Donate Help Contact The AHA Sign In Home
American Heart Association
Hypertension
Search: search_blue_button Advanced Search
Hypertension. 1997;29:683-689

This Article
Right arrow Abstract Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Komatsu, S.
Right arrow Articles by Granger, D. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Komatsu, S.
Right arrow Articles by Granger, D. N.

(Hypertension. 1997;29:683-689.)
© 1997 American Heart Association, Inc.


Articles

Effects of Chronic Arterial Hypertension on Constitutive and Induced Intercellular Adhesion Molecule-1 Expression In Vivo

Shunichiro Komatsu; Julian Panes; Janice M. Russell; Donald C. Anderson; Vladimir R. Muzykantov; Masayuki Miyasaka; D. Neil Granger

the Department of Physiology, LSU Medical Center, Shreveport, La (S.K., J.P., J.M.R., D.N.G.); Discovery Research, Upjohn Laboratories, Kalamazoo, Mich (D.C.A.); Institute for Environmental Medicine, University of Pennsylvania, Philadelphia (V.R.M.); and Department of Bioregulation, Biomedical Research Center, Osaka (Japan) University Medical School (M.M.).

Correspondence to D. Neil Granger, PhD, Department of Physiology, LSU Medical Center, 1501 Kings Hwy, Shreveport, LA 71130-3932. E-mail dgrang@lsumc.edu


*    Abstract
up arrowTop
*Abstract
down arrowIntroduction
down arrowMethods
down arrowResults
down arrowDiscussion
down arrowReferences
 
Recent reports indicate that bacterial endotoxin (lipopolysaccharide) and cytokines elicit a more profound increase in the surface expression of intercellular adhesion molecule-1 (ICAM-1) in cultured endothelial cells derived from spontaneously hypertensive (SHR) versus normotensive Wistar-Kyoto rats (WKY). Our objective in this study was to characterize and compare in vivo ICAM-1 expression in SHR and WKY under basal conditions and after 5 hours of endothelial cell activation with either lipopolysaccharide (5 mg/kg IP) or tumor necrosis factor-{alpha} (TNF-{alpha}; 1, 5, and 10 µg/kg IP). ICAM-1 expression was quantified in different tissues by the double-radiolabeled monoclonal antibody technique. When constitutive (baseline) ICAM-1 expression was corrected for endothelial cell surface area, significantly higher values were noted in SHR than WKY but only in splanchnic organs. Lipopolysaccharide and TNF-{alpha} elicited significant increases in ICAM-1 expression in all tissues of both WKY and SHR. However, the magnitude of the lipopolysaccharide-induced ICAM-1 upregulation in heart, stomach, skeletal muscle, and brain was significantly lower in SHR than WKY. A similar blunted ICAM-1 upregulation was noted in the stomach of SHR after administration of 5 µg/kg TNF-{alpha}. The differences in induced ICAM-1 expression between SHR and WKY do not appear to be due to differences in endothelial cell surface area or plasma glucocorticoid levels. These results suggest that chronic arterial hypertension results in altered ICAM-1 expression on the endothelium, which may contribute to the abnormal inflammatory responses associated with this disease.


Key Words: endothelium • rats, inbred SHR • angiotensin-converting enzyme • tumor necrosis factor-{alpha} • lipopolysaccharide • glucocorticoid


*    Introduction
up arrowTop
up arrowAbstract
*Introduction
down arrowMethods
down arrowResults
down arrowDiscussion
down arrowReferences
 
The adhesion of leukocytes to vascular endothelial cells (LECA) is a critical early step in the development of an inflammatory response.1 2 3 The process of LECA is coordinated by complex interactions between surface glycoproteins on leukocytes and their corresponding counterreceptors on endothelial cells. The ß2 subfamily of integrins (CD18) are expressed on leukocytes4 5 and bind to glycoproteins of the immunoglobulin superfamily, such as ICAM-1 and ICAM-2, which are expressed on vascular endothelium.6 7 Both ICAM-1 and ICAM-2 are constitutively expressed on the surface of endothelial cells grown in culture. Stimulation of endothelial cell monolayers with either endotoxin or cytokines leads to increased ICAM-1 expression,8 which results in an increased binding of neutrophils and lymphocytes to endothelial cells.9

Although leukocyte adhesion to endothelial cells is essential for host defense and repair, it is now recognized that adherent leukocytes can also mediate the endothelial cell injury and microvascular dysfunction that are associated with a number of cardiovascular diseases, including ischemic disorders10 11 12 and atherogenesis.13 Recent reports indicate that some of the risk factors for cardiovascular diseases such as hypertension,14 15 diabetes,16 and hypercholesterolemia17 can exert a profound influence on the adhesive interactions between activated leukocytes and vascular endothelial cells. For example, the results of in vitro studies indicate that endotoxin- or cytokine-stimulated ICAM-1 expression14 and monocyte adhesion15 occur more intensely on endothelial cells derived from SHR than cells from normotensive WKY, suggesting that endothelial cells exposed to chronic arterial hypertension may sustain a higher level of leukocyte adhesion than their normotensive counterparts. However, these observations appear to be inconsistent with in vivo studies that demonstrate blunted LECA interactions elicited by platelet-activating factor, leukotriene B4, 18 or histamine19 20 in SHR compared with WKY.

Recently, a novel approach for in vivo quantification of endothelial cell adhesion molecule expression was developed based on the use of dual radiolabeled mAbs.21 Since this technique appears to detect ICAM-1 expression with a precision not previously attained by histochemical procedures, it represents a potentially powerful tool for assessment of the factors that regulate ICAM-1 expression in various pathological conditions. Hence, we used the dual radiolabeled mAb technique in the present study to characterize and compare in vivo ICAM-1 expression in SHR and WKY under basal conditions and after endothelial cell stimulation with either LPS or TNF-{alpha}. Since chronic hypertension may lead to anatomic changes in microvessel density and endothelial cell surface area,22 23 24 we used a radiolabeled mAb directed against ACE, which is expressed on the luminal surface of vascular endothelium, to determine whether SHR and WKY exhibit differences in endothelial cell surface area on a per gram tissue basis.


*    Methods
up arrowTop
up arrowAbstract
up arrowIntroduction
*Methods
down arrowResults
down arrowDiscussion
down arrowReferences
 
Monoclonal Antibodies
The mAbs used for the in vivo assessment of ICAM-1 expression were 1A29, a mouse IgG1 against rat ICAM-125 ; P-23, a nonbinding murine IgG1 directed against human P-selectin26 ; CL26, a mouse IgG1 against rat CD1827 ; and 9B9, a mouse IgG1 directed against human ACE that cross-reacts with rat and monkey ACE.28 MAbs 1A29, P-23, and CL26 were scaled up and purified by protein A-G chromatography (Pharmacia & Upjohn). Dr Sergey M. Danilov generously provided mAb 9B9.

Radioiodination of mAbs
The binding mAbs directed against either ICAM-1 (1A29) or ACE (9B9) were labeled with 125I (DuPont-NEN), and the nonbinding mAb (P-23) was labeled with 131I. The chloramine T method29 was used for labeling mAbs 1A29 and P-23. Briefly, a 1-mg aliquot of mAb in 1.5 mL sodium phosphate buffer (pH 7.4) was added to 125I or 131I, with a total activity of 1.0 mCi, and 100 µg chloramine T. The mixture was incubated for 1 minute at room temperature, and 62.5 µg sodium metabisulfite was added. Radioiodination of mAb 9B9 with 125I was performed by the iodogen method,30 which was also used for labeling of 1A29 in the aortic expression studies. Briefly, 250 µg protein was incubated with 250 µCi sodium 125I and 125 µg iodogen at 4°C for 12 minutes. After radioiodination by either the chloramine T or iodogen method, the radiolabeled mAbs were separated from free 125I by gel filtration on a Sephadex PD-10 column (Pharmacia LKB). The column was equilibrated with phosphate buffer containing 1% bovine serum albumin and eluted with the same buffer. Two fractions of 2.5 mL each were collected, the second of which contained the labeled antibody. Absence of free 125I or 131I was ensured by extensive dialysis of the protein-containing fraction. Less than 1% of the activity of the protein fraction was recovered from the dialysis fluid. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis showed normal heavy and light chain moieties of expected molecular weights. Labeled mAbs were stored in 500-µL aliquots at 4°C and used within 3 weeks after the labeling procedure. The specific activity of labeled mAbs was 0.5 µCi/µg.

Animal Procedures
Male SHR (8 to 10 weeks old, n=78) and age-matched WKY (n=78) weighing 200 to 240 g were obtained from Harlan Laboratories (Frederick, Md). Anesthesia was induced by intraperitoneal injection of thiobutabarbital (Inactin, RBI) at a dose of 120 mg/kg body wt. A tracheostomy was performed on each rat to facilitate breathing throughout the experiment, and the right carotid artery and right jugular vein were cannulated. Systemic arterial pressure was measured with a Statham P23A pressure transducer and recorded with a Grass polygraph D.C. driver amplifier. For measurement of ICAM-1 expression, a mixture of 5 µg 125I–ICAM-1 mAb (1A29), 5 µg 131I–nonbinding mAb (P-23), and 100 µg unlabeled ICAM-1 mAb was administered through the jugular vein catheter. This dose of ICAM-1 mAb has been shown to saturate all the relevant adhesion receptors expressed on vascular endothelial cells.21 For estimation of aortic ICAM-1 expression, 50 µg (instead of 100 µg) unlabeled ICAM-1 mAb was administered, since the binding of labeled ICAM-1 to aortic endothelium was too low for accurate estimates of surface expression with the 100-µg dose of cold mAb. An increased TNF-{alpha}–induced ICAM-1 expression was readily detected with the lower dose of cold mAb, indicating levels sufficient to saturate ICAM-1 aortic endothelium.

We recently reported that the binding of an ACE-specific mAb (9B9) on vascular endothelium is well correlated with morphological estimates of endothelial surface area in different tissues.31 Hence, in some experiments on SHR and WKY, estimates of tissue endothelial surface area were obtained via administration of a mixture of 5 µg 125I-9B9 mAb, 5 µg 131I–P-23, and 25 µg unlabeled 9B9 through the jugular vein catheter. Blood samples were obtained through the carotid artery catheter at 2.5 and 5 minutes after injection of the mAb mixture. Thereafter, the rats were heparinized (1 mg/kg sodium heparin) and rapidly exsanguinated by vascular perfusion with sodium bicarbonate buffer via the jugular vein and simultaneous blood withdrawal via the carotid artery. The inferior vena cava was then severed at the thoracic level, and the carotid artery was perfused with sodium bicarbonate buffer. After completion of the exchange transfusion, organs were harvested and weighed.

Calculation of ICAM-1 Expression
125I (binding mAb) and 131I (nonbinding mAb) activities in different organs and in 100-µL aliquots of cell-free plasma were counted in a gamma counter (14800 Wizard 3, Wallac), with automatic correction for background activity and spillover. The injected activity in each experiment was calculated by counting a 5-µL sample of the mixture containing the radiolabeled mAbs. The radioactivities remaining in the tube used to mix the mAbs, the syringe used to inject the mixture, and the jugular vein catheter were subtracted from the total calculated injected activity. The accumulated activity of each mAb in an organ was expressed as the percentage of the injected dose (% I.D.) per gram of tissue. The formula used for calculation of ICAM-1 expression was ICAM-1 Expression=[(% I.D./g for 125I)-(% I.D./g for 131I)x(% I.D. 125I in Plasma)]/(% I.D. 131I in Plasma). We modified this formula from the original method21 to correct the tissue accumulation of nonbinding mAb for the relative plasma levels of both binding and nonbinding mAbs. We converted this value, expressed as % I.D., to micrograms mAb per gram tissue by multiplying the above value by the total injected binding mAb (micrograms) and dividing by 100. We used an identical procedure to estimate the relative binding of mAb 9B9 and endothelial surface area in different tissues.

Experimental Protocols
To compare constitutive and LPS- and TNF-induced ICAM-1 expressions in WKY and SHR, we used the following general protocol. Constitutive ICAM-1 expression was assessed by injecting the mixture of radiolabeled (125I-1A29 and 131I–P-23) and unlabeled (1A29) mAbs into untreated rats (10 rats per group), with the tissues harvested as described above. The magnitude of endotoxin-induced ICAM-1 expression in different tissues was determined 5 hours after injection of a single dose (5 mg/kg IP) of Salmonella abortus equi LPS (Sigma Chemical Co), a dose that was recently shown to induce significant ICAM-1 expression in rats21 (8 rats per group). Dose-response characterization of ICAM-1 expression in WKY and SHR was performed with recombinant murine TNF-{alpha} (1.3x105 U/µg, R&D Systems) at doses of 1, 5, and 10 µg/kg IP,32 with organs harvested 5 hours after TNF-{alpha} administration (6 to 8 rats per group). In another series of experiments, the glucocorticoid receptor antagonist RU-486 (2.0 or 20 mg/kg IP) was administered 1 hour before LPS (5 mg/kg) administration in SHR and WKY. To exclude the possible influence of LPS-induced leukocyte plugging and/or intravascular coagulation on ICAM-1 binding to vascular endothelium, we pretreated some rats with 100 µg of an mAb (CL26) directed against the leukocyte adhesion molecule CD11/CD18 plus 1 U/g body wt of heparin at 5 minutes before LPS injection. Relative endothelial cell surface area per gram tissue was determined by measurement of the binding of an mAb against ACE in the microvasculature of WKY and SHR under basal conditions and after 5 hours of treatment with either LPS (5 mg/kg) or TNF-{alpha} (5 µg/kg, 4 to 5 rats per group). In some experiments, ICAM-1 expression was measured in the aorta of WKY and SHR under basal conditions and 5 hours after treatment with TNF-{alpha} (5 µg/kg, 5 to 6 rats per group).

Statistics
Data were analyzed by ANOVA with Scheffe's (post hoc) test. Either paired or unpaired Student's t test was used when only two groups were compared. All values are presented as mean±SE. Statistical significance was set at a value of P<.05.


*    Results
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowMethods
*Results
down arrowDiscussion
down arrowReferences
 
Effects of LPS and TNF-{alpha} on ICAM-1 Expression
ICAM-1 expression increased in a dose-dependent manner after TNF-{alpha} administration in all organs studied in both WKY and SHR. ICAM-1 expression also increased in response to LPS. Pretreatment with mAb CL26 and heparin did not affect LPS-induced ICAM-1 expression in SHR (Fig 1Down).






View larger version (147K):
[in this window]
[in a new window]
 
Figure 1. Effects of LPS and increasing doses of TNF-{alpha} on ICAM-1 expression in heart (a), stomach (b), skeletal muscle (c), and brain (d) of WKY (open bars) and SHR (shaded bars; hatched bars indicate SHR plus CL26 and heparin). Control: n=10 per group; 1 µg/kg TNF-{alpha}: n=6 WKY, n=5 SHR; 5 µg/kg TNF-{alpha}: n=8 per group; 10 µg/kg TNF-{alpha}: n=7 WKY, n=6 SHR; LPS: n=8 per group; CL26: n=3. *P<.05,**P<.01 vs WKY; +P<.01 vs control.

Comparison of Induced ICAM-1 Expression Between WKY and SHR
Although constitutive ICAM-1 expression did not differ significantly between the two rat groups, LPS-induced ICAM-1 expression was significantly lower in SHR than WKY in all organs studied (Fig 1Up). ICAM-1 expression induced by 5 µg/kg TNF-{alpha} was significantly lower in SHR than WKY but only in stomach (Fig 1bUp). No significant differences were noted between WKY and SHR treated with either 1 or 10 µg/kg TNF-{alpha} (Fig 1Up).

Differential Responsiveness of WKY and SHR to LPS and TNF-{alpha}
The responsiveness of ICAM-1 expression to 5 mg/kg LPS, normalized relative to constitutive ICAM-1 expression, was significantly lower in SHR than WKY in heart, stomach, skeletal muscle, and brain (Fig 2Down). The responsiveness of ICAM-1 expression to 5 µg/kg TNF-{alpha} was significantly lower in SHR than WKY but only in stomach (Fig 2Down). No significant differences were noted between WKY and SHR treated with either 1 or 10 µg/kg TNF-{alpha}.



View larger version (28K):
[in this window]
[in a new window]
 
Figure 2. Changes in ICAM-1 expression in response to either LPS (5 mg/kg) or TNF-{alpha} (5 µg/kg) in heart, stomach, skeletal muscle, and brain of WKY (open bars, n=8) and SHR (shaded bars, n=8). Data are normalized relative to constitutive ICAM-1 expression in the corresponding group and organ. *P<.05,**P<.01 vs WKY.

Binding of mAb Against ACE
Under baseline conditions, binding of anti-ACE mAb was comparable in SHR and WKY for all organs studied except stomach, in which SHR exhibited lower mAb 9B9 binding (Fig 3Down). Although neither 5 mg/kg LPS nor 5 µg/kg TNF-{alpha} (at 5 hours) elicited a remarkable change in mAb 9B9 in heart, skeletal muscle, or brain, a significant increase was noted in the stomach of SHR (Fig 3Down). Consequently, WKY and SHR exhibited comparable levels of 9B9 binding on endothelial cells of all organs studied after exposure to LPS or TNF-{alpha}.



View larger version (31K):
[in this window]
[in a new window]
 
Figure 3. ACE expression in the unstimulated (constitutive) microvasculature of WKY (open bars) and SHR (shaded bars) and 5 hours after intraperitoneal administration of LPS (5 mg/kg) or TNF-{alpha} (5 µg/kg). **P<.01 vs WKY.

ICAM-1 Expression Normalized for Endothelial Surface Area (ACE Expression)
When ICAM-1 expression was normalized relative to corresponding values for ACE expression in each organ of WKY and SHR, to compensate for any differences in endothelial surface area between the two groups, constitutive ICAM-1 expression was significantly higher in SHR than WKY in the stomach (Fig 4Down) and other splanchnic organs, such as pancreas, mesentery, and small and large intestines (data not shown).



View larger version (30K):
[in this window]
[in a new window]
 
Figure 4. Constitutive ICAM-1 expression corrected for corresponding ACE expression (based on the mean values of ACE expression in the corresponding group and organ) in WKY (open bars, n=10) and SHR (shaded bars, n=10). **P<.001 vs WKY.

ICAM-1 Expression on Aortic Endothelial Cells
TNF-{alpha} (5 µg/kg) significantly increased ICAM-1 expression on aortic endothelium of both WKY and SHR. However, no significant differences were noted between the two groups relative to either constitutive or TNF-{alpha}–induced ICAM-1 expression (Fig 5Down).



View larger version (45K):
[in this window]
[in a new window]
 
Figure 5. Constitutive (n=5, each group) and TNF-{alpha} (5 µg/kg)–induced (n=6, each group) ICAM-1 expression in the aorta of WKY (open bars) and SHR (shaded bars). +P<.05.

Effects of Glucocorticoid Inhibition on ICAM-1 Expression
The glucocorticoid receptor antagonist RU-486 did not affect constitutive ICAM-1 expression in the heart of either WKY or SHR at any dose studied (2 and 20 mg/kg). Although the differences in LPS (5 mg/kg)–induced ICAM-1 expression normally observed in WKY and SHR were not affected by pretreatment with 2 mg/kg RU-486, the higher dose (20 mg/kg) abolished the difference in LPS-induced ICAM-1 expression between the hearts of WKY and SHR (Fig 6Down). A similar pattern of ICAM-1 expression in response to RU-486 was noted in other organs (data not shown).



View larger version (37K):
[in this window]
[in a new window]
 
Figure 6. Effects of RU-486 on ICAM-1 expression in the heart of WKY (open bars) and SHR (shaded bars). For constitutive determinations, n=3 at both 2 and 20 mg/kg RU-486; for LPS treatment groups, n=5 at 2 mg/kg and n=6 at 20 mg/kg RU-486. *P<.01 vs WKY.


*    Discussion
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowMethods
up arrowResults
*Discussion
down arrowReferences
 
A growing body of evidence suggests that alterations in immune function may account for some of the end-organ injury associated with chronic arterial hypertension. Some of the manifestations of this altered immune function in hypertensive individuals and/or animal models of hypertension include an increased number of circulating leukocytes,33 34 a larger number of activated circulating granulocytes,33 35 36 37 and a blunted LECA response to in flammatory mediators.18 19 20 Inasmuch as adhesion molecules expressed on the surface of leukocytes (CD11/CD18, L-selectin) and endothelial cells (ICAM-1, P-selectin) are recognized as major determinants of the level of LECA sustained by the microvasculature, it has been proposed that the altered immune function in chronic arterial hypertension is likely to reflect an abnormal expression of these adhesion glycoproteins on the surface of circulating leukocytes and/or endothelial cells. For example, Schmid-Schonbein and associates38 have invoked a blunted expression of P-selectin on vascular endothelial cells to explain the attenuated histamine-induced recruitment of leukocytes in mesenteric venules of SHR compared with WKY. An altered expression of other endothelial cell adhesion molecules such as ICAM-1 may occur as well because lipid mediators (leukotriene B4, platelet-activating factor) that are known to promote LECA through ß2-integrin–ICAM adhesive interactions also elicit a blunted response in mesenteric venules of SHR compared with WKY.18 However, the possibility that an altered ICAM-1 expression on SHR endothelial cells may explain the latter findings is not consistent with studies performed on cultured endothelial cells harvested from either SHR or WKY, in that SHR endothelial cells exhibit a higher level of ICAM-1 expression in response to LPS and cytokines.14

The present study represents the first attempt to determine whether SHR exhibit an altered expression (relative to WKY) of ICAM-1 on the endothelium either under baseline (constitutive) conditions or after endothelial cell stimulation with cytokines and LPS. This analysis was made possible only recently as a result of the development of a technique that allows for quantification of endothelial cell adhesion molecules with differentially radiolabeled mAbs directed against ICAM-1 or other proteins expressed on the surface of vascular endothelium (eg, ACE). Previous applications of this technique have revealed the time course and magnitude of ICAM-1 expression in different rat tissues after intraperitoneal administration of LPS21 or of E-selectin expression in porcine skin after intradermal injection of interleukin-1.39 Hence, the findings of the present study that TNF-{alpha} elicits a dose-dependent increase in ICAM-1 expression in different tissues of both SHR and WKY represent novel information that should extend our understanding of the ability of this cytokine to promote the accumulation of inflammatory cells in different pathological states.

Our findings on the constitutive expression of ICAM-1 in different WKY and SHR tissues are consistent with the results of a recent study that demonstrated significant basal expression of the endothelial cell adhesion molecule in different tissues of Sprague-Dawley rats, with significant organ-to-organ variations in the constitutive level of ICAM-1 expression.21 Indeed, the magnitude of basal ICAM-1 expression that we noted in different WKY and SHR tissues is very similar to that measured in the same tissues of Sprague-Dawley rats with the same technique. Panes et al21 observed that much of the difference in ICAM-1 expression between tissues could be explained by comparable differences in endothelial cell surface area; ie, once ICAM-1 expression was normalized to endothelial cell surface area, the level of constitutive expression was similar in most tissues studied.

The results of the present study indicate that constitutive ICAM-1 expression in the microvasculature of all tissues (as well on aortic endothelium) does not differ between WKY and SHR. To correct for regional differences in endothelial cell surface area, we also normalized ICAM-1 expression to the surface expression of ACE (an endothelial cell surface marker) in the same tissues. When basal expression was normalized to the endothelial cell surface marker (ACE), the stomach and other splanchnic organs exhibited a significantly higher surface expression of ICAM-1 in SHR than WKY.

In studies of stroke-prone SHR (SHRSP) and WKY, the gene encoding for ACE has been proposed as a candidate gene in the genesis of hypertension in SHRSP.40 41 Although a higher lung ACE activity was noted in SHRSP than in WKY,42 no such difference was noted between the two groups (WKY versus SHR or SHRSP) for other tissues such as mesenteric arteries, kidney, and brain.42 43 To circumvent some of the limitations inherent in the use of anti-ACE mAbs in SHR (where surface expression of the enzyme could be affected), future studies could use mAbs directed against other endothelial cell surface proteins, such as PECAM-1.

Although few differences in ICAM-1 expression were noted between WKY and SHR under basal conditions, a blunted upregulation of ICAM-1 expression in different SHR tissues was consistently noted (relative to WKY) after endothelial cell stimulation with LPS. An increased adhesion of leukocytes to ICAM-1, intravascular coagulation, or both are unlikely explanations for the blunted responses to LPS in SHR because pretreatment with a CD11/CD18-specific mAb (CL26) and heparin did not alter the ICAM-1 upregulatory response to LPS. Furthermore, TNF-{alpha} and LPS did not alter the binding of an anti-ACE mAb to endothelial cells in organs such as the heart, in which a decline in ACE expression would be expected with microcirculatory dysfunction or endothelial destruction. The blunted response of ICAM-1 upregulation was also noted in splanchnic organs of SHR receiving an intermediate dose of TNF-{alpha}.

The blunted ICAM-1 upregulation observed after LPS in the brain (Figs 1d and 2UpUp) is inconsistent with published findings based on cultured endothelial cells derived from WKY and SHR brain, in which SHR-derived endothelial cell monolayers exhibited a more profound upregulation in response to LPS and cytokines.14 15 The blunted ICAM-1 upregulation in response to LPS is not likely related to alterations in responsiveness to TNF-{alpha} or to the production of this cytokine. Most SHR organs that exhibited a decreased responsiveness to LPS responded to TNF-{alpha}lz in a manner similar to that in WKY tissues. Furthermore, TNF-{alpha} production has been shown to be increased in SHR compared with WKY.44

An explanation for the inconsistent findings between the in vitro and in vivo responses of brain endothelium to LPS is not readily available; however, it may be related to the fact that multiple cell types participate in the LPS response in vivo, which is not easily mimicked in a cell culture system. Nonetheless, our findings of an attenuated upregulation of ICAM-1 in SHR relative to WKY may explain the blunted LECA observed in mesenteric postcapillary venules exposed to acute inflammatory mediators.18 19 20 However, since the LECA elicited by platelet-activating factor and leukotriene B4 occurs so rapidly that it largely involves an interaction between CD11/CD18 on leukocytes with constitutively expressed ICAM-1 on endothelial cells, it remains unclear whether ICAM-1 upregulation is a limiting factor in the recruitment of inflammatory cells after exposure of the vasculature to such stimuli.

Recent studies45 46 have demonstrated that glucocorticoids suppress LPS- and cytokine-induced expression of adhesion molecules, including ICAM-1, on cultured endothelial cells. These observations are potentially important because higher plasma levels of glucocorticoids have been noted in hypertensive rats.47 48 Furthermore, the increased glucocorticoid level has been invoked to explain the blunted P-selectin–dependent leukocyte adhesion response elicited by histamine in SHR, since administration of a glucocorticoid receptor antagonist (RU-486) restored the histamine-induced leukocyte adhesion response to the level observed in WKY.20 To further address this possibility, we examined the influence of RU-486 on LPS-induced ICAM-1 expression. We found that RU-486 had a minimal influence on LPS-induced ICAM-1 expression, suggesting that endogenous glucocorticoids are not a major determinant of the altered ICAM-1 expression observed in SHR. These observations do not exclude the possibility that glucocorticoids may make a more significant contribution to the altered expression of other endothelial cell adhesion molecules (eg, P-selectin) in SHR.


*    Selected Abbreviations and Acronyms
 
ACE = angiotensin-converting enzyme
ICAM = intercellular adhesion molecule
LECA = leukocyte–endothelial cell adhesion
LPS = lipopolysaccharide
mAb = monoclonal antibody
SHR = spontaneously hypertensive rat(s)
TNF-{alpha} = tumor necrosis factor-{alpha}
WKY = Wistar-Kyoto rat(s)


*    Acknowledgments
 
This work was supported by a grant from the National Heart, Lung, and Blood Institute, National Institutes of Health (HL-26441).

Received June 5, 1996; first decision July 18, 1996; first decision August 22, 1996;
*    References
up arrowTop
up arrowAbstract
up arrowIntroduction
up arrowMethods
up arrowResults
up arrowDiscussion
*References
 
1. Cavender DE. Interactions between endothelial cells and the cells of immune system. Int Rev Exp Pathol. 1991;32:57-94.[Medline] [Order article via Infotrieve]

2. Pober JS. Cytokine-mediated activation of vascular endothelium: physiology and pathology. Am J Pathol. 1988;133:426-433.[Abstract]

3. Carlos TM, Harlan JM. Leukocyte-endothelial adhesion molecules. Blood. 1994;84:2068-2101.[Abstract/Free Full Text]

4. Bevilacqua MP. Endothelial-leukocyte adhesion molecules. Annu Rev Immunol. 1993;11:767-804.[Medline] [Order article via Infotrieve]

5. Springer TA. Traffic signals for lymphocyte recirculation and leukocyte emigration: the multistep paradigm. Cell. 1994;76:301-314.[Medline] [Order article via Infotrieve]

6. Diamond MS, Staunton DE, de Fougerolles AR, Stacker SA, Aguilar-Garcia J, Hibbs ML, Springer TA. ICAM-1 (CD54): a counter-receptor for Mac-1 (CD11b/CD18). J Cell Biol. 1990;111:3129-3139.[Abstract/Free Full Text]

7. Duchow J, Marchant A, Delville JP, Schandene L, Goldman M. Upregulation of adhesion molecules induced by broncho-vaxom on phagocytic cells. Int J Immunopharmacol. 1992;14:761-766.[Medline] [Order article via Infotrieve]

8. Myers CL, Wertheimer SJ, Schembri KJ, Parks T, Wallace RW. Induction of ICAM-1 by TNF-alpha, IL-1 beta, and LPS in human endothelial cells after downregulation of PKC. Am J Physiol. 1992;263:C767-C772.[Abstract/Free Full Text]

9. Anderson DC. The role of ß2 integrins and intercellular adhesion molecule type 1 in inflammation. In: Granger DN, Schmid-Schonbein GW, eds. Physiology and Pathophysiology of Leukocyte Adhesion. New York, NY: Oxford University Press; 1995:3-42.

10. Barroso-Aranda J, Schmid-Schonbein GW, Zweifach BW, Engler RL. Granulocytes and the no-reflow phenomenon in irreversible hemorrhage shock. Circ Res. 1988;63:437-447.[Abstract/Free Full Text]

11. Engler RL, Dahlgren MD, Morris DD, Peterson MA, Schmid-Schonbein GW. Role of leukocytes in the response to myocardial ischemia and reflow in dogs. Am J Physiol. 1986;251:H314-H323.[Abstract/Free Full Text]

12. Hernandez LA, Grisham MB, Twohig G, Arfors KE, Harlan JM, Granger DN. Role of neutrophils in ischemia reperfusion-induced microvascular injury. Am J Physiol. 1987;253:H699-H703.[Abstract/Free Full Text]

13. Gerritz RJ. The role of the monocyte in atherogenesis, I: transition of blood-borne monocytes into foam cells in fatty lesions. Am J Pathol. 1981;103:181-190.[Abstract]

14. McCarron RM, Wang L, Siren AL, Spatz M, Hallenbeck JM. Adhesion molecules on normotensive and hypertensive rat brain endothelial cells. Proc Soc Exp Biol Med. 1994;205:257-262.[Medline] [Order article via Infotrieve]

15. McCarron RM, Wang L, Siren AL, Spatz M, Hallenbeck JM. Monocyte adhesion to cerebrovascular endothelial cells derived from hypertensive and normotensive rats. Am J Physiol. 1994;267:H2491-H2497.[Abstract/Free Full Text]

16. Panes J, Kurose I, Rodriguez-Vaca MD, Anderson DC, Miyasaka M, Tso P, Granger DN. Diabetes exacerbates inflammatory responses to ischemia-reperfusion. Circulation. 1996;93:161-167.[Abstract/Free Full Text]

17. Gauthier TW, Scalia R, Murohara T, Guo JP, Lefer AM. Nitric oxide protects against leukocyte-endothelium interactions in the early stages of hypercholesterolemia. Arterioscler Thromb Vasc Biol. 1995;15:1652-1659.[Abstract/Free Full Text]

18. Arndt H, Smith CW, Granger DN. Leukocyte-endothelial cell adhesion in spontaneously hypertensive and normotensive rats. Hypertension. 1993;21:667-673.[Abstract/Free Full Text]

19. Schmid-Schonbein GW, Suematsu M, DeLano FA, Shen K, Zweifach BW. Functional alteration of microvascular endothelial cells and its correlation to leukocyte behavior in spontaneously hypertensive rats. FASEB J. 1993;7:A901. Abstract.

20. Suzuki H, Schmid-Schonbein GW, Suematsu M, DeLano FA, Forrest MJ, Miyasaka M, Zweifach BW. Impaired leukocyte-endothelial cell interaction in spontaneously hypertensive rats. Hypertension. 1994;24:719-727.[Abstract/Free Full Text]

21. Panes J, Perry MA, Anderson DC, Manning A, Leone B, Cepinskas G, Rosenbloom CL, Miyasaka M, Kvietys PR, Granger DN. Regional differences in constitutive and induced ICAM-1 expression in vivo. Am J Physiol. 1995;269:H1955-H1964.[Abstract/Free Full Text]

22. Chen IIH, Prewitt RL, Dowell RF. Microvascular rarefaction in spontaneously hypertensive rat cremaster muscle. Am J Physiol. 1981;241:H306-H310.

23. Hutchins PM, Darnell AE. Observations of a decreased number of small arterioles in spontaneously hypertensive rats. Circ Res. 1974;34-35(suppl I):I-161-I-165.

24. Korthuis RJ, Kerr CR, Townsley MI, Taylor AE. Microvascular pressure, surface area, and permeability in isolated hindquarters of SHR. Am J Physiol. 1985;249:H498-H504.

25. Tamatani T, Miyasaka M. Identification of monoclonal antibodies reactive with the rat homolog of ICAM-1, and evidence for a differential involvement of ICAM-1 in the adherence of resting versus activated lymphocytes to high endothelial cells. Int Immunol. 1990;2:165-171.[Abstract/Free Full Text]

26. Ma L, Raycroft L, Asa D, Anderson DC, Geng JB. A sialoglycoprotein from human leukocytes functions as a ligand for P-selectin. J Biol Chem. 1994;269:27739-27746.[Abstract/Free Full Text]

27. Mulligan SM, Varani J, Warren JS, Till GO, Smith CW, Anderson DC, Todd RF, Ward PA. Roles of ß2 integrins of rat neutrophils in complement- and oxygen radical-mediated acute inflammatory injury. J Immunol. 1992;148:1847-1851.[Abstract]

28. Danilov S, Muzykantov VR, Martynov A, Atochina E, Sakharov I, Trakht I, Smirnov V. Lung is a target organ for a monoclonal antibody to angiotensin-converting-enzyme. Lab Invest. 1991;64:118-124.[Medline] [Order article via Infotrieve]

29. Bocci V. Efficient labeling of serum proteins with 131I using chloramine T. Int J Appl Radiat Isot. 1964;15:449-456.[Medline] [Order article via Infotrieve]

30. Fraker PJ, Speck JC. Protein and cell membrane iodination with a sparingly soluble chloramine. Biochem Biophys Res Commun. 1978;80:849-856.[Medline] [Order article via Infotrieve]

31. Panes J, Perry MA, Anderson DC, Muzykantov VR, Carden DL, Miyasaka M, Kvietys PR, Granger DN. Portal hypertension enhances endotoxin-induced intercellular adhesion molecule 1 up-regulation in the rat. Gastroenterology. 1996;110:866-874.[Medline] [Order article via Infotrieve]

32. Morita Y, Miller LS, Rangan U, Kondo S, Clemens MG, Miyasaka M, Yoshizawa T, Bulkley GB. Reactive oxidants mediate tumor necrosis factor {alpha}-induced leukocyte adhesion to rat mesenteric venular endothelium. Am J Physiol. 1995;269:H1833-H1842.[Abstract/Free Full Text]

33. Schmid-Schonbein GW, Seiffge D, DeLano FA, Shen K, Zweifach BW. Leukocyte counts and activation in spontaneously hypertensive and normotensive rats. Hypertension. 1991;17:323-330.[Abstract/Free Full Text]

34. Friedman GD, Selby JV, Quesenberry CP. The leukocyte count: a predictor of hypertension. J Clin Epidemiol. 1990;43:907-911.[Medline] [Order article via Infotrieve]

35. Shen K, DeLano FA, Zweifach BW, Schmid-Schonbein GW. Circulating leukocyte counts, activation and degranulation in Dahl hypertensive rats. Circ Res. 1995;76:276-283.[Abstract/Free Full Text]

36. Ananchenko VG, Kuznetsov SV, Vakolyuk RM, Vakolyuk VS, Strizhova NV, Malashenkova IK, Kim IS. Neutrophil and lymphocyte activity in essential hypertension. Sovetskaia Meditsina. 1988;7:32-35.

37. Ananchenko VG, Vakolyuk RM, Kuznetsov SV, Malashenkova IK, Streitsova RV, Strizhova NV, Malashenkova IK. The NBT test in hypertensive patients. Sovetskaia Meditsina. 1986;10:3-5.

38. Schmid-Schonbein GW, Skalak R, Simon SI, Engler RL. The interaction between leukocytes and endothelium in-vivo. Proc N Y Acad Sci. 1988;516:348-361.

39. Keelan ETM, Licence ST, Peters AM, Binns RM, Haskard DO. Characterization of E-selectin in vivo using a radiolabeled monoclonal antibody. Am J Physiol. 1994;266:H279-H290.

40. Hilbert P, Lindpaintner K, Beckmann JS, Serikawa T, Soubrier F, Dubay C, Cartwright P, Degouyon B, Julier C, Takahashi S, Vincent M, Ganten D, Georges M, Lathrop GM. Chromosomal mapping of two genetic loci associated with blood pressure regulation in hereditary hypertensive rats. Nature. 1991;353:521-529.[Medline] [Order article via Infotrieve]

41. Jacob HJ, Lindpaintner K, Lincoln SE, Kusumi K, Bunker RK, Mao YP, Ganten D, Dzau VJ, Lander ES. Genetic mapping of a gene causing hypertension in the stroke-prone spontaneously hypertensive rats. Cell. 1991;67:213-224.[Medline] [Order article via Infotrieve]

42. Fernandez-Alfonso MS, Kreutz R, Zeh K, Liu Y, Ganten D, Paul M. Differential regulation of vascular angiotensin I-converting enzyme in hypertension. Hypertension. 1994;24:280-286.[Abstract/Free Full Text]

43. Michael B, Welsch C, Coquard C, Grima M, Bathelmebs M, Imbs JL. Angiotensin converting enzyme variability in hypertensive and normotensive rats. Hypertension. 1993;21:442-445.[Abstract/Free Full Text]

44. Hallenbeck JM, Dutka AJ, Vogel SN, Heldman E, Doron DA, Feuerstein G. Lipopolysaccharide-induced production of tumor necrosis factor activity in rats with or without risk factors for stroke. Brain Res. 1991;541:115-120.[Medline] [Order article via Infotrieve]

45. Cronstein BN, Kimmel SC, Levin RI, Martiniuk F, Weissmann G. A mechanism for the antiinflammatory effects of corticosteroids: the glucocorticoid receptor regulates leukocyte adhesion to endothelial cell and expression of endothelial-leukocyte adhesion molecule 1 and intercellular adhesion molecule 1. Proc Natl Acad Sci U S A. 1992;89:9991-9995.[Abstract/Free Full Text]

46. Aziz KE, Wakefield D. Modulation of endothelial cell expression of ICAM-1, E-selectin, and VCAM-1 by ß-estradiol, progesterone, and dexamethasone. Cell Immunol. 1996;167:79-85.[Medline] [Order article via Infotrieve]

47. Rapp JP, Dahl LK. 18-hydroxy-decorticosterone secretion in experimental hypertension in rats. Circ Res. 1971;28,29(suppl II):II-153-II-159.

48. Hashimoto K, Makino S, Hirasawa R, Takao T, Sugawara M, Murakami K, Ono K, Ota Z. Abnormalities in the hypothalamo-pituitary-adrenal axis in spontaneously hypertensive rats during development of hypertension. Endocrinology. 1989;125:1161-1167.[Abstract/Free Full Text]




This article has been cited by other articles:


Home page
Biol Res NursHome page
K. C. Insel, S. L. Reminger, and C.-P. Hsiao
White Matter Hyperintensities and Medication Adherence
Biol Res Nurs, October 1, 2008; 10(2): 121 - 127.
[Abstract] [PDF]


Home page
HypertensionHome page
G. E. Callera, A. C. Montezano, R. M. Touyz, T. M.T. Zorn, M. H. C. Carvalho, Z. B. Fortes, D. Nigro, E. L. Schiffrin, and R. C. Tostes
ETA Receptor Mediates Altered Leukocyte-Endothelial Cell Interaction and Adhesion Molecules Expression in DOCA-Salt Rats
Hypertension, April 1, 2004; 43(4): 872 - 879.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
G. J. Blake, N. Rifai, J. E. Buring, and P. M Ridker
Blood Pressure, C-Reactive Protein, and Risk of Future Cardiovascular Events
Circulation, December 16, 2003; 108(24): 2993 - 2999.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
J. Liu, F. Yang, X.-P. Yang, M. Jankowski, and P. J. Pagano
NAD(P)H Oxidase Mediates Angiotensin II-Induced Vascular Macrophage Infiltration and Medial Hypertrophy
Arterioscler Thromb Vasc Biol, May 1, 2003; 23(5): 776 - 782.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
F. Kuwahara, H. Kai, K. Tokuda, H. Niiyama, N. Tahara, K. Kusaba, K. Takemiya, A. Jalalidin, M. Koga, T. Nagata, et al.
Roles of Intercellular Adhesion Molecule-1 in Hypertensive Cardiac Remodeling
Hypertension, March 1, 2003; 41(3): 819 - 823.
[Abstract] [Full Text] [PDF]


Home page
HeartHome page
X-M Wang, Y Li, H-F Li, F Liu, and G-L Jia
Effects of perindopril on soluble intercellular adhesion molecule-1 in patients with congestive heart failure
Heart, October 1, 2002; 88(4): 417 - 417.
[Full Text] [PDF]


Home page
HypertensionHome page
C. U. Chae, R. T. Lee, N. Rifai, and P. M. Ridker
Blood Pressure and Inflammation in Apparently Healthy Men
Hypertension, September 1, 2001; 38(3): 399 - 403.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
A. Kiarash, P. J. Pagano, M. Tayeh, N.-E. Rhaleb, and O. A. Carretero
Upregulated Expression of Rat Heart Intercellular Adhesion Molecule-1 in Angiotensin II- but Not Phenylephrine- Induced Hypertension
Hypertension, January 1, 2001; 37(1): 58 - 65.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Gastrointest. Liver Physiol.Home page
S. Komatsu, R. D. Berg, J. M. Russell, Y. Nimura, and D. N. Granger
Enteric microflora contribute to constitutive ICAM-1 expression on vascular endothelial cells
Am J Physiol Gastrointest Liver Physiol, July 1, 2000; 279(1): G186 - G191.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Heart Circ. Physiol.Home page
R. R. Langley, J. Russell, M. J. Eppihimer, S. J. Alexander, M. Gerritsen, R. D. Specian, and D. N. Granger
Quantification of murine endothelial cell adhesion molecules in solid tumors
Am J Physiol Heart Circ Physiol, September 1, 1999; 277(3): H1156 - H1166.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
I. Kurose, R. Wolf, W. Cerwinka, and D. N. Granger
Microvascular Responses to Ischemia/Reperfusion in Normotensive and Hypertensive Rats
Hypertension, August 1, 1999; 34(2): 212 - 216.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
L. E. P. Rohde, C. H. Hennekens, and P. M. Ridker
Cross-Sectional Study of Soluble Intercellular Adhesion Molecule-1 and Cardiovascular Risk Factors in Apparently Healthy Men
Arterioscler Thromb Vasc Biol, July 1, 1999; 19(7): 1595 - 1599.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
Y. Dorffel, C. Latsch, B. Stuhlmuller, S. Schreiber, S. Scholze, G. R. Burmester, and J. Scholze
Preactivated Peripheral Blood Monocytes in Patients With Essential Hypertension
Hypertension, July 1, 1999; 34(1): 113 - 117.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Gastrointest. Liver Physiol.Home page
M. Casadevall, E. Saperas, J. Panes, A. Salas, D. C. Anderson, J. R. Malagelada, and J. M. Pique
Mechanisms underlying the anti-inflammatory actions of central corticotropin-releasing factor
Am J Physiol Gastrointest Liver Physiol, April 1, 1999; 276(4): G1016 - G1026.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
F. C. Luft, E. Mervaala, D. N. Muller, V. Gross, F. Schmidt, J. K. Park, C. Schmitz, A. Lippoldt, V. Breu, R. Dechend, et al.
Hypertension-Induced End-Organ Damage : A New Transgenic Approach to an Old Problem
Hypertension, January 1, 1999; 33(1): 212 - 218.
[Abstract] [Full Text] [PDF]


Home page
HypertensionHome page
E. M. A. Mervaala, D. N. Muller, J.-K. Park, F. Schmidt, M. Lohn, V. Breu, D. Dragun, D. Ganten, H. Haller, and F. C. Luft
Monocyte Infiltration and Adhesion Molecules in a Rat Model of High Human Renin Hypertension
Hypertension, January 1, 1999; 33(1): 389 - 395.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Gastrointest. Liver Physiol.Home page
Z. Morise, S. Komatsu, J. W. Fuseler, D. N. Granger, M. Perry, A. C. Issekutz, and M. B. Grisham
ICAM-1 and P-selectin expression in a model of NSAID-induced gastropathy
Am J Physiol Gastrointest Liver Physiol, February 1, 1998; 274(2): G246 - G252.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Renal Physiol.Home page
B. Rodriguez-Iturbe, Y. Quiroz, M. Nava, L. Bonet, M. Chavez, J. Herrera-Acosta, R. J. Johnson, and H. A. Pons
Reduction of renal immune cell infiltration results in blood pressure control in genetically hypertensive rats
Am J Physiol Renal Physiol, February 1, 2002; 282(2): F191 - F201.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Komatsu, S.
Right arrow Articles by Granger, D. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Komatsu, S.
Right arrow Articles by Granger, D. N.