Melatonin Treatment Regulates SIRT3 Expression in Early Brain Injury (EBI) Due to Reactive Oxygen Species (ROS) in a Mouse Model of Subarachnoid Hemorrhage (SAH)

Improving anti-oxidant stress treatment of subarachnoid hemorrhage through self-assembled nanoparticles of oleanolic acid

Subarachnoid hemorrhage (SAH) is a life-threatening acute hemorrhagic cerebrovascular disease, with early brain injury (EBI) being the main cause of high mortality and severe neurological dysfunction. Oxidative stress plays a crucial role in the pathogenesis of EBI. In this study, we synthesized antioxidant stress nanoparticles based on self-assembled oleanolic acid (OA) using the solvent volatilization method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) techniques were employed to analyze and understand the self-assembly mechanism of oleic acid nanoparticles (OA NPs). The TUNEL assay, Nissl staining, and brain water content measurements were conducted to investigate the impact of OA NPs on cortical neuronal injury. Additionally, Western blot analysis was performed to investigate the antioxidant stress mechanism of OA NPs. The result showed that OA NPs exhibited a spherical structure with an average diameter of 168 nm. The application of OA NPs in SAH has been found to contribute to the reduction of keap1 protein levels and an increase in the nuclear level of Nrf2. As a result, the transcription of antioxidant stress proteins, including HO1 and NQO1, is triggered. The activation of the antioxidant stress pathway by OA NPs ultimately leads to a decrease in neuron damage and an improvement in neurological dysfunction. In conclusion, we successfully designed and synthesized OA NPs that can efficiently target the site of SAH. These nanoparticles have demonstrated their potential as antioxidants for the treatment of SAH, offering significant clinical applications.

Tat-NR2B9c attenuates oxidative stress via inhibition of PSD95-NR2B-nNOS complex after subarachnoid hemorrhage in rats

Oxidative stress plays important roles in the pathogenesis of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Tat-NR2B9c has shown efficacy as a neuroprotective agent in several studies. Here, we identified the neuroprotective role of Tat-NR2B9c after SAH and its related mechanisms. The results showed that Tat-NR2B9c treatment attenuated oxidative stress, therefore alleviated neuronal apoptosis and neurological deficits after SAH. Tat-NR2B9c treatment could alleviate mitochondrial vacuolization induced by SAH. Compared to SAH + vehicle group, Tat-NR2B9c resulted in the decrease of Acetylated superoxide dismutase2 (Ac-SOD2), Bcl-2-associated X protein (Bax) and cleaved-caspase3 (CC3) protein expression, and the up-regulation of Sirtunin 3 (Sirt3) and Bcl-2 protein level. Moreover, Tat-NR2B9c attenuated excitotoxicity by inhibiting the interaction of PSD95-NR2B-nNOS. Our results demonstrated that Tat-NR2B9c inhibited oxidative stress via inhibition of PSD95-NR2B-nNOS complex formation after SAH. Tat-NR2B9c may serve as a potential treatment for SAH induced brain injury.

Sirtuins as Potential Targets for Neuroprotection: Mechanisms of Early Brain Injury Induced by Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a prevalent cerebrovascular disease with significant global mortality and morbidity rates. Despite advancements in pharmacological and surgical approaches, the quality of life for SAH survivors has not shown substantial improvement. Traditionally, vasospasm has been considered a primary contributor to death and disability following SAH, but anti-vasospastic therapies have not demonstrated significant benefits for SAH patients' prognosis. Emerging studies suggest that early brain injury (EBI) may play a crucial role in influencing SAH prognosis. Sirtuins (SIRTs), a group of NAD + -dependent deacylases comprising seven mammalian family members (SIRT1 to SIRT7), have been found to be involved in neural tissue development, plasticity, and aging. They also exhibit vital functions in various central nervous system (CNS) processes, including cognition, pain perception, mood, behavior, sleep, and circadian rhythms. Extensive research has uncovered the multifaceted roles of SIRTs in CNS disorders, offering insights into potential markers for pathological processes and promising therapeutic targets (such as SIRT1 activators and SIRT2 inhibitors). In this article, we provide an overview of recent research progress on the application of SIRTs in subarachnoid hemorrhage and explore their underlying mechanisms of action.

SIRT3-mediated autophagy contributes to ferroptosis-induced anticancer by inducing the formation of BECN1-SLC7A11 complex

Ferroptosis is an autophagy-dependent cell death associated with iron accumulation and lipid peroxidation, which plays a crucial part in anticancer activity. Sirtuin 3 (SIRT3) positively regulates autophagy by phosphorylation of activated protein kinase (AMPK). However, whether SIRT3-mediated autophagy can inhibit the cystine/glutamate antiporter (system Xc-) activity by inducing the formation of a BECN1-SLC7A11 complex and consequently promote induction of ferroptosis is unknown. Using both in vitro and in vivo models, we revealed that combination treatment with erastin and TGF-β1 decreased the expression of epithelial-mesenchymal transition-related markers and inhibited the invasion and metastasis of breast cancer. Furthermore, TGF-β1 promoted erastin-induced ferroptosis-related indicators in MCF-7 cells and tumor-bearing nude mice models. Interestingly, the expression of SIRT3, p-AMPK, and autophagy-related markers were significantly elevated after co-treatment with erastin and TGF-β1, suggesting that combination treatment of erastin and TGF-β1 mediated autophagy by the SIRT3/AMPK signaling pathway. In addition, erastin-induced BECN1-SLC7A11 complexes were more abundant after co-treatment with TGF-β1. This effect was inhibited by the autophagy inhibitor 3-methyladenine or siSIRT3, further revealing that combination treatment of erastin and TGF-β1 mediated autophagy-dependent ferroptosis by inducing the formation of BECN1-SLC7A11 complexes. Our results agreed with the concept that BECN1 directly binds to SLC7A11 to inhibit system Xc- activity. In summary, our studies confirmed that SIRT3-mediated autophagy is conducive to ferroptosis-mediated anticancer activity by inducing the formation of BECN1-SLC7A11 complexes, which is a potential therapeutic approach for treating breast cancer.

Sirtuin-3: A potential target for treating several types of brain injury

Sirtuin-3 (SIRT3) is responsible for maintaining mitochondrial homeostasis by deacetylating substrates in an NAD+-dependent manner. SIRT3, the primary deacetylase located in the mitochondria, controls cellular energy metabolism and the synthesis of essential biomolecules for cell survival. In recent years, increasing evidence has shown that SIRT3 is involved in several types of acute brain injury. In ischaemic stroke, subarachnoid haemorrhage, traumatic brain injury, and intracerebral haemorrhage, SIRT3 is closely related to mitochondrial homeostasis and with the mechanisms of pathophysiological processes such as neuroinflammation, oxidative stress, autophagy, and programmed cell death. As SIRT3 is the driver and regulator of a variety of pathophysiological processes, its molecular regulation is significant. In this paper, we review the role of SIRT3 in various types of brain injury and summarise SIRT3 molecular regulation. Numerous studies have demonstrated that SIRT3 plays a protective role in various types of brain injury. Here, we present the current research available on SIRT3 as a target for treating ischaemic stroke, subarachnoid haemorrhage, traumatic brain injury, thus highlighting the therapeutic potential of SIRT3 as a potent mediator of catastrophic brain injury. In addition, we have summarised the therapeutic drugs, compounds, natural extracts, peptides, physical stimuli, and other small molecules that may regulate SIRT3 to uncover additional brain-protective mechanisms of SIRT3, conduct further research, and provide more evidence for clinical transformation and drug development.

Environmental microplastic accumulation exacerbates liver ischemia-reperfusion injury in rat: Protective effects of melatonin

Ischemia-reperfusion (IR) injury is an inevitable complication of liver transplantation and partial hepatectomy. Although the hazards of environmental microplastics (EMPs) have been well explored, data underlying their impact on IR-induced hepatotoxicity and how to alleviate these damages remain largely undefined. In this study, the involvement of melatonin (MT) in modulating EMPs toxicity in the liver undergoing ischemia-reperfusion injury was investigated. Male Wistar rats were exposed to MPs for 7 days and then subjected to 1 h of partial warm ischemia (70 %) followed by 24 h of reperfusion. We analyzed some parameters as the oxidative stress, the stability of cytoskeleton as well as inflammation, and autophagy. Our data suggested that EMPs elicited liver injury in ischemic animals. Data revealed several histological alterations caused by EMP and IRI, including cellular disorientation, cell necrosis, and microvacuolar steatosis, as well as inflammatory cell infiltration. EMPs increased blood transaminase (AST and ALT) and oxidative stress levels in the ischemic liver. In addition, RT-qPCR, immunofluorescence, and western blot analyses highlighted an increased expression of α-tubulin, IL-18, NFkB, and LC3. However, the ability of MT to reduce MPs and IRI toxicity was consistent with a significant decrease in the evaluated markers. The combined data not only document that melatonin is an effective agent to protect against hepatic IRI but also reduces cellular dysfunction caused by EMPs.

Role of SIRT3 in neurological diseases and rehabilitation training

Sirtuin3 (SIRT3) is a deacetylase that plays an important role in normal physiological activities by regulating a variety of substrates. Considerable evidence has shown that the content and activity of SIRT3 are altered in neurological diseases. Furthermore, SIRT3 affects the occurrence and development of neurological diseases. In most cases, SIRT3 can inhibit clinical manifestations of neurological diseases by promoting autophagy, energy production, and stabilization of mitochondrial dynamics, and by inhibiting neuroinflammation, apoptosis, and oxidative stress (OS). However, SIRT3 may sometimes have the opposite effect. SIRT3 can promote the transfer of microglia. Microglia in some cases promote ischemic brain injury, and in some cases inhibit ischemic brain injury. Moreover, SIRT3 can promote the accumulation of ceramide, which can worsen the damage caused by cerebral ischemia-reperfusion (I/R). This review comprehensively summarizes the different roles and related mechanisms of SIRT3 in neurological diseases. Moreover, to provide more ideas for the prognosis of neurological diseases, we summarize several SIRT3-mediated rehabilitation training methods.

New Insights of Early Brain Injury after Subarachnoid Hemorrhage: A Focus on the Caspase Family

Spontaneous subarachnoid hemorrhage (SAH), primarily caused by ruptured intracranial aneurysms, remains a prominent clinical challenge with a high rate of mortality and morbidity worldwide. Accumulating clinical trials aiming at the prevention of cerebral vasospasm (CVS) have failed to improve the clinical outcome of patients with SAH. Therefore, a growing number of studies have shifted focus to the pathophysiological changes that occur during the periods of early brain injury (EBI). New pharmacological agents aiming to alleviate EBI have become a promising direction to improve outcomes after SAH. Caspases belong to a family of cysteine proteases with diverse functions involved in maintaining metabolism, autophagy, tissue differentiation, regeneration, and neural development. Increasing evidence shows that caspases play a critical role in brain pathology after SAH. Therefore, caspase regulation could be a potential target for SAH treatment. Herein, we provide an overview pertaining to the current knowledge on the role of caspases in EBI after SAH, and we discuss the promising therapeutic value of caspase-related agents after SAH.

Melatonin as an Antioxidant Agent in Stroke: An Updated Review

Stroke is a devastating disease associated with high mortality and disability worldwide, and is generally classified as ischemic or hemorrhagic, which share certain similar pathophysiological processes. Oxidative stress is a critical factor involved in stroke-induced injury, which not only directly damages brain tissue, but also enhances a series of pathological signaling cascades, contributing to inflammation, brain edema, and neuronal death. To alleviate these serious secondary brain injuries, neuroprotective agents targeting oxidative stress inhibition may serve as a promising treatment strategy. Melatonin is a hormone secreted by the pineal gland, and has various properties, such as antioxidation, anti-inflammation, circadian rhythm modulation, and promotion of tissue regeneration. Numerous animal experiments studying stroke have confirmed that melatonin exerts considerable neuroprotective effects, partially via anti-oxidative stress. In this review, we introduce the possible role of melatonin as an antioxidant in the treatment of stroke based on the latest published studies of animal experiments and clinical research.

Inflammation and immune cell abnormalities in intracranial aneurysm subarachnoid hemorrhage (SAH): Relevant signaling pathways and therapeutic strategies

Intracranial aneurysm subarachnoid hemorrhage (SAH) is a cerebrovascular disorder associated with high overall mortality. Currently, the underlying mechanisms of pathological reaction after aneurysm rupture are still unclear, especially in the immune microenvironment, inflammation, and relevant signaling pathways. SAH-induced immune cell population alteration, immune inflammatory signaling pathway activation, and active substance generation are associated with pro-inflammatory cytokines, immunosuppression, and brain injury. Crosstalk between immune disorders and hyperactivation of inflammatory signals aggravated the devastating consequences of brain injury and cerebral vasospasm and increased the risk of infection. In this review, we discussed the role of inflammation and immune cell responses in the occurrence and development of aneurysm SAH, as well as the most relevant immune inflammatory signaling pathways [PI3K/Akt, extracellular signal-regulated kinase (ERK), hypoxia-inducible factor-1α (HIF-1α), STAT, SIRT, mammalian target of rapamycin (mTOR), NLRP3, TLR4/nuclear factor-κB (NF-κB), and Keap1/nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/ARE cascades] and biomarkers in aneurysm SAH. In addition, we also summarized potential therapeutic drugs targeting the aneurysm SAH immune inflammatory responses, such as nimodipine, dexmedetomidine (DEX), fingolimod, and genomic variation-related aneurysm prophylactic agent sunitinib. The intervention of immune inflammatory responses and immune microenvironment significantly reduces the secondary brain injury, thereby improving the prognosis of patients admitted to SAH. Future studies should focus on exploring potential immune inflammatory mechanisms and developing additional therapeutic strategies for precise aneurysm SAH immune inflammatory regulation and genomic variants associated with aneurysm formation.

Redox Biology of Melatonin: Discriminating Between Circadian and Noncircadian Functions

Melatonin has not only to be seen as a regulator of circadian clocks. In addition to its chronobiotic functions, it displays other actions, especially in cell protection. This includes antioxidant, anti-inflammatory, and mitochondria-protecting effects. Although protection is also modulated by the circadian system, the respective actions of melatonin can be distinguished and differ with regard to dose requirements in therapeutic settings. It is the aim of this article to outline these differences in terms of function, signaling, and dosage. Focus has been placed on both the nexus and the dissecting properties between circadian and noncircadian mechanisms. This has to consider details beyond the classic view of melatonin's role, such as widespread synthesis in extrapineal tissues, formation in mitochondria, effects on the mitochondrial permeability transition pore, and secondary signaling, for example, via upregulation of sirtuins and by regulating noncoding RNAs, especially microRNAs. The relevance of these findings, the differences and connections between circadian and noncircadian functions of melatonin shed light on the regulation of inflammation, including macrophage/microglia polarization, damage-associated molecular patterns, avoidance of cytokine storms, and mitochondrial functions, with numerous consequences to antioxidative protection, that is, aspects of high actuality with regard to deadly viral and bacterial diseases. Antioxid. Redox Signal. 37, 704-725.

Modulation of autophagy by melatonin via sirtuins in stroke: From mechanisms to therapies

Sirtuins perform an important effect on the neural cell fate following stroke. Several mechanisms that have been correlated with stroke are oxidative stress, apoptosis, necrosis and autophagy. Autophagy is usually regarded as unitary of the neural cell survival mechanisms. Recently, the importance of the sirtuins effect on autophagy by antioxidant agents for stroke treatment mentioned in various studies. One of these agents is melatonin. Melatonin can modulate autophagy by changing on sirtuin pathways. Melatonin and its metabolites adjust various sirtuins pathways related to apoptosis, proliferation, metastases, autophagy and inflammation in case of stroke. In this review, we will discuss about the modulation of autophagy by melatonin via sirtuins in stroke.

Melatonin as a Potential Neuroprotectant: Mechanisms in Subarachnoid Hemorrhage-Induced Early Brain Injury

Subarachnoid hemorrhage (SAH) is a common cerebrovascular disease with high mortality and disability rates. Despite progressive advances in drugs and surgical techniques, neurological dysfunction in surviving SAH patients have not improved significantly. Traditionally, vasospasm has been considered the main cause of death and disability following SAH, but anti-vasospasm therapy has not benefited clinical prognosis. Many studies have proposed that early brain injury (EBI) may be the primary factor influencing the prognosis of SAH. Melatonin is an indole hormone and is the main hormone secreted by the pineal gland, with low daytime secretion levels and high nighttime secretion levels. Melatonin produces a wide range of biological effects through the neuroimmune endocrine network, and participates in various physiological activities in the central nervous system, reproductive system, immune system, and digestive system. Numerous studies have reported that melatonin has extensive physiological and pharmacological effects such as anti-oxidative stress, anti-inflammation, maintaining circadian rhythm, and regulating cellular and humoral immunity. In recent years, more and more studies have been conducted to explore the molecular mechanism underlying melatonin-induced neuroprotection. The studies suggest beneficial effects in the recovery of intracerebral hemorrhage, cerebral ischemia-reperfusion injury, spinal cord injury, Alzheimer’s disease, Parkinson’s disease and meningitis through anti-inflammatory, antioxidant and anti-apoptotic mechanisms. This review summarizes the recent studies on the application and mechanism of melatonin in SAH.

The blood-brain barrier and the neurovascular unit in subarachnoid hemorrhage: molecular events and potential treatments

The response of the blood-brain barrier (BBB) following a stroke, including subarachnoid hemorrhage (SAH), has been studied extensively. The main components of this reaction are endothelial cells, pericytes, and astrocytes that affect microglia, neurons, and vascular smooth muscle cells. SAH induces alterations in individual BBB cells, leading to brain homeostasis disruption. Recent experiments have uncovered many pathophysiological cascades affecting the BBB following SAH. Targeting some of these pathways is important for restoring brain function following SAH. BBB injury occurs immediately after SAH and has long-lasting consequences, but most changes in the pathophysiological cascades occur in the first few days following SAH. These changes determine the development of early brain injury as well as delayed cerebral ischemia. SAH-induced neuroprotection also plays an important role and weakens the negative impact of SAH. Supporting some of these beneficial cascades while attenuating the major pathophysiological pathways might be decisive in inhibiting the negative impact of bleeding in the subarachnoid space. In this review, we attempt a comprehensive overview of the current knowledge on the molecular and cellular changes in the BBB following SAH and their possible modulation by various drugs and substances.

An Update on Antioxidative Stress Therapy Research for Early Brain Injury After Subarachnoid Hemorrhage

The main reasons for disability and death in aneurysmal subarachnoid hemorrhage (aSAH) may be early brain injury (EBI) and delayed cerebral ischemia (DCI). Despite studies reporting and progressing when DCI is well-treated clinically, the prognosis is not well-improved. According to the present situation, we regard EBI as the main target of future studies, and one of the key phenotype-oxidative stresses may be called for attention in EBI after laboratory subarachnoid hemorrhage (SAH). We summarized the research progress and updated the literature that has been published about the relationship between experimental and clinical SAH-induced EBI and oxidative stress (OS) in PubMed from January 2016 to June 2021. Many signaling pathways are related to the mechanism of OS in EBI after SAH. Several antioxidative stress drugs were studied and showed a protective response against EBI after SAH. The systematical study of antioxidative stress in EBI after laboratory and clinical SAH may supply us with new therapies about SAH.

Effect of astaxanthin on neuron damage, inflammatory factors expressions and oxidative stress in mice with subarachnoid hemorrhage

OBJECTIVE

This study aimed to explore the effect of astaxanthin (ATX) on neuron damage, inflammatory factor expression and oxidative stress in mice with subarachnoid hemorrhage (SAH).

METHODS

Specific-pathogen-free, 'Institute of Cancer Research', male mice were randomly divided into four groups: SAH group, sham group, SAH + placebo group (SAH + Vehicle group) and SAH + ATX group. Neurological function was scored in each group. Brain water content, reactive oxygen species (ROS) content and inflammatory factor levels in the brain were detected by wet-dry weighting method, DCFH-DA fluorescent probe staining method and ELISA, respectively. Expression of NADPH oxidase 2 (NOX2), glial fibrillary acidic protein (GFAP) and apoptosis-related proteins Bax and Bcl-2 were detected by Western blot and quantitative real-time polymerase chain reaction. Neuronal apoptosis was detected by TUNEL staining.

RESULTS

Compared with sham group, neurological score, brain water content and ROS content in the other three groups increased significantly (all P<0.05). Neurological score, brain water content and ROS content in SAH + ATX group were lower than those in SAH group (all P<0.05). Compared with the sham group, there was increased expression of interleukin (IL)-6, IL-17 and tumor necrosis factor α (TNF-α), and increased neuronal apoptosis, as well as enhanced expression of NOX2, GFAP and Bax; while there was decreased IL-10 expression, and declined Bcl-2 expression, in the other three groups (all P<0.05). There was decreased expression of IL-6, IL-17 and TNF-α, declined expressions of NOX2, GFAP and Bax, and lowered neuronal apoptosis; while there was increased IL-10 expression, and enhanced Bcl-2 expression, in SAH + ATX group as compared to SAH group (all P<0.05). All indicators between SAH group and SAH + Vehicle group showed no significant differences (all P>0.05).

CONCLUSION

Astaxanthin can decrease neuron damage, inhibit inflammatory response, and improve oxidative stress in SAH mice. Thus, astaxanthin is a method for treating SAH.

Melatonin pretreatment alleviates blast-induced oxidative stress in the hypothalamic-pituitary-gonadal axis by activating the Nrf2/HO-1 signaling pathway

Although melatonin has been demonstrated to exert a potent antioxidant effect, the ability of melatonin to alleviate blast-induced oxidative stress in the hypothalamic-pituitary-gonadal (HPG) axis remains unclear. This study aimed to elucidate the effects and underlying mechanism of melatonin pretreatment on the HPG axis disrupted by blast injury. Sixty C57BL/6 mice were randomly divided into control, blast, and blast + melatonin groups for behavioral experiments. The elevated maze experiment, open field experiment, and Morris Water Maze experiment were carried out on the 7th, 14th and 28th day after the blast injury. Fifty Sprague Dawley rats were randomly divided into control, blast, blast + melatonin, and blast + melatonin + luzindole groups for hormone assays and molecular and pathological experiments. Blood samples were used for HPG axis hormone detection and ELISA assays, and tissue samples were used to detect oxidative stress, inflammation, apoptosis, and stress-related protein levels. The results showed that melatonin pretreatment alleviated blast-induced behavioral abnormalities in mice and maintained the HPG axis hormone homeostasis in rats. Additionally, melatonin significantly reduced MDA5 expression and increased the expression of Nrf2/HO-1. Moreover, melatonin significantly inhibited NF-κB expression and upregulated IL-10 expression, and it reversed the blast-induced high expression of caspase-3 and Bax and the low expression of Bcl-2. Furthermore, luzindole counteracted melatonin inhibition of NF-κB and upregulated Nrf2/HO-1. Melatonin significantly alleviated blast-induced HPG axis hormone dyshomeostasis, behavioral abnormalities, oxidative stress, inflammation, and apoptosis, which may be achieved by upregulating the Nrf2/HO-1 signaling pathway. Our study suggested that melatonin pretreatment is a potential treatment for blast-induced HPG axis hormonal and behavioral abnormalities.

Glutamate, Glutamine, GABA and Oxidative Products in the Pons Following Cortical Injury and Their Role in Motor Functional Recovery

Brain injury leads to an excitatory phase followed by an inhibitory phase in the brain. The clinical sequelae caused by cerebral injury seem to be a response to remote functional inhibition of cerebral nuclei located far from the motor cortex but anatomically related to the injury site. It appears that such functional inhibition is mediated by an increase in lipid peroxidation (LP). To test this hypothesis, we report data from 80 rats that were allocated to the following groups: the sham group (n = 40), in which rats received an intracortical infusion of artificial cerebrospinal fluid (CSF); the injury group (n = 20), in which rats received CSF containing ferrous chloride (FeCl₂, 50 mM); and the recovery group (n = 20), in which rats were injured and allowed to recover. Beam-walking, sensorimotor and spontaneous motor activity tests were performed to evaluate motor performance after injury. Lipid fluorescent products (LFPs) were measured in the pons. The total pontine contents of glutamate (GLU), glutamine (GLN) and gamma-aminobutyric acid (GABA) were also measured. In injured rats, the motor deficits, LFPs and total GABA and GLN contents in the pons were increased, while the GLU level was decreased. In contrast, in recovering rats, none of the studied variables were significantly different from those in sham rats. Thus, motor impairment after cortical injury seems to be mediated by an inhibitory pontine response, and functional recovery may result from a pontine restoration of the GLN-GLU-GABA cycle, while LP may be a primary mechanism leading to remote pontine inhibition after cortical injury.

Multi-omics landscape of circadian rhythm pathway alterations in Glioma

Circadian rhythm pathway was demonstrated pathological functions in glioma on single-gene level. We aim to depict the multi-omics landscape of circadian rhythm pathway alteration in glioma using bioinformatic analyses. Multi-omics data were obtained from “cBioPortal” database. Comparisons were done regarding clinical parameters, differential-expressed genes and functional annotations. A pathway index was generated using the expression data from TCGA and GTEx to quantify the general alteration level of the pathway with clinical association of circadian rhythm pathway index explored. A total of 30 genes were mapped on the circadian rhythm pathway. Genomic profile ofcircadian rhythm pathway genes exhibited distinct characteristics on multiple levels between lower grade glioma (LGG) and glioblastoma multiforme (GBM) patients. LGG patients presented significantly higher frequencies of multi-omics mutations, as well as significant clinical relevance, on single-gene level. Differential-expressed genes between LGG and GBM patients revealed different functions between subtypes that related to the alteration of circadian rhythm pathway. LGG have significantly higher pathway index than normal brain tissue, while GBM significantly lower than normal tissue (P < 0.01), indicating distinctly altered circadian pathway in LGG. Circadian rhythm pathway index correlated with the prognosis of LGG, but not GBM, patients, with higher score indicating better survival outcome (LGG: HR = 0.39, 95% CI: 0.26 − 0.59, P < 0.001). In conclusion, LGG have more multi-omics alterations of circadian rhythm pathway than GBM. Quantification of circadian rhythm pathway using pathway index demonstrated hyperactivated pathway status in LGG and correlated with the prognosis of LGG patients.

The cellular immunotherapy of integrated photothermal anti-oxidation Pd-Se nanoparticles in inhibition of the macrophage inflammatory response in rheumatoid arthritis

Reducing the inflammatory response is a major goal in the therapy of rheumatoid arthritis (RA). Herein, we integrated palladium nanoparticles (Pd NPs) with selenium nanoparticles (Se NPs) and obtained a multiple nanosystem (Pd@Se-HA NPs) that could simultaneously scavenge hydroxyl radicals (⋅OH) and provide a photothermal effect. The Pd@Se-HA NPs were constructed by a simple self-assembly method in which Se NPs were electrostatically bonded to Pd NPs; hyaluronic acid (HA) was linked to the NPs by ester bonding to provide macrophage targeting ability. The experiments show that the combined therapy of eliminating ⋅OH with Se NPs and utilizing PTT with Pd NPs could effectively reduce the inflammatory response in macrophages more effectively than either individual NP treatment. In addition, the outer layer of HA could specifically target the CD44 receptor to enhance the accumulation of Pd@Se NPs at the lesion, further enhancing the therapeutic effect. After treatment for 15 days, the Pd@Se-HA NPs nearly eliminated the inflammatory response in the joints of mice in an induced RA model, and prevented joint damage and degradation.

Inhibition of Ferroptosis Alleviates Early Brain Injury After Subarachnoid Hemorrhage In Vitro and In Vivo via Reduction of Lipid Peroxidation

Subarachnoid hemorrhage (SAH) is a serious cerebrovascular disease with high mortality, and the mean age at morbidity is younger than in other types of stroke. Early brain injury (EBI) plays a key role in the poor prognoses of SAH. In EBI, multiple forms of cell death have been identified and well studied; however, the role of ferroptosis has not been elucidated. Hence, in this study, we developed an in vivo (SAH rat model) and in vitro model (SH-SY5Y oxyhemoglobin injury model) to understand the role of ferroptosis in EBI, then explored the protective mechanism of ferrostatin-1 (Fer-1). Firstly, we found that neurological scores, blood-brain barrier permeability, brain edema deteriorated after SAH in the in vivo model, cell viability was decreased after SAH in both cortex and SH-SY5Y cells. Further, iron content in cortex was increased after SAH, while transferrin receptor 1 and ferroportin (Fpn) were increased in oxyhemoglobin-treated in vitro model. Additionally, glutathione content and glutathione peroxidase 4 activity were reduced in SAH rats, and lipid peroxides were increased in the oxyhemoglobin-treated cells. Finally, administration of Fer-1 upregulated Fpn and decreased the iron content, then improved the lipid peroxidation and EBI. However, Fer-1 had no effect on the apoptosis. Our study indicated that the ferroptosis was involved in EBI of SAH, and the inhibitor Fer-1 provided neuroprotection against EBI by alleviating ferroptosis, the potential protective mechanism might be via suppressing lipid peroxidation.

Will Sirtuins Be Promising Therapeutic Targets for TBI and Associated Neurodegenerative Diseases?

Traumatic brain injury (TBI), a leading cause of morbidity worldwide, induces mechanical, persistent structural, and metabolic abnormalities in neurons and other brain-resident cells. The key pathological features of TBI include neuroinflammation, oxidative stress, excitotoxicity, and mitochondrial dysfunction. These pathological processes persist for a period of time after TBIs. Sirtuins are evolutionarily conserved nicotinamide-adenine dinucleotide (NAD+)-dependent deacetylases and mono-ADP-ribosyl transferases. The mammalian sirtuin family has seven members, referred to as Sirtuin (SIRT) 1-7. Accumulating evidence suggests that SIRT1 and SIRT3 play a neuroprotective role in TBI. Although the evidence is scant, considering the involvement of SIRT2, 4-7 in other brain injury models, they may also intervene in similar pathophysiology in TBI. Neurodegenerative diseases are generally accepted sequelae of TBI. It was found that TBI and neurodegenerative diseases have many similarities and overlaps in pathological features. Besides, sirtuins play some unique roles in some neurodegenerative diseases. Therefore, we propose that sirtuins might be a promising therapeutic target for both TBI and associated neurodegenerative diseases. In this paper, we review the neuroprotective effects of sirtuins on TBI as well as related neurodegeneration and discuss the therapeutic potential of sirtuin modulators.

Hydrogen gas inhalation improves delayed brain injury by alleviating early brain injury after experimental subarachnoid hemorrhage

Molecular hydrogen (H₂) protect neurons against reactive oxygen species and ameliorates early brain injury (EBI) after subarachnoid hemorrhage (SAH). This study investigated the effect of H₂ on delayed brain injury (DBI) using the rat SAH + unilateral common carotid artery occlusion (UCCAO) model with the endovascular perforation method. 1.3% H₂ gas (1.3% hydrogen premixed with 30% oxygen and balanced nitrogen) inhalation was performed on days 0 and 1, starting from anesthesia induction and continuing for 2 h on day 0, and starting from anesthesia induction and continuing for 30 min on day 1. EBI was assessed on the basis of brain edema, expression of S100 calcium-binding protein B (S100B), and phosphorylation of C-Jun N-terminal kinase on day 2, and neurological deficits on day 3. Reactive astrogliosis and severity of cerebral vasospasm (CV) were assessed on days 3 and 7. DBI was assessed on the basis of neurological deficits and neuronal cell death on day 7. EBI, reactive astrogliosis, and DBI were ameliorated in the H₂ group compared with the control group. CV showed no significant improvement between the control and H₂ groups. This study demonstrated that H₂ gas inhalation ameliorated DBI by reducing EBI without improving CV in the rat SAH + UCCAO model.

Melatonin pretreatment alleviates renal ischemia-reperfusion injury by promoting autophagic flux via TLR4/MyD88/MEK/ERK/mTORC1 signaling

Autophagy is an important mechanism for cellular homeostasis and survival during pathologic stress conditions in the kidney, such as ischemia-reperfusion (IR) injury. In this study, renal IR was induced in female C57BL/6 mice after melatonin administration. Renal function, histological damage, inflammatory infiltration, cytokine production, oxidative stress, antioxidant capacity, autophagy changing, apoptosis levels, and autophagy-associated intracellular signaling pathway were assessed to evaluate the impact of antecedent melatonin treatment on IR-induced renal injury. The administration of melatonin resulted in significantly preserved renal function, and the protective effect was associated with ameliorated oxidative stress, limited pro-inflammatory cytokine production, and neutrophil and macrophage infiltration. Moreover, autophagic flux was increased after melatonin administration while the apoptosis levels were decreased in the melatonin-pretreated mice. Using TAK-242 and CRX-527, we confirmed that MyD88-dependent TLR4 and MEK/ERK/mTORC1 signaling participated in melatonin-induced autophagy in IR mice. Collectively, our results provide novel evidence that antecedent melatonin treatment provides protection for the kidney against IR injury by enhancing autophagy, as regulated by the TLR4/MyD88/MEK/ERK/mTORC1 signaling pathway. Therefore, melatonin preconditioning offers a potential therapeutic approach to prevent renal IR injury related to various clinical conditions.

Inhibition of the Peroxisome Proliferator-Activated Receptor gamma Coactivator 1-alpha (PGC-1α)/Sirtuin 3 (SIRT3) Pathway Aggravates Oxidative Stress After Experimental Subarachnoid Hemorrhage

Background

Emerging evidence shows that Sirtuin 3 (SIRT3) can exert an antioxidative effect in various neurodegenerative diseases, but whether and how SIRT3 modulates neuronal death after subarachnoid hemorrhage (SAH) remains to be elucidated.

Materia/Methods

Experimental SAH was induced in adult mice by prechiasmatic cistern injection and primary neurons by OxyHb incubation. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and SIRT3 protein levels were examined at different time points after SAH induction. The PGC-1α protein gene knockdown in vivo and in vitro was achieved by transfection of lentivirus (LV) vectors expressing shPGC-1α or negative control (NC). Western blot, oxidative stress index, histopathology, neurological function, and cell viability analysis was performed.

Results

Results showed that the PGC-1α/SIRT3 pathway was remarkably activated in vivo and in vitro after SAH. LV-shPGC-1α treatment significantly inhibited the activation of this pathway after SAH, accompanied by deteriorated neurologic function, aggravated oxidative stress, increased neuronal apoptosis, and enhanced cytotoxicity compared with the mice or primary neurons treated with LV-NC only.

Conclusions

The present results highlight the detrimental PGC-1α/SIRT3 pathway, involving regulation of the endogenous antioxidant activity against neuronal damage, which may provide a potential therapeutic target in SAH.

Daily and seasonal mitochondrial protection: Unraveling common possible mechanisms involving vitamin D and melatonin

From an evolutionary point of view, vitamin D and melatonin appeared very early and share functions related to defense mechanisms. In the current clinical setting, vitamin D is exclusively associated with phosphocalcic metabolism. Meanwhile, melatonin has chronobiological effects and influences the sleep-wake cycle. Scientific evidence, however, has identified new actions of both molecules in different physiological and pathological settings. The biosynthetic pathways of vitamin D and melatonin are inversely related relative to sun exposure. A deficiency of these molecules has been associated with the pathogenesis of cardiovascular diseases, including arterial hypertension, neurodegenerative diseases, sleep disorders, kidney diseases, cancer, psychiatric disorders, bone diseases, metabolic syndrome, and diabetes, among others. During aging, the intake and cutaneous synthesis of vitamin D, as well as the endogenous synthesis of melatonin are remarkably depleted, therefore, producing a state characterized by an increase of oxidative stress, inflammation, and mitochondrial dysfunction. Both molecules are involved in the homeostatic functioning of the mitochondria. Given the presence of specific receptors in the organelle, the antagonism of the renin-angiotensin-aldosterone system (RAAS), the decrease of reactive species of oxygen (ROS), in conjunction with modifications in autophagy and apoptosis, anti-inflammatory properties inter alia, mitochondria emerge as the final common target for melatonin and vitamin D. The primary purpose of this review is to elucidate the common molecular mechanisms by which vitamin D and melatonin might share a synergistic effect in the protection of proper mitochondrial functioning.

Melatonin ameliorates cerebral ischemia/reperfusion injury through SIRT3 activation

AIMS

Previous literature has shown that melatonin plays a critical role in protecting against cerebral ischemia/reperfusion (I/R) injury. Sirtuin3(SIRT3), as one member of the sirtuin family, protects against oxidative stress-related diseases. However, the association between melatonin and SIRT3 in cerebral I/R injury is not well understood. Our experiment was planned to investigate whether melatonin protects against cerebral I/R injury through SIRT3 activation.

MAIN METHODS

We selected transient middle cerebral artery occlusion (tMCAO) mice as the model of cerebral I/R injury. Male C57/BL6 mice were pre-treated with or without a selective SIRT3 inhibitor and then subjected to tMCAO surgery. Melatonin (20 mg/kg) was given to mice by intraperitoneal injection after ischemia and before reperfusion. Then, we observed the changes in the SIRT3 and downstream relative proteins, infarction volume, neurological score, Nissl, H&E and TUNEL staining, and the expression of apoptosis proteins after tMCAO.

KEY FINDINGS

Melatonin upregulated the expression of SIRT3 after tMCAO, and alleviated the neurological dysfunction and cell apoptosis through SIRT3 activation.

SIGNIFICANCE

Our research proved that melatonin promoted SIRT3 expression after tMCAO and alleviated cerebral I/R injury by activating the SIRT3 signaling pathway. This study provides novel therapeutic targets and mechanisms for the treatment of ischemic stroke in the clinic, especially during cerebrovascular reperfusion.

Melatonin May Increase Anticancer Potential of Pleiotropic Drugs

Melatonin (N-acetyl-5-methoxytryptamine) is not only a pineal hormone, but also an ubiquitary molecule present in plants and part of our diet. Numerous preclinical and some clinical reports pointed to its multiple beneficial effects including oncostatic properties, and as such, it has become one of the most aspiring goals in cancer prevention/therapy. A link between cancer and inflammation and/or metabolic disorders has been well established and the therapy of these conditions with so-called pleiotropic drugs, which include non-steroidal anti-inflammatory drugs, statins and peroral antidiabetics, modulates a cancer risk too. Adjuvant therapy with melatonin may improve the oncostatic potential of these drugs. Results from preclinical studies are limited though support this hypothesis, which, however, remains to be verified by further research.

Role and mechanism of ROS scavengers in alleviating NLRP3-mediated inflammation

Inflammation, as a common immune response to various infections or injuries, can cause many dangerous and complicated diseases. Inflammasome is a protein complex playing a vital role in an inflammation process, and the nucleotide-binding oligomerization domain (NOD)-like receptor containing pyrin domain 3 (NLRP3) inflammasome has been the most-widely studied one. Recent evidence suggests the reactive oxygen species (ROS)-NLRP3 signaling pathway to be a possible NLRP3 inflammasome regulation model. Numerous recent preclinical reports indicate that application of antioxidants could scavenge excessive ROS and attenuate inflammatory responses through suppressing NLRP3 inflammasome activation. This article, at first, briefly overviews how ROS may mediate the regulation of NLRP3 inflammasome activation. Then, preclinical researches of various ROS scavengers for treating NLRP3 inflammasome-associated diseases are focused on and critically analyzed. Finally, the potential of antioxidant treatment as a therapy for inflammation is to be discussed, and perspectives on future research directions will be shared.

IL-37b suppresses epithelial mesenchymal transition in hepatocellular carcinoma by inhibiting IL-6/STAT3 signaling

BACKGROUND

Interleukin-37b (IL-37b), a vital negative regulator of the innate immune system, has been reported to be a tumor inhibitor in different type of cancers. However, little is known about the relationship between IL-37b and hepatocellular carcinoma (HCC). The present study aimed to investigate the potential roles of IL-37b in HCC progression.

METHODS

Subjects (n = 237) were recruited, and serum IL-37b was measured using ELISA. The tumor-suppressive capacity and underlying mechanisms of IL-37b in HCC were investigated in vitro and in vivo.

RESULTS

Compared to healthy controls, serum IL-37b levels were elevated in chronic hepatitis B (CHB) patients but decreased significantly in HBV-HCC patients, especially for those with portal venous tumor thrombus. Low level serum IL-37b in HBV-HCC patients correlated with high HCC stage and poor overall survival and disease-free survival. In vitro and in vivo, recombinant human IL-37b inhibited proliferation and metastasis in HCC cells. Furthermore, IL-37b inhibited epithelial mesenchymal transition in HCC cells in vitro by downregulating IL-6, pSTAT3 (Y705), N-cadherin, and vimentin expression and by upregulating E-cadherin expression. These effects were partially reversed by transfection of adenovirus encoding human IL-6.

CONCLUSIONS

IL-37b inhibits HCC growth, metastasis and epithelial mesenchymal transition by regulating IL-6/STAT3 signaling. Serum IL-37b may be a biomarker for HBV-HCC and its staging.