The Interplay between Ferroptosis and Neuroinflammation in Central Neurological Disorders.

Central neurological disorders are significant contributors to morbidity, mortality, and long-term disability globally in modern society. These encompass neurodegenerative diseases, ischemic brain diseases, traumatic brain injury, epilepsy, depression, and more. The involved pathogenesis is notably intricate and diverse. Ferroptosis and neuroinflammation play pivotal roles in elucidating the causes of cognitive impairment stemming from these diseases. Given the concurrent occurrence of ferroptosis and neuroinflammation due to metabolic shifts such as iron and ROS, as well as their critical roles in central nervous disorders, the investigation into the co-regulatory mechanism of ferroptosis and neuroinflammation has emerged as a prominent area of research. This paper delves into the mechanisms of ferroptosis and neuroinflammation in central nervous disorders, along with their interrelationship. It specifically emphasizes the core molecules within the shared pathways governing ferroptosis and neuroinflammation, including SIRT1, Nrf2, NF-κB, Cox-2, iNOS/NO·, and how different immune cells and structures contribute to cognitive dysfunction through these mechanisms. Researchers' findings suggest that ferroptosis and neuroinflammation mutually promote each other and may represent key factors in the progression of central neurological disorders. A deeper comprehension of the common pathway between cellular ferroptosis and neuroinflammation holds promise for improving symptoms and prognosis related to central neurological disorders.

Emerging functions and therapeutic targets of IL-38 in central nervous system diseases.

Interleukin (IL)-38 is a newly discovered cytokine of the IL-1 family, which binds various receptors (i.e., IL-36R, IL-1 receptor accessory protein-like 1, and IL-1R1) in the central nervous system (CNS). The hallmark physiological function of IL-38 is competitive binding to IL-36R, as does the IL-36R antagonist. Emerging research has shown that IL-38 is abnormally expressed in the serum and brain tissue of patients with ischemic stroke (IS) and autism spectrum disorder (ASD), suggesting that IL-38 may play an important role in neurological diseases. Important advances include that IL-38 alleviates neuromyelitis optica disorder (NMOD) by inhibiting Th17 expression, improves IS by protecting against atherosclerosis via regulating immune cells and inflammation, and reduces IL-1ß and CXCL8 release through inhibiting human microglial activity post-ASD. In contrast, IL-38 mRNA is markedly increased and is mainly expressed in phagocytes in spinal cord injury (SCI). IL-38 ablation attenuated SCI by reducing immune cell infiltration. However, the effect and underlying mechanism of IL-38 in CNS diseases remain inadequately characterized. In this review, we summarize the biological characteristics, pathophysiological role, and potential mechanisms of IL-38 in CNS diseases (e.g., NMOD, Alzheimer's disease, ASD, IS, TBI, and SCI), aiming to explore the therapeutic potential of IL-38 in the prevention and treatment of CNS diseases.

The MT1 receptor as the target of ramelteon neuroprotection in ischemic stroke.

Stroke is the leading cause of death and disability worldwide. Novel and effective therapies for ischemic stroke are urgently needed. Here, we report that melatonin receptor 1A (MT1) agonist ramelteon is a neuroprotective drug candidate as demonstrated by comprehensive experimental models of ischemic stroke, including a middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia in vivo, organotypic hippocampal slice cultures ex vivo, and cultured neurons in vitro; the neuroprotective effects of ramelteon are diminished in MT1-knockout (KO) mice and MT1-KO cultured neurons. For the first time, we report that the MT1 receptor is significantly depleted in the brain of MCAO mice, and ramelteon treatment significantly recovers the brain MT1 losses in MCAO mice, which is further explained by the Connectivity Map L1000 bioinformatic analysis that shows gene-expression signatures of MCAO mice are negatively connected to melatonin receptor agonist like Ramelteon. We demonstrate that ramelteon improves the cerebral blood flow signals in ischemic stroke that is potentially mediated, at least, partly by mechanisms of activating endothelial nitric oxide synthase. Our results also show that the neuroprotection of ramelteon counteracts reactive oxygen species-induced oxidative stress and activates the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. Ramelteon inhibits the mitochondrial and autophagic death pathways in MCAO mice and cultured neurons, consistent with gene set enrichment analysis from a bioinformatics perspective angle. Our data suggest that Ramelteon is a potential neuroprotective drug candidate, and MT1 is the neuroprotective target for ischemic stroke, which provides new insights into stroke therapy. MT1-KO mice and cultured neurons may provide animal and cellular models of accelerated ischemic damage and neuronal cell death.

ACSL4-Mediated Ferroptosis and Its Potential Role in Central Nervous System Diseases and Injuries.

As an iron-dependent regulated form of cell death, ferroptosis is characterized by iron-dependent lipid peroxidation and has been implicated in the occurrence and development of various diseases, including nervous system diseases and injuries. Ferroptosis has become a potential target for intervention in these diseases or injuries in relevant preclinical models. As a member of the Acyl-CoA synthetase long-chain family (ACSLs) that can convert saturated and unsaturated fatty acids, Acyl-CoA synthetase long-chain familymember4 (ACSL4) is involved in the regulation of arachidonic acid and eicosapentaenoic acid, thus leading to ferroptosis. The underlying molecular mechanisms of ACSL4-mediated ferroptosis will promote additional treatment strategies for these diseases or injury conditions. Our review article provides a current view of ACSL4-mediated ferroptosis, mainly including the structure and function of ACSL4, as well as the role of ACSL4 in ferroptosis. We also summarize the latest research progress of ACSL4-mediated ferroptosis in central nervous system injuries and diseases, further proving that ACSL4-medicated ferroptosis is an important target for intervention in these diseases or injuries.

Molecular Toxicology and Pathophysiology of Comorbid Alcohol Use Disorder and Post-Traumatic Stress Disorder Associated with Traumatic Brain Injury.

The increasing comorbidity of alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD) associated with traumatic brain injury (TBI) is a serious medical, economic, and social issue. However, the molecular toxicology and pathophysiological mechanisms of comorbid AUD and PTSD are not well understood and the identification of the comorbidity state markers is significantly challenging. This review summarizes the main characteristics of comorbidity between AUD and PTSD (AUD/PTSD) and highlights the significance of a comprehensive understanding of the molecular toxicology and pathophysiological mechanisms of AUD/PTSD, particularly following TBI, with a focus on the role of metabolomics, inflammation, neuroendocrine, signal transduction pathways, and genetic regulation. Instead of a separate disease state, a comprehensive examination of comorbid AUD and PTSD is emphasized by considering additive and synergistic interactions between the two diseases. Finally, we propose several hypotheses of molecular mechanisms for AUD/PTSD and discuss potential future research directions that may provide new insights and translational application opportunities.

Extended characterization of IL-33/ST2 as a predictor for wound age determination in skin wound tissue samples of humans and mice.

Interleukin (IL)-33, an important inflammatory cytokine, is highly expressed in skin wound tissue and serum of humans and mice, and plays an essential role in the process of skin wound healing (SWH) dependent on the IL-33/suppression of tumorigenicity 2 (ST2) pathway. However, whether IL-33 and ST2 themselves, as well as their interaction, can be applied for skin wound age determination in forensic practice remains incompletely characterized. Human skin samples with injured intervals of a few minutes to 24 hours (hs) and mouse skin samples with injured intervals of 1 h to 14 days (ds) were collected. Herein, the results demonstrated that IL-33 and ST2 are increased in the human skin wounds, and that in mice skin wounds, there is an increase over time, with IL-33 expression peaking at 24 hs and 10 ds, and ST2 expression peaking at 12 hs and 7 ds. Notably, the relative quantity of IL-33 and ST2 proteins < 0.35 suggested a wound age of 3 hs; their relative quantity > 1.0 suggested a wound age of 24 hs post-mouse skin wounds. In addition, immunofluorescent staining results showed that IL-33 and ST2 were consistently expressed in the cytoplasm of F4/80-positive macrophages and CD31-positive vascular endothelial cells with or without skin wounds, whereas nuclear localization of IL-33 was absent in α-SMA-positive myofibroblasts with skin wounds. Interestingly, IL-33 administration facilitated the wound area closure by increasing the proliferation of cytokeratin (K) 14 -positive keratinocytes and vimentin-positive fibroblasts. In contrast, treating with its antagonist (i.e., anti-IL-33) or receptor antagonist (e.g., anti-ST2) exacerbated the aforementioned pathological changes. Moreover, treatment with IL-33 combined with anti-IL-33 or anti-ST2 reversed the effect of IL-33 on facilitating skin wound closure, suggesting that IL-33 administration facilitated skin wound closure through the IL-33/ST2 signaling pathway. Collectively, these findings indicate that the detection of IL-33/ST2 might be a reliable biomarker for the determination of skin wound age in forensic practice.

Ruxolitinib, a promising therapeutic candidate for traumatic brain injury through maintaining the homeostasis of cathepsin B.

Traumatic brain injury (TBI) is one of the main causes of death and disability in the world. Owing to the heterogeneity and complexity of TBI pathogenesis, there is still no specific drug. Our previous studies have proved the neuroprotective effect of Ruxolitinib (Ruxo) on TBI, but further are needed to explore the potent mechanisms and potential translational application. Compelling evidence indicates that Cathepsin B (CTSB) plays an important role in TBI. However, the relationships between Ruxo and CTSB upon TBI remain non-elucidated. In this study, we established a mouse model of moderate TBI to clarify it. The neurological deficit in the behavioral test was alleviated when Ruxo administrated at 6 h post-TBI. Additionally, Ruxo significantly reduced the lesion volume. As for the pathological process of acute phase, Ruxo remarkably reduced the expression of proteins associated with cell demise, neuroinflammation, and neurodegeneration. Then the expression and location of CTSB were detected respectively. We found that the expression of CTSB exhibits a transient decrease and then persistent increase following TBI. The distribution of CTSB, mainly located at NeuN-positive neurons was unchanged. Importantly, the dysregulation of CTSB expression was reversed with the treatment of Ruxo. The timepoint was chosen when CTSB decreased, to further analyze its change in the extracted organelles; and Ruxo maintained the homeostasis of it in sub-cellular. In summary, our results demonstrate that Ruxo plays neuroprotection through maintaining the homeostasis of CTSB, and will be a promising therapeutic candidate for TBI in clinic.

Melatonin ameliorates neurological deficits through MT2/IL-33/ferritin H signaling-mediated inhibition of neuroinflammation and ferroptosis after traumatic brain injury.

Although traumatic brain injury (TBI) is a common cause of death and disability worldwide, there is currently a lack of effective therapeutic drugs and targets. To reveal the complex pathophysiologic mechanisms of TBI, we performed transcriptome analysis of the mouse cerebral cortex and immunohistochemical analysis of human cerebral tissues. The genes Mt1, Mt2, Il33, and Fth1 were upregulated post-TBI and enriched in pathways associated with the inflammatory response, oxidative phosphorylation, and ferroptosis. As an agonist of MT1/2, melatonin (MLT) confers anti-oxidant, anti-inflammatory, and anti-ferroptosis effects after TBI. However, whether these upregulated genes and their corresponding pathways are involved in the neuroprotective effect of MLT remains unclear. In this study, interventions to inhibit MT1/2, IL-33, and ferroptosis (i.e., ferritin H (Fth)-KO) were applied post-TBI. The results showed that MLT attenuated TBI-induced cerebral edema and neurological outcomes by inhibiting inflammation and ferroptosis. Mechanistically, MLT mainly suppressed inflammatory responses and ferroptosis via the activation of MT2 and IL-33 pathways. Building on the previous finding that Fth deletion increases susceptibility to ferroptosis post-TBI, we demonstrated that Fth depletion remarkably exacerbated the post-TBI inflammatory response, and abolished the anti-inflammatory effects of MLT both in vivo and in vitro. Furthermore, the post-TBI anti-inflammatory effect of MLT, which occurs by promoting the polarization of CD206+ macrophages, was dependent on Fth. Taken together, these results clarified that MLT alleviates inflammation- and ferroptosis-mediated brain edema and neurological deficits by activating the MT2/IL-33/Fth pathway, which provides a novel target and theoretical basis for MLT to treat TBI patients.

TrkB agonist N-acetyl serotonin promotes functional recovery after traumatic brain injury by suppressing ferroptosis via the PI3K/Akt/Nrf2/Ferritin H pathway.

Ferroptosis is a form of regulated cell death that is mainly triggered by iron-dependent lipid peroxidation. A growing body of evidence suggests that ferroptosis is involved in the pathophysiology of traumatic brain injury (TBI), and tropomyosin-related kinase B (TrkB) deficiency would mediate TBI pathologies. As an agonist of TrkB and an immediate precursor of melatonin, N-acetyl serotonin (NAS) exerts several beneficial effects on TBI, but there is no information regarding the role of NAS in ferroptosis after TBI. Here, we examined the effect of NAS treatment on TBI-induced functional outcomes and ferroptosis. Remarkably, the administration of NAS alleviated TBI-induced neurobehavioral deficits, lesion volume, and neurodegeneration. NAS also rescued TBI-induced mitochondrial shrinkage, the changes in ferroptosis-related molecule expression, and iron accumulation in the ipsilateral cortex. Similar results were obtained with a well-established ferroptosis inhibitor, liproxstatin-1. Furthermore, NAS activated the TrkB/PI3K/Akt/Nrf2 pathway in the mouse model of TBI, while inhibition of PI3K and Nrf2 weakened the protection of NAS against ferroptosis both in vitro and in vivo, suggesting that a possible pathway linking NAS to the action of anti-ferroptosis was TrkB/PI3K/Akt/Nrf2. Given that ferritin H (Fth) is a known transcription target of Nrf2, we then investigated the effects of NAS on neuron-specific Fth knockout (Fth-KO) mice. Strikingly, Fth deletion almost abolished the protective effects of NAS against TBI-induced ferroptosis and synaptic damage, although Fth deletion-induced susceptibility toward ferroptosis after TBI was reversed by an iron chelator, deferoxamine. Taken together, these data indicate that the TrkB agonist NAS treatment appears to improve brain function after TBI by suppressing ferroptosis, at least in part, through activation of the PI3K/Akt/Nrf2/Fth pathway, providing evidence that NAS is likely to be a promising anti-ferroptosis agent for further treatment for TBI.

Brain-specific loss of Abcg1 disturbs cholesterol metabolism and aggravates pyroptosis and neurological deficits after traumatic brain injury.

Based on accumulating evidence, cholesterol metabolism dysfunction has been suggested to contribute to the pathophysiological process of traumatic brain injury (TBI) and lead to neurological deficits. As a key transporter of cholesterol that efflux from cells, the ATP-binding cassette (ABC) transporter family exerts many beneficial effects on central nervous system (CNS) diseases. However, there is no study regarding the effects and mechanisms of ABCG1 on TBI. As expected, TBI resulted in the different time-course changes of cholesterol metabolism-related molecules in the injured cortex. Considering ABCG1 is expressed in neuron and glia post-TBI, we generated nestin-specific Abcg1 knockout (Abcg1-KO) mice using the Cre/loxP recombination system. These Abcg1-KO mice showed reduced plasma high-density lipoprotein cholesterol levels and increased plasma lower-density lipoprotein cholesterol levels under the base condition. After TBI, these Abcg1-KO mice were susceptible to cholesterol metabolism turbulence. Moreover, Abcg1-KO exacerbated TBI-induced pyroptosis, apoptosis, neuronal cell insult, brain edema, neurological deficits, and brain lesion volume. Importantly, we found that treating with retinoid X receptor (RXR, the upstream molecule of ABCG1) agonist, bexarotene, in Abcg1-KO mice partly rescued TBI-induced neuronal damages mentioned above and improved functional deficits versus vehicle-treated group. These data show that, in addition to regulating brain cholesterol metabolism, Abcg1 improves neurological deficits through inhibiting pyroptosis, apoptosis, neuronal cell insult, and brain edema. Moreover, our findings demonstrate that the cerebroprotection of Abcg1 on TBI partly relies on the activation of the RXRalpha/PPARgamma pathway, which provides a potential therapeutic target for treating TBI.

Emerging Effects of IL-33 on COVID-19.

Since the start of COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more than 6 million people have lost their lives worldwide directly or indirectly. Despite intensified efforts to clarify the immunopathology of COVID-19, the key factors and processes that trigger an inflammatory storm and lead to severe clinical outcomes in patients remain unclear. As an inflammatory storm factor, IL-33 is an alarmin cytokine, which plays an important role in cell damage or infection. Recent studies have shown that serum IL-33 is upregulated in COVID-19 patients and is strongly associated with poor outcomes. Increased IL-33 levels in severe infections may result from an inflammatory storm caused by strong interactions between activated immune cells. However, the effects of IL-33 in COVID-19 and the underlying mechanisms remain to be fully elucidated. In this review, we systematically discuss the biological properties of IL-33 under pathophysiological conditions and its regulation of immune cells, including neutrophils, innate lymphocytes (ILCs), dendritic cells, macrophages, CD4+ T cells, Th17/Treg cells, and CD8+ T cells, in COVID-19 phagocytosis. The aim of this review is to explore the potential value of the IL-33/immune cell pathway as a new target for early diagnosis, monitoring of severe cases, and clinical treatment of COVID-19.

Targeting Molecular Mediators of Ferroptosis and Oxidative Stress for Neurological Disorders.

With the acceleration of population aging, nervous system diseases including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), anxiety, depression, stroke, and traumatic brain injury (TBI) have become a huge burden on families and society. The mechanism of neurological disorders is complex, which also lacks effective treatment, so relevant research is required to solve these problems urgently. Given that oxidative stress-induced lipid peroxidation eventually leads to ferroptosis, both oxidative stress and ferroptosis are important mechanisms causing neurological disorders, targeting mediators of oxidative stress and ferroptosis have become a hot research direction at present. Our review provides a current view of the mechanisms underlying ferroptosis and oxidative stress participate in neurological disorders, the potential application of molecular mediators targeting ferroptosis and oxidative stress in neurological disorders. The target of molecular mediators or agents of oxidative stress and ferroptosis associated with neurological disorders, such as reactive oxygen species (ROS), nuclear factor erythroid 2-related factor-antioxidant response element (Nrf2-ARE), n-acetylcysteine (NAC), Fe2+, NADPH, and its oxidases NOX, has been described in this article. Given that oxidative stress-induced ferroptosis plays a pivotal role in neurological disorders, further research on the mechanisms of ferroptosis caused by oxidative stress will help provide new targets for the treatment of neurological disorders.

Targeting iNOS Alleviates Early Brain Injury After Experimental Subarachnoid Hemorrhage via Promoting Ferroptosis of M1 Microglia and Reducing Neuroinflammation.

Numerous studies have demonstrated the role of neuroinflammation in mediating acute pathophysiological events of early brain injury after subarachnoid hemorrhage (SAH). However, it is not clear how to target this inflammatory cascade after SAH. M1 activation of microglia is an important pathological mechanism driving neuroinflammation in SAH, which is considered aggressive, leading to cytotoxicity and robust inflammation related to the release of proinflammatory cytokines and chemokines after SAH. Thus, reducing the number of M1 microglia represents a potential target for therapies to improve outcomes after SAH. Previous studies have found that inducible nitric oxide synthase (iNOS/NO•) plays an essential role in promoting the survival of M1 microglia by blocking ferroptosis. Ferroptosis is a new type of iron-dependent cellular procedural death associated with pathological cell death related to mammalian degenerative diseases, cerebral hemorrhage, and traumatic brain injury. Here, we investigated the effect of L-NIL, an inhibitor of iNOS, on M1 microglia, neuroinflammation, neuronal cell death, brain edema, and neurological function in an experimental SAH model in vivo and in vitro. We found that L-NIL reduced the number of M1 microglia and alleviated neuroinflammation following SAH. Notably, treatment with L-NIL relieves brain edema and neuronal injury and improves outcomes of neurological function after SAH in rats. Mechanistically, we found that L-NIL inhibited the expression of iNOS and promoted ferroptosis of M1 microglia by increasing the expression of ferroptosis-related proteins and lipid peroxidation in an in vitro model of SAH, which was reversed by a ferroptosis inhibitor, liproxstatin-1. In addition, inhibiting iNOS had no significant effect on ferroptosis of neurons after oxyhemoglobin stimulation in vitro. Thus, our research demonstrated that inhibition of iNOS might represent a potential therapeutic strategy to improve outcomes after SAH by promoting ferroptosis of M1 microglia and reducing neuroinflammation.

Interleukin-13 Affects the Recovery Processes in a Mouse Model of Hemorrhagic Stroke with Bilateral Tibial Fracture.

As one form of stroke, intracerebral hemorrhage (ICH) is a fatal cerebrovascular disease, which has high morbidity and mortality and lacks effective medical treatment. Increased infiltration of inflammatory cytokines coupled with pyroptotic cell death is involved in the pathophysiological process of ICH. However, little is known about whether concomitant fracture patients have the same progression of inflammation and pyroptosis. Hence, we respectively established the mouse ICH model and ICH with bilateral tibial fracture model (MI) to explore the potential cross-talk between the above two injuries. We found that MI obviously reversed the expressions of pyroptosis-associated proteins, which were remarkably up-regulated at the acute phase after ICH. Similar results were observed in neuronal expressions via double immunostaining. Furthermore, brain edema was also significantly alleviated in mice who suffered MI, when compared with ICH alone. To better clarify the potential mechanisms that mediated this cross-talk, recombinant mouse interleukin-13 (IL-13) was used to investigate its effect on pyroptosis in the mouse MI model, in which a lower level of IL-13 was observed. Remarkably, IL-13 administration re-awakened cell death, which was mirrored by the re-upregulation of pyroptosis-associated proteins and PI-positive cell counts. The results of hemorrhage volume and behavioral tests further confirmed its critical role in regulating neurological functions. Besides, the IL-13-treated MI group showed poor outcomes of fracture healing. To sum up, our research indicates that controlling the IL-13 content in the acute phase would be a promising target in influencing the outcomes of brain injury and fracture, and meanwhile, provides new evidence in repairing compound injuries in clinics.

Ferristatin II, an Iron Uptake Inhibitor, Exerts Neuroprotection against Traumatic Brain Injury via Suppressing Ferroptosis.

As a specific ferroptosis marker, transferrin receptor 1 (TfR1) expression is increased following traumatic brain injury (TBI), but the precise role of TfR1 in TBI-induced ferroptosis and neurodegeneration remains to be determined. To further identify more potent ferroptosis inhibitors and effective targets for treating TBI, our study aims at investigating the effects of TfR1 on ferroptosis in a mouse TBI model using ferristatin II (an iron uptake and TfR1 inhibitor). The effect of ferristatin II was first verified in the HT-22 cell line in vitro and showed antiferroptotic action when exposed to ferric citrate (FAC), which is in parallel with the results obtained from the positive controls, including deferoxamine (DFO) and liproxstatin-1 (Lip-1). In vivo, ferristatin II administration reduced the expression of TfR1 at 12 h after TBI, and immunofluorescence experiments further confirmed that this decreased TfR1-positive cells were neurons. Importantly, ferristatin II suppressed TBI-induced iron homeostatic imbalance by decreasing the content of Fe (III) and iron-positive deposits and reversed the expression of iron homeostasis-related proteins. Moreover, ferristatin II attenuated TBI-induced lipid peroxidation by reversing the expression of lipid peroxidative genes and proteins, as well as the increase in malondialdehyde (MDA) level following TBI. Finally, ferristatin II alleviated TBI-induced neuronal injury and neurodegeneration, as detected by staining with Nissl and Fluoro-Jade B, thereby exerting a neuroprotective effect. In summary, these data indicated that ferristatin II might be a potential strategy to restrain ferroptosis and develop novel therapeutic agents against TBI.

Restraint Stress Delays the Recovery of Neurological Impairments and Exacerbates Brain Damages through Activating Endoplasmic Reticulum Stress-mediated Neurodegeneration/Autophagy/Apopotosis post Moderate Traumatic Brain Injury.

Based on accumulating evidence, patients recovering from mild and moderate traumatic brain injury (TBI) often experience increased sensitivity to stressful events. However, few studies have assessed on the effects and pathophysiological mechanisms of stress on TBI. In the current study, using a mouse model of moderate TBI, we investigated whether restraint stress (RS) regulates secondary neurodegeneration and neuronal cell death, which are commonly associated with neurological dysfunctions. Our data showed that RS significantly reduced body weight recovery, delayed the recovery of neurological functions (motor function, cognitive function and anxiety-like behavior) and exacerbated the brain lesion volume after moderate TBI. Immunofluorescence results indicated that moderate TBI-induced cell insults and blood-brain barrier leakage were aggravated by RS. Further Western blotting experiments showed that RS activated endoplasmic reticulum (ER) stress excessively after moderate TBI and decreased the number of NeuN-positive cells, but increased the number of CHOP/NeuN-co-positive cells by performing immunostaining in the injured cortex after moderate TBI. Moreover, RS increased the ratios of CHOP/Aß and CHOP/p-Tau co-positive cells in the injured cortex after moderate TBI. However, blocking ER stress with the classic ER stress inhibitor salubrinal remarkably decreased apoptosis and the levels of autophagy-related proteins in the mouse model of moderate TBI plus RS. Collectively, RS delays the recovery of neurological function and deteriorates morphological damage by excessively activating ER stress-mediated neurodegeneration, apoptosis and autophagy after moderate TBI. Thus, monitoring stress levels in patients recovering from non-severe TBI may merit consideration in the future.

Dynamics of insects, microorganisms and muscle mRNA on pig carcasses and their significances in estimating PMI.

The accurate estimate of the postmortem interval (PMI) is of vital significance in the investigation of homicide cases. In this study, three pig carcasses were placed in the field to study the pattern of insect succession, the change of microorganisms and the degradation of muscle tissue RNA during the decomposition process. The results showed that insects could quickly colonize the carcasses and still exist on them until the end of the experiment (41 days). Their development and succession patterns are useful indicators for PMI estimation. The diversity of rectal microorganisms decreased with the decomposition time. In different decomposition periods, significant differences in the rectal and soil microbial composition and relative abundance were found, which could be used to estimate the PMI with an accuracy of 3-4 days. The RNA of muscle tissue was found to have a time-dependent relationship with the PMI. Ppia and Gapdh showed a linear upward trend within 10 h after the death, followed by a gradual downward trend from 10 to 240 h. The expression of ß-actin gene showed a gradual downward trend during 0-240 h. This is the first study in China to analyze the changes of insects, muscle RNA and microorganisms on pig carcasses in the same natural environment, which provide basic data for the PMI estimation.

Ferroptosis Mediated by Lipid Reactive Oxygen Species: A Possible Causal Link of Neuroinflammation to Neurological Disorders.

Increasing evidence indicates a possible causal link between neuroinflammation and neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and stroke. A putative mechanism underlying such a link can be explained by ferroptosis. Current studies have shown that disturbances of iron homeostasis, glutamate excitatory toxicity, lipid reactive oxygen species (ROS), and other manifestations related to ferroptosis can be detected in several neurological disorders caused by neuroinflammation. To date, compelling evidence indicates that damage-associated molecular pattern (DAMP) molecules (e.g., ROS) produced in the process of ferroptosis activate glial cells by activating neuroimmune pathways and then produce a series of inflammatory factors which contribute to neurological disorders. Our review article provides a current view of the involvement of ferroptosis or ROS in the pathological process of neuroinflammation, the effects of neuroinflammation mediated by ferroptosis in neurological disorders, a better understanding of the mechanisms underlying ferroptosis participates in neuroinflammation, and the potential treatments for neurological disorders. In addition, further research on the mechanisms of ferroptosis as well as the link between ferroptosis and neuroinflammation will help provide new targets for treatment.

Autophagy inhibition facilitates wound closure partially dependent on the YAP/IL-33 signaling in a mouse model of skin wound healing.

Autophagy is a self-phagocytic and highly evolutionarily conserved intracellular lysosomal catabolic system, which plays a vital role in a variety of trauma models, including skin wound healing (SWH). However, the roles and potential mechanisms of autophagy in SWH are still controversial. We firstly investigated the role of autophagy in SWH-induced wound closure rate, inflammatory response, and histopathology, utilizing an inhibitor of autophagy 3-methyladenine (3-MA) and its agonist rapamycin (RAP). As expected, we found 3-MA treatment remarkably increased the wound closure rate, combated inflammation response, and mitigated histopathological changes, while RAP delivery aggravated SWH-induced pathological damage. To further exploit the underlying mechanism of autophagy regulating inflammation, the specific inhibitors of yes-associated protein (YAP), Verteporfin, and Anti-IL-33 were applied. Herein, treating with 3-MA markedly suppressed the expression of tumor necrosis factor-α (TNF-α), IL-1ß, and IL-6, promoted that of IL-10, IL-33, and ST2, while RAP administration reverted SWH-induced the up-regulation of these inflammatory cytokines mentioned above. Importantly, Verteporfin administration not only down-regulated the expression levels of YAP, TNF-α, and IL-6 but also up-regulated that of IL-33 and IL-10. Unexpectedly, 3-MA or RAP retreatment did not have any impact on the changes in IL-33 among these inflammatory indicators. Furthermore, elevated expression of IL-33 promoted wound closure and alleviated the pathological damage, whereas, its antagonist Anti-IL-33 treatment overtly reversed the above-mentioned effects of IL-33. Moreover, 3-MA in combination with anti-IL-33 treatment reversed the role of 3-MA alone in mitigated pathological changes, but they failed to revert the effect of anti-IL-33 alone on worsening pathological damage. In sum, emerging data support the novel contribution of the YAP/IL-33 pathway in autophagy inhibition against SWH-induced pathological damage, and highlight that the autophagy/YAP/IL-33 signal axis is expected to become a new therapeutic target for SWH.

Ruxolitinib exerts neuroprotection via repressing ferroptosis in a mouse model of traumatic brain injury.

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Various forms of cells death are involved in the pathological process of TBI, without exception to ferroptosis, which is mainly triggered by iron-dependent lipid peroxidation. Although there have been studies on ferroptosis and TBI, the effect of ruxolitinib (Ruxo), one type of FDA approved drugs for treating myelofibrosis, on the process of ferroptosis post-TBI is remained non-elucidated. Therefore, using a controlled cortical impact device to establish the mouse TBI model, we examined the effect of Ruxo on TBI-induced ferroptosis, in which the inhibitor of ferroptosis, Ferrostatin-1 (Fer-1) was used as a positive control. Moreover, we also respectively explored the effects of these two interventions on neurological deficits caused by TBI. We firstly examined the expression patterns of ferroptosis-related markers at protein level at different time points after TBI. And based on the expression changes of these markers, we chose 12 h post-TBI to prove the effect of Ruxo on ferroptosis. Importantly, we found the intensely inhibitory effect of Ruxo on ferroptosis, which is in parallel with the results obtained after Fer-1-treatment. In addition, these two treatments both alleviated the content of brain water and degree of neurodegeneration in the acute phase of TBI. Finally, we further confirmed the neuroprotective effect of Ruxo or Fer-1 via the wire-grip test, Morris water maze and open field test, respectively. Thereafter, the lesion volume and iron deposition were also measured to certificate their effects on the long-term outcomes of TBI. Our results ultimately demonstrate that inhibiting ferroptosis exerts neuroprotection, and this is another neuroprotective mechanism of Ruxo on TBI.