Protective effect of erythropoietin on type II pneumocyte cells after traumatic brain injury in rats

Erythropoietin as candidate for supportive treatment of severe COVID-19

In light of the present therapeutic situation in COVID-19, any measure to improve course and outcome of seriously affected individuals is of utmost importance. We recap here evidence that supports the use of human recombinant erythropoietin (EPO) for ameliorating course and outcome of seriously ill COVID-19 patients. This brief expert review grounds on available subject-relevant literature searched until May 14, 2020, including Medline, Google Scholar, and preprint servers. We delineate in brief sections, each introduced by a summary of respective COVID-19 references, how EPO may target a number of the gravest sequelae of these patients. EPO is expected to: (1) improve respiration at several levels including lung, brainstem, spinal cord and respiratory muscles; (2) counteract overshooting inflammation caused by cytokine storm/ inflammasome; (3) act neuroprotective and neuroregenerative in brain and peripheral nervous system. Based on this accumulating experimental and clinical evidence, we finally provide the research design for a double-blind placebo-controlled randomized clinical trial including severely affected patients, which is planned to start shortly.

Acute brain trauma, lung injury, and pneumonia: more than just altered mental status and decreased airway protection

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Even when patients survive the initial insult, there is significant morbidity and mortality secondary to subsequent pulmonary edema, acute lung injury (ALI), and nosocomial pneumonia. Whereas the relationship between TBI and secondary pulmonary complications is recognized, little is known about the mechanistic interplay of the two phenomena. Changes in mental status secondary to acute brain injury certainly impair airway- and lung-protective mechanisms. However, clinical and translational evidence suggests that more specific neuronal and cellular mechanisms contribute to impaired systemic and lung immunity that increases the risk of TBI-mediated lung injury and infection. To better understand the cellular mechanisms of that immune impairment, we review here the current clinical data that support TBI-induced impairment of systemic and lung immunity. Furthermore, we also review the animal models that attempt to reproduce human TBI. Additionally, we examine the possible role of damage-associated molecular patterns, the chlolinergic anti-inflammatory pathway, and sex dimorphism in post-TBI ALI. In the last part of the review, we discuss current treatments and future pharmacological therapies, including fever control, tracheostomy, and corticosteroids, aimed to prevent and treat pulmonary edema, ALI, and nosocomial pneumonia after TBI.

Protective Effects of Alpha-Lipoic Acid on Methotrexate-Induced Oxidative Lung Injury in Rats

OBJECTIVE

Oxidative stress is one of the major causes of methotrexate induced lung injury (MILI). Alpha-lipoic acid (ALA), which occurs naturally in human food, has antioxidative and anti-inflammatory activities. The aim of this study was to research the potential protective role of ALA on MILI in rats.

METHODS

Twenty one rats were randomly subdivided into three groups: control (group I), methotrexate (MTX) treated (group II), and MTX+ALA treated (group III). Lung injury was performed with a single dose of MTX (20 mg/kg) to groups 2 and 3. On the sixth day, animals in all groups were sacrificed by decapitation and lung tissue and blood samples were removed for histological examination and also measurement the levels of interleukin-1-beta (IL-1β), malondialdehyde (MDA), glutathione (GSH), tumour necrosis factor-alpha (TNF-α), myeloperoxidase (MPO), and sodium potassium-adenosine triphosphatase (Na+/K+ATPase).

RESULTS

In MTX group tissue GSH, Na+/K+ATPase activities were lower, tissue MDA, MPO and plasma IL-1?, TNF-? were significantly higher than the other groups. Histopathological examination showed that lung injury was less severe in group 2 according to group 3.

CONCLUSIONS

Oxidative damage of MTX in rat lung is partially reduced when combined with ALA.

Neuropulmonology

Neuropulmonology refers to the complex interconnection between the central nervous system and the respiratory system. Neurologic injury includes traumatic brain injury, hemorrhage, stroke, and seizures, and in each there are far-reaching effects that can result in pulmonary dysfunction. Systemic changes can induce impairment of pulmonary function due to changes in the core structure and function of the lung. The conditions and disorders that often occur in these patients include aspiration pneumonia, neurogenic pulmonary edema, and acute respiratory distress syndrome, but also several abnormal respiratory patterns and sleep-disordered breathing. Lung infections, pulmonary edema - neurogenic or cardiogenic - and pulmonary embolus all are a serious barrier to recovery and can have significant effects on outcomes such as hospital course, prognosis, and mortality. This review presents the spectrum of pulmonary abnormalities seen in neurocritical care.

What's New in Traumatic Brain Injury: Update on Tracking, Monitoring and Treatment

Traumatic brain injury (TBI), defined as an alteration in brain functions caused by an external force, is responsible for high morbidity and mortality around the world. It is important to identify and treat TBI victims as early as possible. Tracking and monitoring TBI with neuroimaging technologies, including functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), positron emission tomography (PET), and high definition fiber tracking (HDFT) show increasing sensitivity and specificity. Classical electrophysiological monitoring, together with newly established brain-on-chip, cerebral microdialysis techniques, both benefit TBI. First generation molecular biomarkers, based on genomic and proteomic changes following TBI, have proven effective and economical. It is conceivable that TBI-specific biomarkers will be developed with the combination of systems biology and bioinformation strategies. Advances in treatment of TBI include stem cell-based and nanotechnology-based therapy, physical and pharmaceutical interventions and also new use in TBI for approved drugs which all present favorable promise in preventing and reversing TBI.

Protective effects of erythropoietin and N-acetylcysteine on methotrexate-induced lung injury in rats

OBJECTIVE

Methotrexate (MTX) is known to have deleterious side effects on lung tissue. We aimed to investigate the effects of erythropoietin (EPO) and N-acetyl-cysteine (NAC) on MTX-induced lung injury in rats.

STUDY DESIGN

Animal experiment.

MATERIAL AND METHODS

Twenty-six female Sprague-Dawley rats were divided into 4 groups. Sham group, 0.3 mL saline; MTX group, 5 mg/kg MTX; EPO group, 5mg/kg MTX and 2000 IU/kg EPO; NAC group, 5 mg/kg MTX and 200 mg/kg NAC were administered once daily for 4 consecutive days. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and inflammation and congestion scores in lung tissues were evaluated.

RESULTS

In MTX group MDA were significantly higher, CAT and SOD were significantly lower than in sham, EPO and NAC groups (p<0.005). In EPO group MDA, CAT, and SOD were higher, but not significant than those in group NAC (p>0.005). In group MTX both scores were significantly higher than in sham (p<0.005). The congestion score of group MTX was significantly higher than those of group EPO and NAC (p<0.005).

CONCLUSION

EPO and NAC have significant preventive effects on MTX-induced lung injury in rats. Decreased antioxidant capacity and increased MDA level may cause the oxidative damage in MTX group. Also, higher antioxidant capacity and lower MDA level may be a response to oxidative stress in EPO and NAC groups.

Improved cerebrovascular function and reduced histological damage with darbepoietin alfa administration after cortical impact injury in rats

Darbepoetin alfa (darbEpo) is an erythropoietic glycoprotein that activates the erythropoietin receptor. The aim of our study was to determine whether darbEpo is neuroprotective in a cortical impact injury (CII) model and to determine the characteristics of dose response and time window. To better understand the vascular mechanism of darbEpo neuroprotection, the reactivity of cerebral blood flow (CBF) to l-arginine administration was also studied. Rats were given saline or darbEpo from 2.5 to 50 μg/kg at 5 min after CII or a dose of 25 μg/kg darbEpo at times ranging from 5 min to 24 h after CII. Histological assessment was determined 2 weeks after a severe CII. Other rats were given either darbEpo (25 μg/kg) or saline daily for 3 days before injury. Five minutes after severe CII, they were given either l-arginine or d-arginine. Hemodynamic variables were monitored for 2 h after injury. In the dose-response study, darbEpo in doses of 25 and 50 μg/kg significantly reduced contusion volume from 39.1 ± 6.7 to 8.1 ± 3.1 and 11.2 ± 6.0 mm(3), respectively. In the time window study, darbEpo reduced contusion volume when given in a dose of 25 μg/kg at 5 min to 6 h after the impact injury. In animals pretreated with darbEpo, the CBF response to l-arginine was significantly greater than in the animals pretreated with saline. These data demonstrate that darbEpo has neuroprotective effects in traumatic brain injury in a dose- and time-dependent manner and that vascular effects of darbEpo may have a role in neuroprotection.

Erythropoetin as a novel agent with pleiotropic effects against acute lung injury

Current pharmacotherapy for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is not optimal, and the biological and physiological complexity of these severe lung injury syndromes requires consideration of combined-agent treatments or agents with pleiotropic action. In this regard, exogenous erythropoietin (EPO) represents a possible candidate since a number of preclinical studies have revealed beneficial effects of EPO administration in various experimental models of ALI. Taken together, this treatment strategy is not a single mediator approach, but it rather provides protection by modulating multiple levels of early signaling pathways involved in apoptosis, inflammation, and peroxidation, potentially restoring overall homeostasis. Furthermore, EPO appears to confer vascular protection by promoting angiogenesis. However, only preliminary studies exist and more experimental and clinical studies are necessary to clarify the efficacy and potentially cytoprotective mechanisms of EPO action. In addition to the attempts to optimize the dose and timing of EPO administration, it would be of great value to minimize any potential toxicity, which is essential for EPO to fulfill its role as a potential candidate for the treatment of ALI in routine clinical practice. The present article reviews recent advances that have elucidated biological and biochemical activities of EPO that may be potentially applicable for ALI/ARDS management.

Diffuse cellular and fibrosing interstitial pneumonitis with desquamative interstitial pneumonitis-like features associated with myeloid neoplasia

Patients with preleukemic myeloid neoplasia can develop nonhematologic disease. Five patients with the myelodysplastic syndrome presented with interstitial lung disease that heralded acute leukemia in 3. Chest radiographs showed diffuse interstitial opacities, and the lung biopsies showed diffuse cellular interstitial and fibrosing pneumonitis with prominent alveolar filling by macrophages. There was no evidence to support a drug-induced or infectious etiology, and all cases lacked an identifiable leukemic infiltration. The inflammatory infiltrates and fibrosis were analyzed morphometrically, and this revealed a trend toward an indirect correlation between both CD68 cells and MPO-positive inflammatory cells and pulmonary fibrosis. We conclude that preleukemic myeloid neoplasia can be associated with an interstitial pneumonitis with histopathologic features that are distinguishable from both leukemic infiltration and "usual" nonspecific interstitial pneumonia.

Erythropoietin inhibits the increase of intestinal labile zinc and the expression of inflammatory mediators after traumatic brain injury in rats

BACKGROUND

The objective of this study was to determine the effect of erythropoietin (Epo) on the intestinal labile zinc and the inflammatory factor in rats after traumatic brain injury (TBI).

METHODS

Male Sprague-Dawley rats were randomly divided into nine groups: (a) normal group; (b) sham-operation group; (c, d, e, f, and g) TBI group, killed at 1 hour, 6 hour, 24 hour, and 72 hour and 7 days postinjury, respectively; (h and i) TBI + saline and TBI + Epo, killed at 24 hour or 72 hour postinjury. Parietal brain contusion was produced by a free-falling weight on the exposed dura of the right parietal lobe. Intestinal labile zinc, the tumor necrosis factor-alpha, interleukin (IL)-8, and wet/dry weight ratio were investigated in different groups.

RESULTS

The gut contains a certain amount of labile zinc in normal animals and TBI caused obviously gradual increment of intestinal liabled zinc. The levels of inflammatory mediators and the gut wet/dry weight ratio were also found to increase in the trauma group (p < 0.05). There was a highly positive correlation between the abundance of zinc fluorescence and these proinflammation factors. Epo significantly reduced the intestinal labile zinc, the inflammatory mediators, and the gut wet/dry weight ratio compared with TBI group (p < 0.05).

CONCLUSIONS

Epo can protect intestine from TBI-induced injury by attenuating intestinal inflammation and labile zinc accumulation in vivo.

Erythropoietin attenuates ischemia-reperfusion induced lung injury by inhibiting tumor necrosis factor-alpha and matrix metalloproteinase-9 expression

Erythropoietin (Epo) was recently defined as an endogenous agent with more than hematopoietic functions. Previously we explored the potential of this agent to ameliorate lung ischemia-reperfusion (I/R) injury. The present study aims to determine the optimal dose and timing of administration for improving lung injury, and to further investigate the mechanisms by which Epo ameliorates lung I/R injury. The left lungs of Sprague-Dawley rats underwent 90 min ischemia and 120 min reperfusion. Firstly, animals in different groups were intraperitoneally injected with various doses of recombined human erythropoietin (rhEpo) 24 h prior to operation, 2 h prior to operation, or after the onset of reperfusion. Pulmonary myeloperoxidase (MPO) activity and malondialdehyde (MDA) content were evaluated. Treatment with 3 KU/kg rhEpo 2 h prior to operation was optimal for attenuating pulmonary MPO activity and MDA content. With such treatment, ultrastructural changes of pneumocytes were observed, and the pneumocyte apoptosis index was also determined by terminal dUTP nick-end labeling method. The plasma concentrations of tumor necrosis factor (TNF)-alpha and matrix metalloproteinase (MMP)-9 were evaluated by enzyme-linked immunosorbent assay, and pulmonary expression by immunohistochemistry. When pretreated with rhEpo, the pneumocyte ultrastructure was predominantly maintained and the pulmonary apoptosis index was markedly reduced. In comparison with untreated animals, in treated animals the plasma concentrations of TNF-alpha and MMP-9 were significantly decreased, and their expression in lung tissue was markedly reduced as well. The results indicated that Epo potently protected against lung I/R injury by inhibiting systemic and local expression of TNF-alpha and MMP-9.

Erythropoietin attenuates lung injury in lipopolysaccharide treated rats

BACKGROUND

Erythropoietin (EPO) elicits protective effects in lung ischemia-reperfusion, hyperoxia, acute necrotizing pancreatitis, and some other tissues. In the present study, we investigated the possible protective roles of EPO in the lipopolysaccharide (LPS) induced lung injury.

MATERIALS AND METHODS

Male Sprague-Dawley rats were treated with EPO (3000 U/kg, i.p.) or vehicle (saline), 30 min prior to LPS administration (6 mg/kg, i.v.). Four h following LPS injection, samples of pulmonary tissue were collected. Optical microscopy was performed to examine pathological changes in lungs. Validated methods were used to measure wet/dry ratios (W/D), myeloperoxidase (MPO) activity, malondialdehyde (MDA) concentrations, and nitrite/nitrate (NO(2)(-)/NO(3)(-)) levels in lungs. Western blotting was performed to study the pulmonary expression of inducible nitric oxide synthase (iNOS) and nitrotyrosine protein.

RESULTS

Pretreatment with EPO led to (1) significant attenuation of endotoxemia induced evident lung histologic injury and edema; (2) inhibition of LPS mediated induction in MPO activity and MDA concentration; (3) inhibition of LPS mediated overproduction of pulmonary NO(2)(-)/NO(3)(-) levels; and (4) marked suppression in endotoxin induced expression of iNOS and nitrotyrosine.

CONCLUSIONS

This study provides considerable evidence that EPO has an ability to significantly attenuate endotoxin-induced acute lung injury in rats.

Protective effects of erythropoietin against acute lung injury in a rat model of acute necrotizing pancreatitis

AIM

To investigate the effect of exogenous erythro-poietin (EPO) administration on acute lung injury (ALI) in an experimental model of sodium taurodeoxycholate- induced acute necrotizing pancreatitis (ANP).

METHODS

Forty-seven male Wistar albino rats were randomly divided into 7 groups: sham group (n = 5), 3 ANP groups (n = 7 each) and 3 EPO groups (n = 7 each). ANP was induced by retrograde infusion of 5% sodium taurodeoxycholate into the common bile duct. Rats in EPO groups received 1000 U/kg intramuscular EPO immediately after induction of ANP. Rats in ANP groups were given 1 mL normal saline instead. All animals were sacrificed at postoperative 24 h, 48 h and 72 h. Serum amilase, IL-2, IL-6 and lung tissue malondialdehyde (MDA) were measured. Pleural effusion volume and lung/body weight (LW/BW) ratios were calculated. Tissue levels of TNF-alpha, IL-2 and IL-6 were screened immunohistochemically. Additionally, ox-LDL accumulation was assessed with immune-fluorescent staining. Histopathological alterations in the lungs were also scored.

RESULTS

The mean pleural effusion volume, calculated LW/BW ratio, serum IL-6 and lung tissue MDA levels were significantly lower in EPO groups than in ANP groups. No statistically significant difference was observed in either serum or tissue values of IL-2 among the groups. The level of tumor necrosis factor-alpha (TNF-alpha) and IL-6 and accumulation of ox-LDL were evident in the lung tissues of ANP groups when compared to EPO groups, particularly at 72 h. Histopathological evaluation confirmed the improvement in lung injury parameters after exogenous EPO administration, particularly at 48 h and 72 h.

CONCLUSION

EPO administration leads to a significant decrease in ALI parameters by inhibiting polymorphonuclear leukocyte (PMNL) accumulation, decreasing the levels of proinflammatory cytokines in circulation, preserving microvascular endothelial cell integrity and reducing oxidative stress-associated lipid peroxidation and therefore, can be regarded as a cytoprotective agent in ANP-induced ALI.

Protective effects of erythropoietin against acute lung injury in a rat model of acute necrotizing pancreatitis

AIM: To investigate the effect of exogenous erythro-poietin (EPO) administration on acute lung injury (ALI) in an experimental model of sodium taurodeoxycholate-induced acute necrotizing pancreatitis (ANP).

METHODS: Forty-seven male Wistar albino rats were randomly divided into 7 groups: sham group (n = 5), 3 ANP groups (n = 7 each) and 3 EPO groups (n = 7 each). ANP was induced by retrograde infusion of 5% sodium taurodeoxycholate into the common bile duct. Rats in EPO groups received 1000 U/kg intramuscular EPO immediately after induction of ANP. Rats in ANP groups were given 1 mL normal saline instead. All animals were sacrificed at postoperative 24 h, 48 h and 72 h. Serum amilase, IL-2, IL-6 and lung tissue malondialdehyde (MDA) were measured. Pleural effusion volume and lung/body weight (LW/BW) ratios were calculated. Tissue levels of TNF-α, IL-2 and IL-6 were screened immunohistochemically. Additionally, ox-LDL accumulation was assessed with immune-fluorescent staining. Histopathological alterations in the lungs were also scored.

RESULTS: The mean pleural effusion volume, calculated LW/BW ratio, serum IL-6 and lung tissue MDA levels were significantly lower in EPO groups than in ANP groups. No statistically significant difference was observed in either serum or tissue values of IL-2 among the groups. The level of tumor necrosis factor-α (TNF-α) and IL-6 and accumulation of ox-LDL were evident in the lung tissues of ANP groups when compared to EPO groups, particularly at 72 h. Histopathological evaluation confirmed the improvement in lung injury parameters after exogenous EPO administration, particularly at 48 h and 72 h.

CONCLUSION: EPO administration leads to a significant decrease in ALI parameters by inhibiting polymorphonuclear leukocyte (PMNL) accumulation, decreasing the levels of proinflammatory cytokines in circulation, preserving microvascular endothelial cell integrity and reducing oxidative stress-associated lipid peroxidation and therefore, can be regarded as a cytoprotective agent in ANP-induced ALI.

Inhibitory effect on cerebral inflammatory agents that accompany traumatic brain injury in a rat model: a potential neuroprotective mechanism of recombinant human erythropoietin (rhEPO)

Erythropoietin (EPO) has recently been shown to have a neuroprotective effect in animal models of traumatic brain injury (TBI). However, the precise mechanisms remain unclear. Cerebral inflammation plays an important role in the pathogenesis of secondary brain injury after TBI. We, therefore, tried to analyze how recombinant human erythropoietin (rhEPO) might effect the inflammation-related factors common to TBI: nuclear factor kappa B (NF-kappaB), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) in a rat TBI model. Male rats were given 0 or 5000 units/kg injections of rhEPO 1h post-injury and on days 1, 2 and 3 after surgery. Brain samples were extracted at 3 days after trauma. We measured NF-kappaB by electrophoretic mobility shift assay (EMSA); IL-1beta, TNF-alpha and IL-6 by enzyme-linked immunosorbent assay (ELISA); ICAM-1 by immunohistochemistry; brain edema by wet/dry method; blood-brain barrier (BBB) permeability by Evans blue extravasation and cortical apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method. We found that NF-kappaB, pro-inflammatory cytokines and ICAM-1 were increased in all injured animals. In animals given rhEPO post-TBI, NF-kappaB, IL-1beta, TNF-alpha and ICAM-1 were decreased in comparison to vehicle-treated animals. Measures of IL-6 showed no change after rhEPO treatment. Administration of rhEPO reduced brain edema, BBB permeability and apoptotic cells in the injured brain. In conclusion, post-TBI rhEPO administration may attenuate inflammatory response in the injured rat brain, and this may be one mechanism by which rhEPO improves outcome following TBI.