1
|
Abstract
Abstract
This is the Fourth article in the Journal's series on major trauma. Chaudry and Bland, leading experts in the field, consider the cellular implications of injury.
Collapse
|
2
|
Choudhry MA, Bland KI, Chaudry IH. Insight into the Mechanism of Gender-specific Response to Trauma-hemorrhage. Intensive Care Med 2007. [DOI: 10.1007/978-0-387-49518-7_78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
3
|
Mayr S, Walz CR, Angele P, Hernandez-Richter T, Chaudry IH, Loehe F, Jauch KW, Angele MK. Castration prevents suppression of MHC class II (Ia) expression on macrophages after trauma-hemorrhage. J Appl Physiol (1985) 2006; 101:448-53. [PMID: 16614359 DOI: 10.1152/japplphysiol.00166.2006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Several studies indicate that cell-mediated immune responses, i.e., macrophage (MΦ) cytokine release capacities, myosin heavy chain (MHC) class II (Ia) expression, etc., are suppressed after trauma-hemorrhage in male mice. Testosterone has been shown to be responsible for the depression of MΦ cytokine responses in males after trauma-hemorrhage. Antigen presentation via MHC class II plays a key role in initiating and maintaining cell-mediated and humoral immune responses. It remains unknown, however, whether testosterone has any effect on MHC class II after trauma-hemorrhage. To study this, male C3H/HeN mice were castrated or sham castrated 2 wk before trauma (midline laparotomy) and hemorrhage (Hem; blood pressure 35 ± 5 mmHg for 90 min and resuscitation) or sham operation. Four hours thereafter, MHC class II (Ia) expression was measured using flow cytometry. The results indicate that MHC class II (Ia) expression on peritoneal and splenic MΦ was significantly suppressed in male mice after trauma-hemorrhage. Prior castration, however, prevented the depression in MHC class II (Ia) expression on peritoneal and splenic MΦ after trauma-hemorrhage. Castration did not affect MHC class II (Ia) expression in MΦ from sham-castrated mice. Thus testosterone depresses MHC class II (Ia) expression on peritoneal and splenic MΦ after trauma-hemorrhage in males. Because MHC class II is necessary for an adequate immune response, our results suggest that depletion of male sex steroids or blockade of androgen receptors using agents such as flutamide might prevent immunosuppression via maintaining MHC class II (Ia) expression after trauma and severe blood loss.
Collapse
|
4
|
Yang S, Hu S, Choudhry MA, Rue LW, Bland KI, Chaudry IH. ANTI-IL-6R-ANTIBODY DOWNREGULATES CARDIAC IL-6 AND IMPROVES CARDIAC FUNCTION FOLLOWING TRAUMA-HEMORRHAGE (T-H). Shock 2006. [DOI: 10.1097/00024382-200606001-00238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
5
|
Wittmann F, Prix N, Mayr S, Angele P, Wichmann MW, van den Engel NK, Hernandez-Richter T, Chaudry IH, Jauch KW, Angele MK. l-Arginine Improves Wound Healing after Trauma-Hemorrhage by Increasing Collagen Synthesis. ACTA ACUST UNITED AC 2005; 59:162-8. [PMID: 16096557 DOI: 10.1097/01.ta.0000171529.06625.a8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Several studies indicate impaired wound healing after trauma and shock. Wound immune cell dysfunction seems to be responsible for altered wound healing after trauma-hemorrhage (T-H). In this respect, administration of the amino acid L-arginine normalized wound immune cell function under those conditions. It remains unknown, however, whether L-arginine improves impaired wound healing after T-H. METHODS To study this, male C3H/HeN mice were subjected to a midline laparotomy (i.e., soft tissue trauma induced), and polyvinyl sponges were implanted subcutaneously at the wound site before hemorrhage (35 +/- 5 mm Hg for 90 minutes) or were subjected to sham operation. During resuscitation, mice received 300 mg/kg body weight L-arginine or saline (vehicle). Seven days thereafter, hydroxyproline (OHP), a metabolite of collagen synthesis, was measured in the wound fluid using high-performance liquid chromatography. Collagen types I and III were determined in the wound by Western blot analysis. In addition, wound breaking strength was measured 10 days after T-H or sham operation. RESULTS The results indicate that OHP was significantly decreased in T-H mice. L-arginine, however, restored depressed OHP in the wound fluid in the T-H animals. Similarly, L-arginine treatment prevented a significant depression of collagen I synthesis after T-H. Collagen III was not significantly affected by T-H or L-arginine. Most important, L-arginine increased maximal wound breaking strength after severe blood loss. Therefore, L-arginine improves wound healing after T-H by increasing collagen synthesis. CONCLUSION Because L-arginine improves wound healing, the results suggest that L-arginine might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications after trauma and severe blood loss.
Collapse
|
6
|
Eisenmenger SJ, Wichmann MW, Angele P, Faist E, Hatz R, Chaudry IH, Jauch KW, Angele MK. Differences in the expression of LPS-receptors are not responsible for the sex-specific immune response after trauma and hemorrhagic shock. Cell Immunol 2005; 230:17-22. [PMID: 15541715 DOI: 10.1016/j.cellimm.2004.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Accepted: 08/13/2004] [Indexed: 10/26/2022]
Abstract
Several studies demonstrated a sex-specific cytokine secretion by macrophages following trauma-hemorrhage (T-H) and incubation with lipopolysaccharide A (LPS). Although LPS is known to act via the receptors CD14 and TLR4 on macrophages, it remains unknown whether differences in LPS receptor expression in males and females may be responsible for the gender-specific LPS induced cytokine response following (T-H). To study this, male and proestrus female mice (C3H/HeN) were subjected to trauma (laparotomy) followed by hemorrhage or sham operation. At 2 h thereafter, SMphi and PMphi were harvested and cultured for 2 h. The expression of CD14 and TLR4 was measured by flow cytometry on unstimulated SMphi and PMphi as well as after LPS stimulation. The results indicate that the expression of CD14 and TLR4 on SMphi and PMphi from female and male mice was similar in sham-operated animals and after (T-H). Incubation of macrophages with LPS did not alter CD14 and TLR4 expression in the study groups. Thus, the sex specific LPS induced cytokine secretion after (T-H) is not caused by differences in LPS receptor expression on Mphi of male and female mice.
Collapse
|
7
|
Schwacha MG, Alexander M, Chaudry IH, Daniels T. DIFFERENTIAL ROLE OF p38 AND ERK 1/2 MAP KINASES IN THE INDUCTION OF MACROPHAGE HYPERACTIVITY FOLLOWING BURN TRAUMA. Shock 2003. [DOI: 10.1097/00024382-200306001-00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
Yang S, Zheng R, Bland KI, Chaudry IH. 17β-ESTRADIOL IMPROVES CARDIAC FUNCTION AND REDUCES CARDIAC MYOCYTES IL-6 PRODUCTION FOLLOWING TRAUMA-HEMORRHAGIC SHOCK. Shock 2003. [DOI: 10.1097/00024382-200306001-00176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
9
|
Samy TSA, Rue LW, Chaudry IH. Critical Role of Hormones in Traumatic Injury and Outcome. Intensive Care Med 2003. [DOI: 10.1007/978-1-4757-5548-0_79] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
|
10
|
Matsuki Y, Li L, Hsu HC, Yang PA, Zheng R, Edwards CK, Chaudry IH, Zhang HG, Mountz JD. Soluble Fas gene therapy protects against Fas-mediated apoptosis of hepatocytes but not the lethal effects of Fas-induced TNF-alpha production by Kupffer cells. Cell Death Differ 2002; 9:626-35. [PMID: 12032671 DOI: 10.1038/sj.cdd.4401016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2001] [Revised: 11/06/2001] [Accepted: 12/06/2001] [Indexed: 02/01/2023] Open
Abstract
The elevation of soluble Fas (sFas) in the sera of patients with liver disease suggests a role for sFas in the disease process; whether it is protective or not is controversial. To determine the effects of sFas on Fas-induced liver apoptosis, we manipulated mice to produce sFas by transfecting them in vivo with different amounts of an adenovirus that produces mouse sFas driven by the CMV promoter (AdsFas). Fas-mediated apoptosis was induced by administration of anti-mouse Fas (Jo2; 10 microg/mouse) one week later. The administration of AdsFas (10(3), 10(7), or 10(9) pfu/mouse), which was associated with only minimal side-effects, resulted in a significant reduction in the liver transaminase levels and mortality of the mice on challenge with Jo2, as compared to control mice treated with AdLacZ. However, the protective effect of AdsFas was not complete. The possibility that Jo2-induction of TNF-alpha in the Kupffer cells of the liver contributes to the pathology was therefore tested. Although administration of soluble TNF receptor (sTNFRI) alone did not protect the mice from the lethal effects of Jo2, administration of sTNFRI (200 microg/mouse) after infection with AdsFas (10(9) pfu/mouse) resulted in 100% survival of the mice on challenge with Jo2. To confirm that the production of TNF-alpha by Kupffer cells produce the lethal effects of Jo2 that remained after treatment with AdsFas, these cells were selectively ablated by treatment of the mice with gadolinium chloride prior to challenge with Jo2. This treatment greatly reduced early mortality and hepatocellular damage as well as TNF-alpha production 6 h after injection of Jo2. These results indicate that: (1) AdsFas prevents Jo2-induced apoptosis of hepatocytes; (2) In addition to mediating Fas-mediated apoptosis of hepatocytes, Jo2 can separately induce TNF-alpha production by Kupffer cells resulting in early mortality, and (3) Optimal protection from Jo2-induced mortality can be achieved by protection of liver cells by pretreatment with both AdsFas and sTNFRI.
Collapse
|
11
|
Schwacha MG, Chaudry IH. DOES β2 INTEGRIN (C11b/CD18) SIGNALING REGULATE MACROPHAGE INFLAMMATORY MEDIATOR PRODUCTION POST-INJURY? Shock 2002. [DOI: 10.1097/00024382-200206001-00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
12
|
Knöferl MW, Diodato MD, Schwacha MG, Cioffi WG, Bland KI, Chaudry IH. Cyclooxygenase-2-mediated regulation of Kupffer cell interleukin-6 production following trauma-hemorrhage and subsequent sepsis. Shock 2001; 16:479-83. [PMID: 11770048 DOI: 10.1097/00024382-200116060-00013] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Studies indicate that trauma-hemorrhage results in activation of Kupffer cells to release inflammatory mediators and it leads to immunosuppression and increased susceptibility to subsequent sepsis. The cyclooxygenase (COX) product prostaglandin (PG) E2 appears to be central to this process, however, non-selective inhibition of COX activity with non-steroidal anti-inflammatory agents that block both the constitutive (COX-1) and inducible (COX-2) isoforms of cyclooxygenase has not yielded promising results in trauma patients. Nonetheless, it remains unknown whether selective inhibition of COX-2 activity has any salutary effect following trauma-hemorrhage and subsequent induction of sepsis. To study this, male C3H/HeN mice were subjected to laparotomy (i.e., soft-tissue trauma) and hemorrhagic shock (35 +/- 5 mmHg for 90 min, then resuscitated) or to sham operation. Twenty-four hours later, the mice were subjected to sepsis by cecal ligation and puncture (CLP) or to sham CLP. The mice were treated with the COX-2 inhibitor NS-398 (10 mg/kg body weight, intraperitoneally) or vehicle immediately after trauma-hemorrhage or sham operation, 12 h thereafter, and following CLP or sham CLP. At 5 h after CLP, plasma PGE2, Interleukin-(IL) 6, and TNF-alpha levels were determined along with Kupffer cell IL-6 and TNF-alpha production in vitro. NS-398 treatment markedly suppressed the elevation in plasma PGE2 levels following CLP. The increase in plasma IL-6 levels after CLP were also significantly attenuated by NS-398 treatment. In vitro Kupffer cell IL-6 production after CLP was significantly reduced by in vivo NS-398 treatment. However, NS-398 had no effect on TNF-alpha levels, in vivo and in vitro. These findings indicate that activation of COX-2 following trauma-hemorrhage and subsequent sepsis up-regulates Kupffer cell IL-6 production. Thus, selective inhibition of COX-2 activity may reduce the deleterious consequences of sepsis under such conditions.
Collapse
|
13
|
Angele MK, Knöferl MW, Ayala A, Bland KI, Chaudry IH. Testosterone and estrogen differently effect Th1 and Th2 cytokine release following trauma-haemorrhage. Cytokine 2001; 16:22-30. [PMID: 11669583 DOI: 10.1006/cyto.2001.0945] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The object of the study was to determine whether male and female sex steroids produce divergent effects on Th1 and Th2 cytokine release following trauma-haemorrhage. Recent studies indicate that androgens are responsible for the depressed splenocyte Th1 cytokine release in males following trauma-haemorrhage. In contrast, female mice maintain their Th1 cytokine release capacity following trauma-haemorrhage. Nonetheless, the effect of male and female sex steroids on Th1 and Th2 cytokine release following trauma-haemorrhage remains unknown. Male C3H/HeN mice were castrated and treated with pellets containing either vehicle, 5alpha-dihydrotestosterone (DHT), 17beta-estradiol (estradiol), or a combination of both steroid hormones, for 14 days prior to soft-tissue trauma (i.e. laparotomy) and haemorrhagic shock (35+/-5 mmHg for 90 min followed by adequate fluid resuscitation) or sham operation. Untreated male and female mice, as well as DHT treated female mice, served as control groups. Twenty-four hours later the animals were sacrificed, plasma obtained and splenocytes harvested. Plasma DHT and estradiol levels in treated animals were comparable with intact male and female mice, respectively. A significant depression of splenocyte Th1 cytokines, i.e. IL-2, IFN-gamma, was observed in DHT treated castrated animals, DHT treated females, and untreated males following trauma-haemorrhage, as opposed to maintained Th1 cytokine release in estradiol treated and estradiol/DHT treated castrated animals and females. The release of the anti-inflammatory cytokine IL-10 was markedly increased in DHT treated mice and males subjected to trauma-haemorrhage compared to shams, but decreased in estrogen treated mice and females under such conditions. These results suggest that male and female sex steroids differentially affect the release of Th1 and Th2 cytokines following trauma-haemorrhage and should be further studied for their potential to modulate splenocyte function in trauma victims.
Collapse
|
14
|
Ba ZF, Wang P, Koo DJ, Ornan DA, Bland KI, Chaudry IH. Attenuation of vascular endothelial dysfunction by testosterone receptor blockade after trauma and hemorrhagic shock. ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 2001; 136:1158-63. [PMID: 11585509 DOI: 10.1001/archsurg.136.10.1158] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
HYPOTHESIS The salutary effects of the testosterone receptor antagonist flutamide on the depressed immune and cardiovascular functions after hemorrhage and resuscitation are related to improved endothelial cell function, which can subsequently lead to an increase in organ blood flow, oxygen delivery, and tissue oxygen consumption. DESIGN, INTERVENTIONS, AND MAIN OUTCOME MEASURES Male adult rats underwent a 5-cm midline laparotomy (ie, trauma) and were bled to and maintained at a mean systemic arterial pressure of 40 mm Hg until 40% maximal blood-out volume was returned in the form of Ringer lactate). The animals were then resuscitated with 4 times the total volume of shed blood with Ringer lactate for 60 minutes. Flutamide (25 mg/kg) or an equivalent volume of the vehicle propanediol was injected subcutaneously 15 minutes before the end of resuscitation. At 20 hours after resuscitation, aortic rings (approximately 2.5 mm in length) were isolated and mounted in an organ chamber. Dose responses for an endothelium-dependent vasodilator (acetylcholine chloride) and endothelium-independent vasodilator (nitroglycerine) were determined. Organ blood flow was measured using strontium 85-labeled microspheres. Total hemoglobin and oxygen content in the femoral artery and portal, hepatic, and renal veins were determined. Oxygen delivery and consumption in liver, small intestine, and kidneys were calculated. RESULTS Administration of flutamide after trauma-hemorrhage attenuated the depressed endothelial function. Furthermore, flutamide treatment restored the reduced blood flow and oxygen delivery and consumption in all organs tested after trauma-hemorrhage and resuscitation. CONCLUSION Flutamide appears to be a useful adjunct for improving vascular endothelial function and regional hemodynamics after trauma-hemorrhage and resuscitation.
Collapse
|
15
|
Schwacha MG, Schneider CP, Bland KI, Chaudry IH. Resistance of macrophages to the suppressive effect of interleukin-10 following thermal injury. Am J Physiol Cell Physiol 2001; 281:C1180-7. [PMID: 11546654 DOI: 10.1152/ajpcell.2001.281.4.c1180] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The activation of a macrophage (Mphi)-dependent proinflammatory cascade following thermal injury plays an important role in the development of immunosuppression and increased susceptibility to subsequent sepsis in burn patients. In contrast, although interleukin (IL)-10, an anti-inflammatory cytokine that can downregulate M phi activity, has also been implicated in postburn immune dysfunction, its role in the regulation of M phi function postburn remains unclear. To study this, C57BL/6 female mice were subjected to a 25% total body surface area third-degree scald burn, and splenic Mphis were isolated 7 days later. Lipopolysaccharide (LPS)-stimulated IL-10, IL-6, tumor necrosis factor (TNF)-alpha, and nitric oxide (NO) production were significantly increased in the burn group compared with shams. Blockade of endogenous IL-10 activity enhanced IL-6 and TNF-alpha release, but not NO release, in both groups. The addition of exogenous IL-10 to the M phi cultures dose dependently suppressed production of these inflammatory mediators in both groups. The timing of IL-10 addition to the cultures in relation to LPS stimulation, however, was critical. The suppressive effect of exogenous IL-10 was attenuated in both groups when the cells were exposed to IL-10 at 4-6 h after LPS stimulation; however, Mphis from injured mice were significantly better able to maintain inflammatory mediator-productive capacity. The resistance of Mphis from injured mice to IL-10-mediated suppression correlated with decreased IL-10 receptor (IL-10R) expression and increased CD11b expression. These findings suggest that Mphis, following thermal injury, display resistance to suppression by IL-10 due in part to downregulation of IL-10R expression.
Collapse
|
16
|
Knöferl MW, Jarrar D, Angele MK, Ayala A, Schwacha MG, Bland KI, Chaudry IH. 17 beta-Estradiol normalizes immune responses in ovariectomized females after trauma-hemorrhage. Am J Physiol Cell Physiol 2001; 281:C1131-8. [PMID: 11546648 DOI: 10.1152/ajpcell.2001.281.4.c1131] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies indicate that immune responses in proestrus females are maintained after trauma-hemorrhage but markedly depressed in ovariectomized females under such conditions. The current study tested the hypothesis that the decreased estrogen levels after ovariectomy are responsible for this immune depression. To study this hypothesis, ovariectomized female CBA/J mice were subjected to laparotomy (i.e., soft tissue trauma) and hemorrhagic shock (35 +/- 5 mmHg for 90 min, then resuscitated) or sham operation. The mice received either 17 beta-estradiol (E2; 100 microg/25 g body wt) or vehicle subcutaneously during resuscitation. Immune cells were isolated 24 h thereafter. Splenocyte proliferation and interferon-gamma, interleukin (IL)-2, and IL-3 release were significantly depressed after trauma-hemorrhage in vehicle-treated mice, whereas these functions were maintained in E2-treated mice. Peritoneal macrophage IL-1 beta and IL-6 release and splenic macrophage IL-6 and IL-12 release were also significantly depressed in vehicle-treated mice after trauma-hemorrhage, and release of these cytokines was restored by E2 treatment. In summary our findings indicate that the depressed splenic and peritoneal immune responses after trauma-hemorrhage can be normalized by a single dose of E2. Thus estrogen appears to be the causative factor in the maintenance of immunocompetence in females after trauma-hemorrhage, and its administration to ovariectomized or postmenopausal females should be helpful in preventing immune depression under such conditions.
Collapse
|
17
|
Yang S, Zhou M, Chaudry IH, Wang P. Norepinephrine-induced hepatocellular dysfunction in early sepsis is mediated by activation of alpha2-adrenoceptors. Am J Physiol Gastrointest Liver Physiol 2001; 281:G1014-21. [PMID: 11557522 DOI: 10.1152/ajpgi.2001.281.4.g1014] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gut-derived norepinephrine (NE) has been shown to play a critical role in producing hepatocellular dysfunction in early sepsis, but it is not known whether alpha2-adrenoceptor activation mediates this dysfunction. We infused normal male adult rats with NE, NE plus the specific alpha2-adrenergic antagonist rauwolscine (RW), or vehicle (normal saline) for 2 h. Hepatocellular function was determined by in vivo indocyanine green (ICG) clearance. An isolated perfused liver preparation was also used to assess hepatocellular function by in vitro ICG clearance; NE alone or with RW was added to the perfusate. Rats were subjected to sepsis by cecal ligation and puncture (CLP). At 1 h after CLP, RW was infused for 15 min. At 5 h after CLP, we measured hepatocellular function and serum tumor necrosis factor-alpha (TNF-alpha) levels. Intraportal NE infusion in normal rats produced hepatocellular dysfunction, which was prevented by RW and NE infusion. This is confirmed by findings with the isolated perfused liver preparation. RW administration in early sepsis maintained hepatocellular function and downregulated TNF-alpha production at 5 h after CLP. These results suggest that NE-induced hepatocellular dysfunction in early sepsis is mediated by alpha2-adrenoceptor activation, which appears to upregulate TNF-alpha production. Modulation of hepatic responsiveness to NE by alpha2-adrenergic antagonists should provide a novel approach for maintaining cell and organ functions during sepsis.
Collapse
|
18
|
Yang S, Zhou M, Chaudry IH, Wang P. The role of lipopolysaccharide in stimulating adrenomedullin production during polymicrobial sepsis. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1537:167-74. [PMID: 11566260 DOI: 10.1016/s0925-4439(01)00069-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Previous studies have shown that adrenomedullin (AM), a potent vasodilatory peptide, is upregulated during sepsis. However, it remains unknown whether the increased AM observed under such conditions is solely due to the elevated levels of circulating lipopolysaccharide (LPS). To determine this, an Alzet micro-osmotic pump, containing a low dose of Escherichia coli LPS or vehicle (sterile normal saline), was implanted in the peritoneal cavity of the normal male adult rat. At 10 h after the pump implantation, samples of blood and small intestine were harvested for the determination of AM by radioimmunoassay. In additional groups, rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). LPS binding agent polymyxin B was administrated intramuscularly at 1 h prior to as well as 5 h after the onset of sepsis. At 10 h after CLP or sham-operation, blood and intestinal samples were harvested and levels of AM were then determined. Plasma levels of LPS were also measured by Limulus amebocyte lysate assay. The results indicate that administration of a low dose of LPS via the peritoneal cavity in normal animals (which did not significantly alter cardiac output, blood pressure or heart rate) markedly increased plasma and intestinal levels of AM. In addition, plasma and tissue levels of AM increased significantly at 10 h after CLP. Administration of polymyxin B, however, attenuated the increase in AM levels under such conditions. Similarly, the increased plasma levels of LPS was significantly reduced by polymyxin B during sepsis. These results, taken together, suggest that the upregulated AM observed during polymicrobial sepsis is at least in part due to the increase in circulating levels of endotoxin.
Collapse
|
19
|
Song GY, Chung CS, Chaudry IH, Ayala A. MAPK p38 antagonism as a novel method of inhibiting lymphoid immune suppression in polymicrobial sepsis. Am J Physiol Cell Physiol 2001; 281:C662-9. [PMID: 11443065 DOI: 10.1152/ajpcell.2001.281.2.c662] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although studies indicate that a shift from a Th1 to a Th2 response contributes to a marked suppression of cell-mediated immunity during sepsis, the mechanism by which this occurs remains unknown. Given that the mitogen-activated protein kinase (MAPK) p38 plays a critical role in the activation and function of immune cells, the aim of this study was to determine the contribution of MAPK p38 activation to the immune dysfunction seen in polymicrobial sepsis. To study this, polymicrobial sepsis was induced in C3H/HeN male mice by cecal ligation and puncture (CLP). Splenic lymphocytes and purified T cells were harvested 24 h post-CLP, pretreated with the specific MAPK p38 inhibitor SB-203580, and then stimulated with a monoclonal antibody against the T cell marker CD3. The results indicate that interleukin (IL)-2 release is markedly depressed while the release of the immunosuppressive mediator, IL-10, as well as mRNA levels of IL-10 and IL-4, are augmented after CLP. Inhibition of MAPK p38 suppressed in vitro IL-10 levels as well as IL-10 and IL-4 gene expression while restoring the release of IL-2. To determine whether these in vitro findings could be translated to an in vivo setting, mice were given 100 mg of SB-203580/kg body wt or saline vehicle (intraperitoneal) at 12 h post-CLP. Examination of ex vivo lymphocyte responsiveness indicated that, as with the in vitro finding, septic mouse Th1 responsiveness was restored. In light of our recent finding that delayed in vivo SB-203580 treatment also improved survival after CLP, we believe that these results not only illustrate the role of MAPK p38 in the induction of immunosuppressive agents in sepsis but demonstrate that SB-203580 administration after the initial proinflammatory state of sepsis significantly prevents the morbidity from sepsis.
Collapse
|
20
|
Samy TS, Knöferl MW, Zheng R, Schwacha MG, Bland KI, Chaudry IH. Divergent immune responses in male and female mice after trauma-hemorrhage: dimorphic alterations in T lymphocyte steroidogenic enzyme activities. Endocrinology 2001; 142:3519-29. [PMID: 11459798 DOI: 10.1210/endo.142.8.8322] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immune responses are suppressed in males, but not in proestrous females, after trauma-hemorrhage. Testosterone and 17beta-estradiol appear to be responsible for divergent immune effects. There is considerable evidence to suggest sex steroid hormone involvement in immune functions. As formation of active steroid depends on the activity of androgen- and estrogen-synthesizing enzymes, expression and activity of 5alpha-reductase, aromatase, and 3beta- and 17beta- hydroxysteroid dehydrogenases were determined in spleen and T lymphocytes of male and proestrous female mice after trauma-hemorrhage. All of the enzymes were present in spleen, specifically in T lymphocytes. 5alpha-Reductase expression and activity increased in male T lymphocytes, whereas aromatase activity, but not expression, increased in female T lymphocytes. Increased 5alpha-reductase activity in male T lymphocytes is immunosuppressive because of increased 5alpha-dihydrotestosterone synthesis, whereas in females increased aromatase activity triggering 17beta-estradiol synthesis is immunoprotective. This study also demonstrates the importance of 17beta-hydroxysteroid dehydrogenase oxidative and reductive functions. The immunoprotection of proestrous females is associated with enhanced reductase function of the enzyme. In males, decreased expression of oxidative isomer type IV, which impairs catabolism of 5alpha-dihydrotestosterone, probably augments immunosuppression. This study provides evidence for the involvement of intracrine sex steroid synthesis in gender dimorphic immune responses after trauma-hemorrhage.
Collapse
|
21
|
Zhou M, Chaudry IH, Wang P. The small intestine is an important source of adrenomedullin release during polymicrobial sepsis. Am J Physiol Regul Integr Comp Physiol 2001; 281:R654-60. [PMID: 11448871 DOI: 10.1152/ajpregu.2001.281.2.r654] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adrenomedullin (AM), a potent vasodilatory peptide, has recently been reported to be involved in the altered cardiovascular responses under various pathophysiological conditions. Although the increase in plasma AM levels is associated with upregulation of AM gene expression in various tissues, it remains unknown whether the gut is an important source of AM release under such conditions. To determine this, adult male rats were subjected to sepsis by cecal ligation and puncture (CLP) followed by fluid resuscitation. Systemic and portal blood samples were collected simultaneously at 10 and 20 h after CLP or sham operation. A portion of the jejunum was also harvested. Plasma and tissue levels of AM were then determined by RIA. The localization of AM in the intestinal tissue was examined using immunohistochemistry. In an additional group of normal rats, synthetic rat AM (8.5 microg/kg body wt) was infused for 15 min at a constant rate via the portal vein (which produces a similar level of AM as observed during sepsis). Cardiac output, stroke volume, total peripheral resistance, and microvascular blood flow in various organs were determined before and 30 min after AM administration. The results indicate that AM levels in portal blood were significantly higher than in systemic blood at 10 and 20 h after CLP. Intestinal AM was also markedly elevated. Immunohistochemical visualization shows that AM immunostainings were localized in the mucosa, submucosa, and intestinal nerve fibers, and they were increased at 10-20 h post-CLP. Because AM-immunopositive nerve fibers increase in the gut during sepsis, a nerve pathway may be involved in the regulation of vascular reactivity by this peptide. Moreover, intraportal administration of AM increased cardiac output, stroke volume, and microvascular blood flow in the liver, kidney, small intestine, and spleen. In contrast, total peripheral resistance was significantly reduced. Thus the gut plays an important role in increasing the levels of circulating AM during the progression of sepsis. Gut-derived AM appears to be a major factor in initiating the hyperdynamic response after the onset of sepsis.
Collapse
|
22
|
Chung CS, Yang S, Song GY, Lomas J, Wang P, Simms HH, Chaudry IH, Ayala A. Inhibition of Fas signaling prevents hepatic injury and improves organ blood flow during sepsis. Surgery 2001; 130:339-45. [PMID: 11490369 DOI: 10.1067/msy.2001.116540] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Fas/Fas ligand (FasL) system is one of the major pathways triggering apoptosis that has been shown to play an important role in development and pathogenesis of various diseases including liver and gastrointestinal diseases. Studies indicate that FasL deficiency provides a survival advantage in mice subjected to polymicrobial sepsis. However, the extent to which Fas/FasL contributes to organ injury during sepsis is unclear. Thus, the aim of this study was to determine whether in vivo administration of a Fas-signaling inhibitor during sepsis preserves organ function. METHODS Male adult C3H/HeN mice were subjected to cecal ligation and puncture (CLP) or sham CLP (sham). Twelve hours after CLP, mice received either Fas-receptor fusion protein (FasFP) (200 microg/kg body weight) or the saline vehicle. Twenty-four hours after the onset of sepsis, cardiac output and organ blood flow were measured with radioactive microspheres. Plasma levels of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were assessed as indexes of liver damage. Changes in systemic cytokines were measured by enzyme-linked immunosorbent assay. RESULTS. The data indicate that although cardiac output and organ blood flow in the liver, intestine, kidneys, spleen, and heart decreased markedly at 24 hours after CLP, treatment with FasFP maintained the measured hemodynamic parameters and improved hepatic, intestinal, and heart blood flow (P <.05) and partially restored spleen and renal blood flow. Moreover, FasFP treatment markedly attenuated the systemic rise in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and interleukin 10 (P <.05). CONCLUSIONS These results not only indicate that there is a role for Fas/FasL-mediated processes in the induction of organ injury but suggest that inhibition of Fas/FasL pathway may represent a novel therapeutic modality for maintaining organ perfusion and preventing liver injury during sepsis.
Collapse
|
23
|
Zhou M, Yang S, Koo DJ, Ornan DA, Chaudry IH, Wang P. The role of Kupffer cell alpha(2)-adrenoceptors in norepinephrine-induced TNF-alpha production. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1537:49-57. [PMID: 11476962 DOI: 10.1016/s0925-4439(01)00055-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Although previous studies have demonstrated that plasma levels of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) increase during early sepsis, the precise mechanism responsible for its upregulation remains to be elucidated. Since recent studies have shown that the gut is an important source of norepinephrine (NE) release during early sepsis and enterectomy prior to the onset of sepsis attenuates TNF-alpha production, we hypothesized that gut-derived NE plays a major role in upregulating TNF-alpha via the activation of alpha(2)-adrenoceptors on Kupffer cells. To confirm that NE increases TNF-alpha synthesis and release, Kupffer cells were isolated from normal rats and incubated with NE (20 or 50 nM) or another alpha(2)-adrenergic agonist clonidine (50 nM) without addition of Escherichia coli endotoxin. Supernatant levels of TNF-alpha were then measured. In additional animals, intraportal infusion of NE (20 microM) with or without the specific alpha(2)-adrenergic antagonist yohimbine (1 mM) at a rate of 13 microl/min was carried out for 2 h. Plasma and Kupffer cell levels of TNF-alpha were assayed thereafter. Moreover, the effects of NE and yohimbine on TNF-alpha production was further examined using an isolated perfused liver preparation. The results indicate that both NE and clonidine increased TNF-alpha release by approximately 4-7-fold in the isolated cultured Kupffer cells. Similarly, intraportal infusion of NE in vivo or in isolated livers increased TNF-alpha synthesis and release which was inhibited by co-infusion of yohimbine. Furthermore, the increased cellular levels of TNF-alpha in Kupffer cells after in vivo administration of NE was also blocked by yohimbine. These results, taken together, suggest that gut-derived NE upregulates TNF-alpha production in Kupffer cells through an alpha(2)-adrenergic pathway, which appears to be responsible at least in part for the increased levels of circulating TNF-alpha observed during early sepsis as well as other pathophysiologic conditions such as trauma, hemorrhagic shock, or gut ischemia/reperfusion.
Collapse
|
24
|
Koo DJ, Jackman D, Chaudry IH, Wang P. Adrenal insufficiency during the late stage of polymicrobial sepsis. Crit Care Med 2001; 29:618-22. [PMID: 11373430 DOI: 10.1097/00003246-200103000-00026] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Although studies have indicated that adrenal insufficiency occurs after severe trauma and hemorrhagic shock, it remains controversial whether adrenal function is depressed during the late stage of polymicrobial sepsis. DESIGN Prospective, controlled animal study. SETTING A university research laboratory. SUBJECTS Male rats (275-325 g) were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP) or sham operation followed by the administration of normal saline solution. MEASUREMENTS AND MAIN RESULTS Systemic blood samples were taken at 20 hrs after CLP (i.e., a late stage of sepsis) or sham operation to measure plasma levels of corticosterone and corticotropin as well as adrenal contents of corticosterone. Additional groups of animals were utilized to examine corticotropin-stimulated plasma corticosterone release as well as adrenal levels of cyclic adenosine monophosphate (cAMP, the second messenger of corticotropin action). The results indicate that despite a 75% (p < .05) higher concentration in plasma corticotropin at 20 hrs after the onset of sepsis, plasma corticosterone levels were similar to those in sham-operated animals. In addition, adrenal contents of corticosterone were reduced by 42% (p < .05) in septic animals. Moreover, the plasma corticosterone and adrenal cAMP responses to corticotropin were reduced by 53% and 27% (p < .05), respectively, at 20 hrs after CLP. CONCLUSIONS These findings suggest that, despite high plasma levels of endogenous corticotropin, adrenal dysfunction, as indicated by the reduction of corticotropin-induced plasma corticosterone release and adrenal contents of cAMP as well as the decreased adrenal levels of corticosterone, occurs during the late stage of polymicrobial sepsis. Therefore, the recognition of adrenal insufficiency and interventions to improve adrenal responsiveness may be beneficial in improving the outcome during late sepsis.
Collapse
|
25
|
Yang S, Koo DJ, Chaudry IH, Wang P. Glycine attenuates hepatocellular depression during early sepsis and reduces sepsis-induced mortality. Crit Care Med 2001; 29:1201-6. [PMID: 11395604 DOI: 10.1097/00003246-200106000-00024] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine whether administration of glycine, a nonessential amino acid, early after the onset of polymicrobial sepsis has any beneficial effects on hepatocellular function and the survivability of septic animals and, if so, whether the beneficial effects of glycine are associated with down-regulation of proinflammatory cytokine tumor necrosis factor-alpha production. DESIGN Prospective, controlled, and randomized animal study. SETTING A university research laboratory. SUBJECTS Male adult rats were subjected to polymicrobial sepsis by cecal ligation and puncture or sham operation followed by the administration of normal saline solution. MEASUREMENTS AND MAIN RESULTS At 1 hr after cecal ligation and puncture, glycine (0.6 mmol/kg) or vehicle (normal saline solution) was administered intravenously over 15 mins. At 5 hrs after cecal ligation and puncture (i.e., early stage of sepsis), hepatocellular function (i.e., the maximal velocity and efficiency of in vivo indocyanine green clearance) was determined and hepatocyte injury was assessed by measuring plasma concentrations of alpha-gluthathione S-transferase. Serum tumor necrosis factor-alpha was measured by enzyme-linked immunosorbent assay. In additional animals, the necrotic cecum was excised at 20 hrs after cecal ligation and puncture, the peritoneal cavity was irrigated with saline, and the midline incision was closed in layers. Mortality was monitored for 10 days thereafter. The results indicate that hepatocellular function was depressed in the early stage of sepsis (i.e., 5 hrs after cecal ligation and puncture) as indicated by significant decreases in both maximal velocity and transport efficiency of in vivo indocyanine green clearance. Plasma concentrations of alpha-gluthathione S-transferase and tumor necrosis factor-alpha were elevated significantly at that interval after cecal ligation and puncture. Administration of glycine 1 hr after cecal ligation and puncture, however, increased maximal velocity and maximal efficiency by 60% and 101% (p <.05), respectively. Glycine administration in septic animals decreased alpha-gluthathione S-transferase and tumor necrosis factor-alpha by 43% and 80% (p <.05). In addition, glycine treatment decreased the mortality rate from 50% to 0% (p <.05) at 10 days after cecal ligation and puncture and cecal excision. CONCLUSIONS It appears that the beneficial effect of glycine on hepatocyte function and integrity in sepsis may be mediated via down-regulation of tumor necrosis factor-alpha. Because administration of glycine attenuated hepatocellular depression and injury during early sepsis and decreased sepsis-induced mortality rates, this amino acid appears to be a useful adjunct for maintaining cellular functions and preventing lethality from polymicrobial sepsis.
Collapse
|