Acupuncture Ameliorates Neuronal Cell Death, Inflammation, and Ferroptosis and Downregulated miR-23a-3p After Intracerebral Hemorrhage in Rats

Acupuncture for poststroke coma: A systematic review and meta-analysis

BACKGROUND

Despite being widely applied in clinical practice, the wake-promoting effect of acupuncture in poststroke coma patients remains controversial.

OBJECTIVE

This study aimed to evaluate the efficacy of acupuncture for the treatment of poststroke coma.

METHODS

Randomized controlled trials (RCTs) of acupuncture for treating poststroke coma were identified in PubMed, Cochrane Library, EMBASE, CNKI, WanFang and VIP up to 25 November 2023. The main outcomes were Glasgow Coma Scale (GCS) score, National Institute of Health Stroke Scale (NIHSS) score, awakening ratio and clinically effective ratio. Stata 17 and Review Manager 5.4 software were used for mate analysis.

RESULTS

A total of 34 RCTs involving 2757 patients were included. GCS (WMD = 1.78; 95% CI: 1.35 to 2.21) and NIHSS score (WMD = -2.84; 95% CI: -3.84 to -1.84) were significantly increased in acupuncture group compared with control group. Acupuncture combined with routine treatment may be better than routine treatment in improving the awakening ratio (RR= 1.65; 95% CI: 1.24 to 2.91) and the clinically effective ratio (RR= 1.20; 95% CI: 1.13 to 1.27). Some methodological flaws were identified in the included studies, including non-implementation of blinding, inappropriate disease assessment and heterogeneous interventions.

CONCLUSIONS

The existing evidence suggests that acupuncture combined with conventional treatment may be an effective treatment for poststroke coma patients. In the meantime, more high-quality RCTs are needed to demonstrate these findings due to methodological weaknesses like randomization, blinding, heterogeneous interventions and long-term follow-up.

Analysis of potential microRNA biomarkers for multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating autoimmune neurodegenerative disorder for which no specific blood biomarker is available. MicroRNAs (miRNAs) have been investigated for their diagnostic potential in MS. However, MS-associated miRNAs are rarely replicated in different MS populations, thus impeding their use in clinical testing. Here, we evaluated the fold expression of seven reported MS miRNAs associated with MS incidence and clinical characteristics in 76 MS patients and 75 healthy control plasma samples. We found miR-23a-3p to be upregulated in relapsing-remitting MS (RRMS), while miR-326 was downregulated. MiR-150-5p and -320a-3p were significantly downregulated in secondary progressive MS (SPMS) patients compared to RRMS. High disability was associated with low miR-320a-3p, whereas low BDNF levels were associated with upregulation of miR-150-5p and downregulation of miR-326 expression in the total cohort. MiR-23a-3p and miR-326 showed significant diagnostic sensitivity, specificity, and accuracy for RRMS diagnosis. In addition, miR-150-5p and miR-320a-3p had comparable significant diagnostic test performance metrics distinguishing SPMS from RRMS. Therefore, there is potential for including miR-23a-3p and miR-326 in an RRMS diagnostic miRNA panel. Moreover, we have shown that miR-150-5p and miR-320a-3p could be novel RRMS conversion to SPMS biomarkers. The use of these miRNAs in MS diagnosis and prognosis warrants further investigation.

The interplay of miRNAs and ferroptosis in diseases related to iron overload

Ferroptosis has been conceptualized as a novel cell death modality distinct from apoptosis, necroptosis, pyroptosis and autophagic cell death. The sensitivity of cellular ferroptosis is regulated at multiple layers, including polyunsaturated fatty acid metabolism, glutathione-GPX4 axis, iron homeostasis, mitochondria and other parallel pathways. In addition, microRNAs (miRNAs) have been implicated in modulating ferroptosis susceptibility through targeting different players involved in the execution or avoidance of ferroptosis. A growing body of evidence pinpoints the deregulation of miRNA-regulated ferroptosis as a critical factor in the development and progression of various pathophysiological conditions related to iron overload. The revelation of mechanisms of miRNA-dependent ferroptosis provides novel insights into the etiology of diseases and offers opportunities for therapeutic intervention. In this review, we discuss the interplay of emerging miRNA regulators and ferroptosis players under different pathological conditions, such as cancers, ischemia/reperfusion, neurodegenerative diseases, acute kidney injury and cardiomyopathy. We emphasize on the relevance of miRNA-regulated ferroptosis to disease progression and the targetability for therapeutic interventions.

Targeting epigenetic and posttranslational modifications regulating ferroptosis for the treatment of diseases

Ferroptosis, a unique modality of cell death with mechanistic and morphological differences from other cell death modes, plays a pivotal role in regulating tumorigenesis and offers a new opportunity for modulating anticancer drug resistance. Aberrant epigenetic modifications and posttranslational modifications (PTMs) promote anticancer drug resistance, cancer progression, and metastasis. Accumulating studies indicate that epigenetic modifications can transcriptionally and translationally determine cancer cell vulnerability to ferroptosis and that ferroptosis functions as a driver in nervous system diseases (NSDs), cardiovascular diseases (CVDs), liver diseases, lung diseases, and kidney diseases. In this review, we first summarize the core molecular mechanisms of ferroptosis. Then, the roles of epigenetic processes, including histone PTMs, DNA methylation, and noncoding RNA regulation and PTMs, such as phosphorylation, ubiquitination, SUMOylation, acetylation, methylation, and ADP-ribosylation, are concisely discussed. The roles of epigenetic modifications and PTMs in ferroptosis regulation in the genesis of diseases, including cancers, NSD, CVDs, liver diseases, lung diseases, and kidney diseases, as well as the application of epigenetic and PTM modulators in the therapy of these diseases, are then discussed in detail. Elucidating the mechanisms of ferroptosis regulation mediated by epigenetic modifications and PTMs in cancer and other diseases will facilitate the development of promising combination therapeutic regimens containing epigenetic or PTM-targeting agents and ferroptosis inducers that can be used to overcome chemotherapeutic resistance in cancer and could be used to prevent other diseases. In addition, these mechanisms highlight potential therapeutic approaches to overcome chemoresistance in cancer or halt the genesis of other diseases.

Baicalein ameliorates oxidative stress and brain injury after intracerebral hemorrhage by activating the Nrf2/ARE pathway via miR-106a-5p/PHLPP2 axis

Intracerebral hemorrhage (ICH) is a devastating stroke subtype. Baicalein (BAI) has been reported to be effective in ischemic stroke. The aim of the present study was to investigate the mechanism of BAI on brain injury after ICH. Firstly, ICH mouse models were established by injecting collagenase into the right of basal ganglia, followed by detection of neurobehavioral scores, brain edema, oxidative stress (OS) level, neuronal apoptosis and pathological changes. Average neurologic scores, brain water content, and blood-brain barrier permeability and MDA level in ICH mice were reduced after BAI treatment, while serum SOD and GSH-Px levels were increased and neuronal apoptosis and pathological injury of the brain tissues were mitigated. miR-106a-5p downregulation averted the effect of BAI on ICH mice. miR-106a-5p targeted PHLPP2 and PHLPP2 overexpression reversed the effect of BAI on ICH mice. BAI activated the Nrf2/ARE pathway by inhibiting PHLPP2 expression. In conclusion, BAI inhibited OS and protected against brain injury after ICH by activating the Nrf2/ARE pathway through the miR-106a-5p/PHLPP2 axis.

The Regulation of Ferroptosis by Noncoding RNAs

As a novel form of regulated cell death, ferroptosis is characterized by intracellular iron and lipid peroxide accumulation, which is different from other regulated cell death forms morphologically, biochemically, and immunologically. Ferroptosis is regulated by iron metabolism, lipid metabolism, and antioxidant defense systems as well as various transcription factors and related signal pathways. Emerging evidence has highlighted that ferroptosis is associated with many physiological and pathological processes, including cancer, neurodegeneration diseases, cardiovascular diseases, and ischemia/reperfusion injury. Noncoding RNAs are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that noncoding RNAs, especially miRNAs, lncRNAs, and circRNAs, can interfere with the progression of ferroptosis by modulating ferroptosis-related genes or proteins directly or indirectly. In this review, we summarize the basic mechanisms and regulations of ferroptosis and focus on the recent studies on the mechanism for different types of ncRNAs to regulate ferroptosis in different physiological and pathological conditions, which will deepen our understanding of ferroptosis regulation by noncoding RNAs and provide new insights into employing noncoding RNAs in ferroptosis-associated therapeutic strategies.

Ischemia/reperfusion-activated ferroptosis in the early stage triggers excessive inflammation to aggregate lung injury in rats

Objective

Lung ischemia/reperfusion injury (LIRI) is a clinical syndrome of acute lung injury that occurs after lung transplantation or remote organ ischemia. Ferroptosis and inflammation are involved in the pathogenesis of LIRI according to the results of several studies on animal models. However, the interactive mechanisms between ferroptosis and inflammation contributing to LIRI remain unclear.

Methods

HE staining and indicators of oxidative stress were used to evaluated the lung injury. The reactive oxygen species (ROS) level was examined by DHE staining. The quantitative Real-time PCR (qRT-PCR) and western blot analysis were employed to detect the level of inflammation and ferroptosis, and deferoxamine (DFO) was used to assess the importance of ferroptosis in LIRI and its effect on inflammation.

Results

In the present study, the link of ferroptosis with inflammation was evaluated at reperfusion 30-, 60- and 180-minute time points, respectively. As the results at reperfusion 30-minute point shown, the pro-ferroptotic indicators, especially cyclooxygenase (COX)-2 and acyl-CoA synthetase long-chain family member 4 (ACSL4), were upregulated while the anti-ferroptotic factors glutathione peroxidase 4 (GPX4), cystine-glumate antiporter (XCT) and ferritin heavy chain (FTH1) were downregulated. Meanwhile, the increased level of interleukin (IL)-6, tumor necrosis factor alpha (TNF-α) and IL-1β were observed beginning at reperfusion 60-minute point but mostly activated at reperfusion 180-minute point. Furthermore, deferoxamine (DFO) was employed to block ferroptosis, which can alleviate lung injury. Expectedly, the survival rate of rats was increased and the lung injury was mitigated containing the improvement of type II alveolar cells ultrastructure and ROS production. In addition, at the reperfusion 180-minute point, the inflammation was observed to be dramatically inhibited after DFO administration as verified by IL-6, TNF-α and IL-1β detection.

Conclusion

These findings suggest that ischemia/reperfusion-activated ferroptosis plays an important role as the trigger for inflammation to further deteriorate lung damages. Inhibiting ferroptosis may have therapeutic potential for LIRI in clinical practice.

MicroRNA-23a-3p is upregulated in plasma exosomes of bulbar-onset ALS patients and targets ERBB4

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease related to the progressive death of motor neurons. Understanding the pathogenesis of ALS continues to provide considerable challenges. Bulbar-onset ALS involves faster functional loss and shorter survival time than spinal cord-onset ALS. However, debate is ongoing regarding typical plasma miRNA changes in ALS patients with bulbar onset. Exosomal miRNAs have not yet been described as a tool for bulbar-onset ALS diagnosis or prognosis prediction. In this study, candidate exosomal miRNAs were identified by small RNA sequencing using samples from patients with bulbar-onset ALS and healthy controls. Potential pathogenic mechanisms were identified through enrichment analysis of target genes for differential miRNAs. Expression of miR-16-5p, miR-23a-3p, miR-22-3p, and miR-93-5p was significantly up-regulated in plasma exosomes from bulbar-onset ALS patients compared with healthy control subjects. Among them, miR-16-5p and miR-23a-3p were significantly lower in spinal-onset ALS patients than those with bulbar-onset. Furthermore, up-regulation of miR-23a-3p in motor neuron-like NSC-34 cells promoted apoptosis and inhibited cell viability. This miRNA was found to directly target ERBB4 and regulate the AKT/GSK3β pathway. Collectively, the above miRNAs and their targets are related to the development of bulbar-onset ALS. Our research indicates that miR-23a-3p might have an effect on motor neuron loss observed in bulbar-onset ALS and may be a novel target for the therapy of ALS in the future.

Epigenetic Regulation of Ferroptosis in Central Nervous System Diseases

Ferroptosis, a newly identified form of cell death, is characterized by iron overload and accumulation of lipid reactive oxygen species. Inactivation of pathways, such as glutathione/glutathione peroxidase 4, NAD(P)H/ferroptosis suppressor protein 1/ubiquinone, dihydroorotate dehydrogenase/ubiquinol, or guanosine triphosphate cyclohydrolase-1/6(R)-L-erythro-5,6,7,8-tetrahydrobiopterin pathways, have been found to induce ferroptosis. The accumulating data suggest that epigenetic regulation can determine cell sensitivity to ferroptosis at both the transcriptional and translational levels. While many of the effectors that regulate ferroptosis have been mapped, epigenetic regulation in ferroptosis is not yet fully understood. Neuronal ferroptosis is a driver in several central nervous system (CNS) diseases, such as stroke, Parkinson's disease, traumatic brain injury, and spinal cord injury, and thus, research on how to inhibit neuronal ferroptosis is required to develop novel therapies for these diseases. In this review, we have summarized epigenetic regulation of ferroptosis in these CNS diseases, focusing in particular on DNA methylation, non-coding RNA regulation, and histone modification. Understanding epigenetic regulation in ferroptosis will hasten the development of promising therapeutic strategies in CNS diseases associated with ferroptosis.

Emerging role of miRNAs in the regulation of ferroptosis

Ferroptosis is a kind of cell death which has distinctive features differentiating it from autophagy, necrosis and apoptosis. This iron-dependent form of cell death is described by an increase in lipid reactive oxygen species, shrinkage of mitochondria and decrease in mitochondrial cristae. Ferroptosis is involved in the initiation and progression of many diseases and is regarded as a hotspot of investigations on treatment of disorders. Recent studies have shown that microRNAs partake in the regulation of ferroptosis. The impact of microRNAs on this process has been verified in different cancers as well as intervertebral disc degeneration, acute myocardial infarction, vascular disease, intracerebral hemorrhage, preeclampsia, hemorrhagic stroke, atrial fibrillation, pulmonary fibrosis and atherosclerosis. miR-675, miR-93, miR-27a, miR-34a and miR-141 have been shown to affect iron metabolism, antioxidant metabolism and lipid metabolism, thus influencing all pivotal mechanisms in the ferroptosis process. In the current review, we summarize the role of microRNAs in ferroptosis and their involvement in the pathetiology of malignant and non-malignant disorders.

MicroRNAs modulate neuroinflammation after intracerebral hemorrhage: Prospects for new therapy

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhagic stroke. After ICH, blood components extravasate from vessels into the brain, activating immune cells and causing them to release a series of inflammatory mediators. Immune cells, together with inflammatory mediators, lead to neuroinflammation in the perihematomal region and the whole brain, and neuroinflammation is closely related to secondary brain injury as well as functional recovery of the brain. Despite recent progress in understanding the pathophysiology of ICH, there is still no effective treatment for this disease. MicroRNAs (miRNAs) are non-coding RNAs 17-25 nucleotides in length that are generated naturally in the human body. They bind complementarily to messenger RNAs and suppress translation, thus regulating gene expression at the post-transcriptional level. They have been found to regulate the pathophysiological process of ICH, particularly the neuroinflammatory cascade. Multiple preclinical studies have shown that manipulating the expression and activity of miRNAs can modulate immune cell activities, influence neuroinflammatory responses, and ultimately affect neurological functions after ICH. This implicates the potentially crucial roles of miRNAs in post-ICH neuroinflammation and indicates the possibility of applying miRNA-based therapeutics for this disease. Thus, this review aims to address the pathophysiological roles and molecular underpinnings of miRNAs in the regulation of neuroinflammation after ICH. With a more sophisticated understanding of ICH and miRNAs, it is possible to translate these findings into new pharmacological therapies for ICH.

Electroacupuncture Reduces Cerebral Hemorrhage Injury in Rats by Improving Cerebral Iron Metabolism

Objective

To study the effects of electroacupuncture at Baihui and Dazhui points on the expression of hepcidin (Hepc), transferrin (Tf), transferrin receptor (TfR), and ferritin (Ft) in rats with cerebral hemorrhage to provide a theoretical basis for the treatment of cerebral hemorrhage with acupuncture.

Method

The model of cerebral hemorrhage in rats was established by autologous blood injection method and treated by electroacupuncture (EA) at the acupoints of Baihui and Dazhui. Hepc siRNA was injected into the lateral ventricle 30 min before model preparation to produce the cerebral hemorrhage model. The modified neurological severity score (mNSS) was used to assess the neurological function, and the total iron content in brain tissue was determined using atomic absorption spectrometry; the expression of Hepc, Ft, Tf, and TfR in perihematoma tissue was detected using immunohistochemistry; the interference efficiency of Hepc siRNA was detected using western blot and reverse transcription polymerase chain reaction (RT-PCR).

Results

The degree of neurological deficit showed a downward trend at 3 days, 7 days, and 14 days, and electroacupuncture significantly reduced the neurological deficit score at each time point (P < 0.01). Regarding total iron content in brain tissue, on the 3rd day, the 7th day, and the 14th day, the iron content of the hematoma tissue after intracerebral hemorrhage was reduced by electroacupuncture (P < 0.01). Regarding immunohistochemical results. Hepc, Ft, Tf, and TfR protein expressions on day 14 were significantly higher after cerebral hemorrhage (P < 0.01). After electroacupuncture, the expression of Hepc, Ft, Tf, and TfR protein was significantly reduced (P < 0.01). Western blot and RT-PCR revealed that the interference efficiency of Hepc siRNA was statistically significant (P < 0.01).

Conclusion

Electroacupuncture can reduce neurological severity scores in rats with cerebral hemorrhage and may exert cerebral protective effects by reducing Hepc protein and gene expression; lowering Ft, Tf, and TfR protein expression; and promoting iron metabolism in the brain of rats with cerebral hemorrhage.

Dexpramipexole Attenuates White Matter Injury to Facilitate Locomotion and Motor Coordination Recovery via Reducing Ferroptosis after Intracerebral Hemorrhage

Deciphering the factors causing damage to white matter fiber bundles and exploring new strategies to alleviate white matter injury (WMI) is a promising treatment to improve neurological impairments after intracerebral hemorrhage (ICH). Ferroptosis usually occurs at perihematomal region and contributes to neuronal death due to reactive oxygen species (ROS) production. Dexpramipexole (DPX) easily crosses the blood brain barrier (BBB) and exerts antioxidative properties by reducing ROS production, while the role of DPX in ferroptosis after ICH remains elusive. Here, our results indicated that ferroptosis played a significant role in WMI resulting from iron and ROS accumulation around hematoma. Further evidence demonstrated that the administration of DPX decreased iron and ROS deposition to inhibit ferroptosis at perihematomal site. With the inhibition of ferroptosis, WMI was alleviated at perihematomal site, thereafter promoting locomotion and motor coordination recovery in mice after ICH. Subsequently, the results showcased that the expression of glutathione peroxidase 4 (GPX4) and ferroptosis suppressing protein 1 (FSP1) was upregulated with the administration of DPX. Collectively, the present study uncovers the underlying mechanism and elucidates the therapeutic effect of DPX on ICH, and even in other central nervous system (CNS) diseases with the presence of ferroptosis.

Downregulation of miR-23a-3p improves cognitive function in rats after subarachnoid hemorrhage by targeting VCAN

Subarachnoid hemorrhage (SAH) is a complicated and deadly disorder. Dysregulation of miRNAs in SAH has been widely reported. This investigation elucidated the function of miR-23a-3p in the in vivo and in vitro models of SAH. The miR-23a-3p and VCAN levels in SAH rats and sham controls were detected by RT-qPCR. The SAH rats were intracerebrally administrated with miR-23a-3p antagomir. Morphological changes and brain function were assessed. The isolated brain microvascular endothelial cells (BMECs), identified by immunofluorescence staining, were used as the model of SAH in vitro. The viability and apoptosis of BMECs were evaluated using MTT, flow cytometry, and western blotting analyses. Targeted relationship between miR-23a-3p and VCAN was predicted in miRDB and validated by a luciferase reporter assay. We found that the miR-23a-3p level was upregulated in rats after SAH, while VCAN was downregulated. Silencing miR-23a-3p attenuated neurological deficits and neuronal apoptosis in rats after SAH. VCAN was verified to be targeted by miR-23a-3p. Functionally, miR-23a-3p downregulation or VCAN overexpression inhibited BMEC apoptosis and promoted cell activity. Moreover, knockdown of VCAN eliminated the influence of miR-23a-3p inhibition in BMECs. Overall, suppression of miR-23a-3p improves cognitive function after SAH by targeting VCAN.

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.

The Anti-Inflammatory Actions and Mechanisms of Acupuncture from Acupoint to Target Organs via Neuro-Immune Regulation

Inflammation plays a significant role in the occurrence and development of multiple diseases. This study comprehensively reviews and presents literature from the last five years, showing that acupuncture indeed exerts strong anti-inflammatory effects in multiple biological systems, namely, the immune, digestive, respiratory, nervous, locomotory, circulatory, endocrine, and genitourinary systems. It is well known that localized acupuncture-mediated anti-inflammatory effects involve the regulation of multiple populations and functions of immune cells, including macrophages, granulocytes, mast cells, and T cells. In acupuncture stimulation, macrophages transform from the M1 to the M2 phenotype and the negative TLR4 regulator PPARγ is activated to inhibit the intracellular TLR/MyD88 and NOD signaling pathways. The downstream IκBα/NF-κB and P38 MAPK pathways are subsequently inhibited by acupuncture, followed by suppressed production of inflammasome and proinflammatory mediators. Acupuncture also modulates the balance of helper T cell populations. Furthermore, it inhibits oxidative stress by enhancing SOD activity via the Nrf2/HO-1 pathway and eliminates the generation of oxygen free radicals, thereby preventing inflammatory cell infiltration. The anti-inflammatory effects of acupuncture on different biological systems are also specific to individual organ microenvironments. As part of its anti-inflammatory action, acupuncture deforms connective tissue and upregulates the secretion of various molecules in acupoints, further activating the NF-κB, MAPK, and ERK pathways in mast cells, fibroblasts, keratinocytes, and monocytes/macrophages. The somatic afferents present in acupuncture-activated acupoints also convey sensory signals to the spinal cord, brainstem, and hypothalamic neurons. Upon information integration in the brain, acupuncture further stimulates multiple neuro-immune pathways, including the cholinergic anti-inflammatory, vagus-adrenal medulla-dopamine, and sympathetic pathways, as well as the hypothalamus-pituitary-adrenal axis, ultimately acting immune cells via the release of crucial neurotransmitters and hormones. This review provides a scientific and reliable basis and viewpoints for the clinical application of acupuncture in various inflammatory conditions.

Scalp Acupuncture Attenuates Brain Damage After Intracerebral Hemorrhage Through Enhanced Mitophagy and Reduced Apoptosis in Rats

To study the effect of scalp acupuncture (SA) on the mitophagy signaling pathway in the caudate nucleus of Sprague-Dawley rats following intracerebral hemorrhage (ICH). An ICH model was established by injecting autologous arterial blood into the caudate nucleus in 200 male Sprague-Dawley rats, which were divided into five groups: sham, ICH, 3-methyladenine group (3-MA, 30 mg/kg), SA, and SA+3-MA. Animals were analyzed at 6 and 24 h as well as at 3 and 7 days. Composite neurological scale score was significantly higher in the SA group than in the ICH group. Transmission electron microscopy showed less structural damage and more autophagic vacuoles within brain in the SA group than in the ICH group. SA group showed higher levels of Beclin1, Parkin, PINK1, NIX protein, and a lower level of Caspase-9 in brain tissue. These animals consequently showed less neural cell apoptosis. Compared with the SA group, however, the neural function score and levels of mitophagy protein in the SA+3-MA group were decreased, neural cell apoptosis was increased with more severe structural damage, which suggested that 3-MA may antagonize the protective effect of SA on brain in rats with ICH. SA may mitigate the neurologic impairment after ICH by enhancing mitophagy and reducing apoptosis.

Dysregulation of microRNA and Intracerebral Hemorrhage: Roles in Neuroinflammation

Intracerebral hemorrhage (ICH) is a major public health problem and devastating subtype of stroke with high morbidity and mortality. Notably, there is no effective treatment for ICH. Neuroinflammation, a pathological hallmark of ICH, contributes to both brain injury and repair and hence, it is regarded as a potential target for therapeutic intervention. Recent studies document that microRNAs, small non-coding RNA molecules, can regulate inflammatory brain response after ICH and are viable molecular targets to alter brain function. Therefore, there is an escalating interest in studying the role of microRNAs in the pathophysiology of ICH. Herein, we provide, for the first time, an overview of the microRNAs that play roles in ICH-induced neuroinflammation and identify the critical knowledge gap in the field, as it would help design future studies.

The Role of Non-Coding RNAs in the Neuroprotective Effects of Glutathione

The establishment of antioxidative defense systems might have been mandatory for most living beings with aerobic metabolisms, because oxygen consumption produces adverse byproducts known as reactive oxygen species (ROS). The brain is especially vulnerable to the effect of ROS, since the brain has large amounts of unsaturated fatty acids, which are a target of lipid oxidation, as well as comparably high-energy consumption compared to other organs that results in ROS release from mitochondria. Thus, dysregulation of the synthesis and/or metabolism of antioxidants-particularly glutathione (GSH), which is one of the most important antioxidants in the human body-caused oxidative stress states that resulted in critical diseases, including neurodegenerative diseases in the brain. GSH plays crucial roles not only as an antioxidant but also as an enzyme cofactor, cysteine storage form, the major redox buffer, and a neuromodulator in the central nervous system. The levels of GSH are precisely regulated by uptake systems for GSH precursors as well as GSH biosynthesis and metabolism. The rapid advance of RNA sequencing technologies has contributed to the discovery of numerous non-coding RNAs with a wide range of functions. Recent lines of evidence show that several types of non-coding RNAs, including microRNA, long non-coding RNA and circular RNA, are abundantly expressed in the brain, and their activation or inhibition could contribute to neuroprotection through the regulation of GSH synthesis and/or metabolism. Interestingly, these non-coding RNAs play key roles in gene regulation and growing evidence indicates that non-coding RNAs interact with each other and are co-regulated. In this review, we focus on how the non-coding RNAs modulate the level of GSH and modify the oxidative stress states in the brain.