Significance of Omega-3 Fatty Acids in the Prophylaxis and Treatment after Spinal Cord Injury in Rodent Models

Alleviating Severe Cytoskeletal Destruction of Spinal Motor Neurons: Another Effect of Docosahexaenoic Acid in Spinal Cord Injury

Spinal cord injury (SCI) treatment remains a major challenge. Spinal motor neurons (MNs) are seriously injured in the early stage after SCI, but this has not received sufficient attention. Oxidative stress is known to play a crucial role in SCI pathology. Our studies demonstrated that oxidative stress can cause severe damage to the cytoskeleton of spinal MNs. Docosahexaenoic acid (DHA) has been shown to have beneficial effects on SCI, but the mechanism remains unclear, and no study has investigated the effect of DHA on oxidative stress-induced spinal MN injury. Here, we investigated the effect of DHA on spinal MN injury through in vivo and in vitro experiments, focusing on the cytoskeleton. We found that DHA not only promoted spinal MN survival but, more importantly, alleviated the severe cytoskeletal destruction of these neurons induced by oxidative stress in vitro and in mice with SCI in vivo. In addition, the mechanisms involved were investigated and elucidated. These results not only suggested a beneficial role of DHA in spinal MN cytoskeletal destruction caused by oxidative stress and SCI but also indicated the important role of the spinal MN cytoskeleton in the recovery of motor function after SCI. Our study provides new insights for the formulation of SCI treatment.

Omega-3 Polyunsaturated Fatty Acids Protect Neurological Function After Traumatic Brain Injury by Suppressing Microglial Transformation to the Proinflammatory Phenotype and Activating Exosomal NGF/TrkA Signaling

The transformation of microglia to a pro-inflammatory phenotype at the site of traumatic brain injury (TBI) drives the progression of secondary neurodegeneration and irreversible neurological impairment. Omega-3 polyunsaturated fatty acids (PUFA) have been shown to suppress this phenotype transformation, thereby reducing neuroinflammation following TBI, but the molecular mechanisms are unknown. We found that Omega-3 PUFA suppressed the expression of disintegrin metalloproteinase (ADAM17), the enzyme required to convert tumor necrosis factor-α (TNF-α) to the soluble form, thereby inhibiting the TNF-α/NF-κB pathway both in vitro and in a mouse model of TBI. Omega-3 PUFA also prevented the reactive transformation of microglia and promoted the secretion of microglial exosomes containing nerve growth factor (NGF), activating the neuroprotective NGF/TrkA pathway both in culture and TBI model mice. Moreover, Omega-3 PUFA suppressed the pro-apoptotic NGF/P75NTR pathway at the TBI site and reduced apoptotic neuronal death, brain edema, and disruption of the blood-brain barrier. Finally, Omega-3 PUFA preserved sensory and motor function as assessed by two broad-spectrum test batteries. The beneficial effects of Omega-3 PUFA were blocked by an ADAM17 promotor and by a NGF inhibitor, confirming the pathogenic function of ADAM17 and the central neuroprotective role of NGF. Collectively, these findings provide a strong experimental basis for Omega-3 PUFA as a potential clinical treatment for TBI.

ω-3 Polyunsaturated Fatty Acids Improve the Blood-Brain-Barrier Integrity in Contrast-Induced Blood-Brain-Barrier Injury in Uremic Mice

In patients with chronic kidney disease, the need for examinations using contrast media (CM) increases because of underlying diseases. Although contrast agents can affect brain cells, the blood-brain barrier (BBB) protects against brain-cell damage in vivo. However, uremia can disrupt the BBB, increasing the possibility of contrast-agent-induced brain-cell damage in patients with chronic kidney disease (CKD). ω-3 polyunsaturated fatty acids (PUFAs) have shown protective effects on various neurological disorders, including uremic brain injury. This study examined whether ω-3 PUFAs attenuate damage to the BBB caused by uremia and contrast agents in a uremic mouse model and evaluated its associated mechanisms. C57BL/6 mice (eight weeks old, male) and fat-1 mice (b6 background/eight weeks old, male) were divided into groups according to uremic induction, CM, and ω-3 PUFA administration. Uremia was induced via 24 h ischemia-reperfusion (IR) renal injury. One day after CM treatment, the brain tissue, kidney tissue, and blood were collected. The expression levels of glial fibrillary acidic protein (GFAP), claudin 5, CD31, laminin α4, and laminin α5 increased in ω-3 PUFA + CM-treated uremic mice and the brain of fat-1 + CM-treated uremic mice compared with those in the brains of CM-treated uremic mice. The pro-apoptotic protein expression decreased, whereas the anti-apoptotic proteins increased in ω-3 PUFA + CM-treated uremic mice and fat-1 + CM-treated uremic mice compared with CM-treated uremic mice. In addition, the brain-expression levels of p-JNK, p-P53, and p-P38 decreased in the ω-3 PUFA + CM-treated uremic mice and fat-1 + CM-treated uremic mice compared with those in wild-type uremic mice. Our results confirm that uremic toxin and CM damage the BBB and cause brain-cell death. ω-3 PUFAs play a role in BBB protection caused by CM in uremic mice.

The potential effects of polyunsaturated ω-3 fatty acids on spinal cord injury: A systematic review & meta-analysis of preclinical evidence

Polyunsaturated fatty acids (PUFAs) have received attention for their anti-inflammatory and antioxidant properties. Preclinical studies have investigated the efficacy of PUFAs in animal models of spinal cord injury (SCI) to determine if these properties can translate to neuroprotection and locomotor recovery. Findings from such studies have been promising, suggesting PUFAs as potential treatments against the neurological dysfunction induced by SCI. This systematic review and meta-analysis sought to investigate the efficacy of PUFAs for promoting locomotor recovery in animal models of SCI. PubMed, Web of Science and Embase (Ovid) were searched for relevant papers and those that examined the restorative effects of PUFAs on locomotor recovery in preclinical SCI models were included in our analysis. A random effects meta-analysis (restricted maximum likelihood estimator) was employed. A total of 28 studies were included and the results showed the claim that PUFAs have a beneficial therapeutic effect for promoting locomotor recovery (SMD = 1.037, 95% CI = 0.809-1.2644, p = <0.001) and cell survival (SMD = 1.101, 95% CI = 0.889-1.313, p = <0.001) in animal models of SCI. No significant differences for the secondary outcomes of neuropathic pain and lesion volume. Moderate asymmetry was observed in the funnel plots for locomotor recovery, cell survival and neuropathic pain measures, suggesting publication bias. Trim-and-fill analysis estimated 13, 3, 0 and 4 missing studies for locomotor recovery, cell survival, neuropathic pain, and lesion volume, respectively. A modified CAMARADES checklist was also used to assess risk of bias, showing that the median score for all included papers was 4 out of a possible 7.

Pathophysiology and Therapeutic Approaches for Spinal Cord Injury

Spinal cord injury (SCI) is a disabling condition that disrupts motor, sensory, and autonomic functions. Despite extensive research in the last decades, SCI continues to be a global health priority affecting thousands of individuals every year. The lack of effective therapeutic strategies for patients with SCI reflects its complex pathophysiology that leads to the point of no return in its function repair and regeneration capacity. Recently, however, several studies started to uncover the intricate network of mechanisms involved in SCI leading to the development of new therapeutic approaches. In this work, we present a detailed description of the physiology and anatomy of the spinal cord and the pathophysiology of SCI. Additionally, we provide an overview of different molecular strategies that demonstrate promising potential in the modulation of the secondary injury events that promote neuroprotection or neuroregeneration. We also briefly discuss other emerging therapies, including cell-based therapies, biomaterials, and epidural electric stimulation. A successful therapy might target different pathologic events to control the progression of secondary damage of SCI and promote regeneration leading to functional recovery.

Spinal Vascular Shunts: Single-Center Series and Review of the Literature of Their Classification

Spinal arteriovenous shunts (sAVSs) are an uncommon disease, constituting 3 to 4% of intradural lesions; 70% of these lesions are spinal arteriovenous fistulas (sAVFs), whereas spinal arteriovenous malformations (sAVMs) are rarer. Both share the problem of their classification due to the heterogeneity of their angioarchitecture. The aim of this study is to report a series of sAVSs treated in the neurosurgery department of the Hospital Nacional Guillermo Almenara during the 2018–2020 period and to present an overview of the current literature on sAVS classification. We reviewed all medical records of patients diagnosed with sAVFs and sAVMs during the 2018–2020 period, and then we analyzed images with Horos v4.0.0, illustrated some cases with Clip Studio Paint v1.10.5, and performed a descriptive statistical analysis with SPSS v25. Twelve patients were included in this study, eight of which were women (67%) and four of which were men (33%); the age range was from 3 to 74 years. Eight sAVSs were sAVFs, whereas four were sAVMs. The most frequent clinical manifestation was chronic myelopathy in seven patients (58%). Of those treated only by embolization, seven (70%) resulted in complete occlusion (five sAVFs and two sAVMs), while three (30%) remained with a residual lesion. At last follow-up, five patients (42%) improved clinically, and the seven remaining (58%) maintained the same neurological state. sAVSs require a detailed study of their angioarchitecture for proper management. The endovascular treatment is safe with acceptable cure rates. The surgical option should not be set aside.

Bioactive compounds for neuropathic pain: An update on preclinical studies and future perspectives

Among different types of chronic pain, neuropathic pain (NP), arising from damage to the nervous system, including peripheral fibers and central neurons, is notoriously difficult to treat and affects 7-10% of the general population. Currently available treatment options for NP are limited and opioid analgesics have severe side effects and can result in opioid use disorder. Recent studies have exhibited the role of dietary bioactive compounds in the mitigation of NP. Here, we assessed the effects of commonly consumed bioactive compounds (ginger, curcumin, omega-3 polyunsaturated fatty acids, epigallocatechin gallate, resveratrol, soy isoflavones, lycopene, and naringin) on NP and NP-related neuroinflammation. Cellular studies demonstrated that these bioactive compounds reduce inflammation via suppression of NF-κB and MAPK signaling pathways that regulate apoptosis/cell survival, antioxidant, and anti-inflammatory responses. Animal studies strongly suggest that these regularly consumed bioactive compounds have a pronounced anti-NP effect as shown by decreased mechanical allodynia, mechanical hyperalgesia, thermal hyperalgesia, and cold hyperalgesia. The proposed molecular mechanisms include (1) the enhancement of neuron survival, (2) the reduction of neuronal hyperexcitability by activation of antinociceptive cannabinoid 1 receptors and opioid receptors, (3) the suppression of sodium channel current, and (4) enhancing a potassium outward current in NP-affected animals, triggering a cascade of chemical changes within, and between neurons for pain relief. Human studies administered in this area have been limited. Future randomized controlled trials are warranted to confirm the findings of preclinical efficacies using bioactive compounds in patients with NP.

Reduced Muscle Activity of the Upper Extremity in Individuals with Spinal Cord Injuries

Compromised physical ability due to musculoskeletal impairment among spinal cord injury (SCI) patients is known to negatively affect their quality of life. It is essential to comprehensively understand the muscle strength of the upper extremity among patients with SCI to enhance muscle function and capacity to engage in an active lifestyle. The objective of this study was to evaluate the muscle strength of 15 upper extremity muscles among patients with SCI and compare the relative weakness of individual muscles to the control group. Seven male patients with SCI with ASIA impairment scale D and E and 33 males in the control group participated in this study. Each participant performed maximal voluntary contraction of individual muscles, and the electromyography data were recorded. The results showed that the majority of the upper extremity muscles (12 out of 15) showed considerable weakness (24 to 53%) relative to the control group. Furthermore, the relative strength (ranking) of individual muscles among 15 upper extremity muscles was different between patients with SCI and the control group. This information would be useful to the selective strengthening of specific muscles as an intensive rehabilitation effort and prevent overuse and adverse injuries due to excessive muscle training.

Mechanism Underlying Acupuncture Therapy in Spinal Cord Injury: A Narrative Overview of Preclinical Studies

Spinal cord injury (SCI) results from various pathogenic factors that destroy the normal structure and function of the spinal cord, subsequently causing sensory, motor, and autonomic nerve dysfunction. SCI is one of the most common causes of disability and death globally. It leads to severe physical and mental injury to patients and causes a substantial economic burden on families and the society. The pathological changes and underlying mechanisms within SCI involve oxidative stress, apoptosis, inflammation, etc. As a traditional therapy, acupuncture has a positive effect promoting the recovery of SCI. Acupuncture-induced neuroprotection includes several mechanisms such as reducing oxidative stress, inhibiting the inflammatory response and neuronal apoptosis, alleviating glial scar formation, promoting neural stem cell differentiation, and improving microcirculation within the injured area. Therefore, the recent studies exploring the mechanism of acupuncture therapy in SCI will help provide a theoretical basis for applying acupuncture and seeking a better treatment target and acupuncture approach for SCI patients.

Association between Spinal Cord Injury and Alcohol Dependence: A Population-Based Retrospective Cohort Study

Spinal cord injury (SCI) is a devastating disorder. Alcohol abuse has been recognized as hindering SCI patients from rehabilitation, thus leading to longer length of days and poorer prognosis. This article aimed to investigate the association between spinal cord injury (SCI) and alcohol dependence. Data were derived from the National Health Insurance Research Database (NHIRD). The incidence of alcohol dependence between SCI and non-SCI groups was compared. Other possible risk factors were also analyzed. Patients (N = 5670) with SCI from 2000 to 2009 were initially assessed for eligibility. After propensity score matching, 5639 first-time SCI survivors were included. The Cox proportional hazard regression model was used to assess differences in the incidence of alcohol dependence syndrome. Based on the adjusted hazard ratios (HR), the SCI group had a higher hazard for alcohol dependence syndrome compared to the non-SCI group (adjusted HR: 1.39, 95% CI: 1.03~1.86, p = 0.0305). The injury level did not have an impact on the incidence of alcohol dependence syndrome. A higher incidence of alcohol dependence syndrome was related to male patients, lower insurance levels, higher Deyo’s CCI, and psychiatric OPD times. A lower incidence of alcohol dependence syndrome was related to elder age. The incidence of alcohol dependence increased after the occurrence of SCI and was also related to age, sex, monthly income, comorbidities, and psychiatric problems. The injury level did not affect the incidence of alcohol dependence after SCI.

The interplay between oxidative stress and autophagy: focus on the development of neurological diseases

Regarding the epidemiological studies, neurological dysfunctions caused by cerebral ischemia or neurodegenerative diseases (NDDs) have been considered a pointed matter. Mount-up shreds of evidence support that both autophagy and reactive oxygen species (ROS) are involved in the commencement and progression of neurological diseases. Remarkably, oxidative stress prompted by an increase of ROS threatens cerebral integrity and improves the severity of other pathogenic agents such as mitochondrial damage in neuronal disturbances. Autophagy is anticipated as a cellular defending mode to combat cytotoxic substances and damage. The recent document proposes that the interrelation of autophagy and ROS creates a crucial function in controlling neuronal homeostasis. This review aims to overview the cross-talk among autophagy and oxidative stress and its molecular mechanisms in various neurological diseases to prepare new perceptions into a new treatment for neurological disorders. Furthermore, natural/synthetic agents entailed in modulation/regulation of this ambitious cross-talk are described.

Inflammation and Barrier Function Deficits in the Bladder Urothelium of Patients with Chronic Spinal Cord Injury and Recurrent Urinary Tract Infections

Patients with spinal cord injury (SCI) commonly experience neurogenic voiding dysfunctions and urinary tract complications, including recurrent urinary tract infections (rUTI). The bladder mucosa barrier function contributes to UTI prevention. This study investigated changes in bladder urothelium protein expression in patients with SCI and rUTI. From June 2011 to November 2017, 23 patients (19 men and 4 women) with chronic SCI were enrolled (mean age: 43 years. Bladder tissues from 6 healthy adults served as the normal control group. Biopsy samples (9 partial cystectomies and 14 bladder biopsies) were analyzed for functional biomarkers using western blot and immunohistochemistry analysis. The barrier function proteins E-cadherin, zonula occludens 1 (ZO-1) and uroplakin III (UPK-3) were significantly reduced, whereas tumor protein p63 (TP63) was significantly increased in SCI patients compared with controls. No significant differences in basal cell progenitor proteins were observed between groups. The proliferation marker Ki-67, the proapoptotic marker BCL-2-associated X protein (BAX), and proinflammatory proteins were increased in patients with SCI compared with controls. No significant differences were observed between SCI patients with and without recently rUTI. These results suggest that SCI patients experience chronic bladder inflammation, increased apoptosis, and reduced barrier function, contributing to rUTI.

Rethinking the Body in the Brain after Spinal Cord Injury

Spinal cord injuries (SCI) are disruptive neurological events that severly affect the body leading to the interruption of sensorimotor and autonomic pathways. Recent research highlighted SCI-related alterations extend beyond than the expected network, involving most of the central nervous system and goes far beyond primary sensorimotor cortices. The present perspective offers an alternative, useful way to interpret conflicting findings by focusing on the deafferented and deefferented body as the central object of interest. After an introduction to the main processes involved in reorganization according to SCI, we will focus separately on the body regions of the head, upper limbs, and lower limbs in complete, incomplete, and deafferent SCI participants. On one hand, the imprinting of the body’s spatial organization is entrenched in the brain such that its representation likely lasts for the entire lifetime of patients, independent of the severity of the SCI. However, neural activity is extremely adaptable, even over short time scales, and is modulated by changing conditions or different compensative strategies. Therefore, a better understanding of both aspects is an invaluable clinical resource for rehabilitation and the successful use of modern robotic technologies.

Neuroprotective Role of Hypothermia in Acute Spinal Cord Injury

Even nowadays, the question of whether hypothermia can genuinely be considered therapeutic care for patients with traumatic spinal cord injury (SCI) remains unanswered. Although the mechanisms of hypothermia action are yet to be fully explored, early hypothermia for patients suffering from acute SCI has already been implemented in clinical settings. This article discusses measures for inducing various forms of hypothermia and summarizes several hypotheses describing the likelihood of hypothermia mechanisms of action. We present our objective neuro-electrophysiological results and demonstrate that early hypothermia manifests neuroprotective effects mainly during the first- and second-month post-SCI, depending on the severity of the injury, time of intervening, duration, degree, and modality of inducing hypothermia. Nevertheless, eventually, its beneficial effects gradually but consistently diminish. In addition, we report potential complications and side effects for the administration of general hypothermia with a unique referment to the local hypothermia. We also provide evidence that instead of considering early hypothermia post-SCI a therapeutic approach, it is more a neuroprotective strategy in acute and sub-acute phases of SCI that mostly delay, but not entirely avoid, the natural history of the pathophysiological events. Indeed, the most crucial rationale for inducing early hypothermia is to halt these devastating inflammatory and apoptotic events as early and as much as possible. This, in turn, creates a larger time-window of opportunity for physicians to formulate and administer a well-designed personalized treatment for patients suffering from acute traumatic SCI.

Glial-Neuronal Interactions in Pathogenesis and Treatment of Spinal Cord Injury

Traumatic spinal cord injury (SCI) elicits an acute inflammatory response which comprises numerous cell populations. It is driven by the immediate response of macrophages and microglia, which triggers activation of genes responsible for the dysregulated microenvironment within the lesion site and in the spinal cord parenchyma immediately adjacent to the lesion. Recently published data indicate that microglia induces astrocyte activation and determines the fate of astrocytes. Conversely, astrocytes have the potency to trigger microglial activation and control their cellular functions. Here we review current information about the release of diverse signaling molecules (pro-inflammatory vs. anti-inflammatory) in individual cell phenotypes (microglia, astrocytes, blood inflammatory cells) in acute and subacute SCI stages, and how they contribute to delayed neuronal death in the surrounding spinal cord tissue which is spared and functional but reactive. In addition, temporal correlation in progressive degeneration of neurons and astrocytes and their functional interactions after SCI are discussed. Finally, the review highlights the time-dependent transformation of reactive microglia and astrocytes into their neuroprotective phenotypes (M2a, M2c and A2) which are crucial for spontaneous post-SCI locomotor recovery. We also provide suggestions on how to modulate the inflammation and discuss key therapeutic approaches leading to better functional outcome after SCI.

Oral Capsaicinoid Administration Alters the Plasma Endocannabinoidome and Fecal Microbiota of Reproductive-Aged Women Living with Overweight and Obesity

Capsaicinoids, the pungent principles of chili peppers and prototypical activators of the transient receptor potential of the vanilloid type-1 (TRPV1) channel, which is a member of the expanded endocannabinoid system known as the endocannabinoidome (eCBome), counteract food intake and obesity. In this exploratory study, we examined the blood and stools from a subset of the participants in a cohort of reproductive-aged women with overweight/obesity who underwent a 12-week caloric restriction of 500 kcal/day with the administration of capsaicinoids (two capsules containing 100 mg of a capsicum annuum extract (CAE) each for a daily dose of 4 mg of capsaicinoids) or a placebo. Samples were collected immediately before and after the intervention, and plasma eCBome mediator levels (from 23 participants in total, 13 placebo and 10 CAE) and fecal microbiota taxa (from 15 participants in total, 9 placebo and 6 CAE) were profiled using LC-MS/MS and 16S metagenomic sequencing, respectively. CAE prevented the reduced caloric-intake-induced decrease in beneficial eCBome mediators, i.e., the TRPV1, GPR119 and/or PPARα agonists, N-oleoyl-ethanolamine, N-linoleoyl-ethanolamine and 2-oleoyl-glycerol, as well as the anti-inflammatory N-acyl-ethanolamines N-docosapentaenyl-ethanolamine and N-docosahexaenoyl-ethanolamine. CAE produced few but important alterations in the fecal microbiota, such as an increased relative abundance of the genus Flavonifractor, which is known to be inversely associated with obesity. Correlations between eCBome mediators and other potentially beneficial taxa were also observed, thus reinforcing the hypothesis of the existence of a link between the eCBome and the gut microbiome in obesity.