Hydrogen inhalation protects hypoxic-ischemic brain damage by attenuating inflammation and apoptosis in neonatal rats

The role of hydrogen in the prevention and treatment of coronary atherosclerotic heart disease

Coronary atherosclerotic heart disease (CHD) is a primary cardiovascular disease caused by atherosclerosis (AS), which is characterized by chronic inflammation and lipid oxidative deposition. Molecular hydrogen (H2) is an effective anti-inflammatory agent and has potential to ameliorate glycolipid metabolism disorders, which is believed to exert beneficial effects on the prevention and treatment of CHD. It is suggested that H2 reduces inflammation in CHD by regulating multiple pathways, including NF-κB inflammatory pathway, pyroptosis, mitophagy, endoplasmic reticulum (ER) stress, and Nrf2 antioxidant pathway. Additionally, H2 may improve glycolipid metabolism by mediation of PI3K and AMPK signalling pathways, contributing to inhibition of the occurrence and development of CHD. This review elaborates pathogenesis of CHD and evaluates the role of H2 in CHD. Moreover, possible molecular mechanisms have been discussed and speculated, aiming to provide more strategies and directions for subsequent studies of H2 in CHD.

Magnesium implantation as a continuous hydrogen production generator for the treatment of myocardial infarction in rats

Molecular hydrogen is an emerging broad-spectrum antioxidant molecule that can be used to treat myocardial infarction (MI). However, with hydrogen inhalation, the concentration that can be reached within target organs is low and the duration of action is short, which makes it difficult to achieve high dose targeted delivery of hydrogen to the heart, seriously limiting the therapeutic potential of hydrogen for MI. As a result of reactions with the internal environment of the body, subcutaneous implantation of magnesium slices leads to continuous endogenous hydrogen production, leading to a higher hydrogen concentration and a longer duration of action in target organs. In this study, we propose magnesium implant-based hydrogen therapy for MI. After subcutaneous implantation of magnesium slices in the dorsum of rats, we measured hydrogen production and efficiency, and evaluated the safety of this approach. Compared with hydrogen inhalation, it significantly improved cardiac function in rats with MI. Magnesium implantation also cleared free radicals that were released as a result of mitochondrial dysfunction, as well as suppressing cardiomyocyte apoptosis.

Mesenchymal Stem Cell Priming: Potential Benefits of Administration of Molecular Hydrogen

Stem cell therapy has emerged as a promising avenue for regenerative medicine, offering the potential to treat a wide range of debilitating diseases and injuries. Among the various types of stem cells, mesenchymal stem cells (MSCs) have garnered significant attention due to their unique properties and therapeutic potential. In recent years, researchers have been exploring novel approaches to enhance the effectiveness of MSC-based therapies. One such approach that has gained traction is the priming of MSCs with molecular hydrogen (H2). This article delves into the fascinating world of mesenchymal stem cell priming with molecular hydrogen and the potential benefits it holds for regenerative medicine.

The Therapeutic Application of Hydrogen in Cancer: The Potential and Challenges

Hydrogen therapy has emerged as a possible approach for both preventing and treating cancer. Cancers are often associated with oxidative stress and chronic inflammation. Hydrogen, with its unique physiological functions and characteristics, exhibits antioxidant, anti-inflammatory, and anti-apoptotic properties, making it an attractive candidate for cancer treatment. Through its ability to mitigate oxidative damage, modulate inflammatory responses, and sustain cellular viability, hydrogen demonstrates significant potential in preventing cancer recurrence and improving treatment outcomes. Preclinical studies have shown the efficacy of hydrogen therapy in several cancer types, highlighting its ability to enhance the effectiveness of conventional treatments while reducing associated side effects. Furthermore, hydrogen therapy has been found to be safe and well-tolerated in clinical settings. Nonetheless, additional investigations are necessary to improve a comprehensive understanding of the mechanisms underlying hydrogen's therapeutic potential and refine the administration and dosage protocols. However, further clinical trials are still needed to explore its safety profile and capacity. In aggregate, hydrogen therapy represents an innovative and promising treatment for several malignancies.

Ferrostatin-1 attenuates hypoxic-ischemic brain damage in neonatal rats by inhibiting ferroptosis

Background

Hypoxic-ischemic brain damage (HIBD) is a type of brain damage that is caused by perinatal asphyxia and serious damages the central nervous system. At present, there is no effective drug for the treatment of this disease. Besides, the pathogenesis of HIBD remains elusive. While studies have shown that ferroptosis plays an important role in HIBD, its role and mechanism in HIBD are yet to be fully understood.

Methods

The HIBD model of neonatal rats was established using the Rice-Vannucci method. A complete medium of PC12 cells was adjusted to a low-sugar medium, and the oxygen-glucose deprivation model was established after continuous hypoxia for 12 h. Laser Doppler blood flow imaging was used to detect the blood flow intensity after modeling. 2,3,5-triphenyl tetrazolium chloride staining was employed to detect ischemic cerebral infarction in rat brain tissue, and hematoxylin and eosin staining and transmission electron microscopy were used to observe brain injury and mitochondrial damage. Immunofluorescence was applied to monitor the expression of GFAP. Real-time quantitative polymerase chain reaction, western blot, and immunofluorescence were utilized to detect the expression of messenger RNA and protein. The level of reactive oxygen species (ROS) in cells was detected using the ROS detection kit.

Results

The results showed that ferrostatin-1 (Fer-1) significantly alleviated the brain injury caused by hypoxia and ischemia. Fer-1 significantly increased the expression of SLC3A2, SLC7A11, ACSL3, GSS, and GPX4 (P<0.05) and dramatically decreased the expressions of GFAP, ACSL4, TFRC, FHC, FLC, 4-HNE, HIF-1α, and ROS (P<0.05).

Conclusions

Fer-1 inhibits ferroptosis and alleviates HIBD by potentially targeting the GPX4/ACSL3/ACSL4 axis; however, its specific mechanism warrants further exploration.

K252a Prevents Microglial Activation Induced by Anoxic Stimulation of Carotid Bodies in Rats

Inducing carotid body anoxia through the administration of cyanide can result in oxygen deprivation. The lack of oxygen activates cellular responses in specific regions of the central nervous system, including the Nucleus Tractus Solitarius, hypothalamus, hippocampus, and amygdala, which are regulated by afferent pathways from chemosensitive receptors. These receptors are modulated by the brain-derived neurotrophic factor receptor TrkB. Oxygen deprivation can cause neuroinflammation in the brain regions that are activated by the afferent pathways from the chemosensitive carotid body. To investigate how microglia, a type of immune cell in the brain, respond to an anoxic environment resulting from the administration of NaCN, we studied the effects of blocking the TrkB receptor on this cell-type response. Male Wistar rats were anesthetized, and a dose of NaCN was injected into their carotid sinus to induce anoxia. Prior to the anoxic stimulus, the rats were given an intracerebroventricular (icv) infusion of either K252a, a TrkB receptor inhibitor, BDNF, or an artificial cerebrospinal fluid (aCSF). After the anoxic stimulus, the rats were perfused with paraformaldehyde, and their brains were processed for microglia immunohistochemistry. The results indicated that the anoxic stimulation caused an increase in the number of reactive microglial cells in the hypothalamic arcuate, basolateral amygdala, and dentate gyrus of the hippocampus. However, the infusion of the K252a TrkB receptor inhibitor prevented microglial activation in these regions.

Ginsenoside Rb1 inhibits ferroptosis to ameliorate hypoxic-ischemic brain damage in neonatal rats

Hypoxic ischemic encephalopathy (HIE) is among the leading causes of neonatal mortality, and currently there is no effective treatment. Ginsenoside Rb1 (GsRb1) is one of the principal active components of ginseng, and has protective benefits against oxidative stress, inflammation, hypoxic injury, and so on. However, the role and underlying mechanism of GsRb1 on HIE are unclear. Here, we established the neonatal rat hypoxic-ischemic brain damage (HIBD) model in vivo and the PC12 cell oxygen-glucose deprivation (OGD) model in vitro to investigate the neuroprotective effects of GsRb1 on HIE, and illuminate the potential mechanism. Our results showed that GsRb1 and the ferroptosis inhibitor liproxstatin-1 (Lip-1) could significantly restore System Xc activity and antioxidant levels as well as inhibit lipid oxidation levels and inflammatory index levels of HIBD and OGD models. Taken together, GsRb1 might inhibit ferroptosis to exert neuroprotective effects on HIE through alleviating oxidative stress and inflammation, which will set the foundation for future research on ferroptosis by reducing hypoxic-ischemic brain injury and suggest that GsRb1 might be a promising therapeutic agent for HIE.

Hydrogen-Rich Saline Attenuates Chronic Allodynia after Bone Fractures via Reducing Spinal CXCL1/CXCR2-Mediated Iron Accumulation in Mice

PURPOSE

Neuroinflammation often initiates iron overload in the pathogenesis of neurological disorders. Chemokine-driven neuroinflammation is required for central sensitization and chronic allodynia following fractures, but specific molecular modulations are elusive. This present study explored whether hydrogen-rich saline, as one potent anti-inflammatory pharmaceutical, could alleviate fracture-caused allodynia by suppressing chemokine CXCL1 expression and iron overload.

METHODS

A mouse model of tibial fracture with intramedullary pinning was employed for establishing chronic allodynia. Three applications of hydrogen-rich saline (1, 5 or 10 mL/kg) were administrated intraperitoneally on a daily basis from days 4 to 6 following fractures. Spinal CXCL1 and its receptor CXCR2 levels, transferrin receptor 1 (TfR1) expression and iron concentration were examined. Recombinant CXCL1, a selective CXCR2 antagonist and an iron chelator were used for verification of mechanisms.

RESULTS

Repetitive injections of hydrogen-rich saline (5 and 10 mL/kg but not 1 mL/kg) prevent fracture-caused mechanical allodynia and cold allodynia in a dose-dependent manner. Single exposure to hydrogen-rich saline (10 mL/kg) on day 14 after orthopedic surgeries controls the established persistent fracture allodynia. Furthermore, hydrogen-rich saline therapy reduces spinal CXCL1/CXCR2 over-expression and TfR1-mediated iron accumulation in fracture mice. Spinal CXCR2 antagonism impairs allodynia and iron overload following fracture surgery. Intrathecal delivery of recombinant CXCL1 induces acute allodynia and spinal iron overload, which is reversed by hydrogen-rich saline. Moreover, iron chelation alleviates exogenous CXCL1-induced acute pain behaviors.

CONCLUSIONS

These findings identify that hydrogen-rich saline confers protection against fracture-caused chronic allodynia via spinal down-modulation of CXCL1-dependent TfR1-mediated iron accumulation in mice.

Bioinformatics-based analysis reveals IDR-1018-mediated ceRNA regulation network for protective effect on hypoxia-ischemic brain injury in neonatal mice

Activation of an innate immune response serves as a key, contributing factor in perinatal brain injury. The current study sought to evaluate the clinical significance of innate defense regulatory peptide 1018 (IDR-1018)-derived peptide mediating ceRNA regulation network as a biomarker in neonatal mice with hypoxic-ischemic brain damage (HIBD). Firstly, bioinformatics analyses were performed to screen the HIBD-related candidate genes, miRNAs, and lncRNAs. The StarBase, miRDB, and LncBase databases were retrieved to obtain the lncRNA-miRNA-mRNA network, which revealed the ceRNA regulatory network mediated by IDR-1018. Subsequently, RT-qPCR was adopted to determine the expression patterns of MIAT, miR-7a-5p, and Plp2 in neonatal mice with HIBD after treatment with IDR-1018. Moreover, the relationship among mRNA, miRNA, and lncRNA in primary hippocampal neurons was verified by means of dual-luciferase reporter assay and RIP assay. Initial findings demonstrated that Plp2, mmu-miR-7a-5p, and three lncRNAs (MIAT, XIST, and 1700020I14RIK) were related to HIBD. Moreover, IDR-1018 could relieve HIBD in neonatal mice. Plp2 and MIAT were down-regulated, while mmu-miR-7a-5p was up-regulated in the striatum, hippocampus, and cortical tissues of the neonatal mice with HIBD, whereas treatment with the IDR-1018 could revere these trends. Additionally, MIAT acted as a ceRNA of miR-7a-5p to elevate Plp2 expression. In conclusion, our findings highlighted that IDR-1018 relieved HIBD in neonatal mice via the MIAT/miR-7a-5p/Plp2 axis.

Octadecaneuropeptide Alleviates Motor and Cognitive Impairments in Neonatal Rats Following Hypoxic-Ischemic Brain Damage

Hypoxic-ischemic brain damage (HIBD) is among the leading causes of neonatal brain injury. ODN, a peptide derived from diazepam-binding inhibitor (DBI), has potent antioxidant and anti-apoptotic properties. It remains unclear, however, whether ODN is an effective treatment for HIBD. Here, we reported that treatment with ODN (10 ng/day, i.c.v.) alleviated the deficits in myodynamia and motor coordination and cognitive functions in HIBD. Meanwhile, ODN prevented the neuronal loss in the cortex and hippocampus in HIBD rats. In addition, ODN decreased ROS by generating less oxidants and more antioxidants, as reflected by a dramatic increase in total antioxidant capacity, glutathione reductase, and catalase and a marked decrease in H₂O₂ and total nitric oxide synthase. Collectively, these data show ODN alleviates neuron injury and motor and memory deficits by attenuating ROS production and could be used as a novel molecular for treating HIBD.

Hydrogen Attenuated Inflammation Response and Oxidative in Hypoxic Ischemic Encephalopathy via Nrf2 Mediated the Inhibition of NLRP3 and NF-κB

Hypoxia and ischemia cause neonatal encephalopathy and brain injury and can further result in cerebral palsy, cognitive impairment, growth restriction, and epilepsy. Induction of neuroprotection is a crucial therapeutic strategy for the treatment of perinatal hypoxic-ischaemic encephalopathy (HIE). Hydrogen has neuroprotective effects against brain-related diseases. Inflammation and oxidative stress are the two main pathophysiological mechanisms in neonatal hypoxic-ischaemic injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an endogenous redox-sensitive transcription factor that participates in the antioxidant defence system through its effects on inflammation and oxidative stress. Herein, the research focuses on the mechanisms by which Nrf2 participates in the protection of hydrogen against HIE. The model of HIE was established by ligation of the right carotid artery and hypoxia in wild-type (WT) and Nrf2-/- mice. First, Nrf2 pathway activity was detected after hypoxia-ischaemia (HI) followed or not by hydrogen treatment. Brain injury, apoptosis, the inflammatory response, oxidative stress injury, and learning and memory function were assayed. We found that HI induced Nrf2 expression and signalling activation. Hydrogen alleviated the infarction volume, brain water content, neurological scores, apoptosis and long-term learning and memory functions after HI in WT mice but not in Nrf2-/- mice. Moreover, the oxidative products reactive oxygen species (ROS) and malondialdehyde (MDA) and the cytokines tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and High mobility group box 1 (HMGB1) were reduced and the antioxidant enzymes Superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) were upregulated by hydrogen treatment after HI in WT mice, but not in Nrf2-/- mice. In addition, the absence of Nrf2 abolished the suppressive effect of hydrogen on the expression of Nacht, Lrr, and Pyd domains-containing protein 3 (NLRP3) pathway members and p65 NF-κB after HI. Taken together, our findings showed that hydrogen alleviated cellular injury and apoptosis, neurobehavioural deficits, the inflammatory response and oxidative stress via the Nrf2-mediated NLRP3 and NF-κB pathways.

Overexpression of Long Noncoding RNA H19 Inhibits Cardiomyocyte Apoptosis in Neonatal Rats with Hypoxic-Ischemic Brain Damage Through the miR-149-5p/LIF/PI3K/Akt Axis

Hypoxic-ischemic brain damage (HIBD) is a leading cause of fatality and neural system injury in neonates. This study aims to explore the effect of long noncoding RNA H19 on cardiomyocyte apoptosis in neonatal rats with HIBD. The neonatal rat model of HIBD was established. The cerebral infarction volume and apoptosis index of cardiomyocyte increased, while H19 expression decreased in neonatal rats with HIBD. After the lentivirus vector of overexpressed H19 was injected into neonatal rats with HIBD, the cardiomyocyte apoptosis was suppressed; levels of inflammatory factors and oxidative stress injury of myocardial tissues were reduced. The binding relationships between H19 and miR-149-5p, and miR-149-5p and leukemia inhibitory factor (LIF) were predicted by a bioinformatics website and verified using the dual-luciferase reporter gene assay. H19 competitively bound to miR-149-5p to upregulate LIF expression and activate the PI3K/Akt pathway. Moreover, a functional rescue experiment was carried out. Injection of Wortmannin reversed the inhibitory effect of H19 overexpression on cardiomyocyte apoptosis in neonatal rats with HIBD. It could be concluded that H19 competitively bound to miR-149-5p to upregulate LIF expression and activate the PI3K/Akt pathway, thus reducing cardiomyocyte apoptosis in neonatal rats with HIBD. This study may offer new insights for HIBD treatment.

Hydrogen-induced Neuroprotection in Neonatal Hypoxic-ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE) remains to be a major cause of morbidity, mortality and severe neurodevelopmental disability in term neonates. Moderate whole body hypothermia is an established, effective neuroprotective therapy to reduce mortality and long-term disability associated with HIE, however, research for adjunct therapies is still warranted to complement the effect of hypothermia. In the last decade, molecular hydrogen emerged as a simple, available, inexpensive substance with advantageous pharmacokinetics to ameliorate hypoxic-ischemic cellular damage. The present review examines the preclinical studies employing hydrogen to combat the deleterious consequences of hypoxic-ischemic insults in rodent and piglet HIE models. Hydrogen exerted unequivocal neuroprotective actions shown by preserved neurovascular function, neuronal viability, and neurocognitive functions in virtually all model species and hypoxic-ischemic insult types tested. Administration of hydrogen started in most studies after the hypoxic-ischemic insult enhancing the translational value of the findings. Among the explored mechanisms of hydrogen-induced neuroprotection, antioxidant, anti- apoptotic and anti-inflammatory effects appeared to be dominant. Unfortunately, the additive neuroprotective effect of hydrogen and therapeutic hypothermia has not yet been demonstrated, thus such studies are warranted to promote the clinical testing of molecular hydrogen as an adjunct neuroprotective treatment of HIE.

Hydrogen (H2) Alleviates Osteoarthritis by Inhibiting Apoptosis and Inflammation via the JNK Signaling Pathway

BACKGROUND

Osteoarthritis (OA) is a very common condition and leads to joint pain, disability, and price tag all over the world. Pathogenesis of OA is closely related to numerous inflammatory and apoptosis cytokines. Hydrogen (H2) reportedly exhibits a diversity of effects such as anti-apoptotic, anti-inflammatory, and anti-oxidative properties via the JNK pathway. However, it is unknown whether H2 has a protective effect against OA via the JNK signaling pathway. Therefore, the aim of this study was to figure out whether hydrogen has protective effect on chondrocyte and further explore the possible underlying mechanism.

METHODS

The chondrocytes were obtained from the human cartilage tissues. Cells were stimulated by TBHP and treated with hydrogen. In vitro treatment effects were evaluated by Western blot assay, real-time PCR, immunofluorescence and TUNEL method. We conducted mice model of destabilization of the medial meniscus (DMM) and treated with hydrogen. In vivo treatment effects were evaluated by X-ray imaging assay, safranin O (SO) staining, TUNEL staining and immunohistochemical assay.

RESULTS

Our results showed that hydrogen can inhibit inflammatory factors (ADAMTS5 and MMP13) and apoptosis factors (cleaved caspase-3, cytochrome c, and Bax) in TBHP-induced chondrocytes. Furthermore, hydrogen can suppress the activation of JNK signaling pathway, whereas the effect of hydrogen can be abolished by anisomycin (a JNK activator). In vivo results showed that hydrogen can down-regulate the expression of p-JNK and cleaved caspase-3 expression.

CONCLUSION

We uncovered that hydrogen (H2) could alleviate apoptosis response and ECM degradation in human chondrocytes via inhibiting the activation of the JNK signaling pathway. Meanwhile, in the surgically-induced DMM mice model, treatment with hydrogen (H2) performed a significant role in OA progression.

RETRACTED: MicroRNA-29a-3p strengthens the effect of dexmedetomidine on improving neurologic damage in newborn rats with hypoxic-ischemic brain damage by inhibiting HDAC4

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 2B+E, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0). The journal requested the corresponding author comment on these concerns and provide the raw data. However, the authors were not responsive to the request for comment. Since original data could not be provided, the overall validity of the results could not be confirmed. Therefore, the Editor-in-Chief decided to retract the article.

NLRP3 Inflammasome and Its Critical Role in Gynecological Disorders and Obstetrical Complications

Inflammasomes, intracellular, multimeric protein complexes, are assembled when damage signals stimulate nucleotide-binding oligomerization domain receptors (NLRs). Several inflammasomes have been reported, including the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), NLRP1, NLRP7, ice protease-activating factor (IPAF), absent in melanoma 2 (AIM2) and NLR family CARD domain-containing protein 4 (NLRC4). Among these inflammasomes, the NLRP3 inflammasome is the most well-studied in terms of structure and function. Unlike other inflammasomes that can only be activated by a finite number of pathogenic microorganisms, the NLRP3 inflammasome can be activated by the imbalance of the internal environment and a large number of metabolites. The biochemical function of NLRP3 inflammasome is to activate cysteine-requiring aspartate proteinase-1 (caspase-1), which converts pro-IL-1β and pro-IL-18 into their active forms, namely, IL-1β and IL-18, which are then released into the extracellular space. The well-established, classic role of NLRP3 inflammasome has been implicated in many disorders. In this review, we discuss the current understanding of NLRP3 inflammasome and its critical role in gynecological disorders and obstetrical complications.

Inhaled H2 or CO2 Do Not Augment the Neuroprotective Effect of Therapeutic Hypothermia in a Severe Neonatal Hypoxic-Ischemic Encephalopathy Piglet Model

Hypoxic-ischemic encephalopathy (HIE) is still a major cause of neonatal death and disability as therapeutic hypothermia (TH) alone cannot afford sufficient neuroprotection. The present study investigated whether ventilation with molecular hydrogen (2.1% H2) or graded restoration of normocapnia with CO2 for 4 h after asphyxia would augment the neuroprotective effect of TH in a subacute (48 h) HIE piglet model. Piglets were randomized to untreated naïve, control-normothermia, asphyxia-normothermia (20-min 4%O2-20%CO2 ventilation; Tcore = 38.5 °C), asphyxia-hypothermia (A-HT, Tcore = 33.5 °C, 2-36 h post-asphyxia), A-HT + H2, or A-HT + CO2 treatment groups. Asphyxia elicited severe hypoxia (pO2 = 19 ± 5 mmHg) and mixed acidosis (pH = 6.79 ± 0.10). HIE development was confirmed by altered cerebral electrical activity and neuropathology. TH was significantly neuroprotective in the caudate nucleus but demonstrated virtually no such effect in the hippocampus. The mRNA levels of apoptosis-inducing factor and caspase-3 showed a ~10-fold increase in the A-HT group compared to naïve animals in the hippocampus but not in the caudate nucleus coinciding with the region-specific neuroprotective effect of TH. H2 or CO2 did not augment TH-induced neuroprotection in any brain areas; rather, CO2 even abolished the neuroprotective effect of TH in the caudate nucleus. In conclusion, the present findings do not support the use of these medical gases to supplement TH in HIE management.