Erythropoietin in patients with traumatic brain injury and extracranial injury-A post hoc analysis of the erythropoietin traumatic brain injury trial

Neuroprotective and neuroregenerative drugs after severe traumatic brain injury : A narrative review from a clinical perspective

Traumatic brain injuries cause enormous individual and socioeconomic burdens. Survivors frequently struggle with motor handicaps as well as impaired cognition and emotion. In addition to the primary mechanical brain damage, complex secondary mechanisms are the main drivers of functional impairment. Many of these pathophysiological mechanisms are now well known: excitotoxic amino acids, breakdown of the blood-brain barrier, neuroinflammation with subsequent damage to cell organelles and membranes, cerebral edema, and apoptotic processes triggering neuronal death; however, paracrine resilience factors may counteract these processes. Specific neuroprotective and neuroregenerative intensive care therapies are few. This review highlights medical approaches aimed at mitigating secondary damage and promoting neurotrophic processes in severe traumatic brain injury. Some pharmacologic attempts that appeared very promising in experimental settings have had disappointing clinical results (progesterone, cyclosporine A, ronopterin, erythropoietin, dexanabinol). Thus, the search for drugs that can effectively limit ongoing posttraumatic neurological damage is ongoing. Some medications appear to be beneficial: N‑methyl-D-aspartate receptor (NMDA) antagonists (esketamine, amantadine, Mg++) reduce excitotoxicity and statins and cerebrolysin are known to counteract neuroinflammation. By supporting the impaired mitochondrial energy supply, oxidative processes are inhibited and neuroregenerative processes, such as neurogenesis, angiogenesis and synaptogenesis are promoted by citicoline and cerebrolysin. First clinical evidence shows an improvement in cognitive and thymopsychic outcomes, underlined by own clinical experience combining different therapeutic approaches. Accordingly, adjuvant treatment with neuroprotective substances appears to be a promising option, although more randomized prospective studies are still needed.

A Modern Approach to the Treatment of Traumatic Brain Injury

Background: Traumatic brain injury manifests itself in various forms, ranging from mild impairment of consciousness to severe coma and death. Traumatic brain injury remains one of the leading causes of morbidity and mortality. Currently, there is no therapy to reverse the effects associated with traumatic brain injury. New neuroprotective treatments for severe traumatic brain injury have not achieved significant clinical success. Methods: A literature review was performed to summarize the recent interdisciplinary findings on management of traumatic brain injury from both clinical and experimental perspective. Results: In the present review, we discuss the concepts of traditional and new approaches to treatment of traumatic brain injury. The recent development of different drug delivery approaches to the central nervous system is also discussed. Conclusions: The management of traumatic brain injury could be aimed either at the pathological mechanisms initiating the secondary brain injury or alleviating the symptoms accompanying the injury. In many cases, however, the treatment should be complex and include a variety of medical interventions and combination therapy.

Reimagining old drugs with new tricks: Mechanisms, strategies and notable success stories in drug repurposing for neurological diseases

Recent evolution in drug repurposing has brought new anticipation, especially in the conflict against neurodegenerative diseases (NDDs). The traditional approach to developing novel drugs for these complex disorders is laborious, time-consuming, and often abortive. However, drug reprofiling which is the implementation of illuminating novel therapeutic applications of existing approved drugs, has shown potential as a promising strategy to accelerate the hunt for therapeutics. The advancement of computational approaches and artificial intelligence has expedited drug repurposing. These progressive technologies have enabled scientists to analyse extensive datasets and predict potential drug-disease interactions. By prospecting into the existing pharmacological knowledge, scientists can recognise potential therapeutic candidates for reprofiling, saving precious time and resources. Preclinical models have also played a pivotal role in this field, confirming the effectiveness and mechanisms of action of repurposed drugs. Several studies have occurred in recent years, including the discovery of available drugs that demonstrate significant protective effects in NDDs, relieve debilitating symptoms, or slow down the progression of the disease. These findings highlight the potential of repurposed drugs to change the landscape of NDD treatment. Here, we present an overview of recent developments and major advances in drug repurposing intending to provide an in-depth analysis of traditional drug discovery and the strategies, approaches and technologies that have contributed to drug repositioning. In addition, this chapter attempts to highlight successful case studies of drug repositioning in various therapeutic areas related to NDDs and explore the clinical trials, challenges and limitations faced by researchers in the field. Finally, the importance of drug repositioning in drug discovery and development and its potential to address discontented medical needs is also highlighted.

A comprehensive review of capillary electrophoresis-based techniques for erythropoietin isoforms analysis

Different CE techniques have been used to analyze erythropoietin. These techniques have been shown to be effective in differentiating and quantifying erythropoietin isoforms, including natural and recombinant origins. This review provides a comprehensive overview of various capillary electrophoresis-based techniques used for the analysis of erythropoietin isoforms. The importance of erythropoietin in clinical practice and the necessity for the accurate analysis of its isoforms are first discussed. Various techniques that have been used for erythropoietin isoform analysis are then described. The main body of the review focuses on the different capillary electrophoresis-based methods that have been developed for erythropoietin isoform analysis, including capillary zone electrophoresis and capillary isoelectric focusing. The advantages and drawbacks of each method as well as their applications are discussed. Suggestions into the future directions of the area are also described.

The effect of recombinant erythropoietin on long-term outcome after moderate-to-severe traumatic brain injury

PURPOSE

Recombinant erythropoietin (EPO) administered for traumatic brain injury (TBI) may increase short-term survival, but the long-term effect is unknown.

METHODS

We conducted a pre-planned long-term follow-up of patients in the multicentre erythropoietin in TBI trial (2010-2015). We invited survivors to follow-up and evaluated survival and functional outcome with the Glasgow Outcome Scale-Extended (GOSE) (categories 5-8 = good outcome), and secondly, with good outcome determined relative to baseline function (sliding scale). We used survival analysis to assess time to death and absolute risk differences (ARD) to assess favorable outcomes. We categorized TBI severity with the International Mission for Prognosis and Analysis of Clinical Trials in TBI model. Heterogeneity of treatment effects were assessed with interaction p-values based on the following a priori defined subgroups, the severity of TBI, and the presence of an intracranial mass lesion and multi-trauma in addition to TBI.

RESULTS

Of 603 patients in the original trial, 487 patients had survival data; 356 were included in the follow-up at a median of 6 years from injury. There was no difference between treatment groups for patient survival [EPO vs placebo hazard ratio (HR) (95% confidence interval (CI) 0.73 (0.47-1.14) p = 0.17]. Good outcome rates were 110/175 (63%) in the EPO group vs 100/181 (55%) in the placebo group (ARD 8%, 95% CI [Formula: see text] 3 to 18%, p = 0.14). When good outcome was determined relative to baseline risk, the EPO groups had better GOSE (sliding scale ARD 12%, 95% CI 2-22%, p = 0.02). When considering long-term patient survival, there was no evidence for heterogeneity of treatment effect (HTE) according to severity of TBI (p = 0.85), presence of an intracranial mass lesion (p = 0.48), or whether the patient had multi-trauma in addition to TBI (p = 0.08). Similarly, no evidence of treatment heterogeneity was seen for the effect of EPO on functional outcome.

CONCLUSION

EPO neither decreased overall long-term mortality nor improved functional outcome in moderate or severe TBI patients treated in the intensive care unit (ICU). The limited sample size makes it difficult to make final conclusions about the use of EPO in TBI.

Beyond the Brain: Peripheral Interactions after Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability, and there are currently no pharmacological treatments known to improve patient outcomes. Unquestionably, contributing toward a lack of effective treatments is the highly complex and heterogenous nature of TBI. In this review, we highlight the recent surge of research that has demonstrated various central interactions with the periphery as a potential major contributor toward this heterogeneity and, in particular, the breadth of research from Australia. We describe the growing evidence of how extracranial factors, such as polytrauma and infection, can significantly alter TBI neuropathology. In addition, we highlight how dysregulation of the autonomic nervous system and the systemic inflammatory response induced by TBI can have profound pathophysiological effects on peripheral organs, such as the heart, lung, gastrointestinal tract, liver, kidney, spleen, and bone. Collectively, this review firmly establishes TBI as a systemic condition. Further, the central and peripheral interactions that can occur after TBI must be further explored and accounted for in the ongoing search for effective treatments.

The effect of doxycycline on neuron-specific enolase in patients with traumatic brain injury: a randomized controlled trial

Objective:

We aimed to examine the effect of doxycycline on serum levels of neuron-specific enolase (NSE), a marker of neuronal damage in traumatic brain injury (TBI) patients.

Methods:

Patients were randomly assigned into two groups (n = 25 each) to receive either placebo or doxycycline (200 mg daily), with their standard management for 7 days.

Results:

NSE serum levels in the doxycycline and control groups on day 3 were 14.66 ± 1.78 versus 18.09 ± 4.38 ng/mL, respectively (p = 0.008), and on day 7 were 12.3 ± 2.0 versus 16.43 ± 3.85 ng/mL, respectively (p = 0.003). Glasgow Coma Scale (GCS) on day 7 was 11.90 ± 2.83 versus 9.65 ± 3.44 in the doxycycline and control groups, respectively (p = 0.031). NSE serum levels and GCS scores were negatively correlated (r = −0.569, p < 0.001).

Conclusion:

Adjunctive early use of doxycycline might be a novel option that halts the ongoing secondary brain injury in patients with moderate to severe TBI. Future larger clinical trials are warranted to confirm these findings.

Meta-Analysis with Trial Sequential Analysis on the Efficacy and Safety of Erythropoietin in Traumatic Brain Injury: A New Paradigm

OBJECTIVE

Erythropoietin (EPO) has been shown to be beneficial in traumatic brain injury (TBI). We have attempted to quantitatively synthesize the findings of current randomized controlled trials (RCTs) in this meta-analysis and analyzed the need for further trials using trial sequential analysis (TSA).

METHODS

A systematic search was performed in PubMed, the Cochrane Library databases, and Google Scholar for RCTs until December 2019 evaluating the role of EPO in patients with TBI. Seven RCTs were finally included in the quantitative analysis. TSA was done to evaluate the need for further studies.

RESULTS

The pooled estimate demonstrated that EPO significantly reduced mortality at 6 months (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.43-0.97; P = 0.04) but not in hospital mortality (OR, 0.84; 95% CI, 0.31-2.32; P = 0.74). There was no significant difference in the rate of favorable outcomes with EPO (OR, 1.58; 95% CI, 0.84-2.99; P = 0.16). The rate of deep vein thrombosis (RD, -0.02; 95% CI, -0.06 to 0.02; P =0.41) was also not found to be significantly different in the 2 groups. TSA showed that the accrued information is insufficient to make any definitive conclusions.

CONCLUSIONS

EPO seems to be beneficial in terms of reducing 6-month mortality, however, its effect on in-hospital mortality, neurologic outcomes, and risk of deep vein thrombosis fails to reach statistical significance. TSA suggests a need for large trials to evaluate the role of EPO in patients with TBI in a more systematic way.

Erythropoietin attenuates propofol-induced hippocampal neuronal cell injury in developing rats by inhibiting toll-like receptor 4 expression

BACKGROUND

This study was to investigate the neuroprotective effect of erythropoietin (EPO) on hippocampal neuronal cell injury in developing rats.

METHODS

The hippocampal neurons cells were obtained from SD rats aged 10 days and divided into control, propofol, EPO, and propofol + erythropoietin (E + P) groups. Cell proliferation and apoptosis were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Ki-67 immunofluorescence, and flow cytometry, respectively. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-4 and IL-10 were detected by enzyme-linked immunosorbent assay (ELISA). Cellular immunohistochemistry was utilized to detect the expression of proliferating cell nuclear antigen (PCNA), nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3). Quantitative real time polymerase chain reaction (qRT-PCR) and western blot were used to detect the expression of Bax, Bcl-2, Caspase-3, toll-like receptor 4 (TLR4) and p65. Furthermore, TLR4 antagonist (TAK-242) and activator (LPS) were used to study the relationship between EPO and TLR4.

RESULTS

Propofol treatment caused morphological and structural damage of hippocampal neurons. However, EPO significantly improved this damage, enhanced cell proliferation, decreased apoptosis and pro-inflammatory factor content, up-regulated the expression of Ki-67, PCNA, Bcl-2, NGF, BDNF and NT-3, as well as decreased the expression of Bax, Caspase-3, TLR4 and p65 (p < 0.05). After TAK-242 or LPS treatment, it showed similar results in propofol + TAK-242 (T + P) group and E + P group.

CONCLUSION

Erythropoietin could attenuate propofol-induced hippocampal neuronal cell injury in developing rats, which may be related to inhibit TLR4 expression.

Anesthetic considerations for extracranial injuries in patients with associated brain trauma

Patients with severe traumatic brain injury often presents with extracranial injuries, which may contribute to fatal outcome. Anesthetic management of such polytrauma patients is extremely challenging that includes prioritizing the organ system to be dealt first, reducing on-going injury, and preventing secondary injuries. Neuroprotective and neurorescue measures should be instituted simultaneously during extracranial surgeries. Selection of anesthetic drugs that minimally interferes with cerebral dynamics, maintenance of hemodynamics and cerebral perfusion pressure, optimal utilization of multimodal monitoring techniques, and aggressive rehabilitation approach are the key factors for improving overall patient outcome.

Mitochondrial dysfunctioning and neuroinflammation: Recent highlights on the possible mechanisms involved in Traumatic Brain Injury

Traumatic brain injury (TBI) is the injury to the vasculature of brain while trauma caused by physical, chemical and biological stimuli. TBI is the leading cause of mortality and morbidity around the world. In this, primary insult leads to secondary injury through the involvement and initiation of various pathological processes. The most citable includes excitotoxicity, Blood Brain Barrier (BBB) dysfunction, inflammation, mitochondrial dysfunction, oxidative stress, calcium efflux, microglial mediated release of proinflammatory mediators (cytokine, chemokines, interleukin, tissue necrosis factor etc.). The morphological changes in TBI are proportional to mitochondrial dysfunctioning and microglial activation, which play an assorted role in neurodegeneration following traumatic brain injury. It is also assumed that the release of nitric oxide, activation of microglial cells plays a diversive role in maintaining the physiological and pathological balance. This review cites different pathophysiological mechanisms that are involved in progenesis of secondary injury after primary insult. These targets further are useful to explore the deep molecular mechanisms and to analyse the effectiveness of available drugs. Moreover, the present review reflects the underlying inflammatory cascade responsible for neuronal loss and neurological deficit in TBI.

Time to reconsider extended erythropoietin treatment for infantile traumatic brain injury?

Pediatric traumatic brain injury (TBI) remains a leading cause of childhood morbidity and mortality worldwide. Most efforts to reduce the chronic impact of pediatric TBI involve prevention and minimization of secondary injury. Currently, no treatments are used in routine clinical care during the acute and subacute phases to actively repair injury to the developing brain. The endogenous pluripotent cytokine erythropoietin (EPO) holds promise as an emerging neuroreparative agent in perinatal brain injury (PBI). EPO signaling in the central nervous system (CNS) is essential for multiple stages of neurodevelopment, including the genesis, survival and differentiation of multiple lineages of neural cells. Postnatally, EPO signaling decreases markedly as the CNS matures. Importantly, high-dose, extended EPO regimens have shown efficacy in preclinical controlled cortical impact (CCI) models of infant TBI at two different, early ages by independent research groups. Specifically, extended high-dose EPO treatment after infantile CCI prevents long-term cognitive deficits in adult rats. Because of the striking differences in the molecular and cellular responses to both injury and recovery in the developing and mature CNS, and the excellent safety profile of EPO in infants and children, extended courses of EPO are currently in Phase III trials for neonates with PBI. Extended, high-dose EPO may also warrant testing for infants and young children with TBI.

The complexity of neuroinflammation consequent to traumatic brain injury: from research evidence to potential treatments

This review recounts the definitions and research evidence supporting the multifaceted roles of neuroinflammation in the injured brain following trauma. We summarise the literature fluctuating from the protective and detrimental properties that cytokines, leukocytes and glial cells play in the acute and chronic stages of TBI, including the intrinsic factors that influence cytokine responses and microglial functions relative to genetics, sex, and age. We elaborate on the pros and cons that cytokines, chemokines, and microglia play in brain repair, specifically neurogenesis, and how such conflicting roles may be harnessed therapeutically to sustain the survival of new neurons. With a brief review of the clinical and experimental findings demonstrating early and chronic inflammation impacts on outcomes, we focus on the clinical conditions that may be amplified by neuroinflammation, ranging from acute seizures to chronic epilepsy, neuroendocrine dysfunction, dementia, depression, post-traumatic stress disorder and chronic traumatic encephalopathy. Finally, we provide an overview of the therapeutic agents that have been tested to reduce inflammation-driven secondary pathological cascades and speculate the future promise of alternative drugs.

Erythropoietin in Critical Illness and Trauma

Erythropoietin (EPO) is a 34kD pleiotropic cytokine that was first identified as being essential for red blood cell (RBC) production. It is now recognized however that EPO is produced by many tissues. It plays a key role in the modulation of the response to injury, inflammation, and tissue hypoxia via the inhibition of apoptosis. Large clinical trials in the critically ill failed to demonstrate a role for EPO as an RBC transfusion sparing agent; however, improved clinical outcomes, attributable to EPO role in tissue protection are observed in critically ill trauma patients. Further research to confirm or refute these observations is required.

Current understanding of neuroinflammation after traumatic brain injury and cell-based therapeutic opportunities

Traumatic brain injury (TBI) remains a major cause of death and disability worldwide. Increasing evidence indicates that TBI is an important risk factor for neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and chronic traumatic encephalopathy. Despite improved supportive and rehabilitative care of TBI patients, unfortunately, all late phase clinical trials in TBI have yet to yield a safe and effective neuroprotective treatment. The disappointing clinical trials may be attributed to variability in treatment approaches and heterogeneity of the population of TBI patients as well as a race against time to prevent or reduce inexorable cell death. TBI is not just an acute event but a chronic disease. Among many mechanisms involved in secondary injury after TBI, emerging preclinical studies indicate that posttraumatic prolonged and progressive neuroinflammation is associated with neurodegeneration which may be treatable long after the initiating brain injury. This review provides an overview of recent understanding of neuroinflammation in TBI and preclinical cell-based therapies that target neuroinflammation and promote functional recovery after TBI.