Expression of antiapoptotic survivin and aven genes in rat heart tissue after traumatic brain injury

Down-regulation of miR-30b-5p protects cardiomyocytes against hypoxia-induced injury by targeting Aven

Background

Ischemia/hypoxia-induced cardiomyocyte apoptosis has been considered as a main cause of myocardial infarction. Here, we aimed to investigate the functional role of miR-30b-5p in hypoxic cardiomyocytes.

Methods

AC16 human cardiomyocytes were cultured under hypoxia to simulate myocardial infarction. A qRT-PCR assay was performed to determine miR-30b-5p expression in hypoxic cardiomyocytes. Cell survival, injury and apoptosis were assessed by MTT, lactate dehydrogenase (LDH) release, and flow cytometry assays, respectively. The target gene of miR-30b-5p in hypoxic cardiomyocytes was validated by luciferase reporter assay and Western blotting.

Results

MiR-30b-5p expression was found to be significantly upregulated in hypoxic AC16 cells. The in vitro experiments showed that downregulation of miR-30b-5p effectively alleviated hypoxia-induced cardiomyocyte injury. Furthermore, Aven is a potential target gene of miR-30b-5p and its downregulation could partially reverse the influence of miR-30b-5p knockdown on AC16 cells under hypoxia.

Conclusions

Inhibition of miR-30b-5p could protect cardiomyocytes against hypoxia-induced injury by targeting Aven.

Clinical Utility of Survivin (BIRC5), Novel Cardiac Biomarker, as a Prognostic Tool Compared to High-sensitivity C-reactive Protein, Heart-type Fatty Acid Binding Protein and Revised Lee Score in Elderly Patients Scheduled for Major Non-cardiac Surgery: A Prospective Pilot Study

BACKGROUND

Recent studies indicate that survivin (BIRC5) is sensitive to the existence of previous ischemic heart disease, since it is activated in the process of tissue repair and angiogenesis. The aim of this study was to determine the potential of survivin (BIRC5) as a new cardiac biomarker in the preoperative assessment of cardiovascular risk in comparison with clinically accepted cardiac biomarkers and one of the relevant clinical risk scores.

METHODS

We included 79 patients, female (41) and male (38), with the mean age of 71.35±6.89. Inclusion criteria: extensive non-cardiac surgery, general anesthesia, age >55 and at least one of the selected cardiovascular risk factors (hypertension, diabetes mellitus, hyperlipidemia, smoking and positive family history). Exclusion criteria: emergency surgical procedures and inability to understand and sign an informed consent. Blood sampling was performed 7 days prior surgery and levels of survivin (BIRC5), hsCRP and H-FABP were measured.

RESULTS

Revised Lee score was assessed based on data found in patients' history. Levels of survivin (BIRC5) were higher in deceased patients (P<0.05). It showed AUC=0.807 (95% CI, P<0.0005, 0.698-0.917), greater than both H-FABP and revised Lee index, and it increases the mortality prediction when used together with both biomarkers and revised Lee score. The determined cut-off value was 4 pg/mL and 92.86% of deceased patients had an increased level of survivin (BIRC5), (P=0.005).

CONCLUSIONS

Survivin (BIRC5) is a potential cardiac biomarker even in elderly patients without tumor, but it cannot be used independently. Further studies with a greater number of patients are needed.

Anti-edema effects of rhEpo in experimental traumatic brain injury

PURPOSE

Traumatic brain injury (TBI) is one of the leading causes of disability and death which begins with the formation of edema as the persistent primary causative factor in TBI. Although medical management of cerebral edema by hypothermia, ventriculostomy, mannitol or hypertonic saline have been effective in treating edema, many of these therapies end up with some neurologic deficits, necessitating novel treatment options for treating post-TBI edema. This study investigated edema reducing effects of recombinant human Erythropoietin (rhEPO) in reducing acute brain edema in the CCI mouse model of TBI.

METHODS

Anti-edema effects of rhEpo in reducing acute brain edema after injury in the CCI mouse model of TBI were assessed by T2 weighted magnetic resonance imaging (T2wMRI) as the accurate detector of brain edema in correlation with Western blot analysis of cerebral aquaporin 4 (AQP4) index as the critical marker of edema.

RESULTS

Results show that rhEpo treatment significantly reduced brain edema with concomitant reduction in AQP4 immunoexpression in the CCI mouse model of TBI.

CONCLUSION

Current results emphasize clinical utility of rhEpo in treating post-TBI edema.

Effect of recombinant human erythropoietin on serum S100B protein and interleukin-6 levels after traumatic brain injury in the rat

Erythropoietin (EPO) has a neuroprotective effect in the animal model of ischemia/hypoxia, but the mechanisms underlying the EPO effect in traumatic brain injury (TBI) are not well understood. This study examined the potential neuroprotective mechanisms of recombinant human EPO (rhEPO) in rats after TBI. Sixty healthy adult male Sprague-Dawley rats were randomly divided into 5 groups: 1000 U/kg rhEPO-treated, 3000 U/kg rhEPO-treated, 5000 U/kg rhEPO-treated, citicoline, and normal saline (control) groups. The TBI model was based on the modified Feeney's free falling model. Serum samples were collected at 6 hours, 24 hours, 3 days, 5 days, and 7 days after trauma. The serum S100B protein and interleukin-6 (IL-6) levels were measured after treatment in each group with double antibody sandwich enzyme-linked immunosorbent assay. Both serum S100B protein and IL-6 levels were significantly lower in 3000 U/kg rhEPO-treated and 5000 U/kg rhEPO-treated groups (p < 0.001). The decrease in serum S100B protein level was correlated with the dosage of rhEPO. Medium doses of rhEPO achieved the optimum decreases in the serum IL-6 level. Therefore, inhibition of the composition and secretion of S100B protein and IL-6 levels by EPO might be one of the mechanisms involved in decreasing inflammatory reaction in the brain, and may be responsible for the neuroprotective effect after TBI.

Erythropoietin 2nd cerebral protection after acute injuries: a double-edged sword?

Over the past 15 years, a large body of evidence has revealed that the cytokine erythropoietin exhibits non-erythropoietic functions, especially tissue-protective effects. The discovery of EPO and its receptors in the central nervous system and the evidence that EPO is made locally in response to injury as a protective factor in the brain have raised the possibility that recombinant human EPO (rhEPO) could be administered as a cytoprotective agent after acute brain injuries. This review highlights the potential applications of rhEPO as a neuroprotectant in experimental and clinical settings such as ischemia, traumatic brain injury, and subarachnoid and intracerebral hemorrhage. In preclinical studies, EPO prevented apoptosis, inflammation, and oxidative stress induced by injury and exhibited strong neuroprotective and neurorestorative properties. EPO stimulates vascular repair by facilitating endothelial progenitor cell migration into the brain and neovascularisation, and it promotes neurogenesis. In humans, small clinical trials have shown promising results but large prospective randomized studies failed to demonstrate a benefit of EPO for brain protection and showed unwanted side effects, especially thrombotic complications. Recently, regions have been identified within the EPO molecule that mediate tissue protection, allowing the development of non-erythropoietic EPO variants for neuroprotection conceptually devoid of side effects. The efficacy and the safety profile of these new compounds are still to be demonstrated to obtain, in patients, the benefits observed in experimental studies.