Role of cytosolic vs. mitochondrial Ca2+ accumulation in burn injury-related myocardial inflammation and function

2005 ◽  
Vol 288 (2) ◽  
pp. H744-H751 ◽  
Author(s):  
David L. Maass ◽  
Jean White ◽  
Billy Sanders ◽  
Jureta W. Horton
Keyword(s):  
Room Temperature ◽  
Burn Injury ◽  
Imaging System ◽  
Total Body Surface Area ◽  
Myocardial Inflammation ◽  
Adult Rats ◽  
Burn Trauma ◽  
Fura 2 ◽  
Tnf Α

This study was designed to examine the role of mitochondrial Ca2+ homeostasis in burn-related myocardial inflammation. We hypothesized that mitochondrial Ca2+ is a primary modulator of cardiomyocyte TNF-α, IL-1β, and IL-6 responses to injury and infection. Ventricular myocytes were prepared by Langendorff perfusion of hearts from adult rats subjected to sham burn or burn injury over 40% of total body surface area to produce enzymatic (collagenase) digestion. Isolated cardiomyocytes were suspended in MEM, cell number was determined, and aliquots of myocytes from each experimental group were loaded with fura 2-AM (2 μg/ml) for 1) 45 min at room temperature to measure total cellular Ca2+, 2) 45 min at 30°C followed by incubation at 37°C for 2 h to eliminate cytosolic fluorescence, and 3) 20 min at 37°C in MnCl2 (200 μM)-containing buffer to quench cytosolic fura 2-AM signal. In vitro studies included preparation of myocytes from control hearts and challenge of myocytes with LPS or burn serum (BS), which have been shown to increase cytosolic Ca2+. Additional aliquots of myocytes were challenged with LPS or BS with or without a selective inhibitor of mitochondrial Ca2+, ruthenium red (RR). All cells were examined on a stage-inverted microscope that was interfaced with the InCyt Im2 fluorescence imaging system. Heat treatment or MnCl2 challenge eliminated myocyte cytosolic fluorescence, whereas cells maintained at room temperature retained 95% of their initial fluorescence. Compared with Ca2+ levels measured in sham myocytes, burn trauma increased cytosolic Ca2+ from 90 ± 3 to 293 ± 6 nM ( P < 0.05) and mitochondrial Ca2+ from 24 ± 1 to 75 ± 2 nM ( P < 0.05). LPS (25 μg/5 × 104 cells) or BS (10% by volume) challenge for 18 h increased cardiomyocyte cytosolic and mitochondrial Ca2+ and promoted myocyte secretion of TNF-α, IL-1β, and IL-6. RR pretreatment decreased LPS- and BS-related rise in mitochondrial Ca2+ and cytokine secretion but had no effect on cytosolic Ca2+. BS challenge in perfused control hearts impaired myocardial contraction/relaxation, and RR pretreatment of hearts prevented BS-related myocardial contractile dysfunction. Our data suggest that a rise in mitochondrial Ca2+ is one modulator of myocardial inflammation and dysfunction in injury states such as sepsis and burn trauma.

scholarly journals Hypertonic saline dextran after burn injury decreases inflammatory cytokine responses to subsequent pneumonia-related sepsis

2006 ◽  
Vol 290 (4) ◽  
pp. H1642-H1650 ◽  
Author(s):  
Jureta W. Horton ◽  
David L. Maass ◽  
D. Jean White
Keyword(s):  
Hypertonic Saline ◽  
Burn Injury ◽  
Inflammatory Responses ◽  
Contractile Function ◽  
Total Body Surface Area ◽  
Isotonic Saline ◽  
Ringer Solution ◽  
Myocardial Inflammation ◽  
Adult Rats ◽  
Tnf Α

The present study examined the hypothesis that hypertonic saline dextran (HSD), given after an initial insult, attenuates exaggerated inflammation that occurs with a second insult. Adult rats ( n = 15 per group) were divided into groups 1 (sham burn), 2 [40% total body surface area burn + 4 ml/kg isotonic saline (IS) + 4 ml·kg−1·% burn−1 lactated Ringer solution (LR)], and 3 (burn + 4 ml/kg HSD + LR), all studied 24 h after burns. Groups 4 (sham burn), 5 (burn + IS + LR), and 6 (burns + HSD + LR) received intratracheal (IT) vehicle 7 days after burns; groups 7 (burn + IS + LR) and 8 (burn + HSD + LR) received IT Streptococcus pneumoniae (4 × 106 colony-forming units) 7 days after burn. Groups 4–8 were studied 8 days after burn and 24 h after IT septic challenge. When compared with sham burn, contractile defects occurred 24 h after burn in IS-treated but not HSD-treated burns. Cardiac inflammatory responses (pg/ml TNF-α) were evident with IS (170 ± 10) but not HSD (45 ± 5) treatment vs. sham treatment (80 ± 15). Pneumonia-related sepsis 8 days after IS-treated burns ( group 7) exacerbated TNF-α responses/contractile dysfunction vs. IS-treated burns in the absence of sepsis ( P < 0.05). Sepsis that occurred after HSD-treated burns ( group 8) had less myocyte TNF-α secretion/better contractile function than IS-treated burns given septic challenge ( group 7, P < 0.05). We conclude that an initial burn injury exacerbates myocardial inflammation/dysfunction occurring with a second insult; giving HSD after the initial insult attenuates myocardial inflammation/dysfunction associated with a second hit, suggesting that HSD reduces postinjury risk for infectious complications.

Arginine in burn injury improves cardiac performance and prevents bacterial translocation

1998 ◽  
Vol 84 (2) ◽  
pp. 695-702 ◽  
Author(s):  
Jureta W. Horton ◽  
Jean White ◽  
David Maass ◽  
Billy Sanders
Keyword(s):  
Blood Pressure ◽  
Bacterial Translocation ◽  
Fluid Resuscitation ◽  
Burn Injury ◽  
Total Body Surface Area ◽  
Cardiac Performance ◽  
Pharmacological Intervention ◽  
Adult Rats ◽  
Burn Trauma ◽  
Cardiac Contractile

Horton, Jureta W., Jean White, David Maass, and Billy Sanders. Arginine in burn injury improves cardiac performance and prevents bacterial translocation. J. Appl. Physiol. 84(2): 695–702, 1998.—This study examined the effects of arginine supplement of fluid resuscitation from burn injury on cardiac contractile performance and bacterial translocation after a third-degree burn comprising 43% of the total body surface area in adult rats. Before burn injury, rats were instrumented to measure blood pressure; after burn (or sham injury), paired groups of sham-burned and burned rats were given vehicle (saline), l-arginine,d-arginine, or N-methyl-l-arginine (300 mg/kg in 0.3 ml of saline 30 min, 6 h, and 23 h postburn) plus fluid resuscitation; sham-burned rats received drug only. Twenty-four hours after burn trauma, hemodynamics were measured; the animals were then killed and randomly assigned to Langendorff heart studies or to studies examining translocation of gut bacteria. Burn rats treated with vehicle,d-arginine, or N-methyl-l-arginine had well-defined cardiocirculatory responses that included hypotension, tachycardia, respiratory compensation for metabolic acidosis, hypocalcemia, cardiac contractile depression, and significant bacterial translocation. Compared with values measured in vehicle-treated burn rats, l-arginine given after burn improved blood pressure, prevented tachycardia, reduced serum lactate levels, improved cardiac performance, and significantly reduced bacterial translocation, confirming thatl-arginine administration after burn injury provided significant cardiac and gastrointestinal protection. Circulating neutrophil counts fell after burn trauma and serum glucagon levels rose, but these changes were not altered by pharmacological intervention. Our finding of significantly higher coronary perfusate guanosine 3′,5′-cyclic monophosphate concentration inl-arginine-treated burn rats suggests that the beneficial effects ofl-arginine were mediated by nitric oxide production.

Role of interleukin-6 in cardiac inflammation and dysfunction after burn complicated by sepsis

2007 ◽  
Vol 292 (5) ◽  
pp. H2408-H2416 ◽  
Author(s):  
Hongchao Zhang ◽  
Huan-You Wang ◽  
Rhonda Bassel-Duby ◽  
David L. Maass ◽  
William E. Johnston ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Total Body Surface Area ◽  
Left Ventricular ◽  
Myocardial Inflammation ◽  
Contractile Dysfunction ◽  
Cardiac Inflammation ◽  
Tnf Α

To examine the role of myocardial interleukin-6 (IL-6) in myocardial inflammation and dysfunction after burn complicated by sepsis, we performed 40% total body surface area contact burn followed by late (7 days) Streptococcus pneumoniae pneumonia sepsis in wild-type (WT) mice, IL-6 knockout (IL-6 KO) mice, and transgenic mice overexpressing IL-6 in the myocardium (TG). Twenty-four hours after sepsis was induced, isolated cardiomyocytes were harvested and cultured in vitro, and supernatant concentrations of IL-6 and tumor necrosis factor (TNF)-α were measured. Cardiomyocyte intracellular calcium ([Ca2+]i) and sodium ([Na+]i) concentrations were also determined. Separate mice in each group underwent in vivo global hemodynamic and cardiac function assessment by cannulation of the carotid artery and insertion of a left ventricular pressure volume conductance catheter. Hearts from these mice were collected for histopathological assessment of inflammatory response, fibrosis, and apoptosis. In the WT group, there was an increase in cardiomyocyte TNF-α, [Ca2+]i, and [Na+]i after burn plus sepsis, along with cardiac contractile dysfunction, inflammation, and apoptosis. These changes were attenuated in the IL-6 KO group but accentuated in the TG group. We conclude myocardial IL-6 mediates cardiac inflammation and contractile dysfunction after burn plus sepsis.

Hypertonic saline-dextran suppresses burn-related cytokine secretion by cardiomyocytes

2001 ◽  
Vol 280 (4) ◽  
pp. H1591-H1601 ◽  
Author(s):  
Jureta W. Horton ◽  
David L. Maass ◽  
Jean White ◽  
Billy Sanders
Keyword(s):  
Hypertonic Saline ◽  
Burn Injury ◽  
Contractile Function ◽  
Total Body Surface Area ◽  
Isotonic Saline ◽  
Cytokine Secretion ◽  
Cardiac Contraction ◽  
Burn Trauma ◽  
Lps Challenge ◽  
Tnf Α

Whereas hypertonic saline-dextran (HSD, 7.5% NaCl in 6% D70) improves cardiac contractile function after burn trauma, the mechanisms of HSD-related cardioprotection remain unclear. We recently showed that cardiomyocytes secrete tumor necrosis factor-α (TNF-α), a response that was enhanced by burn trauma. This study addressed the question: does HSD modulate cardiac contraction/relaxation by altering cardiomyocyte TNF-α secretion? Wistar-Furth rats (325 g) were given a burn injury over 40% of the total body surface area and were then randomized to receive a bolus of either isotonic saline or HSD (4 ml/kg, n = 14 rats/group). Sham burn rats were given either isotonic saline or HSD ( n = 14 rats/group) to provide appropriate controls for the two burn groups. Hearts were isolated 24 h postburn for either Langendorff perfusion ( n = 8 hearts/group) or to prepare cardiomyocytes ( n = 6 hearts/group). Myocytes were stimulated with lipopolysaccharide (LPS) (0, 10, 25, or 50 μg for 18 h) to measure cytokine secretion. Burn trauma increased myocyte TNF-α and interleukin-1β and -6 secretion, exacerbated cytokine response to LPS stimulus, and impaired cardiac contraction. HSD treatment of burns decreased cardiomyocyte cytokine secretion, decreased responsiveness to LPS challenge with regard to cytokine secretion, and improved ventricular function. These data suggest that HSD mediates cardioprotection after burn trauma, in part, by downregulating cardiomyocyte secretion of inflammatory cytokines.

scholarly journals IκB overexpression in cardiomyocytes prevents NF-κB translocation and provides cardioprotection in trauma

2003 ◽  
Vol 284 (3) ◽  
pp. H804-H814 ◽  
Author(s):  
Deborah L. Carlson ◽  
D. Jean White ◽  
David L. Maass ◽  
Robin C. Nguyen ◽  
Brett Giroir ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cardiac Tissue ◽  
Nuclear Translocation ◽  
Total Body Surface Area ◽  
Nuclear Factor Κb ◽  
Cardiac Performance ◽  
Wild Type ◽  
Burn Trauma ◽  
Tnf Α ◽  
Cardiac Contractile Dysfunction

This study examined the effects of either IκBα overexpression (transgenic mice) or N-acetyl-leucinyl-leucinyl-norleucinal (ALLN) administration (proteosome inhibitor in wild-type mice) on cardiomyocyte secretion of tumor necrosis factor-α (TNF-α) and on cardiac performance after burn trauma. Transgenic mice were divided into four experimental groups. IκBα overexpressing mice were given a third-degree scald burn over 40% of the total body surface area or wild-type littermates were given either a scald or sham burn to provide appropriate controls. Pharmacological studies included ALLN (20 mg/kg) administration in either burned wild-type mice or wild-type shams. Burn trauma in wild-type mice promoted nuclear factor-κB (NF-κB) nuclear translocation, cardiomyocyte secretion of TNF-α, and impaired cardiac performance. IκBα overexpression or ALLN treatment of burn trauma prevented NF-κB activation in cardiac tissue, prevented cardiomyocyte secretion of TNF-α, and ablated burn-mediated cardiac contractile dysfunction. These data suggest that NF-κB activation and inflammatory cytokine secretion play a significant role in postburn myocardial abnormalities.

scholarly journals HDAC2 is required by the physiological concentration of glucocorticoid to inhibit inflammation in cardiac fibroblasts

2017 ◽  
Vol 95 (9) ◽  
pp. 1030-1038 ◽  
Author(s):  
Haining Zhang ◽  
Yanhua He ◽  
Guiping Zhang ◽  
Xiaobin Li ◽  
Suikai Yan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cardiac Fibroblasts ◽  
Myocardial Inflammation ◽  
Physiological Concentration ◽  
Physiological Level ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Inflammatory Action

We previously suggested that endogenous glucocorticoids (GCs) may inhibit myocardial inflammation induced by lipopolysaccharide (LPS) in vivo. However, the possible cellular and molecular mechanisms were poorly understood. In this study, we investigated the role of physiological concentration of GCs in inflammation induced by LPS in cardiac fibroblasts and explored the possible mechanisms. The results showed that hydrocortisone at the dose of 127 ng/mL (equivalent to endogenous basal level of GCs) inhibited LPS (100 ng/mL)-induced productions of TNF-α and IL-1β in cardiac fibroblasts. Xanthine oxidase/xanthine (XO/X) system impaired the anti-inflammatory action of GCs through downregulating HDAC2 activity and expression. Knockdown of HDAC2 restrained the anti-inflammatory effects of physiological level of hydrocortisone, and blunted the ability of XO/X system to downregulate the inhibitory action of physiological level of hydrocortisone on cytokines. These results suggested that HDAC2 was required by the physiological concentration of GC to inhibit inflammatory response. The dysfunction of HDAC2 induced by oxidative stress might be account for GC resistance and chronic inflammatory disorders during the cardiac diseases.

scholarly journals Burn injury induces intestinal inflammatory response mediated by Th17 in burn-primed endotoxemic mice

2020 ◽  
Author(s):  
Kazuhiko Sekine ◽  
Takayuki Shibusawa ◽  
Seitaro Fujishima ◽  
Naoki Aikawa ◽  
Junichi Sasaki
Keyword(s):  
Lamina Propria ◽  
Mononuclear Cells ◽  
Burn Injury ◽  
Inflammatory Responses ◽  
Total Body Surface Area ◽  
Vital Role ◽  
Mice Model ◽  
Th17 Response ◽  
Lamina Propria Mononuclear Cells ◽  
Tnf Α

Objective: This study aimed to elucidate the mechanism underlying the susceptibility to infection-related acute lung injury by focusing on the role of gut mucosal T-helper (Th) 17 cells that preferentially produce IL-17 with probiotics in a burn-primed endotoxemic mice model. Methods: Mice were subjected to a 15% total body surface area third-degree burn. Survival from lethal lipopolysaccharide (LPS) administration (3 mg/kg) on 11th day post burn was assessed in mice fed by chow with or without 1.2% Lactobacillus powder after burn injury. Lamina propria mononuclear cells were enzymatically isolated from the ileum removed on 11th day post burn and incubated along with 1 μg/mL LPS or 10 μg/mL anti-CD3 antibody for 24 h; subsequently, the following seven cytokines were analyzed in the supernatant: IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10, and IL-17. Results: Lactobacillus treatment post-burn injury markedly improved survival after lethal endotoxemia in burn-primed mice (64.3% vs. 21.4%, p = 0.03). The production of proinflammatory cytokines such as TNF-α, IL-6, and IL-17 by lamina propria mononuclear T-lymphocytes and macrophages including Th17 response was augmented by burn injury but decreased with Lactobacillus treatment after burn injury. Conclusions: Th17- and Th17-mediated inflammatory responses in the gut mucosa may play a vital role, which could be attenuated by Lactobacillus treatment, in survival of lethal endotoxemia in burn-primed mice.

PAF receptor antagonist modulates neutrophil responses with thermal injury in vivo

2001 ◽  
Vol 281 (4) ◽  
pp. C1310-C1317 ◽  
Author(s):  
Nadeem Fazal ◽  
Walid M. Al-Ghoul ◽  
Mashkoor A. Choudhry ◽  
Mohammed M. Sayeed
Keyword(s):  
Receptor Antagonist ◽  
Burn Injury ◽  
Total Body Surface Area ◽  
Platelet Activating Factor ◽  
Skin Thickness ◽  
Reactive Oxygen Intermediate ◽  
Paf Receptor ◽  
Paf Receptor Antagonist

The role of platelet-activating factor (PAF) in Ca2+signaling and Ca2+-related enhancement of reactive oxygen intermediate (ROI) generation in neutrophils of burn-injured rats was ascertained by evaluating the effect of treatment of the rats with a PAF receptor antagonist. The treatment of rats with the antagonist also allowed us to evaluate the role of PAF in the priming of neutrophil ROI response with burn in vivo. A full skin thickness burn injury was produced in anesthetized rats by exposing 30% of total body surface area to 98°C water for 10 s. Sham and burn rats were killed 1 day later, and their blood was collected to obtain neutrophils. Fluorescence-activated cell sorter analysis was used to quantify ROI production by the neutrophils. Cytosolic-free Ca2+concentration ([Ca2+]i) imaging technique was employed to measure neutrophil [Ca2+]iin individual cells and microfluorometry for the assessment of [Ca2+]iresponses in suspensions of neutrophils. There was an overt enhancement of ROI generation by burn rat neutrophils. ROI release was accompanied by a marked elevation of [Ca2+]isignaling. The treatment of rats with PAF receptor antagonist before burn prevented the upregulation of both [Ca2+]iand ROI generation in neutrophils. These studies indicate that enhanced ROI production in neutrophils in the early stages after burn injury results from a PAF-mediated priming of the [Ca2+]isignaling pathways in vivo.

Role of p38 mitogen-activated protein kinase in cardiac myocyte secretion of the inflammatory cytokine TNF-α

2001 ◽  
Vol 280 (5) ◽  
pp. H1970-H1981 ◽  
Author(s):  
Cherry Ballard-Croft ◽  
D. Jean White ◽  
David L. Maass ◽  
Dixie Peters Hybki ◽  
Jureta W. Horton
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Cardiac Myocyte ◽  
Total Body Surface Area ◽  
Mitogen Activated Protein Kinase ◽  
Kinase Assay ◽  
Burn Trauma ◽  
Mapk Activity ◽  
Tnf Α ◽  
Mitogen Activated Protein

This study examined the hypothesis that burn trauma promotes cardiac myocyte secretion of inflammatory cytokines such as tumor necrosis factor (TNF)-α and produces cardiac contractile dysfunction via the p38 mitogen-activated protein kinase (MAPK) pathway. Sprague-Dawley rats were divided into four groups: 1) sham burn rats given anesthesia alone, 2) sham burn rats given the p38 MAPK inhibitor SB203580 (6 mg/kg po, 15 min; 6- and 22-h postburn), 3) rats given third-degree burns over 40% total body surface area and treated with vehicle (1 ml of saline) plus lactated Ringer solution for resuscitation (4 ml · kg−1 · percent burn−1), and 4) burn rats given injury and fluid resuscitation plus SB203580. Rats from each group were killed at several times postburn to examine p38 MAPK activity (by Western blot analysis or in vitro kinase assay); myocardial function and myocyte secretion of TNF-α were examined at 24-h postburn. These studies showed significant activation of p38 MAPK at 1-, 2-, and 4-h postburn compared with time-matched shams. Burn trauma impaired cardiac mechanical performance and promoted myocyte secretion of TNF-α. SB203580 inhibited p38 MAPK activity, reduced myocyte secretion of TNF-α, and prevented burn-mediated cardiac deficits. These data suggest p38 MAPK activation is one aspect of the signaling cascade that culminates in postburn secretion of TNF-α and contributes to postburn cardiac dysfunction.

scholarly journals Reducing susceptibility to bacteremia after experimental burn injury: a role for selective decontamination of the digestive tract

2007 ◽  
Vol 102 (6) ◽  
pp. 2207-2216 ◽  
Author(s):  
Jureta W. Horton ◽  
David L. Maass ◽  
Jean White ◽  
Joseph P. Minei
Keyword(s):  
Digestive Tract ◽  
Cardiac Myocyte ◽  
Burn Injury ◽  
Inflammatory Responses ◽  
Left Ventricular ◽  
Selective Decontamination ◽  
Myocardial Inflammation ◽  
Oral Gavage ◽  
Experimental Burn ◽  
Tnf Α

We proposed that selective decontamination of the digestive tract (SDD) initiated after experimental burn injury would decrease myocardial inflammation and dysfunction after a second insult such as septic challenge. Rats were divided into eight experimental groups. Groups included sham burn plus sham sepsis, burn alone, sepsis alone, and burn plus sepsis given either water by oral gavage for 5 days after burn (or sham burn) or given oral antibiotics (polymyxin E, 15 mg; tobramycin, 6 mg; 5-flucytosin, 100 mg given by oral gavage, 2× daily for 5 days after burn or sham burn). Cardiac function and inflammation were studied 24 h after septic challenge. In the absence of SDD, burn alone, sepsis alone, or burn plus septic challenge promoted cardiac myocyte secretion of TNF-α (burn, 174 ± 11; sepsis, 269 ± 19; burn + sepsis, 453 ± 14 pg/ml), IL-1β (burn, 35 ± 2; sepsis, 29 ± 1; burn + sepsis, 48 ± 7 pg/ml), and IL-6 (burn, 143 ± 18; sepsis, 116 ± 3; burn + sepsis, 248 ± 12 pg/ml) compared with values measured in sham (TNF-α, 3 ± 1; IL-1β, 1 ± 0.4; IL-6, 6 ± 1.5 pg/ml) ( P < 0.05). Impaired ventricular contraction and relaxation responses were evident in the absence of SDD [burn + sepsis: left ventricular pressure (LVP), 65 ± 4 mmHg; rate of LVP rise (+dP/d t), 1,320 ± 131 mmHg/s compared with values measured in sham: LVP, 96 ± 4 mmHg; +dP/d t, 2,095 ± 99 mmHg/s, P < 0.05]. SDD treatment of experimental burn attenuated septic challenge-related inflammatory responses and improved myocardial contractile responses, producing cardiac TNF-α, IL-1β, and IL-6 levels, LVP, +dP/d t, and rate of LVP fall (−dP/d t) values that were significantly better ( P < 0.05) than values measured in burn plus sepsis in the absence of SDD. This work confirms that endogenous gut organisms contribute to sensitivity to subsequent infectious challenge.

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