Flutamide restores cardiac function after trauma-hemorrhage via an estrogen-dependent pathway through upregulation of PGC-1

Sex or gender differences in treatment outcomes of sepsis and septic shock

Gender disparities in intensive care unit (ICU) treatment approaches and outcomes are evident. However, clinicians often pay little attention to the importance of biological sex and sociocultural gender in their treatment courses. Previous studies have reported that differences between sexes or genders can significantly affect the manifestation of diseases, diagnosis, clinicians' treatment decisions, scope of treatment, and treatment outcomes in the intensive care field. In addition, numerous reports have suggested that immunomodulatory effects of sex hormones and differences in gene expression from X chromosomes between genders might play a significant role in treatment outcomes of various diseases. However, results from clinical studies are conflicting. Recently, the need for customized treatment based on physical, physiological, and genetic differences between females and males and sociocultural characteristics of society have been increasingly emphasized. However, interest in and research into this field are remarkably lacking in Asian countries, including South Korea. Through this review, we hope to enhance our awareness of the importance of sex and gender in intensive care treatment and research by briefly summarizing several principal issues, mainly focusing on sex and sex hormone-based outcomes in patients admitted to the ICU with sepsis and septic shock.

17 β-Estradiol Impedes Aortic Root Dilation and Rupture in Male Marfan Mice

Marfan syndrome causes a hereditary form of thoracic aortic aneurysms with worse outcomes in male compared to female patients. In this study, we examine the effects of 17 β-estradiol on aortic dilation and rupture in a Marfan mouse model. Marfan male mice were administered 17 β-estradiol, and the growth in the aortic root, along with the risk of aortic rupture, was measured. Transcriptomic profiling was used to identify enriched pathways from 17 β-estradiol treatments. Aortic smooth muscle cells were then treated with cytokines to validate functional mechanisms. We show that 17 β-estradiol decreased the size and rate of aortic root dilation and improved survival from rupture. The Marfan transcriptome was enriched in inflammatory genes, and the addition of 17 β-estradiol modulated a set of genes that function through TNFα mediated NF-κB signaling. In addition, 17 β-estradiol suppressed the induction of these TNFα induced genes in aortic smooth muscle cells in vitro in an NF-κB dependent manner, and 17 β-estradiol decreased the formation of adventitial inflammatory foci in aortic roots in vivo. In conclusion, 17 β-estradiol protects against the dilation and rupture of aortic roots in Marfan male mice through the inhibition of TNFα-NF-κB signaling.

17 β-estradiol impedes aortic root dilation and rupture in male Marfan mice

Marfan syndrome causes a hereditary form of thoracic aortic aneurysms with dilation of the aortic root. Human and animal models suggest a worse phenotype for males compared to females with respect to aneurysm size and risk of dissection. In this study we examine the effects of 17 β-estradiol on aortic dilation and rupture in a Marfan mouse model. Marfan male mice were administered 17 β-estradiol and the growth in aortic root size along with the risk of aortic rupture or dissection with the addition of angiotensin II was measured. Transcriptomic profiling was used to identify enriched pathways from 17 β-estradiol treatment. Aortic smooth muscle cells were then treated with cytokines in order to validate the mechanism of 17 β-estradiol protection. We show that 17 β-estradiol decreased the size and rate of aortic root dilation and improved survival from rupture and dissection after treatment with angiotensin II. The Marfan transcriptome was enriched in inflammatory genes and the addition of 17 β-estradiol modulated a set of genes that function through TNFα mediated NF-κB signaling. These included many proteins known to play a role in the phenotypic shift of aortic smooth muscle cells from a contractile to a more inflammatory-like state such as Vcam-1, Mcp-1, Lgals3, Il-6, Il-1b, and C3. In addition, 17 β-estradiol suppressed the induction of these TNFα induced genes in aortic smooth muscle cells in vitro and this effect appears to be NF-κB dependent. In conclusion, 17 β-estradiol protects against the dilation and rupture of aortic roots in Marfan male mice through the inhibition of TNFα -NF-κB signaling and thus prevents the phenotypic switch of aortic smooth muscle cells from a contractile to an inflammatory state.

Sex- and Gender-Dependent Differences in Clinical and Preclinical Sepsis

ABSTRACT

In this mini-review we provide an overview of sex- and gender-dependent issues in both clinical and preclinical sepsis. The increasing recognition for the need to account for sex and gender in biomedical research brings a unique set of challenges and requires researchers to adopt best practices when conducting and communicating sex- and gender-based research. This may be of particular importance in sepsis, given the potential contribution of sex bias in the failures of translational sepsis research in adults and neonates. Clinical evidence of sex-dependent differences in sepsis is equivocal. Since clinical studies are limited to observational data and confounded by a multitude of factors, preclinical studies provide a unique opportunity to investigate sex differences in a controlled, experimental environment. Numerous preclinical studies have suggested that females may experience favorable outcomes in comparison with males. The underlying mechanistic evidence for sex-dependent differences in sepsis and other models of shock (e.g., trauma-hemorrhage) largely centers around the beneficial effects of estrogen. Other mechanisms such as the immunosuppressive role of testosterone and X-linked mosaicism are also thought to contribute to observed sex- and gender-dependent differences in sepsis. Significant knowledge gaps still exist in this field. Future investigations can address these gaps through careful consideration of sex and gender in clinical studies, and the use of clinically accurate preclinical models that reflect sex differences. A better understanding of sex-and gender-dependent differences may serve to increase translational research success.

PGC-1α deficiency reveals sex-specific links between cardiac energy metabolism and EC-coupling during development of heart failure in mice

Aims

Biological sex has fundamental effects on mammalian heart physiology and pathogenesis. While it has been established that female sex is a protective factor against most cardiovascular diseases (CVDs), this beneficial effect may involve pathways associated with cardiac energy metabolism. Our aim was to elucidate the role of transcriptional coactivator PGC-1α in sex dimorphism of heart failure (HF) development.

Methods and results

Here, we show that mice deficient in cardiac expression of the peroxisome proliferator-activated receptor gamma (PPAR-γ) coactivator-1α (PGC-1α) develop dilated HF associated with changes in aerobic and anaerobic metabolism, calcium handling, cell structure, electrophysiology, as well as gene expression. These cardiac changes occur in both sexes, but female mice develop an earlier and more severe structural and functional phenotype associated with dyssynchronous local calcium release resulting from disruption of t-tubular structures of the cardiomyocytes.

Conclusions

These data reveal that the integrity of the subcellular Ca²⁺ release and uptake machinery is dependent on energy metabolism and that female hearts are more prone to suffer from contractile dysfunction in conditions with compromised production of cellular energy. Furthermore, these findings suggest that PGC-1α is a central mediator of sex-specific differences in heart function and CVD susceptibility.

Estrogen/ERα signaling axis participates in osteoblast maturation via upregulating chromosomal and mitochondrial complex gene expressions

Estrogen deficiency usually leads to bone loss and osteoporosis in postmenopausal women. Osteoblasts play crucial roles in bone formation. However, osteoblast functions are influenced by mitochondrial bioenergetic conditions. In this study, we investigated the roles of the estrogen and estrogen receptor alpha (ERα) axis in mitochondrial energy metabolism and subsequent osteoblast mineralization. Exposure of rat calvarial osteoblasts to estradiol caused substantial improvements in alkaline phosphatase activities and cell calcification. In parallel, treatment of human osteoblast-like U2OS cells, derived from a female osteosarcoma patient, with estradiol specifically augmented ERα levels. Sequentially, estradiol stimulated translocation of ERα to nuclei in human osteoblasts and induced expressions of genomic respiratory chain complex NDUFA10, UQCRC1, cytochrome c oxidase (COX)8A, COX6A2, COX8C, COX6C, COX6B2, COX412, and ATP12A genes. Concurrently, estradiol stimulated translocation of ERα to mitochondria from the cytoplasm. A bioinformatic search found the existence of four estrogen response elements in the 5’-promoter region of the mitochondrial cox i gene. Interestingly, estradiol induced COX I mRNA and protein expressions in human osteoblasts or rat calvarial osteoblasts. Knocking-down ERα translation concurrently downregulated estradiol-induced COX I mRNA expression. Consequently, exposure to estradiol led to successive increases in the mitochondrial membrane potential, the mitochondrial enzyme activity, and cellular adenosine triphosphate levels. Taken together, this study showed the roles of the estradiol/ERα signaling axis in improving osteoblast maturation through upregulating the mitochondrial bioenergetic system due to induction of definite chromosomal and mitochondrial complex gene expressions. Our results provide novel insights elucidating the roles of the estrogen/ERα alliance in regulating bone formation.

Protective Effects of Estradiol on Myocardial Contractile Function Following Hemorrhagic Shock and Resuscitation in Rats

BACKGROUND

Hemorrhagic shock (HS) results in myocardial contractile dysfunction. Studies showed that 17β-estradiol protects the myocardium against contractile dysfunction. The study investigated the cardioprotective effects of treatment with 17β-estradiol before resuscitation following 1 h of HS and resuscitation.

METHODS

Male Sprague-Dawley rats were assigned to 2 sets of experimental protocols: Ex vivo and in vivo treatment and resuscitation. Each set had three experimental groups (n = 6 per group): Normotensive (N), HS and resuscitation (HS-R) and HS rats treated with 17β-estradiol (E) and resuscitated (HS-E-R). Rats were hemorrhaged over 60-min to reach a mean arterial blood pressure of 40 mmHg. In the ex vivo group, hearts were resuscitated by perfusion in the Langendorff system. In the 17β-estradiol treated group, 17β-estradiol 280 µg/kg was added for thefirst 5 min. Cardiac function was measured. Left ventricular generated pressure (LVGP) and +dP/dt were calculated. In the in vivo group, rats were treated with 17β-estradiol 280 µg/kg s.c. after 60-min HS. Resuscitation was performed in vivo by the reinfusion of the shed blood for 30-min to restore normotension.

RESULTS

Treatment with 17β-estradiol before resuscitation in ex vivo treated and resuscitated isolated hearts and in the in vivo treated and resuscitated rats following HS improved myocardial contractile function. In the in vivo treated group, LVGP and +dP/dt max were significantly higher in 17β-estradiol treated rats compared to the untreated group (LVGP 136.40 ± 6.61 compared to 47.58 ± 17.55, and +dP/dt 661.85 ± 49.88 compared to 88.18 ± 0.85). Treatment with 17β-estradiol improved LVGP following HS.

CONCLUSIONS

The results indicate that treatment with 17β-estradiol before resuscitation following HS protects the myocardium against dysfunction.

Hepatoprotective effect of casodex after trauma hemorrhage in a rodent model

Casodex (bicalutamide), an androgen receptor antagonist, is used for the treatment of prostate cancer. Recent evidences show that Akt signaling pathway exerts organ-protective effects after injury. The aim of this study was to investigate whether Akt plays any role in the casodex-mediated attenuation of hepatic injury after trauma-hemorrhagic shock. Male Sprague-Dawley rats underwent trauma hemorrhage (mean blood pressure kept at approximately 35-40 mm Hg for 90 min), followed by fluid resuscitation. During resuscitation, a single dose of casodex (5 mg/kg, intravenous) with and without a phosphatidylinositol 3-kinase inhibitor wortmannin (1 mg/kg, intravenous), wortmannin or vehicle was administered. Plasma aspartate aminotransferase and alanine aminotransferase levels and various hepatic parameters were measured at 24 h after resuscitation. One-way analysis of variance and the Tukey test were used for statistical analysis. These results showed that trauma hemorrhage increased hepatic myeloperoxidase activity, interleukin 6 and intercellular adhesion molecule 1 levels, and plasma aspartate aminotransferase and alanine aminotransferase concentrations. In the trauma hemorrhage rats treated with casodex, these parameters were significantly improved. Casodex treatment also increased hepatic phospho-Akt expression compared with vehicle-treated trauma hemorrhaged rats. Coadministration of wortmannin with casodex abolished the casodex-induced advantageous effects on the aforementioned parameters and hepatic injury. Our results suggest that the protective effect of casodex administration on attenuation of hepatic injury after trauma hemorrhage, which is, at least in part, through Akt-dependent pathway.

Role of p38 MAPK pathway in 17β-estradiol-mediated attenuation of hemorrhagic shock-induced hepatic injury

Although 17β-estradiol (E2) treatment following hemorrhagic shock or ischemic reperfusion prevents organs from dysfunction and injury, the precise mechanism remains unknown. We hypothesize that the E2-mediated attenuation of liver injury following hemorrhagic shock and fluid resuscitation occurs via the p38 mitogen-activated protein kinase (MAPK)-dependent heme oxygenase (HO)-1 pathway. After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ∼40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E2 (1 mg/kg) alone, or E2 plus p38 MAPK inhibitor SB-203580 (2 mg/kg), HO-1 inhibitor chromium mesoporphyrin-IX chloride (2.5 mg/kg) or estrogen receptor antagonist ICI 182,780 (3 mg/kg). At 2 h after hemorrhagic shock and fluid resuscitation, the liver injury markers were significantly increased compared with sham-operated control. Hemorrhagic shock resulted in a significant decrease in p38 MAPK phosphorylation compared with the shams. Administration of E2 following hemorrhagic shock normalized liver p38 MAPK phosphorylation, further increased HO-1 expression, and reduced cleaved caspase-3 levels. Coadministration of SB-203580 abolished the E2-mediated attenuation of the shock-induced liver injury markers. In addition, administration of chromium mesoporphyrin-IX chloride or ICI 182,780 abolished E2-mediated increases in liver HO-1 expression or p38 MAPK activation following hemorrhagic shock. Our results collectively suggest that the salutary effects of E2 on hepatic injury following hemorrhagic shock and resuscitation are in part mediated through an estrogen-receptor-related p38 MAPK-dependent HO-1 upregulation.

Gender differences in sepsis: cardiovascular and immunological aspects

During sepsis, a complex network of cytokine, immune, and endothelial cell interactions occur and disturbances in the microcirculation cause organ dysfunction or even failure leading to high mortality in those patients. In this respect, numerous experimental and clinical studies indicate sex-specific differences in infectious diseases and sepsis.

Female gender has been demonstrated to be protective under such conditions, whereas male gender may be deleterious due to a diminished cell-mediated immune response and cardiovascular functions. Male sex hormones, i.e., androgens, have been shown to be suppressive on cell-mediated immune responses. In contrast, female sex hormones exhibit protective effects which may contribute to the natural advantages of females under septic conditions. Thus, the hormonal status has to be considered when treating septic patients.

Therefore, potential therapies could be derived from this knowledge. In this respect, administration of female sex hormones (estrogens and their precursors) may exert beneficial effects. Alternatively, blockade of male sex hormone receptors could result in maintained immune responses under adverse circulatory conditions. Finally, administration of agents that influence enzymes synthesizing female sex hormones which attenuate the levels of pro-inflammatory agents might exert salutary effects in septic patients. Prospective patient studies are required for transferring those important experimental findings into the clinical arena.

Flutamide fails to reduce resuscitation requirements in a porcine ischemia-reperfusion model

BACKGROUND

Hemorrhagic shock and subsequent resuscitation can lead to ischemia-reperfusion injury, followed by multiorgan failure and death. Flutamide, a vasoactive nonsteroidal antiandrogen compound, is thought to improve tissue and organ perfusion. We tested whether administration of flutamide-cyclodextrin (FLU-CYD) alters physiologic parameters or resuscitation requirements in a porcine model of severe acidosis and shock secondary to combined hemorrhage + ischemia-reperfusion injury.

METHODS AND MATERIALS

Fifteen male pigs underwent a 35% blood-volume hemorrhage. Ischemia was induced by cross-clamping the supraceliac aorta for 50 min followed by reperfusion and resuscitation. FLU-CYD complex was administered during aortic clamping. Fluid resuscitation and epinephrine were titrated by protocol to maintain mean arterial pressure ≥40 mm Hg for 6 h. Sequential laboratory results were obtained and serum levels of FLU and 2-hydroxy-flutamide (FLUOH) were measured by mass spectrometry.

RESULTS

Mean requirements for injured control swine were 14.6 (± 1.21 standard error of the mean [SEM]) L crystalloid saline and 0.59 (± 0.29 SEM) g epinephrine, compared with 16.30 (± 1.33 SEM) L and 0.54 (± 0.16 SEM) g, respectively, in the FLU-CYD group (both P > 0.05). There were no significant differences in central hemodynamics between control and experimental groups. No significant differences for pH, bicarbonate, fibrinogen, or international normalized ratio were evident. FLU-CYD resuscitation was associated with a significant increase in lactate levels compared with controls (10.1 versus 5.7 mmol/L, P < 0.05). Histologic injury was significantly increased in the livers of FLU-CYD compared with sham (P = 0.022). High serum levels of FLU and the active metabolite FLUOH were measurable throughout the resuscitation period.

CONCLUSIONS

Flutamide failed to show any benefit to resuscitation in a model of severe injury and was associated with increased acidosis, hemodilution, and liver injury compared with standard crystalloid resuscitation.

Lc3 over-expression improves survival and attenuates lung injury through increasing autophagosomal clearance in septic mice

OBJECTIVE

To clarify the role of autophagy in sepsis-induced lung injury.

BACKGROUND

The role of autophagy as a protective or maladaptive response in lung cells during sepsis has not yet been determined. The lack of specificity of the autophagic process has driven the development of new approaches that assess autophagosomes from formation to fusion with lysosomes.

METHODS

Sepsis was induced by cecal ligation and puncture (CLP). The autophagic process was manipulated using the pharmacological inhibitors of the autophagy pathway. Green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) transgenic mice were further used to determine the role of autophagy.

RESULTS

The formation of autophagosomal protein LC3-II progressively accumulated in the lungs over 24 hours after CLP, with the Lc3 gene expression returning to baseline levels at 24 hours. Autophagosome-lysosome fusion, however, gradually decreased from 8 to 24 hours after CLP, suggesting impaired clearance of autophagosomes rather than upregulation of autophagy in the septic lung. In contrast, transgenic mice overexpressing the Lc3 gene exhibited increased clearance of autophagosomes and improved survival after CLP. This protective effect was also seen in decreased cell death, inflammatory responses, neutrophil accumulation, albumin leakage, and edema formation. However, blockade of autophagosome-lysosome fusion with bafilomycin A1 abolished the protective effects in transgenic mice. This indicates that Lc3 transgene attenuates lung injury/inflammation in sepsis, possibly through increasing the clearance of autophagosomes.

CONCLUSIONS

Autophagy in the septic lung represents a protective response. However, autophagy, by virtue of excessive autophagosome accumulation, may play a maladaptive role in the late stage of sepsis, leading to acute lung injury.

Resveratrol improves cardiac contractility following trauma-hemorrhage by modulating Sirt1

Mitochondria play a critical role in metabolic homeostasis of a cell. Our recent studies, based on the reported interrelationship between c-Myc and Sirt1 (mammalian orthologue of yeast sir2 [silent information regulator 2]) expression and their role in mitochondrial biogenesis and function, demonstrated a significant downregulation of Sirt1 protein expression and an upregulation of c-Myc following trauma-hemorrhage (T-H). Activators of Sirt1 are known to improve mitochondrial function and the naturally occurring polyphenol resveratrol (RSV) has been shown to significantly increase Sirt1 activity by increasing its affinity to both NAD+ and the acetylated substrate. In this study we tested the salutary effect of RSV following T-H and its influence on Sirt1 expression. Rats were subjected to T-H or sham operation. RSV (8 mg/kg body weight, intravenously) or vehicle was administered 10 min after the onset of resuscitation, and the rats were killed 2 h following resuscitation. Sirtinol, a Sirt1 inhibitor, was administered 5 min prior to RSV administration. Cardiac contractility (±dP/dt) was measured and heart tissue was tested for Sirt1, Pgc-1α, c-Myc, cytosolic cytochrome C expression and ATP level. Left ventricular function, after T-H, was improved (P < 0.05) following RSV treatment, with significantly elevated expression of Sirt1 (P < 0.05) and Pgc-1α (P < 0.05), and decreased c-Myc (P < 0.05). We also observed significantly higher cardiac ATP content, declined cytosolic cytochrome C and decreased plasma tumor necrosis factor-α in the T-H-RSV group. The salutary effect due to RSV was abolished by sirtinol, indicating a Sirt1-mediated effect. We conclude that RSV may be a useful adjunct to resuscitation fluid following T-H.

Exogenous hydrogen sulfide protects against traumatic hemorrhagic shock via attenuation of oxidative stress

OBJECTIVE

This study was designed to investigate the protective effects of exogenous hydrogen sulfide (H(2)S) on trauma-hemorrhagic shock (T-H).

MATERIALS AND METHODS

Forty-eight male Sprague-Dawley rats were anesthetized, while 32 were subjected to both midline laparotomy and hemorrhagic shock (35-40 mmHg for 90 min) by bleeding them from the femoral artery. One hour later, resuscitation was initiated with Ringer lactate. NaHS (28 μmol/kg) or vehicle alone was administered intraperitoneally at the onset of resuscitation. Two hours later, eight animals from each group were re-anesthetized to determine cardiac function, blood gas concentrations, and hepatic and renal function. Superoxide dismutase activity (SOD), malondialdehyde concentrations (MDA), and the activity of myeloperoxidase (MPO) in the serum were measured and pulmonary wet/dry (W/D) ratio and histopathologic evaluations performed.

RESULTS

NaHS resulted in an increase in mean arterial blood pressure, left ventricular pressure and positive (+dP/dt(max)) and negative (-dP/dt(max)) first derivatives of pressure as compared with the vehicle only group. The pH, PaO(2) and base excess (BE) were increased in the NaHS-treated group compared with the vehicle-treated group. Aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and serum creatinine were reduced in the NaHS-treated group. NaHS also significantly reduced the high mortality rate at 24 h otherwise caused by T-H. The NaHS-treated group showed a remarkable decrease in MDA and MPO concentrations in plasma and an increase in SOD as compared with the vehicle-treated group. Histopathologic analysis indicated less edema, congestion, inflammatory cell infiltration and necrosis in heart, lung, liver and kidney tissue in NaHS-treated group.

CONCLUSIONS

The present study demonstrates that exogenous H(2)S administered at an appropriate dose confers protective effects after T-H and resuscitation, by preventing a decrease in the antioxidant defense system.

17beta-estradiol inhibits oleic acid-induced rat VSMC proliferation and migration by restoring PGC-1alpha expression

Estrogen shows a vasoprotective role through inhibiting the proliferation and migration of vascular smooth muscle cells (VSMCs). The mechanism underlying the effect of estrogen, however, is not completely understood. Here, we explored the role of peroxisome proliferator-activated receptor-gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) in estrogen-mediated vasoprotection. Firstly, we showed that oleic acid (OA) decreased PGC-1alpha expression while stimulating VSMC proliferation and migration. In contrast, administration of VSMCs with 17beta-estradiol (E(2), 1 or 10nM) significantly restored OA-decreased PGC-1alpha expression, treatment with 10nM E(2) almost completely abolished OA-induced VSMC proliferation and migration. Secondly, by using PGC-1alpha siRNA, the inhibitory effect of E(2) on VSMC growth is strongly reduced via suppressing PGC-1alpha expression, indicating that E(2) may exert its role through restoring PGC-1alpha. Finally, E(2) (10nM) treatment inhibits OA-induced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation, however, suppression of PGC-1alpha expression abolishes this inhibitory effect of E(2). Our findings demonstrate for the first time that in OA-stimulated rat VSMCs, treatment with E(2) (1 or 10nM) diminishes VSMC proliferation and migration via restoring OA-decreased PGC-1alpha expression. This observation offers a novel molecular basis of the vasoprotective effect of estrogen.

Differential effects of flutamide and di-(2-ethylhexyl) phthalate on male reproductive organs in a rat model

Endocrine disruptors (EDs) with androgenic and anti-androgenic effects may alter reproductive function by binding to androgenic receptors (AR) and inducing or modulating AR-dependent responses in the male reproductive system. However, the molecular mechanism(s) underlying these events remains unclear. In the present study, pregnant Sprague Dawley (SD) rats were treated with testosterone propionate (TP), flutamide (Flu) and di-(2-ethylhexyl) phthalate (DEHP) from gestation days (GD) 11 to 21. Interestingly, maternal exposure to Flu or DEHP caused fluctuations in the neonatal levels of serum testosterone (T) and luteinizing hormone (LH). Serum testosterone and LH were upregulated by Flu, but these hormones were down-regulated by DEHP. The anogenital distances (AGD) of male newborns were determined at post-neonatal days (PND) 1, 21 and 63. Male rats treated prenatally with DEHP (100 mg/kg mother's body weight) or Flu showed an AGD shorter than that of control rats. At PND 63, sperm concentration, viability and motility were reduced in the maternal DEHP and Flu-treated groups. The numbers of seminiferous tubules were reduced in the Flu and DEHP-treated offspring when compared with the vehicle- and TP-treated groups, and the tubules of the testes at PND 63 were disrupted by a high dose of Flu. In addition, we found differential gene expression patterns by microarray analysis following ED exposure, particularly in sex determination-related genes. Although Flu and DEHP are considered to be identical with regard to their anti-androgenic effects, their effects on developing male reproductive organs were distinct, suggesting that Flu competes with endogenous T, while DEHP influences a different step in androgenesis.

The role of estrogen and receptor agonists in maintaining organ function after trauma-hemorrhage

Sex is increasingly recognized as a major factor in the outcome of patients who have trauma and sepsis. Moreover, sex steroids influence chemokine/adhesion molecule expression and neutrophil accumulation. Heat shock proteins, heat shock factor 1, and peroxisome proliferator-activated receptor [gamma] coactivator 1 are regulated by the estrogen receptors and consequently contribute to organ protection after trauma-hemorrhage. Additionally, sex steroids regulate inflammatory cytokines, leading to increased morbidity and mortality. This article deals with trauma-hemorrhage and examines the following: 1) the evidence for sex differences; 2) the mechanisms by which sex hormones affect organ protection; 3) the tissue-specific effect of sex hormone receptors; and 4) the effect of genomic and nongenomic (i.e. membrane-initiated steroid signaling) pathways of sex hormones after trauma. The available information indicates that sex steroids modulate cardiovascular responses after trauma. Thus, alteration or modulation of the prevailing hormone milieu at the time of injury seems to be a novel therapeutic option for improving outcome after injury

Estradiol's salutary effects on keratinocytes following trauma-hemorrhage are mediated by estrogen receptor (ER)-alpha and ER-beta

Although administration of 17beta-estradiol (estrogen) following trauma-hemorrhage attenuates the elevation of cytokine production and mitogen-activated protein kinase (MAPK) activation in epidermal keratinocytes, whether the salutary effects of estrogen are mediated by estrogen receptor (ER)-alpha or ER-beta is not known. To determine which estrogen receptor is the mediator, we subjected C3H/HeN male mice to trauma-hemorrhage (2-cm midline laparotomy and bleeding of the animals to a mean blood pressure of 35 mmHg and maintaining that pressure for 90 min) followed by resuscitation with Ringer's lactate (four times the shed blood volume). At the middle of resuscitation we subcutaneously injected ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), estrogen (50 microg/kg), or ER antagonist ICI 182,780 (150 microg/kg). Two hours after resuscitation, we isolated keratinocytes, stimulated them with lipopolysaccharide for 24 h (5 microg/mL for maximum cytokine production), and measured the production of interleukin (IL)-6, IL-10, IL-12, and TNF-alpha and the activation of MAPK. Keratinocyte cytokine production markedly increased and MAPK activation occurred following trauma-hemorrhage but were normalized by administration of estrogen, PPT, and DPN. PPT and DPN administration were equally effective in normalizing the inflammatory response of keratinocytes, indicating that both ER-alpha and ER-beta mediate the salutary effects of estrogen on keratinocytes after trauma-hemorrhage.

Sex-specific pathways in early cardiac response to pressure overload in mice

Pressure overload (PO) first causes cardiac hypertrophy and then heart failure (HF), which are associated with sex differences in cardiac morphology and function. We aimed to identify genes that may cause HF-related sex differences. We used a transverse aortic constriction (TAC) mouse model leading to hypertrophy without sex differences in cardiac function after 2 weeks, but with sex differences in hypertrophy 6 and 9 weeks after TAC. Cardiac gene expression was analyzed 2 weeks after surgery. Deregulated genes were classified into functional gene ontology (GO) categories and used for pathway analysis. Classical marker genes of hypertrophy were similarly upregulated in both sexes (α-actin, ANP, BNP, CTGF). Thirty-five genes controlling mitochondrial function (PGC-1, cytochrome oxidase, carnitine palmitoyl transferase, acyl-CoA dehydrogenase, pyruvate dehydrogenase kinase) had lower expression in males compared to females after TAC. Genes encoding ribosomal proteins and genes associated with extracellular matrix remodeling exhibited relative higher expression in males (collagen 3, matrix metalloproteinase 2, TIMP2, and TGFβ2, all about twofold) after TAC. We confirmed 87% of the gene expression by real-time polymerase chain reaction. By GO classification, female-specific genes were related to mitochondria and metabolism and males to matrix and biosynthesis. Promoter studies confirmed the upregulation of PGC-1 by E2. Less downregulation of metabolic genes in female hearts and increased protein synthesis capacity and deregulation of matrix remodeling in male hearts characterize the sex-specific early response to PO. These differences could contribute to subsequent sex differences in cardiac function and HF.

Flutamide protects against trauma-hemorrhage-induced liver injury via attenuation of the inflammatory response, oxidative stress, and apopotosis

Although studies have shown that administration of testosterone receptor antagonist, flutamide, following trauma-hemorrhage, improves hepatic, cardiovascular, and immune functions, the precise cellular/molecular mechanisms responsible for producing these salutary effects remain largely unknown. To study this, male C3H/HeN mice were subjected to a midline laparotomy and hemorrhagic shock (35+/-5 mmHg for approximately 90 min), followed by resuscitation with Ringer lactate. Flutamide (25 mg/kg) or vehicle was administered subcutaneously at the onset of resuscitation, and animals were killed 2 h thereafter. Hepatic injury was assessed by plasma alpha-glutathione S-transferase concentration, liver myeloperoxidase activity, and nitrotyrosine formation. Hepatic malondialdehyde and 4-hydroxyalkenals (lipid peroxidation indicators), cellular DNA fragmentation, and the expression of inducible nitric oxide synthase and hypoxia-inducible factor-1alpha were also evaluated. Cytokines (TNF-alpha, IL-6) and chemokines (keratinocyte-derived chemokine and monocyte chemoattractant protein-1) levels were determined by cytometric bead array. The results indicate that flutamide administration after trauma-hemorrhage reduced liver injury, which was associated with decreased levels of alpha-glutathione S-transferase, myeloperoxidase activity, nitrotyrosine formation, lipid peroxidation, and cytokines/chemokines (systemic, liver tissue, and intracellular cytokines/chemokines). Cellular apoptosis, hepatocyte hypoxia-inducible factor-1alpha, and inducible nitric oxide synthase expression were also decreased under such conditions. Thus administration of flutamide following trauma-hemorrhage protects against liver injury via reduced inflammation, cellular oxidative stress, and apoptosis.

Estrogen: a novel therapeutic adjunct for the treatment of trauma-hemorrhage-induced immunological alterations

Trauma-hemorrhage leads to prolonged immune suppression, sepsis, and multiple organ failure. The condition affects all compartments of the immune system, and extensive studies have been carried out elucidating the immunological events following trauma-hemorrhage. The immune alteration observed following trauma-hemorrhage is gender dependent in both animal models and humans, though some studies in humans are contradictory. Within 30 min after trauma-hemorrhage, splenic and peritoneal macrophages, as well as T-cell function, are depressed in male animals, but not in proestrus females. Studies have also shown that the mortality [corrected] rate and the induction of subsequent sepsis following trauma-hemorrhage are significantly higher in males and ovariectomized females compared with proestrus females. These and other investigations show that sex hormones form the basis of this gender dichotomy, and administration of estrogen can ameliorate the immune depression and increase the survival rate after trauma-hemorrhage. This review specifically elaborates the studies carried out thus far demonstrating immunological alteration after trauma-hemorrhage and its modulation by estrogen. Also, estrogen was shown to produce its salutary effects through nuclear as well as extranuclear receptors. Estrogen rapidly activates several protein kinases and phosphatases, as well as the release of calcium in different cell types. The results of the studies exemplify the promise of estrogen as a therapeutic adjunct in treating adverse pathophysiological conditions following trauma-hemorrhage.

Sex differences and estrogen modulation of the cellular immune response after injury

Cell-mediated immunity is extremely important for resolution of infection and for proper healing from injury. However, the cellular immune response is dysregulated following injuries such as burn and hemorrhage. Sex hormones are known to regulate immunity, and a well-documented dichotomy exists in the immune response to injury between the sexes. This disparity is caused by differences in immune cell activation, infiltration, and cytokine production during and after injury. Estrogen and testosterone can positively or negatively regulate the cellular immune response either by aiding in resolution or by compounding the morbidity and mortality. It is apparent that the hormonal dysregulation is dependent not only on the type of injury sustained but also the amount of circulating hormones. Therefore, it may be possible to design sex-specific therapies to improve immunological function and patient outcome.

Mechanism of salutary effects of finasteride on post-traumatic immune/inflammatory response: upregulation of estradiol synthesis

OBJECTIVE

The aim of this study was to evaluate whether pretreatment with finasteride, a 5alpha-reductase inhibitor, improves immune functions after trauma-hemorrhage.

SUMMARY BACKGROUND DATA

A number of studies have provided evidence for a gender dimorphism in host defense after trauma. Under stress conditions, such as trauma-hemorrhage, androgenic hormones have immunosuppressive effects, leading to increased susceptibility to sepsis, morbidity, and mortality. Testosterone is converted by 5alpha-reductase to 5alpha-dihydrotestosterone (DHT), a more potent androgen.

METHODS

Male C3H/HeN mice (8-10 weeks) were randomly assigned to receive finasteride or vehicle for 2 days and were then subjected to trauma-hemorrhage or sham operation. Trauma-hemorrhage was induced by a midline laparotomy and approximately 90 minutes of hemorrhagic shock (blood pressure, 35 mm Hg), followed by fluid resuscitation. Animals were killed 2 hours after resuscitation or sham procedure. Plasma levels and Kupffer cell production of cytokines (TNF-alpha, IL-6, IL-10, MCP-1, KC, and MIP-1alpha), lung neutrophil infiltration, and edema were evaluated.

RESULTS

Finasteride administration prevented the increase in cytokine plasma levels, decreased DHT, and increased 17beta-estradiol plasma concentrations. In addition, neutrophil infiltration and edema formation in the lung were reduced by finasteride. The salutary effects of finasteride were abrogated after coadministration with an estrogen receptor inhibitor (ICI 182,780). Increased Kupffer cell cytokine production normally observed after trauma-hemorrhage was prevented by treatment with finasteride.

CONCLUSION

These results suggest that inhibition of 5alpha-reductase leads to the conversion of testosterone to 17beta-estradiol, which produces salutary effects on the post-traumatic immune response.

Metabolic modulators following trauma sepsis: Sex hormones

BACKGROUND

The development of metabolic perturbations following severe trauma/sepsis leading to decreased energy production, hyperglycemia, and lipolysis is often rapid. Gender is increasingly recognized as a major factor in the outcome of patients suffering from trauma/sepsis. Moreover, sex hormones influence energy, glucose, and lipid metabolism. Metabolic modulators, such as peroxisome proliferator-activated receptor-gamma coactivator-1 and peroxisome proliferator-activated receptor-alpha, which are required for mitochondrial energy production and fatty acid oxidation, are regulated by the estrogen receptor-beta and consequently contribute to cardioprotection following trauma hemorrhage. Additionally, sex steroids regulate inflammatory cytokines that cause hypermetabolism/catabolism via acute phase response, leading to increased morbidity and mortality.

MEASUREMENTS

This article examines the following: (1) the evidence for gender differences; (2) energy, glucose, and lipid metabolism and the acute phase protein response; (3) the mechanisms by which gender/sex hormones affect the metabolic modulators; and (4) the tissue-specific effect of sex hormone receptors and the effect of genomic and nongenomic pathways of sex hormones following trauma.

RESULTS AND CONCLUSIONS

The available information indicates that sex steroids not only modulate the immune/cardiovascular responses but also influence various metabolic processes following trauma. Thus, alteration or modulation of the prevailing hormone milieu at the time of injury appears to be a novel therapeutic adjunct for improving outcome after injury.

Mechanism of estrogen-mediated attenuation of hepatic injury following trauma-hemorrhage: Akt-dependent HO-1 up-regulation

Protein kinase B (Akt) is known to be involved in proinflammatory and chemotactic events in response to injury. Akt activation also leads to the induction of heme oxygenase (HO)-1. Up-regulation of HO-1 mediates potent, anti-inflammatory effects and attenuates organ injury. Although studies have shown that 17beta-estradiol (E2) prevents organ damage following trauma-hemorrhage, it remains unknown whether Akt/HO-1 plays any role in E2-mediated attenuation of hepatic injury following trauma-hemorrhage. To study this, male rats underwent trauma-hemorrhage (mean blood pressure, approximately 40 mmHg for 90 min), followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E2 (1 mg/kg body weight), E2 plus the PI-3K inhibitor (Wortmannin), or the estrogen receptor (ER) antagonist (ICI 182,780). At 2 h after sham operation or trauma-hemorrhage, plasma alpha-GST and hepatic tissue myeloperoxidase (MPO) activity, IL-6, TNF-alpha, ICAM-1, cytokine-induced neutrophil chemoattractant-1, and MIP-2 levels were measured. Hepatic Akt and HO-1 protein levels were also determined. Trauma-hemorrhage increased hepatic injury markers (alpha-GST and MPO activity), cytokines, ICAM-1, and chemokine levels. These parameters were markedly improved in the E2-treated rats following trauma-hemorrhage. E2 treatment also increased hepatic Akt activation and HO-1 expression compared with vehicle-treated, trauma-hemorrhage rats, which were abolished by coadministration of Wortmannin or ICI 182,780. These results suggest that the salutary effects of E2 on hepatic injury following trauma-hemorrhage are in part mediated via an ER-related, Akt-dependent up-regulation of HO-1.

Receptor-mediated suppression of cardiac heat-shock protein 72 expression by testosterone in male rat heart

The impact of testosterone on cardiac expression of heat-shock protein 72 (HSP72) remains to be elucidated. Male Sprague Dawley rats 10 wk of age (adult) were castrated. Four weeks later, testosterone (10 mg/kg, ip) was administered as a single dose, followed by the application of hyperthermia (HT) (43 C) at 6 h after testosterone administration. Twenty-four hours later, each heart was isolated. Cardiomyocytes were prepared from 3- to 5-d-old Wistar rats and male Sprague Dawley rats 10 wk of age. Testosterone (0.1-10 microM) was added to the medium, followed by the application of HT (42 C). Twenty-four hours later, cells were collected. We observed the following: 1) Exogenous testosterone suppressed HT-induced HSP72 expression, but castration alone had no influence. 2) HT resulted in better reperfusion-induced cardiac performance in castrated rats comparable with sham-operated rats, which was inhibited by testosterone. The number of apoptotic cells after ischemia/reperfusion was also increased by testosterone. 3) HT-induced HSP72 expression in cultured cardiomyocytes was suppressed by testosterone. 4) HT resulted in less damage to cells, including apoptosis, in response to hypoxia/reoxygenation, which was inhibited by testosterone. 5) Flutamide, a testosterone receptor blocker, cancelled the suppressive effects of testosterone on HSP72 expression. 6) The HT-induced increase in heat-shock factor 1 activity to bind to heat-shock element DNA was suppressed by testosterone, and this was reversed by flutamide. Our results indicate that testosterone potentially has inhibitory effects on cardiac HSP72 expression by modulating transcription, through testosterone receptor-mediated genomic mechanisms.

Fine needle aspiration coupled with real-time PCR: a painless methodology to study adaptive functional changes in skeletal muscle

BACKGROUND AND AIM

In this study we developed a new methodology for obtaining human skeletal muscle samples to evaluate gene expression. This approach is based on a fine needle aspiration technique, which allows us to extract a small tissue sample in a significantly less invasive manner than with classic biopsy.

METHODS AND RESULTS

Multiplex tandem RT-PCR was used to determine the mRNA levels of genes involved in ATP production and mitochondrial biogenesis in muscle tissue. Samples of vastus lateralis muscle were obtained from 21 healthy subjects with different fitness levels. The principal findings in our study show a strong correlation between PGC-1alpha and COX5B (p<0.001) and between PGC-1alpha and MT-CO2 (p=0.017) expression. Furthermore, a significant positive correlation between mtDNA content and the percentage of MHCI present in the aspired samples were found (p=0.028). These data are in agreement with current knowledge on skeletal muscle physiology and show the reliability of the proposed method.

CONCLUSION

This painless methodology can be used to investigate, in vivo, human muscle RNA and DNA adaptations in response to either physiological and/or pharmacological stimuli. This method has major clinical relevance, such as its application in clarifying the mechanisms underling metabolic and systemic disorders.

G protein-coupled receptor 30-dependent protein kinase A pathway is critical in nongenomic effects of estrogen in attenuating liver injury after trauma-hemorrhage

Although nongenomic effects of 17beta-estradiol (E2) are mediated via the estrogen receptor alpha (ER-alpha), the existence of another novel ER, G protein-coupled receptor 30 (GPR30), has been suggested as a candidate for triggering a broad range of E2-mediated signaling. GPR30 also acts independently of the ER to promote activation of the protein kinase A (PKA) pathway, which protects cells from apoptosis through Bcl-2. In this study, we examined whether the salutary effects of E2 in attenuating hepatic injury after trauma-hemorrhage are mediated via GPR30- or ER-alpha-regulated activation of PKA-dependent signaling. At 2 hours after trauma-hemorrhage, administration of E2-conjugated to bovine serum albumin (E2-BSA, membrane impermeable) or E2 induced the up-regulation of ER-alpha and GPR30 and attenuated hepatic injury. This was accompanied by increases in PKA activity and Bcl-2 expression. Inhibition of PKA in E2-BSA-treated trauma-hemorrhage rats by PKA inhibitor H89 prevented the E2-BSA attenuation of hepatic injury. Isolated hepatocytes were transfected with small interfering RNA to suppress GPR30 or ER. We found that suppression of GPR30 but not ER-alpha prevented E2-BSA- or E2-induced PKA activation and Bcl-2 expression. These results suggest that the nongenomic salutary effect of E2 in reducing hepatic injury after trauma-hemorrhage is mediated through the PKA-dependent pathway via GPR30 but not ER-alpha.

Effects of long-term flutamide treatment during development in zebra finches

The molecular mechanisms responsible for the sexual differentiation of the zebra finch song system remain mysterious. Androgen receptors are expressed in a sexually dimorphic fashion in the zebra finch song system: males have more cells expressing androgen receptors, and this sex difference appears very early in development (day 9 posthatch). Estrogen administration to hatchling females up-regulates androgen receptor expression in their song system and profoundly masculinizes their song system's morphology. Co-administering flutamide, an androgen receptor blocker, with estrogen impedes estrogen's masculinizing effects on the song system, suggesting that androgens are required for masculine development. Accordingly, to investigate further the role of androgens in the sexual differentiation of the zebra finch song system, we sought to block androgen activity in males by administering large, sustained doses of flutamide from just before androgen receptors are expressed in the song system (day 7) through to the day of sacrifice (days 61-63). Flutamide profoundly reduced the size of the testes, demonstrating that this drug and mode of administration could have a large impact on tissues. In contrast, flutamide had only a minor impact on the song system: the number of RA neurons was slightly reduced, and the corrected HVC volume showed a trend toward demasculinization. Other brain measures (uncorrected HVC, and corrected and uncorrected volumes of Area X, lMAN, RA, and Rotundus; neuron size in lMAN, HVC, and RA; and number of HVC and LMAN neurons) were not significantly affected. The present results do not support an important role for androgen in masculinizing the song circuit after posthatch day 7.

Flutamide attenuates pro-inflammatory cytokine production and hepatic injury following trauma-hemorrhage via estrogen receptor-related pathway

OBJECTIVE

To determine the mechanism by which flutamide administration following trauma-hemorrhage (T-H) decreases cytokine production and hepatic injury under those conditions.

SUMMARY BACKGROUND DATA

Although studies have demonstrated that flutamide administration following T-H improves hepatic and immune functions, the mechanism by which flutamide produces the salutary effects remains unknown.

METHODS

Male Sprague-Dawley rats underwent a 5-cm laparotomy and hemorrhagic shock (40 mm Hg for approximately 90 minutes), followed by resuscitation with 4 times the shed blood volume in the form of Ringer's lactate. Flutamide (25 mg/kg body weight, sc) was administered at the middle of resuscitation and animals were killed 2 hours thereafter. To block estrogen receptor (ER), ER antagonist ICI 182,780 was administrated with flutamide.

RESULTS

Hepatic injury, myeloperoxidase activity, nuclear factor-kappaB (NF-kappaB) DNA binding activity and protein expression of intercellular adhesion molecule-1, and cytokine-induced neutrophil chemoattractant (CINC-1 and CINC-3) markedly increased following T-H. Hepatic mRNA and plasma IL-6 levels were also elevated following T-H. The alterations in these parameters induced by T-H were significantly attenuated by flutamide administration. The decreased plasma estradiol levels following T-H were restored to sham levels in the flutamide-treated T-H animals. Coadministration of ICI 182,780 prevented those salutary effects of flutamide administration on pro-inflammatory responses and hepatic injury following T-H.

CONCLUSION

These findings suggest that the reduction in the production of pro-inflammatory mediators and hepatic injury produced by flutamide administration following T-H is likely due to the down-regulation in hepatic NF-kappaB DNA binding activity. Moreover, the salutary effects of flutamide administration appear to be mediated at least in part via ER-related pathway.

PGC-1alpha over-expression promotes recovery from mitochondrial dysfunction and cell injury

Cell death from mitochondrial dysfunction and compromised bioenergetics is common after ischemia-reperfusion injury and toxicant exposure. Thus, promoting mitochondrial biogenesis is therapeutically attractive for sustaining oxidative phosphorylation and maintaining ATP-dependent cellular functions. Here, we evaluated increased mitochondrial biogenesis prior to or after oxidant exposure in primary cultures of renal proximal tubular cells (RPTC). Over-expression of the mitochondrial biogenesis regulator PPAR-gamma cofactor-1 alpha (PGC-1alpha) in control RTPC increased basal and uncoupled cellular respiration, ATP, and mitochondria. Increasing mitochondrial number/function prior to oxidant exposure did not preserve mitochondrial function, but potentiated dysfunction and cell death. However, increased mitochondrial biogenesis after oxidant injury accelerated recovery of mitochondrial function. In oxidant treated RPTC, mitochondrial protein expression was reduced by 50%. Also, ATP and cellular respiration decreased 48 h after oxidant exposure, whereas mitochondrial function in injured RPTC over-expressing PGC-1alpha returned to control values. Thus, up-regulation of mitochondrial biogenesis after oxidant exposure accelerates recovery of mitochondrial and cellular functions.

Salutary effects of 17beta-estradiol on T-cell signaling and cytokine production after trauma-hemorrhage are mediated primarily via estrogen receptor-alpha

Although 17beta-estradiol (E2) administration following trauma-hemorrhage prevents the suppression in splenocyte cytokine production, it remains unknown whether the salutary effects of 17beta-estradiol are mediated via estrogen receptor (ER)-alpha or ER-beta. Moreover, it is unknown which signaling pathways are involved in 17beta-estradiol's salutary effects. Utilizing an ER-alpha- or ER-beta-specific agonist, we examined the role of ER-alpha and ER-beta in E2-mediated restoration of T-cell cytokine production following trauma-hemorrhage. Moreover, since MAPK, NF-kappaB, and activator protein (AP)-1 are known to regulate T-cell cytokine production, we also examined the activation of MAPK, NF-kappaB, and AP-1. Male rats underwent trauma-hemorrhage (mean arterial pressure 40 mmHg for 90 min) and fluid resuscitation. ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), 17beta-estradiol (50 microg/kg), or vehicle (10% DMSO) was injected subcutaneously during resuscitation. Twenty-four hours thereafter, splenic T cells were isolated, and their IL-2 and IFN-gamma production and MAPK, NF-kappaB, and AP-1 activation were measured. T-cell IL-2 and IFN-gamma production was decreased following trauma-hemorrhage, and this was accompanied with a decrease in T-cell MAPK, NF-kappaB, and AP-1 activation. PPT or 17beta-estradiol administration following trauma-hemorrhage normalized those parameters, while DPN administration had no effect. Since PPT, but not DPN, administration following trauma-hemorrhage was as effective as 17beta-estradiol in preventing the T-cell suppression, it appears that ER-alpha plays a predominant role in mediating the salutary effects of 17beta-estradiol on T cells following trauma-hemorrhage, and that such effects are likely mediated via normalization of MAPK, NF-kappaB, and AP-1 signaling pathways.

INFLUENCE OF SEX AND AGE ON MODS AND CYTOKINES AFTER MULTIPLE INJURIES

Although salutary effects of female sex steroids have been demonstrated not only in proestrus females but also in male animals treated with estradiol in different models of trauma, it remains unknown whether sex hormones influence post-traumatic immune response in humans. We therefore investigated the effect of sex and age on organ dysfunction and clinical course in patients with multiple injuries. Polytraumatized patients (injury severity score>16) between 16 and 65 years old admitted to the Hannover Medical School Level 1 trauma center between January 1997 and December 2001 were included. Marshall Score for multiple organ dysfunction syndrome (MODS) was calculated for at least 14 days. The length of stay in intensive care unit and the ventilator days were recorded in addition to the number of transfusions the patient received. A total of 106 males and 37 females were included in the study. Patients with MODS had increased plasma levels of IL-6, IL-8, and IL-10. Furthermore, patients with organ dysfunction had more frequent sepsis and higher mortality rates. In addition, MODS was associated with extended length of stay in the intensive care unit and increased ventilator days. Females not older than 50 years with an injury severity score greater than 25 suffered significantly less MODS and sepsis compared with age-matched males. Moreover, they had significantly lower plasma cytokines. Thus, in this prospective study, sex difference was confirmed in MODS and sepsis, with a benefit observed in females. Although the levels of sex steroids were not measured, it seems that the protective effects may be due to estrogen effects on plasma cytokines. This suggestion is based on the fact that such salutary effects were apparent predominantly in premenopausal females.

Effects of 17beta-estradiol and flutamide on splenic macrophages and splenocytes after trauma-hemorrhage

Since splenic immune functions are depressed in metestrus females following trauma-hemorrhage, we hypothesized that administration of the androgen receptor antagonist flutamide at the onset of resuscitation will maintain the immune function of the spleen following trauma-hemorrhage. Female C57BL6/J mice (metestrus state, 8-12 weeks old), underwent laparotomy and hemorrhagic shock (35.0+/-5.0 mm Hg for 90 min) and received 17beta-estradiol (50 microg/25 g), flutamide (625 microg/25 g) or 17beta-estradiol+flutamide. Four hours after resuscitation, the in vitro productive capacity of different cytokines (TNF-alpha, IL-6, IL-10, and IFN-gamma) by splenic MPhi and splenocytes were determined by flow cytometry. A significantly decreased cytokine production by both splenocytes and splenic MPhi was observed following trauma-hemorrhage compared to shams. Administration of 17beta-estradiol, flutamide and 17beta-estradiol+flutamide following trauma-hemorrhage resulted in a significant increase in the in vitro IL-6 release by splenic MPhi. The TNF-alpha productive capacity, however, was only restored by 17beta-estradiol and 17beta-estradiol+flutamide administration following trauma-hemorrhage. No significant effect of either treatment was observed with regard to the suppressed splenic MPhi IL-10 release. Anti-CD3 stimulation, administration of 17beta-estradiol and 17beta-estradiol+flutamide, but not the administration of flutamide alone resulted in a significant increased release of TNF-alpha, IL-6 and IFN-gamma compared to vehicle-treated animals. No significant effect of either treatment was found on IL-10 productive capacity. These results collectively suggest that flutamide administration following trauma-hemorrhage in females has beneficial effects on splenic immune function. However, flutamide administration in combination with estrogen does not provide any significant, additional effects over 17beta-estradiol administration alone.

Bench-to-bedside review: potential strategies to protect or reverse mitochondrial dysfunction in sepsis-induced organ failure

The pathogenesis of sepsis-induced multiple organ failure may crucially depend on the development of mitochondrial dysfunction and consequent cellular energetic failure. According to this hypothesis, interventions aimed at preventing or reversing mitochondrial damage may have major clinical relevance, although the timing of such interventions will be critical to both ensuring benefit and avoiding harm. Early correction of tissue hypoxia, strict control of glycaemia, and modulation of oxidative and nitrosative stress may afford protection during the initial, acute systemic inflammatory response. The regulated induction of a hypometabolic state resembling hibernation may protect the cells from dying once energy failure has developed, allowing the possibility of functional recovery. Repair of damaged organelles through stimulation of mitochondrial biogenesis and reactivation of cellular metabolism may accelerate resolution of the multiple organ failure syndrome.

Tissue compartment-specific role of estrogen receptor subtypes in immune cell cytokine production following trauma-hemorrhage

Although 17β-estradiol administration following trauma-hemorrhage attenuates plasma cytokines and alteration in immune cell cytokine production, it is not known whether the salutary effects are mediated via estrogen receptor (ER)-α or ER-β. Accordingly, we examined which ER subtype predominantly mediates the salutary effects of 17β-estradiol on systemic inflammatory response/immune cell cytokine production in various tissues following trauma-hemorrhage. Male rats underwent trauma-hemorrhage (mean blood pressure: 40 mmHg for 90 min) and fluid resuscitation. The ER-α agonist propyl pyrazole triol (PPT; 5 μg/kg), the ER-β agonist diarylpropionitrile (DPN; 5 μg/kg), 17β-estradiol (50 μg/kg), or vehicle (10% DMSO) was injected subcutaneously during resuscitation, and various measurements were made 24 h thereafter. 17β-Estradiol or PPT administration following trauma-hemorrhage prevented the increase in plasma IL-6 and IL-10 levels that were observed in vehicle-treated animals. IL-6 and TNF-α production by Kupffer cells increased; however, splenic macrophages (SMΦ), alveolar macrophages (AMΦ), and peripheral blood mononuclear cells (PBMC) had decreased release of these cytokines after trauma-hemorrhage. IL-10 production, however, increased in all macrophage populations. Administration of 17β-estradiol following trauma-hemorrhage prevented all of these alterations. PPT had the same effects as 17β-estradiol on IL-6 and TNF-α production by Kupffer cells and SMΦ, and DPN had the same effects on AMΦ and PBMC. The same effects as 17β-estradiol on IL-10 production were observed by PPT on Kupffer cells and DPN on PBMC. Both agonists were equally effective on SMΦ and AMΦ. Thus ER subtypes have tissue compartment-specific roles in mediating the effects of 17β-estradiol on immune cell functions following trauma-hemorrhage.

Jak/STAT/SOCS signaling circuits and associated cytokine-mediated inflammation and hypertrophy in the heart

Cytokines are important mediators of cardiac disease. Accumulating evidence indicates that members of the interleukin-6 family of cytokines promote cardiac hypertrophy through the activation of the Janus kinase-signal transducer and activator of transcription (Jak/STAT) pathway. Aberrant Jak/STAT signaling may promote progression from hypertrophy to heart failure. Suppressor of cytokine signaling (SOCS) proteins are underexplored, negative regulators of Jak/STAT signaling. SOCS proteins may also interact with other inflammatory pathways known to affect cardiac function. A better understanding of the therapeutic potential of these proteins may lead to the controlled progression of heart failure and the limitation of myocardial depression. This review summarizes the cardiophysiological effect of the IL-6 cytokine family, outlines the mechanistic pathway of Jak/STAT signaling, explores the regulatory role of SOCS proteins in the heart, and discusses the potential of using SOCS proteins clinically.

Effects of 17beta-estradiol and flutamide on inflammatory response and distant organ damage following trauma-hemorrhage in metestrus females

We hypothesized that administration of androgen receptors antagonist flutamide following trauma-hemorrhage (T-H) in metestrus females will maintain immune function and reduce remote organ damage under those conditions. Female B57BL/J6 mice (metestrus state, 8-12 weeks old) underwent laparotomy and hemorrhagic shock (35.0+/-5.0 mmHg for 90 min) and then received 17beta-estradiol (E2; 50 microg/25 g), flutamide (625 microg/25 g), or E2 + flutamide. Four hours after resuscitation, plasma cytokine and chemokine (TNF-alpha, IL-6, IL-10, IFN-gamma, and MCP-1) concentrations and their release in vitro by hepatic and pulmonary tissue macrophages (M Phi) were determined by flow cytometry. Organ damage was assessed by edema formation (wet-to-dry weight ratio) and neutrophil infiltration [myeloperoxidase (MPO) activity]. Administration of E2, flutamide, or E2 + flutamide following T-H resulted in a significant decrease in systemic TNF-alpha, IL-6, and MCP-1 concentrations under those conditions. This was accompanied by significantly decreased in vitro TNF-alpha release by Kupffer cells after administration of E2, flutamide, or E2 + flutamide. The in vitro release of proinflammatory cytokines by alveolar M Phi, however, was reduced significantly only by the addition of E2 or E2 + flutamide but not by the addition of flutamide. A significant decrease in pulmonary and hepatic edema formation as well as neutrophil infiltration in the lung was observed after E2, flutamide and E2 + flutamide administration. In contrast, hepatic neutrophil infiltration was only significantly reduced following E2 and E2 + flutamide administration. Thus, although flutamide does not produce synergistic, salutary effects with E2, its administration in females following T-H also produces salutary effects on the immune and organ function, similar to E2 administration under those conditions.

Upregulation of mitochondrial respiratory complex IV by estrogen receptor-beta is critical for inhibiting mitochondrial apoptotic signaling and restoring cardiac functions following trauma-hemorrhage

Our recent study showed that estrogen receptor (ER) beta plays a major role in mediating the salutary effects of 17beta-estradiol (E2) on cardiac function following trauma-hemorrhage (T-H). E2 is known to regulate mitochondrial DNA (mtDNA)-encoded genes including the mitochondrial respiratory complex (MRC) proteins. Depressed MRC activity has been reported to promote the release of cytochrome c from mitochondria and induce apoptosis. We hypothesized that E2 and ERbeta-mediated cardioprotection following T-H is dependent on mtDNA transcription encoding for MRC activity. To test this, male rats underwent T-H (mean BP 40 mm Hg approximately 90 min, then resuscitation). During resuscitation, rats received either ERalpha agonist propylpyrazole triol (PPT; 5 microg/kg), ERbeta agonist diarylpropionitrile (DPN; 5 microg/kg), E2 (50 microg/kg), or vehicle (10% DMSO). Another group of rats received mitochondrial respiratory complex-IV (MRC-IV) inhibitor sodium cyanide (SCN; 6 mg/kg) with or without DPN. The results indicated that 24 h after T-H, cardiac functions were depressed in the vehicle-treated but were normal in the DPN-treated rats. Moreover, E2 or DPN treatment after T-H normalized cardiac mitochondrial ERbeta expression and increased mitochondrial ERbeta DNA-binding activity. This was accompanied by an increase in MRC-IV gene expressions and activity, while MRC-I gene expression remained unchanged. Inhibition of MRC-IV in DPN-treated T-H rats by SCN abolished the DPN-mediated cardioprotection, ATP production, mitochondrial cytochrome c release, caspase-3 cleavage, and apoptosis. Thus, E2 and ERbeta-mediated cardioprotection following T-H appears to be mediated via mitochondrial ERbeta-dependent MRC-IV activity and inhibition of mitochondrial apoptotic signaling pathways.

Transverse aortic constriction leads to accelerated heart failure in mice lacking PPAR-gamma coactivator 1alpha

Heart failure is accompanied by important defects in metabolism. The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC-1alpha) is a powerful regulator of mitochondrial biology and metabolism. PGC-1alpha and numerous genes regulated by PGC-1alpha are repressed in models of cardiac stress, such as that generated by transverse aortic constriction (TAC). This finding has suggested that PGC-1alpha repression may contribute to the maladaptive response of the heart to chronic hemodynamic loads. We show here that TAC in mice genetically engineered to lack PGC-1alpha leads to accelerated cardiac dysfunction, which is accompanied by signs of significant clinical heart failure. Treating cardiac cells in tissue culture with the catecholamine epinephrine leads to repression of PGC-1alpha and many of its target genes, recapitulating the findings in vivo in response to TAC. Importantly, introduction of ectopic PGC-1alpha can reverse the repression of most of these genes by epinephrine. Together, these data indicate that endogenous PGC-1alpha serves a cardioprotective function and suggest that repression of PGC-1alpha significantly contributes to the development of heart failure. Moreover, the data suggest that elevating PGC-1alpha activity may have therapeutic potential in the treatment of heart failure.

Increased expression of alpha- and beta-globin mRNAs at the pituitary following exposure to estrogen during the critical period of neonatal sex differentiation in the rat

Deterioration of reproductive health in human and wildlife species during the past decades has drawn considerable attention to the potential adverse effects of exposure to xenosteroids during sensitive periods of sex development. The hypothalamic-pituitary (HP) unit is a key element in the neuroendocrine system controlling development and function of the reproductive axis; the HP unit being highly sensitive to the organizing effects of endogenous and exogenous sex steroids. To gain knowledge on the molecular mode of action and potential biomarkers of exposure to estrogenic compounds at the HP unit, we screened for differentially expressed genes at the pituitary and hypothalamus of rats after neonatal exposure to estradiol benzoate. Our analyses identified persistent up-regulation of alpha- and beta-globin mRNAs at the pituitary following neonatal estrogenization. This finding was confirmed by combination of RT-PCR analyses and in situ hybridization. Induction of alpha- and beta-globin mRNA expression at the pituitary by neonatal exposure to estrogen was demonstrated as dose-dependent and it was persistently detected up to puberty. In contrast, durable up-regulation of alpha- and beta-globin genes was not detected at the hypothalamus, cortex, cerebellum, liver and testis. Finally, enhanced levels of alpha- and beta-globin mRNAs at the pituitary were also demonstrated after neonatal administration of the anti-androgen flutamide. In summary, alpha- and beta-globin genes may prove as sensitive, pituitary-specific biomarkers of exposure to estrogenic (and/or anti-androgenic) compounds at critical periods of sex development, whose potential in the assessment of endocrine disrupting events at the HP unit merits further investigation.