Beneficial effect of cyclosporine A on traumatic hemorrhagic shock

MiR-148b Caused Liver Injury in Rats with Traumatic Hemorrhagic Shock by Inhibiting SIRT6 Expression

BACKGROUND

The purpose of this study was to investigate the role of miR- 148b in liver injury in rats with traumatic hemorrhagic shock (THS) and to elucidate its potential mechanism.

METHODS

The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum of rats were detected by enzyme-linked immune sorbent assay (ELISA), and the injury of rat liver was analyzed by hematoxylin-eosin (H&E) staining. Apoptosis of rat hepatocytes and normal rat liver cell line (BRL3A) was identified by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and flow cytometry, respectively. MiR-148b and sirtuin 6 (SIRT6) expression was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. Lactate dehydrogenase (LDH) content and cell viability were measured by commercial kits and cell counting kit-8 (CCK-8) assay, respectively. The binding sites of miR-148b and SIRT6 were predicted by the Starbase database and verified by dual luciferase reporter assay.

RESULTS

MiR-148b expression in THS rats or ischemia-reperfusion (I/R)-treated cells was higher than in the control group. Overexpression of miR-148b further promoted the effects of I/R, which enhanced the levels of ALT, AST and LDH, cell apoptosis of liver tissue or BRL3A cells and decreased the expression of SITR6. Besides, miR-148b negatively correlated with SIRT6, and upregulated the expression of SIRT6 could partly reverse the effect of miR-148b.

CONCLUSION

Hepatocyte injury induced by I/R was achieved by regulating miR-148b /SIRT6 axis.

Pathophysiology of Hemorrhage as It Relates to the Warfighter

Saving lives of wounded military Warfighters often depends on the ability to resolve or mitigate the pathophysiology of hemorrhage, specifically diminished oxygen delivery to vital organs that leads to multi-organ failure and death. However, caring for hemorrhaging patients on the battlefield presents unique challenges that extend beyond applying a tourniquet and giving a blood transfusion, especially when battlefield care must be provided for a prolonged period. This review will describe these challenges and potential strategies for treating hemorrhage on the battlefield in a prolonged casualty care situation.

Sirtuins and Sepsis: Cross Talk between Redox and Epigenetic Pathways

Sepsis and septic shock are the leading causes of death among hospitalized patients in the US. The immune response in sepsis transitions from a pro-inflammatory and pro-oxidant hyper-inflammation to an anti-inflammatory and cytoprotective hypo-inflammatory phase. While 1/3rd sepsis-related deaths occur during hyper-, a vast majority of sepsis-mortality occurs during the hypo-inflammation. Hyper-inflammation is cytotoxic for the immune cells and cannot be sustained. As a compensatory mechanism, the immune cells transition from cytotoxic hyper-inflammation to a cytoprotective hypo-inflammation with anti-inflammatory/immunosuppressive phase. However, the hypo-inflammation is associated with an inability to clear invading pathogens, leaving the host susceptible to secondary infections. Thus, the maladaptive immune response leads to a marked departure from homeostasis during sepsis-phases. The transition from hyper- to hypo-inflammation occurs via epigenetic programming. Sirtuins, a highly conserved family of histone deacetylators and guardians of homeostasis, are integral to the epigenetic programming in sepsis. Through their anti-inflammatory and anti-oxidant properties, the sirtuins modulate the immune response in sepsis. We review the role of sirtuins in orchestrating the interplay between the oxidative stress and epigenetic programming during sepsis.

Mitochondrial Drp1 recognizes and induces excessive mPTP opening after hypoxia through BAX-PiC and LRRK2-HK2

Mitochondrial mass imbalance is one of the key causes of cardiovascular dysfunction after hypoxia. The activation of dynamin-related protein 1 (Drp1), as well as its mitochondrial translocation, play important roles in the changes of both mitochondrial morphology and mitochondrial functions after hypoxia. However, in addition to mediating mitochondrial fission, whether Drp1 has other regulatory roles in mitochondrial homeostasis after mitochondrial translocation is unknown. In this study, we performed a series of interaction and colocalization assays and found that, after mitochondrial translocation, Drp1 may promote the excessive opening of the mitochondrial permeability transition pore (mPTP) after hypoxia. Firstly, mitochondrial Drp1 maximumly recognizes mPTP channels by binding Bcl-2-associated X protein (BAX) and a phosphate carrier protein (PiC) in the mPTP. Then, leucine-rich repeat serine/threonine-protein kinase 2 (LRRK2) is recruited, whose kinase activity is inhibited by direct binding with mitochondrial Drp1 after hypoxia. Subsequently, the mPTP-related protein hexokinase 2 (HK2) is inactivated at Thr-473 and dissociates from the mitochondrial membrane, ultimately causing structural disruption and overopening of mPTP, which aggravates mitochondrial and cellular dysfunction after hypoxia. Thus, our study interprets the dual direct regulation of mitochondrial Drp1 on mitochondrial morphology and functions after hypoxia and proposes a new mitochondrial fission-independent mechanism for the role of Drp1 after its translocation in hypoxic injury.

Protective Effect of Crocin on Liver Function and Survival in Rats With Traumatic Hemorrhagic Shock

BACKGROUND

This study investigated the underlying mechanism of crocin in protecting rats with traumatic hemorrhagic shock (THS) from liver injury.

MATERIALS AND METHODS

Eighty Sprague Dawley rats were randomly divided into four groups (n = 20), namely, Sham group, THS group, crocin group, and Sodium Acetate Ringer group. A rat model of THS was induced by hemorrhage from the left femur fracture. The effects of crocin on hemodynamics, cardiac output, blood gas, animal survival rate, and liver function in the rats with THS were determined, and its relationship with oxidative stress was also explored.

RESULTS

Crocin significantly improved the survival rate, hemodynamic parameters, increased tissue blood flow, and promoted the liver function of the THS rats. Further results indicated that crocin significantly inhibited oxidative stress in serum and liver tissue of THS rats, with increased levels of superoxide dismutase, catalase, and glutathione, and also reduced levels of malondialdehyde and myeloperoxidase levels. In addition, crocin greatly increased nuclear factor erythroid 2-related factor 2/heme oxygenase-1 level in liver tissues of THS rats.

CONCLUSIONS

The protective mechanism of crocin on the liver of THS rats may be attributed to its abilities to stabilize hemodynamics, improve cardiac output and blood gas, increase antioxidant enzyme activity, reduce serum liver enzyme levels, and promote nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway, thereby reducing oxidative stress.

Insights into the modulatory role of cyclosporine A and its research advances in acute inflammation

Cyclosporine A(CsA), a classic immunosuppressant, is mainly applied for solid organ transplantation and some autoimmune diseases by suppressing T lymphocytes. Early studies showed that the application of CsA is primarily focused on chronic but not acute inflammation, nevertheless, increasing evidence supporting a role for CsA in acute inflammation, although most of proofs come from experimental models. It has long been known to us that the nuclear factor of activated T cells (NFAT) is the target of CsA to regulate T lymphocytes. However, NFAT also contributes to the regulation of innate immune cells, thus, CsA can not only target lymphocytes but also innate immune cells such as monocytes/macrophages, dendritic cells and neutrophils, which provides a basis for CsA to act on acute inflammation. Moreover, some other pathophysiological events in acute inflammation such as decreased vascular activity, mitochondrial dysfunction and endogenous cell apoptosis can also be alleviated by CsA. There being a moderate successes in the application of CsA for experimental acute inflammation such as sepsis, trauma/hemorrhagic shock and ischemic/reperfusion injury, yet data of the clinical treatment is not clear. In this review, we will critically analyze the existing hypotheses, summarize the application of CsA and its possible mechanisms in various acute inflammation over the past few decades, hope to provide some clues for the clinical treatment of acute inflammation.

The Beneficial Effect of HES on Vascular Permeability and Its Relationship With Endothelial Glycocalyx and Intercellular Junction After Hemorrhagic Shock

Background

Vascular leakage is a common complication of hemorrhagic shock. Endothelial glycocalyx plays a crucial role in the protection of vascular endothelial barrier function. Hydroxyethyl starch (HES) is a commonly used resuscitation fluid for hemorrhagic shock. However, whether the protective effect of HES on vascular permeability after hemorrhagic shock is associated with the endothelial glycocalyx is unclear.

Methods

Using hemorrhagic shock rat model and hypoxia treated vascular endothelial cells (VECs), effects of HES (130/0.4) on pulmonary vascular permeability and the relationship to endothelial glycocalyx were observed.

Results

Pulmonary vascular permeability was significantly increased after hemorrhagic shock, as evidenced by the increased permeability of pulmonary vessels to albumin-fluorescein isothiocyanate conjugate (FITC-BSA) and Evans blue, the decreased transendothelial electrical resistance of VECs and the increased transmittance of FITC-BSA. The structure of the endothelial glycocalyx was destroyed, showing a decrease in thickness. The expression of heparan sulfate, hyaluronic acid, and chondroitin sulfate, the components of the endothelial glycocalyx, was significantly decreased. HES (130/0.4) significantly improved the vascular barrier function, recovered the thickness and the expression of components of the endothelial glycocalyx by down-regulating the expression of heparinase, hyaluronidase, and neuraminidase, and meanwhile increased the expression of intercellular junction proteins ZO-1, occludin, and VE-cadherin. Degradation of endothelial glycocalyx with degrading enzyme (heparinase, hyaluronidase, and neuraminidase) abolished the beneficial effect of HES on vascular permeability, but had no significant effect on the recovery of the expression of endothelial intercellular junction proteins induced by HES (130/0.4). HES (130/0.4) decreased the expression of cleaved-caspase-3 induced by hemorrhagic shock.

Conclusions

HES (130/0.4) has protective effect on vascular barrier function after hemorrgic shock.The mechanism is mainly related to the protective effect of HES on endothelial glycocalyx and intercellular junction proteins. The protective effect of HES on endothelial glycocalyx was associated with the down-regulated expression of heparinase, hyaluronidase, and neuraminidase. HES (130/0.4) had an anti-apoptotic effect in hemorrhagic shock.

Drp1 regulates mitochondrial dysfunction and dysregulated metabolism in ischemic injury via Clec16a-, BAX-, and GSH- pathways

The adaptation of mitochondrial homeostasis to ischemic injury is not fully understood. Here, we studied the role of dynamin-related protein 1 (Drp1) in this process. We found that mitochondrial morphology was altered in the early stage of ischemic injury while mitochondrial dysfunction occurred in the late stage of ischemia. Drp1 appeared to inhibit mitophagy by upregulating mito-Clec16a, which suppressed mito-Parkin recruitment and subsequently impaired the formation of autophagosomes in vascular tissues after ischemic injury. Moreover, ischemia-induced Drp1 activation enhanced apoptosis through inducing mitochondrial translocation of BAX and thereby increasing release of Cytochrome C to activate caspase-3/-9 signalling. Furthermore, Drp1 mediated metabolic disorders and inhibited the levels of mitochondrial glutathione to impair free radical scavenging, leading to further increases in ROS and the exacerbation of mitochondrial dysfunction after ischemic injury. Together, our data suggest a critical role for Drp1 in ischemic injury.

miRNA-mRNA crosstalk in myocardial ischemia induced by calcified aortic valve stenosis

Aortic valve stenosis is the most common cause of morbidity and mortality in valvular heart disease in aged people. Both microRNA (miRNA) and mRNA are potential targets for the diagnosis and therapeutic intervention of myocardial ischemia induced by calcified aortic valve stenosis (CAVS), with unclear mechanisms. Here, 3 gene expression profiles of 47 male participants were applied to generate shared differentially expressed genes (DEGs) with significant major biological functions. Moreover, 20 hub genes were generated by a Weighted Genes Co-Expression Network Analysis (WGCNA) and were cross-linked to miRNA based on miRanda/miRwalk2 databases. Integrated miRNA/mRNA analysis identified several novel miRNAs and targeted genes as diagnostic/prognostic biomarkers or therapeutic targets in CAVS patients. In addition, the clinical data suggested that myocardial hypertrophy and myocardial ischemia in CAVS patients are likely associated with hub genes and the upstream regulatory miRNAs. Together, our data provide evidence that miRNAs and their targeted genes play an important role in the pathogenesis of myocardial hypertrophy and ischemia in patients with CAVS.

Kawasaki disease shock syndrome: Unique and severe subtype of Kawasaki disease

BACKGROUND

Kawasaki disease shock syndrome (KDSS) is an uncommon presentation of Kawasaki disease (KD). KDSS has been associated with more severe markers of inflammation, coronary abnormalities and i.v. immunoglobulin (IVIG) resistance.

METHODS

A retrospective, descriptive study of children with KDSS in two hospitals was performed. Relevant articles about KD and shock were collected, and demographic data, clinical presentation, laboratory variables, echocardiogram findings, treatment and special features were analyzed when available. Twelve patients diagnosed with KDSS were retrospectively reviewed from two centers in Mexico, along with 91 additional cases from the literature.

RESULTS

Seventy-two patients presented with complete KD (69.9%), and 30.1% (31/103) had unusual KD manifestations. The most frequent diagnosis at the time of admission was toxic shock syndrome (TSS; n = 20). Sixteen of the 20 had coronary artery abnormalities. Overall, abnormalities in the coronary arteries were documented in 65% of the patients. The mortality rate was 6.8%.

CONCLUSION

The presence of coronary aneurysms was significantly and positively correlated with male gender, IVIG resistance, inotrope treatment, cardiac failure, abdominal pain and neurological symptoms. IVIG-resistant patients had higher neutrophil : lymphocyte ratio. Abdominal symptoms, hypoalbuminemia and elevated C-reactive protein were present in almost all of the patients. Multisystem involvement with atypical presentation in KDSS is frequent. An important differential diagnosis is TSS. Mechanical ventilation, gastrointestinal and neurological symptoms were associated with IVIG resistance and the presence of coronary aneurysms. The first line of treatment includes IVIG and pulse corticosteroids; in severe cases, infliximab, anakinra, cyclosporine or plasmapheresis are alternative treatment options.

Where's the Leak in Vascular Barriers? A Review

Edema is typically presented as a secondary effect from injury, illness, disease, or medication, and its impact on patient wellness is nested within the underlying etiology. Therefore, it is often thought of more as an amplifier to current preexisting conditions. Edema, however, can be an independent risk factor for patient deterioration. Improper management of edema is costly not only to the patient, but also to treatment and care facilities, as mismanagement of edema results in increased lengths of hospital stay. Direct tissue trauma, disease, or inappropriate resuscitation and/or ventilation strategies result in edema formation through physical disruption and chemical messenger-based structural modifications of the microvascular barrier. Derangements in microvascular barrier function limit tissue oxygenation, nutrient flow, and cellular waste removal. Recent studies have sought to elucidate cellular signaling and structural alterations that result in vascular hyperpermeability in a variety of critical care conditions to include hemorrhage, burn trauma, and sepsis. These studies and many others have highlighted how multiple mechanisms alter paracellular and/or transcellular pathways promoting hyperpermeability. Roles for endothelial glycocalyx, extracellular matrix and basement membrane, vesiculo-vacuolar organelles, cellular junction and cytoskeletal proteins, and vascular pericytes have been described, demonstrating the complexity of microvascular barrier regulation. Understanding these basic mechanisms inside and out of microvessels aid in developing better treatment strategies to mitigate the harmful effects of excessive edema formation.

The Emerging Role of Mitochondrial Targeting in Kidney Disease

Renal disease affects millions of people worldwide, imposing an enormous financial burden for health-care systems. Recent evidence suggests that mitochondria play an important role in the pathogenesis of different forms of renal disease, including genetic defects, acute kidney injury, chronic kidney disease, aging, renal tumors, and transplant nephropathy. Renal mitochondrial abnormalities and dysfunction affect several cellular pathways, leading to increased oxidative stress, apoptosis, microvascular loss, and fibrosis, all of which compromise renal function. Over recent years, compounds that specifically target mitochondria have emerged as promising therapeutic options for patients with renal disease. Although the most compelling evidence is based on preclinical studies, several compounds are currently being tested in clinical trials. This chapter provides an overview of the involvement of mitochondrial dysfunction in renal disease and summarizes the current knowledge on mitochondria-targeted strategies to attenuate renal disease.

Resveratrol enhances vascular reactivity in mice following lipopolysaccharide challenge via the RhoA-ROCK-MLCP pathway

The aim of the present study was to identify whether sepsis-induced vascular hyporeactivity is associated with microcirculation disturbance and multiple organ injuries. The current study assessed the impact of resveratrol (Res) treatment on lipopolysaccharide (LPS) challenge mediated vascular hyporeactivity. Effects of Res treatment (30 mg/kg; i.m.) at 1 h following LPS stimulation (5 mg/kg; i.v.) on the survival time, mean arterial pressure (MAP), and maximal difference of MAP (ΔMAP) to norepinephrine (NE; 4.2 µg/kg) in mice were observed. The reactivity to gradient NE of isolated mesenteric arterioles and the association with the RhoA-RhoA kinase (ROCK)-myosin light chain phosphatase (MLCP) pathway were investigated by myography, and the signaling molecule protein levels were assessed using ELISA. Res treatment prolonged the survival time of mice subjected to LPS challenge, but did not prevent the LPS-induced hypotension and increase in ΔMAP. Res treatment and RhoA agonist U-46619 incubation prevented LPS-induced vascular hyporeactivity ex vivo, which were suppressed by incubation with ROCK inhibitor Y-27632. LPS-induced vascular hyporeactivity was not affected by the MLCP inhibitor okadaic acid incubation, but was further downregulated by the co-incubation of OA plus Y-27632. The inhibiting effect of Y-27632 on Res treatment was eradicated by incubation with U-46619. Furthermore, RhoA inhibitor C3 transferase did not significantly inhibit the enhancing role of Res treatment, which was further increased by U-46619 plus C3 transferase co-incubation. In addition, Res treatment eradicated the LPS-induced decreases in p-RhoA and p-Mypt1 levels and increases in MLCP levels. The results of the present study indicate that post-treatment of Res significantly ameliorates LPS-induced vascular hyporeactivity, which is associated with the activation of the RhoA-ROCK-MLCP pathway.

Metabolomic analysis of survival in carbohydrate pre-fed pigs subjected to shock and polytrauma

Hemorrhagic shock, a result of extensive blood loss, is a dominant factor in battlefield morbidity and mortality. Early rodent studies in hemorrhagic shock reported carbohydrate feeding prior to the induction of hemorrhagic shock decreased mortality. When repeated in our laboratory with a porcine model, carbohydrate pre-feed resulted in a 60% increase in death rate following hemorrhagic shock with trauma when compared to fasted animals (15/32 or 47% vs. 9/32 or 28%). In an attempt to explain the unexpected death rate for pre-fed animals, we further investigated the metabolic profiles of pre-fed non-survivors (n = 15) across 4 compartments (liver, muscle, serum, and urine) at specific time intervals (pre-shock, shock, and resuscitation) and compared them to pre-fed survivors (n = 17). As hypothesized, pre-fed pigs that died as a result of hemorrhage and trauma showed differences in their metabolic and physiologic profiles at all time intervals and in all compartments when compared to pre-fed survivors. Our data suggest that, although all animals were subjected to the same shock and trauma protocol, non-survivors exhibited altered carbohydrate processing as early as the pre-shock sampling point. This was evident in (for example) the higher levels of ATP and markers of greater anabolic activity in the muscle at the pre-shock time point. Based on the metabolic findings, we propose two mechanisms that connect pre-fed status to a higher death rate: (1) animals that die are more susceptible to opening of the mitochondrial permeability transition pore, a major factor in ischemia/reperfusion injury; and (2) loss of fasting-associated survival mechanisms in pre-fed animals.