Hypothermia ameliorates blast-related lifespan reduction of C. elegans

Recent insights from non-mammalian models of brain injuries: an emerging literature

Traumatic brain injury (TBI) is a major global health concern and is increasingly recognized as a risk factor for neurodegenerative diseases including Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). Repetitive TBIs (rTBIs), commonly observed in contact sports, military service, and intimate partner violence (IPV), pose a significant risk for long-term sequelae. To study the long-term consequences of TBI and rTBI, researchers have typically used mammalian models to recapitulate brain injury and neurodegenerative phenotypes. However, there are several limitations to these models, including: (1) lengthy observation periods, (2) high cost, (3) difficult genetic manipulations, and (4) ethical concerns regarding prolonged and repeated injury of a large number of mammals. Aquatic vertebrate model organisms, including Petromyzon marinus (sea lampreys), zebrafish (Danio rerio), and invertebrates, Caenorhabditis elegans (C. elegans), and Drosophila melanogaster (Drosophila), are emerging as valuable tools for investigating the mechanisms of rTBI and tauopathy. These non-mammalian models offer unique advantages, including genetic tractability, simpler nervous systems, cost-effectiveness, and quick discovery-based approaches and high-throughput screens for therapeutics, which facilitate the study of rTBI-induced neurodegeneration and tau-related pathology. Here, we explore the use of non-vertebrate and aquatic vertebrate models to study TBI and neurodegeneration. Drosophila, in particular, provides an opportunity to explore the longitudinal effects of mild rTBI and its impact on endogenous tau, thereby offering valuable insights into the complex interplay between rTBI, tauopathy, and neurodegeneration. These models provide a platform for mechanistic studies and therapeutic interventions, ultimately advancing our understanding of the long-term consequences associated with rTBI and potential avenues for intervention.

Inducing different severities of traumatic brain injury in Drosophila using a piezoelectric actuator

Drosophila models have been instrumental in providing insights into molecular mechanisms of neurodegeneration, with wide application to human disease. The brain degeneration associated with traumatic brain injury (TBI) has been modeled in Drosophila using devices that inflict trauma on multiple parts of the fly body, including the head. However, the injuries produced by these models are not specific in location and are inconsistent between individual animals. We have recently developed a device that can be used to inflict controlled head injury to flies, resulting in physiological responses that are remarkably similar to those observed in humans with TBI. This protocol describes the construction, calibration and use of the Drosophila TBI (dTBI) device, a platform that employs a piezoelectric actuator to reproducibly deliver a force in order to briefly compress the fly head against a metal surface. The extent of head compression can be controlled through an electrical circuit, allowing the operator to set different levels of injury. The entire device can be assembled and calibrated in under a week. The device components and the necessary electrical tools are readily available and cost ~$800. The dTBI device can be used to harness the power of Drosophila genetics and perform large-scale genetic or pharmacological screens, using a 7-d post-injury survival curve to identify modifiers of injury.

Healthful aging mediated by inhibition of oxidative stress

The progressive increase in lifespan over the past century carries with it some adversity related to the accompanying burden of debilitating diseases prevalent in the older population. This review focuses on oxidative stress as a major mechanism limiting longevity in general, and healthful aging, in particular. Accordingly, the first goal of this review is to discuss the role of oxidative stress in limiting longevity, and compare healthful aging and its mechanisms in different longevity models. Secondly, we discuss common signaling pathways involved in protection against oxidative stress in aging and in the associated diseases of aging, e.g., neurological, cardiovascular and metabolic diseases, and cancer. Much of the literature has focused on murine models of longevity, which will be discussed first, followed by a comparison with human models of longevity and their relationship to oxidative stress protection. Finally, we discuss the extent to which the different longevity models exhibit the healthful aging features through physiological protective mechanisms related to exercise tolerance and increased β-adrenergic signaling and also protection against diabetes and other metabolic diseases, obesity, cancer, neurological diseases, aging-induced cardiomyopathy, cardiac stress and osteoporosis.

Cavitation-induced traumatic cerebral contusion and intracerebral hemorrhage in the rat brain by using an off-the-shelf clinical shockwave device

Traumatic cerebral contusion and intracerebral hemorrhages (ICH) commonly result from traumatic brain injury and are associated with high morbidity and mortality rates. Current animal models require craniotomy and provide less control over injury severity. This study proposes a highly reproducible and controllable traumatic contusion and ICH model using non-invasive extracorporeal shockwaves (ESWs). Rat heads were exposed to ESWs generated by an off-the-shelf clinical device plus intravenous injection of microbubbles to enhance the cavitation effect for non-invasive induction of injury. Results indicate that injury severity can be effectively adjusted by using different ESW parameters. Moreover, the location or depth of injury can be purposefully determined by changing the focus of the concave ESW probe. Traumatic contusion and ICH were confirmed by H&E staining. Interestingly, the numbers of TUNEL-positive cells (apoptotic cell death) peaked one day after ESW exposure, while Iba1-positive cells (reactive microglia) and GFAP-positive cells (astrogliosis) respectively peaked seven and fourteen days after exposure. Cytokine assay showed significantly increased expressions of IL-1β, IL-6, and TNF-α. The extent of brain edema was characterized with magnetic resonance imaging. Conclusively, the proposed non-invasive and highly reproducible preclinical model effectively simulates the mechanism of closed head injury and provides focused traumatic contusion and ICH.

Is radial extracorporeal shock wave therapy combined with a specific rehabilitation program (rESWT + RP) more effective than sham-rESWT + RP for acute hamstring muscle complex injury type 3b in athletes? Study protocol for a prospective, randomized, double-blind, sham-controlled single centre trial

Background

Acute injuries of the hamstring muscle complex (HMC) type 3b (interfascicle/bundle-tear) are frequently observed in various sports disciplines both in elite and recreational sport. The treatment of choice of acute HMC injuries type 3b is a progressive physiotherapeutic exercise programme. Besides this, there is currently only insufficient scientific evidence to support other treatment methods, including local infiltrations and injections of platelet-rich-plasma. Very recently, it was demonstrated that extracorporeal shock wave therapy (ESWT) may accelerate regeneration after acute skeletal muscle injury. The aim of the present study is to test the hypothesis that the combination of radial ESWT (rESWT) and a specific rehabilitation program (RP) is effective and safe in treatment of acute HMC injury type 3b in athletes, and is statistically significantly more effective than the combination of sham-rESWT and RP.

Methods

We will perform a double blind, randomized, sham-controlled clinical trial at the clinic KinEf Kinesiología Deportiva, Ciudad Autónoma de Buenos Aires, Argentina. Forty patients with acute HMC injury type 3b will be randomly allocated to receive either rESWT (nine rESWT sessions; three sessions per week; 2500 radial extracorporeal shock waves (rESWs) per session; energy density depending on what the patient tolerates) or sham-rESWT. In addition, all patients will receive a specific rehabilitation program that will last for 8 weeks. The primary outcome measure will be the individual time (days) necessary to return to play. Secondary outcomes will include the presence or absence of reinjury during a time period of 6 months after inclusion into the study.

Discussion

Because of the lack of adequate treatment options for acute HMC injury type 3b in athletes and particularly the high reinjury rate, we hypothesize that the results of this trial will be of importance and have impact on clinical practice.

Trial registration

ClinicalTrials.gov ID NCT03473899. Registered March 22, 2018.