Akt pathway is required for oestrogen-mediated attenuation of lung injury in a rodent model of cerulein-induced acute pancreatitis

Three-Dimensional Airway Spheroids and Organoids for Cystic Fibrosis Research

Cystic fibrosis (CF) is an autosomal recessive multi-organ disease caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, with morbidity and mortality primacy related to the lung disease. The CFTR protein, a chloride/bicarbonate channel, is expressed at the apical side of airway epithelial cells and is mainly involved in appropriate ion and fluid transport across the epithelium. Although many animal and cellular models have been developed to study the pathophysiological consequences of the lack/dysfunction of CFTR, only the three-dimensional (3D) structures termed “spheroids” and “organoids” can enable the reconstruction of airway mucosa to model organ development, disease pathophysiology, and drug screening. Airway spheroids and organoids can be derived from different sources, including adult lungs and induced pluripotent stem cells (iPSCs), each with its advantages and limits. Here, we review the major features of airway spheroids and organoids, anticipating that their potential in the CF field has not been fully shown. Further work is mandatory to understand whether they can accomplish better outcomes than other culture conditions of airway epithelial cells for CF personalized therapies and tissue engineering aims.

Down-regulation of long non-coding RNA XIST aggravates sepsis-induced lung injury by regulating miR-16-5p

This study aims to explain the role and related mechanisms of long non-coding RNA (lncRNA) X inactive specific transcript (XIST) in sepsis-induced acute lung injury (ALI). The in vivo septic models and in vitro septic model were established. In animal models, the lung injury of the rats was evaluated after XIST was overexpressed. In cell models, the effects of XIST and microRNA (miR)-16-5p on ALI was detected by MTT assay, Western blot and ELISA. The interaction between XIST and miR-16-5p was investigated by bioinformatics analysis, dual-luciferase reporter assay, RIP assay and RNA pull-down assay. We found that XIST expression was down-regulated in lung tissues of septic rats and lipopolysaccharide-stimulated cells, while the expression of miR-16-5p was up-regulated. Down-regulation of XIST significantly promoted pulmonary edema, increased the levels of TNF-α, IL-1β and malondialdehyde, inhibited the cell viability and decreased the level of superoxide dismutase. Mechanistically, it was confirmed that XIST could sponge miR-16-5p, and thus repress its expression, and the transfection of miR-16-5p mimics could reverse the effects of XIST over-expression in the cell model. Collectively, it is concluded that XIST reduces sepsis-induced ALI via regulating miR-16-5p.

Sex Differences in the Exocrine Pancreas and Associated Diseases

Differences in pancreatic anatomy, size, and function exist in men and women. The anatomical differences could contribute to the increase in complications associated with pancreatic surgery in women. Although diagnostic criteria for pancreatitis are the same in men and women, major sex differences in etiology are reported. Alcohol and tobacco predominate in men, whereas idiopathic and obstructive etiologies predominate in women. Circulating levels of estrogens, progesterone, and androgens contribute significantly to overall health outcomes; premenopausal women have lower prevalence of cardiovascular and pancreatic diseases suggesting protective effects of estrogens, whereas androgens promote growth of normal and cancerous cells. Sex chromosomes and gonadal and nongonadal hormones together determine an individual's sex, which is distinct from gender or gender identity. Human pancreatic disease etiology, outcomes, and sex-specific mechanisms are largely unknown. In rodents of both sexes, glucocorticoids and estrogens from the adrenal glands influence pancreatic secretion and acinar cell zymogen granule numbers. Lack of corticotropin-releasing factor receptor 2 function, a G protein-coupled receptor whose expression is regulated by both estrogens and glucocorticoids, causes sex-specific changes in pancreatic histopathology, zymogen granule numbers, and endoplasmic reticulum ultrastructure changes in acute pancreatitis model. Here, we review existing literature on sex differences in the normal exocrine pancreas and mechanisms that operate at homeostasis and diseased states in both sexes. Finally, we review pregnancy-related pancreatic diseases and discuss the effects of sex differences on proposed treatments in pancreatic disease.

Interplay between estrogen and Stat3/NF-κB-driven immunomodulation in lung cancer

K-ras mutant lung adenocarcinoma (LUAD) is the most common type of lung cancer, displays abysmal prognosis and is tightly linked to tumor-promoting inflammation, which is increasingly recognized as a target for therapeutic intervention. We have recently shown a gender-specific role for epithelial Stat3 signaling in the pathogenesis of K-ras mutant LUAD. The absence of epithelial Stat3 in male K-ras mutant mice (LR/Stat3Δ/Δ mice) promoted tumorigenesis and induced a nuclear factor-kappaB (NF-κB)-driven pro-tumor immune response while reducing tumorigenesis and enhancing anti-tumor immunity in female counterparts. In the present study, we manipulated estrogen and NF-κB signaling to study the mechanisms underlying this intriguing gender-disparity. In LR/Stat3Δ/Δ females, estrogen deprivation by bilateral oophorectomy resulted in higher tumor burden, an induction of NF-κB-driven immunosuppressive response, and reduced anti-tumor cytotoxicity, whereas estrogen replacement reversed these changes. On the other hand, exogenous estrogen in males successfully inhibited tumorigenesis, attenuated NF-κB-driven immunosuppression and boosted anti-tumor immunity. Mechanistically, genetic targeting of epithelial NF-κB activity resulted in reduced tumorigenesis and enhanced the anti-tumor immune response in LR/Stat3Δ/Δ males, but not females. Our data suggest that estrogen exerts a context-specific anti-tumor effect through inhibiting NF-κB-driven tumor-promoting inflammation and provide insights into developing novel personalized therapeutic strategies for K-ras mutant LUAD.

Apocynin Attenuates Acute Kidney Injury and Inflammation in Rats with Acute Hypertriglyceridemic Pancreatitis

BACKGROUND

Acute hypertriglyceridemic pancreatitis (HTGP) is more likely to be severe and complicated with extrapancreatic organ injury. NOX may be involved in the occurrence and development of high fat acute pancreatitis, but the specific mechanism is not clear.

AIMS

To investigate the protective effects of apocynin, an inhibitor of NOX, on kidney injury associated with the HTGP and its potential mechanisms in a rat model.

METHODS

In this study, HTGP rat model was induced by intraperitoneal injection of P-407 and L-Arg in combination. Apocynin was given by subcutaneously injection 30 min before the model was induced. The pancreatic and renal histopathology changes were analyzed. Serum AMY, BUN, Cr levels were measured by the Automatic Biochemistry Analyzer. The expression levels of protein associated with NOX/Akt pathway in the kidney were detected. ROS level in kidney and serum was measured by DHE staining and MDA, SOD kits, respectively. Serum TNF-α and IL-6 were detected by ELISA kits.

RESULTS

In HTGP group, the levels of serum AMY, BUN, Cr, TNF- α, and IL-6 were significantly increased, and the injury of pancreas and kidney was aggravated. The levels of NOX4, NOX2, ROS, p-Akt, GSK-3β, NF-κB, and TNF-α in the kidney were detected, suggesting that NOX may regulate the activity of downstream p-Akt and GSK-3β by regulating ROS levels, thereby affecting the release of inflammatory mediators and regulating HTGP-related kidney injury. After application of apocynin, the expression of NOX4 and NOX2 and the level of ROS in the kidney were reduced, the release of inflammatory mediators decreased, and the histopathology injury of pancreas and kidney was improved obviously.

CONCLUSION

NOX may play an important role in HTGP-associated kidney injury through Akt/GSK-3β pathway. Apocynin can significantly downregulate the level of NOX and play a protective role in HTGP-related kidney injury through Akt/GSK-3β pathway.

Bone marrow-derived mesenchymal stem cells alleviate severe acute pancreatitis-induced multiple-organ injury in rats via suppression of autophagy

Patients with severe acute pancreatitis (SAP) represent a substantial challenge to medical practitioners due to the high associated rates of morbidity and mortality and a lack of satisfactory therapeutic outcomes. In a previous study, our group demonstrated that bone marrow-derived mesenchymal stem cells (BMSCs) can ameliorate SAP; however, the mechanisms of action remain to be fully understood. BMSCs were intravenously injected into SAP rats 12 h after experimental induction of SAP using sodium taurocholate (NaT). Histopathological changes and the levels of pro-inflammatory mediators were assessed by hematoxylin and eosin (H&E) staining and ELISA, respectively. Autophagy levels were assessed using qRT-PCR, western blotting, immunohistochemistry, immunofluorescence, and transmission electron microscopy. AR42J cells and human umbilical vein endothelial cells (HUVECs) were administered BMSC-conditioned media (BMSC-CM) after NaT treatment, and cell viability was measured using a Cell Counting Kit-8 (CCK-8) and flow cytometry. In vivo, BMSCs effectively reduced multiple systematic inflammatory responses, suppressed the activation of autophagy, and improved intestinal dysfunction. In vitro, BMSC-CM significantly improved the viability of injured cells, promoted angiogenesis, and decreased autophagy. We therefore propose that the administration of BMSCs alleviates SAP-induced multiple organ injury by inhibiting autophagy.

Melatonin Attenuates Acute Pancreatitis-Induced Liver Damage Through Akt-Dependent PPAR-γ Pathway

BACKGROUND

Despite melatonin treatment diminishes inflammatory mediator production and improves organ injury after acute pancreatitis (AP), the mechanisms remain unknown. This study explores whether melatonin improves liver damage after AP through protein kinase B (Akt)-dependent peroxisome proliferator activated receptor (PPAR)-γ pathway.

METHODS

Male Sprague-Dawley rats were subjected to cerulein-induced AP. Animals were treated with vehicle, melatonin, and melatonin plus phosphoinositide 3-kinase (PI3K)/Akt inhibitor wortmannin 1 h following the onset of AP. Various indicators and targeted proteins were checked at 8 h in the sham and AP groups.

RESULTS

At 8 h after AP, serum alanine aminotransferase/aspartate aminotransferase levels, histopathology score of hepatic injury, liver myeloperoxidase activity, and proinflammatory cytokine production were significantly increased and liver tissue adenosine triphosphate concentration was lower compared with shams. AP resulted in a marked decrease in liver Akt phosphorylation and PPAR-γ expression in comparison with the shams (relative density, 0.442 ± 0.037 versus. 1.098 ± 0.069 and 0.390 ± 0.041 versus ± 1.080 0.063, respectively). Melatonin normalized AP-induced reduction in liver tissue Akt activation (1.098 ± 0.054) and PPAR-γ expression (1.145 ± 0.083) as well as attenuated the increase in liver injury markers and proinflammatory mediator levels, which was abolished by coadministration of wortmannin.

CONCLUSIONS

Collectively, our findings suggest that melatonin improves AP-induced liver damage in rats, at least in part, via Akt-dependent PPAR-γ pathway.

17β-Estradiol protects against lung injuries after brain death in male rats

BACKGROUND

Brain death elicits microvascular dysfunction and inflammation, and thereby compromises lung viability for transplantation. As 17β-estradiol was shown to be anti-inflammatory and vascular protective, we investigated its effects on lung injury after brain death in male rats.

METHODS

Wistar rats were assigned to: sham-operation by trepanation only (SH, n = 7); brain death (BD, n = 7); administration of 17β-estradiol (280 μg/kg, iv) at 60 minutes after brain death (BD-E2, n = 7). Experiments were performed 180 minutes thereafter. Histopathological changes in the lung were evaluated by histomorphometry. Gene expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and endothelin-1 was measured by real-time polymerase chain reaction. Protein expression of NO synthases, endothelin-1, platelet endothelial cell adhesion molecule-1 (PECAM-1), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), BCL-2, and caspase 3 was assessed by immunohistochemistry. Cytokines were quantified by enzyme-linked immunosorbent assay.

RESULTS

Treatment with 17β-estradiol after brain death decreased lung edema and hemorrhage (p < 0.0001), and serum levels of cytokine-induced neutrophil chemoattractant-1 (CINC-1; p = 0.0020). iNOS (p < 0.0001) and VCAM-1 (p < 0.0001) also diminished at protein levels, while eNOS accumulated (p = 0.0002). However, gene expression of iNOS, eNOS, and endothelin-1 was comparable among groups, as was protein expression of endothelin-1, ICAM-1, BCL-2, and caspase 3.

CONCLUSIONS

17β-Estradiol effectively reduces lung injury in brain-dead rats mainly due to its ability to regulate NO synthases. Thus, the drug may improve lung viability for transplantation.

Glucocorticoids, Sex Hormones, and Immunity

Glucocorticoid hormones regulate essential body functions in mammals, control cell metabolism, growth, differentiation, and apoptosis. Importantly, they are potent suppressors of inflammation, and multiple immune-modulatory mechanisms involving leukocyte apoptosis, differentiation, and cytokine production have been described. Due to their potent anti-inflammatory and immune-suppressive activity, synthetic glucocorticoids (GCs) are the most prescribed drugs used for treatment of autoimmune and inflammatory diseases. It is long been noted that males and females exhibit differences in the prevalence in several autoimmune diseases (AD). This can be due to the role of sexual hormones in regulation of the immune responses, acting through their endogenous nuclear receptors to mediate gene expression and generate unique gender-specific cellular environments. Given the fact that GCs are the primary physiological anti-inflammatory hormones, and that sex hormones may also exert immune-modulatory functions, the link between GCs and sex hormones may exist. Understanding the nature of this possible crosstalk is important to unravel the reason of sexual disparity in AD and to carefully prescribe these drugs for the treatment of inflammatory diseases. In this review, we discuss similarities and differences between the effects of sex hormones and GCs on the immune system, to highlight possible axes of functional interaction.

Pathogenic mechanisms of pancreatitis

Pancreatitis is inflammation of pancreas and caused by a number of factors including pancreatic duct obstruction, alcoholism, and mutation in the cationic trypsinogen gene. Pancreatitis is represented as acute pancreatitis with acute inflammatory responses and; chronic pancreatitis characterized by marked stroma formation with a high number of infiltrating granulocytes (such as neutrophils, eosinophils), monocytes, macrophages and pancreatic stellate cells (PSCs). These inflammatory cells are known to play a central role in initiating and promoting inflammation including pancreatic fibrosis, i.e., a major risk factor for pancreatic cancer. A number of inflammatory cytokines are known to involve in promoting pancreatic pathogenesis that lead pancreatic fibrosis. Pancreatic fibrosis is a dynamic phenomenon that requires an intricate network of several autocrine and paracrine signaling pathways. In this review, we have provided the details of various cytokines and molecular mechanistic pathways (i.e., Transforming growth factor-β/SMAD, mitogen-activated protein kinases, Rho kinase, Janus kinase/signal transducers and activators, and phosphatidylinositol 3 kinase) that have a critical role in the activation of PSCs to promote chronic pancreatitis and trigger the phenomenon of pancreatic fibrogenesis. In this review of literature, we discuss the involvement of several pro-inflammatory and anti-inflammatory cytokines, such as in interleukin (IL)-1, IL-1β, IL-6, IL-8 IL-10, IL-18, IL-33 and tumor necrosis factor-α, in the pathogenesis of disease. Our review also highlights the significance of several experimental animal models that have an important role in dissecting the mechanistic pathways operating in the development of chronic pancreatitis, including pancreatic fibrosis. Additionally, we provided several intermediary molecules that are involved in major signaling pathways that might provide target molecules for future therapeutic treatment strategies for pancreatic pathogenesis.

Role of phosphoinositide-3 kinase signaling pathways in pathogenesis of acute pancreatitis

Acute pancreatitis (AP) as a common acute disease poses a great threat to people's health. According to statistics, about one-fifth of cases develop acute respiratory distress syndrome and multiple organ dysfunction, which result in high mortality. The early understanding of the pathogenesis of this disease is limited to an inflammatory response resulting in autodigestion, edema, hemorrhage and necrosis of pancreatic tissue after the abnormal activation of trypsin. In recent years, researchers have focused their research on the role of immune inflammatory response in the pathogenesis of AP. Here we discuss the relationship between the immune inflammation and PI3K signaling pathways in AP.

BML-111 attenuates acute lung injury in endotoxemic mice

BACKGROUND

BML-111 is a lipoxin receptor agonist that has protective effects in various lung injury models. We tried to elucidate whether BML-111 could mitigate lung injury in a mouse model of endotoxemia and endothelial hyperpermeability in vitro.

METHODS

The effect of BML-111 on lung injury was evaluated using C57BL/6 mice and human umbilical vein endothelial cells (HUVECs). Male C57BL/6 mice were intraperitoneally injected with normal saline, BML-111, and/or the lipoxin receptor antagonist Boc-2. Then, either lipopolysaccharide (LPS) or normal saline was given intraperitoneally. Lung injury was assessed by a pathohistologic examination for neutrophil infiltration, pulmonary endothelial permeability, and inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid. HUVECs were treated with or without BML-111 before incubation with LPS for 24 h. Boc-2 was also tested as a novel inhibitor of BML-111. A Transwell assay was used to evaluate the permeability of HUVECs. Junction protein expression was also assessed.

RESULTS

BML-111 significantly improved the mouse survival rate, reduced body weight loss, attenuated the pulmonary pathologic changes, inhibited neutrophil infiltration and proinflammatory cytokine production, and mitigated endothelial hyperpermeability. The decreased expression of junction proteins induced by LPS in lung tissue and endothelial cells were upregulated by BML-111. In addition, BML-111 inhibited the activation of the Akt, ERK1/2, and p38 MAPK signaling pathways. However, the beneficial effects of BML-111 were abolished by Boc-2.

CONCLUSIONS

BML-111 attenuated lung injury in endotoxemic mice and mitigated endothelial hyperpermeability by upregulating the expression of junction proteins.

Chloroquine rescues A549 cells from paraquat-induced death

Paraquat (PQ) is a widely used herbicide associated with a high mortality rate, yet, there are no effective treatments for PQ poisoning. PQ may damage alveolar type II cells leading to moderate to severe acute respiratory distress syndrome (ARDS). The present study was undertaken to show that PQ causes alveolar type II (A549) cell death and to evaluate whether chloroquine (CQ) can protect A549 cells against PQ-induced cell death. The results showed that high concentrations of PQ resulted in toxicity, as indicated by a decrease in cell viability. More importantly, for the first time, CQ was found to improve cell viability of PQ treated A549 cells. Moreover, our data demonstrated that CQ increased lysosome-associated membrane protein-1, lysosome-associated membrane protein-2 and light chain-3 expressions, suggesting that the mechanism by which CQ rescues PQ-induced cytotoxicity may be through protection of the lysosomal membrane or up-regulation of autophagy. In conclusion, our study indicates that CQ may be used as a potential drug to rescue PQ-induced ARDS.

17β-estradiol suppresses lipopolysaccharide-induced acute lung injury through PI3K/Akt/SGK1 mediated up-regulation of epithelial sodium channel (ENaC) in vivo and in vitro

Background

17β-estradiol can suppress acute lung injury (ALI) and regulate alveolar epithelial sodium channel (ENaC). However the relationship between these two functions remains unclear. This study is conducted to assess the role of ENaC and the PI3K/Akt/SGK1 signaling pathway in 17β-estradiol therapy in attenuating LPS-induced ALI.

Methods

ALI was induced in C57BL/J male mice by intratracheal administration of lipopolysaccharide (LPS). Concurrent with LPS administration, 17β-estradiol or sterile saline was administered to ALI model with or without the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin. The lung histological changes, inflammatory mediators in bronchoalveolar lavage fluid (BALF), wet/dry weight ratio (W/D) and alveolar fluid clearance (AFC) were measured 4 hours after LPS challenge in vivo. For in vitro studies, LPS-challenged MLE-12 cells were pre-incubated with or without wortmannin for 30 minutes prior to 17β-estradiol treatment. Expression of ENaC subunits was assessed by reverse transcriptase PCR, western blot, cell surface biotinylation, and immunohistochemistry. The levels of phosphorylated Akt and SGK1 in lung tissue and lung cell lines were investigated by western blot.

Results

17β-estradiol suppressed LPS-mediated ALI in mice by diminishing inflammatory mediators and enhancing AFC. 17β-estradiol promoted the expression and surface abundance of α-ENaC, and increased the levels of phosphorylated-Akt and phosphorylated-SGK1 following LPS challenge. This induction was abolished by the PI3K inhibitor wortmannin in vivo and in vitro.

Conclusion

17β-estradiol attenuates LPS-induced ALI not only by repressing inflammation, but also by reducing pulmonary edema via elevation of α-ENaC expression and membrane abundance. These effects were mediated, at least partially, via activation of the PI3K/Akt/SGK1 signaling pathway.

Role of phosphoinositide 3-kinase in the pathogenesis of acute pancreatitis

A large body of experimental and clinical data supports the notion that inflammation in acute pancreatitis has a crucial role in the pathogenesis of local and systemic damage and is a major determinant of clinical severity. Thus, research has recently focused on molecules that can regulate the inflammatory processes, such as phosphoinositide 3-kinases (PI3Ks), a family of lipid and protein kinases involved in intracellular signal transduction. Studies using genetic ablation or pharmacologic inhibitors of different PI3K isoforms, in particular the class I PI3Kδ and PI3Kγ, have contributed to a greater understanding of the roles of these kinases in the modulation of inflammatory and immune responses. Recent data suggest that PI3Ks are also involved in the pathogenesis of acute pancreatitis. Activation of the PI3K signaling pathway, and in particular of the class IB PI3Kγ isoform, has a significant role in those events which are necessary for the initiation of acute pancreatic injury, namely calcium signaling alteration, trypsinogen activation, and nuclear factor-κB transcription. Moreover, PI3Kγ is instrumental in modulating acinar cell apoptosis, and regulating local neutrophil infiltration and systemic inflammatory responses during the course of experimental acute pancreatitis. The availability of PI3K inhibitors selective for specific isoforms may provide new valuable therapeutic strategies to improve the clinical course of this disease. This article presents a brief summary of PI3K structure and function, and highlights recent advances that implicate PI3Ks in the pathogenesis of acute pancreatitis.

Effects of phosphoinositide 3-kinase on protease-induced acute and chronic lung inflammation, remodeling, and emphysema in rats

BACKGROUND

Phosphoinositide 3-kinase (PI3K) plays an important role in tissue inflammatory reactions and fibrotic processes. The objective of this study was to evaluate the potential mechanism and therapeutic effects of PI3K inhibitor on pancreatic elastase (PE)-induced acute and chronic lung inflammation, edema, and injury.

METHODS

Rats were terminated at 7 or 28 days after an intratracheal challenge with PE and intranasal instillation with a PI3K inhibitor, SHBM1009. Alterations of airway epithelial cells and myofibroblasts were studied in vitro.

MEASUREMENTS

Lung inflammation, edema, and injury; emphysema; and tissue remodeling were measured after PE instillation with or without treatment with PI3K inhibitor and budesonide. Cellular biologic functions were monitored.

RESULTS

SHBM1009 could prevent PE-induced acute lung inflammation, edema, and injury, and chronic lung inflammation, remodeling, and emphysema. Different patterns of inhibitory effects of SHBM1009 and BEZ235, a dual PI3K/mechanistic target of rapamycin inhibitor, on PE-challenged epithelial cells were observed. PE per se reduced epithelial cell proliferation and stability through the inhibition of cell division rather than promoting cell death, in dose- and time-dependent patterns. Effects of PI3K inhibitors on cells were associated with the severity of PE challenges.

CONCLUSIONS

PI3K plays a critical role in the development of acute and chronic lung injury, including the process of tissue remodeling and emphysema. PI3K inhibitors could be new therapeutic alternatives for chronic lung diseases.

Effect of PI3K inhibitor wortmannin on cytokine levels and pancreatic histopathological scores in rats with severe acute pancreatitis

AIM: To investigate the effect of the PI3K/Akt signaling transduction pathway inhibitor wortmannin on the levels of cytokines [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6] and pancreatic histopathological changes in rats with severe acute pancreatitis (SAP).

METHODS: Sixty male Sprague-Dawley (SD) rats were randomly divided into five groups, including SAP group, sham operation group, normal saline group, DMSO control group, and wortmannin group. The modified Aho's method was used to reproduce the SAP model. The rats were sacrificed 3 and 6 h after treatment. The levels of inflammatory cytokines TNF-α, IL-1β and IL-6 in serum were determined by ELISA. Transcription levels of these inflammatory cytokines in pancreatic tissue were determined by real-time PCR. In addition, the amount of ascites, the activities of serum amylase and ascites amylase, and the pathological scores of pancreatic tissue were also measured.

RESULTS: At 3 and 6 h after treatment, all parameters tested, including the amount of ascites, the levels of serum and ascites amylase, the pathological scores of pancreatic tissue, serum levels of TNF-α, IL-1β and IL-6, and the transcription levels of TNF-α, IL-1β and IL-6 mRNAs in the pancreatic tissue, in the SAP group and DMSO group were significantly higher than those in the normal saline group and sham operation group (all P < 0.05). Compared to the SAP group and DMSO group, the above parameters decreased significantly in the wortmannin group (all P < 0.05).

CONCLUSION: Wortmannin exerts a protective effect against SAP possibly by down-regulating the levels of TNF-α, IL-1β and IL-6 and reducing pathological injury of pancreatic tissue in rats.

Role of Akt/HO-1 pathway in estrogen-mediated attenuation of trauma-hemorrhage-induced lung injury

BACKGROUND

Despite advances in intensive care medicines, hemorrhagic shock leading to multiple organ failure remains the major causes of death in the injured host. Although studies have shown that 17β-estradiol (E2) prevents trauma-hemorrhage-induced lung damage, it remains unknown whether protein kinase B (Akt)/heme oxygenase (HO)-1 plays any role in E2-mediated lung protection after trauma-hemorrhage.

MATERIALS AND METHODS

After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure ∼40 mm Hg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E2 (1 kg/mg), E2 plus phosphoinositide 3-kinase inhibitor LY294002 (5 mg/kg), or LY294002. At 2 h after trauma-hemorrhage or sham operation, lung tissue myeloperoxidase activity, wet-to-dry-weight ratio, inflammatory mediators, and apoptosis were measured. Lung Akt, HO-1, and cleaved caspase-3 protein levels were also determined.

RESULTS

E2 attenuated the trauma-hemorrhage-induced increase in lung myeloperoxidase activity, edema formation, inflammatory mediator levels, and apoptosis, which was blocked by co-administration of LY294002. Administration of E2 normalized lung Akt phosphorylation and further increased HO-1 expression and decreased cleaved caspase-3 levels after trauma-hemorrhage. Co-administration of LY294002 prevented the E2-mediated attenuation of shock-induced lung injury.

CONCLUSIONS

Our results collectively suggest that Akt-dependent HO-1 upregulation may play a critical role in E2-meditated lung protection after trauma-hemorrhage.

Melatonin prevents hemorrhagic shock-induced liver injury in rats through an Akt-dependent HO-1 pathway

Although melatonin treatment following trauma-hemorrhage or ischemic reperfusion prevents organs from dysfunction and injury, the precise mechanism remains unknown. This study tested whether melatonin prevents liver injury following trauma-hemorrhage involved the protein kinase B (Akt)-dependent heme oxygenase (HO)-1 pathway. After a 5-cm midline laparotomy, male rats underwent hemorrhagic shock (mean blood pressure approximately 40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, melatonin (2 mg/kg), or melatonin plus phosphoinositide 3-kinase (PI3K) inhibitor wortmannin (1 mg/kg). At 2 hr after trauma-hemorrhage, the liver tissue myeloperoxidase activity, malondialdehyde, adenosine triphosphate, serum alanine aminotransferase, and aspartate aminotransferase levels were significantly increased compared with sham-operated control. Trauma-hemorrhage resulted in a significant decrease in the Akt activation in comparison with the shams (relative density, 0.526 ± 0.031 versus 1.012 ± 0.066). Administration of melatonin following trauma-hemorrhage normalized liver Akt phosphorylation (0.993 ± 0.061), further increased mammalian target of rapamycin (mTOR) activation (5.263 ± 0.338 versus 2.556 ± 0.225) and HO-1 expression (5.285 ± 0.325 versus 2.546 ± 0.262), and reduced cleaved caspase-3 levels (2.155 ± 0.297 versus 5.166 ± 0.309). Coadministration of wortmannin abolished the melatonin-mediated attenuation of the shock-induced liver injury markers. Our results collectively suggest that melatonin prevents hemorrhagic shock-induced liver injury in rats through an Akt-dependent HO-1 pathway.

Protein kinases - new targets for treatment of acute pancreatitis

Acute pancreatitis (AP) is a common acute abdomen. Although most cases of AP are self-limited, severe AP is still associated with a higher mortality rate. Protein kinases are involved in almost all intracellular signal transduction pathways, and AP-related protein kinases may be good targets for treatment of AP. Numerous studies have investigated the protein kinases and their specific inhibitors involved in AP in recent years. Here we utilized the data mining method to summarize protein kinases and kinase inhibitors that correlate with AP and highlight several important protein kinases, with an aim to provide new clues to the treatment of AP.

Preventive and therapeutic effects of phosphoinositide 3-kinase inhibitors on acute lung injury

BACKGROUND

Phosphoinositide 3-kinases (PI3Ks) are involved in a number of biologic responses. Recent preclinical studies demonstrated that the PI3K-dominant signal pathway could play an important role in the development of acute lung injury, although the mechanism remains unclear.

METHODS

CD-1 mice were administered different PI3K inhibitors either intranasally or intragastrically once a day for 3 days before intratracheal instillation of lipopolysaccharide at 4 h and 24 h. Effects of SHBM1009 on lipopolysaccharide-induced capillary permeability, leukocyte distribution and activation, and epithelial cell function were measured. Therapeutic effects of SHBM1009 on pancreatic elastase-induced lung injury were evaluated in rats.

RESULTS

The data demonstrated that the local delivery of PI3K inhibitors played more effective roles in the prevention of endotoxin-induced lung injury than the systemic delivery. The preventive effects of PI3K inhibitors varied most likely because of chemical properties, targeting sites, and pharmacokinetics. The local PI3K inhibitors prevented both endotoxin- and elastase-induced lung injury in mice and rats, possibly through directly inhibiting or inactivating the function of airway epithelial cells, which could not produce chemoattractant factors to activate neutrophils and macrophages.

CONCLUSIONS

PI3K may be a therapeutic target for lung injury, and local delivery of PI3K inhibitors may be one of the optimal approaches for the therapy.