague-Dawley rats were divided into 4 groups and treated with the nonselective ER antagonist ICI 182,780 (ICI; 0.5, 1.5, or 5 mg. kg(-1). d(-1), subcutaneously [S.C.]) or vehicle, beginning before balloon injury of the right common carotid artery and continuing for 14 days afterward. Four groups of ovariectomized rats (OVX) were treated with 17beta estradiol (E2) (20 microgram. kg(-1). d(-1), S.C.) alone or combined with ICI 5 mg. kg(-1). d(-1), S.C.; with ICI 5 mg. kg(-1). d(-1) alone; or with vehicle according to a similar protocol. Two weeks after injury, rats were killed, and the carotid arteries were evaluated for neointima formation using morphometric analysis. ICI 182,780 blunted the E2-related protective effect and increased neointima formation in injured carotid arteries of intact female rats in a dose-dependent fashion. ICI had no effect on neointima formation in OVX, but addition of ICI to E2 in OVX blocked the inhibitory effect of exogenous E2 on neointima formation.
These results indicate that the vasoprotective effect of E2 in the balloon-injured rat carotid artery model is mediated by ER.
Circulation 06/2000; 101(20):2342-4. · 14.74 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Clinical and experimental evidence suggest that the adventitia participates in the response to endoluminal vascular injury. The current study used a direct approach to test the hypothesis that, after balloon injury of the rat carotid artery, adventitial fibroblasts migrate in a luminal direction and contribute to neointima formation.
Primary syngeneic adventitial fibroblasts were stably transduced with retroviral particles coordinating expression of beta-galactosidase (LacZ) and introduced into the adventitia of right carotid arteries of rats immediately after balloon injury. At defined times after injury and fibroblast implantation, rats were euthanized, and arterial tissue was examined for detection of LacZ mRNA (reverse transcription polymerase chain reaction), DNA (polymerase chain reaction), and in situ enzymatic activity. LacZ expression was detected in the media 5 days postinjury and in both media and neointima at 7, 10, and 14 days postinjury. LacZ was undetectable in injured vessels that had not been seeded with transduced fibroblasts and was restricted to the adventitia in seeded vessels that were not injured.
These observations provide direct demonstration of adventitial fibroblast migration into neointima of arteries after endoluminal injury.
Circulation 04/2000; 101(12):1362-5. · 14.74 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Increasing evidence suggests that glutathione (GSH) synthesis is a regulated process. Documented increases in gamma-glutamylcysteine synthetase (GCS) occur in response to oxidants, in tumors, on plating cells at a low cell density, and with nerve growth factor stimulation, suggesting that GSH synthesis may be related to the cell growth and transformation. Previously, extracellular acidic fibroblast growth factor (FGF-1) has been demonstrated to cause transformation and aggressive cell growth in murine embryonic fibroblasts. In the present investigation, we sought to determine whether FGF-1, with its growth inducing properties, resulted in the modulation of GSH biosynthetic enzymes, GCS and GSH synthetase. Murine fibroblasts transduced with (hst/KS)FGF-1, a chimeric human FGF-1 gene containing a signal peptide sequence for secretion, displayed elevated gene expression of both heavy and light subunits of GCS. Activity of GSH synthetase was also elevated in these cells compared with control cells. Nonetheless, GSH was decreased in the FGF-1-transduced cells along with high energy phosphates, adenine nucleotides, NADH, and the redox poise. However, GSSG was not elevated in these cells. Fibroblasts stably expressing human immunodeficiency virus type 1 Tat, which induces intrinsic FGF-1 secretion, resulted in similar changes in GCS, GS, and GSH. The results suggest that although increases in the enzymes of GSH synthesis are a common response to growth factors, an increase in GSH content per se is not required for altered cell growth.
Archives of Biochemistry and Biophysics 04/2000; 375(1):201-9. · 2.93 Impact Factor
