Pentoxifylline Attenuates Lung Injury and Modulates Transcription Factor Activity in Hemorrhagic Shock

Activation of angiotensin II type 2 receptor attenuates lung injury of collagen-induced arthritis by alleviating endothelial cell injury and promoting Ly6Clo monocyte transition

As one of the most frequent extra-articular manifestations of rheumatoid arthritis (RA), interstitial lung disease (ILD) is still challenging due to unrevealed pathophysiological mechanism. To address this question, in the present study, we used the classical collagen-induced arthritis (CIA) mouse model to determine the related-immune mechanism of lung injury and possible pharmacological treatment for RA-ILD. At the peak of arthritis, we found CIA mice developed apparent lung injury, characterized by interstitial thickening, inflammatory cell infiltration, and lymphocyte follicle formation. Additionally, the endothelial injury occurred as the number of endothelial cells (ECs) and their CD31 expression decreased. Along with those, monocytes, predominantly Ly6C^hi monocytes with pro-inflammatory phenotype, were also increased. While in the remission period of arthritis, ECs gradually increased with retrieved CD31 expression, leading to decreased infiltrating monocytes, but boosted Ly6C^lo population. Ly6C^lo monocytes were prone to locate around damaged ECs, promoted ECs proliferation and vascular tube formation, and lessened the expression of adhesion molecules. In addition, we evaluated angiotensin II type 2 receptor (Agtr2), which has been demonstrated to be protective against lung injury, could be beneficial in RA-ILD. We found elevated Agtr2 in CIA lung tissue, and activation of Agtr2, within its specific agonist C21, alleviated the pulmonary inflammation in vivo, reduced ECs injury, and promoted monocytes conversion from Ly6C^hi to Ly6C^lo monocytes in vitro. Our data reveal a potential pathological mechanism of RA-ILD that involves ECs damage and inflammatory monocytes infiltration and provide a potential drug target, Agtr2, for RA-ILD treatment.

Pentoxifylline as a Potential Adjuvant Therapy for COVID-19: Impeding the Burden of the Cytokine Storm

The outburst of inflammatory response and hypercoagulability are among the factors contributing to increased mortality in severe COVID-19 cases. Pentoxifylline (PTX), a xanthine-derived drug registered for the treatment of vascular claudication, has been reported to display broad-spectrum anti-inflammatory and immunomodulatory properties via adenosine A2A receptor (A2AR)-related mechanisms, in parallel to its rheological actions. Prior studies have indicated the efficacy of PTX in the treatment of various pulmonary diseases, including the management of acute respiratory distress syndrome of infectious causes. Therefore, PTX has been proposed to have potential benefits in the treatment of SARS-CoV-2 symptoms, as well as its complications. The aim of this review is to discuss available knowledge regarding the role of PTX as a complementary therapeutic in SARS-CoV-2.

Can pentoxifylline and similar xanthine derivatives find a niche in COVID-19 therapeutic strategies? A ray of hope in the midst of the pandemic

COVID-19 pandemic presents an unprecedented challenge to identify effective drugs for treatment. Despite multiple clinical trials using different agents, there is still a lack of specific treatment for COVID-19. Having the potential role in suppressing inflammation, immune modulation, antiviral and improving respiratory symptoms, this review discusses the potential role of methylxanthine drugs like pentoxifylline and caffeine in the management of COVID-19 patients. COVID-19 pathogenesis for clinical features like severe pneumonia, acute lung injury (ALI) / acute respiratory distress syndrome (ARDS), and multi-organ failures are excessive inflammation, oxidation, and cytokine storm by the exaggerated immune response. Drugs like pentoxifylline have already shown improvement of the symptoms of ARDS and caffeine has been in clinical use for decades to treat apnea of prematurity (AOP) in preterm infants and improve respiratory function. Pentoxifylline is well-known anti-inflammatory and anti-oxidative molecules that have already shown to suppress Tumor Necrosis Factor (TNF-α) as well as other inflammatory cytokines in pulmonary diseases, and this may be beneficial for better clinical outcomes in COVID-19 patients. Pentoxifylline enhances blood flow, improves microcirculation and tissue oxygenation, and caffeine also efficiently improves tissue oxygenation, asthma, decreases pulmonary hypertension and an effective analgesic. There are significant shreds of evidence that proved the properties of pentoxifylline and caffeine against virus-related diseases as well. Along with the aforementioned evidences and high safety profiles, both pentoxifylline and caffeine offer a glimpse of considerations for future use as a potential adjuvant to COVID-19 treatment. However, additional clinical studies are required to confirm this speculation.

Harnessing adenosine A2A receptors as a strategy for suppressing the lung inflammation and thrombotic complications of COVID-19: Potential of pentoxifylline and dipyridamole

Counterproductive lung inflammation and dysregulated thrombosis contribute importantly to the lethality of advanced COVID-19. Adenosine A2A receptors (A2AR), expressed by a wide range of immune cells, as well as endothelial cells and platelets, exert cAMP-mediated anti-inflammatory and anti-thrombotic effects that potentially could be highly protective in this regard. The venerable drug pentoxifylline (PTX) exerts both anti-inflammatory and antithrombotic effects that reflect its ability to boost the responsiveness of A2AR to extracellular adenosine. The platelet-stabilizing drug dipyridamole (DIP) blocks intracellular uptake of extracellularly-generated adenosine, thereby up-regulating A2AR signaling in a way that should be functionally complementary to the impact of PTX in that regard. Moreover, DIP has recently been reported to slow the cellular replication of SARS-CoV-2 in clinically feasible concentrations. Both PTX and DIP are reasonably safe, well-tolerated, widely available, and inexpensive drugs. When COVID-19 patients can be treated within several days of symptom onset, using PTX + DIP in conjunction with hydroxychloroquine (HCQ) and an antibiotic – azithromycin (AZM) or doxycycline – might be warranted. HCQ and AZM can suppress SARS-CoV-2 proliferation in vitro and may slow the cell-to-cell spread of the virus; a large case series evaluating this combination in early-stage patients reported an impressively low mortality rate. However, whereas HCQ and AZM can promote QT interval lengthening and may be contraindicated in more advanced COVID-19 entailing cardiac damage, doxycycline has no such effect and exerts a potentially beneficial anti-inflammatory action. In contrast to HCQ, we propose that the combination of PTX + DIP can be used in both early and advanced stages of COVID-19. Concurrent use of certain nutraceuticals – yeast beta-glucan, zinc, vitamin D, spirulina, phase 2 inducers, N-acetylcysteine, glucosamine, quercetin, and magnesium – might also improve therapeutic outcomes in COVID-19.

The effect of Matrigel as scaffold material for neural stem cell transplantation for treating spinal cord injury

Traumatic injury to the spinal cord causes permanent loss of function and major personal, social, and economic problems. Cell-based delivery strategies is a promising approach for treating spinal cord injury (SCI). However, the inhospitable microenvironment in the injured spinal cord results in poor cell survival and uncontrolled differentiation of the transplanted stem cells. The combination of a scaffold with cells has been developed with a tendency for achieving greater survival and integration with the host tissue. We investigated the effect of Matrigel combined with neural stem cells (NSCs) in vitro and in vivo. We compared the effect of different types of scaffold on the survival and differentiation of brain-derived NSCs in an in vitro culture. Subsequently, NSCs were transplanted subcutaneously into nude mice to detect graft survival and differentiation in vivo. Finally, phosphate-buffered saline (PBS), Matrigel alone, or Matrigel seeded with NSCs was injected into 48 subacute, clinically relevant rat models of SCI (16 rats per group). Matrigel supported cell survival and differentiation efficiently in vitro and in vivo. SCI rats transplanted with NSCs in Matrigel showed improved behavioral recovery and neuronal and reactive astrocyte marker expression levels compared to PBS- or Matrigel-transplanted rats. Functional repair and neuronal and reactive astrocyte marker expression was slightly improved in the Matrigel-alone group relative to the PBS group, but not statistically significantly. These data suggest that Matrigel is a promising scaffold material for cell transplantation to the injured spinal cord.

Serum miR-146a and miR-150 as Potential New Biomarkers for Hip Fracture-Induced Acute Lung Injury

Background

Acute lung injury (ALI) and subsequent pulmonary infection are the most severe and usually fatal complications for elderly hip fracture patients. It is necessary to find some biomarkers for early diagnosis and prognosis of it.

Objective

This study is aimed at examining the differential expression of miR-146a, miR-150, and cytokines (IL-6 and IL-10) between younger and elderly rats suffering from hip fracture and investigating the possible meaning of them in early diagnosis and prognosis of ALI after hip fracture.

Methods and Subjects

Elderly rats and younger rats were randomly divided into sham group and fracture group, respectively. Two fracture groups received hip fracture operations. The damage degree of ALI was evaluated by histological observation and pathological score. Cytokines were measured by ELISA; miR-146a and miR-150 were analysed by qRT-PCR.

Results

After treatment, compared with the corresponding sham groups, the pulmonary histological score, the serum miR-146a concentrations, and the cytokine (IL-6 and IL-10) levels in serum and BALF were significantly higher (the miR-150 were lower) in the fracture groups (with the exception of IL-6 of the younger fracture group at 72 h, all P < 0.05). Meanwhile, compared with the younger fracture group, the aforementioned variables were significantly higher (the miR-150 levels were lower) in the elderly fracture group (with the exception of serum IL-10 and pulmonary histological score at 8 h, all P < 0.05). The results of linear regression analysis showed that serum miR-146a and miR-150 were significantly associated with pulmonary histological score.

Conclusion

Hip fracture can result in significant systemic inflammation and ALI in the rats. Compared to the younger rats, the elderly rats suffered a more remarkable ALI after hip fracture. It may be related to the abnormal expression of miR-146a and miR-150. Serum miR-146a and miR-150 are potential biomarkers for diagnosis and prognosis of ALI after hip fracture.

The kinetics of autophagy in the lung following acute spinal cord injury in rats

BACKGROUND CONTEXT

Lung injury is a major cause of respiratory complications following an acute spinal cord injury (ASCI), which are associated with a high mortality rate. Autophagy has been shown to be involved in a variety of lung diseases; however, whether autophagy is activated in the lung following ASCI remains unknown.

PURPOSE

The objective of this study was to investigate the induction of autophagy in the lung after ASCI.

STUDY DESIGN

This is an experimental animal study of ASCI investigating kinetics of autophagy in the lung following ASCI.

METHODS

One hundred and forty-four rats (N=144) were divided into two groups: (1) a sham (n=72) and (2) an injury group (n=72). Allen's method was used to induce an injury at the level of the 10th thoracic vertebra. Rats were sacrificed at 6, 12, 24, 48, and 72 hours, 1 week, and 2 weeks after surgery. Lung pathology and apoptosis were assessed to determine the level of damage in the lung. LC3, RAB7, P62, and Beclin 1 were used to detect the induction of autophagy. The study was funded by the Natural Science Foundation of China (NSFC,81272172); National Key Specialty Construction of Clinical Projects of China (#2013-544). The funder of the present study had no capacity to influence the scholarly conduct of the research, interpretation of results, or dissemination of study outcomes.

RESULTS

In the injury group, pathologic changes (i.e., pulmonary congestion, hemorrhage, inflammatory exudation, and alveolar collapse) occurred within the lung tissue within 72 hours after ASCI. Apoptosis of the lung cells gradually increased and peaked 72 hours after ASCI. Within 24 hours of ASCI, LC3 expression decreased, recovered, and gradually increased from 24 hours to 72 hours. As RAB7 decreased, P62 increased, and the ratio of RAB7/LC3 significantly decreased.

CONCLUSIONS

After ASCI, autophagy in the injured lung underwent dynamic changes, as early autophagosome formation decreased and late autophagosomes accumulated; thus, autophagy is in a state of inhibition.

Oral engineered Bifidobacterium longum expressing rhMnSOD to suppress experimental colitis

In recent years, using genetic engineering and bioengineering techniques, Bifidobacterium as a carrier to express specific functions of the protein or polypeptide, has become a new treatment for disease. Ulcerative colitis (UC) is a type of inflammatory bowel diseases (IBD). Although the cause of this inflammatory disorder is still unknown, a large amount of evidence suggests that ulcerative colitis is associated with increased activity of reactive oxygen species (ROS), manganese superoxide dismutase (MnSOD) is a kind of superoxide dismutase (SOD) has been demonstrated to play a key role in the pathophysiology of colitis. Here, we explored the Bifidobacterium as a drug delivery system to orally deliver a potent anti-inflammatory but poor penetration and stability antioxidant enzymes human MnSOD, transported into cells by a penetratin PEP-1. We constructed an expression vector expressing PEP-1-hMnSOD fusion protein, and successfully expressed hMnSOD fusion protein in engineered Bifidobacterium. Then we identified the bioactivity of engineered Bifidobacterium in LPS-induced inflammatory cell model. Finally, we used Bifidobacterium expressing PEP-1-hMnSOD fusion protein against DSS-induced ulcerative colitis mice. B. longum-PEP-1-rhMnSOD can successfully express rhMnSOD in the colon. We found that levels of inflammatory cytokines TNF-α, IL-1β, IL-6 and IL-8 as well as histological damage in colonic tissues showed that engineered Bifidobacterium effectively reduced dextran sulfate sodium(DSS)-induced ulcerative colitis, we also tested the MPO, verified the above conclusions. These results suggest that oral Bifidobacterium expressing PEP-1-hMnSOD fusion protein can be treated as a new method of UC treatment.

Spatiotemporal expression of Ski after rat spinal cord injury

Ski is an evolutionarily conserved protein and widely participates in the regulation of various pathological and physiological processes such as wound healing, liver regeneration, development of the embryonic nervous system, muscle differentiation, and progression of many kinds of tumors. However, the distribution and function of Ski in central nervous system lesion and disease remain unclear. In this study, we investigated the spatiotemporal expression of Ski in a spinal cord injury (SCI) model in adult rats. Western Blot analysis indicated that Ski was expressed in both normal and injured spinal cord, and showed a significant upregulation after SCI compared with the sham group. Double-labeled immunofluorescence staining showed that Ski was significantly expressed in astrocytes, but not in the neurons. Western Blot analyses of glial fibrillary acidic protein (GFAP) and BBB scores were carried out and correlation analysis showed a positive correlation between them. In addition, the relative expression level of Ski was also positively correlated with the relative expression level of GFAP. Moreover, the conspicuous co-expression band of Ski and GFAP at the lesion border was found in the results of immunofluorescence staining combined with the pattern of glial scar formation reflected by H&E staining; in addition, it was found that Ski was also highly associated with glial scar. On the basis of our data, we speculated that Ski might play an important role in the process of reactive astrogliosis after SCI and our study might provide a basis for further study on the detailed role of Ski in astrocytes.

Nrf2 plays a pivotal role in protection against burn trauma-induced intestinal injury and death

Nuclear factor (erythroid-derived 2)-like 2 (NRF2) is a basic leucine zipper transcription factor that principally defends against oxidative stress and also plays a unique role in severe sepsis. However, its contribution to intestinal injury and death after burn trauma is unclear.In this study, wild-type (Nrf2+/+) and Nrf2-deficient (Nrf2-/-) mice were subjected to 15% or 30% total body surface area burn or sham injury. Survival, systemic inflammation, and gut injury were determined.Nrf2-/- mice were more susceptible to burn-induced intestinal injury, as characterized by increases in damage to the gut structure and in intestinal permeability. This exacerbation was associated with an increase in the intestinal mRNA expression of inflammatory cytokines (interleukin [IL]-6, IL-1B, monocyte chemotactic protein 1, intercellular adhesion molecule, and vascular cell adhesion molecule) and a decrease in the intestinal mRNA expression of Nrf2-regulated genes (NAD(P)H dehydrogenasequinine-1 and glutamate-cysteine ligase modifier subunit). Nrf2-deficient mice also showed a lower survival rate and higher levels of systemic cytokines (IL-6 and IL-1B) and high-mobility group protein B1 than wild-type mice. This study demonstrates for the first time that mice that lack Nrf2 are more susceptible to burn-induced intestinal injury and have more systemic inflammation and a lower survival rate.

Combined Hemorrhagic Shock and Unilateral Common Carotid Occlusion Induces Neurological Injury in Adult Male Rats

Background: Clinical assessment reveals that patients after surgery of cardiopulmonary bypass or coronary bypass experience postoperative cognitive dysfunction. This study aimed to investigate whether resuscitation after a hemorrhagic shock (HS) and/or mild cerebral ischemia caused by a unilateral common carotid artery occlusion (UCCAO) can cause brain injury and concomitant neurological dysfunction, and explore the potential mechanisms. Methods: Blood withdrawal (6 mL/100 g body weight) for 60 min through the right jugular vein catheter-induced an HS. Immediately after the termination of HS, we reinfused the initially shed blood volumes to restore and maintain the mean arterial blood pressure (MABP) to the original value during the 30-min resuscitation. A cooling water blanket used to induce whole body cooling for 30 min after the end of resuscitation. Results: An UCCAO caused a slight cerebral ischemia (cerebral blood flow [CBF] 70%) without hypotension (MABP 85 mmHg), systemic inflammation, multiple organs injuries, or neurological injury. An HS caused a moderate cerebral ischemia (52% of the original CBF levels), a moderate hypotension (MABP downed to 22 mmHg), systemic inflammation, and peripheral organs injuries. However, combined an UCCAO and an HS caused a severe cerebral ischemia (18% of the original CBF levels), a moderate hypotension (MABP downed to 17 mmHg), systemic inflammation, peripheral organs damage, and neurological injury, which can be attenuated by whole body cooling. Conclusions: When combined with an HS, an UCCAO is associated with ischemic neuronal injury in the ipsilateral hemisphere of adult rat brain, which can be attenuated by therapeutic hypothermia. A resuscitation from an HS regards as a reperfusion insult which may induce neurological injury in patients with an UCCAO disease.

Modulating the Biologic Activity of Mesenteric Lymph after Traumatic Shock Decreases Systemic Inflammation and End Organ Injury

Introduction

Trauma/hemorrhagic shock (T/HS) causes the release of pro-inflammatory mediators into the mesenteric lymph (ML), triggering a systemic inflammatory response and acute lung injury (ALI). Direct and pharmacologic vagal nerve stimulation prevents gut barrier failure and alters the biologic activity of ML after injury. We hypothesize that treatment with a pharmacologic vagal agonist after T/HS would attenuate the biologic activity of ML and prevent ALI.

Methods

ML was collected from male Sprague-Dawley rats after T/HS, trauma-sham shock (T/SS) or T/HS with administration of the pharmacologic vagal agonist CPSI-121. ML samples from each experimental group were injected into naïve mice to assess biologic activity. Blood samples were analyzed for changes in STAT3 phosphorylation (pSTAT3). Lung injury was characterized by histology, permeability and immune cell recruitment.

Results

T/HS lymph injected in naïve mice caused a systemic inflammatory response characterized by hypotension and increased circulating monocyte pSTAT3 activity. Injection of T/HS lymph also resulted in ALI, confirmed by histology, lung permeability and increased recruitment of pulmonary macrophages and neutrophils to lung parenchyma. CPSI-121 attenuated T/HS lymph-induced systemic inflammatory response and ALI with stable hemodynamics and similar monocyte pSTAT3 levels, lung histology, lung permeability and lung immune cell recruitment compared to animals injected with lymph from T/SS.

Conclusion

Treatment with CPSI-121 after T/HS attenuated the biologic activity of the ML and decreased ALI. Given the superior clinical feasibility of utilizing a pharmacologic approach to vagal nerve stimulation, CPSI-121 is a potential treatment strategy to limit end organ dysfunction after injury.

Pulmonary edema and hemorrhage after acute spinal cord injury in rats

BACKGROUND CONTEXT

Respiratory complications are a major cause of morbidity and mortality during the first days after acute spinal cord injury (ASCI). However, the pathophysiology of respiratory insufficiency resulting from spinal cord injury that involves lower levels is less well understood.

PURPOSE

The aim of the present study was to investigate pulmonary pathophysiology after ASCI.

STUDY DESIGN

This is an experimental animal study of ASCI investigating pulmonary pathophysiology after ASCI.

METHODS

Eighty-four (N=84) rats were divided into two groups: a sham surgery (n=42) and an injury group (n=42). In the injury group, ASCI was induced at the level of the tenth thoracic vertebra by a modified Allen method. Rats were sacrificed 6 hours, 12 hours, 24 hours, 3 days, 1 week, 2 weeks, and 4 weeks after surgery. Pulmonary edema was assessed by calculating the ratio of the wet-to-dry lung weight (W:D). Pulmonary edema and hemorrhage were evaluated by observing gross and microscopic morphology. The study was funded by Natural Science Foundation of China (NSFC, 81272172). The funder of the present study had no capacity to influence the scholarly conduct of the research, interpretation of results, or dissemination of study outcomes.

RESULTS

In the injury group, W:D was significantly increased 12 hours after surgery compared with the sham surgery group; W:D peaked 3 days after ASCI (p<.05). Gross morphologic observations showed hemorrhagic lesions on the lung tissue 12 hours after ASCI and pulmonary edema 24 hours after ASCI. Pulmonary edema peaked 3 days after ASCI and was obviously decreased 1 week after ASCI. Hemorrhage was apparent until 2 weeks after ASCI. Light microscopy showed congestion of pulmonary capillaries 6 hours after ASCI. The pulmonary alveoli were filled with erythrocytes and serous extravasate 12 hours after ASCI. Hemorrhage and edema were observed in the interstitium and lung alveoli 24 hours after ASCI.

CONCLUSIONS

Early pathologic changes such as pulmonary congestion, hemorrhage, and edema after injury may be the basis for early respiratory dysfunction following ASCI.

Significance of Serum mtDNA Concentration in Lung Injury Induced by Hip Fracture

Acute lung injury is the most serious and fatal complication of the elderly patients with hip fracture, but the mechanisms are unknown. Recent studies demonstrated the mitochondrial DNA (mtDNA) release was associated with lung injury after trauma. This study aimed to examine the differential release of mtDNA between younger and elderly rats suffering from hip fracture and to investigate the possible mechanism of mtDNA in the lung injury induced by hip fracture. In the first part of the study, we investigated the effects of hip fracture on the rats. The elderly and younger rats, respectively, received hip fracture operations. The degree of lung injury was evaluated, toll-like receptor 9 (TLR9) and nuclear factor kappa B (NF-κB) were determined using Western blot, and mtDNA were analyzed by fluorescent quantitative polymerase chain reaction. In the second part of the study, we investigated the effects of mtDNA on the rats. The elderly and younger rats directly received intravenous injections with mtDNA. After 24 h, the specimens were collected and detected as the first part. Hip fracture resulted in significant mtDNA release, TLR9 and NF-κB p65 expression, and lung injury in the rats. Meanwhile, the mtDNA injection could indirectly induce lung injury. Compared to the younger ones, the elderly rats suffered more serious lung injury after hip fracture and mtDNA injection. These results suggest that the lung injury induced by hip fracture may be involved with the mtDNA release and its TLR9/NF-κB pathway.

Recombinant human brain natriuretic peptide attenuates trauma-/haemorrhagic shock-induced acute lung injury through inhibiting oxidative stress and the NF-κB-dependent inflammatory/MMP-9 pathway

Acute lung injury (ALI) is one of the most serious complications in traumatic patients and is an important part of multiple organ dysfunction syndrome (MODS). Recombinant human brain natriuretic peptide (rhBNP) is a peptide with a wide range of biological activity. In this study, we investigated local changes in oxidative stress and the NF-κB-dependent matrix metalloproteinase-9 (MMP-9) pathway in rats with trauma/haemorrhagic shock (TH/S)-induced ALI and evaluated the effects of pretreatment with rhBNP. Forty-eight rats were randomly divided into four groups: sham operation group, model group, low-dosage rhBNP group and high-dosage rhBNP group (n = 12 for each group). Oxidative stress and MPO activity were measured by ELISA kits. MMP-9 activity was detected by zymography analysis. NF-κB activity was determined using Western blot assay. With rhBNP pretreatment, TH/S-induced protein leakage, increased MPO activity, lipid peroxidation and metalloproteinase (MMP)-9 activity were inhibited. Activation of antioxidative enzymes was reversed. The phosphorylation of NF-κB and the degradation of its inhibitor IκB were suppressed. The results suggested that the protection mechanism of rhBNP is possibly mediated through upregulation of anti-oxidative enzymes and inhibition of NF-κB activation. More studies are needed to further evaluate whether rhBNP is a suitable candidate as an effective inhaling drug to reduce the incidence of TH/S-induced ALI.

The leukocyte-stiffening property of plasma in early acute respiratory distress syndrome (ARDS) revealed by a microfluidic single-cell study: the role of cytokines and protection with antibodies

Background

Leukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. 

Methods

This study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 cell line, were used. Cellular adhesiveness to human umbilical vein endothelial cells was examined using the laminar flow chamber method. We compared the properties of cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. 

Results

Rapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET <1 second) (p < 0.05). Systematic measurements with the THP-1 cell line allowed for the establishment of a strong correlation between stiffening and the severity of respiratory status (mean ET 0.82 ± 0.08 seconds for healthy subjects, 1.6 ± 1.0 seconds for ACPE groups, 10.5 ± 6.1 seconds for mild ARDS, and 20.0 ± 8.1 seconds for moderate to severe ARDS; p < 0.05). Stiffening correlated with the cytokines interleukin IL-1β, IL-8, tumor necrosis factor TNF-α, and IL-10 but not with interferon-γ, transforming growth factor-β, IL-6, or IL-17. Strong stiffening was induced by IL-1β, IL-8, and TNF-α but not by IL-10, and incubations with sera and blocking antibodies against IL-1β, IL-8, or TNF-α significantly diminished the stiffening effect of serum. In contrast, the measurements of integrin expression (CD11b, CD11a, CD18, CD49d) and leukocyte–endothelium adhesion showed a weak and slow response after incubation with the sera of patients with ARDS (several hours), suggesting a lesser role of leukocyte adhesiveness compared with leukocyte stiffness in early ARDS. 

Conclusions

The leukocyte stiffening induced by cytokines in the sera of patients might play a role in the sequestration of leukocytes in the lung capillary beds during early ARDS. The inhibition of leukocyte stiffening with blocking antibodies might inspire future therapeutic strategies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1157-5) contains supplementary material, which is available to authorized users.

Diphenyldifluoroketone EF24 Suppresses Pro-inflammatory Interleukin-1 receptor 1 and Toll-like Receptor 4 in lipopolysaccharide-stimulated dendritic cells

Background

Unresolved and prolonged inflammation is a pathological basis of many disorders such as cancer and multiple organ failure in shock. Interleukin-1 receptor (IL-1R) superfamily consists of IL-1R1 and pathogen pattern recognition receptor toll-like receptor-4 (TLR4) which, upon ligand binding, initiate pro-inflammatory signaling. The study objective was to investigate the effect of a diphenyldifluoroketone EF24 on the expression of IL-1R1 and TLR4 in lipopolysaccharide (LPS)-stimulated dendritic cells (DCs).

Methods

Immortalized murine bone marrow-derived JAWS II dendritic cells (DC) were challenged with LPS (100 ng/ml) for 4 h. The LPS-stimulated DCs were treated with 10 μM of EF24 for 1 h. The expression levels of IL-1R1 and TLR4 were monitored by RT-PCR, immunoblotting, and confocal microscopy. The effect of EF24 on the viability and cell cycle of DCs was examined by lactate dehydrogenase assay and flow cytometry, respectively.

Results

EF24 treatment suppressed the LPS-induced TLR4 and IL-1R1 expression in DCs. However, the expression levels of IL-1RA and IL-1R2 were not influenced by either LPS or EF24 treatments. These effects of EF24 were associated with a decrease in LPS-induced expression of phospho-NF-kB p65, indicative of its role in the transcriptional control of IL-1R superfamily members. We did not find any significant effect of EF24 on the proliferation or cell cycle of DCs.

Conclusions

The results suggest that EF24 influences IL-1R superfamily signaling pathway in ways that could have salutary effects in inflammation. The pluripotent anti-inflammatory actions of EF24 warrant further investigation of EF24 in inflammatory conditions of systemic nature.

The Immediate Intramedullary Nailing Surgery Increased the Mitochondrial DNA Release That Aggravated Systemic Inflammatory Response and Lung Injury Induced by Elderly Hip Fracture

Conventional concept suggests that immediate surgery is the optimal choice for elderly hip fracture patients; however, few studies focus on the adverse effect of immediate surgery. This study aims to examine the adverse effect of immediate surgery, as well as to explore the meaning of mtDNA release after trauma. In the experiment, elderly rats, respectively, received hip fracture operations or hip fracture plus intramedullary nail surgery. After fracture operations, the serum mtDNA levels as well as the related indicators of systemic inflammatory response and lung injury significantly increased in the rats. After immediate surgery, the above variables were further increased. The serum mtDNA levels were significantly related with the serum cytokine (TNF-α and IL-10) levels and pulmonary histological score. In order to identify the meaning of mtDNA release following hip fracture, the elderly rats received injections with mtDNA. After treatment, the related indicators of systemic inflammatory response and lung injury significantly increased in the rats. These results demonstrated that the immediate surgery increased the mtDNA release that could aggravate systemic inflammatory response and lung injury induced by elderly hip fracture; serum mtDNA might serve as a potential biomarker of systemic inflammatory response and lung injury following elderly hip fracture.

Evaluation of verapamil efficacy in Peyronie's disease comparing with pentoxifylline

INTRODUCTION

Peyronie's disease described as penile curvature, fibromathosis and pain that occur most often in men aged 40 to 60 years. The main complaint that caused the patient to visit the clinic is nodules on the upper surface of the penis, causing curvature and distortion particularly during erection, but they don't have any urinary problem. In this study, we evaluated the effect of verapamil compared to pentoxifylline in Peyronie's disease.

METHODS

In this study, 90 patients with signs and symptoms of Peyronie's disease which were diagnosed and were in the age range 40 to 70 years enrolled. The patients were randomly divided into 3 groups. First group received pentoxifylline orally at a dose of 400 mg three times a day, in the second group verapamil (10 mg every other week for up to 12 sessions) was injected into the lesion and the third group received both treatments in combination.

RESULTS

In patients, who received pentoxifylline, curvature reduction was 26.7%, plaque size reduction was 30%, the recovery rate of erectile dysfunction was 46.7% and pain reduced was 73.3%. Each of these cases in patients, who used beta-blockers, was 36.7%, 33.3%, 66.7% and 76.6%. In combination therapy, curvature reduction was 36.7%, plaque size reduction was 33.3%, the recovery rate of erectile dysfunction was 86.7% and pain reduced was 80%.

CONCLUSION

In our study there was no significant difference between two groups using verapamil or pentoxifylline, but there was a significant improvement in combination therapy group. Due to our results we propose that combination therapy can improve results and should be considered as a choice in treatment of Peyronie's disease. 

Pentoxifylline attenuates leukocyte-endothelial interactions in a two-hit model of shock and sepsis

BACKGROUND

This study investigated the effects of pentoxifylline (PTX) combined with resuscitation fluids on microcirculatory dysfunctions in a two-hit model of shock and sepsis.

MATERIALS AND METHODS

Male Wistar rats (250 g) were submitted to hemorrhagic shock and reperfusion followed by sepsis induced by cecal ligation and puncture. For the initial treatment of shock, rats were randomly divided into: sham, no injury, no treatment; hypertonic saline solution (HS) (7.5%, 4 mL/kg); lactated Ringer's solution (LR, 3 × shed blood volume); HS + PTX (4 mL/Kg + 25 mg/kg PTX); and LR + PTX (3 × shed blood volume + 25 mg/kg PTX). After 48 h of being exposed to the double injury, leukocyte-endothelial interactions were assessed by intravital microscopy of the mesentery. Endothelial expression of P-selectin and intercellular adhesion molecule-1 (ICAM-1) was evaluated by immunohistochemistry, as well as lung neutrophil infiltration by histology.

RESULTS

Lactated Ringer's solution induced marked increases (P < 0.001) in the number of rolling leukocytes per 10 min (two-fold), adherent leukocytes per 100 μm venule length (six-fold), migrated leukocytes per 5000 μm(2) (eight-fold), P-selectin and ICAM-1 expression (four-fold), and lung neutrophil infiltration (three-fold) compared with sham. In contrast, PTX attenuated leukocyte-endothelial interactions, P-selectin and ICAM-1 expression at the mesentery when associated with either LR (P < 0.001) or HS (P < 0.05). Neutrophil migration into the lungs was similarly reduced by PTX (P < 0.05).

CONCLUSIONS

Data presented showed that pentoxifylline attenuates microcirculatory disturbances at the mesenteric bed with significant minimization of lung inflammation after a double-injury model of hemorrhagic shock and reperfusion followed by sepsis.

The vagus nerve alters the pulmonary dendritic cell response to injury

BACKGROUND

We have shown previously that vagal nerve stimulation (VNS) protects against burn-induced acute lung injury (ALI). Although the mobilization and activation of immune cells is central to tissue injury caused by the systemic inflammatory response, the specific inflammatory cell populations that are modulated by VNS have yet to be fully defined. The purpose of this study was to assess whether VNS alters inflammatory cell recruitment to the lung after severe burn injury.

MATERIALS AND METHODS

Male C57BL/6 mice were subjected to 30% total body surface area steam burn with and without electrical stimulation of the right cervical vagus nerve. The relative levels of pulmonary dendritic cells (DC) and macrophages were compared at 4 h versus 24 h after burn injury. Lung tissue injury was characterized by histology to assess changes in lung architecture, and measure the protein levels of interleukin 6 and transforming growth factor-β1.

RESULTS

Severe burn caused an increase in pulmonary DC recruitment at 4 h after injury that persisted at 24 h after severe burn, whereas there was no change in the number of pulmonary macrophages. In contrast, VNS limited the burn-induced recruitment of pulmonary DC. VNS prevented histologic lung injury and attenuated the release of interleukin 6 and transforming growth factor-β1 in the lung after burn injury.

CONCLUSIONS

VNS is an effective method to limit pulmonary DC recruitment to the lung and prevent ALI after burn injury. Identifying strategies to limit inflammatory cell recruitment to the lung may have clinical utility in preventing ALI in severely burned patients.

Hip fracture aggravates systemic inflammation and lung injury in aged chronic cigarette smoke exposed rats

The aim of this investigation was to examine the influence of hip fracture on systemic inflammation and lung injury in aged chronic cigarette smoke exposed rats. Male Sprague Dawley (SD) aged rats (22-25 months old, 460-570 g) were used. Animals were subjected to either chronic cigarette smoke (CS) or air exposure for 12 weeks. These animals then underwent a sham procedure or hip fracture. Endpoint was 24 h. Systemic inflammation was assessed by TNF-α, IL-6, and IL-10 levels. Pulmonary function, inflammatory cell counts and protein concentrations in BAL, pulmonary pathological changes and scores were obtained to assess lung injury. And TLR4 mRNA expression in lung tissue was determined. The indices mentioned above were unchanged in air-exposed rats after hip fracture. However, CS-exposed animals were found to have increased serum levels of TNF-α, IL-6, and IL-10, impaired pulmonary function, increased inflammatory cell counts and protein concentrations in BAL, and intensified pathologic changes and scores. In addition, lung tissue harvested following CS-exposure demonstrated increased TLR4 mRNA expression. Our results indicate that systemic inflammation and lung injury in aged CS-exposed animals were further aggravated by hip fracture. The overexpression of TLR4 mRNA induced by CS exposure may, at least in part, involve in this process.

Systemic inflammatory responses and lung injury following hip fracture surgery increases susceptibility to infection in aged rats

Pulmonary infections frequently occur following hip fracture surgery in aged patients. However, the underlying reasons are not fully understood. The present study investigates the systemic inflammatory response and pulmonary conditions following hip fracture surgery as a means of identifying risk factors for lung infections using an aged rodent model. Aged, male Sprague-Dawley rats (8 animals per group) underwent a sham procedure or hip fracture plus femoral intramedullary pinning. Animals were sacrificed 1, 3, and 7 days after the injury. Markers of systemic inflammation and pulmonary injury were analyzed. Both sham-operated and injured/surgical group animals underwent intratracheal inoculation with Pseudomonas aeruginosa 1, 3, and 7 days after surgery. P. aeruginosa counts in blood and bronchoalveolar lavage (BAL) fluid and survival rates were recorded. Serum TNF-α, IL-6, IL-1β, and IL-10 levels and markers of pulmonary injury were significantly increased at 1 and 3 days following hip fracture and surgery. Animals challenged with P. aeruginosa at 1 and 3 days after injury had a significantly decreased survival rate and more P. aeruginosa recovered from blood and BAL fluid. This study shows that hip fracture and surgery in aged rats induced a systemic inflammatory response and lung injury associated with increased susceptibility to infection during the acute phase after injury and surgery.

Pharmacologic suppression of inflammation by a diphenyldifluoroketone, EF24, in a rat model of fixed-volume hemorrhage improves survival

An exaggerated release of proinflammatory cytokines and accompanying inflammation contributes to the development of multiple organ failure after hemorrhagic shock. Here, we tested the nuclear factor (NF) κ-light-chain-enhancer of activated B cell (NF-κB)-mediated transcriptional control of inflammatory pathways as a target in the management of hemorrhage-induced inflammation. We performed a study in a rat model of fixed-volume hemorrhage to investigate the anti-inflammatory effects of the diphenyldifluoroketone EF24 [3,5-bis(2-fluorobenzylidene)piperidin-4-one], an NF-κB inhibitor, in lung tissue. EF24 treatment (0.4 mg/kg) significantly prevented the upregulation of inflammatory biomarkers in rats subjected to 50% hemorrhage and preserved the pulmonary histology in hemorrhaged rats. The lung tissue from treated rats showed marked suppression of the hemorrhage-mediated induction of Toll-like receptor 4, phospho-p65 NF-κB, inducible nitric-oxide synthase, heme oxygenase-1, and cyclooxygenase-2 (COX-2). The hemorrhage-induced COX-2 activity was also significantly inhibited by the EF24 treatment. At the same time, EF24 induced nuclear factor (erythroid-derived 2)-like 2-mediated protective mechanisms against oxidative stress. EF24 also reduced hemorrhage-induced lung myeloperoxidase activity. The plasma levels of proinflammatory tumor necrosis factor-α, interleukin (IL)-6, IL-1α, and IL-1β were lower in EF24-treated rats than in untreated rats. Moreover, there was a significant reduction in the pulmonary expression of high-mobility group B1 protein. These biochemical effects were accompanied by a significant improvement in the survival of rats administered with EF24 as compared with the rats receiving vehicle control (P < 0.05). Overall, the results suggest that EF24 attenuates hemorrhage-induced inflammation and could serve as a salutary anti-inflammatory agent in resuscitation strategies.

Uncovering the neuroenteric-pulmonary axis: vagal nerve stimulation prevents acute lung injury following hemorrhagic shock

AIMS

Trauma/hemorrhagic shock (T/HS) induced gut injury is known to initiate a systemic inflammatory response which can lead to secondary lung injury. We have shown that vagal nerve stimulation (VNS) protects intestinal epithelial integrity after a severe burn insult. We hypothesize that VNS will protect the lung from injury following T/HS by preventing intestinal barrier failure.

MAIN METHODS

Male Balb/c mice were subjected to a T/HS model with and without cervical VNS. Intestinal injury was evaluated by measuring changes in gut barrier function and tight junction protein localization. Lung injury was evaluated using histology and markers of lung inflammation. Using NF-kB-luciferase (NF-kB-luc) transgenic mice, NF-kb-DNA binding was measured by photon emission analysis at 4 after injury.

KEY FINDINGS

T/HS is associated gut injury characterized by histologic injury, increased epithelial permeability, and altered localization of gut tight junction proteins. Cervical VNS prevented the T/HS-induced changes in gut barrier integrity. Gut injury after T/HS was associated with acute lung injury at 24 h characterized by histologic injury, increased number of MPO positive stained cells and MPO enzymatic activity, and increased ICAM-1 expression in lung endothelium. VNS decreased T/HS-induced lung injury with a marked decrease in lung inflammation compared to T/HS alone. Lungs harvested from NF-kB-luc mice at 4h post VNS+T/HS demonstrated decreased DNA binding of NF-kB compared to T/HS alone as measured by changes in bioluminescence.

SIGNIFICANCE

VNS is effective in protecting against acute lung injury caused by hemorrhagic shock through its ability to prevent gut barrier dysfunction.

Pulmonary impact of N-acetylcysteine in a controlled hemorrhagic shock model in rats

BACKGROUND

Experimental hemorrhagic shock (HS) is based on controlling bleeding and the treatment of fluid resuscitation to restore tissue oxygenation and perfusion. The HS could promote ischemia/reperfusion injury, which induces a general exacerbation of the inflammatory process, initially compromising the lungs. N-acetylcysteine (NAC), an antioxidant, may attenuate ischemia/reperfusion injury. This study evaluated the effect of NAC in association with fluid resuscitation on pulmonary injury in a controlled HS model in rats.

METHODS

Male Wistar rats were submitted to controlled HS (mean arterial pressure of 35 mm Hg for 60 min). Two groups were constituted according to resuscitation solution administered: RLG (Ringer's lactate solution) and RLG+NAC (Ringer's lactate in association with 150 mg/kg NAC. A control group was submitted to catheterization only. After 120 min of resuscitation, bronchoalveolar lavage was performed to assess intra-alveolar cell infiltration and pulmonary tissue was collected for assessment of malondialdehyde, interleukin 6, and interleukin 10 and histopathology.

RESULTS

Compared with the RLG group, the RLG+NAC group showed lower bronchoalveolar lavage inflammatory cell numbers, lower interstitial inflammatory infiltration in pulmonary parenchyma, and lower malondialdehyde concentration. However, tissue cytokine (interleukin 6 and interleukin 10) expression levels were similar.

CONCLUSION

N-acetylcysteine was associated with fluid resuscitation-attenuated oxidative stress and inflammatory cell infiltration in pulmonary parenchyma. N-acetylcysteine did not modify cytokine expression.

Burn-induced acute lung injury requires a functional Toll-like receptor 4

The role of the Toll-like receptor 4 (TLR4), a component of the innate immune system, in the development of burn-induced acute lung injury (ALI) has not been completely defined. Recent data suggested that an intact TLR4 plays a major role in the development of organ injury in sterile inflammation. We hypothesized that burn-induced ALI is a TLR4-dependent process. Male C57BL/6J (TLR4 wild-type [WT]) and C57BL/10ScN (TLR4 knockout [KO]) mice were subjected to a 30% total body surface area steam burn. Animals were killed at 6 and 24 h after the insult. Lung specimens were harvested for histological examination after hematoxylin-eosin staining. In addition, lung myeloperoxidase (MPO) and intercellular adhesion molecule 1 immunostaining was performed. Lung MPO was measured by an enzymatic assay. Total lung keratinocyte-derived chemoattractant (IL-8) content was measured by enzyme-linked immunosorbent assay. Western blot was performed to quantify phosphorylated IκBα, phosphorylated nuclear factor κB p65 (NF-κBp65), and high mobility group box 1 expression. Acute lung injury, characterized by thickening of the alveolar-capillary membrane, hyaline membrane formation, intraalveolar hemorrhage, and neutrophil infiltration, was seen in WT but not KO animals at 24 h. Myeloperoxidase and intercellular adhesion molecule 1 immunostaining of KO animals was also similar to sham but elevated in WT animals. In addition, a reduction in MPO enzymatic activity was observed in KO mice as well as a reduction in IL-8 levels compared with their WT counterparts. Burn-induced ALI develops within 24 h after the initial thermal insult in our model. Toll-like receptor 4 KO animals were clearly protected and had a much less severe lung injury. Our data suggest that burn-induced ALI is a TLR4-dependent process.

Efferent vagal nerve stimulation attenuates acute lung injury following burn: The importance of the gut-lung axis

BACKGROUND

The purpose of this study was to assess acute lung injury when protection to the gut mucosal barrier offered by vagus nerve stimulation is eliminated by an abdominal vagotomy.

METHODS

Male balb/c mice were subjected to 30% total body surface area steam burn with and without electrical stimulation to the right cervical vagus nerve. A cohort of animals were subjected to abdominal vagotomy. Lung histology, myeloperoxidase and ICAM-1 immune staining, myeloperoxidase enzymatic assay, and tissue KC levels were analyzed 24 hours after burn. Additionally, lung IkB-α, NF-kB immunoblots, and NF-kB-DNA binding measured by photon emission analysis using NF-kB-luc transgenic mice were performed.

RESULTS

Six hours post burn, phosphorylation of both NF-kB p65 and IkB-α were observed. Increased photon emission signal was seen in the lungs of NF-kB-luc transgenic animals. Vagal nerve stimulation blunted NF-kB activation similar to sham animals whereas abdominal vagotomy eliminated the anti-inflammatory effect. After burn, MPO positive cells and ICAM-1 expression in the lung endothelium was increased, and lung histology demonstrated significant injury at 24 hours. Vagal nerve stimulation markedly decreased neutrophil infiltration as demonstrated by MPO immune staining and enzyme activity. Vagal stimulation also markedly attenuated acute lung injury at 24 hours. The protective effects of vagal nerve stimulation were reversed by performing an abdominal vagotomy.

CONCLUSION

Vagal nerve stimulation is an effective strategy to protect against acute lung injury following burn. Moreover, the protective effects of vagal nerve stimulation in the prevention of acute lung injury are eliminated by performing an abdominal vagotomy. These results establish the importance of the gut-lung axis after burn in the genesis of acute lung injury.

Magnolol attenuates the lung injury in hypertonic saline treatment from mesenteric ischemia reperfusion through diminishing iNOS

BACKGROUND

Hypertonic saline (HTS) administration can decrease the inflammation following ischemia reperfusion. Magnolol is a potent antioxidant. The present study investigated whether combined treatment of magnolol and HTS could provide further protection in mesenteric ischemia reperfusion injury.

METHODS

Male C3H/HeOuJ mice were randomly segregated into the following groups: sham-operated (sham), vehicle treatment and mesenteric ischemia reperfusion (MSIR) (vehicle-treated), magnolol treatment and MSIR (magnolol-treated), HTS treatment and MSIR (HTS-treated), as well as co-administration of magnolol plus HTS and MSIR (combined-treated). In MSIR, mice were subjected to mesenteric ischemia for 60 min followed by reperfusion for 30 min. Lung injury was evaluated by lung edema (water ratio) and myeloperoxide (MPO) activity; RNA expression of inducible nitric oxide synthetase (iNOS), TNF-α, and IL-6 were assayed by real time RT-PCR. The formation of peroxynitrite in plasma was assayed by the peroxynitrite-dependent oxidation of dihydrorhodamine 123 (DHR 123) to rhodamine.

RESULTS

Compared with those in the sham-treated group, lung edema and MPO activity, expressions of iNOS, TNF-α and IL-6, and plasma peroxynitrite were significantly increased in the vehicle-treated group. Significant attenuations of these parameters were found in the magnolol-treated or HTS-treated animals. Combined treatment of magnolol and HTS further suppressed the lung edema, iNOS, and TNF-α expressions, and plasma peroxynitrite, compared with the results of a single treatment of magnolol or HTS.

CONCLUSIONS

Compared with single-agent use, co-administration of magnolol and HTS further decreases iNOS expression and plasma peroxynitrite as well as the degree of lung injury from MISR. These results may provide another treatment measure for post-injury immunomodulation.

Anti-inflammatory effects and possible mechanism of action of lupeol acetate isolated from Himatanthus drasticus (Mart.) Plumel

BACKGROUND

The species Himatanthus drasticus is popularly known in Northeast Brazil as "janaguba" and belongs to the family Apocynaceae. The latex collected from its stem bark is used for several purposes including anti-inflammatory properties and presents among its bioactive constituents the pentacyclic triterpene lupeol. The objective of the present work was to study in vivo and in vitro the lupeol acetate (LA) isolated from the plant latex, in several models of inflammation.

METHODS

Male Swiss mice (25-30 g, 6-24 animals per group) were administered with LA, 30 min before the test initiation. In the evaluation of analgesic activity the formalin test was used. The anti-inflammatory activity was evaluated by the following tests: paw edema induced by carrageenan and dextran, and the carrageenan-induced neutrophil migration into peritoneal cavities. Furthermore, the effect of LA on the myeloperoxidase release (MPO, an inflammation biomarker) from human neutrophils was also determined, as well as its antioxidant potential by the DPPH assay.

RESULTS

In the formalin test, LA (10, 25 and 50 mg/kg, i.p.) inhibited both the 1st (neurogenic, 0-5 min) and mainly the 2nd (inflammatory, 20-25 min) phase. Naloxone completely reversed the LA effect, indicating the participation of the opioid system. LA also significantly inhibited carrageenan- and dextran-induced paw edemas, as well as the neutrophil migration to the peritoneal cavity evaluated by the carrageenan-induced pleurisia. In this model, the effect of a very low dose of LA (0.1 mg/kg) was potentiated by the same dose of pentoxifylline (PTX), a known TNF-alpha inhibitor. LA (25 and 50 μg/ml) was also very effective in inhibiting MPO released from stimulated human neutrophils, and significantly decreased the number of cells expressing iNOS activity in the paw of mice submitted to carrageenan-induced edema, suggesting a drug involvement with the NO system.

CONCLUSIONS

The anti-inflammatory effect of LA probably involves the opioid system, as indicated by the complete blockade of the opioid antagonist naloxone. Furthermore, the LA effect was potentiated by PTX (a TNF-alpha inhibitor). LA also decreased the number of iNOS cells, suggesting the participation of pro-inflammatory cytokines and the NO system in the drug action.

Advances in resuscitation strategies

Shock, regardless of etiology is characterized by decreased delivery of oxygen and nutrients to the tissues and our interventions are directed towards reversing the cellular ischemia and preventing its consequences. The treatment strategies that are most effective in achieving this goal obviously depend upon the different types of shock (hemorrhagic, septic, neurogenic and cardiogenic). This brief review focuses on the two leading etiologies of shock in the surgical patients: bleeding and sepsis, and addresses a number of new developments that have profoundly altered the treatment paradigms. The emphasis here is on new research that has dramatically altered our treatment strategies rather than the basic pathophysiology of shock.

Effects of pentoxifylline on inflammation and lung dysfunction in ventilated septic animals

Acute respiratory distress syndrome secondary to sepsis is associated with high morbidity and mortality. The purpose of this study was to characterize the effects of ventilatory strategy and the modulating activity of pentoxifylline in a sepsis-induced lung dysfunction model. Male Wistar rats were randomly divided into six groups, undergoing two different ventilatory strategies. Rats received live Escherichia coli or saline intraperitoneally. After 6 hours, the septic animals were treated with either pentoxifylline (25 mg/kg for 20 minutes) or normal saline infusion and ventilated with low tidal volume (6 mL/kg; septic animals with E. coli intraperitoneal [IP] infusion, PTX-treated and ventilated with low tidal volume and septic animals with E. coli IP infusion and ventilated with low tidal volume, respectively) or high tidal volume (12 mL/kg; septic animals with E. coli IP infusion, PTX-treated and ventilated with high tidal volume and septic animals with E. coli IP infusion and ventilated with high tidal volume, respectively) for 3 hours. The control animals received normal saline infusion and, after 6 hours, were ventilated with low or high tidal volume (control animals with saline infusion and ventilated with low tidal volume and control animals with saline infusion and ventilated with high tidal volume, respectively). Lung dysfunctions were assessed by wet-to-dry lung ratios, total cell count, total protein, malondialdehyde, and tumor necrosis factor-alpha concentrations in bronchoalveolar lavage (BAL). Septic animals with E. coli IP infusion and ventilated with high tidal volume presented increased wet-to-dry lung ratios, total cell count, total protein, and malondialdehyde in BAL compared with the septic animals ventilated with low tidal volume. Septic animals treated with pentoxifylline presented higher arterial oxygenation and lower cellular influx, protein leakage, malondialdehyde concentration, and tumor necrosis factor-alpha levels in BAL compared with septic animals undergoing the same ventilatory support strategies (septic animals with E. coli IP infusion and ventilated with low tidal volume and septic animals with E. coli IP infusion and ventilated with high tidal volume). Ventilatory strategy modulated the inflammatory response and pulmonary alterations in a sepsis-induced acute lung injury model, and these effects are improved by pentoxifylline.

Pentoxifylline attenuates transforming growth factor-beta1-stimulated elastogenesis in human tunica albuginea-derived fibroblasts part 2: Interference in a TGF-beta1/Smad-dependent mechanism and downregulation of AAT1

INTRODUCTION

Transforming growth factor-beta1 (TGF-beta1) contributes to the pathogenesis of Peyronie's disease (PD). Pentoxifylline (PTX) antagonizes the effects of TGF-beta1 and has been utilized in our clinic for the management of PD although the mechanisms of action are not entirely clear.

AIM

We studied cell-signaling pathways through which TGF-beta1 and PTX mediate collagen metabolism, elastin expression, and elastogenesis in tunica albuginea-derived fibroblasts (TADFs).

METHODS

TADFs from men with and without PD were cultured and treated with TGF-beta1 and PTX as monotherapy at differing concentrations and time points. Combination treatment (TGF-beta1 followed by PTX and vice versa) was also investigated.

MAIN OUTCOME MEASURES

Reverse-transcription polymerase chain reaction and Western blotting were utilized to assess differences in elastin metabolism and cellular signaling between groups. Alpha-1 antitrypin (AAT1) expression was assayed.

RESULTS

At doses greater than 0.1 ng/Ml, TGF-beta1 increased messenger ribonucleic acid (mRNA) and protein expression of elastin in a time-dependent fashion in TADF. PTX did not interfere with TGF-beta1 mediated upregulation of elastin mRNA and protein in TADF. However, pretreatment of TADF with PTX was associated with decreased expression of AAT1, decreased activity of the Smad1/5 pathway, and enhanced phosphorylation of the inhibitory Smad6.

CONCLUSION

Expression of elastin mRNA and protein is upregulated in TADF by TGF-beta1. PTX has no effect on elastin production but attenuates elastogenesis in TADF through an AAT1-related mechanism.

Induced hypothermia attenuates the acute lung injury in hemorrhagic shock

BACKGROUND

In previous animal studies, induction of therapeutic hypothermia (HT) in hemorrhagic shock (HS) had beneficial effects on the hemodynamic and metabolic parameters and on the survival. However, the effect of induced HT on acute lung injury (ALI) in HS has not been investigated. We sought to determine the effects of HT on ALI in HS.

METHODS

Male Sprague-Dawley rats (350-390 g; n = 8 per group) were randomized to the normothermia (NT; 36-37 degrees C) group or the moderate HT (27-30 degrees C) group and were subjected to volume-controlled (2 mL/100 g weight) HS (90 minutes) followed by 90 minutes of resuscitation. ALI score, lung malondialdehyde content, and myeloperoxidase activity were measured. The expression of glycogen synthase kinase 3beta (GSK-3beta), phosphorylated GSK-3beta, inducible nitric oxide synthase (iNOS), heat shock protein (HSP) 72, and nuclear factor-kappaB (NF-kappaB) in the lung were compared.

RESULTS

ALI score, lung malondialdehyde content, and myeloperoxidase were lower in the HT group. GSK-3beta and iNOS gene expressions in lung tissue were significantly decreased in the HT group (p < 0.05). On the contrary, the expression of phosphorylated GSK-3beta was increased in the HT group (p < 0.001). HSP 72 was expressed in the HT group but not in the NT group. The activated p65 NF-kappaB levels in lung nuclear extract were significantly lower in the NT group (p = 0.03).

CONCLUSIONS

HT attenuates HS-induced ALI in rats by the modulation of GSK, HSP 72, iNOS, and NF-kappaB.

Pentoxifylline attenuates transforming growth factor-β1-stimulated collagen deposition and elastogenesis in human tunica albuginea-derived fibroblasts part 1: impact on extracellular matrix

INTRODUCTION

Transforming growth factor-β1 (TGF-β1) has been implicated in the pathogenesis of Peyronie's disease (PD) and also plays a role in collagen and elastin metabolism. Pentoxifylline (PTX) antagonizes the effects of TGF-β1 and has been utilized in our clinic for the management of PD.

AIM

We studied the effects of TGF-β1 and PTX on collagen metabolism and elastogenesis in tunica albuginea-derived fibroblasts (TADFs).

METHODS

TADFs from men with and without PD were cultured and treated with TGF-β1 and PTX as monotherapy at differing concentrations and time points. Combination treatment (TGF-β1 followed by PTX and vice versa) was also investigated.

MAIN OUTCOME MEASURES

Cell proliferation assay, enzyme-linked immunosorbent assay, and immunohistochemistry were utilized to assess the impact of TGF-β1 and PTX on TADF with respect to elastin and collagen I metabolism.

RESULTS

PTX inhibited fibroblast proliferation at doses of 100 µM. TGF-β1 stimulated elastogenesis and collagen I fiber deposition in TADF in a dose- and time-dependent fashion. Pretreatment with PTX dramatically attenuated TGF-β1-mediated elastogenesis and collagen fiber deposition in TADF from men with and without PD. Interestingly, production of collagen I was higher in untreated Peyronie's tunica (PT) cells relative to normal tunica (NT) cells; furthermore, PTX attenuated collagen production to levels similar to untreated control TADF in PT cells but not in NT cells, suggesting important intrinsic differences between PT and NT cells.

CONCLUSION

Both elastin and collagen are upregulated by TGF-β1 in TADF. This likely contributes to the PD phenotype. Pretreatment with PTX attenuates both collagen fiber deposition and elastogenesis in TADF exposed to TGF-β1; these effects suggest a useful role for PTX in the management of PD.

DSM-RX78, a new phosphodiesterase inhibitor, suppresses superoxide anion production in activated human neutrophils and attenuates hemorrhagic shock-induced lung injury in rats

Neutrophils are activated following hemorrhagic shock and the accumulation of neutrophils in the lung is associated with lung injury. This research investigated the effects of a semisynthetic 2-benzoylaminobenzoic acid derivative, methyl 2-(2-fluorobenzamido)benzoate (DSM-RX78), on superoxide anion (O(2)(-)) production in formyl-l-methionyl-l-leucyl-l-phenylalanine (FMLP)-activated human neutrophils, and on lung injury in Sprague-Dawley rats subjected to trauma-hemorrhage. DSM-RX78 concentration-dependently inhibited O(2)(-) production, but not elastase release, in FMLP-activated human neutrophils. DSM-RX78 displayed no superoxide-scavenging ability, and it failed to alter the subcellular NADPH oxidase activity. Significantly, DSM-RX78 increased cAMP formation and protein kinase (PK)A activity in FMLP-activated neutrophils, which occurred through the selective inhibition of cAMP-specific phosphodiesterase (PDE) activity but not an increase in adenylate cyclase function or cGMP-specific PDE activity. These results show that DSM-RX78 is a new inhibitor of cAMP-specific PDE. Moreover, DSM-RX78 reduced FMLP-induced phosphorylation of protein kinase B (Akt), but not calcium mobilization. The inhibitory effects of DSM-RX78 on O(2)(-) production and Akt phosphorylation were reversed by PKA inhibitors, suggesting that DSM-RX78 regulates O(2)(-) production of human neutrophils by promoting cAMP/PKA-dependent inhibition of Akt activation. On the other hand, administration of DSM-RX78 significantly attenuated the increase in myeloperoxidase activity and edema in the lung, as well as protein concentrations in bronchoalveolar lavage fluid in rats after trauma-hemorrhagic shock. In summary, these results strongly suggest that DSM-RX78 exerts anti-inflammatory effects, which result from the elevation of cAMP levels and PKA activity through its inhibition of cAMP-specific PDE. Also, our findings show that DSM-RX78 attenuates hemorrhagic shock-induced lung injury in rats.

Ketamine delays mortality in an experimental model of hemorrhagic shock and subsequent sepsis

BACKGROUND

In previous studies ketamine was reported to improve survival and decrease serum interleukin-6 (IL-6) concentration after sepsis alone and after burn injury followed by sepsis. The aim of this study was to determine whether ketamine alters survival and/or IL-6 after hemorrhagic shock alone or hemorrhagic shock followed by sepsis.

MATERIALS AND METHODS

Rats were subjected to hemorrhagic shock with or without subsequent Gram-negative bacterial sepsis and were either treated with ketamine 5 mg/kg or were not treated. Blood was sampled for IL-6 determination prior to hemorrhage, at the completion of resuscitation, and at 6 and 30 h later. Mortality was recorded for 7 days following hemorrhage or hemorrhage+sepsis.

RESULTS

After hemorrhage+sepsis the time to median mortality was significantly later in the ketamine-treated group (36 h) than in the control group (12 h). At 12h the survival rate of the ketamine-treated group (100%) was significantly higher than in the control group (55%). There were no significant differences between groups with respect to IL-6 or 7-day survival after either hemorrhage+sepsis or hemorrhage alone.

CONCLUSION

Ketamine improved 12h survival and delayed mortality after hemorrhage+sepsis without significantly altering IL-6, and did not alter survival or IL-6 after hemorrhage alone.

Burn-induced gut barrier injury is attenuated by phosphodiesterase inhibition: effects on tight junction structural proteins

Loss of intestinal barrier function after burn injury allows movement of intraluminal contents across the mucosa, which can lead to the development of distant organ injury and multiple organ failure. Tight junction function is highly regulated by membrane-associated proteins including occludin and zonula occludens protein 1 (ZO-1), which can be modulated by systemic inflammation. We hypothesized that (1) burn injury leads to gut barrier injury, and (2) phosphodiesterase inhibition will attenuate these burn-induced changes. Male balb/c mice undergoing a 30% steam burn were randomized to resuscitation with normal saline or normal saline + pentoxifylline (PTX; 12.5 mg/kg). Intestinal injury was assessed by histological diagnosis and TNF-alpha levels using enzyme-linked immunosorbent assay. Intestinal permeability was assessed by measuring the plasma concentration of fluorescein isothiocyanate-dextran after intraluminal injection in the distal ileum. Occludin and ZO-1 levels were analyzed by immunoblotting and immunohistochemistry. Thirty percent total body surface area (TBSA) burn results in a significant increase in intestinal permeability. Treatment with PTX after burn attenuates intestinal permeability to sham levels. Burn injury resulted in a marked decrease in the levels of tight junction proteins occludin and ZO-1 at 6 and 24 h. The use of PTX after burn significantly decreases the breakdown of occludin and ZO-1. Pentoxifylline also attenuates the burn-induced increase in plasma and intestinal TNF-alpha. Confocal microscopy demonstrates that PTX attenuates the burn-induced reorganization of occludin and ZO-1 away from the tight junction. Pentoxifylline attenuates burn-induced intestinal permeability and decreases the breakdown and reorganization of intestinal occludin and ZO-1. Therefore, phosphodiesterase inhibition may be a useful adjunct strategy in the attenuation of burn-induced gut barrier injury.

Transfusion of blood products in trauma: an update

BACKGROUND

Blood transfusion in the management of severely injured patients can be lifesaving. These patients are susceptible to developing early coagulopathy, thus perpetuating bleeding.

OBJECTIVES

This article presents recent advances in both the civilian and military clinical arena to improve the treatment of trauma patients with severe hemorrhage, the use of agents to support coagulation, perspectives on restrictive transfusion strategies, and transfusion-related risks.

DISCUSSION

Massive blood transfusion is an adjunct to surgical care. The volume of blood products transfused and the ratio of blood components have been associated with increased morbidity and mortality rates. The adverse clinical effects of transfusion and the limited supply of blood products have resulted in modern resuscitation protocols to limit the volume of blood transfused.

CONCLUSION

A restrictive blood transfusion strategy and the use of hemostatic agents may decrease morbidity and mortality in trauma patients, but insufficient data are available for their use in trauma patients. Massive transfusion should reflect an equal ratio of packed red cells and plasma to limit coagulopathy. Prospective randomized trials are needed to standardize an effective protocol.

Pentoxifylline modulates intestinal tight junction signaling after burn injury: effects on myosin light chain kinase

BACKGROUND

Burn injury can result in loss of intestinal barrier function, leading to systemic inflammatory response syndrome and multiorgan failure. Myosin light chain kinase (MLCK), a tight junction protein involved in the regulation of barrier function, increases intestinal epithelial permeability when activated. Prior studies have shown that tumor necrosis factor (TNF)-alpha activates MLCK, in part through a nuclear factor (NF)-kappa B-dependent pathway. We have previously shown that pentoxifylline (PTX) decreases both TNF-alpha synthesis and NF-kappaB activation in models of shock. Therefore, we postulate that PTX will attenuate activation of the tight junction protein MLCK, which may decrease intestinal tight junction permeability after severe burn.

METHODS

Male balb/c mice undergoing a severe burn were randomized to resuscitation with normal saline (NS) or NS + PTX (12.5 mg/kg). Intestinal TNF-alpha levels were evaluated using enzyme linked immunosorbent assay. Gut extracts were obtained to assess MLCK, phosphorylated IKK, IkappaB-alpha, and NF-kappaB p65 levels by immunoblotting.

RESULTS

Burn injury increased intestinal MLCK protein levels threefold in animals resuscitated with NS, whereas those receiving PTX had MLCK levels similar to control (p < 0.01). Treatment with PTX attenuated burn-induced intestinal permeability. PTX decreased cytoplasmic IKK, IkappaB-alpha phosphorylation, and nuclear NF-kappaB p65 translocation to sham levels (p < 0.05 vs. NS).

CONCLUSION

Treatment with PTX attenuates activation of the tight junction protein MLCK, likely through its ability to decrease local TNF-alpha synthesis and NF-kappaB activation after burn. PTX may have therapeutic utility by decreasing intestinal barrier breakdown after burn.

Pentoxifylline modulates intestinal tight junction signaling after burn injury: effects on myosin light chain kinase

BACKGROUND

Burn injury can result in loss of intestinal barrier function, leading to systemic inflammatory response syndrome and multiorgan failure. Myosin light chain kinase (MLCK), a tight junction protein involved in the regulation of barrier function, increases intestinal epithelial permeability when activated. Prior studies have shown that tumor necrosis factor (TNF)-alpha activates MLCK, in part through a nuclear factor (NF)-kappa B-dependent pathway. We have previously shown that pentoxifylline (PTX) decreases both TNF-alpha synthesis and NF-kappaB activation in models of shock. Therefore, we postulate that PTX will attenuate activation of the tight junction protein MLCK, which may decrease intestinal tight junction permeability after severe burn.

METHODS

Male balb/c mice undergoing a severe burn were randomized to resuscitation with normal saline (NS) or NS + PTX (12.5 mg/kg). Intestinal TNF-alpha levels were evaluated using enzyme linked immunosorbent assay. Gut extracts were obtained to assess MLCK, phosphorylated IKK, IkappaB-alpha, and NF-kappaB p65 levels by immunoblotting.

RESULTS

Burn injury increased intestinal MLCK protein levels threefold in animals resuscitated with NS, whereas those receiving PTX had MLCK levels similar to control (p < 0.01). Treatment with PTX attenuated burn-induced intestinal permeability. PTX decreased cytoplasmic IKK, IkappaB-alpha phosphorylation, and nuclear NF-kappaB p65 translocation to sham levels (p < 0.05 vs. NS).

CONCLUSION

Treatment with PTX attenuates activation of the tight junction protein MLCK, likely through its ability to decrease local TNF-alpha synthesis and NF-kappaB activation after burn. PTX may have therapeutic utility by decreasing intestinal barrier breakdown after burn.

The role of erythropoietin in hemorrhagic shock-induced liver and renal injury in rats

INTRODUCTION

The aim of the present study was to evaluate the role of erythropoietin (EPO) in liver and renal injury following hemorrhagic shock (HS) after inhibition of tyrosine kinase activity in rats..

METHODS

Forty-eight Sprague-Dawley rats were assigned to six groups: (I) HS alone; (II) HS followed by retransfusion; (III) EPO and genistein followed by HS; (IV) EPO and genistein followed by HS, followed by retransfusion; (V) HS followed by EPO and genistein; and (VI) HS followed by EPO and genistein, followed by retransfusion. HS was induced for 60 minutes after withdrawal of 30% of the calculated total blood volume of each rat from the left femoral artery. Blood and tissue samples (from the kidney and liver) were obtained 60 minutes after HS in Group I, III, and V; blood and tissue samples were obtained 60 minutes after retransfusion in Group II, IV, and VI. In Group III and IV, EPO was given 60 minutes before HS, and genistein 30 minutes before HS. In Group V and VI, EPO and genistein were given 30 minutes after HS.

RESULTS

Liver and renal injury were significantly attenuated with EPO and genistein administration.

CONCLUSION

These results suggest that EPO is effective in attenuating liver and renal injury in HS, even with inhibition of tyrosine kinase activity with genistein.

Phosphodiesterase inhibition attenuates alterations to the tight junction proteins occludin and ZO-1 in immunostimulated Caco-2 intestinal monolayers

AIMS

Under normal conditions, the intestinal mucosa acts as a local barrier to prevent the influx of luminal contents. The intestinal epithelial tight junction is comprised of several membrane associated proteins, including zonula occludens-1 (ZO-1) and occludin. Disruption of this barrier can lead to the production of pro-inflammatory mediators and ultimately multiple organ failure. We have previously shown that Pentoxifylline (PTX) decreases histologic gut injury and pro-inflammatory mediator synthesis. We hypothesize that PTX prevents the breakdown of ZO-1 and occludin in an in vitro model of immunostimulated intestinal cell monolayers.

MAIN METHODS

Caco-2 human enterocytes were grown as confluent monolayers and incubated under control conditions, or with PTX (2 mM), Cytomix (TNF-alpha, IFN-gamma, IL-1), or Cytomix+PTX for 24 h. Occludin and ZO-1 protein levels were analyzed by Western blot. Confocal microscopy was used to assess the cytoplasmic localization of ZO-1 and occludin.

KEY FINDINGS

Cytomix stimulation of Caco-2 cells resulted in a 50% decrease in both occludin and ZO-1 protein. Treatment with Cytomix+PTX restored both occludin and ZO-1 protein to control levels. Confocal microscopy images show that Cytomix caused an irregular, undulating appearance of ZO-1 and occludin at the cell junctions. Treatment with PTX prevented the Cytomix-induced changes in ZO-1 and occludin localization.

SIGNIFICANCE

Treatment with PTX decreases the pro-inflammatory cytokine induced changes in the intestinal tight junction proteins occludin and ZO-1. Pentoxifylline may be a useful adjunct in the treatment of sepsis and shock by attenuating intestinal barrier breakdown.