DHEA-dependent and organ-specific regulation of TNF-alpha mRNA expression in a murine polymicrobial sepsis and trauma model

DHEA and Its Metabolites Reduce the Cytokines Involved in the Inflammatory Response and Fibrosis in Primary Biliary Cholangitis

Dehydroepiandrosterone (DHEA) is an abundant steroid and precursor of sex hormones. During aging, the reduction in DHEA synthesis causes a significant depletion of estrogens and androgens in different organs, such as the ovaries, brain, and liver. Primary Biliary Cholangitis (PBC) is a cholestatic liver disease that begins with immune-mediated bile duct damage, and is followed by liver fibrosis, and finally, cirrhosis. PBC primarily affects postmenopausal women, with an average age of diagnosis of 65 years, but younger women are also affected. Here, we analyzed the levels of DHEA, estradiol (E2), and estriol (E3) in the PBC sera of females at an age of diagnosis under 40 (n = 37) and above 65 (n = 29). Our results indicate that in PBC patients at an age of diagnosis under 40, E2 was significantly lower compared to that in healthy women. In contrast, the levels of DHEA and E3 were in a normal range. Furthermore, ELISA assays revealed that in PBC patients at an age of diagnosis above 65, the levels of DHEA, E2, and E3 significantly declined in comparison to those in younger patients. In addition, flow cytometry analysis showed that the level of IL-8 significantly decreased while the level of TNF-α increased in older PBC patients compared to younger ones. Moreover, we showed for the first time that the sulfonated form of DHEA, DHEA-S, reduces the levels of both pro-inflammatory interleukins, IL-8 and TNF-α, in PBC-like cholangiocytes (H69-miR506), while it diminishes the level of the pro-fibrotic interleukin, IL-13, in hepatocytes (Hep-G2). Finally, we demonstrated that the expression of the pro-fibrotic agent TGF-β significantly increased in both the early (F0–F3) and cirrhotic (F4) stages of PBC, and this elevation was accompanied by higher α-SMA expression.

Selective Inhibition of IL-6 Trans-Signaling Has No Beneficial Effect on the Posttraumatic Cytokine Release after Multiple Trauma in Mice

While improvements in pre-hospital and in-hospital care allow more multiple trauma patients to advance to intensive care, the incidence of posttraumatic multiple organ dysfunction syndrome (MODS) is on the rise. Herein, the influence of a selective IL-6 trans-signaling inhibition on posttraumatic cytokine levels was investigated as an approach to prevent MODS caused by a dysbalanced posttraumatic immune reaction. Therefore, the artificial IL-6 trans-signaling inhibitor sgp130Fc was deployed in a murine multiple trauma model (femoral fracture plus bilateral chest trauma). The traumatized mice were treated with sgp130Fc (FP) and compared to untreated mice (WT) and IL-6 receptor knockout mice (RKO), which received the same traumas. The overall trauma mortality was 4.4%. Microscopic pulmonary changes were apparent after multiple trauma and after isolated bilateral chest trauma. Elevated IL-6, MCP-3 and RANTES plasma levels were measured after trauma, indicating a successful induction of a systemic inflammatory reaction. Significantly reduced IL-6 and RANTES plasma levels were visible in RKO compared to WT. Only a little effect was visible in FP compared to WT. Comparable cytokine levels in WT and FP indicate neither a protective nor an adverse effect of sgp130Fc on the cytokine release after femoral fracture and bilateral chest trauma.

Validation of reference genes for expression analysis in a murine trauma model combining traumatic brain injury and femoral fracture

Systemic and local posttraumatic responses are often monitored on mRNA expression level using quantitative real-time PCR (qRT-PCR), which requires normalisation to adjust for confounding sources of variability. Normalisation requests reference (housekeeping) genes stable throughout time and divergent experimental conditions in the tissue of interest, which are crucial for a reliable and reproducible gene expression analysis. Although previous animal studies analysed reference genes following isolated trauma, this multiple-trauma gene expression analysis provides a notable study analysing reference genes in primarily affected (i.e. bone/fracture callus and hypothalamus) and secondarily affected organs (i.e. white adipose tissue, liver, muscle and spleen), following experimental long bone fracture and traumatic brain injury. We considered tissue-specific and commonly used top-ranked reference candidates from different functional groups that were evaluated applying the established expression stability analysis tools NormFinder, GeNorm, BestKeeper and RefFinder. In conclusion, reference gene expression in primary organs is highly time point as well as tissue-specific, and therefore requires careful evaluation for qRT-PCR analysis. Furthermore, the general application of Ppia, particularly in combination with a second reference gene, is strongly recommended for the analysis of systemic effects in the case of indirect trauma affecting secondary organs through local and systemic pathophysiological responses.

Neuroendocrine Modulation of the Immune Response after Trauma and Sepsis: Does It Influence Outcome?

Although the treatment of multiple-injured patients has been improved during the last decades, sepsis and multiple organ failure (MOF) still remain the major cause of death. Following trauma, profound alterations of a large number of physiological systems can be observed that may potentially contribute to the development of sepsis and MOF. This includes alterations of the neuroendocrine and the immune system. A large number of studies focused on posttraumatic changes of the immune system, but the cause of posttraumatic immune disturbance remains to be established. However, an increasing number of data indicate that the bidirectional interaction between the neuroendocrine and the immune system may be an important mechanism involved in the development of sepsis and MOF. The aim of this article is to highlight the current knowledge of the neuroendocrine modulation of the immune system during trauma and sepsis.

Dehydroepiandrosterone improves the ovarian reserve of women with diminished ovarian reserve and is a potential regulator of the immune response in the ovaries

Diminished ovarian reserve (DOR) has a high morbidity rate worldwide and has become a primary cause of infertility. DOR is a daunting obstacle in in vitro fertilization (IVF) and leads to poor ovarian response, high cancellation rates, poor IVF outcomes, and low pregnancy rates. Abnormal autoimmune function may also contribute to DOR. Dehydroepiandrosterone (DHEA) is a C19 androgenic steroid. DHEA is secreted mainly by the adrenal gland, and its secretion declines with age. DHEA has a pro-inflammatory immune function that opposes cortisol. The cortisol to DHEA ratio increases with age, which may lead to decreased immune function. DHEA supplementation helps improve this situation. A number of clinical case control studies and several prospective randomized clinical trials have observed a positive effect of DHEA supplementation in women with DOR. However, the underlying mechanism by which DHEA improves ovarian reserve remains unclear. DHEA functions as an immune regulator in many different tissues in mammals and may also play an important role in regulating the immune response in the ovaries. The conversion of DHEA to downstream sex steroids may allow it to regulate the immune response there. DHEA can also enhance the Th1 immune response and regulate the balance of the Th1/Th2 response. DHEA treatment can increase selective T lymphocyte infiltration in mice, resulting in a decline in the CD4+ T lymphocyte population and an upregulation of the CD8+ T lymphocyte population in ovarian tissue, thus regulating the balance of CD4+/CD8+ T cells. This review mainly focuses on how DHEA supplementation affects regulation of the immune response in the ovaries.

Inflammation-associated upregulation of the sulfated steroid transporter Slc10a6 in mouse liver and macrophage cell lines

AIM

Slc10a6, an incompletely characterized member of the SLC10A bile acid transporter family, was one of the most highly induced RNA transcripts identified in a screen for inflammation-responsive genes in mouse liver. This study aimed to elucidate a role for Slc10a6 in hepatic inflammation.

METHODS

Mice were treated with lipopolysaccharide (LPS; 2 mg/kg) or interleukin (IL)-1β (5 mg/kg) for various time points. Cells were treated with LPS (1 μg/mL) at various time points, with cell signaling inhibitors, nuclear receptor ligands and Slc10a6 substrates. All mRNA levels were determined by quantitative polymerase chain reaction.

RESULTS

Slc10a6 mRNA levels were upregulated in mouse liver at 2 h (7-fold), 4 h (100-fold) and 16 h (50-fold) after LPS treatment, and 35-fold by the cytokine IL-1β (4 h). Both absence of the nuclear receptor Fxr and pretreating mice with the synthetic retinoid X receptor-α ligand LG268 attenuated the LPS upregulation of Slc10a6 mRNA by 60-75%. In vitro, Slc10a6 mRNA was induced 30-fold by LPS in mouse RAW264.7 macrophages in a time-dependent manner (maximum at 8 h). The Slc10a6 substrate dehydroepiandrosterone sulfate (DHEAS) enhanced LPS induction of CCL5 mRNA, a pro-inflammatory chemokine, by 50% in RAW264.7 cells. This effect was abrogated in the presence of anti-inflammatory nuclear receptor ligands 9-cis-retinoic acid and dexamethasone.

CONCLUSION

Dramatic upregulation of Slc10a6 mRNA by LPS combined with enhanced LPS stimulation of CCL5 expression by the Slc10a6 substrate DHEAS in macrophages suggests that Slc10a6 function contributes to the hepatic inflammatory response.

Propofol inhibits lipopolysaccharide-induced tumor necrosis factor-alpha expression and myocardial depression through decreasing the generation of superoxide anion in cardiomyocytes

TNF-α has been shown to be a major factor responsible for myocardial depression in sepsis. The aim of this study was to investigate the effect of an anesthetic, propofol, on TNF-α expression in cardiomyocytes treated with LPS both in vivo and in vitro. In cultured cardiomyocytes, compared with control group, propofol significantly reduced protein expression of gp91phox and phosphorylation of extracellular regulated protein kinases 1/2 (ERK1/2) and p38 MAPK, which associates with reduced TNF-α production. In in vivo mice studies, propofol significantly improved myocardial depression and increased survival rate of mice after LPS treatment or during endotoxemia, which associates with reduced myocardial TNF-α production, gp91phox, ERK1/2, and p38 MAPK. It is concluded that propofol abrogates LPS-induced TNF-α production and alleviates cardiac depression through gp91phox/ERK1/2 or p38 MAPK signal pathway. These findings have great clinical importance in the application of propofol for patients enduring sepsis.

Dehydroepiandrosterone modulates the inflammatory response in a bilateral femoral shaft fracture model

Background

Dehydroepiandrosterone (DHEA) has been shown to have immunomodulatory effects after hemorrhage and sepsis. The present study analyzes whether DHEA is also involved in the mediation of inflammatory stimuli induced by bilateral femoral shaft fracture.

Methods

Male C57/BL6 mice (6 per group) were subjected to closed bilateral femoral shaft fracture with intramedullary nailing followed by administration of either 25 mg/kg/24 h DHEA diluted in saline with 0.1% ethanol or saline with 0.1% ethanol. The sham group was treated by isolated intramedullary nailing without fracture. Animals were sacrificed after 6, 24, or 72 h. Serum TNFα, IL-1β, IL-6, IL-10, MCP-1, and KC concentrations were measured by Bio-Plex Pro^Tm analysis. Acute pulmonary inflammation was assessed by histology, pulmonary myeloperoxidase (MPO) activity, and pulmonary IL-6 concentration.

Results

DHEA was associated with a decrease in the systemic inflammatory response induced by bilateral femoral fracture, especially systemic IL-6 (322.2 vs. 62.5 pg/mL; P = 0.01), IL-1β (1,422.6 vs. 754.1 pg/mL; P = 0.05), and MCP-1 (219.4 vs. 44.1 pg/mL; P >0.01) levels. No changes in pulmonary inflammation were measured.

Conclusion

We conclude that DHEA may be a treatment option to reduce systemic inflammation following musculoskeletal injuries although the pulmonary inflammatory reaction was not affected.

Hyperandrogenism induces a proinflammatory TNFα response to glucose ingestion in a receptor-dependent fashion

CONTEXT

Hyperandrogenism and inflammation are related in polycystic ovary syndrome (PCOS). Hyperandrogenemia can induce inflammation in reproductive-age women, but the mechanism for this phenomenon is unclear.

OBJECTIVE

We examined the in vivo and in vitro effects of hyperandrogenism on mononuclear cell (MNC)-derived androgen receptor (AR) status and TNFα release.

DESIGN

This study combined a randomized, controlled, double-blind protocol with laboratory-based cell culture experiments.

SETTING

This work was performed in an academic medical center.

PARTICIPANTS

Lean, healthy, reproductive-age women were treated with 130 mg of dehydroepiandrosterone (DHEA) or placebo (n = 8 subjects each) for 5 days and also provided untreated fasting blood samples (n = 12 subjects) for cell culture experiments.

MAIN OUTCOME MEASURES

AR mRNA content and TNFα release were measured before and after DHEA administration in the fasting state and 2 hours after glucose ingestion. TNFα release in the fasting state was also measured in cultured MNCs exposed to androgens with or without flutamide preincubation.

RESULTS

At baseline, subjects receiving DHEA or placebo exhibited no significant difference in androgens and TNFα release from MNCs before and after glucose ingestion. Compared with placebo, DHEA administration raised levels of T, androstenedione, and DHEA sulfate, and increased MNC-derived AR mRNA content and TNFα release in the fasting state and in response to glucose ingestion. Compared with MNC exposure to baseline concentrations of DHEA (175 ng/dL) or T (50 ng/dL), the absolute change in TNFα release increased after exposure to T concentrations of 125 and 250 ng/dL and a DHEA concentration of 1750 ng/dL. Preincubation with flutamide reduced the TNFα response by ≥ 60% across all T concentrations.

CONCLUSION

Androgen excess in vivo and in vitro comparable to what is present in PCOS increases TNFα release from MNCs of lean healthy reproductive-age women in a receptor-dependent fashion. Hyperandrogenemia activates and sensitizes MNCs to glucose in this population.

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.

Septic shock: desperately seeking treatment

Septic shock results from the dysregulation of the innate immune response following infection. Despite major advances in fundamental and clinical research, patients diagnosed with septic shock still have a poor prognostic outcome, with a mortality rate of up to 50%. Indeed, the reasons leading to septic shock are still poorly understood. First postulated 30 years ago, the general view of septic shock as an acute and overwhelming inflammatory response still prevails today. Recently, the fact that numerous clinical trials have failed to demonstrate any positive medical outcomes has caused us to question our fundamental understanding of this condition. New and sophisticated technologies now allow us to accurately profile the various stages and contributory components of the inflammatory response defining septic shock, and many studies now report a more complex inflammatory response, particularly during the early phase of sepsis. In addition, novel experimental approaches, using more clinically relevant animal models, to standardize and stratify research outcomes are now being argued for. In the present review, we discuss the most recent findings in relation to our understanding of the underlying mechanisms involved in septic shock, and highlight the attempts made to improve animal experimental models. We also review recent studies reporting promising results with two vastly different therapeutic approaches influencing the renin-angiotensin system and applying mesenchymal stem cells for clinical intervention.

Trauma care in Germany: an inclusive system

BACKGROUND

Development of trauma systems is a demanding process. The United States and Germany both have sophisticated trauma systems. This manuscript is a summary of political, economic, and medical changes that have led to the development of both trauma systems and the current high-quality standards.

QUESTIONS/PURPOSES

We specifically asked three questions: (1) What tasks are involved in developing a modern trauma system? (2) What is the approach to achieve this task? (3) Do these systems work?

METHODS

We conducted a systematic review of relevant articles by searching electronic databases (PubMed, Embase, Cochrane library) using the following search terms: "trauma system", "polytrauma", "trauma networks", and "trauma registry". Of 2573 retrieved manuscripts, the authors made a personal selection of studies. A personal study selection from our experiences was added when their contribution to the topic was judged important.

RESULTS

Worldwide, similar tasks concerning trauma care have to be addressed. In most societies, traffic accidents and firearm-related injuries contribute to a high number of trauma victims. The German approach has been to decrease the number of accidents through injury prevention and to provide better care by establishing an emergency medical system. For in-hospital treatment, clinical care has constantly improved and a close interaction with members from the American Association for the Surgery of Trauma and the Orthopaedic Trauma Association has helped a great deal to achieve these improvements. The German healthcare system was developed as a powerful healthcare tool covering patients from injury to rehabilitation. In addition, trauma and injury research has been strengthened to deal with various questions of trauma care.

CONCLUSIONS

Organized injury prevention programs and systematized professional patient care can address the issues associated with the global burden of trauma. These trauma systems require constant monitoring and improvement.

Cytokine productive capacity of alveolar macrophages and Kupffer cells after femoral fracture and blunt chest trauma in a murine trauma model

INTRODUCTION

Specific cellular and inflammatory factors that contribute to the severity of pulmonary dysfunction after blunt chest trauma and osteosynthesis of femoral fractures are yet not fully understood. Therefore, we investigated alterations of the cytokine productive capacity of alveolar macrophages (AM) and Kupffer cells (KC) after femoral fracture stabilized with intramedullary pin with or without blunt chest trauma.

MATERIALS AND METHODS

In male C57BL/6N mice an intramedullary pin was implanted in an intact femur as the sham procedure. In trauma groups mice either received an isolated femoral fracture with subsequent fracture stabilization with an intramedullary pin (group Fx) or a combined trauma of blunt chest trauma and femur fracture also stabilized by an intramedullary pin (group TTFx). Animals were sacrificed 0h, 6h, 12h, 24h and 3d after trauma induction. Cytokine concentrations were measured in plasma and supernatant of cultivated AM and KC by FACS analysis. Pulmonary and hepatic infiltration of polymorphonuclear leukocytes (PMN) was determined by Ly6G-staining.

RESULTS

At 6h, isolated femoral fracture with intramedullary stabilization resulted in a significantly increased productive capacity of KC (IL-6, TNF-α, CCL2, CCL3, CCL5 and CCL7) compared to sham animals. Combined trauma additionally resulted in an increased productive capacity of AM (IL-6, TNF-α, CCL2, CCL3, CCL4, CCL5 and CCL7) at 6h and the effect was prolonged up to 3d compared to controls. Combined trauma also led to a significant higher amount of plasma CCL2 at 3d and plasma CCL7 at 6h after the insult compared to group Fx. Compared to shams, pulmonary and hepatic infiltrations of PMNs were increased in group Fx and TTFx after 6h, but in the combined trauma model the effect was prolonged up to 3d.

CONCLUSION

An intramedullary stabilized femur fracture alone results in a significant activation of the immune response. The combination of femoral fracture and blunt chest trauma however, results in an increased and prolonged activation of the inflammatory response. Transferred to the clinical setting, these results emphasize the critical role of severe chest trauma for treatment strategies of femoral fractures in multiple trauma patients.

A non-lethal traumatic/hemorrhagic insult strongly modulates the compartment-specific PAI-1 response in the subsequent polymicrobial sepsis

Introduction

Plasminogen activator inhibitor 1 (PAI-1) is a key factor in trauma- and sepsis-induced coagulopathy. We examined how trauma-hemorrhage (TH) modulates PAI-1 responses in subsequent cecal ligation and puncture (CLP)-induced sepsis, and the association of PAI-1 with septic outcomes.

Methods

Mice underwent TH and CLP 48 h later in three separate experiments. In experiment 1, mice were sacrificed pre- and post-CLP to characterize the trajectory of PAI-1 in plasma (protein) and tissues (mRNA). Post-CLP dynamics in TH-CLP (this study) and CLP-Only mice (prior study) were then compared for modulatory effects of TH. In experiment 2, to relate PAI-1 changes to outcome, mice underwent TH-CLP and were sampled daily and followed for 14 days to compare non-survivors (DEAD) and survivors (SUR). In experiment 3, plasma and tissue PAI-1 expression were compared between mice predicted to die (P-DIE) and to live (P-LIVE).

Results

In experiment 1, an early post-TH rise of circulating PAI-1 was contrasted by a delayed (post-TH) decrease of PAI-1 mRNA in organs. In the post-CLP phase, profiles of circulating PAI-1 were similar between TH-CLP and CLP-Only mice. Conversely, PAI-1 mRNA declined in the liver and heart of TH-CLP mice versus CLP-Only. In experiment 2, there were no DEAD/SUR differences in circulating PAI-1 prior to CLP. Post-CLP, circulating PAI-1 in DEAD was 2–4-fold higher than in SUR. PAI-1 increase heralded septic deaths up to 48 h prior but DEAD/SUR thrombomodulin (endothelial injury marker) levels were identical. In experiment 3, levels of circulating PAI-1 and its hepatic gene expression were higher in P-DIE versus P-LIVE mice and those increases closely correlated with liver dysfunction.

Conclusions

Trauma modulated septic PAI-1 responses in a compartment-specific fashion. Only post-CLP increases in circulating PAI-1 predicted septic outcomes. In posttraumatic sepsis, pre-lethal release of PAI-1 was mostly of hepatic origin and was independent of endothelial injury.

Hyperandrogenism sensitizes leukocytes to hyperglycemia to promote oxidative stress in lean reproductive-age women

CONTEXT

Hyperandrogenism and oxidative stress are related in polycystic ovary syndrome (PCOS), but it is unknown whether hyperandrogenemia can activate oxidative stress.

OBJECTIVE

The purpose of this study was to determine the effect of oral androgen administration on fasting and glucose-stimulated leukocytic reactive oxygen species (ROS) generation, reduced nicotinamide adenine dinucleotide phosphate oxidase p47(phox) subunit gene expression, and plasma thiobarbituric acid-reactive substances (TBARS) in lean healthy reproductive-age women.

PARTICIPANTS, DESIGN, AND SETTING

Sixteen lean healthy ovulatory reproductive-age women were treated with 130 mg dehydroepiandrosterone (DHEA) or placebo (n = 8 each) for 5 d in this randomized, controlled, double-blind study that was performed at an an academic medical center.

MAIN OUTCOME MEASURES

Leukocytic ROS generation, p47(phox) gene expression, and plasma TBARS were quantified in the fasting state and 2 h after glucose ingestion, before and after treatment.

RESULTS

Before treatment, subjects receiving DHEA or placebo exhibited no differences in androgens or any prooxidant markers while fasting and after glucose ingestion. Compared with placebo, DHEA administration raised levels of testosterone, androstenedione, and DHEA-sulfate, increased the percent change in glucose-challenged p47(phox) RNA content, and increased the percent change in fasting and glucose-challenged ROS generation from mononuclear cells and polymorphonuclear cells, p47(phox) protein content, and plasma TBARS.

CONCLUSION

Elevation of circulating androgens comparable to what is present in PCOS increases leukocytic ROS generation, p47(phox) gene expression, and plasma TBARS to promote oxidative stress in lean healthy reproductive-age women. Thus, hyperandrogenemia activates and sensitizes leukocytes to glucose in this population.

Hyperandrogenism sensitizes mononuclear cells to promote glucose-induced inflammation in lean reproductive-age women

Hyperandrogenism and chronic low-grade inflammation are related in polycystic ovary syndrome (PCOS), but it is unknown whether hyperandrogenemia can activate inflammation. We determined the effect of oral androgen administration on fasting and glucose-stimulated nuclear factor-κB (NF-κB) activation and expression and related markers of inflammation in mononuclear cells (MNC) of lean reproductive-age women. Sixteen lean, ovulatory reproductive-age women were treated with 130 mg of DHEA or placebo (n = 8 each) for 5 days in a randomized, controlled, double-blind fashion. Nuclear activation of NF-κB, p65 and p105 NF-κB subunit RNA, TNFα and IL-1β mRNA, and NF-κB p65 and inhibitory-κB (IκB) protein were quantified from MNC obtained while fasting and 2 h after glucose ingestion, before and after DHEA or placebo administration. Before treatment, subjects receiving DHEA or placebo exhibited no differences in androgens or any inflammatory markers while fasting and after glucose ingestion. Compared with placebo, DHEA administration raised levels of testosterone, androstenedione, and DHEA-S, increased the percent change in fasting and glucose-challenged activated NF-κB, p65, p105, TNFα, and IL-1β RNA and p65 protein, and decreased the percent change in fasting and glucose-challenged IκB protein. We conclude that elevation of circulating androgens to the range observed in PCOS upregulates the NF-κB inflammation pathway in lean reproductive-age women. Thus, hyperandrogenemia activates and sensitizes MNC to glucose in this population.

Experimental trauma models: an update

Treatment of polytrauma patients remains a medical as well as socioeconomic challenge. Although diagnostics and therapy improved during the last decades, multiple injuries are still the major cause of fatalities in patients below 45 years of age. Organ dysfunction and organ failure are major complications in patients with major injuries and contribute to mortality during the clinical course. Profound understanding of the systemic pathophysiological response is crucial for innovative therapeutic approaches. Therefore, experimental studies in various animal models are necessary. This review is aimed at providing detailed information of common trauma models in small as well as in large animals.

Effects of hypertonic saline on CD4+CD25+Foxp3+ regulatory T cells after hemorrhagic shock in relation to iNOS and cytokines

BACKGROUND

Hemorrhagic shock and resuscitation induce immunosuppression. CD4(+)CD25(+)Foxp3(+) regulatory T Cells (Foxp3(+) Tregs), iNOS and cytokines may affect these severe conditions such as acute respiratory distress syndrome and multiple organ failure after hemorrhagic shock and resuscitation. Foxp3(+) Tregs have been described to be specific and play a key role in the control of the immune system. Immune condition may be restored by hypertonic saline resuscitation that inhibits pro-inflammatory effects of cytokine. Our aim was to investigate how hypertonic saline resuscitation affected Foxp3(+) Tregs after hemorrhagic shock and resuscitation in relation to iNOS and cytokines.

METHODS

Male C57BL6/J and B6.129P2- NOS2(tm1Lau)/J (iNOS gene knockout) mice were used in creating hemorrhagic shock model. Mice were divided into two groups, each according to the type of resuscitation. (1) Wild HS: resuscitation with hypertonic saline (4 mL/Kg of 7.5% NaCl) and the shed blood (SB); (2) wild 2LR: resuscitation with lactated Ringer's solution and the SB; (3) iNOS knockout HS: similarly resuscitated as wild HS; (4) iNOS knockout 2LR: similarly resuscitated as wild 2LR. Samples of thymus and spleen were harvested at 2, 6, 24, 48, and 72 h after resuscitation. CD4(+) T cells and Foxp3(+) Tregs were analyzed at 24, 48, and 72 h. At 2, 6, 24, and 48 h, plasma cytokines were assayed and expression of iNOS (NOS2) was also measured by immunofluorescence.

RESULTS

NOS2 of HS and 2LR wild groups at 2 and 6 h in spleen increased compared with the control group. At 6h, NOS2 in HS wild group was significantly lower than in 2LR wild group. Plasma levels of interleukin (IL)-6, TNF- α, MCP-1, and IL-10 increased at 2 h. Both in wild type and iNOS knockout mice, hypertonic saline resuscitation decreased plasma IL-6, TNF-α, and MCP-1 levels at 2 h; CD4(+) T cells in spleen and thymus decreased at 24, 48, and 72 h, and Foxp3(+) Tregs in spleen at 48 h increased, however, hypertonic saline resuscitation did not affect the Foxp3(+).

CONCLUSIONS

These results show that in early phase, the inflammatory cytokines in plasma might affect iNOS expression and cytokines. Further, this study showed that hypertonic saline resuscitation and suppression of iNOS might improve immunosuppressive reaction after hemorrhagic shock.

Dehydroepiandrosterone during sepsis: does the timing of administration influence the effectiveness

BACKGROUND

Administration of dehydroepiandrosterone (DHEA) has been demonstrated to improve survival and cellular immune functions during systemic inflammation. Although there is evidence that the time point of drug application may profoundly affect the DHEA-induced effects the impact of this parameter remains to be established.

METHODS

Male NMRI mice were subjected to sham-operation (laparotomy) or sepsis (cecal ligation and puncture). Animals received saline or DHEA (20 mg/kg/d) given subcutaneously either 1 h before or 8 h after induction of CLP. Termination of animals was performed 48 h after induction of sepsis in order to monitor splenocyte proliferation ((3)H-thymidine incorporation assay), splenocyte apoptosis (annexin V binding capacity), and cytokine release (IL-1β and IL-6, enzyme-linked immunoassay (ELISA).

RESULTS

DHEA administration improved the survival rate of septic mice 48 h after induction of CLP independent of the time point of application (44% versus 75% pretreatment groups; 47% versus 78% treatment groups). This effect was paralleled by a restoration of splenocyte proliferation, a decreased cellular apoptosis rate of splenocytes, and a modulation of pro-inflammatory cytokine release.

CONCLUSIONS

Administration of DHEA either given before or after the development of clinical apparent septic symptoms reliably improves survival and cellular immune functions in a murine model of sepsis.

Advances in research on the role of cytokines in chronic liver diseases

Cytokines play an important role in the development of liver inflammatory injury. Various pro-inflammatory and anti-inflammatory cytokines constitute a cytokine network that mediates the development of various liver diseases. In recent years, numerous studies have been carried out on chronic liver diseases such as viral hepatitis, fatty liver, alcoholic liver disease and hepatic cirrhosis. Here, we will review the recent advances in research on the role of cytokines in chronic liver diseases and discuss future prospects in this field.